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Sample records for hamstring tendons graft

  1. Isokinetic and anterior cruciate ligament reconstruction with hamstrings or patella tendon graft: analysis of literature.

    PubMed

    Dauty, M; Tortellier, L; Rochcongar, P

    2005-09-01

    We report isokinetic results of anterior cruciate ligament reconstruction with patellar tendon or hamstring graft from the literature analysis. The literature was defined from two search "textwords": Isokinetic and Anterior cruciate ligament reconstruction, and from three databases: Medline, Pascal, and Herasmus. Two independent physicians (Physical Medicine and Rehabilitation) carried out an analysis according to the French National Accreditation and Health Evaluation Agency recommendations. Fifty-three studies were selected: 29 reported isokinetic results after anterior cruciate ligament reconstruction with patellar tendon graft, 15 reported isokinetic results after anterior cruciate ligament reconstruction with hamstring graft, and 9 studies compared the two surgical procedures. After discussing different bias and in reference to prospective randomised and comparative studies, the anterior cruciate ligament reconstruction with patellar tendon graft involves a knee extensors deficit during several months. The hamstring surgical procedure involves a less important knee extensor deficit (from 6 to 19 % against 8 to 21 %). Knee sprain and intra-articular surgery involve a long-lasting knee extensors deficit. Anterior cruciate ligament reconstruction with hamstrings graft involves a knee flexors deficit over several months. The patellar tendon surgical procedure involves a less important knee flexors deficit (from 1 to 15 % against 5 to 17 %). In reference to isokinetic parameters, no difference between the two surgical procedures (patellar tendon graft or hamstring graft) is shown after more than twenty-four post-surgical months. PMID:16195995

  2. Patellar tendon or hamstring graft anterior cruciate ligament reconstructions in patients aged above 50 years

    PubMed Central

    Bali, Tarun; Nagraj, Raghu; Kumar, Malhar N; Chandy, Thomas

    2015-01-01

    Background: The treatment of anterior cruciate ligament (ACL) injury consists of arthroscopic ACL reconstruction with patellar tendon or hamstring graft. Satisfactory results have been reported so far in the younger age group. Dilemma arises regarding the suitability of ACL reconstruction in patients aged 50 years and above. This retrospective analyses the outcome of ACL reconstruction in patients aged 50 years and above. Materials and Methods: 55 patients aged 50 years and above presented to our institution with symptomatic ACL tear and were managed with arthroscopic reconstruction with patellar tendon/hamstring graft. 22 patients underwent ACL reconstruction with bone- patellar tendon-bone graft and the remaining 33 with a hamstring graft. Evaluation of functional outcome was performed using International Knee Documentation Committee (IKDC) and Lysholm scoring in the preoperative period, at the end of 1 year and at the final followup. Radiographic evaluation was performed using the Kellgren–Lawrence grading system. Results: The mean preoperative IKDC score was 39.7 ± 3.3. At the end of 1-year following the operation, the mean IKDC score was 73.6 ± 4.9 and at the final followup was 67.8 ± 7.7. The mean preoperative Lysholm score was 40.4 ± 10.3. At the end of 1-year following the intervention, the mean Lysholm score was 89.7 ± 2.1 and at final followup was 85.3 ± 2.5. Overall, 14 out of 42 patients who underwent radiographic assessment showed progression of osteoarthritis changes at the final followup after the intervention. Conclusion: In our study, there was a statistically significant improvement in the IKDC and Lysholm scores following the intervention. There was a slight deterioration in the scores at the final followup but the overall rate of satisfaction was still high and most of the patients were able to do their routine chores and light exercises suitable for their age group. Around one-third of patients show progression of radiographic changes

  3. Fifteen Year Prospective Comparison of Patellar & Hamstring Tendon Grafts for ACL Reconstruction

    PubMed Central

    Roe, Justin; Salmon, Lucy; Kok, Alison; Linklater, James; Pinczewski, Leo

    2016-01-01

    Objective: This prospective longitudinal study compares isolated endoscopic ACL reconstruction utilizing 4-strand hamstring tendon (HT) or patellar tendon (PT) autograft over a 15-year period with respect to clinical outcomes and the development of osteoarthritis. Method: 90 consecutive patients with isolated ACL rupture were reconstructed with a PT autograft and 90 patients received HT autograft, with an identical surgical technique. Patients were assessed at 2, 5, 7, 10 and 15 years. Assessment included the IKDC Knee Ligament Evaluation including radiographic evaluation, KT1000, kneeling pain, and clinical outcomes. Results: Subjects who received the PT graft had significantly worse outcomes at 15 years for the variables of radiologically detectable osteoarthritis (p=0.001), motion loss (p=0.02), single leg hop test (p=0.002), participation in strenuous activity (p=0.03), knee related decrease in activity level (p=0.002) and kneeling pain (p=0.03). There was no significant difference between the HT and PT groups in overall IKDC grade (p=0.28). ACL graft rupture occurred in 16% of HT group and 8% of the PT group (p=0.10). Contralateral ACL rupture occurred in significantly more PT patients (24%) than HT patients (12%) (p=0.03). Conclusion: Significant differences have developed at 15 years after surgery which were not seen at earlier reviews. Compared to the HT Group, the PT group had significantly worse outcomes with respect to radiological osteoarthritis, range of motion and functional tests but no significant difference in laxity was identified. There was a high incidence of ACL injury after reconstruction, to both the reconstructed and the contralateral knee.

  4. Adequacy of Semitendinosus Tendon Alone for Anterior Cruciate Ligament Reconstruction Graft and Prediction of Hamstring Graft Size by Evaluating Simple Anthropometric Parameters

    PubMed Central

    Stergios, Papastergiou G.; Georgios, Konstantinidis A.; Konstantinos, Natsis; Efthymia, Papathanasiou; Nikolaos, Koukoulias; Alexandros, Papadopoulos G.

    2012-01-01

    Introduction. Preoperative identification of patients with inadequate hamstring grafts for anterior cruciate ligament reconstruction is still a subject of interest. Purpose. The purpose of this study was to determine whether the semitendinosus tendon length is adequate for four-strand graft harvested by common technique (without bone plug) and whether there is correlation of gracilis and semitendinosus tendon grafts length and diameter of quadrupled graft with anthropometric parameters. Materials and Methods. In this retrospective study, 61 patients (45 males, 16 females) undergoing ACL reconstruction using four-strand hamstring autograft tendons were included. Results. The length of semitendinosus tendon, harvested by the common technique, was in 21% of our cases inadequate in order to be used alone as a four-strand graft especially in females (43%). There was moderate correlation between semitendinosus and gracilis graft diameter and patient's height and weight and fair correlation to BMI. We found no statistically important predictor for graft diameter in female patients. Conclusions. The length of semitendinosus tendon, harvested by common technique, is usually inadequate to be used alone as a four-strand graft especially in females. The most reliable predictor seems to be patient's height in males. In female patients, there is no statistically important predictor. PMID:22900187

  5. In vivo determination of knee kinematics in patients with a hamstring or patellar tendon ACL graft.

    PubMed

    Mahfouz, Mohamed R; Traina, Steven M; Komistek, Richard D; Dennis, Douglas A

    2003-10-01

    Video fluoroscopy was used to assess the in vivo kinematics for patients with a patellar-tendon-bone or double-looped semitendinosus gracilis anterior cruciate ligament (ACL) graft. Patients with a double-looped semitendinosus gracilis ACL graft experienced kinematic patterns more similar to the normal knee than patients with a patellar-tendon-bone reconstruction. Patients with a double-looped semitendinosus gracilis reconstruction also experienced more anterior contact at full extension and throughout the flexion cycle than patients with a patellar-tendon-bone reconstruction, which resulted in patients with double-looped semitendinosus gracilis grafts experiencing more posterior femoral rollback. Therefore, removal of the central third of the patella ligament leads to a decrease in quadriceps mechanism efficiency, which resulted in the more posterior contact positions demonstrated by the patients with patellar-tendon-bone grafts in this study. PMID:14584831

  6. Arthroscopic single-bundle posterior cruciate ligament reconstruction: retrospective review of hamstring tendon graft versus LARS artificial ligament

    PubMed Central

    Li, Bin; Wen, Yu; Qian, Qirong; Wu, Yuli; Lin, Xiangbo

    2008-01-01

    Our objective was to compare the results of reconstruction of isolated chronic posterior cruciate ligament (PCL) injury using a four-strand hamstring graft (4SHG) and a LARS artificial ligament. Thirty-six patients were divided into a 4SHG group (n = 15) and a LARS group (n = 21). The minimum follow-up time was two years. The outcome measures used were KT-1000 measurements, the International Knee Documentation Committee (IKDC) scoring system, Lysholm knee scoring scale and Tegner activity rating. Both groups improved significantly between the preoperative and postoperative assessment in terms of the knee laxity and functional examination (P < 0.01). Meanwhile, knee stability was significantly improved in the LARS group when compared with the 4SHG group (P < 0.05); this was also the case for the Lysholm, Tegner and IKDC scores (P < 0.05). Our study indicates that using a LARS ligament for PCL reconstruction was clinically more useful than using a 4SHG in the treatment of the PCL-deficient knee. PMID:18654776

  7. Graft Diameter matters in Hamstring ACL reconstruction

    PubMed Central

    Clatworthy, Mark

    2016-01-01

    Objective: Recently techniques have been developed to increase graft diameter in hamstring ACL reconstruction with the hope to decrease graft failure. To date there is limited evidence to show that a smaller graft diameter results in a higher ACL failure rate. Method: The factors for failure in 1480 consecutive single surgeon hamstring ACL reconstructions were evaluated prospectively. Patients were followed for 2-15 years. A multivariate analysis was performed which looked at graft size, age, sex, time to surgery, meniscal integrity, meniscal repair and ACL graft placement to determine whether graft diameter matters in determining the failure of hamstring ACL reconstruction. Results: Graft diameters ranged from 6-10 mm. The mean graft diameter for all patients was 7.75 mm. 83 ACL reconstructions failed. The mean size of graft failures was 7.55 mm ACL reconstructions that failed had a significantly smaller hamstring graft diameter p=0.001. The Hazard Ratio for a smaller diameter graft is 0.517 p=<0.0001. For every 1 mm decrease in graft diameter there is a 48.3% higher chance of failure. The multivariate analysis showed a hazard ratio of 0.543 p=0.002. For every 1 mm decrease in graft diameter there is a 45.7% higher chance of failure. Conclusion: Smaller diameter hamstring grafts do have a higher failure rate. Grafts ≤ 7.5 mm had twice the failure rate of grafts ≥8 mm using a multivariate analysis for every 1 mm decrease in graft diameter there is a 45.7% higher chance of failure.

  8. Hamstring graft size and anthropometry in south Indian population

    PubMed Central

    Challa, Supradeeptha; Satyaprasad, Jonnalagedda

    2013-01-01

    Background and Aim The role of anthropometric measurements in the prediction of hamstring autograft size in Indian population remains unclear. Till now, no studies have been done on Indian population. Methods We evaluated 41 consecutive patients (34 males, 7 females) prospectively with anterior cruciate ligament deficiency scheduled for reconstruction using hamstring autograft at our institution between June 2011 and June 2013. Preoperatively we recorded age, gender, height, weight, body mass index, and activity level. Intraoperative measurements of semitendinosus tendon like absolute length, diameter before fashioning the graft and final diameter of the tripled graft using sizing tubes calibrated to 1 mm. Correlation coefficient (Pearson's r) analysis was used. Results As per study there is no correlation between graft diameter, age, sex, weight, activity, and body mass index, of patients. Height of patients correlated to graft diameter in both Indian men and women (p < 0.001). Conclusion Anthropometric measurements such as weight, gender, activity level cannot be used as definitive predictors for the hamstring graft diameter during harvest but height of the patients can be taken as good predictor in Indian population. PMID:26403553

  9. Predicting Hamstring Graft Diameter Using MRI and Anthropometry

    PubMed Central

    Fritsch, Brett A; Mhaskar, Vikram A; An, Vincent Vinh Gia; Scholes, Corey

    2016-01-01

    Objectives: Graft diameter is one variable that may affect outcome of ACL reconstruction. The ability to predict the size of a graft in a given patient pre-operatively may help guide graft selection and preparation technique. Various papers have correlated anthropometric data and MRI tendon measurements to intraoperative graft diameter, although no papers have investigated these together. The intra-operative diameter of a hamstring autograft will be influenced by graft preparation technique. Our study aimed to investigate the prediction of intraoperative graft diameter of 2 different graft construct techniques (4-strand semitendinosus versus quadrupled semitendinosus) using anthropometry and MRI measurements. Methods: Retrospective review of two groups of ACL reconstruction using different graft preparation techniques was performed. “Conventional” 4-strand gracilis + semitendinosus with fixed suspension at the femur and screw fixation at the tibia were compared with quadrupled semitendinosus grafts with adjustable suspensory fixation at each end (Graftlink). Cross-sectional areas (XSA) of the semitendinosus and gracilis tendons was measured in the axial slice of a T2 weighted MRI image using a region-of-interest tool. Stepwise linear regression using intraoperative graft diameter as the dependant variable was performed using MRI XSA of the semitendinosus and gracilis tendons, gender and height as predictors. Results: 129 ACL Reconstruction in 127 patients were done in the time period, 89 of which were done conventionally, and 40 which employed the Graftlink construct. The median graft diameter in the Graftlink group (8.5mm IQR8-9) was greater than that of the conventional group (8mm, IQR 7.5-8) (p < 0.001). MRI XSA of semitendinosus and height were statistically significant predictors of diameter in the Graftlink group (R2 = 51%), whilst MRI XSA of semitendinosus + gracilis and gender were predictors in the conventional group (R2 = 36%). Conclusion: Graftlink

  10. Anterior Cruciate Ligament Reconstruction Using Hamstring Tendon Autograft With Preserved Insertions.

    PubMed

    Gupta, Ravi; Bahadur, Raj; Malhotra, Anubhav; Masih, Gladson David; Gupta, Parmanand

    2016-04-01

    We present a technique for anterior cruciate ligament (ACL) reconstruction using hamstring tendon autograft with preserved tibial insertions. The tendons, harvested with an open-ended tendon stripper while their tibial insertions are preserved, are looped around to prepare a quadrupled graft. The femoral tunnel is drilled independently through a transportal technique, whereas the tibial tunnel is drilled in a standard manner. The length of the quadrupled graft and loop of the RetroButton is adjusted so that it matches the calculated length of both tunnels and the intra-articular part of the proposed ACL graft. After the RetroButton is flipped, the graft is manually tensioned with maximal stretch on the free end, which is then sutured to the other end with preserved insertions. We propose that preserving the insertions is more biological and may provide better proprioception. The technique eliminates the need for a tibial-side fixation device, thus reducing the cost of surgery. Furthermore, tibial-side fixation of the free graft is the weakest link in the overall stiffness of the reconstructed ACL, and this technique circumvents this problem. Postoperative mechanical stability and functional outcome with this technique need to be explored and compared with those of ACL reconstruction using free hamstring autograft. PMID:27354946

  11. [Isokinetic assessment with two years follow-up of anterior cruciate ligament reconstruction with patellar tendon or hamstring tendons].

    PubMed

    Condouret, J; Cohn, J; Ferret, J-M; Lemonsu, A; Vasconcelos, W; Dejour, D; Potel, J-F

    2008-12-01

    This retrospective multicentric study was designed to assess the outcome of quadriceps and hamstrings muscles two years after Anterior Cruciate Ligament (ACL) reconstruction and compare muscles recovery depending on the type of graft and individual variables like age, gender, level of sport, but also in terms of discomfort, pain and functional score. The results focused on the subjective and objective IKDC scores, SF36, the existence or not of subjective disorders and their location. The review included isokinetic muscle tests concentric and eccentric extensors/flexors but also internal rotators/external rotators with analysis of mean work and mean power. One hundred and twenty-seven patients were included with an average age 29 years (+/-10). They all had an ACL reconstruction with patellar tendon or hamstring tendon with single or double bundles. In the serie, the average muscles deficit at two years was 10% for the flexors and extensors but with a significant dispersion. Significant differences were not noted in the mean values of all parameters in term of sex or age (over 30 years or not), neither the type of sport, nor of clinical assessment (Class A and B of objective IKDC score), nor the existence of anterior knee pain. There was a relationship between the level of extensor or flexor recovery and the quality of functional results with minimal muscle deficits close to 5% if the IKDC score was over 90 and deficits falling to 15% in the group with IKDC score less than 90. The type of reconstruction (patellar tendon versus hamstrings) had an influence on the muscle deficit. For extensors, the recovery was the same in the two groups, more than 90% at two years and the distribution of these two populations by level of deficit was quite the same. For flexors, residual deficits were significantly higher in the hamstrings group on the three studied parameters whatever the speed and the type of contraction (concentric or eccentric) with an average deficit of 14 to 18

  12. Saphenous nerve injury during harvesting of one or two hamstring tendons for anterior cruciate ligament reconstruction☆

    PubMed Central

    de Padua, Vitor Barion Castro; Nascimento, Paulo Emílio Dourado; Silva, Sergio Candido; de Gusmão Canuto, Sergio Marinho; Zuppi, Guilherme Nunes; de Carvalho, Sebastião Marcos Ribeiro

    2015-01-01

    Objective The aim of this study was to assess whether harvesting of two hamstring tendons (semitendinosus and gracilis) has the same rate of nerve injury as harvesting of the semitendinosus tendon alone, used as a triple graft. Methods Changes in sensitivity relating to injury of the infrapatellar branch of the saphenous nerve were evaluated in 110 patients six months after they underwent anterior cruciate ligament (ACL) reconstruction using hamstring tendons. They were divided into two groups: one in which only the semitendinosus was used and the other, the semitendinosus and gracilis. Results The group in which only the semitendinosus was used as a graft presented a nerve injury rate of 36.1%. In the group in which the semitendinosus and gracilis tendons were used, 58.1% of the patients presented altered sensitivity. In the general assessment on all the patients, the nerve injury rate was 50.9%. Conclusion Harvesting the semitendinosus alone and using it in triple form is a viable option for ACL reconstruction and may give rise to fewer nerve injuries relating to branches of the saphenous nerve. PMID:26535201

  13. Inducement of tissue regeneration of harvested hamstring tendons in a rabbit model

    PubMed Central

    Soejima, T.; Murakami, H.; Noguchi, K.; Shiba, N.; Nagata, K.

    2016-01-01

    Objectives The objective of this study was to determine if the use of fascia lata as a tendon regeneration guide (placed into the tendon canal following harvesting the semitendinosus tendon) would improve the incidence of tissue regeneration and prevent fatty degeneration of the semitendinosus muscle. Materials and Methods Bilateral semitendinosus tendons were harvested from rabbits using a tendon stripper. On the inducing graft (IG) side, the tendon canal and semitendinosus tibial attachment site were connected by the fascia lata, which was harvested at the same width as the semitendinosus tendon. On the control side, no special procedures were performed. Two groups of six rabbits were killed at post-operative weeks 4 and 8, respectively. In addition, three healthy rabbits were killed to obtain normal tissue. We evaluated the incidence of tendon tissue regeneration, cross-sectional area of the regenerated tendon tissue and proportion of fatty tissue in the semitendinosus muscle. Results At post-operative week 8, the distal end of the regenerated tissue reached the vicinity of the tibial insertion on the control side in two of six specimens. On the IG side, the regenerated tissue maintained continuity with the tibial insertion in all specimens. The cross-sectional area of the IG side was significantly greater than that of the control side. The proportion of fatty tissue in the semitendinosus muscle on the IG side was comparable with that of the control side, but was significantly greater than that of the normal muscle. Conclusions Tendon tissue regenerated with the fascia lata graft was thicker than naturally occurring regenerated tissue. However, the proportion of fatty tissue in the semitendinosus muscle was greater than that of normal muscle. Cite this article: K. Tabuchi, T. Soejima, H. Murakami, K. Noguchi, N. Shiba, K. Nagata. Inducement of tissue regeneration of harvested hamstring tendons in a rabbit model. Bone Joint Res 2016;5:247–252. DOI: 10

  14. Anatomical considerations in hamstring tendon harvesting for anterior cruciate ligament reconstruction

    PubMed Central

    Charalambous, Charalambos Panayiotou; Kwaees, Tariq Adam

    2012-01-01

    Summary Hamstring tendons are widely used for anterior cruciate ligament (ACL) reconstruction of the knee. Certain anatomical considerations must be taken into account when harvesting the hamstring tendons to be used in ACL reconstruction. These anatomical considerations are discussed in this review article. PMID:23738306

  15. COMPARATIVE STUDY OF ACL RECONSTRUCTION WITH ANATOMICAL POSITIONING OF THE TUNNELS USING THE PATELLAR TENDON VERSUS HAMSTRING TENDON

    PubMed Central

    de Pádua, Vitor Barion Castro; Maldonado, Hilário; Vilela, Júlio César Rodrigues; Provenza, Alexandre Ribeira; Monteiro, Cleverson; de Oliveira Neto, Heleno Cavalcante

    2015-01-01

    Objective: To compare ACL reconstruction with anatomical positioning of the tunnels using the hamstring or patellar tendons. Methods: We prospectively evaluated 52 patients who underwent ACL reconstruction using the Chambat's technique, with anatomical positioning of the tunnels drilled outside in. They were divided into group A, with 27 patients, using the patellar tendon as a graft, and group B, with 25 patients, using the hamstring. Results: In group A 26 patients were very satisfied or satisfied and 1 unhappy, in group B. 25 patients were very satisfied or satisfied with the procedure (p = 0.990). According to the Lysholm scale, group A had a mean score of 96.11 and group B, 95.32 (p=0.594). In relation to preoperative IKDC, 100% of the patients in group A and 92% of those in group B were IKDC C or D (p = 0.221); in the assessment with a minimum of two-year follow-up, 96% of group A and 92% of group B were IKDC A or B (p = 0.256). The Lachman test, pivot shift, return to sports activities, and the comparative difference in anterior translation (RolimeterTM) also showed no statistically significant difference. In group A, 5 patients (18.5%) were unable to kneel on a hard surface, whereas no patient in group B had this complaint. Conclusion: The anterior cruciate ligament reconstruction presents similar results using the hamstring or patellar tendon with anatomical positioning of the tunnels. Drilling the femoral tunnel outside in is a reproducible and accurate option in the correct placement the femoral tunnel. PMID:27027082

  16. Tibial press-fit fixation of the hamstring tendons for ACL-reconstruction.

    PubMed

    Jagodzinski, M; Scheunemann, K; Knobloch, K; Albrecht, K; Krettek, C; Hurschler, C; Zeichen, J

    2006-12-01

    Press-fit fixation of patellar tendon bone anterior cruciate ligament autografts is an interesting technique because no hardware is necessary to achieve fixation. Up till the present point, there is no biomechanical data available for the tibial press-fit fixation of the hamstring tendons. Hamstring tendons of 21 human cadavers (age: 41.9 +/- 13.1 years) were used. A press-fit fixation with looped semitendinosus and gracilis tendons secured by a tape (T) over a bone bridge, or by a baseball-stitched suture (S), was compared with degradable interference screw fixation (I) in 21 porcine tibiae. The constructs were cyclically strained and subsequently loaded to failure. The maximum load to failure, stiffness, and elongation during cyclical loading were measured. The maximum load to failure was highest for the T-fixation at 970 +/- 83 N, followed by the I-fixation with 544 +/- 109 N, and the S-fixation with 402 +/- 78 N (P < 0.03). Stiffness of the constructs averaged 78 +/- 13 N/mm for T, 108 +/- 18 N/mm for S, and 162 +/- 27 N/mm for I (P < 0.03). Elongation during initial cyclical loading was 2.0 +/- 0.6 mm for T, 3.3 +/- 1.1 mm for S, and 1.4 +/- 0.5 mm for I (S inferior to I and T, P<0.05). Elongation between the 20th and 1,500th loading cycle was lower for T (2.2 +/- 0.7 mm) compared with I (4.1 +/- 2.7 mm) and S (4.8 +/- 0.7 mm; P < 0.001). The T-fixation technique exhibited a significantly higher failure load than the S-, and I- techniques. All techniques exhibited larger elongation during initial cyclical loading than is reported in the literature for grafts with bone blocks. Only one technique (T) showed satisfactory elongation behavior during long-term cyclic loading. Interference screw fixation demonstrated significantly higher stiffness. Only one of the investigated techniques (T) seemed to exhibit adequate mechanical properties necessary for early aggressive rehabilitation programs. PMID:16763851

  17. Role of anthropometric data in the prediction of 4-stranded hamstring graft size in anterior cruciate ligament reconstruction.

    PubMed

    Ho, Sean Wei Loong; Tan, Teong Jin Lester; Lee, Keng Thiam

    2016-03-01

    To evaluate whether pre-operative anthropometric data can predict the optimal diameter and length of hamstring tendon autograft for anterior cruciate ligament (ACL) reconstruction. This was a cohort study that involved 169 patients who underwent single-bundle ACL reconstruction (single surgeon) with 4-stranded MM Gracilis and MM Semi-Tendinosus autografts. Height, weight, body mass index (BMI), gender, race, age and -smoking status were recorded pre-operatively. Intra-operatively, the diameter and functional length of the 4-stranded autograft was recorded. Multiple regression analysis was used to determine the relationship between the anthropometric measurements and the length and diameter of the implanted autografts. The strongest correlation between 4-stranded hamstring autograft diameter was height and weight. This correlation was stronger in females than males. BMI had a moderate correlation with the diameter of the graft in females. Females had a significantly smaller graft both in diameter and length when compared with males. Linear regression models did not show any significant correlation between hamstring autograft length with height and weight (p>0.05). Simple regression analysis demonstrated that height and weight can be used to predict hamstring graft diameter. The following regression equation was obtained for females: Graft diameter=0.012+0.034*Height+0.026*Weight (R2=0.358, p=0.004) The following regression equation was obtained for males: Graft diameter=5.130+0.012*Height+0.007*Weight (R2=0.086, p=0.002). Pre-operative anthropometric data has a positive correlation with the diameter of 4 stranded hamstring autografts but no significant correlation with the length. This data can be utilised to predict the autograft diameter and may be useful for pre-operative planning and patient counseling for graft selection. PMID:26984657

  18. Autologous Hamstring Anterior Cruciate Ligament Graft Failure Using the Anteromedial Portal Technique With Suspensory Femoral Fixation

    PubMed Central

    Galdi, Balazs; Reyes, Allan; Brabston, Eugene W.; Levine, William N.

    2015-01-01

    Background: The anteromedial portal technique for drilling of the femoral tunnel during anterior cruciate ligament (ACL) reconstruction has been advocated by many surgeons as allowing improved access to the anatomical footprint. Furthermore, suspensory fixation of soft tissue grafts has become popularized because of complications associated with cross-pin fixation. Concerns regarding the use of both have recently arisen. Purpose: To raise awareness of the increased risk of graft failure when using the anteromedial portal technique with suspensory femoral fixation during ACL reconstruction. Study Design: Cohort study; Level of evidence, 3. Methods: From November 1998 to August 2012, a total of 465 primary ACL reconstructions were performed using quadrupled hamstring autograft tendons, with drilling of the femoral tunnel performed via the transtibial portal. Graft fixation on the femur was achieved with cross-pin fixation, while interference screw fixation was used on the tibia. From September 2012 to October 2013, there were 69 reconstructions performed through an anteromedial portal. While there was no change in graft choice, a change was made to using suspensory femoral fixation. No other surgical or postoperative rehabilitation changes were made. Results: During the 14-year period in which ACL reconstructions were performed via the transtibial portal and with cross-pin fixation, 2 graft failures (0.4% failure rate) were reported. After switching to the anteromedial portal with suspensory fixation, 7 graft failures (10.1% failure rate) were reported over a 13-month period. These were 5 male and 2 female patients, with a mean age of 18.8 years—all elite athletes. The same surgical technique was used in all patients, and all patients had at least an 8 mm–diameter graft. Patients were cleared to return to sport at an average of 8.4 months postoperatively, after completing functional performance tests. Of the 7 patients, 6 sustained a rerupture of the graft within

  19. Ulnar Nerve Injury after Flexor Tendon Grafting.

    PubMed

    McCleave, Michael John

    2016-10-01

    A 43-year-old female is presented who underwent a two-stage tendon reconstruction and developed a low ulnar nerve palsy postoperatively. Exploration found that the tendon graft was passing through Guyon's canal and that the ulnar nerve was divided. This is a previously unreported complication. The reconstruction is discussed, the literature reviewed and a guide is given on how to identify the correct tissue plane when passing a tendon rod. PMID:27595967

  20. Tendon graft substitutes-rotator cuff patches.

    PubMed

    Coons, David A; Alan Barber, F

    2006-09-01

    Over the past few years, many biologic patches have been developed to augment repairs of large or complex tendon tears. These patches include both allograft and xenografts. Regardless of their origins, these products are primarily composed of purified type I collagen. Many factors should be considered when choosing an augmentation patch including tissue origin, graft processing, cross-linking, clinical experience, and physical properties. The purpose of this article is to familiarize the sports medicine community with several tendon augmentation grafts: GraftJacket (Wright Medical Technology, Arlington, TN), CuffPatch (Organogenesis, Canton, MA, licensed to Arthrotek, Warsaw, IN), Restore (Depuy, Warsaw, IN), Zimmer Collagen Repair (Permacol) patch (Tissue Science Laboratories Covington, GA, licensed to Zimmer, Warsaw, IN), TissueMend (TEI Biosciences, Boston, MA, licensed to Stryker Howmedica Osteonics, Kalamazoo, MI), OrthoADAPT (Pegasus Biologics, Irvine, CA), and BioBlanket (Kensey Nash, Exton, PA). PMID:17135966

  1. Prediction of quadruple hamstring graft diameter for anterior cruciate ligament reconstruction by anthropometric measurements

    PubMed Central

    Asif, Naiyer; Ranjan, Rahul; Ahmed, Sohail; Sabir, Aamir B; Jilani, Latif Z; Qureshi, Owais A

    2016-01-01

    Background: The literature is scanty regarding the anthropometric predictors on the diameter of quadruple hamstring graft obtained in anterior cruciate ligament (ACL) reconstruction in Indian population. Minimum diameter of the graft for ACL reconstruction should be >7 mm to preclude failure. The objective of this study was to assess the prediction of the hamstring graft diameter by several anthropometric parameters including age, thigh circumference, weight, height and body mass index (BMI). Materials and Methods: 46 consecutive patients who had undergone ACL reconstruction by the same surgeon using quadruple hamstring grafts were evaluated. The age, thigh circumference of the normal side, height, weight and BMI were recorded preoperatively and Pearson correlation was done using these parameters with graft diameter measured intraoperatively. Regression analysis in a stepwise manner was undertaken to assess the influence of individual anthropometric parameters on the graft diameter. Results: There were 44 males and 2 females. Mean age was 29.4 years, mean height was 172.6 cm, mean weight was 70.9 kg, mean BMI was 23.8 kg/m2, mean thigh circumference was 47.1 cm and mean graft diameter was 7.9 mm. There was a positive correlation individually between the thigh circumference and graft diameter obtained (r = 0.8, P < 0.01, n = 46), and between the height and graft diameter (r = 0.8, P < 0.01, n = 46). On the regression analysis thigh circumference and height were found to be significant predictors of graft diameter giving the following equation: Graft diameter (mm) = 0. 079 height (cm) +0.068 thigh circumference (cm) −9.031. Conclusion: Preoperatively using the above equation if graft diameter came out to be <7 mm then alternate options of graft material must be kept in mind in order to prevent failure. PMID:26955176

  2. Patellar tendon and hamstring moment-arms and cross-sectional area in patients with anterior cruciate ligament reconstruction and controls.

    PubMed

    Kellis, Eleftherios; Karagiannidis, Evaggelos; Patsika, Glykeria

    2015-08-01

    The purpose of this study was to examine the moment-arm and cross-sectional area (CSA) of the patellar tendon (PT) and the hamstrings after anterior cruciate ligament (ACL) reconstruction. The right knee of five males who underwent ACL reconstruction with a PT graft and five age-matched controls was scanned using magnetic resonance image scans. Based on three-dimensional (3D) solids of the PT, CSAs and moment-arms of semitendinous (ST), biceps femoris (BF) long head and semimembranosus (SM) were estimated. Analysis of variance indicated no significant group differences in muscle moment-arms (p>0.05). 3D moment-arms of PT, ST and BF were significantly lower than the corresponding 2D values (p < 0.05). The ACL group displayed a significantly higher maximum BF CSA, a lower ST CSA (p < 0.05) but similar PT and SM CSAs compared with controls. It is concluded that any alterations in PT properties 1 year after harvesting do not affect knee muscle moment-arms compared with age-matched controls. Moment-arm estimation differed between 3D and 2D data, although it did not affect comparisons between ACL reconstruction group and controls. Design of rehabilitation programmes should take into consideration a potential alteration in hamstring morphology following surgery with a PT graft. PMID:24460238

  3. How much hamstring graft needs to be in the femoral tunnel? A MOON cohort study

    PubMed Central

    Mariscalco, Michael W.; Magnussen, Robert A.; Mitchell, Joshua; Pedroza, Angela D.; Jones, Morgan H.; Andrish, Jack T.; Parker, Richard D.; Kaeding, Christopher C.; Flanigan, David C.

    2014-01-01

    Background Recent evidence that smaller hamstring graft diameter is associated with increased failure risk following anterior cruciate ligament (ACL) reconstruction has increased the popularity of graft configurations that increase graft diameter at the expense of graft length. A key question is how much graft needs to be in contact with the femoral tunnel to ensure that healing occurs. We hypothesize that no difference in two-year patient-reported outcomes or failure risk exists based on the amount of graft in the femoral tunnel. Methods Through the use of prospectively collected cohort data augmented with retrospective chart review, 120 of 181 consecutive patients (66.3 %) undergoing primary ACL reconstruction with hamstring autograft were evaluated. Patient and surgical factors along with pre-operative and two-year postoperative knee injury and osteoarthritis outcome score (KOOS) and International Knee Documentation Committee (IKDC) scores and whether each patient underwent revision ACL reconstruction during the two-year follow-up period were recorded. Results No differences in two-year patient-reported outcome scores were noted between patients with graft length in the femoral tunnel less than 25 mm and those with graft length in the femoral tunnel of at least 25 mm. Controlling for age, sex, BMI, and femoral tunnel technique, no correlation was noted between KOOS or IKDC scores and either the length of graft in the femoral tunnel or the contact area between the graft and the tunnel. Conclusions Variation of the length of hamstring autograft in the femoral tunnel between 14 and 35 mm does not predict KOOS or IKDC scores at 2 years postoperative. PMID:25984246

  4. Outcome of Simultaneous Arthroscopic Anterior Cruciate Ligament and Posterior Cruciate Ligament Reconstruction With Hamstring Tendon Autograft: A Multicenter Prospective Study

    PubMed Central

    Panigrahi, Ranajit; Kumari Mahapatra, Amita; Priyadarshi, Ashok; Singha Das, Dibya; Palo, Nishit; Ranjan Biswal, Manas

    2016-01-01

    Background: Multiligamentous injuries of knee are a complex problem in orthopaedics. Combined ACL-PCL injuries are uncommon, usually associated with knee dislocations. Extremity vascular status is essential because of possible arterio-venous compromise. These complex injuries require a systematic evaluation and treatment. Single setting simultaneous arthroscopic ACL and PCL reconstruction or a staged approach can be adopted to treat these cases. Objectives: To evaluate functional outcome of simultaneous arthroscopic ACL and PCL reconstruction with hamstring tendon autograft in multiligamentous knee injuries. Patients and Methods: This prospective study was performed on 20 patients with combined ACL-PCL injuries who underwent simultaneous arthroscopic ACL-PCL reconstruction with hamstring tendon. Evaluation of functional outcome was by IKDC and Lysholm-Tegner scores. Results: In 20 patients, mean age 34 years, return to full-time work and to full sports was 8 weeks and 6.2 months respectively. All patients had full range of motion except 2 patients with < 5 degrees flexion loss; 90% had negative Lachmann test; 95% had negative pivot shift and 10% patients had mild posterior drawer at 90 degrees (1+) at final follow up. Mean IKDC score was 90 (range 81 - 94); mean Tegner activity score was 7 and mean Lysholm knee score was 89. 85% returned to preinjury activity level and a 90% satisfaction rate. Conclusions: Simultaneous arthroscopic ACL and PCL reconstructions using hamstring tendon for combined ACL and PCL injuries is a clinically effective, safe, time saving and cost-effective procedure with better patient compliance and reproducible for a timely return of motion, strength, and function with favorable outcome. PMID:27217932

  5. Single-Stage Flexor Tendon Grafting: Refining the Steps.

    PubMed

    Fletcher, Derek R; McClinton, Michael A

    2015-07-01

    Single-stage tendon grafting for reconstruction of zone I and II flexor tendon injuries is a challenging procedure in hand surgery. Careful patient selection, strict indications, and adherence to sound surgical principles are mandatory for return of digital motion. PMID:26026357

  6. Staged tendon grafts and soft tissue coverage

    PubMed Central

    Elliot, David

    2011-01-01

    The objective of the two-staged flexor tendon method is to improve the predictability of final results in difficult problems dealing with tendon reconstruction. This article reviews the evolution and benefits of this procedure. It also considers the use of the technique to help deal with problems requiring pulley and skin reconstruction simultaneously with re-constituting the flexor tendon system. PMID:22022043

  7. A meta-analysis of hamstring autografts versus bone-patellar tendon-bone autografts for reconstruction of the anterior cruciate ligament.

    PubMed

    Li, ShuZhen; Su, Wei; Zhao, Jinmin; Xu, Yinglong; Bo, Zhandong; Ding, Xiaofei; Wei, Qingjun

    2011-10-01

    The objective of this study was to evaluate the effectiveness of hamstring (HT) autografts versus bone-patellar tendon-bone (BPTB) autografts for reconstruction of the anterior cruciate ligament (ACL). We searched the Cochrane Library, MEDLINE, EMBASE and the Chinese Biomedicine Database (CBM) for published randomised clinical trials (RCTs) relevant to ACL reconstruction comparing HT and BPTB autografts. Data analyses were performed with Cochrane Collaboration's RevMan 5.0. A total of 23 reports of 19 randomised controlled trials (RCTs) (1643 patients) met the inclusion criteria. Outcomes favouring BPTB autografts were found in terms of KT-1000 arithmometer values, negative rates of Lachman tests and negative rates of Pivot tests. Outcome measures that favoured HT autografts included anterior knee pain, kneeling pain and extension loss. There was no statistical difference of postoperative graft failure. Overall, postoperative complications of the knee joint were lower for HT autografts than for BPTB autografts, and BPTB autografts were superior to HT autografts in resuming stability of the knee joint, but four-strand HT combined with application of the modern endobutton HT graft-fixation technique could increase knee-joint stability. PMID:20850327

  8. Tendon grafts: their natural history, biology and future development.

    PubMed

    Wong, R; Alam, N; McGrouther, A D; Wong, J K F

    2015-09-01

    The use of tendon grafts has diminished as regimes of primary repairs and rehabilitation have improved, but they remain important in secondary reconstruction. Relatively little is known about the cellular biology of grafts, and the general perception is that they have little biological activity. The reality is that there is a wealth of cellular and molecular changes occurring with the process of engraftment that affect the quality of the repair. This review highlights the historical perspectives and modern concepts of graft take, reviews the different attachment techniques and revisits the biology of pseudosheath formation. In addition, we discuss some of the future directions in tendon reconstruction by grafting, which include surface modification, vascularized tendon transfer, allografts, biomaterials and cell-based therapies. PMID:26264585

  9. Silastic tendon graft: its role in neglected tendon repair.

    PubMed

    LaBarbiera, A P; Solitto, R J

    1990-01-01

    A case history is presented of the repair of a neglected traumatic tendon laceration by the use of a permanent Silastic tendon implant, originally manufactured for hand surgery by a staged procedure. Stage I consists of implantation of the Silastic implant and allowance of a 2- to 3-month period for the production of a pseudosheath. Stage II consists of removal of the implant after using it to guide an auto- or allograft, through the newly formed pseudosheath for attachment to the anastomotic sites. PMID:2258563

  10. Acromioclavicular joint reconstruction using a tendon graft: a biomechanical study comparing a novel “sutured throughout” tendon graft to a standard tendon graft

    PubMed Central

    Naziri, Qais; Williams, Nadine; Hayes, Westley; Kapadia, Bhaveen H.; Chatterjee, Dipal; Urban, William P.

    2016-01-01

    Background: With a recurrence rate of over 30%, techniques that offer stronger acromioclavicular (AC) joint reconstruction through increased graft strength may provide longevity. The purpose of our study was to determine the biomechanical strength of a novel tendon graft sutured throughout compared to a native tendon graft in Grade 3 anatomical AC joint reconstruction. Methods: For this in vitro experiment, nine paired (n = 18) embalmed cadaveric AC joints of three males and six females (age 86 years, range 51–94 years) were harvested. Anatomic repair with fresh bovine Achilles tendon grafts without bone block was simulated. Specimens were divided into two groups; with group 1 using grafts with ultra-high molecular-weight polyethylene (UHMWPE) suture ran throughout the entire length. In group 2, reconstruction with only native allografts was performed. The distal scapula and humerus were casted in epoxy compound and mounted on the mechanical testing machine. Tensile tests were performed using a mechanical testing machine at the rate of 50 mm/min. Maximum load and displacement to failure were collected. Results: The average load to failure was significantly higher for group 1 compared to group 2, with mean values of 437.5 N ± 160.7 N and 94.4 N ± 43.6 N, (p = 0.001). The average displacement to failure was not significantly different, with 29.7 mm ± 10.6 mm in group 1 and 25 mm ± 9.1 mm in group 2 (p = 0.25). Conclusion: We conclude that a UHMWPE suture reinforced graft can provide a 3.6 times stronger AC joint reconstruction compared to a native graft. PMID:27163106

  11. Minimally invasive posterior hamstring harvest.

    PubMed

    Wilson, Trent J; Lubowitz, James H

    2013-01-01

    Autogenous hamstring harvesting for knee ligament reconstruction is a well-established standard. Minimally invasive posterior hamstring harvest is a simple, efficient, reproducible technique for harvest of the semitendinosus or gracilis tendon or both medial hamstring tendons. A 2- to 3-cm longitudinal incision from the popliteal crease proximally, in line with the semitendinosus tendon, is sufficient. The deep fascia is bluntly penetrated, and the tendon or tendons are identified. Adhesions are dissected. Then, an open tendon stripper is used to release the tendon or tendons proximally; a closed, sharp tendon stripper is used to release the tendon or tendons from the pes. Layered, absorbable skin closure is performed, and the skin is covered with a skin sealant, bolster dressing, and plastic adhesive bandage for 2 weeks. PMID:24266003

  12. Effects of Gaps Induced Into the ACL Tendon Graft on Tendon-Bone Healing in a Rodent ACL Reconstruction Model

    PubMed Central

    Lovric, Vedran; Kanazawa, Tomonoshin; Nakamura, Yoshinari; Oliver, Rema A.; Yu, Yan; Walsh, William Robert

    2011-01-01

    Summary Graft necrosis following ACL reconstruction is often associated with the use of autologous grafts. Host cells rather than graft cells contribute to the repair of the tendon-bone interface and the remodeling of the autologous graft. The native tendon-bone interface is not recreated and the biomechanical properties are not restored back to native values. We examined the effects of introducing gaps within the tendon graft prior to ACL reconstruction in a rodent model. We hypothesised that gaps will make physical way for host cells to infiltrate and repopulate the graft and thus enhance healing. Animals were sacrificed at seven, fourteen, and twenty-eight days for biomechanical testing and histology. Our findings indicate that graft necrosis, usually observed in the initial two weeks of the healing process, is averted. Histological observations showed that tendon-bone healing stages were hastened however this didn’t translate into improved biomechanical properties. PMID:23738254

  13. ‘Serious thigh muscle strains’: beware the intramuscular tendon which plays an important role in difficult hamstring and quadriceps muscle strains

    PubMed Central

    Brukner, Peter; Connell, David

    2016-01-01

    Why do some hamstring and quadriceps strains take much longer to repair than others? Which injuries are more prone to recurrence? Intramuscular tendon injuries have received little attention as an element in ‘muscle strain’. In thigh muscles, such as rectus femoris and biceps femoris, the attached tendon extends for a significant distance within the muscle belly. While the pathology of most muscle injures occurs at a musculotendinous junction, at first glance the athlete appears to report pain within a muscle belly. In addition to the musculotendinous injury being a site of pathology, the intramuscular tendon itself is occasionally injured. These injuries have a variety of appearances on MRIs. There is some evidence that these injuries require a prolonged rehabilitation time and may have higher recurrence rates. Therefore, it is important to recognise the tendon component of a thigh ‘muscle strain’. PMID:26519522

  14. [Long-term follow up of anterior cruciate ligament reconstruction using autologous tendon graft augmented with alloplasty (Kennedy LAD)].

    PubMed

    Riel, K A; Bernett, P

    1990-11-01

    From October 1983 to January 1990 in 493 patients 499 injured anterior cruciate ligaments were reconstructed by a composite tendon graft. The autogenous graft, semitendinosus tendon or quadriceps-patella periost-patellar tendon, both anatomically attached distally, was augmented with the polypropylene braid (Kennedy LAD). In the period of January to November 1984 in 81 patients anterior cruciate ligament replacement was performed. A retrospective 2-years follow-up in 72 patients and a second 5-years follow-up in 67 of those 72 patients was possible. There were 38 patients with an acute rupture and 34 patients with chronic instability. Clinical and instrumented laxity revealed a mean displacement difference of not more than 3 mm in 84% of the patients in comparison of the involved with the normal knee at the 2-years and 5-years follow-up. 80% of strength analyses showed a physiological balance of quadriceps and hamstrings in the 5-years follow-up. In the 2-years follow-up only 41% of patients practiced former sports activities again, whereas in the 5-years follow-up 80% of the patients were able to join former sports. 80 to 100 points of Lysholm score demonstrating good to very good results were reached in 91% of the patients. Especially cartilage damages in cases of chronic instabilities worsened the results mentioned by the patients. PMID:2282840

  15. Applying Cross-Pin System in Both Femoral and Tibial Fixation in Anterior Cruciate Ligament Reconstruction Using Hamstring Tendons

    PubMed Central

    Qi, Wei; Liu, Yujie; Xue, Jing; Li, Haifeng; Wang, Junliang; Qu, Feng

    2015-01-01

    Use of the RigidFix Cross Pin System (DePuy Mitek, Raynham, MA) is a popular technique for femoral fixation of grafts in anterior cruciate ligament reconstruction (ACLR). However, tibial fixation is still limited to the use of interference screws and post fixation, and few surgeons apply the femoral RigidFix system in tibial fixation. Meanwhile, tunnel enlargement is still a problem that affects the outcome of ACLR with hamstring grafts. We have used the femoral RigidFix system in femoral and tibial fixation. The rod top of the guide frame should be placed under the level of the subchondral bone at the proximal end of the tibial tunnel to ensure that the pins will not be inserted into the joint. The pins are inserted through the center of the lateral tibia. Using our technique, the fixation points of the femur and tibia are close to the anterior cruciate ligament insertions, and full contact of the graft with the tunnel wall can be accomplished. On the basis of our preliminary observations and investigation, we are optimistic about the prospect of performing ACLR using the RigidFix system in femoral and tibial fixation. PMID:26697293

  16. Calcium phosphate-hybridized tendon graft to enhance tendon-bone healing two years after ACL reconstruction in goats

    PubMed Central

    2011-01-01

    Background We developed a novel technique to improve tendon-bone attachment by hybridizing calcium phosphate (CaP) with a tendon graft using an alternate soaking process. However, the long-term result with regard to the interface between the tendon graft and the bone is unclear. Methods We analyzed bone tunnel enlargement by computed tomography and histological observation of the interface and the tendon graft with and without the CaP hybridization 2 years after anterior cruciate ligament (ACL) reconstruction in goats using EndoButton and the postscrew technique (CaP, n = 4; control, n = 4). Results The tibial bone tunnel enlargement rates in the CaP group were lower than those in the control group (p < 0.05). In the CaP group, in the femoral and tibial bone tunnels at the anterior and posterior of the joint aperture site, direct insertion-like formation that contained a cartilage layer without tidemarks was more observed at the tendon-bone interface than in the control group (p < 0.05). Moreover, the gap area between the tendon graft and the bone was more observed at the femoral bone tunnel of the joint aperture site in the control group than in the CaP group (p < 0.05). The maturation of the tendon grafts determined using the ligament tissue maturation index was similar in both groups. Conclusions The CaP-hybridized tendon graft enhanced the tendon-bone healing 2 years after ACL reconstruction in goats. The use of CaP-hybridized tendon grafts can reduce the bone tunnel enlargement and gap area associated with the direct insertion-like formation in the interface near the joint. PMID:22166674

  17. The effect of accelerated, brace free, rehabilitation on bone tunnel enlargement after ACL reconstruction using hamstring tendons: a CT study.

    PubMed

    Vadalà, Antonio; Iorio, Raffaele; De Carli, Angelo; Argento, Giuseppe; Di Sanzo, Vincenzo; Conteduca, Fabio; Ferretti, Andrea

    2007-04-01

    The mechanism of bone tunnel enlargement following anterior cruciate ligament (ACL) reconstruction is not yet clearly understood. Many authors hypothesized that aggressive rehabilitation protocols may be a potential factor for bone tunnel enlargement, especially in reconstructions performed with hamstrings autograft. The purpose of this study was to evaluate the effect of a brace free rehabilitation on the tunnel enlargement after ACL reconstruction using doubled semitendinosus and gracilis tendons (DGST): our hypothesis was that early post-operative knee motion increase the diameters of the tibial and femoral bone tunnels. Forty-five consecutive patients undergoing ACL reconstruction for chronic ACL deficiency were selected. All patients were operated by the same surgeon using autologous DGST and the same fixation devices. Patients with associated ligaments injuries and or severe chondral damage were excluded. The patients were randomly assigned to enter the control group (group A, standard post-operative rehabilitation) and the study group (group B, brace free accelerated rehabilitation). A CT scan was used to exactly determine the diameters of both femoral and tibial tunnels at various levels of lateral femoral condyle and proximal tibia, using a previously described method [17]. Measurements were done by an independent radiologist in a blinded fashion the day after the operation and at a mean follow-up of 10 months (range 9-11). Statistical analysis was performed using paired t-test. The mean femoral tunnel diameter increased significantly from 9.04 +/- 0.05 (post-operative) to 9.30 +/- 0.8 mm (follow-up) in group A and from 9.04 +/- 0.03 to 9.94 +/- 1.12 mm in group B. The mean tibial tunnel diameter increased significantly from 9.03 +/- 0.04 to 10.01 +/- 0.80 mm in group A and from 9.04 +/- 0.03 to 10.60 +/- 0.78 mm in group B. The increase in femoral and tunnel diameters observed in the study group was significantly higher than that observed in the control

  18. Does Choosing Autograft Hamstring vs. Patellar Tendon by Gender, Sport, Level of Competition or Laxity in High School and College Aged Athletes Improve KOOS, IKDC or Marx?

    PubMed Central

    Huston, Laura J.; Reinke, Emily; Kattan, Michael W.; Chagin, Kevin; Spindler, Kurt P.

    2016-01-01

    Objectives: Physicians’ and patients’ decision-making process between autograft hamstring (HG) vs. patellar tendon (BTB) for ACL reconstruction (ACLR) may be influenced by patient gender, laxity level, sport played, and/or competition level in the young, active athlete. ACLR specific to high school and college-aged athletes with these aforementioned factors in mind has not been evaluated. Therefore, our objectives were twofold: first, to develop a simple web-based risk calculator as a decision-making aid to provide the best estimate of expected 2-year KOOS, IKDC, and Marx outcomes by gender, sport, level of competition, and knee laxity. Second, to identify whether autograft HG or BTB is the optimal graft choice given any combination of the aforementioned variables. Methods: Our inclusion criteria in the MOON cohort were patients aged 11-22 who were injured in sport (football, soccer, basketball, other), who were due to have a unilateral primary ACLR with either an autograft HG or BTB, and who had a contralateral normal knee. Excluded were revisions, allografts, those with a contralateral ACLR and concomitant MCL/LCL/PCL surgery. Laxity was graded as increased (Lachman > 10 mm or a pivot lock) or normal based on the EUA. Our modeling controlled for BMI, ethnicity, and baseline measures of patient-reported outcomes. Our two year outcomes were the KOOS knee related quality of life subscale, KOOS sports and recreation subscale, IKDC, and Marx activity level. Our multivariable modeling for risk online calculator and nomograms was generated in two ways. The performances for our models were measured using R squared, calibration curves, and bootstrapping. Results: 937 patients were eligible, 809 (86%) had 2 year follow-up data. The average age was 17, with 50% females, and the distribution of HG to BTB was 301/508 respectively. First, in evaluating our models for ACLR autograft choice, neither KOOS subscale models performed better than chance. The IKDC and Marx models

  19. Anterior Cruciate Ligament Reconstruction With Autologous Hamstring

    PubMed Central

    Grawe, Brian M.; Williams, Phillip N.; Burge, Alissa; Voigt, Marcia; Altchek, David W.; Hannafin, Jo A.; Allen, Answorth A.

    2016-01-01

    Background: Recent clinical investigations have identified inadequate autograft hamstring graft diameter (<8 mm) to be predictive of failure after reconstruction of the anterior cruciate ligament (ACL). Purpose/Hypothesis: The objective of this study was to determine the utility of preoperative magnetic resonance imaging (MRI) variables of the hamstring tendons for the prediction of graft diameter at the time of surgery. The hypothesis was that cross-sectional area (CSA) of the hamstring tendon measured on MRI could accurately predict graft diameter, and threshold measurements could be established to predict graft diameter at the time of surgery. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: A total of 84 consecutive skeletally mature patients prospectively enrolled in our ACL reconstruction patient registry were identified for study purposes. Patients were included if they underwent an MRI of the affected knee at our institution prior to ACL reconstruction with hamstring (HT) autograft. Graft preparation was performed via a standard quadrupled hamstring technique after harvesting both the gracilis and semitendinosus (4-GST). The smallest diameter end of the HT autograft was then utilized for measurement analysis. Total CSA was calculated for both hamstring tendons using the “region of interest tool” on the corresponding proton density–weighted axial image of the knee at the widest condylar dimension. Three independent reviewers measured the MRI scans so that intra- and interrater reliability of the measurements could be determined. A trend analysis was then undertaken to establish correlations between the MRI CSA and graft diameter. Predictive analysis was then performed to establish threshold MRI measurement values for specific graft diameters and determine whether any patient-specific factors would affect graft diameter (age, sex, and body mass index). Results: Mean patient age at the time of surgery was 36 years (range, 11

  20. IMPROVEMENT OF TENDON REPAIR USING MUSCLE GRAFTS TRANSDUCED WITH TGF-β1 cDNA

    PubMed Central

    Majewski, Martin; Porter, Ryan M.; Betz, Oliver B.; Betz, Volker M.; Clahsen, Harald; Flückiger, Rudolf; Evans, Christopher H.

    2015-01-01

    Tendon rupture is a common injury. Inadequate endogenous repair often leaves patients symptomatic, with tendons susceptible to re-rupture. Administration of certain growth factors improves tendon healing in animal models, but their delivery remains a challenge. Here we evaluated the delivery of TGF-β1 to tendon defects by the implantation of genetically modified muscle grafts. Rat muscle biopsies were transduced with recombinant adenovirus encoding TGF-β1 and grafted onto surgically transected Achilles tendons in recipient animals. Tissue regenerates were compared to those of controls by biomechanical testing as well as histochemical and immunohistochemical analyses. Healing was greatly accelerated when genetically modified grafts were implanted into tendon defects, with the resulting repair tissue gaining nearly normal histological appearance as early as 2 weeks postoperatively. This was associated with decreased deposition of type III collagen in favour of large fibre bundles indicative of type I collagen. These differences in tendon composition coincided with accelerated restoration of mechanical strength. Tendon thickness increased in gene-treated animals at weeks 1 and 2, but by week 8 became significantly lower than that of controls suggesting accelerated remodelling. Thus localised TGF-β1 delivery via adenovirus-modified muscle grafts improved tendon healing in this rat model and holds promise for clinical application. PMID:22354460

  1. The role of graft materials in suture augmentation for tendon repairs and reattachment.

    PubMed

    Kummer, Frederick J; Iesaka, Kazuho

    2005-08-01

    Various biomaterials have been used to augment sutures for the repair and reattachment of tendons. This study examined four different graft materials in a simple and reproducible model using chicken Achilles tendons to determine the strength and mechanism of suture reinforcement of tendon repairs. The graft materials tested were Gore-Tex(R) Soft Tissue Patch, Graftjacket, bovine pericardium, and an experimental graft material from Xylos Corporation. Testing was performed in shear to simulate forces on a torn tendon repair and pull-off to simulate those on a tendon reattachment to bone. Compared to unaugmented suture, grafts increased suture fixation strength from 10% to 60% in shear and from 0% to 36% in pull-off with the bovine pericardium graft, providing significant improvement in both tests. In no cases (even unaugmented) did the suture pull directly through the tendon, but instead sliced along it, demonstrating that the interface between the suture and the tendon determines fixation strength. Grafts function by increasing the area, friction, and nature of this interface, not by acting as a barrier for suture pull-through. PMID:15981174

  2. Coracoclavicular ligament reconstruction: biomechanical comparison of tendon graft repairs to a synthetic double bundle augmentation.

    PubMed

    Wellmann, Mathias; Kempka, Jan P; Schanz, Steffen; Zantop, Thore; Waizy, Hazibullah; Raschke, Michael J; Petersen, Wolf

    2009-05-01

    For currently presented anatomical coracoclavicular ligament repairs issues such as autologous tendon graft versus synthetic suture augmentation and the optimum fixation strategies for both types of reconstruction are not solved. The purpose of the study was to compare the biomechanical properties of different tendon graft repairs to the characteristics of a synthetic polyester augmentation. Four anatomical coracoclavicular ligament repairs were biomechanically tested: 5 mm coracoclavicular tendon loop with suture fixation, tendon loop with flip button fixation, tendon loop with interference screw fixation versus a double 1.0-mm polyester repair with flip button fixation. The biomechanical testing included cyclic superio-inferior loading and a subsequent load to failure protocol. The ultimate failure loads were significantly higher for the double polyester/flip button repair (927 N) compared to all tendon repair techniques (maximum 640 N). In contrast the stiffness level was higher for the tendon repairs compared to the polyester/flip button repair (68.7 N/mm) but strongly dependent on the fixation technique (interference screw 97.2 N/mm, flip button 84.9 N/mm, side to side suture 60.9 N/mm). A synthetic coracoclavicular augmentation using a polyester suture provides adequate structural properties compared to a tendon repair. Therefore the decision for a tendon graft should be made by the necessity of a biologic substrate rather than by the assumption of a biomechanical advantage. PMID:19225755

  3. Comparison of short-term results of bone tunnel enlargement between EndoButton CL and cross-pin fixation systems after chronic anterior cruciate ligament reconstruction with autologous quadrupled hamstring tendons.

    PubMed

    Kuskucu, S M

    2008-01-01

    We performed arthroscopic anterior cruciate ligament (ACL) reconstructions of chronic ACL rupture with autologous hamstring tendon grafts in males (mean age 23.9 years). Thirty-two cross-pin fixations and 24 EndoButton CL fixations were performed on the femoral side. Distal fixations on the tibial side were maintained with interference screws plus a staple. Tunnel enlargement was evaluated using X-rays. Femoral and tibial tunnels were measured at three levels 5 mm apart, and average enlargement was calculated after correction for magnification. Tunnel enlargement 12 months after surgery was greater for the EndoButton CL system (femoral side 43.71%, tibial side 51.11%) than for the cross-pin system (femoral side 32.61%, tibial side 25.62%); the difference was significant only on the tibial side. Both proximal fixation techniques were judged clinically successful (follow-up 16 - 36 months). The far fixation point in the EndoButton CL group may be related to mechanical loosening. PMID:18230264

  4. Osteogenic Matrix Cell Sheet Transplantation Enhances Early Tendon Graft to Bone Tunnel Healing in Rabbits

    PubMed Central

    Uematsu, Kota; Akahane, Manabu; Morita, Yusuke; Ogawa, Munehiro; Ueha, Tomoyuki; Shimizu, Takamasa; Kura, Tomohiko; Kawate, Kenji; Tanaka, Yasuhito

    2013-01-01

    The objective of this study was to determine whether osteogenic matrix cell sheets (OMCS) could induce bone formation around grafted tendons, thereby enhancing early stage tendon to bone tunnel healing in skeletally mature male Japanese white rabbits. First, the osteogenic potential of rabbit OMCS was evaluated. Then, the OMCS were transplanted into the interface between the grafted tendon and the bone tunnel created at the tibia. Histological assessments and biomechanical tensile testing were performed after 3 weeks. The rabbit OMCS showed high alkaline phosphatase (ALP) activity, positive staining of ALP, and osteogenic potential when transplanted subcutaneously with beta tricalcium phosphate disks. Newly formed bony walls and positive collagen type I staining were seen around the grafted tendon with OMCS transplantation, whereas such bony walls were thinner or less frequent without OMCS transplantation. Micro-computed tomography images showed significantly higher bone volume in the OMCS transplantation group. The pullout strength was significantly higher with OMCS (0.74 ± 0.23 N/mm2) than without OMCS (0.58 ± 0.15 N/mm2). These results show that OMCS enhance early tendon to bone tunnel healing. This method can be applied to cases requiring early tendon to bone tunnel healing after ligament reconstruction surgery. PMID:24106718

  5. A preliminary study on the effects of acellular tissue graft augmentation in acute Achilles tendon ruptures.

    PubMed

    Lee, Daniel K

    2008-01-01

    Acute Achilles tendon rupture injuries present surgical challenges because of the mechanical forces placed on this tendon. The purpose of this study was to evaluate the effectiveness of an acellular human dermal tissue matrix, GraftJacket Matrix (Wright Medical Technology, Inc., Arlington, TN), as an augmentation material in acute Achilles tendon repair. Eleven consecutive patients with acute tendon ruptures were evaluated and followed up (20-31 months). Primary repair was followed by augmentation with the graft sutured circumferentially around the tendon. Patients were placed in an early functional rehabilitation program with postoperative evaluation at 3, 6, and 12 months. Outcome scores were calculated based on the American Orthopaedic Foot and Ankle Society ankle-hindfoot scoring system. At 20-month postoperative follow-up, there have been no cases of rerupture or recurrent pain. The average return-to-activity time was 11.8 +/- 0.75 weeks. These retrospective clinical results suggest that with an acellular human dermal tissue matrix to augment acute Achilles tendon, primary repair offers a desirable return-to-activity time without any rerupture or complications. ACFAS Level of Clinical Evidence: 2c. PMID:18156058

  6. Minimally Invasive Harvest of a Quadriceps Tendon Graft With or Without a Bone Block

    PubMed Central

    Fink, Christian; Herbort, Mirco; Abermann, Elisabeth; Hoser, Christian

    2014-01-01

    The quadriceps tendon (QT) as a graft source for anterior cruciate ligament (ACL) and posterior cruciate ligament reconstruction has recently achieved increased attention. Although many knee surgeons have been using the QT as a graft for ACL revision surgery, it has never gained universal acceptance for primary ACL reconstruction. The QT is a very versatile graft that can be harvested in different widths, thicknesses, and lengths. Conventionally, the QT graft is harvested by an open technique, requiring a 6 to 8 cm longitudinal incision, which often leads to unpleasant scars. We describe a new, minimally invasive, standardized approach in which the QT graft can be harvested through a 2- to 3-cm skin incision and a new option of using the graft without a bone block. PMID:25264512

  7. Minimally invasive harvest of a quadriceps tendon graft with or without a bone block.

    PubMed

    Fink, Christian; Herbort, Mirco; Abermann, Elisabeth; Hoser, Christian

    2014-08-01

    The quadriceps tendon (QT) as a graft source for anterior cruciate ligament (ACL) and posterior cruciate ligament reconstruction has recently achieved increased attention. Although many knee surgeons have been using the QT as a graft for ACL revision surgery, it has never gained universal acceptance for primary ACL reconstruction. The QT is a very versatile graft that can be harvested in different widths, thicknesses, and lengths. Conventionally, the QT graft is harvested by an open technique, requiring a 6 to 8 cm longitudinal incision, which often leads to unpleasant scars. We describe a new, minimally invasive, standardized approach in which the QT graft can be harvested through a 2- to 3-cm skin incision and a new option of using the graft without a bone block. PMID:25264512

  8. Achilles tendon repair with acellular tissue graft augmentation in neglected ruptures.

    PubMed

    Lee, Daniel K

    2007-01-01

    Neglected Achilles tendon rupture injuries present surgical challenges because of the quality and quantity of tendon tissue during repair combined with the magnitude of mechanical forces placed on this tendon. The purpose of this study was to evaluate the effects of an acellular human dermal tissue matrix, GRAFTJACKET, as an augmentation material in neglected Achilles tendon repair. Nine patients with neglected Achilles tendon ruptures were evaluated and followed up for a minimum of 20 months. Primary repair was followed by augmentation with the graft and suturing circumferentially around the tendon. Patients were placed in an early, functional rehabilitation program with postoperative evaluation at 3, 6, and 12 months. Outcome scores were calculated based on the American Orthopaedic Foot and Ankle Society ankle-hindfoot scoring system. At 20 to 30 months postoperative follow-up range, there has been no incidence of re-rupture or recurrent pain. The average return-to-activity time was 15.2 +/- 1.7 weeks. The results from this retrospective clinical series suggest that using an acellular human dermal tissue matrix to augment neglected Achilles tendon rupture primary repair offers desirable return-to-activity time points and viable surgical alternative over previously reported surgical options. PMID:17980842

  9. ACL reconstruction using bone-tendon-bone graft engineered from the semitendinosus tendon by injection of recombinant BMP-2 in a rabbit model.

    PubMed

    Hashimoto, Yusuke; Naka, Yoshifumi; Fukunaga, Kenji; Nakamura, Hiroaki; Takaoka, Kunio

    2011-12-01

    We attempted to generate a bone-tendon-bone structure by injecting human-type recombinant human bone morphogenetic protein-2 (rhBMP-2) into the semitendinosus tendon, and an anterior cruciate ligament (ACL) defect was reconstructed by grafting the engineered bone-tendon-bone graft. Two ossicles with a separation distance of 1 cm were generated within the left semitendinosus tendon of a rabbit 6 weeks after the injection of rhBMP-2 (15 µg at each site). The engineered bone-tendon-bone graft was transplanted in order to reconstruct the ACL by passing the graft through the bone tunnels. In the control group, the ACL was reconstructed with the semitendinosus tendon without BMP-2 using the same methods as those used in the experimental group. The animals were harvested at 4 or 8 weeks after surgery and examined by radiographic, histological, and biomechanical methods. In the experimental group, ossicles in the bone-tendon-bone graft were successfully integrated into the host bone of the femur and tibia. Histological analysis revealed that characteristic features identical to the normal direct insertion morphology had been restored. Biomechanical pull-out testing showed that the ultimate failure load and stiffness of the reconstructed ACL in the experimental group were significantly higher than those in the control group at both 4 and 8 weeks (p < 0.05). These results indicate the potential of regenerative reconstruction of the ACL, and the reconstruction resulted in the restoration of morphology and function equivalent to those of the normal ACL. PMID:21557301

  10. The effect of butyric acid with autogenous omental graft on healing of experimental Achilles tendon injury in rabbits

    PubMed Central

    Jahani, S; Moslemi, H. R.; Dehghan, M. M.; Sedaghat, R; Mazaheri Nezhad, R; Rezaee Moghaddam, D

    2015-01-01

    In this study, the role of local injection of butyric acid (BA) with autogenous omental graft was evaluated in healing of experimental Achilles tendon injury in rabbits. Nine adult male New Zealand rabbits were anesthetized and a partial thickness tenotomy was created on both hindlimbs. In treated group, omental graft was secured in place using BA soaked polygalactin 910 suture. In control group, the graft was sutured without BA. Butyric acid and normal saline were injected daily to treatment and control groups for three days, respectively. Based on the findings, on day 15 after injury, the tendon sections showed that healing rate in BA treated group was higher than that in control group. Furthermore, at days 28 and 45, comparison between BA treated and control groups demonstrated that BA increased the healing rate but with no significance. In summary, results of this study show that application of BA with autogenous omental graft can improve healing process of damaged Achilles tendon. PMID:27175160

  11. Repair of lacerated anterior tibial tendon with acellular tissue graft augmentation.

    PubMed

    DiDomenico, Lawrence A; Blasko, Gregory A; Cane, Laurence; Cross, Davina J

    2012-01-01

    In the present case report, we describe the surgical repair of a complete laceration of the anterior tibial tendon using acellular human dermal tissue matrix. A 17-year-old, elite league hockey player was injured in the locker room when a teammate still clad in ice skates stepped on his bare left foot. After evaluation at a local emergency department, the patient presented to our office the next day for additional evaluation. It was determined that surgery would be performed using acellular tissue graft augmentation, followed by physical therapy. Within 7 weeks of the injury, the athlete returned to his original level of activity. At 3 years of follow-up, he was playing Division 1 hockey at the university level. We believe that augmentation of the tendon repair with the grafting material enhanced the tendon tensile strength and promoted ingrowth through vascular channels. This, combined with the patient's dedication to physical therapy, led to excellent recovery in less time than anticipated. PMID:22762944

  12. Synthesis, development, characterization and effectiveness of bovine pure platelet gel-collagen-polydioxanone bioactive graft on tendon healing.

    PubMed

    Moshiri, Ali; Oryan, Ahmad; Meimandi-Parizi, Abdolhamid

    2015-06-01

    Bovine platelet gel (BPG) is an accessible and cost-effective source of growth factors which may have a value in tendon regenerative medicine. We produced a collagen implant (CI) as a tendon proper, covered it with polydioxanone (PDS) sheath to simulate paratenon and finally embedded the BPG as an active source of growth factor within the bioimplant to test whether BPG would be able to accelerate and enhance tendon regeneration and repair. After in vitro characterization of the bioactive grafts, the grafts were implanted in rabbit large tendon defect model. Untreated tendons and tendons treated with either CI or CI-PDS were served as controls for the CI-PDS-BPG. The animals were investigated clinically, ultrasonographically and haematologically for 120 days. After euthanasia, dry matter content, water uptake and delivery characteristics and also gross morphological, histopathological and scanning electron microscopic features of the healing tendons were assessed. In vitro, the activated platelets in the scaffold, released their growth factors significantly more than the controls. BPG also increased cell viability, and enhanced cellular differentiation, maturation and proliferation inside the CI-PDS compared with the controls. In vivo, the BPG modulated inflammation, increased quality and rate of fibroplasia and produced a remodelled tendon that had significantly higher collagen content and superior collagen fibril and fibre differentiation than controls. Treatment also significantly improved tendon water uptake and delivery characteristics, animals' serum PDGF level, CI-PDS biocompatibility and biodegradability and reduced peritendinous adhesions, muscle fibrosis and atrophy. BPG was effective on tendon healing and CI-PDS-BPG may be a valuable bioscaffold in tendon reconstructive surgery. PMID:25702535

  13. Synthesis, development, characterization and effectiveness of bovine pure platelet gel-collagen-polydioxanone bioactive graft on tendon healing

    PubMed Central

    Moshiri, Ali; Oryan, Ahmad; Meimandi-Parizi, Abdolhamid

    2015-01-01

    Bovine platelet gel (BPG) is an accessible and cost-effective source of growth factors which may have a value in tendon regenerative medicine. We produced a collagen implant (CI) as a tendon proper, covered it with polydioxanone (PDS) sheath to simulate paratenon and finally embedded the BPG as an active source of growth factor within the bioimplant to test whether BPG would be able to accelerate and enhance tendon regeneration and repair. After in vitro characterization of the bioactive grafts, the grafts were implanted in rabbit large tendon defect model. Untreated tendons and tendons treated with either CI or CI-PDS were served as controls for the CI-PDS-BPG. The animals were investigated clinically, ultrasonographically and haematologically for 120 days. After euthanasia, dry matter content, water uptake and delivery characteristics and also gross morphological, histopathological and scanning electron microscopic features of the healing tendons were assessed. In vitro, the activated platelets in the scaffold, released their growth factors significantly more than the controls. BPG also increased cell viability, and enhanced cellular differentiation, maturation and proliferation inside the CI-PDS compared with the controls. In vivo, the BPG modulated inflammation, increased quality and rate of fibroplasia and produced a remodelled tendon that had significantly higher collagen content and superior collagen fibril and fibre differentiation than controls. Treatment also significantly improved tendon water uptake and delivery characteristics, animals’ serum PDGF level, CI-PDS biocompatibility and biodegradability and reduced peritendinous adhesions, muscle fibrosis and atrophy. BPG was effective on tendon healing and CI-PDS-BPG may be a valuable bioscaffold in tendon reconstructive surgery. PMID:25702535

  14. Bone Tunnel Diameter Measured with CT after Anterior Cruciate Ligament Reconstruction Using Double-Bundle Auto-Hamstring Tendons: Clinical Implications

    PubMed Central

    Yoon, Soo Jeong; Bae, So Young; Wang, Joon Ho

    2015-01-01

    Objective To evaluate the correlation between bone tunnel diameter after anterior cruciate ligament (ACL) reconstruction measured by computed tomography (CT) using multiplanar reconstruction (MPR) and stability or clinical scores. Materials and Methods Forty-seven patients (41 men and 6 women, mean age: 34 years) who had undergone ACL reconstruction with the double bundle technique using auto-hamstring graft and had subsequently received CT scans immediately after the surgery (T1: range, 1-4 days, mean, 2.5 days) and at a later time (T2: range, 297-644 days, mean, 410.4 days) were enrolled in this study. The diameter of each tunnel (two femoral and two tibial) at both T1 and T2 were independently measured using MPR technique by two radiologists. Stability and clinical scores were evaluated with a KT-2000 arthrometer, International Knee Documentation Committee objective scores, and the Lysholm score. Statistical analysis of the correlation between the diameter at T2 or the interval diameter change ratio ([T2 - T1] / T1) and clinical scores or stability was investigated. Results The tibial bone tunnels for the anteromedial bundles were significantly widened at T2 compared with T1 (observer 1, 0.578 mm to 0.698 mm, p value of < 0.001; observer 2, 0.581 mm to 0.707 mm, p value of < 0.001). There was no significant correlation between the diameter at T2 and stability or clinical scores and between the interval change ratio ([T2 - T1] / T1) and stability or clinical scores (corrected p values for all were 1.0). Intraobserver agreement for measurements was excellent (> 0.8) for both observers. Interobserver agreement for measurement was excellent (> 0.8) except for the most distal portion of the femoral bone tunnel for anterior medial bundle in immediate postoperative CT, which showed moderate agreement (concordance correlation coefficient = 0.6311). Conclusion Neither the diameter nor its change ratio during interval follow-up is correlated with stability or clinical

  15. Development of a Surgically Optimized Graft Insertion Suture Technique to Accommodate a Tissue-Engineered Tendon In Vivo

    PubMed Central

    Sawadkar, Prasad; Alexander, Susan; Tolk, Marten; Wong, Jason; McGrouther, Duncan; Bozec, Laurent

    2013-01-01

    Abstract The traumatic rupture of tendons is a common clinical problem. Tendon repair is surgically challenging because the tendon often retracts, resulting in a gap between the torn end and its bony insertion. Tendon grafts are currently used to fill this deficit but are associated with potential complications relating to donor site morbidity and graft necrosis. We have developed a highly reproducible, rapid process technique to manufacture compressed cell-seeded type I collagen constructs to replace tendon grafts. However, the material properties of the engineered constructs are currently unsuitable to withstand complete load bearing in vivo. A modified suture technique has been developed to withstand physiological loading and off load the artificial construct while integration occurs. Lapine tendons were used ex vivo to test the strength of different suture techniques with different sizes of Prolene sutures and tissue-engineered collagen constructs in situ. The data were compared to standard modified Kessler suture using a standard tendon graft. Mechanical testing was carried out and a finite element analysis stress distribution model constructed using COMSOL 3.5 software. The break point for modified suture technique with a tissue-engineered scaffold was significantly higher (50.62 N) compared to a standard modified Kessler suture (12.49 N, p<0.05). Distributing suture tension further proximally and distally from the tendon ends increased the mechanical strength of the repairs. We now have ex vivo proof of concept that this suture technique is suitable for testing in vivo, and this will be the next stage of our research. PMID:24083088

  16. Modified Weaver-Dunn Procedure Versus The Use of Semitendinosus Autogenous Tendon Graft for Acromioclavicular Joint Reconstruction

    PubMed Central

    Hegazy, Galal; Safwat, Hesham; Seddik, Mahmoud; Al-shal, Ehab A.; Al-Sebai, Ibrahim; Negm, Mohame

    2016-01-01

    Background: The optimal operative method for acromioclavicular joint reconstruction remains controversial. The modified Weaver-Dunn method is one of the most popular methods. Anatomic reconstruction of coracoclavicular ligaments with autogenous tendon grafts, widely used in treating chronic acromioclavicular joint instability, reportedly diminishes pain, eliminates sequelae, and improves function as well as strength. Objective: To compare clinical and radiologic outcomes between a modified Weaver-Dunn procedure and an anatomic coracoclavicular ligaments reconstruction technique using autogenous semitendinosus tendon graft. Methods: Twenty patients (mean age, 39 years) with painful, chronic Rockwood type III acromioclavicular joint dislocations were subjected to surgical reconstruction. In ten patients, a modified Weaver-Dunn procedure was performed, in the other ten patients; autogenous semitendinosus tendon graft was used. The mean time between injury and the index procedure was 18 month (range from 9 – 28). Clinical evaluation was performed using the Oxford Shoulder Score and Nottingham Clavicle Score after a mean follow-up time of 27.8 months. Preoperative and postoperative radiographs were compared. Results: In the Weaver-Dunn group the Oxford Shoulder Score improved from 25±4 to 40±2 points. While the Nottingham Clavicle Score increased from 48±7 to 84±11. In semitendinosus tendon graft group, the Oxford Shoulder Score improved from 25±3 points to 50±2 points and the Nottingham Clavicle Score from 48±8 points to 95±8, respectively. Conclusion: Acromioclavicular joint reconstruction using the semitendinosus tendon graft achieved better Oxford Shoulder Score and Nottingham Clavicle Score compared to the modified Weaver-Dunn procedure. PMID:27347245

  17. Synovial Mesenchymal Stem Cells Promote Meniscus Regeneration Augmented by an Autologous Achilles Tendon Graft in a Rat Partial Meniscus Defect Model

    PubMed Central

    Ozeki, Nobutake; Muneta, Takeshi; Matsuta, Seiya; Koga, Hideyuki; Nakagawa, Yusuke; Mizuno, Mitsuru; Tsuji, Kunikazu; Mabuchi, Yo; Akazawa, Chihiro; Kobayashi, Eiji; Saito, Tomoyuki; Sekiya, Ichiro

    2015-01-01

    Although meniscus defects and degeneration are strongly correlated with the later development of osteoarthritis, the promise of regenerative medicine strategies is to prevent and/or delay the disease's progression. Meniscal reconstruction has been shown in animal models with tendon grafting and transplantation of mesenchymal stem cells (MSCs); however, these procedures have not shown the same efficacy in clinical studies. Here, our aim was to investigate the ability of tendon grafts pretreated with exogenous synovial-derived MSCs to prevent cartilage degeneration in a rat partial meniscus defect model. We removed the anterior half of the medial meniscus and grafted autologous Achilles tendons with or without a 10-minute pretreatment of the tendon with synovial MSCs. The meniscus and surrounding cartilage were evaluated at 2, 4, and 8 weeks (n = 5). Tendon grafts increased meniscus size irrespective of synovial MSCs. Histological scores for regenerated menisci were better in the tendon + MSC group than in the other two groups at 4 and 8 weeks. Both macroscopic and histological scores for articular cartilage were significantly better in the tendon + MSC group at 8 weeks. Implanted synovial MSCs survived around the grafted tendon and native meniscus integration site by cell tracking assays with luciferase+, LacZ+, DiI+, and/or GFP+ synovial MSCs and/or GFP+ tendons. Flow cytometric analysis showed that transplanted synovial MSCs retained their MSC properties at 7 days and host synovial tissue also contained cells with MSC characteristics. Synovial MSCs promoted meniscus regeneration augmented by autologous Achilles tendon grafts and prevented cartilage degeneration in rats. Stem Cells 2015;33:1927–1938 PMID:25993981

  18. Plantar Fat Grafting and Tendon Balancing for the Diabetic Foot Ulcer in Remission

    PubMed Central

    Luu, Cynthia A.; Larson, Ethan; Rankin, Timothy M.; Pappalardo, Jennifer L.; Slepian, Marvin J.

    2016-01-01

    Summary: We report on the use of free fat grafting as a means of redistributing normal and shear stress after healing of plantar diabetic foot wounds. Although fat augmentation (lipofilling) has been described previously as an approach to supplement defects and prevent atrophy, including use as an adjunct to wound healing and to mitigate pain in the foot, we are unaware of any reports in the medical literature that have described its use in the high-risk diabetic foot in remission. An active 37-year-old man with type 2 diabetes and neuropathy presented with gangrene of his fifth ray, which was amputated. He subsequently developed a chronic styloid process ulceration that progressed despite treatment. We performed a tibialis anterior tendon transfer and total contact casting. He went on to heal but with residual fat pad atrophy and recalcitrant preulcerative lesions. We then used autologous fat grafting for the plantar atrophy. The patient was able to successfully transition to normal shoe gear after 4 weeks with successful engraftment without complication or recurrence of the wound at 6 weeks. This therapy may provide a promising adjunct to increase ulcer-free days to the patient in diabetic foot remission. PMID:27536489

  19. Examination and Treatment of Hamstring Related Injuries

    PubMed Central

    2012-01-01

    Context: There is a wide spectrum of hamstring-related injuries that can occur in the athlete. Accurate diagnosis is imperative to prevent delayed return to sport, injury recurrence, and accurate clinical decision making regarding the most efficacious treatment. Evidence Acquisition: This review highlights current evidence related to the diagnosis and treatment of hamstring-related injuries in athletes. Data sources were limited to peer-reviewed publications indexed in MEDLINE from 1988 through May 2011. Results: An accurate diagnostic process for athletes with posterior thigh–related complaints should include a detailed and discriminative history, followed by a thorough clinical examination. Diagnostic imaging should be utilized when considering hamstring avulsion or ischial apophyseal avulsion. Diagnostic imaging may also be needed to further define the cause of referred posterior thigh pain. Conclusions: Differentiating acute hamstring strains, hamstring tendon avulsions, ischial apophyseal avulsions, proximal hamstring tendinopathies, and referred posterior thigh pain is critical in determining the most appropriate treatment and expediting safe return to play. PMID:23016076

  20. Differences in Tendon Graft Healing Between the Intra-articular and Extra-articular Ends of a Bone Tunnel

    PubMed Central

    Bedi, Asheesh; Kawamura, Sumito; Ying, Liang

    2008-01-01

    The basic biology of healing between a tendon graft and bone tunnel remains incompletely understood. Distinct variability in the morphological characteristics of the healing tendon–bone attachment site has been reported. We hypothesized that spatial and temporal differences in tendon-to-bone healing exist at different regions of a surgically created bone tunnel. Twenty-four male, Sprague–Dawley rats underwent anterior cruciate ligament (ACL) reconstruction in the left knee using a flexor digitorum longus tendon graft secured using suspensory periosteal fixation. Animals were sacrificed at 4, 7, 11, 14, 21, and 28 days after surgery and prepared for routine histology and immunohistochemical analysis of the healing enthesis at the intra-articular aperture (IAA), mid-tunnel, and extra-articular aperture (EAA). Six animals were used to measure mineral apposition rate (MAR) along the healing bone tunnel by double fluorochrome labeling at 14 and 28 days after surgery. The total area of calcified bone matrix was assessed with von Kossa staining and Goldner-Masson trichrome staining, respectively. The healing tendon–bone interface tissue exhibited a wide chondroid matrix at the IAA, in contrast to a narrow, fibrous matrix at the EAA. There were significantly more osteoclasts at the IAA compared to EAA throughout the study period, except 4 days after surgery (p < 0.05). Collagen continuity between the tendon graft and bone tunnel increased over time, with a more parallel orientation and increased collagen fiber continuity between tendon and bone at the EAA compared to the IAA. MAR was also significantly greater at the EAA at 4 weeks (p < 0.001). Significant differences in healing between the tendon graft and bone exist along the length of bone tunnel secured with suspensory fixation. The etiology of these differences is likely multifactorial in nature, including variable biological and biomechanical environments at different ends of the tunnel

  1. Anterior cruciate ligament reconstruction graft harvesting: pitfalls and tips.

    PubMed

    McGuire, David A; Hendricks, Stephen D

    2007-12-01

    Surgical treatment for anterior cruciate ligament deficiency has relied predominantly on reconstruction with autografts. Grafts taken from patients' own central third of their patellar tendon, bone-patellar tendon bone, or one or more of the hamstring tendons, semitendinosus, and gracilis, constitute the majority of grafts used for these purposes. Although there is no single graft option that clearly outperforms another, an abundance of articles replete with complications associated with harvest and use are available from peer-reviewed journals. It is these complications and their prevention that will be addressed in the following chapter. The idea in mind is that the reader might adopt these techniques to improve their patient outcomes by minimizing, or eliminating, the ongoing problems that such complications produce. PMID:18004217

  2. Direct Lentiviral-Cyclooxygenase 2 Application to the Tendon-Bone Interface Promotes Osteointegration and Enhances Return of the Pull-Out Tensile Strength of the Tendon Graft in a Rat Model of Biceps Tenodesis

    PubMed Central

    Wergedal, Jon E.; Stiffel, Virginia; Lau, Kin-Hing William

    2014-01-01

    This study sought to determine if direct application of the lentiviral (LV)-cyclooxygenase 2 (COX2) vector to the tendon-bone interface would promote osteointegration of the tendon graft in a rat model of biceps tenodesis. The LV-COX2 gene transfer strategy was chosen for investigation because a similar COX2 gene transfer strategy promoted bony bridging of the fracture gap during bone repair, which involves similar histologic transitions that occur in osteointegration. Briefly, a 1.14-mm diameter tunnel was drilled in the mid-groove of the humerus of adult Fischer 344 rats. The LV-COX2 or βgal control vector was applied directly into the bone tunnel and onto the end of the tendon graft, which was then pulled into the bone tunnel. A poly-L-lactide pin was press-fitted into the tunnel as interference fixation. Animals were sacrificed at 3, 5, or 8 weeks for histology analysis of osteointegration. The LV-COX2 gene transfer strategy enhanced neo-chondrogenesis at the tendon-bone interface but with only marginal effect on de novo bone formation. The tendon-bone interface of the LV-COX2-treated tenodesis showed the well-defined tendon-to-fibrocartilage-to-bone histologic transitions that are indicative of osteointegration of the tendon graft. The LV-COX2 in vivo gene transfer strategy also significantly enhanced angiogenesis at the tendon-bone interface. To determine if the increased osteointegration was translated into an improved pull-out mechanical strength property, the pull-out tensile strength of the LV-COX2-treated tendon grafts was determined with a pull-out mechanical testing assay. The LV-COX2 strategy yielded a significant improvement in the return of the pull-out strength of the tendon graft after 8 weeks. In conclusion, the COX2-based in vivo gene transfer strategy enhanced angiogenesis, osteointegration and improved return of the pull-out strength of the tendon graft. Thus, this strategy has great potential to be developed into an effective therapy to

  3. Direct lentiviral-cyclooxygenase 2 application to the tendon-bone interface promotes osteointegration and enhances return of the pull-out tensile strength of the tendon graft in a rat model of biceps tenodesis.

    PubMed

    Rundle, Charles H; Chen, Shin-Tai; Coen, Michael J; Wergedal, Jon E; Stiffel, Virginia; Lau, Kin-Hing William

    2014-01-01

    This study sought to determine if direct application of the lentiviral (LV)-cyclooxygenase 2 (COX2) vector to the tendon-bone interface would promote osteointegration of the tendon graft in a rat model of biceps tenodesis. The LV-COX2 gene transfer strategy was chosen for investigation because a similar COX2 gene transfer strategy promoted bony bridging of the fracture gap during bone repair, which involves similar histologic transitions that occur in osteointegration. Briefly, a 1.14-mm diameter tunnel was drilled in the mid-groove of the humerus of adult Fischer 344 rats. The LV-COX2 or βgal control vector was applied directly into the bone tunnel and onto the end of the tendon graft, which was then pulled into the bone tunnel. A poly-L-lactide pin was press-fitted into the tunnel as interference fixation. Animals were sacrificed at 3, 5, or 8 weeks for histology analysis of osteointegration. The LV-COX2 gene transfer strategy enhanced neo-chondrogenesis at the tendon-bone interface but with only marginal effect on de novo bone formation. The tendon-bone interface of the LV-COX2-treated tenodesis showed the well-defined tendon-to-fibrocartilage-to-bone histologic transitions that are indicative of osteointegration of the tendon graft. The LV-COX2 in vivo gene transfer strategy also significantly enhanced angiogenesis at the tendon-bone interface. To determine if the increased osteointegration was translated into an improved pull-out mechanical strength property, the pull-out tensile strength of the LV-COX2-treated tendon grafts was determined with a pull-out mechanical testing assay. The LV-COX2 strategy yielded a significant improvement in the return of the pull-out strength of the tendon graft after 8 weeks. In conclusion, the COX2-based in vivo gene transfer strategy enhanced angiogenesis, osteointegration and improved return of the pull-out strength of the tendon graft. Thus, this strategy has great potential to be developed into an effective therapy to

  4. COMPARISON BETWEEN THE RESULTS ACHIEVED IN ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION WITH TWO KINDS OF AUTOLOGOUS GRAFTS: PATELLAR TENDON VERSUS SEMITENDINOUS AND GRACILIS

    PubMed Central

    Abdalla, Rene Jorge; Monteiro, Diego Antico; Dias, Leonardo; Correia, Dárcio Maurício; Cohen, Moisés; Forgas, Andrea

    2015-01-01

    Objective: this study aims to compare the arthrometric and isokinetic examination results from two types of autologous grafts: the central third of the patellar ligament and a graft formed by the tendons of the semitendinosus and gracilis muscles, within the same rehabilitation protocol, six months after the surgery. Methods: the results from examinations carried out on 63 patients were analyzed. These patients were divided in two groups: one group of 30 patients who received a patellar tendon graft and another group of 33 patients who received a graft from the tendons of the semitendinosus and gracilis muscles. Both the grafts were attached in the same way, with Endobutton™ for suspensory fixation to the femur and a bioabsorbable interference screw for fixation in the tibial tunnel. Results: arthrometry 30 did not present any statistical difference between the two study groups. On the other hand, the isokinetic evaluation showed that the patellar tendon group had a larger mean peak torque of flexion and greater extension deficit, while the semitendinosus/gracilis group had a better mean flexion/extension ratio and greater percentage of flexion deficit. There was no statistically significant difference between the groups when measuring peak torque extension. Conclusion: therefore, when the patellar tendon was used, there was greater extensor deficit and, when the semitendinosus/gracilis tendons were used, there was greater flexor deficit. PMID:27004173

  5. Reconstruction of Chronic Foveal TFCC Tears with an Autologous Tendon Graft

    PubMed Central

    Bain, Gregory I.; Eng, Kevin; Lee, Yu Chao; Mcguire, Duncan; Zumstein, Matthias

    2015-01-01

    Background A triangular fibrocartilage complex (TFCC) injury can produce distal radioulnar joint (DRUJ) instability. If the foveal attachment is avulsed, it translates distally. The footprint is separated from its origin and will become covered in synovitis, preventing healing. The authors describe a surgical technique for the treatment of instability of the DRUJ due to chronic foveal detachment of the TFCC. Technique The procedure utilizes a loop of autologous palmaris longus tendon graft passed through the ulnar aspect of the TFCC and through an osseous tunnel in the distal ulna to reconstruct the fovel attachment. Patients and Methods We report on nine patients with a mean age of 42. Median follow-up was 13 months. Results The median pain scores measured were reduced from 8 to 3 postoperatively, and all had a stable DRUJ. Conclusions This technique provides stability of the distal ulna to the radius and carpus, with potential for biologic healing through osseous integration. It is a robust, anatomically based reconstruction of the TFCC to the fovea that stabilizes the DRUJ and the ulnar-carpal sag. PMID:25709873

  6. Hamstring injuries: anatomy, imaging, and intervention.

    PubMed

    Linklater, James M; Hamilton, Bruce; Carmichael, James; Orchard, John; Wood, David G

    2010-06-01

    Injury to the hamstring muscle complex (HMC) is extremely common in the athletic community. Anatomical and functional aspects of the HMC predispose it to injury, including the fact that the muscles cross two joints and undergo eccentric contraction during the gait cycle. Injury most commonly occurs at the muscle tendon junction but may occur anywhere between the origin and insertion. Complete hamstring avulsions require early surgical repair. The principal indication for imaging is in a triage role to rule out or confirm proximal hamstring avulsion. Acute onset and chronic posterior thigh and buttock pain may relate to pathology at the hamstring origin or muscle tendon junction that can be readily defined on magnetic resonance imaging or, less frequently, ultrasound. Some cases of buttock and thigh pain may relate to spinal pathology. In the elite athlete there is an increasing emphasis on optimizing the rehabilitation process after hamstring injury, to minimize the absence from sports and improve the final outcome. Imaging has a role in confirming the site of injury and characterizing its extent, providing some prognostic information and helping plan treatment. There is increasing interest in the use of growth factors to accelerate healing after muscle and tendon injury. Animal studies have demonstrated clear benefits in terms of accelerated healing. There are various methods of delivery of the growth factors, all involving the release of growth factors from platelets. These include plasma rich in platelets and autologous blood. Clinical studies in humans are very limited at this stage but are promising. At present the World Anti-Doping Authority bans the intramuscular administration of these agents. Other percutaneous injection therapies include the use of Actovegin and Traumeel S and antifibrotic agents. PMID:20486024

  7. Structural mechanical properties of radiation-sterilized human Bone-Tendon-Bone grafts preserved by different methods.

    PubMed

    Gut, Grzegorz; Marowska, Joanna; Jastrzebska, Anna; Olender, Ewa; Kamiński, Artur

    2016-06-01

    To avoid the risk of infectious disease transmission from donor to recipient, allografts should be terminally sterilized. In the previous paper (Kaminski et al. in Cell Tissue Bank 10:215-219, 2009) we presented the effect of various methods of preservation (deep fresh freezing, glycerolization, lyophilization), followed by irradiation with different doses of electron beam (EB), on material (intrinsic) mechanical properties of human patellar tendons cut out as for anterior cruciate ligament reconstruction, obtained in failure tensile test. As structural mechanical properties are equally important to predict the behaviour of the graft as a whole functional unit, the purpose of the present paper was to show the results for failure load and elongation, obtained in the same experiment. Paired Bone-Tendon-Bone grafts (BTB) were prepared from cadaveric human patella tendons with both patellar and tibial attachments. They were preserved by deep freezing, glycerolization or lyophilization and subsequently EB-irradiated with the doses of 25, 35, 50 or 100 kGy (fresh-frozen grafts) or a single dose of 35 kGy (glycerolized and lyophilized grafts). Each experimental (irradiated) group was provided with control (non-irradiated), donor-matched group. The specimens from all groups were subjected to mechanical failure tensile test with the use of Instron system in order to measure their structural properties (failure load and elongation). All lyophilized grafts were rehydrated before mechanical testing. In our study we did not observe significant deterioration of structural mechanical properties of BTB grafts processed by fresh-freezing and then terminal sterilized with growing doses of EB up to 100 kGy. In contrast, BTB grafts processed by glycerolization or lyophilization and irradiated with 35 kGy showed significant decrease of failure load. Obtained results suggest that deep-frozen irradiated grafts retain their initial mechanical properties to an extent which does not

  8. Electrophysiological Assessment of Injury to the Infra-patellar Branch(es) of the Saphenous Nerve during Anterior Cruciate Ligament Reconstruction Using Medial Hamstring Auto-grafts: Vertical versus Oblique Harvest Site Incisions

    PubMed Central

    Tavakoli Darestani, Reza; Bagherian Lemraski, Mohammad Mehdi; Hosseinpour, Mehrdad; Kamrani-Rad, Amin

    2013-01-01

    Background It was suggested that the direction of incision for medial hamstring tendons harvesting influences the incidence of injury to the infrapatellar branch of the saphenous nerve (IPBSN), a common complication following arthroscopically-assisted anterior cruciate ligament reconstruction (ACLR). Objectives The main purpose of current study was to compare the incidence of IPBSN injury between vertical and oblique incisions utilizing electrophysiological evaluation. Patients and Methods There were 60 patients underwent arthroscopically-assisted ACLR assigned to two equal vertical or oblique incision groups, randomly. One year postoperatively, the patients were electrophysiologically examined to detect whether IPBSN is injured. The Lysholm score was completed. The patients' satisfaction with surgical outcomes determined utilizing visual analogue scale (VAS). Finally, two groups were compared and the effect of IPBSN injury on function and satisfaction was investigated. Results The incidence of IPBSN injury was higher in the vertical group (4 patients vs. 10 patients), but the difference was not statistically significant. The mean of Lysholm and VAS scores were the same. Also, the mean of Lysholm score was the same in patients with and without IPBSN injury. However, patients without IPBSN injury were more satisfied (8.9 ± 9 vs. 7.4 ± 1.1; P < 0.001). Conclusions IPBSN injury is a common complication following arthroscopically-assisted ACLR and, if not significant, oblique direction of the incision is associated with decreased incidence of the injury. IPBSN injury has no effect on the function but because of the disturbance with patients' satisfaction, authors believe the oblique incision is preferable to avoid the nerve injury during medial hamstring tendons harvesting. PMID:24693521

  9. BIOMECHANICAL STUDY OF TRANSCORTICAL OR TRANSTRABECULAR BONE FIXATION OF PATELLAR TENDON GRAFT WITH BIOABSORBABLE PINS IN ACL RECONSTRUCTION IN SHEEP

    PubMed Central

    Albano, Mauro Batista; Borges, Paulo César; Namba, Mario Massatomo; da Silva, João Luiz Vieira; de Assis Pereira Filho, Francisco; Filho, Edmar Stieven; Matias, Jorge Eduardo Fouto

    2015-01-01

    Objective: To determine the initial resistance of fixation using the Rigid Fix® system, and compare it with traditional fixation methods using metal interference screws; and to evaluate the resistance of the fixation with the rigid fix system when the rotational position of the bone block is altered in the interior of the femoral tunnel. Methods: forty ovine knee specimens (stifle joints) were submitted to anterior cruciate ligament reconstruction (ACL) using a bone-tendon-bone graft. In twenty specimens, the Rigid Fix method was used; this group was subdivided into two groups: ten knees the pins transfixed only the spongious area of the bone block, and ten for fixation passing through the layer of cortical bone. In the twenty remaining specimens, the graft was fixed with 9mm metal interference screws. Results: comparison of the RIGIDFIX® method with the metal interference screw fixation method did not show any statistically significant differences in terms of maximum load and rigidity; also, there were no statistically significant differences when the rotational position of the bone block was altered inside the femoral tunnel. For these evaluations, a level of significance of p < 0.017 was considered. Conclusion: fixation of the bone-tendon-bone graft with 2 bioabsorbable pines, regardless of the rotational position inside the femoral tunnel, gave a comparable fixation in terms of initial resistance to the metal interference screw, in this experimental model. PMID:27027081

  10. Bi-linear mechanical property determination of acellular human patellar tendon grafts for use in anterior cruciate ligament replacement.

    PubMed

    Herbert, Anthony; Brown, Christopher; Rooney, Paul; Kearney, John; Ingham, Eileen; Fisher, John

    2016-06-14

    Anterior cruciate ligament rupture is rising in its prevalence amongst the young and those with physically active lifestyles. Acellular human patellar tendon (PT) grafts offer a promising restoration solution, returning knee joint stability and overcoming some of the current disadvantages of autologous or allogeneic grafts. However, it is necessary to ensure that the decellularisation bio-processes involved do not cause structural changes in the microstructure of the tendon tissue that may adversely affect the mechanical properties, particularly with respect to the physiological range of loading. Sixteen cadaveric human PT grafts were sourced and processed from eight donors, with full ethical approval and consent for use in research. Eight specimens were allocated for decellularisation, while the remaining eight contralateral specimens were used as native controls. Testing consisted of 12 preconditioning cycles followed by uniaxial extension until failure occurred. Stress-strain data was then fitted to a bi-linear model using least squares regression by a custom-written Matlab script. The elastic moduli for the toe region and linear region of each specimen were determined, in addition to the transition point co-ordinates and strain energy density for increasing strain. No significant differences were found between groups for all of the parameters investigated. Hence, the shape and magnitude of the stress-strain profile was found to be the same for both groups throughout loading. The results of this study indicated that decellularisation appeared to have no effect on the material properties of human PT grafts under quasistatic conditions. Therefore, acellular human PT grafts can offer a viable additional solution for ACL replacement compared to current autologous and allogeneic treatment options. PMID:27063250

  11. Anterior cruciate ligament reconstruction best practice: A review of graft choice

    PubMed Central

    Shaerf, Daniel A; Pastides, Philip S; Sarraf, Khaled M; Willis-Owen, Charles A

    2014-01-01

    There is much literature about differing grafts used in anterior cruciate ligament (ACL) reconstruction. Much of this is of poor quality and of a low evidence base. We review and summarise the literature looking at the four main classes of grafts used in ACL reconstruction; bone-patella tendon-bone, hamstrings, allograft and synthetic grafts. Each graft has the evidence for its use reviewed and then compared, where possible, to the others. We conclude that although there is no clear “best” graft, there are clear differences between the differing graft choices. Surgeon’s need to be aware of the evidence behind these differences, in order to have appropriate discussions with their patients, so as to come to an informed choice of graft type to best suit each individual patient and their requirements. PMID:24649411

  12. Failure load of patellar tendon grafts at the femoral side: 10- versus 20-mm-bone blocks.

    PubMed

    Meuffels, Duncan E; Niggebrugge, Marnix J N; Verhaar, Jan A N

    2009-02-01

    The aim of the study was to investigate whether use of short bone blocks is safe in anterior cruciate ligament (ACL) reconstruction. Our hypothesis was that the smaller 10-mm-length bone blocks will fail at lower loads than 20-mm-bone blocks. Ten paired human cadaver knees were randomly assigned to the 10- or 20-mm group (group 1 and 2) and underwent bone-patellar tendon-bone femoral fixation with interference screw. Tensile tests were performed using a tensile testing machine (Instron). Stiffness, failure load and failure mode were recorded. Median stiffness was 72 N/mm (16-103) for 10-mm-bone blocks and 91 N/mm (40-130) for 20-mm-bone blocks. Median failure loads were 402 N (87-546) for 10-mm-long bone block and 456 N (163-636) for 20-mm-bone blocks. There was no statistically significant difference between groups (P = 0.35). All bone-patellar tendon-bone grafts were pulled out of the femoral tunnel with interference screw, due to slippage. We concluded that a 10-mm-long bone block was not significantly weaker than a 20-mm-long bone block. Failure loads of a 10-mm-bone block exceeded loading values at passive and active extension of the knee under normal conditions. Ten millimetre bone blocks offered sufficient fixation strength in ACL reconstruction. PMID:18839146

  13. Hydroxyapatite-doped polycaprolactone nanofiber membrane improves tendon-bone interface healing for anterior cruciate ligament reconstruction.

    PubMed

    Han, Fei; Zhang, Peng; Sun, Yaying; Lin, Chao; Zhao, Peng; Chen, Jiwu

    2015-01-01

    Hamstring tendon autograft is a routine graft for anterior cruciate ligament (ACL) reconstruction. However, ways of improving the healing between the tendon and bone is often overlooked in clinical practice. This issue can be addressed by using a biomimetic scaffold. Herein, a biomimetic nanofiber membrane of polycaprolactone/nanohydroxyapatite/collagen (PCL/nHAp/Col) is fabricated that mimics the composition of native bone tissue for promoting tendon-bone healing. This membrane has good cytocompatibility, allowing for osteoblast cell adhesion and growth and bone formation. As a result, MC3T3 cells reveal a higher mineralization level in PCL/nHAp/Col membrane compared with PCL membrane alone. Further in vivo studies in ACL reconstruction in a rabbit model shows that PCL/nHAp/Col-wrapped tendon may afford superior tissue integration to nonwrapped tendon in the interface between the tendon and host bone as well as improved mechanical strength. This study shows that PCL/nHAp/Col nanofiber membrane wrapping of autologous tendon is effective for improving tendon healing with host bone in ACL reconstruction. PMID:26677323

  14. Hamstring injuries: prevention and treatment—an update

    PubMed Central

    Brukner, Peter

    2015-01-01

    Despite increased knowledge of hamstring muscle injuries, the incidence has not diminished. We now know that not all hamstring injuries are the same and that certain types of injuries require prolonged rehabilitation and return to play. The slow stretch type of injury and injuries involving the central tendon both require longer times to return to play. A number of factors have been proposed as being indicators of time taken to return to play, but the evidence for these is conflicting. Recurrence rates remain high and it is now thought that strength deficits may be an important factor. Strengthening exercise should be performed with the hamstrings in a lengthened position. There is conflicting evidence regarding the efficacy of platelet-rich plasma injection in the treatment of hamstring injuries so at this stage we cannot advise their use. Various tests have been proposed as predictors of hamstring injury and the use of the Nordboard is an interesting addition to the testing process. Prevention of these injuries is the ultimate aim and there is increasing evidence that Nordic hamstring exercises are effective in reducing the incidence. PMID:26105015

  15. Correlation between anthropometric data and length and thickness of the tendons of the semitendinosus and gracilis muscles used for grafts in reconstruction of the anterior cruciate ligament☆

    PubMed Central

    Pereira, Rafael Noschang; Karam, Francisco Consoli; Schwanke, Roberto Luís; Millman, Rubens; Foletto, Zilmar Minetto; Schwanke, Carla Helena Augustin

    2016-01-01

    Objective Preoperative estimation of the length and diameter of the semitendinosus (ST) and gracilis (G) tendons can assist surgeons and allow them to have the opportunity to choose alternative grafts. The aim of this study was to investigate whether anthropometric measurements such as height, weight and body mass index (BMI) or the patient's age and sex have any correlation with the thickness and the length of ST and G tendons. Methods Data were gathered from 64 patients who underwent the surgical procedure of anterior cruciate ligament reconstruction using the tendons of the ST and G muscles as grafts, between June 2012 and August 2013. Variables such as age, sex, weight, height, body mass index (BMI) and length and diameter of the tendons of the ST and G muscles were analyzed. Results There was a positive correlation between the height and total diameter of the quadruple graft (r = 0.254; p = 0.043), total length of the ST tendon (r = 0.450; p < 0.01), diameter of the double ST (r = 0.270; p = 0.031), triple ST (r = 0.347; p = 0.005), length of G tendon (r = 0.249; p = 0.047) and diameter of the double-G (r = 0.258; p = 0.039). However, age (r = -0.015; p = 0.908), weight (r = 0.165; p = 0.193) and body mass index (r = 0.012; p = 0.926) showed no correlation. Conclusion Our results show that age, weight and BMI did not correlate with the diameter and length of the graft, while the height had a positive correlation with the total length of the flexor tendons and the diameter of the graft from the flexors (ST and G). PMID:27069886

  16. Minimally invasive reconstruction of the medial patellofemoral ligament using quadriceps tendon.

    PubMed

    Fink, Christian; Veselko, Matjaz; Herbort, Mirco; Hoser, Christian

    2014-06-01

    Reconstruction of the medial patellofemoral ligament (MPFL) for the treatment of patellar instability has received increased attention over the past few years. Most operative techniques use hamstring grafts fixed with bone tunnels and/or anchors on the patella. Despite good clinical results using these techniques, complications such as implant breakage, patellar fractures through bone tunnels, and loss of knee motion have occurred. We present a minimally invasive technique for MPFL reconstruction using a strip of quadriceps tendon. With the use of specially designed instruments, the graft is harvested through a 3-cm transverse incision at the proximal pole of the patella. The tendon strip is then dissected distally on the patella, left attached, and diverged 90° medially underneath the medial prepatellar tissue. The graft is fixed on the femur in 20° of knee flexion in a bone tunnel with a bioabsorbable interference screw (adults) or a bone anchor (children). We think that this technique presents a valuable alternative to common hamstring techniques for primary MPFL reconstruction in children and adults, as well as for MPFL revision surgery. PMID:25126496

  17. Minimally Invasive Reconstruction of the Medial Patellofemoral Ligament Using Quadriceps Tendon

    PubMed Central

    Fink, Christian; Veselko, Matjaz; Herbort, Mirco; Hoser, Christian

    2014-01-01

    Reconstruction of the medial patellofemoral ligament (MPFL) for the treatment of patellar instability has received increased attention over the past few years. Most operative techniques use hamstring grafts fixed with bone tunnels and/or anchors on the patella. Despite good clinical results using these techniques, complications such as implant breakage, patellar fractures through bone tunnels, and loss of knee motion have occurred. We present a minimally invasive technique for MPFL reconstruction using a strip of quadriceps tendon. With the use of specially designed instruments, the graft is harvested through a 3-cm transverse incision at the proximal pole of the patella. The tendon strip is then dissected distally on the patella, left attached, and diverged 90° medially underneath the medial prepatellar tissue. The graft is fixed on the femur in 20° of knee flexion in a bone tunnel with a bioabsorbable interference screw (adults) or a bone anchor (children). We think that this technique presents a valuable alternative to common hamstring techniques for primary MPFL reconstruction in children and adults, as well as for MPFL revision surgery. PMID:25126496

  18. Anatomical reconstruction of the spring ligament using peroneus longus tendon graft.

    PubMed

    Choi, Kyungjin; Lee, Samuel; Otis, James C; Deland, Jonathan T

    2003-05-01

    Posterior tibial tendon insufficiency is often associated with failure of the spring ligament and flatfoot deformity. Arch correction procedures involving bony realignment, such as lateral column lengthening or joint fusions, can predispose to arthritis. Soft tissue reconstruction may provide a more anatomical correction without these complications. The purpose of this investigation was to compare the ability of three different spring ligament reconstruction procedures to correct flatfoot deformity. A deformity model of 5 degrees - 15 degrees talonavicular abduction was created in 10 cadaver foot-ankle specimens. Three reconstructions utilizing the peroneus longus tendon were evaluated for their ability to correct talonavicular abduction and subtalar eversion under 357 N vertical GRF load. A superomedial/plantar passage of the tendon through the calcaneus and navicular was shown to be more effective than either of the other two approaches, correcting the talonavicular joint from 9.1 degrees +/- 8.1 degrees abducted to 1.0 degree +/- 6.8 degrees adducted, and the subtalar joint from 3.1 degrees +/- 3.3 degrees everted to 0.4 degrees +/- 4.2 degrees inverted. Thus, an anatomical reconstruction of a model of a failed spring ligament was demonstrated to be effective in the correction of a flatfoot deformity produced in cadaver foot-ankle specimens. PMID:12801201

  19. Muscle and intensity based hamstring exercise classification in elite female track and field athletes: implications for exercise selection during rehabilitation

    PubMed Central

    Tsaklis, Panagiotis; Malliaropoulos, Nikos; Mendiguchia, Jurdan; Korakakis, Vasileios; Tsapralis, Kyriakos; Pyne, Debasish; Malliaras, Peter

    2015-01-01

    Background Hamstring injuries are common in many sports, including track and field. Strains occur in different parts of the hamstring muscle but very little is known about whether common hamstring loading exercises specifically load different hamstring components. The purpose of this study was to investigate muscle activation of different components of the hamstring muscle during common hamstring loading exercises. Methods Twenty elite female track and field athletes were recruited into this study, which had a single-sample, repeated-measures design. Each athlete performed ten hamstring loading exercises, and an electromyogram (EMG) was recorded from the biceps femoris and semitendinosus components of the hamstring. Hamstring EMG during maximal voluntary isometric contraction (MVIC) was used to normalize the mean data across ten repetitions of each exercise. An electrogoniometer synchronized to the EMG was used to determine whether peak EMG activity occurred during muscle-tendon unit lengthening, shortening, or no change in length. Mean EMG values were compared between the two recording sites for each exercise using the Student’s t-test. Results The lunge, dead lift, and kettle swings were low intensity (<50% MVIC) and all showed higher EMG activity for semitendinosus than for biceps femoris. Bridge was low but approaching medium intensity, and the TRX, hamstring bridge, and hamstring curl were all medium intensity exercises (≥50% or <80% MVIC). The Nordic, fitball, and slide leg exercises were all high intensity exercises. Only the fitball exercise showed higher EMG activity in the biceps femoris compared with the semitendinosus. Only lunge and kettle swings showed peak EMG in the muscle-tendon unit lengthening phase and both these exercises involved faster speed. Conclusion Some exercises selectively activated the lateral and medial distal hamstrings. Low, medium, and high intensity exercises were demonstrated. This information enables the clinician, strength

  20. Distal biceps tendon injuries--current treatment options.

    PubMed

    Quach, Tony; Jazayeri, Reza; Sherman, Orrin H; Rosen, Jeffrey E

    2010-01-01

    Three percent of all biceps tendon ruptures occur at the distal aspect, where the tendon inserts into the radial tuberosity. Distal bicep tendon ruptures typically occur in middle-aged males after an eccentric extension load is applied to the elbow. Patients usually complain of a sudden, sharp, and painful tearing sensation in the antecubital region, with a palpable defect. The biceps squeeze and hook tests are specific maneuvers by which to diagnose distal biceps ruptures on physical examination. Magnetic resonance imaging (MRI) or ultrasound maybe be helpful to distinguish between partial and complete tears. Anatomic studies suggest there are two distinct insertions for the short and long heads of the distal biceps. The short head may be a more powerful flexor, and the long head may be a more powerful supinator. Nonoperative treatment typically results in loss of flexion and supination strength and endurance. Early anatomic re-attachment is the goal. Surgical approaches include one- or two-incision techniques, and tendon fixation methods include the use of suture anchors, bone tunnels, an endobutton, or biotenodesis screws. Biomechanical studies have shown that endobuttons have higher load-to-failure strengths, compared to the other fixation methods. However, clinical studies have demonstrated that patients do well regardless of surgical approach or fixation method. Possible complications include nerve injuries, heterotopic ossification, postoperative fracture, tendon rerupture, complex regional pain syndrome, and wound infection. Partial ruptures are significantly less common and initially can be treated conservatively. Chronic tears are more difficult to treat because of possible tendon retraction and poor tissue quality. Tendon grafts using semitendinosus, fascia lata, hamstring, Achilles (calcaneal), or flexor carpi radialis have been successfully used for length restoration in these cases. PMID:20632985

  1. Bilateral ACL Reconstructions with Hamstring Autografts.

    PubMed

    Panigrahi, Ranajit; Mahapatra, Amita Kumari; Priyadarshi, Ashok; Palo, Nishit; Biswal, Manas R

    2016-07-01

    Bilateral anterior cruciate ligament (ACL) injuries are rare with incidence between 2 and 4%, and presently no definitive guidelines for proper management exist. Ideal treatment protocol remains controversial between a single-stage and two-stage bilateral ACL reconstruction. The purpose of this study is to evaluate the outcome of single-stage bilateral ACL reconstruction with hamstring tendon autografts in bilateral ACL injuries. A prospective study was undertaken including a total of 14 consecutive patients with bilateral ACL deficient knee who underwent single-stage bilateral ACL reconstruction with hamstring tendon autograft with a mean follow-up duration of 28 months (24-38 months). Functional outcomes were evaluated by range of movements, International Knee Documentation Committee (IKDC), Lysholm and Tegner activity score, and stability tests. The mean age was 30 years (range 18-42 years). Average duration of rehabilitation was 8 weeks. Time to return to full-time work and full sports was 5.6 weeks and 6.2 months, respectively. Clinical examination demonstrated full range of motion; a total of 12 patients (86%) had a negative Lachman test and 13 patients (93%) had a negative pivot shift at the final follow-ups. The mean IKDC evaluation score was 89 points, the mean Tegner activity score was 7 points, and the mean Lysholm knee score was 91 points. A total of 12 patients (86%) returned to their preinjury level of activity and an overall greater than 90% satisfaction rate was achieved. Single-stage bilateral ACL reconstruction using hamstring autografts is clinically safe, effective, and cost-effective with better patient compliance and with comparable functional outcome as opposed to two-stage ACL reconstructions. PMID:26408992

  2. Reconstruction of the medial patellofemoral ligament using autologous graft from quadriceps tendon to treat recurrent patellar dislocation☆

    PubMed Central

    Calapodopulos, Constantino Jorge; Nogueira, Marcelo Corvino; Eustáquio, José Martins Juliano; Calapodopulos Júnior, Constantino Jorge; Rodrigues, Oreston Alves

    2016-01-01

    Objective The objective of this study was to evaluate the efficacy of the surgical technique using the quadriceps tendon as a graft in static reconstruction of the medial patellofemoral ligament. Methods This was a prospective case series study in which the participants were 22 patients with a diagnosis of recurrent patellar dislocation without any other anatomical alterations that required surgical treatment. The functional results from the technique were evaluated using clinical data and the Lysholm questionnaire, one year after the operation. Results It was observed that the patients were predominantly female (86%) and under 21 years of age (73%), just like in the literature. At the first annual return after the surgery, there was no significant pain on medium efforts, no loss of range of motion and a positive apprehension test. According to the questionnaire used, the results were graded as good. The patients who reported having severe pain on greater effort were involved in employment-related legal disputes. Conclusion This technique showed low morbidity and good functional results over the short term. PMID:27069888

  3. Treatment of Rockwood type III acromioclavicular joint dislocation using autogenous semitendinosus tendon graft and endobutton technique

    PubMed Central

    Ye, Gang; Peng, Chao-An; Sun, Hua-Bin; Xiao, Jing; Zhu, Kang

    2016-01-01

    Background The aim of this study was to evaluate the therapeutic effect of autogenous semitendinosus graft and endobutton technique, and compare with hook plate in treatment of Rockwood type III acromioclavicular (AC) joint dislocation. Methods From April 2012 to April 2013, we treated 46 patients with Rockwood type III AC joint dislocation. Patients were randomly divided into two groups: Group A was treated using a hook plate and Group B with autogenous semitendinosus graft and endobutton technique. All participants were followed up for 12 months. Radiographic examinations were performed every 2 months postoperatively, and clinical evaluation was performed using the Constant–Murley score at the last follow-up. Results Results indicated that patients in Group B showed higher mean scores (90.3±5.4) than Group A (80.4±11.5) in terms of Constant–Murley score (P=0.001). Group B patients scored higher in terms of pain (P=0.002), activities (P=0.02), range of motion (P<0.001), and strength (P=0.004). In Group A, moderate pain was reported by 2 (8.7%) and mild pain by 8 (34.8%) patients. Mild pain was reported by 1 (4.3%) patient in Group B. All patients in Group B maintained complete reduction, while 2 (8.7%) patients in Group A experienced partial reduction loss. Two patients (8.7%) encountered acromial osteolysis on latest radiographs, with moderate shoulder pain and limited range of motion. Conclusion Autogenous semitendinosus graft and endobutton technique showed better results compared with the hook plate method and exhibited advantages of fewer complications such as permanent pain and acromial osteolysis. PMID:26811685

  4. Electromechanical delay of the knee extensor muscles is not altered after harvesting the patellar tendon as a graft for ACL reconstruction: implications for sports performance.

    PubMed

    Georgoulis, A D; Ristanis, S; Papadonikolakis, A; Tsepis, E; Moebius, U; Moraiti, C; Stergiou, N

    2005-09-01

    Although the scar tissue, which heals the donor site defect, has different elasticity from the neighbouring patellar tissue, it remains unclear if this scar tissue can lead to the changes of the electromechanical delay (EMD) of the knee extensor muscles. If such changes do exist, they can possibly affect both the utilization of the stored energy in the series elastic component, as well as the optimal performance of the knee joint movement. The purpose of this study was to investigate the influence of harvesting the patellar tendon during anterior cruciate ligament (ACL) reconstruction and the associated patellar tendon scar tissue development on the EMD of the rectus femoris (RF) and vastus medialis (VM) muscles. Seventeen patients who underwent an ACL reconstruction using the medial third of the patellar tendon were divided in two groups based upon their post-operative time interval. Maximal voluntary contraction from the knee extensors, surface EMG activity, and ultrasonographic measurements of the patellar tendon cross-section area were obtained from both knees. Our results revealed that no significant changes for the maximal voluntary contraction of the knee extensors and for the EMD of the RF and the VM muscles due to patellar scar tissue development after harvesting the tendon for ACL reconstruction. The EMD, as a component of the stretch reflex, is important for the utilization of the stored energy in the series elastic component and thus, optimal sports performance. However, from our results, it can be implied that the ACL reconstruction using a patellar tendon graft would not impair sports performance as far as EMD is concerned. PMID:15968530

  5. NERVE ENDINGS AND VASCULAR SUPPLY IN SEMITENDINOSUS TENDON OF CEREBRAL PALSY CHILDREN

    PubMed Central

    Grzegorzewski, Andrzej; Synder, Marek; Modrzewski, Tadeusz; Drobniewski, Marek; Polguj, Michał; Sibiński, Marcin

    2015-01-01

    ABSTRACT Objective: To evaluate the distribution of SP (substance P) and S-100 peptide immunoreactivity, as well as the vascular supply of tissues commonly used as grafts for anterior cruciate ligament (ACL) reconstruction. A second aim was to compare the above mentioned distribution in the semitendinosus muscle tendons of cerebral palsy (CP) patients with the semitendinosus muscle tendons and patellar tendons of patients without CP. Methods: The first group consisted of 14 children with cerebral palsy with a mean age of 11.7 years old. At the time of hamstring lengthening operation, a sample of semitendinosus muscle was taken for analysis. The second group comprised 20 patients treated for isolated ACL rupture of the knee (mean age 32 years old). Group three comprised ten patients in the mean age of 14.3 years old treated for recurrent lateral patellar dislocation, and from whom a sample of patellar tendon was obtained. Results: No statistically significant differences were demonstrated with regard to the amount of immunopositive nerve fibers expressing SP or S-100 in all 3 groups of patients. A significant difference was noted in the number of blood vessels between the adult and child semitendinosus muscles, but not between the semitendinosus muscles and patellar tendon of children. Conclusion: The number of nociceptors as well as proprioceptive fibers is similar in patients with CP and patients from a neurologically healthy population. Level of Evidence IV, Cases Series. PMID:26981034

  6. Dose-dependent variations in blood flow evaluation of canine nerve, nerve graft, tendon, and ligament tissue by the radiolabeled-microsphere technique

    SciTech Connect

    Riggi, K.; Wood, M.B.; Ilstrup, D.M. )

    1990-11-01

    This study evaluates the dose-dependent accuracy of the radionuclide-labeled microsphere technique for blood flow evaluation in nerve, tendon, and ligament. In eight dogs, blood flows were determined for nerve, nerve graft, tendon, and ligament tissue by simultaneous injection of high- and low-dose microspheres with different radiolabels. The results demonstrated no significant differences in blood flow as measured from the small number of microspheres (less than 400) and the high number (more than 400) for nerve and tendon tissue. For nerve tissue, microsphere counts of 50 to 100, 100 to 200, 200 to 300, and more than 300 produced mean percentage errors of 12.74% (n = 5, SEM = 4.52), 5.45% (n = 13, SEM = 1.22), 10.22% (n = 6, SEM = 4.37), and 17.08% (n = 12, SEM = 3.30), respectively. For tendon tissue, the same microsphere subdivisions had mean percentage errors of 7.47% (n = 4, SEM = 2.66), 3.63% (n = 6, SEM = 1.34), 15.54% (n = 4, SEM = 4.43), and 12.91% (n = 1), respectively. For ligament tissue, percentage errors were consistently higher; microsphere counts of 30 to 100, 100 to 200, and 200 to 300 produced mean errors of 20.14% (n = 4, SEM = 6.38), 18.66% (n = 4, SEM = 6.24), and 25.78% (n = 2, SEM = 1.97), respectively. Although there was no direct relationship between percentage error and number of microspheres retrieved, we suggest that microsphere counts in the range of 100 to 200 should be considered acceptable for nerve and tendon in the canine. Ligament tissue seems to be less well suited to the microsphere technique; however, further study is warranted.

  7. Effect of curing time and concentration for a chemical treatment that improves surface gliding for extrasynovial tendon grafts in vitro

    PubMed Central

    Tanaka, Toshikazu; Sun, Yu-Long; Zhao, Chunfeng; Zobitz, Mark E.; An, Kai-Nan; Amadio, Peter C.

    2013-01-01

    The purpose of this study was to evaluate whether treatment time and concentration of these reagents have an effect on the resulting gliding resistance. Forty peroneus longus (PL) tendons were used, from 20 adult mongrel dogs, along with the A2 pulley obtained from the ipsilateral hind paw. After the baseline gliding resistance was measured, the PL tendons were treated with one of three concentrations of hyaluronic acid (HA) and 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride (EDC) or N-hydroxysuccinimide (NHS) mixed with 10% gelatin for various times (5, 30, and 60 min). Tendon friction was measured over 1000 cycles of simulated flexion/extension motion. Gliding resistance of the untreated PL tendons had no significant difference among the groups. After surface treatment with low concentration of HA and EDC/NHS for 5-min cure, the gliding resistance was similar to that of the untreated PL tendon and significantly higher than its 30- and 60-min treatment. For the rest of high concentration of HA and EDC/NHS groups, the gliding resistance was lower than that of untreated PL tendon. However, there was no significant difference among the timing points. It is possible to optimize the effect of surface treatment on friction and durability by regulating cure time and concentration of reagents in a canine extrasynovial tendon in vitro. PMID:16752399

  8. [The ACL tear from the pre-operative analysis to a 2-year follow-up, influence of the graft choice on the subjective and objective evaluation].

    PubMed

    Dejour, D; Potel, J-F; Gaudot, F; Panisset, J-C; Condouret, J

    2008-12-01

    This study is a synthesis of three series. The first study was prospective on 418 patients with an anterior cruciate ligament (ACL) tear (group I). Two population of ACL ruptures were identified. One population with a postero-lateral bundle preserved in 16%, the mean medial anterior tibial translation side to side was 4.97 mm, the Lachman test was delayed in 40% with no or glide pivot shift in 73%. The second population with a complete ACL tear had a mean medial anterior tibial translation side to side of 7.93 mm, the Lachman test was soft in 98% with gross pivot shift in 80%. The second study was a retrospective study on 258 patients (group II) at 26 months follow-up, it correlated the impact of the type of graft on the clinical objective and subjective results. Twenty-eight percent had anterior knee pain, 33% for the patellar tendon and 25% for the hamstrings, the subjective IKDC was significantly lower for the painful knees, and 68% of the patellar tendon had a hypoesthesia and only 32% for the hamstrings. The ability to walk on the knee was 68% for the hamstrings and 35% for the patellar tendon. The third study was retrospective on 127 patients, 24 months after ACL reconstruction (group III), all were tested on a isokinetic machine for the extensor, the flexor and the internal rotator. In the total population, a 10% extensor and flexor deficit and a 5% rotator deficit was noted. A significant difference between patellar tendon and hamstrings in terms of muscular recovery was found. It pointed out that a more specific rehabilitation should be done on the hamstring group. The muscular recovery was correlated to the highest subjective score. This study allowed the surgeon to be more specific in the ACL tear definition, to adapt the graft choice to the type of sport activity but also to the type of work the patient does and finally to modify the rehabilitation protocol for the hamstring technique. PMID:19046692

  9. Preparation and characterization of antiadhesion barrier film from hyaluronic acid-grafted electrospun poly(caprolactone) nanofibrous membranes for prevention of flexor tendon postoperative peritendinous adhesion

    PubMed Central

    Chen, Shih-Hsien; Chen, Chih-Hao; Shalumon, K T; Chen, Jyh-Ping

    2014-01-01

    Peritendinous adhesion is one of the common complications encountered after tendon injury and subsequent surgery, and it can be minimized by introducing a physical barrier between the injured site and the surrounding tissue. An electrospun hyaluronic acid-grafted poly(caprolactone) (PCL-g-HA) nanofibrous membrane (NFM) is proposed as an alternative to current antiadhesion barrier films. HA is covalently grafted to surface-aminolyzed PCL nanofibers, using carbodiimide as the coupling agent. Pristine PCL and PCL-g-HA NFMs were characterized by scanning electron microscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, and mechanical testing. In vitro cell culture with fibroblasts showed that PCL-g-HA NFMs reduced cellular adhesion on the membrane surface while maintaining cell proliferation. Animal experiments using a rabbit flexor digitorum profundus tendon model confirmed the efficacy of PCL-g-HA in reducing peritendinous adhesion, based on gross observation, histology, joint flexion-angle measurements, gliding tests, and biomechanical evaluation. PMID:25187711

  10. Biceps femoris tendon injuries sustained while playing hockey

    PubMed Central

    Watura, Christopher; Harries, William

    2011-01-01

    A 42-year-old female nurse presented in March 2008 with a left proximal hamstring tendon injury sustained while playing hockey. At surgery, the proximal biceps femoris tendon and semitendonosus were found to be ruptured and were repaired. The patient made a good recovery but sustained a further hockey injury in January 2010 involving a complete tear and rupture of the biceps femoris tendon distally. This was managed conservatively and the patient was able to return to playing hockey 10 months later. Biceps femoris tendon injuries have been reported in sport but this is the first documented case of the injury occurring while playing hockey and is also the first reported case of a biceps tendon rupture proximally (hamstring tendon) followed by distal biceps femoris rupture at the knee in the same leg. PMID:22715185

  11. Elastography Study of Hamstring Behaviors during Passive Stretching

    PubMed Central

    Le Sant, Guillaume; Ates, Filiz; Brasseur, Jean-Louis; Nordez, Antoine

    2015-01-01

    Introduction The mechanical properties of hamstring muscles are usually inferred from global passive torque/angle relationships, in combination with adjoining tissues crossing the joint investigated. Shear modulus measurement provides an estimate of changes in muscle-tendon stiffness and passive tension. This study aimed to assess the passive individual behavior of each hamstring muscle in different stretching positions using shear wave elastography. Methods/Results The muscle shear modulus of each hamstring muscle was measured during a standardized slow passive knee extension (PKE, 80% of maximal range of motion) on eighteen healthy male volunteers. Firstly, we assessed the reliability of the measurements. Results were good for semitendinosus (ST, CV: 8.9%-13.4%), semimembranosus (SM, CV: 10.3%-11.2%) and biceps femoris long-head (BF-lh, CV: 8.6%-13.3%), but not for biceps femoris short-head (BF-sh, CV: 20.3%-44.9%). Secondly, we investigated each reliable muscle in three stretch positions: 70°, 90° and 110° of hip flexion. The results showed different values of shear modulus for the same amount of perceived stretch, with the highest measurements in the high-flexed hip situation. Moreover, individual muscles displayed different values, with values increasing or BF-lh, SM and ST, respectively. The inter-subject variability was 35.3% for ST, 27.4% for SM and 30.2% for BF-lh. Conclusion This study showed that the hip needs to be high-flexed to efficiently tension the hamstrings, and reports a higher muscle-tendon stress tolerance at 110° of hip angle. In addition muscles have different passive behaviors, and future works will clarify if it can be linked with rate of injury. PMID:26418862

  12. Effects of Prior Hamstring Strain Injury on Strength, Flexibility, and Running Mechanics

    PubMed Central

    Silder, Amy; Thelen, Darryl G.; Heiderscheit, Bryan C.

    2010-01-01

    Background Previous studies have shown evidence of residual scar tissue at the musculotendon junction following an acute hamstring strain injury, which could influence re-injury risk. The purpose of this study was to investigate whether bilateral differences in strength, neuromuscular patterns, and musculotendon kinematics during sprinting are present in individuals with a history of unilateral hamstring injury, and whether such differences are linked to the presence of scar tissue. Methods Eighteen subjects with a previous hamstring injury (>5 months prior) participated in a magnetic resonance (MR) imaging exam, isokinetic strength testing, and a biomechanical assessment of treadmill sprinting. Bilateral comparisons were made for peak knee flexion torque, angle of peak torque, and hamstrings:quadriceps strength ratio during strength testing, and muscle activations and peak hamstring stretch during sprinting. MR images were used to measure the volumes of the proximal tendon/aponeurois of the biceps femoris, with asymmetries considered indicative of residual scar tissue. Findings A significantly enlarged proximal biceps femoris tendon volume was measured on the side of prior injury. However, no significant differences between the previously injured and uninjured limbs were found in strength measures, peak hamstring stretch, or muscle activation patterns. Further, the degree of asymmetry in tendon volume was not correlated to any of the functional measures. Interpretation The results of this study indicate that injury-induced changes in morphology do not seem discernable from strength measures, running kinematics, or muscle activity patterns. Further research is warranted to ascertain whether residual scarring alters localized musculotendon tissue mechanics in a way that may contribute to the high rates of muscle re-injury that are observed clinically. PMID:20621753

  13. PLA-grafting of collagen chains leading to a biomaterial with mechanical performances useful in tendon regeneration.

    PubMed

    Bellini, Davide; Cencetti, Claudia; Sacchetta, Anna Cristina; Battista, Angela Maria; Martinelli, Andrea; Mazzucco, Laura; Scotto D'Abusco, Anna; Matricardi, Pietro

    2016-12-01

    With the aim to obtain a scaffold with improved mechanical properties with respect to collagen for tendon augmentation and regeneration, a novel collagen-based material was prepared via heterogeneous phase derivatization of type I collagen sponges using polylactic acid. Compared to the untreated collagen, the functionalized sponge (Coll-PLA) was characterized by higher tensile properties and lower swelling capability; the degradation rate of Coll-PLA, in the presence of collagenase, was lower than that of the untreated collagen sponge. These results are related to an increased hydrophobic character of the collagen matrix due to the presence of PLA chains. In vitro tests, performed with human primary fibroblasts, showed that cell adhesion and proliferation rate on Coll-PLA were comparable to those obtained with the non-functionalized collagen. These findings suggest that the new biomaterial could be suitable as scaffold in tendon augmentation and regeneration. PMID:27498425

  14. Runx2-Modified Adipose-Derived Stem Cells Promote Tendon Graft Integration in Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Zhang, Xin; Ma, Yong; Fu, Xin; Liu, Qiang; Shao, Zhenxing; Dai, Linghui; Pi, Yanbin; Hu, Xiaoqing; Zhang, Jiying; Duan, Xiaoning; Chen, Wenqing; Chen, Ping; Zhou, Chunyan; Ao, Yingfang

    2016-01-01

    Runx2 is a powerful osteo-inductive factor and adipose-derived stem cells (ADSCs) are multipotent. However, it is unknown whether Runx2-overexpressing ADSCs (Runx2-ADSCs) could promote anterior cruciate ligament (ACL) reconstruction. We evaluated the effect of Runx2-ADSCs on ACL reconstruction in vitro and in vivo. mRNA expressions of osteocalcin (OCN), bone sialoprotein (BSP) and collagen I (COLI) increased over time in Runx2-ADSCs. Runx2 overexpression inhibited LPL and PPARγ mRNA expressions. Runx2 induced alkaline phosphatase activity markedly. In nude mice injected with Runx2-ADSCs, promoted bone formation was detected by X-rays 8 weeks after injection. The healing of tendon-to-bone in a rabbit model of ACL reconstruction treated with Runx2-ADSCs, fibrin glue only and an RNAi targeting Runx2, was evaluated with CT 3D reconstruction, histological analysis and biomechanical methods. CT showed a greater degree of new bone formation around the bone tunnel in the group treated with Runx2-ADSCs compared with the fibrin glue group and RNAi Runx2 group. Histology showed that treatment with Runx2-ADSCs led to a rapid and significant increase at the tendon-to-bone compared with the control groups. Biomechanical tests demonstrated higher tendon pullout strength in the Runx2-ADSCs group at early time points. The healing of the attachment in ACL reconstruction was enhanced by Runx2-ADSCs. PMID:26743583

  15. Use of a strontium-enriched calcium phosphate cement in accelerating the healing of soft-tissue tendon graft within the bone tunnel in a rabbit model of anterior cruciate ligament reconstruction.

    PubMed

    Kuang, G M; Yau, W P; Lu, W W; Chiu, K Y

    2013-07-01

    We investigated whether strontium-enriched calcium phosphate cement (Sr-CPC)-treated soft-tissue tendon graft results in accelerated healing within the bone tunnel in reconstruction of the anterior cruciate ligament (ACL). A total of 30 single-bundle ACL reconstructions using tendo Achillis allograft were performed in 15 rabbits. The graft on the tested limb was treated with Sr-CPC, whereas that on the contralateral limb was untreated and served as a control. At timepoints three, six, nine, 12 and 24 weeks after surgery, three animals were killed for histological examination. At six weeks, the graft-bone interface in the control group was filled in with fibrovascular tissue. However, the gap in the Sr-CPC group had already been completely filled in with new bone, and there was evidence of the early formation of Sharpey fibres. At 24 weeks, remodelling into a normal ACL-bone-like insertion was found in the Sr-CPC group. Coating of Sr-CPC on soft tissue tendon allograft leads to accelerated graft healing within the bone tunnel in a rabbit model of ACL reconstruction using Achilles tendon allograft. PMID:23814244

  16. Expert opinion: diagnosis and treatment of proximal hamstring tendinopathy

    PubMed Central

    Lempainen, Lasse; Johansson, Kristian; Banke, Ingo J.; Ranne, Juha; Mäkelä, Keijo; Sarimo, Janne; Niemi, Pekka; Orava, Sakari

    2015-01-01

    Summary Background: proximal hamstring tendinopathy (PHT) is a disabilitating disease often causing underperformance in the athletically demanding patients. The main symptom of PHT is lower gluteal pain especially during running or while prolonged sitting. Mainly affecting athletically active individuals, PHT is a considerable challenge for treating health care professionals. Purpose: this paper aims to concisely present the literature on PHT to guide health care professionals treating these patients and doing research on the subject. Methods: we reviewed the literature on PHT through literature search of scientific journal databases. Conclusions: as a tendinopathic pathology, it is a rather recently discovered exertion injury. As with other chronic tendon overuse injuries, current treatment strategies are unspecific with uncertain outcomes due to the unknown etiology of the tendon degeneration. Diagnostic features as well as both operative and non-operative treatments are evaluated from a clinical perspective, providing up to date information for clinicians and sports medicine therapists dealing with hamstring problems. Level of evidence: V. PMID:25878983

  17. Tendonitis (image)

    MedlinePlus

    ... tendon. It can occur as a result of injury, overuse, or with aging as the tendon loses elasticity. Any action that places prolonged repetitive strain on the forearm muscles can cause tendonitis. The ...

  18. Immediate effect of stretching and ultrasound on hamstring flexibility and proprioception.

    PubMed

    Cho, Sung-Hak; Kim, Soo-Han

    2016-06-01

    [Purpose] This research explored the positive effects of self-myofascial release on hamstring muscular flexibility and proprioception and investigated the effectiveness of the stretch combined with therapeutic ultrasound. [Subjects and Methods] This study included 30 healthy university students with no history of pain in the Achilles tendon or hamstring within the recent 6 months. Each participant completed two experiments. In the first experiment (MS), they completed self-myofascial stretching using a foam roller for 7 days. In the second experiment (MSU), the same participants performed the self-myofascial stretching after the 15-minute application of ultrasound. This study involved a pre- and post-test on hamstring muscle flexibility and hip joint proprioception. [Results] The use of self-myofascial stretching in the MS experiment had a significant effect on hamstring muscle flexibility and hip joint proprioception. However, the addition of ultrasound in the MSU experiment had no additive effect. [Conclusion] Self-myofascial stretching immediately increased hamstring muscle flexibility and improved hip joint proprioception, but the addition of pre-stretch ultra sound provided no further benefit. PMID:27390420

  19. Immediate effect of stretching and ultrasound on hamstring flexibility and proprioception

    PubMed Central

    Cho, Sung-Hak; Kim, Soo-Han

    2016-01-01

    [Purpose] This research explored the positive effects of self-myofascial release on hamstring muscular flexibility and proprioception and investigated the effectiveness of the stretch combined with therapeutic ultrasound. [Subjects and Methods] This study included 30 healthy university students with no history of pain in the Achilles tendon or hamstring within the recent 6 months. Each participant completed two experiments. In the first experiment (MS), they completed self-myofascial stretching using a foam roller for 7 days. In the second experiment (MSU), the same participants performed the self-myofascial stretching after the 15-minute application of ultrasound. This study involved a pre- and post-test on hamstring muscle flexibility and hip joint proprioception. [Results] The use of self-myofascial stretching in the MS experiment had a significant effect on hamstring muscle flexibility and hip joint proprioception. However, the addition of ultrasound in the MSU experiment had no additive effect. [Conclusion] Self-myofascial stretching immediately increased hamstring muscle flexibility and improved hip joint proprioception, but the addition of pre-stretch ultra sound provided no further benefit. PMID:27390420

  20. Secure fixation of femoral bone plug with a suspensory button in anatomical anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft

    PubMed Central

    TAKETOMI, SHUJI; INUI, HIROSHI; NAKAMURA, KENSUKE; YAMAGAMI, RYOTA; TAHARA, KEITARO; SANADA, TAKAKI; MASUDA, HIRONARI; TANAKA, SAKAE; NAKAGAWA, TAKUMI

    2015-01-01

    Purpose the efficacy and safety of using a suspensory button for femoral fixation in anatomical anterior cruciate ligament (ACL) reconstruction with bone-patellar tendon-bone (BPTB) graft have not been established. The purpose of the current study was to evaluate bone plug integration onto the femoral socket and migration of the bone plug and the EndoButton (EB) (Smith & Nephew, Andover, MA, USA) after rectangular tunnel ACL reconstruction with BPTB autograft. Methods thirty-four patients who underwent anatomical rectangular ACL reconstruction with BPTB graft using EB for femoral fixation and in whom three-dimensional (3D) computed tomography (CT) was performed one week and one year after surgery were included in this study. Bone plug integration onto the femoral socket, bone plug migration, soft tissue interposition, EB migration and EB rotation were evaluated on 3D CT. The clinical outcome was also assessed and correlated with the imaging outcomes. Results the bone plug was integrated onto the femoral socket in all cases. The incidence of bone plug migration, soft tissue interposition, EB migration and EB rotation was 15, 15, 9 and 56%, respectively. No significant association was observed between the imaging outcomes. The postoperative mean Lysholm score was 97.1 ± 5.0 points. The postoperative side-to-side difference, evaluated using a KT-2000 arthrometer, averaged 0.5 ± 1.3 mm. There were no complications associated with EB use. Imaging outcomes did not affect the postoperative KT side-to-side difference. Conclusions the EB is considered a reliable device for femoral fixation in anatomical rectangular tunnel ACL reconstruction with BPTB autograft. Level of evidence Level IV, therapeutic case series. PMID:26889465

  1. Allogeneic Versus Autologous Derived Cell Sources for Use in Engineered Bone-Ligament-Bone Grafts in Sheep Anterior Cruciate Ligament Repair

    PubMed Central

    Mahalingam, Vasudevan D.; Behbahani-Nejad, Nilofar; Horine, Storm V.; Olsen, Tyler J.; Smietana, Michael J.; Wojtys, Edward M.; Wellik, Deneen M.; Arruda, Ellen M.

    2015-01-01

    The use of autografts versus allografts for anterior cruciate ligament (ACL) reconstruction is controversial. The current popular options for ACL reconstruction are patellar tendon or hamstring autografts, yet advances in allograft technologies have made allogeneic grafts a favorable option for repair tissue. Despite this, the mismatched biomechanical properties and risk of osteoarthritis resulting from the current graft technologies have prompted the investigation of new tissue sources for ACL reconstruction. Previous work by our lab has demonstrated that tissue-engineered bone-ligament-bone (BLB) constructs generated from an allogeneic cell source develop structural and functional properties similar to those of native ACL and vascular and neural structures that exceed those of autologous patellar tendon grafts. In this study, we investigated the effectiveness of our tissue-engineered ligament constructs fabricated from autologous versus allogeneic cell sources. Our preliminary results demonstrate that 6 months postimplantation, our tissue-engineered auto- and allogeneic BLB grafts show similar histological and mechanical outcomes indicating that the autologous grafts are a viable option for ACL reconstruction. These data indicate that our tissue-engineered autologous ligament graft could be used in clinical situations where immune rejection and disease transmission may preclude allograft use. PMID:25397361

  2. Allogeneic versus autologous derived cell sources for use in engineered bone-ligament-bone grafts in sheep anterior cruciate ligament repair.

    PubMed

    Mahalingam, Vasudevan D; Behbahani-Nejad, Nilofar; Horine, Storm V; Olsen, Tyler J; Smietana, Michael J; Wojtys, Edward M; Wellik, Deneen M; Arruda, Ellen M; Larkin, Lisa M

    2015-03-01

    The use of autografts versus allografts for anterior cruciate ligament (ACL) reconstruction is controversial. The current popular options for ACL reconstruction are patellar tendon or hamstring autografts, yet advances in allograft technologies have made allogeneic grafts a favorable option for repair tissue. Despite this, the mismatched biomechanical properties and risk of osteoarthritis resulting from the current graft technologies have prompted the investigation of new tissue sources for ACL reconstruction. Previous work by our lab has demonstrated that tissue-engineered bone-ligament-bone (BLB) constructs generated from an allogeneic cell source develop structural and functional properties similar to those of native ACL and vascular and neural structures that exceed those of autologous patellar tendon grafts. In this study, we investigated the effectiveness of our tissue-engineered ligament constructs fabricated from autologous versus allogeneic cell sources. Our preliminary results demonstrate that 6 months postimplantation, our tissue-engineered auto- and allogeneic BLB grafts show similar histological and mechanical outcomes indicating that the autologous grafts are a viable option for ACL reconstruction. These data indicate that our tissue-engineered autologous ligament graft could be used in clinical situations where immune rejection and disease transmission may preclude allograft use. PMID:25397361

  3. Lower eccentric hamstring strength and single leg hop for distance predict hamstring injury in PETE students.

    PubMed

    Goossens, L; Witvrouw, E; Vanden Bossche, L; De Clercq, D

    2015-01-01

    Hamstring injuries have not been under research in physical education teacher education (PETE) students so far. Within the frame of the development of an injury prevention program, for this study we conducted an analysis of modifiable risk factors for hamstring injuries in PETE students. Hamstring injuries of 102 freshmen bachelor PETE students were registered prospectively during one academic year. Eighty-one students completed maximum muscle strength tests of hip extensors, hamstrings, quadriceps (isometric) and hamstrings (eccentric) at the start of the academic year. Sixty-nine of the latter completed a single leg hop for distance (SLHD). Risk factors for hamstring injuries were statistically detected using logistic regression. Sixteen hamstring injuries (0.16 injuries/student/academic year; 0.46 injuries/1000 h) occurred to 10 participants. Eight cases were included in the risk factor analysis. Lower eccentric hamstring strength (odds ratio (ODD) = 0.977; p = 0.043), higher isometric/eccentric hamstring strength ratio (ODD = 970.500; p = 0.019) and lower score on the SLHD (ODD = 0.884; p = 0.005) were significant risk factors for hamstring injury. A combination of eccentric hamstring strength test and SLHD could give a good risk analysis of hamstring injuries in PETE students. This might offer great perspectives for easily applicable screening in a clinical setting. PMID:25189278

  4. Tendon Innervation.

    PubMed

    Ackermann, Paul W; Salo, Paul; Hart, David A

    2016-01-01

    The regulation of tendon metabolism including the responses to loading is far from being well understood. During the last decade, however, accumulating data show that tendon innervation in addition to afferent functions, via efferent pathways has a regulatory role in tendon homeostasis via a wide range of neuromediators, which coordinate metabolic and neuro-inflammatory pathways.Innervation of intact healthy tendons is localized in the surrounding structures, i.e paratenon, endotenon and epitenon, whereas the tendon proper is practically devoid of neuronal supply. This anatomical finding reflects that the tendon metabolism is regulated from the tendon envelope, i.e. interfascicular matrix (see Chap. 1 ).Tendon innervation after injury and during repair, however, is found as extensive nerve ingrowth into the tendon proper, followed by a time-dependent emergence of different neuronal mediators, which amplify and fine-tune inflammatory and metabolic pathways in tendon regeneration. After healing nerve fibers retract to the tendon envelope.In tendinopathy innervation has been identified to consist of excessive and protracted nerve ingrowth in the tendon proper, suggesting pro-inflammatory, nociceptive and hypertrophic (degenerative) tissue responses.In metabolic disorders such as eg. diabetes impaired tendon healing has been established to be related to dysregulation of neuronal growth factors.Targeted approaches to the peripheral nervous system including neuronal mediators and their receptors may prove to be effective therapies for painful, degenerative and traumatic tendon disorders. PMID:27535247

  5. Do Newer-Generation Bioabsorbable Screws Become Incorporated into Bone at Two Years After ACL Reconstruction with Patellar Tendon Graft?

    PubMed Central

    Cox, Charles L.; Spindler, Kurt P.; Leonard, James P.; Morris, Brent J.; Dunn, Warren R.; Reinke, Emily K.

    2014-01-01

    Background: Bioabsorbable interference screws are used frequently for graft fixation in ACL (anterior cruciate ligament) reconstruction. The resorption properties of many available screws that are marketed as bioabsorbable are not well defined. The CALAXO (Smith & Nephew Endoscopy) and MILAGRO (DePuy Synthes) bioabsorbable screws contain polymers of poly(lactic-co-glycolic acid) (PLGA) plus additives to encourage osseointegration over time. The purpose of this study was to evaluate radiographic and magnetic resonance imaging (MRI) properties and compare patient-reported outcomes at a minimum of two years of follow-up after ACL reconstruction using CALAXO or MILAGRO bioabsorbable interference screws. Methods: A cohort of patients who underwent ACL reconstruction in which the fixation used was either CALAXO or MILAGRO screws returned for repeat radiographs for evaluation of tunnel widening, repeat MRI for evaluation of graft integrity and screw breakdown, and completion of the pain and symptom items of the KOOS (Knee injury and Osteoarthritis Outcome Score) questionnaire. Results: At a mean of three years (range, 2.5 to 4.0 years) after surgery, thirty-one patients with sixty-two CALAXO screws and thirty-six patients with seventy-two MILAGRO screws returned for repeat evaluation. Two blinded, independent reviewers found no significant differences between the two screw types when comparing radiographs for tibial or femoral tunnel widening or MRIs for graft integrity, tibial and femoral foreign body reactions, or femoral screw degradation. Both reviewers found a significant difference between the two screw types when comparing tibial screw degradation properties (p < 0.01). All analyzed CALAXO screws were rated as partially intact or degraded; the MILAGRO screws were more likely to be rated as intact. No significant differences were noted between the two screw types when comparing the two KOOS subscales. Conclusions: CALAXO screws in the tibial tunnel were more likely

  6. Extensive Loss of Tibialis Anterior Tendon: Surgical Repair With Split Tendon Transfer of Tibialis Posterior Tendon: A Case Report.

    PubMed

    Miyazaki, Tsuyoshi; Uchida, Kenzo; Kokubo, Yasuo; Inukai, Tomoo; Sakamoto, Takumi; Yamagishi, Atsushi; Kitade, Makoto; Baba, Hisatoshi

    2016-01-01

    Extensive damage of the tibialis anterior tendon is rare and mainly caused by trauma. Surgical treatment of these injuries can become challenging owing to the limited availability of autogenous graft resources for reconstruction of the defect. In the present case report, we describe a large defect in the midfoot soft tissue after a traffic injury, which included complete loss of the tibialis anterior tendon. The tendon was reconstructed by split tendon transfer of the tibialis posterior tendon without sacrificing function, which was confirmed by the follow-up examination at 6 years after injury. We believe split tendon transfer of the tibialis posterior tendon can be one of the treatment options for patients with extensive disruption of the tibialis anterior tendon. PMID:26213163

  7. Arthroscopic anterior cruciate ligament surgery: results of autogenous patellar tendon graft versus the Leeds-Keio synthetic graft five year follow-up of a prospective randomised controlled trial.

    PubMed

    Ghalayini, S R A; Helm, A T; Bonshahi, A Y; Lavender, A; Johnson, D S; Smith, R B

    2010-10-01

    We conducted a prospective, randomised controlled trial comparing anterior cruciate ligament reconstruction using middle third patellar tendon graft (PT) to synthetic Leeds-Keio (LK) ligament. The patients were randomised (26 PT, 24 LK). Subjective knee function was classified (Lysholm, Tegner activity, IKDC scores), laxity was measured (Lachman test, Stryker laxometer), and functional ability was assessed (one-hop test). There were no significant differences between Lysholm or IKDC scores at any stage by 5 years. Significant differences were found between the groups at 2 years for Tegner activity scores, laxity and one-hop testing. By 5 years there were no significant differences. Clinical equivalence was demonstrated between the two groups for the Lysholm score and one-hop test but not for the Tegner activity score at 5 years. The use of the LK ligament has been largely abandoned due to reports of its insufficiency. Our results demonstrate that it is not as inferior as one might expect. We conclude that the results of LK ligament ACL reconstruction are as acceptable as those using PT. It may provide an additional means of reconstruction where no suitable alternative is present. PMID:19861236

  8. Quadriceps tendon allografts as an alternative to Achilles tendon allografts: a biomechanical comparison.

    PubMed

    Mabe, Isaac; Hunter, Shawn

    2014-12-01

    Quadriceps tendon with a patellar bone block may be a viable alternative to Achilles tendon for anterior cruciate ligament reconstruction (ACL-R) if it is, at a minimum, a biomechanically equivalent graft. The objective of this study was to directly compare the biomechanical properties of quadriceps tendon and Achilles tendon allografts. Quadriceps and Achilles tendon pairs from nine research-consented donors were tested. All specimens were processed to reduce bioburden and terminally sterilized by gamma irradiation. Specimens were subjected to a three phase uniaxial tension test performed in a custom environmental chamber to maintain the specimens at a physiologic temperature (37 ± 2 °C) and misted with a 0.9 % NaCl solution. There were no statistical differences in seven of eight structural and mechanical between the two tendon types. Quadriceps tendons exhibited a significantly higher displacement at maximum load and significantly lower stiffness than Achilles tendons. The results of this study indicated a biomechanical equivalence of aseptically processed, terminally sterilized quadriceps tendon grafts with bone block to Achilles tendon grafts with bone block. The significantly higher displacement at maximum load, and lower stiffness observed for quadriceps tendons may be related to the failure mode. Achilles tendons had a higher bone avulsion rate than quadriceps tendons (86 % compared to 12 %, respectively). This was likely due to observed differences in bone block density between the two tendon types. This research supports the use of quadriceps tendon allografts in lieu of Achilles tendon allografts for ACL-R. PMID:24414293

  9. Hamstring Muscle Injuries, a Rehabilitation Protocol Purpose

    PubMed Central

    Valle, Xavier; L.Tol, Johannes; Hamilton, Bruce; Rodas, Gil; Malliaras, Peter; Malliaropoulos, Nikos; Rizo, Vicenc; Moreno, Marcel; Jardi, Jaume

    2015-01-01

    Context: Hamstring acute muscle injuries are prevalent in several sports including AFL football (Australian Football League), sprinting and soccer, and are often associated with prolonged time away from sport. Evidence Acquisition: In response to this, research into prevention and management of hamstring injury has increased, but epidemiological data shows no decline in injury and re-injury rates, suggesting that rehabilitation programs and return to play (RTP) criteria have to be improved. There continues to be a lack of consensus regarding how to assess performance, recovery and readiness to RTP, following hamstring strain injury. Results: The aim of this paper was to propose rehabilitation protocol for hamstring muscle injuries based on current basic science and research knowledge regarding injury demographics and management options. Conclusions: Criteria-based (subjective and objective) progression through the rehabilitation program will be outlined along with exercises for each phase, from initial injury to RTP. PMID:26715969

  10. Diagnosing Snapping Sartorius Tendon Secondary to a Meniscal Cyst Using Dynamic Ultrasound Avoids Incorrect Surgical Procedure

    PubMed Central

    Douglas, Robert J.; Martin, David

    2013-01-01

    We describe a case of painful snapping in the medial aspect of the knee of a 40-year-old man, following a knee hyperflexion injury. Dynamic real-time ultrasonography determined that the snapping was due to the distal tendon of sartorius passing over a medial meniscal cyst. The patient subsequently underwent arthroscopic decompression of the cyst instead of an inappropriate hamstring tendon harvest procedure, with complete resolution of symptoms. PMID:24198995

  11. Tendon repair

    MedlinePlus

    ... Cannon DL. Flexor and extensor tendon injuries. In: Canale ST, Beaty JH, eds. Campbell's Operative Orthopaedics . ... Shoulder Service, UCSF Department of Orthopaedic Surgery, San Francisco, CA. Also reviewed by David Zieve, MD, MHA, ...

  12. Unsuccessful regeneration of the semitendinosus tendon harvested for anterior cruciate ligament reconstruction: report of two cases.

    PubMed

    Nakamae, A; Ochi, M; Deie, M; Adachi, N

    2012-12-01

    Recent magnetic resonance imaging (MRI) and three-dimensional (3D) computed tomography (CT) analyses have demonstrated that semitendinosus tendon can regenerate at a high rate following harvesting the tendon for anterior cruciate ligament (ACL) reconstruction. Although it is known that the regeneration of the semitendinosus tendon does not occur in all the patients, the reason for this unsuccessful regeneration of the tendon in certain patients remains unknown. We recently encountered two cases in which regeneration of the semitendinosus tendon was unsuccessful because of apparent reasons. These patients experienced a sudden sharp pain in the posterior aspect of their thighs when their hamstring muscles were subjected to aggressive load at 3 and 4 weeks after surgery. At the follow-up examination conducted after 12 months, 3D CT imaging revealed unsuccessful regeneration of the semitendinosus tendons in both cases. Severe proximal retraction of the semitendinosus muscle belly was also confirmed. PMID:23123037

  13. Hamstring Injuries in Professional Football Players

    PubMed Central

    Cohen, Steven B.; Towers, Jeffrey D.; Zoga, Adam; Irrgang, Jay J.; Makda, Junaid; Deluca, Peter F.; Bradley, James P.

    2011-01-01

    Background: Magnetic resonance imaging (MRI) allows for detailed evaluation of hamstring injuries; however, there is no classification that allows prediction of return to play. Purpose: To correlate time for return to play in professional football players with MRI findings after acute hamstring strains and to create an MRI scoring scale predictive of return to sports. Study Design: Descriptive epidemiologic study. Methods: Thirty-eight professional football players (43 cases) sustained acute hamstring strains with MRI evaluation. Records were retrospectively reviewed, and MRIs were evaluated by 2 musculoskeletal radiologists, graded with a traditional radiologic grade, and scored with a new MRI score. Results were correlated with games missed. Results: Players missed 2.6 ± 3.1 games. Based on MRI, the hamstring injury involved the biceps femoris long head in 34 cases and the proximal and distal hamstrings in 25 and 22 cases, respectively. When < 50% of the muscle was involved, the average number of games missed was 1.8; if > 75%, then 3.2. Ten players had retraction, missing 5.5 games. By MRI, grade I injuries yielded an average of 1.1 missed games; grade II, 1.7; and grade III, 6.4. Players who missed 0 or 1 game had an MRI score of 8.2; 2 or 3 games, 11.1; and 4 or more games, 13.9. Conclusions: Rapid return to play (< 1 week) occurred with isolated long head of biceps femoris injures with < 50% of involvement and minimal perimuscular edema, correlating to grade I radiologic strain (MRI score < 10). Prolonged recovery (missing > 2 or 3 games) occurs with multiple muscle injury, injuries distal to musculotendinous junction, short head of biceps injury, > 75% involvement, retraction, circumferential edema, and grade III radiologic strain (MRI score > 15). Clinical Relevance: MRI grade and this new MRI score are useful in determining severity of injury and games missed—and, ideally, predicting time missed from sports. PMID:23016038

  14. Secondary repair of flexor tendon injuries.

    PubMed

    Battiston, B; Triolo, P F; Bernardi, A; Artiaco, S; Tos, P

    2013-03-01

    Tendon adhesions or even secondary ruptures causing severe hand functional impairment still represent a frequent complication after repair of flexor tendon injuries. Secondary treatment of these problems includes tenolysis, one or two stages flexor tendons reconstruction by grafts or even the use of tendon prosthesis. The mechanism and severity of injury, the status of the surrounding tissues and injured finger, the presence of associated lesions, the age of the patient, post-operative management, patient motivation and the surgeon's skill, may all have implications in the final outcome of the tendon reconstruction. A correct evaluation of the problem by means of classifications such as the one described by Boyes, may help the surgeon in choosing the appropriate technique. PMID:23347767

  15. A 3-Dimensional Anatomic Study of the Distal Biceps Tendon

    PubMed Central

    Walton, Christine; Li, Zhi; Pennings, Amanda; Agur, Anne; Elmaraghy, Amr

    2015-01-01

    Background Complete rupture of the distal biceps tendon from its osseous attachment is most often treated with operative intervention. Knowledge of the overall tendon morphology as well as the orientation of the collagenous fibers throughout the musculotendinous junction are key to intraoperative decision making and surgical technique in both the acute and chronic setting. Unfortunately, there is little information available in the literature. Purpose To comprehensively describe the morphology of the distal biceps tendon. Study Design Descriptive laboratory study. Methods The distal biceps terminal musculature, musculotendinous junction, and tendon were digitized in 10 cadaveric specimens and data reconstructed using 3-dimensional modeling. Results The average length, width, and thickness of the external distal biceps tendon were found to be 63.0, 6.0, and 3.0 mm, respectively. A unique expansion of the tendon fibers within the distal muscle was characterized, creating a thick collagenous network along the central component between the long and short heads. Conclusion This study documents the morphologic parameters of the native distal biceps tendon. Reconstruction may be necessary, especially in chronic distal biceps tendon ruptures, if the remaining tendon morphology is significantly compromised compared with the native distal biceps tendon. Knowledge of normal anatomical distal biceps tendon parameters may also guide the selection of a substitute graft with similar morphological characteristics. Clinical Relevance A thorough description of distal biceps tendon morphology is important to guide intraoperative decision making between primary repair and reconstruction and to better select the most appropriate graft. The detailed description of the tendinous expansion into the muscle may provide insight into better graft-weaving and suture-grasping techniques to maximize proximal graft incorporation. PMID:26665092

  16. Augmentation of tendon-to-bone healing.

    PubMed

    Atesok, Kivanc; Fu, Freddie H; Wolf, Megan R; Ochi, Mitsuo; Jazrawi, Laith M; Doral, M Nedim; Lubowitz, James H; Rodeo, Scott A

    2014-03-19

    Tendon-to-bone healing is vital to the ultimate success of the various surgical procedures performed to repair injured tendons. Achieving tendon-to-bone healing that is functionally and biologically similar to native anatomy can be challenging because of the limited regeneration capacity of the tendon-bone interface. Orthopaedic basic-science research strategies aiming to augment tendon-to-bone healing include the use of osteoinductive growth factors, platelet-rich plasma, gene therapy, enveloping the grafts with periosteum, osteoconductive materials, cell-based therapies, biodegradable scaffolds, and biomimetic patches. Low-intensity pulsed ultrasound and extracorporeal shockwave treatment may affect tendon-to-bone healing by means of mechanical forces that stimulate biological cascades at the insertion site. Application of various loading methods and immobilization times influence the stress forces acting on the recently repaired tendon-to-bone attachment, which eventually may change the biological dynamics of the interface. Other approaches, such as the use of coated sutures and interference screws, aim to deliver biological factors while achieving mechanical stability by means of various fixators. Controlled Level-I human trials are required to confirm the promising results from in vitro or animal research studies elucidating the mechanisms underlying tendon-to-bone healing and to translate these results into clinical practice. PMID:24647509

  17. Greater fear of re-injury and increased tibial translation in patients who later sustain an ACL graft rupture or a contralateral ACL rupture: a pilot study.

    PubMed

    Tagesson, Sofi; Kvist, Joanna

    2016-01-01

    The aim was to compare fear of re-injury, patient reported function, static and dynamic tibial translation and muscle strength assessed before and 5 weeks after an anterior cruciate ligament (ACL) reconstruction between individuals who sustained a subsequent ACL graft rupture or a contralateral ACL injury within 5 years after the reconstruction, and individuals with no subsequent injury. Nineteen patients were investigated before, and 5 weeks after an ACL reconstruction with a quadruple hamstring tendon graft. At 5 years follow up, 3 patients had sustained an ACL graft rupture and 2 patients had sustained a contralateral ACL rupture. Fear of re-injury, confidence with the knee, patient reported function, activity level, static and dynamic tibial translation and muscle strength were assessed. The re-injured group reported greater fear of re-injury and had greater static tibial translation in both knees before the ACL reconstruction compared to those who did not sustain another ACL injury. There were no other differences between groups. In conclusion, fear of re-injury and static tibial translation before the index ACL reconstruction were greater in patients who later on suffered an ACL graft rupture or a contralateral ACL rupture. These factors may predict a subsequent ACL injury. PMID:25894209

  18. Osteointegration of soft tissue grafts within the bone tunnels in anterior cruciate ligament reconstruction can be enhanced.

    PubMed

    Kuang, Guan-Ming; Yau, W P; Lu, William W; Chiu, K Y

    2010-08-01

    Anterior cruciate ligament reconstruction with a soft tissue autograft (hamstring autograft) has grown in popularity in the last 10 years. However, the issues of a relatively long healing time and an inferior histological healing result in terms of Sharpey-like fibers connection in soft tissue grafts are still unsolved. To obtain a promising outcome in the long run, prompt osteointegration of the tendon graft within the bone tunnel is essential. In recent decades, numerous methods have been reported to enhance osteointegration of soft tissue graft in the bone tunnel. In this article, we review the current literature in this research area, mainly focusing on strategies applied to the local bone tunnel environment. Biological strategies such as stem cell and gene transfer technology, as well as the local application of specific growth factors have been reported to yield exciting results. The use of biological bone substitute and physical stimulation also obtained promising results. Artificially engineered tissue has promise as a solution to the problem of donor site morbidity. Despite these encouraging results, the current available evidence is still experimental. Further clinical studies in terms of randomized control trial in the future should be conducted to extrapolate these basic science study findings into clinical practice. PMID:19779894

  19. Tendon latch

    SciTech Connect

    Watkins, B. J.

    1985-01-01

    A latch connects tendons run from a floating platform to a socket in a foundation on the sea floor. The latch includes a latch body having a plurality of dogs disposed within and urgible outward from the latch body. A piston is releasably disposed within the latch body above the dogs and moves downwardly when released to urge the dogs outwardly from the body into latching engagement with the socket. A trigger mechanism in the latch releases the piston when the latch body lands in the socket and contacts a trigger pin projecting upwardly from the bottom of the socket. A series of wedges are disposed exteriorally on the body and inhibit lateral movement of the body relative to the socket when the tendon is subjected to a cycle bending loads.

  20. Posterior Tibial Tendon Dysfunction

    MedlinePlus

    ... when the posterior tibial tendon becomes inflamed or torn. As a result, the tendon may not be ... repetitive use. Once the tendon becomes inflamed or torn, the arch will slowly fall (collapse) over time. ...

  1. Pitfalls during biomechanical testing - Evaluation of different fixation methods for measuring tendons endurance properties.

    PubMed

    Hangody, Gy; Pánics, G; Szebényi, G; Kiss, R; Hangody, L; Pap, K

    2016-03-01

    The goal of the study was to find a proper technique to fix tendon grafts into an INSTRON loading machine. From 8 human cadavers, 40 grafts were collected. We removed the bone-patella tendon-bone grafts, the semitendinosus and gracilis tendons, the quadriceps tendon-bone grafts, the Achilles tendons, and the peroneus longus tendons from each lower extremity. We tested the tendon grafts with five different types of fixation devices: surgical thread (Premicron 3), general mounting clamp, wire mesh, cement fixation, and a modified clamp for an INSTRON loading machine. The mean failure load in case of surgical thread fixation was (381N ± 26N). The results with the general clamp were (527N ± 45N). The wire meshes were more promising (750N ± 21N), but did not reach the outcomes we desired. Easy slippages of the ends of the tendons from the cement encasements were observed (253N ± 18N). We then began to use Shi's clamp that could produce 977N ± 416N peak force. We combined Shi's clamp with freezing of the graft and the rupture of the tendon itself demonstrated an average force of 2198 N ± 773N. We determined that our modified frozen clamp fixed the specimens against high tensile forces. PMID:27030630

  2. ACL Reconstruction: Choosing the Graft

    PubMed Central

    Cerulli, Giuliano; Placella, Giacomo; Sebastiani, Enrico; Tei, Matteo Maria; Speziali, Andrea; Manfreda, Francesco

    2013-01-01

    Summary Rupture of the anterior cruciate ligament is one of the most common ligament injuries in sports traumatology. The need for surgical anterior cruciate ligament reconstruction is justified by its anatomical characteristics. Key considerations when choosing a graft include the potential for bone integration and the risk of failure. Bone sclerosis around the tunnel affects the integration of the graft. For this reason, one aspect upon which orthopedic surgeons should focus is the biology of the bone-graft interface. Although the BPTB graft is still used, hamstrings and synthetic grafts have become increasingly widespread and popular over the years. An allograft certainly requires more long-term follow-up to validate its use in response to functional, clinical and biological requirements. PMID:25606507

  3. Hamstrings functional properties in athletes with high musculo-skeletal flexibility.

    PubMed

    Moltubakk, M M; Eriksrud, O; Paulsen, G; Seynnes, O R; Bojsen-Møller, J

    2016-06-01

    The purpose of this study was to examine whether athletes with highly flexible hamstring muscle-tendon units display different passive and contractile mechanical properties compared with controls. Flexibility, passive, and active torque-angle properties were assessed in 21 female elite rhythmic gymnasts and 16 female age-matched athletes. Passive resistance to stretch was measured during knee extension with the hip fixed at 100° of flexion. Concentric isokinetic maximal voluntary knee flexion and extension torques were measured at 60°/s in the same position. Tests of flexibility and passive resistance to stretch indicated a greater flexibility in the gymnasts. Despite no differences between groups in knee flexion and extension peak torque, gymnasts reached knee flexion peak torque at more extended positions (longer muscle lengths) and displayed significantly different torque-angle relations. When active torque was corrected for passive resistance to stretch, differences increased, gymnasts producing more work, and maintaining ≥ 70% of peak torque over a larger range of joint excursion. In conclusion, individuals with a higher flexibility of the hamstrings MTU present a different torque-angle profile, favoring the production of flexion torque toward extended knee positions, displaying larger functional range of motion and a higher mechanical work output during knee flexion. PMID:26031482

  4. Hamstring Injuries--An Examination of Possible Causes.

    ERIC Educational Resources Information Center

    Liemohn, Wendell

    On the basis of research, the following characteristics appear to be important factors relative to precluding hamstring strains in sprinters: bilaterality relative to hamstring and quadricep strength development, optimum strength ratios between ipsilateral antagonists throughout the range of movement, and above-normal hip-joint flexibility. (JD)

  5. Tendon, tendon healing, hyperlipidemia and statins

    PubMed Central

    Esenkaya, Irfan; Unay, Koray

    2011-01-01

    Summary Both hyperlipidemia and metabolic syndrome have adverse effect on tendon structure. Atorvastatin is most widely used antihyperlipidemic drug. Statins have adverse effects on the tendon. Many studies have analyzed the relationship between atorvastatin and skeletal muscles. Atorvastatin administered after the surgical repair of a ruptured tendon appears to affect revascularization, collagenization, inflammatory cell infiltration, and collagen construction. Therefore, further investigations on the effects of atorvastatin on tendon healing are needed. PMID:23738266

  6. Biomimetic Scaffold Design for Functional and Integrative Tendon Repair

    PubMed Central

    Zhang, Xinzhi; Bogdanowicz, Danielle; Erisken, Cevat; Lee, Nancy M.; Lu, Helen H.

    2012-01-01

    Rotator cuff tears represent the most common shoulder injuries in the United States. The debilitating effect of this degenerative condition coupled with the high incidence of failure associated with existing graft choices underscore the clinical need for alternative grafting solutions. The two critical design criteria for the ideal tendon graft would require the graft to not only exhibit physiologically relevant mechanical properties but also be able to facilitate functional graft integration by promoting the regeneration of the native tendon-to-bone interface. Centered on these design goals, this review will highlight current approaches to functional and integrative tendon repair. In particular, the application of biomimetic design principles through the use of nanofiber- and nanocomposite-based scaffolds for tendon tissue engineering will be discussed. This review will begin with nanofiber-based approaches to functional tendon repair, followed by a section highlighting the exciting research on tendon-to-bone interface regeneration, with an emphasis on implementation of strategic biomimicry in nanofiber scaffold design and the concomitant formation of graded multi-tissue systems for integrative soft tissue repair. This review will conclude with a summary and future directions section. PMID:22244070

  7. The role of mechanobiology in tendon healing.

    PubMed

    Killian, Megan L; Cavinatto, Leonardo; Galatz, Leesa M; Thomopoulos, Stavros

    2012-02-01

    Mechanical cues affect tendon healing, homeostasis, and development in a variety of settings. Alterations in the mechanical environment are known to result in changes in the expression of extracellular matrix proteins, growth factors, transcription factors, and cytokines that can alter tendon structure and cell viability. Loss of muscle force in utero or in the immediate postnatal period delays tendon and enthesis development. The response of healing tendons to mechanical load varies depending on anatomic location. Flexor tendons require motion to prevent adhesion formation, yet excessive force results in gap formation and subsequent weakening of the repair. Excessive motion in the setting of anterior cruciate ligament reconstruction causes accumulation of macrophages, which are detrimental to tendon graft healing. Complete removal of load is detrimental to rotator cuff healing; yet, large forces are also harmful. Controlled loading can enhance healing in most settings; however, a fine balance must be reached between loads that are too low (leading to a catabolic state) and too high (leading to microdamage). This review will summarize existing knowledge of the mechanobiology of tendon development, homeostasis, and healing. PMID:22244066

  8. Muscle activation during various hamstring exercises.

    PubMed

    McAllister, Matt J; Hammond, Kelley G; Schilling, Brian K; Ferreria, Lucas C; Reed, Jacob P; Weiss, Lawrence W

    2014-06-01

    The dorsal muscles of the lower torso and extremities have often been denoted the "posterior chain." These muscles are used to support the thoracic and lumbar spine and peripheral joints, including the hip, knee, and ankle on the dorsal aspect of the body. This study investigated the relative muscle activity of the hamstring group and selected surrounding musculature during the leg curl, good morning, glute-ham raise, and Romanian deadlift (RDL). Twelve healthy, weight-trained men performed duplicate trials of single repetitions at 85% 1-repetition maximum for each lift in random order, during which surface electromyography and joint angle data were obtained. Repeated measures analysis of variance across the 4 exercises was performed to compare the activity from the erector spinae (ES), gluteus medius (GMed), semitendinosus (ST), biceps femoris (BF), and medial gastrocnemius (MGas). Significant differences (p ≤ 0.05) were noted in eccentric muscle activity between exercise for the MGas (p < 0.027), ST (p < 0.001), BF (p < 0.001), and ES (p = 0.032), and in concentric muscle activity, for the ES (p < 0.001), BF (p = 0.010), ST (p = 0.009), MGas (p < 0.001), and the GMed (p = 0.018). Bonferroni post hoc analysis revealed significant pairwise differences during eccentric actions for the BF, ST, and MGas. Post hoc analysis also revealed significant pairwise differences during concentric actions for the ES, BF, ST, MGas, and GMed. Each of these showed effect sizes that are large or greater. The main findings of this investigation are that the ST is substantially more active than the BF among all exercises, and hamstring activity was maximized in the RDL and glute-ham raise. Therefore, athletes and coaches who seek to maximize the involvement of the hamstring musculature should consider focusing on the glute-ham raise and RDL. PMID:24149748

  9. Conservative Treatment of Subacute Proximal Hamstring Tendinopathy Using Eccentric Exercises Performed With a Treadmill: A Case Report

    PubMed Central

    CUSHMAN, DANIEL; RHO, MONICA E.

    2015-01-01

    STUDY DESIGN Case report. BACKGROUND Proximal hamstring tendinopathy in runners is characterized by pain with passive hip flexion with the knee extended, active hip extension, and pain with sitting. Relatively little literature exists on the condition, and publications on nonsurgical treatment protocols are even more scarce. Surgical intervention, which comprises the majority of literature for treatment of this condition, is an option for cases that fail to respond to nonsurgical treatment. CASE DESCRIPTION The patient was a 34-year-old, otherwise healthy male triathlete with unilateral proximal hamstring tendinopathy diagnosed by ultrasound, who had pain only with running and prolonged sitting. After he failed to respond to 4 weeks of eccentric knee flexion and lumbopelvic musculature strengthening exercises, an eccentric hip extensor strengthening program using a treadmill was initiated. This treadmill exercise was performed on a daily basis, in addition to a lumbopelvic musculature strengthening program. OUTCOMES The patient noted a decrease in pain within 2 weeks of initiating the new exercise, and was able to return to gradual running after 4 weeks and to speed training after 12 weeks. He returned to competition shortly thereafter and had no recurrence for 12 months after the initiation of therapy. His score on the Victorian Institute of Sport Assessment-proximal hamstring tendons improved from 23 on initial presentation to 83 at 12 weeks after the initiation of therapy. DISCUSSION We described the management of a triathlete with subacute proximal hamstring tendinopathy, who responded well to nonsurgical treatment using eccentric hip extension strengthening using a treadmill. LEVEL OF EVIDENCE Therapy, level 4. PMID:25996362

  10. Functionally distinct tendon fascicles exhibit different creep and stress relaxation behaviour

    PubMed Central

    Legerlotz, Kirsten; Demirci, Taylan; Klemt, Christian; Riley, Graham P; Screen, Hazel RC

    2014-01-01

    Most overuse tendinopathies are thought to be associated with repeated microstrain below the failure threshold, analogous to the fatigue failure that affects materials placed under repetitive loading. Investigating the progression of fatigue damage within tendons is therefore of critical importance. There are obvious challenges associated with the sourcing of human tendon samples for in vitro analysis so animal models are regularly adopted. However, data indicates that fatigue life varies significantly between tendons of different species and with different stresses in life. Positional tendons such as rat tail tendon or the bovine digital extensor are commonly applied in in vitro studies of tendon overuse, but there is no evidence to suggest their behaviour is indicative of the types of human tendon particularly prone to overuse injuries. In this study, the fatigue response of the largely positional digital extensor and the more energy storing deep digital flexor tendon of the bovine hoof were compared to the semitendinosus tendon of the human hamstring. Fascicles from each tendon type were subjected to either stress or strain controlled fatigue loading (cyclic creep or cyclic stress relaxation respectively). Gross fascicle mechanics were monitored after cyclic stress relaxation and the mean number of cycles to failure investigated with creep loading. Bovine extensor fascicles demonstrated the poorest fatigue response, while the energy storing human semitendinosus was the most fatigue resistant. Despite the superior fatigue response of the energy storing tendons, confocal imaging suggested a similar degree of damage in all three tendon types; it appears the more energy storing tendons are better able to withstand damage without detriment to mechanics. PMID:24285289

  11. Endoscopic adhesiolysis for extensive tibialis posterior tendon and Achilles tendon adhesions following compound tendon rupture

    PubMed Central

    Lui, Tun Hing

    2013-01-01

    Tendon adhesion is one of the most common causes of disability following tendon surgery. A case of extensive peritendinous adhesions of the Achilles tendon and tibialis posterior tendon after compound rupture of the tendons was reported. This was managed by endoscopic adhesiolysis of both tendons. The endoscopic approach allows early postoperative mobilisation which can relieve the tendon adhesion. PMID:24045762

  12. Prevalence and influence of tibial tunnel widening after isolated anterior cruciate ligament reconstruction using patella-bone-tendon-bone-graft: long-term follow-up.

    PubMed

    Struewer, Johannes; Efe, Turgay; Frangen, Thomas Manfred; Schwarting, Tim; Buecking, Benjamin; Ruchholtz, Steffen; Schüttler, Karl Friedrich; Ziring, Ewgeni

    2012-05-01

    The aim of the present study was to evaluate incidence, degree and impact of tibial tunnel widening (TW) on patient-reported long-term clinical outcome, knee joint stability and prevalence of osteoarthritis (OA) after isolated anterior cruciate ligament (ACL) reconstruction. On average, 13.5 years after ACL reconstruction via patella-bone-tendon-bone autograft, 73 patients have been re-evaluated. Inclusion criteria consisted of an isolated anterior cruciate ligament rupture and reconstruction, a minimum of 10-year follow-up and no previous anterior cruciate ligament repair or associated intra-articular lesions. Clinical evaluation was performed via the International Knee Documentation Committee (IKDC) score and the Tegner and Lysholm scores. Instrumental anterior laxity testing was carried out with the KT-1000™ arthrometer. The degree of degenerative changes and the prevalence of osteoarthritis were assessed with the Kellgren-Lawrence score. Tibial tunnel enlargement was radiographically evaluated on both antero-posterior and lateral views under establishment of 4 degrees of tibial tunnel widening by measuring the actual tunnel diameters in mm on the sclerotic margins of the inserted tunnels on 3 different points (T1-T3). Afterwards, a conversion of the absolute values in mm into a 4 staged ratio, based on the comparison to the results of the initial drill-width, should provide a better quantification and statistical analysis. Evaluation was performed postoperatively as well as on 2 year follow-up and 13 years after ACL reconstruction. Minimum follow-up was 10 years. 75% of patients were graded A or B according to IKDC score. The mean Lysholm score was 90.2±4.8 (25-100). Radiological assessment on long-term follow-up showed in 45% a grade I, in 24% a grade II, in 17% a grade III and in additional 12% a grade IV enlargement of the tibial tunnel. No evident progression of TW was found in comparison to the 2 year results. Radiological evaluation revealed

  13. Decellularized and Engineered Tendons as Biological Substitutes: A Critical Review

    PubMed Central

    Lovati, Arianna B.; Bottagisio, Marta; Moretti, Matteo

    2016-01-01

    Tendon ruptures are a great burden in clinics. Finding a proper graft material as a substitute for tendon repair is one of the main challenges in orthopaedics, for which the requirement of a biological scaffold would be different for each clinical application. Among biological scaffolds, the use of decellularized tendon-derived matrix increasingly represents an interesting approach to treat tendon ruptures. We analyzed in vitro and in vivo studies focused on the development of efficient protocols for the decellularization and for the cell reseeding of the tendon matrix to obtain medical devices for tendon substitution. Our review considered also the proper tendon source and preclinical animal models with the aim of entering into clinical trials. The results highlight a wide panorama in terms of allogenic or xenogeneic tendon sources, specimen dimensions, physical or chemical decellularization techniques, and the cell type variety for reseeding from terminally differentiated to undifferentiated mesenchymal stem cells and their static or dynamic culture employed to generate implantable constructs tested in different animal models. We try to identify the most efficient approach to achieve an optimal biological scaffold for biomechanics and intrinsic properties, resembling the native tendon and being applicable in clinics in the near future, with particular attention to the Achilles tendon substitution. PMID:26880985

  14. Immediate Effects of Neurodynamic Sliding versus Muscle Stretching on Hamstring Flexibility in Subjects with Short Hamstring Syndrome.

    PubMed

    Castellote-Caballero, Yolanda; Valenza, Maríe C; Puentedura, Emilio J; Fernández-de-Las-Peñas, César; Alburquerque-Sendín, Francisco

    2014-01-01

    Background. Hamstring injuries continue to affect active individuals and although inadequate muscle extensibility remains a commonly accepted factor, little is known about the most effective method to improve flexibility. Purpose. To determine if an isolated neurodynamic sciatic sliding technique would improve hamstring flexibility to a greater degree than stretching or a placebo intervention in asymptomatic subjects with short hamstring syndrome (SHS). Study Design. Randomized double-blinded controlled trial. Methods. One hundred and twenty subjects with SHS were randomized to 1 of 3 groups: neurodynamic sliding, hamstring stretching, and placebo control. Each subject's dominant leg was measured for straight leg raise (SLR) range of motion (ROM) before and after interventions. Data were analyzed with a 3 × 2 mixed model ANOVA followed by simple main effects analyses. Results. At the end of the study, more ROM was observed in the Neurodynamic and Stretching groups compared to the Control group and more ROM in the Neurodynamic group compared to Stretching group. Conclusion. Findings suggest that a neurodynamic sliding technique will increase hamstring flexibility to a greater degree than static hamstring stretching in healthy subjects with SHS. Clinical Relevance. The use of neurodynamic sliding techniques to improve hamstring flexibility in sports may lead to a decreased incidence in injuries; however, this needs to be formally tested. PMID:26464889

  15. Laminar Tendon Composites with Enhanced Mechanical Properties

    PubMed Central

    Alberti, Kyle A.; Sun, Jeong-Yun; Illeperuma, Widusha R.; Suo, Zhigang; Xu, Qiaobing

    2015-01-01

    Purpose A strong isotropic material that is both biocompatible and biodegradable is desired for many biomedical applications, including rotator cuff repair, tendon and ligament repair, vascular grafting, among others. Recently, we developed a technique, called “bioskiving” to create novel 2D and 3D constructs from decellularized tendon, using a combination of mechanical sectioning, and layered stacking and rolling. The unidirectionally aligned collagen nanofibers (derived from sections of decellularized tendon) offer good mechanical properties to the constructs compared with those fabricated from reconstituted collagen. Methods In this paper, we studied the effect that several variables have on the mechanical properties of structures fabricated from tendon slices, including crosslinking density and the orientation in which the fibers are stacked. Results We observed that following stacking and crosslinking, the strength of the constructs is significantly improved, with crosslinked sections having an ultimate tens ile strength over 20 times greater than non-crosslinked samples, and a modulus nearly 50 times higher. The mechanism of the mechanical failure mode of the tendon constructs with or without crosslinking was also investigated. Conclusions The strength and fiber organization, combined with the ability to introduce transversely isotropic mechanical properties makes the laminar tendon composites a biocompatiable material that may find future use in a number of biomedical and tissue engineering applications. PMID:25691802

  16. Pressurized liquid filled tendons

    SciTech Connect

    Burns, G.E.

    1987-05-12

    This patent describes an apparatus for detecting a leak in a tension leg platform tendon, comprising: a fluid-tight tensioned tubular tendon, the tendon connected on its upper end to a buoyant offshore structure and on its lower end to an anchor means. The anchor means is connected to the sea floor; means for supplying liquid to the tendon; means for pressurizing the liquid in excess of the maximum hydrostatic pressure exerted by the sea water on the tendon; and means for monitoring pressure, the means monitoring variations in liquid pressure to the tendon.

  17. Hamstring Injuries in the Athlete: Diagnosis, Treatment, and Return to Play.

    PubMed

    Chu, Samuel K; Rho, Monica E

    2016-01-01

    Hamstring injuries are very common in athletes. Acute hamstring strains can occur with high-speed running or with excessive hamstring lengthening. Athletes with proximal hamstring tendinopathy often do not report a specific inciting event; instead, they develop the pathology from chronic overuse. A thorough history and physical examination is important to determine the appropriate diagnosis and rule out other causes of posterior thigh pain. Conservative management of hamstring strains involves a rehabilitation protocol that gradually increases intensity and range of motion, and progresses to sport-specific and neuromuscular control exercises. Eccentric strengthening exercises are used for management of proximal hamstring tendinopathy. Studies investigating corticosteroid and platelet-rich plasma injections have mixed results. Magnetic resonance imaging and ultrasound are effective for identification of hamstring strains and tendinopathy but have not demonstrated correlation with return to play. The article focuses on diagnosis, treatment, and return-to-play considerations for acute hamstring strains and proximal hamstring tendinopathy in the athlete. PMID:27172083

  18. Prediction of hamstring injury in professional soccer players by isokinetic measurements

    PubMed Central

    Dauty, Marc; Menu, Pierre; Fouasson-Chailloux, Alban; Ferréol, Sophie; Dubois, Charles

    2016-01-01

    Summary Objectives previous studies investigating the ability of isokinetic strength ratios to predict hamstring injuries in soccer players have reported conflicting results. Hypothesis to determine if isokinetic ratios are able to predict hamstring injury occurring during the season in professional soccer players. Study Design case-control study; Level of evidence: 3. Methods from 2001 to 2011, 350 isokinetic tests were performed in 136 professional soccer players at the beginning of the soccer season. Fifty-seven players suffered hamstring injury during the season that followed the isokinetic tests. These players were compared with the 79 uninjured players. The bilateral concentric ratio (hamstring-to-hamstring), ipsilateral concentric ratio (hamstring-to-quadriceps), and mixed ratio (eccentric/concentric hamstring-to-quadriceps) were studied. The predictive ability of each ratio was established based on the likelihood ratio and post-test probability. Results the mixed ratio (30 eccentric/240 concentric hamstring-to-quadriceps) <0.8, ipsilateral ratio (180 concentric hamstring-to-quadriceps) <0.47, and bilateral ratio (60 concentric hamstring-to-hamstring) <0.85 were the most predictive of hamstring injury. The ipsilateral ratio <0.47 allowed prediction of the severity of the hamstring injury, and was also influenced by the length of time since administration of the isokinetic tests. Conclusion isokinetic ratios are useful for predicting the likelihood of hamstring injury in professional soccer players during the competitive season. PMID:27331039

  19. Transverse Compression of Tendons.

    PubMed

    Samuel Salisbury, S T; Paul Buckley, C; Zavatsky, Amy B

    2016-04-01

    A study was made of the deformation of tendons when compressed transverse to the fiber-aligned axis. Bovine digital extensor tendons were compression tested between flat rigid plates. The methods included: in situ image-based measurement of tendon cross-sectional shapes, after preconditioning but immediately prior to testing; multiple constant-load creep/recovery tests applied to each tendon at increasing loads; and measurements of the resulting tendon displacements in both transverse directions. In these tests, friction resisted axial stretch of the tendon during compression, giving approximately plane-strain conditions. This, together with the assumption of a form of anisotropic hyperelastic constitutive model proposed previously for tendon, justified modeling the isochronal response of tendon as that of an isotropic, slightly compressible, neo-Hookean solid. Inverse analysis, using finite-element (FE) simulations of the experiments and 10 s isochronal creep displacement data, gave values for Young's modulus and Poisson's ratio of this solid of 0.31 MPa and 0.49, respectively, for an idealized tendon shape and averaged data for all the tendons and E = 0.14 and 0.10 MPa for two specific tendons using their actual measured geometry. The compression load versus displacement curves, as measured and as simulated, showed varying degrees of stiffening with increasing load. This can be attributed mostly to geometrical changes in tendon cross section under load, varying according to the initial 3D shape of the tendon. PMID:26833218

  20. Circumflex femoral vein thrombosis misinterpreted as acute hamstring strain.

    PubMed

    Papastergiou, Stergios G; Koukoulias, Nikolaos E; Tsitouridis, Ioannis; Natsis, Constantinos; Parisis, Constantinos A

    2007-07-01

    The case of a 24-year-old female professional, long-distance runner who presented with acute proximal posterior thigh pain is reported. History and clinical findings were consistent with acute hamstring strain but MRI demonstrated circumflex femoral vein thrombosis. This is the first case of proximal posterior thigh pain caused by circumflex femoral vein thrombosis reported in the literature. Doctors dealing with sports injuries should be aware of this clinical entity that mimics hamstring strain. PMID:17224439

  1. Circumflex femoral vein thrombosis misinterpreted as acute hamstring strain

    PubMed Central

    Papastergiou, Stergios G; Koukoulias, Nikolaos E; Tsitouridis, Ioannis; Natsis, Constantinos; Parisis, Constantinos A

    2007-01-01

    The case of a 24‐year‐old female professional, long‐distance runner who presented with acute proximal posterior thigh pain is reported. History and clinical findings were consistent with acute hamstring strain but MRI demonstrated circumflex femoral vein thrombosis. This is the first case of proximal posterior thigh pain caused by circumflex femoral vein thrombosis reported in the literature. Doctors dealing with sports injuries should be aware of this clinical entity that mimics hamstring strain. PMID:17224439

  2. High hamstring tendinopathy in 3 female long distance runners

    PubMed Central

    White, Kristin E.

    2011-01-01

    Objective The purpose of this case report is to describe and discuss the clinical presentation, diagnosis, and management of 3 female long distance runners with high hamstring tendinopathy. Clinical Features Three female runners presented to a chiropractic office with proximal hamstring pain that was aggravated by running. Increasing mileage, hills, and/or interval training preceded the onset of symptoms in each case. The subjects all displayed weakness of the hip abductors, pelvic joint dysfunction, hamstring tightness, and ischial tuberosity tenderness. Other clinical findings included overpronation, proprioceptive weakness, and lumbar dysfunction. Intervention and Outcome All 3 patients were treated with Graston Instrument Assisted Soft Tissue Mobilization, lumbopelvic manipulation, and electrical muscle stimulation with ultrasound. Active exercise focused on hamstring stretching and strengthening, gluteal strengthening, and proprioceptive training. The 3 runners seen in this clinic had resolution of hamstring pain in an average of 13 treatments and were able to continue competing without restriction. Conclusion Runners with high hamstring tendinopathy may respond favorably to conservative chiropractic treatment and active rehabilitation with minimal time off of training. PMID:22014863

  3. Achilles tendon: US examination

    SciTech Connect

    Fornage, B.D.

    1986-06-01

    Real-time ultrasonography (US) using linear-array probes and a stand-off pad as a ''waterpath'' was performed to evaluate the Achilles tendon in 67 patients (including 24 athletes) believed to have acute or chronic traumatic or inflammatory pathologic conditions. Tendons in 23 patients appeared normal on US scans. The 44 abnormal tendons comprised five complete and four partial ruptures, seven instances of postoperative change, and 28 cases of tendonitis. US depiction of the inner structure of the tendon resulted in the diagnosis of focal abnormalities, including partial ruptures, nodules, and calcifications. Tendonitis was characterized by enlargement and decreased echogenicity of the tendon. The normal US appearance of the Achilles tendon is described.

  4. Biomechanics of Tendon Transfers.

    PubMed

    Livermore, Andrew; Tueting, Jonathan L

    2016-08-01

    The transfer of tendons in the upper extremity is a powerful technique to restore function to a partially paralyzed hand. The biomechanical principles of muscle tension and tendon excursion dictate motor function both in the native as well as transferred states. Appropriately tensioning transferred tendons to maximize the function of the associated muscle remains an area of focused research. Newer methods of tendon coaptation have proven similar in strength to the standard Pulvertaft weave, affording more options to the surgeon. PMID:27387073

  5. Biologics for tendon repair☆

    PubMed Central

    Docheva, Denitsa; Müller, Sebastian A.; Majewski, Martin; Evans, Christopher H.

    2015-01-01

    Tendon injuries are common and present a clinical challenge to orthopedic surgery mainly because these injuries often respond poorly to treatment and require prolonged rehabilitation. Therapeutic options used to repair ruptured tendons have consisted of suture, autografts, allografts, and synthetic prostheses. To date, none of these alternatives has provided a successful long-term solution, and often the restored tendons do not recover their complete strength and functionality. Unfortunately, our understanding of tendon biology lags far behind that of other musculoskeletal tissues, thus impeding the development of new treatment options for tendon conditions. Hence, in this review, after introducing the clinical significance of tendon diseases and the present understanding of tendon biology, we describe and critically assess the current strategies for enhancing tendon repair by biological means. These consist mainly of applying growth factors, stem cells, natural biomaterials and genes, alone or in combination, to the site of tendon damage. A deeper understanding of how tendon tissue and cells operate, combined with practical applications of modern molecular and cellular tools could provide the long awaited breakthrough in designing effective tendon-specific therapeutics and overall improvement of tendon disease management. PMID:25446135

  6. Achilles tendon repair

    MedlinePlus

    ... ency/article/007643.htm Achilles tendon repair To use the sharing features on this page, please enable JavaScript. Your Achilles tendon joins your calf muscle to your heel. You can tear your Achilles tendon if you land hard on your heel during sports, from a ...

  7. Pressurized gas filled tendons

    SciTech Connect

    Silcox, W. H.

    1985-06-04

    Pressurized gas filled tubular tendons provide a means for detecting leaks therein. Filling the tendon with a gaseous fluid provides increased buoyancy and reduces the weight supported by the buoyant structure. The use of a corrosion inhibiting gaseous fluid reduces the corrosion of the interior tendon wall.

  8. [The effect of platelet-rich plasma on graft healing in reconstruction of the anterior cruciate ligament of the knee joint: prospective study].

    PubMed

    Komzák, M; Hart, R; Šmíd, P; Puskeiler, M; Jajtner, P

    2015-01-01

    PURPOSE OF THE STUDY Growth factors produced by platelets enhance tissue healing. The aim of this study was to confirm or disprove the hypothesis that, in anterior cruciate ligament (ACL) reconstruction, the application of platelet-rich plasma (PRP) into the tibial and femoral tunnels and in the graft enhances graft maturation and graft-bone interface healing and thus improves knee function at 3 and 12 months post-operatively in comparison with the control group. MATERIAL AND METHODS A total of 40 patient had the surgery; 20 underwent single-bundle hamstring reconstruction with PRP application (PRP group) and 20 had the same surgery without PRP addition (control group). A 5 ml amount of PRP was obtained from the patient's peripheral blood. A graft inserted in the bone tunnels was fixed with interference screws and, after intra-articular fluid aspiration, 1 ml of PRP was injected into each tunnel and 3 ml were evenly applied to the intra-articular portion of the graft. The patients were examined by MRI at 3 and 12 months after surgery. The subsidence of swelling in the tunnelsurrounding tissues was taken as a sign of graft-bone interface healing, and increased signal intensity of the graft was considered as a result of its ligamentisation. The knee functional status was evaluated at 3 and 12 post-operative months, using the scoring systems (Cincinnati score, IKDC score). RESULTS Bone swelling was found at 3 post-operative months in 18 of 20 patients in both the PRP and the control group. Graft signal intensity was increased in most patients (19 of the PRP group; 18 control patients; p = 0.949). The Cincinnati score at 3 months had an average value of 72.7 (34-100; SO, 18.7) in the PRP group and 73.4 (42-99; SO, 16.3) in the control group (p = 0.793). The functional score after 12 months improved to 97.5 (75-100; SO, 12.8) in the PRP group and to 95.1 (66-100; SO, 13.1) in the control group; there was no significant difference between the groups (p = 0.885) at either

  9. Radial Nerve Tendon Transfers.

    PubMed

    Cheah, Andre Eu-Jin; Etcheson, Jennifer; Yao, Jeffrey

    2016-08-01

    Radial nerve palsy typically occurs as a result of trauma or iatrogenic injury and leads to the loss of wrist extension, finger extension, thumb extension, and a reduction in grip strength. In the absence of nerve recovery, reconstruction of motor function involves tendon transfer surgery. The most common donor tendons include the pronator teres, wrist flexors, and finger flexors. The type of tendon transfer is classified based on the donor for the extensor digitorum communis. Good outcomes have been reported for most methods of radial nerve tendon transfers as is typical for positional tendon transfers not requiring significant power. PMID:27387076

  10. Tendon Structure and Composition.

    PubMed

    Thorpe, Chavaunne T; Screen, Hazel R C

    2016-01-01

    Tendons are soft, fibrous tissues that connect muscle to bone. Their main function is to transfer muscle generated force to the bony skeleton, facilitating movement around a joint, and as such they are relatively passive, inelastic structures, able to resist high forces. Tendons are predominantly composed of collagen, which is arranged in a hierarchical manner parallel to the long axis of the tendon, resulting in high tensile strength. Tendon also contains a range of non-collagenous proteins, present in low amounts, which nevertheless have important functional roles. In this chapter, we describe general tendon composition and structure, and discuss how variations in composition and structure at different levels of the tendon hierarchy confer specific mechanical properties, which are related to tendon function. PMID:27535244

  11. A new strategy for the decellularisation of large equine tendons as biocompatible tendon substitutes.

    PubMed

    Bottagisio, M; Pellegata, A F; Boschetti, F; Ferroni, M; Moretti, M; Lovati, A B

    2016-01-01

    Tendon ruptures and/or large losses remain to be a great clinical challenge and often require full replacement of the damaged tissue. The use of auto- and allografts or engineered scaffolds is an established approach to restore severe tendon injuries. However, these grafts are commonly related to scarce biocompatibility, site morbidity, chronic inflammation and poor biomechanical properties. Recently, the decellularisation techniques of allo- or xenografts using specific detergents have been studied and have been found to generate biocompatible substitutes that resemble the native tissue. This study aims to identify a novel decellularisation protocol for large equine tendons that would produce an extracellular matrix scaffold suitable for the regeneration of injured tendons in humans. Specifically, equine tendons were treated either with tri (n-butyl) phosphate alone, or associated to multiple concentrations of peracetic acid (1, 3 and 5 %), which has never before been tested in vitro.Samples were then analysed by histology and with biochemical, biomechanical, and cytotoxicity tests. The best decellularisation protocol, resulting from these examinations, was selected and the chosen scaffold was re-seeded with murine fibroblasts. Resulting grafts were tested for cell viability, histologic analysis, DNA and collagen content. The results identified 1 % tri (n-butyl) phosphate combined with 3 % peracetic acid as the most suitable decellularised matrix in terms of biochemical and biomechanical properties. Moreover, the non-cytotoxic nature of the decellularised matrix allowed for good fibroblast reseeding, thus demonstrating a biocompatible matrix that will be suitable for tendon tissue engineering and hopefully as substitutes in severe tendon damages. PMID:27386840

  12. Hamstring Fatigue and Muscle Activation Changes During Six Sets of Nordic Hamstring Exercise in Amateur Soccer Players.

    PubMed

    Marshall, Paul W M; Lovell, Ric; Knox, Michael F; Brennan, Scott L; Siegler, Jason C

    2015-11-01

    The Nordic hamstring exercise (NHE) is a bodyweight movement commonly prescribed to increase eccentric hamstring strength and reduce the incidence of strain injury in sport. This study examined hamstring fatigue and muscle activation responses throughout 6 sets of 5 repetitions of the NHE. Ten amateur-level soccer players performed a single session of 6 sets of 5 repetitions of NHE. Maximal eccentric and concentric torque output (in newton meters) was measured after every set. Hamstrings electromyograms (EMG) were measured during all maximal contractions and exercise repetitions. Hamstring maximal eccentric torque was reduced throughout the range of motion after only a single set of NHE between 7.9 and 17.1% (p ≤ 0.05), with further reductions in subsequent sets. Similarly, maximal concentric torque reductions between 7.8 and 17.2% were observed throughout the range of motion after 1 set of NHE (p ≤ 0.05). During the descent phase of the NHE repetitions, hamstring muscle activity progressively increased as the number of sets performed increased. These increases were observed in the first half of the range of motion. During the ascent phase, biceps femoris muscle activity but not medial hamstrings was reduced from the start of exercise during latter sets of repetitions. These data provide unique insight into the extent of fatigue induced from a bodyweight only exercise after a single set of 5 repetitions. Strength and conditioning coaches need to be aware of the speed and extent of fatigue induced from NHE, particularly in practical settings in which this exercise is now prescribed before sport-specific training sessions (i.e., the FIFA-11 before soccer training). PMID:25886019

  13. Concentric Versus Enhanced Eccentric Hamstring Strength Training: Clinical Implications

    PubMed Central

    Kaminski, Thomas W.; Wabbersen, Chuck V.; Murphy, Robert M.

    1998-01-01

    Objective: Hamstring injuries can be quite debilitating and often result in chronic problems. Eccentric muscle actions are often the last line of defense against muscle injury and ligament disruption. Traditionally, the focus of hamstring strength rehabilitation has been on concentric muscle actions. The purpose of our study was to compare hamstring muscle strength gains in concentric and eccentric hamstring strength training. Design and Setting: A randomized-group design was used to examine differences in 1-repetition maximum (1 RM) and isokinetic strength values among 3 groups of subjects. Subjects were tested in a biomechanics laboratory using an isokinetic dynamometer, while training was carried out in a physical therapy outpatient clinic. Subjects: Twenty-seven healthy male subjects (age = 22.9 ± 3.1 years, wt = 81.8 ± 12.9 kg, ht = 178.6 ± 7.2 cm) participated in this study. Subjects were randomly assigned to 1 of 3 treatment groups: eccentric training, concentric training, or control. Measurements: Subjects performed hamstring curls using an isotonic weight training device. Pretest 1 RM weight values were determined for all subjects using a standardized 1 RM protocol. In addition, maximum concentric and eccentric isokinetic strength values for knee-flexion strength were determined. Control group subjects refrained from weight training for 6 weeks. Subjects in the training groups trained 2 days per week for 6 weeks (12 sessions). After 6 weeks of training, all subjects returned for 1RM and isokinetic posttesting. Results: The concentric group improved 19%, while the eccentric group improved 29%. The control group subjects did not show any significant change over the 6 weeks. In addition, there were improvements in eccentric isokinetic peak torque/ body weight ratios at both 60 °s and 180° from pretesting to posttesting in the eccentric training group only. Conclusions: Our results demonstrate the effectiveness of isotonic strength training on the

  14. Effects of Trypsinization and Mineralization on Intrasynovial Tendon Allograft Healing to Bone

    PubMed Central

    Qu, Jin; van Alphen, Nick A.; Thoreson, Andrew R.; Chen, Qingshan; An, Kai-Nan; Amadio, Peter C.; Schmid, Thomas M.; Zhao, Chunfeng

    2014-01-01

    The purpose of the current study was to develop a novel technology to enhance tendon-to-bone interface healing by trypsinizing and mineralizing (TM) an intrasynovial tendon allograft in a rabbit bone tunnel model. Eight rabbit flexor digitorum profundus (FDP) tendons were used to optimize the trypsinization process. An additional 24 FDP tendons were stratified into control and TM groups; in each group, 4 tendons were used for in vitro evaluation of TM and 8 were transplanted into proximal tibial bone tunnels in rabbits. The samples were evaluated histologically and with mechanical testing at postoperative week 8. Maximum failure strength and linear stiffness were not significantly different between the control and TM tendons. A thin fibrous band of scar tissue formed at the graft-to-bone interface in the control group. However, only the TM group showed obvious new bone formation inside the tendon graft and a visible fibrocartilage layer at the bone tunnel entrance. This study is the first to explore effects of TM on the intrasynovial allograft healing to a bone tunnel. TM showed beneficial effects on chondrogenesis, osteogenesis, and integration of the intrasynovial tendon graft, but mechanical strength was the same as the control tendons in this short-term in vivo study. PMID:25611186

  15. Changes in hip joint muscle-tendon lengths with mode of locomotion.

    PubMed

    Riley, Patrick O; Franz, Jason; Dicharry, Jay; Kerrigan, D Casey

    2010-02-01

    We have reported that peak hip extension is nearly identical in walking and running, suggesting that anatomical constraints, such as flexor muscle tightness may limit the range of hip extension. To obtain a more mechanistic insight into mobility at the hip and pelvis we examined the lengths of the muscle-tendons units crossing the hip joint. Data defining the three-dimensional kinematics of 26 healthy runners at self-selected walking and running speeds were obtained. These data were used to scale and drive musculoskeletal models using OpenSIM. Muscle-tendon unit (MTU) lengths were calculated for the trailing limb illiacus, rectus femoris, gluteus maximus, and biceps femoris long head and the advancing limb biceps femoris and gluteus maximus. The magnitude and timing of MTU length peaks were each compared between walking and running. The peak length of the right (trailing limb) illiacus MTU, a pure hip flexor, was nearly identical between walking and running, while the maximum length of the rectus femoris MTU, a hip flexor and knee extensor, increased during running. The maximum length of the left (leading limb) biceps femoris was also unchanged between walking and running. Further, the timing of peak illiacus MTU length and peak contralateral biceps femoris MTU length occurred essentially simultaneously during running, at a time during gait when the hamstrings are most vulnerable to stretch injury. This latter finding suggests exploring the role for hip flexor stretching in combination with hamstring stretching to treat and/or prevent running related hamstring injury. PMID:20022251

  16. Effects of lubricant and autologous bone marrow stromal cell augmentation on immobilized flexor tendon repairs.

    PubMed

    Zhao, Chunfeng; Ozasa, Yasuhiro; Shimura, Haruhiko; Reisdorf, Ramona L; Thoreson, Andrew R; Jay, Gregory; Moran, Steven L; An, Kai-Nan; Amadio, Peter C

    2016-01-01

    The purpose of the study was to test a novel treatment that carbodiimide-derivatized-hyaluronic acid-lubricin (cd-HA-lubricin) combined cell-based therapy in an immobilized flexor tendon repair in a canine model. Seventy-eight flexor tendons from 39 dogs were transected. One tendon was treated with cd-HA-lubricin plus an interpositional graft of 8 × 10(5) BMSCs and GDF-5. The other tendon was repaired without treatment. After 21 day of immobilization, 19 dogs were sacrificed; the remaining 20 dogs underwent a 21-day rehabilitation protocol before euthanasia. The work of flexion, tendon gliding resistance, and adhesion score in treated tendons were significantly less than the untreated tendons (p < 0.05). The failure strength of the untreated tendons was higher than the treated tendons at 21 and 42 days (p < 0.05). However, there is no significant difference in stiffness between two groups at day 42. Histologic analysis of treated tendons showed a smooth surface and viable transplanted cells 42 days after the repair, whereas untreated tendons showed severe adhesion formation around the repair site. The combination of lubricant and cell treatment resulted in significantly improved digit function, reduced adhesion formation. This novel treatment can address the unmet needs of patients who are unable to commence an early mobilization protocol after flexor tendon repair. PMID:26177854

  17. Tendon Functional Extracellular Matrix

    PubMed Central

    Screen, H.R.C.; Birk, D.E.; Kadler, K.E.; Ramirez, F; Young, M.F.

    2015-01-01

    This article is one of a series, summarising views expressed at the Orthopaedic Research Society New Frontiers in Tendon Research Conference. This particular article reviews the three workshops held under the “Functional Extracellular Matrix” stream. The workshops focused on the roles of the tendon extracellular matrix, such as performing the mechanical functions of tendon, creating the local cell environment and providing cellular cues. Tendon is a complex network of matrix and cells, and its biological functions are influenced by widely-varying extrinsic and intrinsic factors such as age, nutrition, exercise levels and biomechanics. Consequently, tendon adapts dynamically during development, ageing and injury. The workshop discussions identified research directions associated with understanding cell-matrix interactions to be of prime importance for developing novel strategies to target tendon healing or repair. PMID:25640030

  18. Surgical Management of Recurrent Musculotendinous Hamstring Injury in Professional Athletes

    PubMed Central

    Sonnery-Cottet, Bertrand; Daggett, Matt; Gardon, Roland; Pupim, Barbara; Clechet, Julien; Thaunat, Mathieu

    2015-01-01

    Background: Hamstring injury is the most common muscular lesion in athletes. The conservative treatment is well described, and surgical management is often indicated for proximal tendinous avulsions. To our knowledge, no surgical treatment has been proposed for failure of conservative treatment in musculotendinous hamstring lesions. Purpose: To describe the surgical management of proximal and distal hamstring musculotendinous junction lesions in professional athletes after failure of conservative treatment. Study Design: Case series; Level of evidence, 4. Methods: A consecutive series of 10 professional athletes, including 4 soccer players, 4 rugby players, and 2 handball players, underwent surgical intervention between October 2010 and June 2014 for the treatment of recurrent musculotendinous hamstring injuries. All athletes had failed at least 3 months of conservative treatment for a recurrent musculotendinous hamstring injury. Surgical resection of the musculotendinous scar tissue was performed using a longitudinal muscular suture. Lower Extremity Functional Scale (LEFS) and Marx scores were obtained at the 3-month follow-up, and a final phone interview was completed to determine recurrence of hamstring injury and return to previous level of play. Results: The mean age at surgery was 25.2 years (range, 19-35 years). The musculotendinous hamstring lesions involved 8 semitendinosus and 2 biceps femoris, with 6 injuries located proximally and 4 distally. Conservative treatment lasted a mean 5.1 months (range, 3-9 months) after last recurrence, and the patients had an average of 2.7 (range, 2-5) separate incidents of injury recurrence before surgical intervention was decided upon. At the 3-month follow-up, all patients had Marx activity scores of 16 and LEFS scores of 80. All 10 patients returned to the same level of play at a mean 3.4 months (range, 2-5 months). At a mean follow-up of 28.7 months, none of the athletes had suffered a recurrence. No surgical

  19. Principles of Tendon Transfer.

    PubMed

    Wilbur, Danielle; Hammert, Warren C

    2016-08-01

    Tendon transfers provide a substitute, either temporary or permanent, when function is lost due to neurologic injury in stroke, cerebral palsy or central nervous system lesions, peripheral nerve injuries, or injuries to the musculotendinous unit itself. This article reviews the basic principles of tendon transfer, which are important when planning surgery and essential for an optimal outcome. In addition, concepts for coapting the tendons during surgery and general principles to be followed during the rehabilitation process are discussed. PMID:27387072

  20. Use of the semitendinosus tendon for foot and ankle tendon reconstructions☆☆☆

    PubMed Central

    Lutti Guerra de Aguiar Zink, Frederico; Glória Mendonça, Danilo; Kelly Bittar, Cintia; Luís Amim Zabeu, José; Salomão, Osny; Egydio de Carvalho Junior, Antonio; Tarso Torquato, Marcelo; Cerqueira de Moraes Filho, Décio

    2014-01-01

    Objective To demonstrate the results obtained from foot and ankle tendon reconstructions using the tendon of the semitendinosus muscle. The clinical results, the patient's degree of satisfaction and complications in the graft donor and recipient areas were evaluated. Methods This was a retrospective study in which the medical files of 38 patients who underwent this surgical procedure between 2006 and 2010 were surveyed. The functional results from this technique, the complications in the donor and recipient areas and the patients’ degree of satisfaction were evaluated. Results Three patients presented complications in the recipient area (skin necrosis); one patient showed complications in the donor area (pain and insensitivity); and all patients had satisfactory functional results, with complete range of motion. Conclusion The semitendinosus muscle is a good option for treatments for foot and ankle tendon injuries. PMID:26229856

  1. Tendon and ligament imaging

    PubMed Central

    Hodgson, R J; O'Connor, P J; Grainger, A J

    2012-01-01

    MRI and ultrasound are now widely used for the assessment of tendon and ligament abnormalities. Healthy tendons and ligaments contain high levels of collagen with a structured orientation, which gives rise to their characteristic normal imaging appearances as well as causing particular imaging artefacts. Changes to ligaments and tendons as a result of disease and injury can be demonstrated using both ultrasound and MRI. These have been validated against surgical and histological findings. Novel imaging techniques are being developed that may improve the ability of MRI and ultrasound to assess tendon and ligament disease. PMID:22553301

  2. Riser and tendon management system

    SciTech Connect

    Devlin, P.V.

    1992-02-18

    This patent describes a riser and tendon management system. It comprises means to set nominal conditions for the risers and tendons; means to measure actual riser and tendon conditions; means to compare the actual and nominal conditions of the risers and tendons; and means responsive to a differential between the actual and nominal riser and tendon conditions, which difference exceeds specified limits, and recommending corrective action to bring the risers and tendons back to within nominal conditions.

  3. Biomechanical evaluation of acellular collagen matrix augmented Achilles tendon repair in sheep.

    PubMed

    Song, Lin; Olsen, Raymond E; Spalazzi, Jeffrey P; Davisson, Twana

    2010-01-01

    The rate of rerupture of repaired Achilles tendon in young and athletic populations remains high despite improvement in surgical techniques, suture design, and postsurgical management. Acellular biological matrices can be used to enhance the immediate strength of repaired tendons and to serve as scaffolds for cell in-growth and constructive tissue remodeling. A number of commercially available matrices have been used clinically, albeit with varying degrees of success and failure. The disparity is likely attributable to the different physical and biochemical properties of individual matrices. In this study, we investigated the biomechanical characteristics of 2 different acellular collagen matrices, namely TissueMend and GraftJacket, using a sheep Achilles tendon repair model. Static and cyclic creep, cyclic and linear construct stiffness, maximum load to failure, and displacement at maximum load were determined at time zero. We found that the maximum load to failure, displacement, and ultimate failure mode were similar between tendons augmented with either acellular collagen matrix; however, TissueMend augmentation yielded lower creep and smaller construct elongation than did GraftJacket. The results indicated that the strength of TissueMend-augmented tendons and GraftJacket-augmented tendons was not statistically significantly different, although tendons augmented with TissueMend displayed greater stiffness, which may be clinically advantageous in the restoration of ruptured tendons. PMID:20797586

  4. Influence of Passive Stiffness of Hamstrings on Postural Stability

    PubMed Central

    Kuszewski, Michał; Gnat, Rafał; Sobota, Grzegorz; Myśliwiec, Andrzej

    2015-01-01

    The aim of the study was to explore whether passive stiffness of the hamstrings influences the strategy of maintaining postural stability. A sample of 50 subjects was selected; the final analyses were based on data of 41 individuals (33 men, 8 women) aged 21 to 29 (mean = 23.3, SD = 1.1) years. A quasi- experimental ex post facto design with repeated measures was used. Categories of independent variables were obtained directly prior to the measurement of the dependent variables. In stage one of the study, passive knee extension was measured in the supine position to assess hamstring stiffness. In stage two, the magnitude of postural sway in antero-posterior direction was measured, while varying the body position on a stabilometric platform, both with and without visual control. The margin of safety was used as a measure of postural control. The magnitude of the margin of safety increased significantly between the open-eye and closed-eye trials. However, although we registered a visible tendency for a larger increase of the margin of safety associated with lower levels of passive hamstrings stiffness, no significant differences were found. Therefore, this study demonstrated that hamstring stiffness did not influence the strategy used to maintain postural stability. PMID:25964809

  5. Fatigue loading of tendon

    PubMed Central

    Shepherd, Jennifer H; Screen, Hazel R C

    2013-01-01

    Tendon injuries, often called tendinopathies, are debilitating and painful conditions, generally considered to develop as a result of tendon overuse. The aetiology of tendinopathy remains poorly understood, and whilst tendon biopsies have provided some information concerning tendon appearance in late-stage disease, there is still little information concerning the mechanical and cellular events associated with disease initiation and progression. Investigating this in situ is challenging, and numerous models have been developed to investigate how overuse may generate tendon fatigue damage and how this may relate to tendinopathy conditions. This article aims to review these models and our current understanding of tendon fatigue damage. We review the strengths and limitations of different methodologies for characterizing tendon fatigue, considering in vitro methods that adopt both viable and non-viable samples, as well as the range of different in vivo approaches. By comparing data across model systems, we review the current understanding of fatigue damage development. Additionally, we compare these findings with data from tendinopathic tissue biopsies to provide some insights into how these models may relate to the aetiology of tendinopathy. Fatigue-induced damage consistently highlights the same microstructural, biological and mechanical changes to the tendon across all model systems and also correlates well with the findings from tendinopathic biopsy tissue. The multiple testing routes support matrix damage as an important contributor to tendinopathic conditions, but cellular responses to fatigue appear complex and often contradictory. PMID:23837793

  6. Peroneal Tendon Injuries

    MedlinePlus

    ... ACFAS | Información en Español Advanced Search Home » Foot & Ankle Conditions » Peroneal Tendon Injuries Text Size Print Bookmark ... foot run side-by-side behind the outer ankle bone. One peroneal tendon attaches to the outer ...

  7. Tendon Transfers for Tetraplegia.

    PubMed

    Bednar, Michael S

    2016-08-01

    It is estimated that 65% to 75% of patients with cervical spinal cord injuries could benefit from upper extremity tendon transfer surgery. The goals of surgery are to restore elbow extension, as well as hand pinch, grasp, and release. Patients who have defined goals, actively participate in therapy, and understand expected outcomes, appear to have the highest satisfaction following tendon transfer procedures. PMID:27387082

  8. Patellar tendon rerupture in a footballer: our personal surgical technique and review of the literature.

    PubMed

    Moretti, L; Vicenti, G; Abate, A; Pesce, V; Moretti, B

    2014-02-01

    Patellar tendon rerupture is a relatively uncommon condition that severely compromises the function of the extensor mechanism of the knee. Few cases described in the literature does not show a unique mode of treatment for this type of lesion. We report the case of a young athlete with traumatic patellar tendon rerupture. The first rupture was treated with the use of Statak anchors. Following a second rerupture incident as a result of a sporting accodent, the tendon was reconstructed with the use of an autologous graft tendon of semitendinosus and biological augmentation with gracilis tendon. For both tendons the distal insertion part was preserved to facilitate the healing process. The treatment was completed with the application of a neutralization cerclage wire and with local injection of plateket reach plasma (PRP). At 12 months follow up, a full recovery of the structure and function of the extensor mechanism was observed and the patient was able to resume normal sports competitive activity. PMID:24314874

  9. Skin graft

    MedlinePlus

    Skin transplant; Skin autografting; FTSG; STSG; Split thickness skin graft; Full thickness skin graft ... site. Most people who are having a skin graft have a split-thickness skin graft. This takes ...

  10. How Obesity Affects Tendons?

    PubMed

    Abate, Michele; Salini, Vincenzo; Andia, Isabel

    2016-01-01

    Several epidemiological and clinical observations have definitely demonstrated that obesity has harmful effects on tendons. The pathogenesis of tendon damage is multi-factorial. In addition to overload, attributable to the increased body weight, which significantly affects load-bearing tendons, systemic factors play a relevant role. Several bioactive peptides (chemerin, leptin, adiponectin and others) are released by adipocytes, and influence tendon structure by means of negative activities on mesenchymal cells. The ensuing systemic state of chronic, sub-clinic, low-grade inflammation can damage tendon structure. Metabolic disorders (diabetes, impaired glucose tolerance, and dislipidemia), frequently associated with visceral adiposity, are concurrent pathogenetic factors. Indeed, high glucose levels increase the formation of Advanced Glycation End-products, which in turn form stable covalent cross-links within collagen fibers, modifying their structure and functionality.Sport activities, so useful for preventing important cardiovascular complications, may be detrimental for tendons if they are submitted to intense acute or chronic overload. Therefore, two caution rules are mandatory: first, to engage in personalized soft training program, and secondly to follow regular check-up for tendon pathology. PMID:27535258

  11. [Reinforcement of freshly glued or sutured rupture of the anterior cruciate ligament using the semitendinous tendon. Indications and early results].

    PubMed

    Paar, O

    1985-11-01

    Inopportune rupture forms deteriorate the prognosis after reconstructive operations on the anterior cruciate ligament. In order to improve the treatment results, we apply fibrin glue on intraligamentous ruptures and reinforce the reconstruction result with a distally fixed semitendinosus tendon graft. In old ruptures with beginning degenerative changes on the rupture stumps we refix the rest of the cruciate ligament as a posterolateral ligament part through transosseous sutures and also use the semitendinosus tendon as a reinforcement graft. 19 of the 26 cruciate ligaments treated in this way were stable at the reexamination which took place 9 months after the operation on a average. 7 remaining instabilities are due to degenerative changes of both the tendon graft and the reconstructed rests of the cruciate ligaments: this could be proved by CT-studies. Using a tendon graft in combination with alloplastic materials ought to improve the postoperative results in future. PMID:3908015

  12. Augmentation of tendon attachment to porous ceramics by bone marrow stromal cells in a rabbit model

    PubMed Central

    Mochizuki, Yu; Yokoya, Shin; Adachi, Nobuo; Ochi, Mitsuo

    2006-01-01

    Tendon attachment to interconnected porous calcium hydroxyapatite ceramics (IP-CHA) with cultured bone marrow stromal cells (BMSC) was analysed. The purpose of this study was to evaluate whether BMSC in IP-CHA could augment the tendon attachment to IP-CHA histologically and biomechanically. Eighteen Japanese white rabbits were used. Cultured BMSCs were subcultured in IP-CHA. The grafted tendon and IP-CHA with BMSC complex were implanted in a bone defect of the knee [BMSC(+) group]. In the contralateral knee, a tendon and IP-CHA without BMSC complex were implanted [BMSC(-) group]. Histological findings of the interface between the tendon and IP-CHA were similar in the two groups 3 weeks after the operation. However, 6 weeks after the operation, more abundant bone formation around the tendon was observed in the BMSC(+) group. The direct apposition of the tendon to bone in pores and collagen fibre continuity between the tendon and fibrous tissue in pores were observed. In biomechanical evaluation, the maximum pull-out load of the tendon from the IP-CHA in the BMSC(+) group was significantly higher than that in the BMSC(-) group 6 weeks after the operation. BMSCs cultured in IP-CHA could augment tendon attachment to IP-CHA. PMID:16909253

  13. Achilles Tendon Disorders

    MedlinePlus

    ... after periods of rest, then improves somewhat with motion but later worsens with increased activity. Tenderness, or ... foot and ankle and evaluate the range of motion and condition of the tendon. The extent of ...

  14. Inflamed shoulder tendons (image)

    MedlinePlus

    Tearing and inflammation of the tendons of the shoulder muscles can occur in sports which require the ... pitching, swimming, and lifting weights. Most often the shoulder will heal if a break is taken from ...

  15. Subrupture Tendon Fatigue Damage

    PubMed Central

    Laudier, Damien M.; Shine, Jean H.; Basta-Pljakic, Jelena; Jepsen, Karl J.; Schaffler, Mitchell B.; Flatow, Evan L.

    2016-01-01

    The mechanical and microstructural bases of tendon fatigue, by which damage accumulates and contributes to degradation, are poorly understood. To investigate the tendon fatigue process, rat flexor digitorum longus tendons were cyclically loaded (1–16 N) until reaching one of three levels of fatigue damage, defined as peak clamp-to-clamp strain magnitudes representing key intervals in the fatigue life: i) Low (6.0%–7.0%); ii) Moderate (8.5%–9.5%); and iii) High (11.0%–12.0%). Stiffness, hysteresis, and clamp-to-clamp strain were assessed diagnostically (by cyclic loading at 1–8 N) before and after fatigue loading and following an unloaded recovery period to identify mechanical parameters as measures of damage. Results showed that tendon clamp-to-clamp strain increased from pre- to post-fatigue loading significantly and progressively with the fatigue damage level (p≤0.010). In contrast, changes in both stiffness and hysteresis were significant only at the High fatigue level (p≤0.043). Correlative microstructural analyses showed that Low level of fatigue was characterized by isolated, transverse patterns of kinked fiber deformations. At higher fatigue levels, tendons exhibited fiber dissociation and localized ruptures of the fibers. Histomorphometric analysis showed that damage area fraction increased significantly with fatigue level (p≤0.048). The current findings characterized the sequential, microstructural events that underlie the tendon fatigue process and indicate that tendon deformation can be used to accurately assess the progression of damage accumulation in tendons. PMID:18683881

  16. Hamstring Injuries in Major and Minor League Baseball

    PubMed Central

    Zachazewski, James; Silvers, Holly J.; Li, Bernard; Snyder-Mackler, Lynn; Insler, Stephanie; Ahmad, Christopher S.; Mandelbaum, Bert R.

    2016-01-01

    Objectives: The purpose of this study is to test the efficacy of a hamstring injury prevention program designed to address the high incidence of acute and chronic hamstring injuries and re-injuries that occur in the sport of professional baseball. Methods: This was a prospective cluster cohort study assessing the efficacy of an injury prevention intervention designed to address hamstring injury in rookie and professional baseball players participating in Minor and Major League Baseball (N = 213). Each athlete was asked to participate and consented (Johns Hopkins Internal Review Board, Baltimore, Maryland). Those athletes who agreed to participate completed a questionnaire detailing their hamstring injury history. The hamstring injury prevention program was disseminated to each medical staff (team physician, certified athletic trainer and strength and conditioning coach) and they were instructed on how to implement the program. Weekly individual compliance with the program and injury data was collected. At the end of the season, the data were analyzed for program compliance and hamstring (HS) injury rates (both acute and reoccurrence) compared to the control data in the MLB HITS database. All data were stripped of individual and team identifiers prior to analysis. Results: For the major and minor league intervention study, one Major and Minor League organization served as the intervention (INT) team, which encompassed Rookie League, Fall Ball, Class A, AA, AAA and major league rosters (6 total teams). A total of 213 athletes consented to participate: Minor League: N = 173 players and Majors League: N = 40. Weekly compliance, injury incidence and time loss due to injury was compared to the HITS database (age, skill matched control group). The average weighted utilization of the injury prevention program was 25.30 utilizations for the uninjured group compared to 13.53 in the injured group (p=0.09). In the majors, there were 2 HS injuries in the INT vs. 79 in the CON

  17. Proximal Hamstring Tendinopathy: Clinical Aspects of Assessment and Management.

    PubMed

    Goom, Thomas S H; Malliaras, Peter; Reiman, Michael P; Purdam, Craig R

    2016-06-01

    Synopsis Proximal hamstring tendinopathy (PHT) typically manifests as deep buttock pain at the hamstring common origin. Both athletic and nonathletic populations are affected by PHT. Pain and dysfunction are often long-standing and limit sporting and daily functions. There is limited evidence regarding diagnosis, assessment, and management; for example, there are no randomized controlled trials investigating rehabilitation of PHT. Some of the principles of management established in, for example, Achilles and patellar tendinopathy would appear to apply to PHT but are not as well documented. This narrative review and commentary will highlight clinical aspects of assessment and management of PHT, drawing on the available evidence and current principles of managing painful tendinopathy. The management outline presented aims to guide clinicians as well as future research. J Orthop Sports Phys Ther 2016;46(6):483-493. Epub 15 Apr 2016. doi:10.2519/jospt.2016.5986. PMID:27084841

  18. The Foam Roll as a Tool to Improve Hamstring Flexibility.

    PubMed

    Junker, Daniel H; Stöggl, Thomas L

    2015-12-01

    Although foam rolling is a common myofascial therapy used to increase range of motion (ROM), research is limited on the effectiveness of foam rolling on soft tissue extensibility. The aim of this study was to determine the effect of a 4-week training period of the foam roll method on hamstring flexibility. Furthermore, the study was designed to compare the effectiveness of the foam roll myofascial release with a conventional contract-relax proprioceptive neuromuscular facilitation (PNF) stretching method and a control group. Forty healthy males (age: 17-47 years) were randomly assigned to a foam roll group (FOAM, n = 13), a contract-relax PNF stretching group (CRPNF, n = 14), or a control group (CG, n = 13). The FOAM group massaged their hamstring muscles with the foam roll 3 times per week for 4 weeks (12 training sessions). The CRPNF group was assigned to 12 sessions of contract-relax PNF stretching. The CG underwent no intervention. Hamstring flexibility (ROM) was measured by a stand-and-reach test before and after the intervention period. Two-way repeated-measures analysis of variance showed a significant global time effect (p < 0.001) and an interaction effect for time × treatment (p = 0.004), demonstrating greater improvements in the FOAM and CRPNF compared with the CG, but no difference between the former. Delta changes from baseline to postintervention in ROM were not related to baseline ROM. The foam roll can be seen as an effective tool to increase hamstring flexibility within 4 weeks. The effects are comparable with the scientifically proven contract-relax PNF stretching method. PMID:25992660

  19. Hamstring Strain Injuries: Recommendations for Diagnosis, Rehabilitation and Injury Prevention

    PubMed Central

    Heiderscheit, Bryan C.; Sherry, Marc A.; Silder, Amy; Chumanov, Elizabeth S.; Thelen, Darryl G.

    2010-01-01

    Synopsis Hamstring strain injuries remain a challenge for both athletes and clinicians given the high incidence rate, slow healing, and persistent symptoms. Moreover, nearly one-third of these injuries recur within the first year following a return to sport, with subsequent injuries often being more severe than the original. This high reinjury rate suggests that commonly utilized rehabilitation programs may be inadequate at resolving possible muscular weakness, reduced tissue extensibility, and/or altered movement patterns associated with the injury. Further, the traditional criteria used to determine the readiness of the athlete to return to sport may be insensitive to these persistent deficits, resulting in a premature return. There is mounting evidence that the risk of reinjury can be minimized by utilizing rehabilitation strategies that incorporate neuromuscular control exercises and eccentric strength training, combined with objective measures to assess musculotendon recovery and readiness to return to sport. In this paper, we first describe the diagnostic examination of an acute hamstring strain injury, including discussion of the value of determining injury location in estimating the duration of the convalescent period. Based on the current available evidence, we then propose a clinical guide for the rehabilitation of acute hamstring injuries including specific criteria for treatment progression and return to sport. Finally, we describe directions for future research including injury-specific rehabilitation programs, objective measures to assess reinjury risk, and strategies to prevent injury occurrence. Level of evidence: Diagnosis/therapy, level 5. PMID:20118524

  20. Strength Measurements in Acute Hamstring Injuries: Intertester Reliability and Prognostic Value of Handheld Dynamometry.

    PubMed

    Reurink, Gustaaf; Goudswaard, Gert Jan; Moen, Maarten H; Tol, Johannes L; Verhaar, Jan A N; Weir, Adam

    2016-08-01

    Study Design Cohort study, repeated measures. Background Although hamstring strength measurements are used for assessing prognosis and monitoring recovery after hamstring injury, their actual clinical relevance has not been established. Handheld dynamometry (HHD) is a commonly used method of measuring muscle strength. The reliability of HHD has not been determined in athletes with acute hamstring injuries. Objectives To determine the intertester reliability and the prognostic value of hamstring HHD strength measurement in acute hamstring injuries. Methods We measured knee flexion strength with HHD in 75 athletes at 2 visits, at baseline (within 5 days of hamstring injury) and follow-up (5 to 7 days after the baseline measurement). We assessed isometric hamstring strength in 15° and 90° of knee flexion. Reliability analysis testing was performed by 2 testers independently at the follow-up visit. We recorded the time needed to return to play (RTP) up to 6 months following baseline. Results The intraclass correlation coefficients of the strength measurements in injured hamstrings were between 0.75 and 0.83. There was a statistically significant but weak correlation between the time to RTP and the strength deficit at 15° of knee flexion measured at baseline (Spearman r = 0.25, P = .045) and at the follow-up visit (Spearman r = 0.26, P = .034). Up to 7% of the variance in time to RTP is explained by this strength deficit. None of the other strength variables were significantly correlated with time to RTP. Conclusion Hamstring strength can be reliably measured with HHD in athletes with acute hamstring injuries. The prognostic value of strength measurements is limited, as there is only a weak association between the time to RTP and hamstring strength deficit after acute injury. Level of Evidence Prognosis, level 4. J Orthop Sports Phys Ther 2016;46(8):689-696. Epub 12 May 2016. doi:10.2519/jospt.2016.6363. PMID:27170527

  1. Tendon Reconstruction with Tissue Engineering Approach--A Review.

    PubMed

    Verdiyeva, Gunay; Koshy, Kiron; Glibbery, Natalia; Mann, Haroon; Seifalian, Alexander M

    2015-09-01

    Tendon injuries are a common and rising occurrence, associated with significant impairment to quality of life and financial burden to the healthcare system. Clinically, they represent an unresolved problem, due to poor natural tendon healing and the inability of current treatment strategies to restore the tendon to its native state. Tissue engineering offers a promising alternative, with the incorporation of scaffolds, cells and growth factors to support the complete regeneration of the tendon. The materials used in tendon engineering to date have provided significant advances in structural integrity and biological compatibility and in many cases the results obtained are superior to those observed in natural healing. However, grafts fail to reproduce the qualities of the pre-injured tendon and each has weaknesses subject to its constituent parts. Furthermore, many materials and cell types are being investigated concurrently, with seemingly little association or comparison between research results. In this review the properties of the most-investigated and effective components have been appraised in light of the surrounding literature, with research from early in-vitro experiments to clinical trials being discussed. Extensive comparisons have been made between scaffolds, cell types and growth factors used, listing strengths and weaknesses to provide a stable platform for future research. Promising future endeavours are also described in the field of nanocomposite material science, stem cell sources and growth factors, which may bypass weaknesses found in individual elements. The future of tendon engineering looks bright, with growing understanding in material technology, cell and growth factor application and encouraging recent advances bringing us ever closer to regenerating the native tendon. PMID:26485923

  2. Hyperuricemia in Tendons.

    PubMed

    Andia, Isabel; Abate, Michele

    2016-01-01

    Hyperuricemia, particularly gout, and the immune inflammatory response are highly integrated. Both, long standing hyperuricemia and monosodium urate (MSU) crystal deposition can challenge tendon homeostasis because of their potential to cause inflammation to the host. Knowledge is emerging from clinical imaging research depicting where MSU crystals deposit, including patellar tendon, triceps and quadriceps tendons. Remarkably, subclinical tendon inflammation and damage are also present in asymptomatic hyperuricemia. Monosodium urate crystals act as danger activating molecular patterns (DAMPs), activating the inflammasome and inducing the secretion of IL-1beta, a key mediator of the inflammatory response. The crucial role of IL-1beta in driving the inflammatory events during gout attacks is supported by the clinical efficacy of IL-1beta blockade. Some data implicating IL-1beta as an initiator of tendinopathy exist, but the link between hyperuricemia and the development of tendinopathy remains to be validated. Further knowledge about the interactions of uric acid with both innate immune and tendon cells, and their consequences may help to determine if there is a subclass of hyperuricemic-tendinopathy. PMID:27535254

  3. In vitro effects of glutamate and N-methyl-D-aspartate receptor (NMDAR) antagonism on human tendon derived cells.

    PubMed

    Dean, Benjamin John Floyd; Snelling, Sarah J B; Dakin, Stephanie Georgina; Javaid, Muhammad Kassim; Carr, Andrew Jonathan

    2015-10-01

    It is known that extracellular glutamate concentrations are increased in tendinopathy but the effects of glutamate upon human tendon derived cells are unknown. The primary purpose was to investigate the effect of glutamate exposure on human tendon-derived cells in terms of viability, protein, and gene expression. The second purpose was to assess whether NMDAR antagonism would affect the response of tendon-derived cells to glutamate exposure. Human tendon-derived cells were obtained from supraspinatus tendon tissue obtained during rotator cuff repair (tendon tear derived cells) and from healthy hamstring tendon tissue (control cells). The in vitro impact of glutamate exposure and NMDAR antagonism (MK-801) was measured using the Alamar blue cell viability assay, immunocytochemistry, and quantitative real-time PCR. Glutamate reduced cell viability at 24 h in tendon tear derived cells but not in control cells at concentrations of 7.5 mM and above. Cell viability was significantly reduced after 72 h of 1.875 mM glutamate in both cell groups; this deleterious effect was attenuated by NMDAR antagonism with 10 µM MK-801. Both 24 and 72 h of 1.875 mM glutamate exposure reduced Type 1 alpha 1 collagen (COL1A1) and Type 3 alpha 1 collagen (COL3A1) gene expression, but increased Aggrecan gene expression. We propose that these effects of glutamate on tendon derived cells including reduced cell viability and altered matrix gene expression contribute to the pathogenesis of tendinopathy. PMID:26041147

  4. Tendon Driven Finger Actuation System

    NASA Technical Reports Server (NTRS)

    Ihrke, Chris A. (Inventor); Reich, David M. (Inventor); Bridgwater, Lyndon (Inventor); Linn, Douglas Martin (Inventor); Askew, Scott R. (Inventor); Diftler, Myron A. (Inventor); Platt, Robert (Inventor); Hargrave, Brian (Inventor); Valvo, Michael C. (Inventor); Abdallah, Muhammad E. (Inventor); Permenter, Frank Noble (Inventor); Mehling, Joshua S. (Inventor)

    2013-01-01

    A humanoid robot includes a robotic hand having at least one finger. An actuation system for the robotic finger includes an actuator assembly which is supported by the robot and is spaced apart from the finger. A tendon extends from the actuator assembly to the at least one finger and ends in a tendon terminator. The actuator assembly is operable to actuate the tendon to move the tendon terminator and, thus, the finger.

  5. Bone Grafts

    MedlinePlus

    A bone graft transplants bone tissue. Surgeons use bone grafts to repair and rebuild diseased bones in your hips, knees, spine, and sometimes other bones and joints. Grafts can also repair bone loss caused by some ...

  6. Muscle activation patterns in the Nordic hamstring exercise: Impact of prior strain injury.

    PubMed

    Bourne, M N; Opar, D A; Williams, M D; Al Najjar, A; Shield, A J

    2016-06-01

    This study aimed to determine: (a) the spatial patterns of hamstring activation during the Nordic hamstring exercise (NHE); (b) whether previously injured hamstrings display activation deficits during the NHE; and (c) whether previously injured hamstrings exhibit altered cross-sectional area (CSA). Ten healthy, recreationally active men with a history of unilateral hamstring strain injury underwent functional magnetic resonance imaging of their thighs before and after six sets of 10 repetitions of the NHE. Transverse (T2) relaxation times of all hamstring muscles [biceps femoris long head (BFlh); biceps femoris short head (BFsh); semitendinosus (ST); semimembranosus (SM)] were measured at rest and immediately after the NHE and CSA was measured at rest. For the uninjured limb, the ST's percentage increase in T2 with exercise was 16.8%, 15.8%, and 20.2% greater than the increases exhibited by the BFlh, BFsh, and SM, respectively (P < 0.002 for all). Previously injured hamstring muscles (n = 10) displayed significantly smaller increases in T2 post-exercise than the homonymous muscles in the uninjured contralateral limb (mean difference -7.2%, P = 0.001). No muscles displayed significant between-limb differences in CSA. During the NHE, the ST is preferentially activated and previously injured hamstring muscles display chronic activation deficits compared with uninjured contralateral muscles. PMID:26059634

  7. Influence of Hip-Flexion Angle on Hamstrings Isokinetic Activity in Sprinters

    PubMed Central

    Guex, Kenny; Gojanovic, Boris; Millet, Grégoire P.

    2012-01-01

    Context Hamstrings strains are common and debilitating injuries in many sports. Most hamstrings exercises are performed at an inadequately low hip-flexion angle because this angle surpasses 70° at the end of the sprinting leg's swing phase, when most injuries occur. Objective To evaluate the influence of various hip-flexion angles on peak torques of knee flexors in isometric, concentric, and eccentric contractions and on the hamstrings-to-quadriceps ratio. Design Descriptive laboratory study. Setting Research laboratory. Patients and Other Participants Ten national-level sprinters (5 men, 5 women; age = 21.2 ± 3.6 years, height = 175 ± 6 cm, mass = 63.8 ± 9.9 kg). Intervention(s) For each hip position (0°, 30°, 60°, and 90° of flexion), participants used the right leg to perform (1) 5 seconds of maximal isometric hamstrings contraction at 45° of knee flexion, (2) 5 maximal concentric knee flexion-extensions at 60° per second, (3) 5 maximal eccentric knee flexion-extensions at 60° per second, and (4) 5 maximal eccentric knee flexion-extensions at 150° per second. Main Outcome Measure(s) Hamstrings and quadriceps peak torque, hamstrings-to-quadriceps ratio, lateral and medial hamstrings root mean square. Results We found no difference in quadriceps peak torque for any condition across all hip-flexion angles, whereas hamstrings peak torque was lower at 0° of hip flexion than at any other angle (P < .001) and greater at 90° of hip flexion than at 30° and 60° (P < .05), especially in eccentric conditions. As hip flexion increased, the hamstrings-to-quadriceps ratio increased. No difference in lateral or medial hamstrings root mean square was found for any condition across all hip-flexion angles (P > .05). Conclusions Hip-flexion angle influenced hamstrings peak torque in all muscular contraction types; as hip flexion increased, hamstrings peak torque increased. Researchers should investigate further whether an eccentric resistance training program at

  8. Distal Triceps Tendon Injuries.

    PubMed

    Keener, Jay D; Sethi, Paul M

    2015-11-01

    Acute triceps ruptures are an uncommon entity, occurring mainly in athletes, weight lifters (especially those taking anabolic steroids), and following elbow trauma. Accurate diagnosis is made clinically, although MRI may aid in confirmation and surgical planning. Acute ruptures are classified on an anatomic basis based on tear location and the degree of tendon involvement. Most complete tears are treated surgically in medically fit patients. Partial-thickness tears are managed according to the tear severity, functional demands, and response to conservative treatment. We favor an anatomic footprint repair of the triceps to provide optimal tendon to bone healing and, ultimately, functional outcome. PMID:26498552

  9. Tibialis Anterior Tendon Transfer.

    PubMed

    Mulhern, Jennifer L; Protzman, Nicole M; Brigido, Stephen A

    2016-01-01

    Tendon transfer procedures are used commonly for the correction of soft tissue imbalances and instabilities. The complete transfer and the split transfer of the tibialis anterior tendon are well-accepted methods for the treatment of idiopathic equinovarus deformity in children and adults. Throughout the literature, complete and split transfer have been shown to yield significant improvements in ankle and foot range of motion and muscle function. At present, there is insufficient evidence to recommend one procedure over the other, although the split procedure has been advocated for consistently achieving inversion to eversion muscle balance without overcorrection. PMID:26590723

  10. Posterior Tibial Tendon Transfer.

    PubMed

    Shane, Amber M; Reeves, Christopher L; Cameron, Jordan D; Vazales, Ryan

    2016-01-01

    When performed correctly with the right patient population, a tibialis posterior muscle/tendon transfer is an effective procedure. Many different methods have been established for fixating the tendon, each of which has its' own indications. Passing through the interosseous membrane is the preferred and recommended method and should be used unless this is not possible. Good surgical planning based on patient needs and expectations, along with excellent postoperative care including early range of motion and physical therapy minimizes risk of complications and allows for the optimal outcome to be achieved. PMID:26590722

  11. Comparison of the hamstring/quadriceps ratio in females during squat exercise using various foot wedges

    PubMed Central

    Yoo, Won-gyu

    2016-01-01

    [Purpose] This study compared the hamstring/quadriceps ratio in females during squat exercise using various foot wedges. [Subjects and Methods] Nine females participated in this study. Surface electrodes measurements were taken over the hamstring and quadriceps under 3 squat exercise conditions, and the hamstring/quadriceps ratio was calculated. [Results] The hamstring/quadriceps ratio was significantly increased during squat exercise in inclined wedge condition (7.4 ± 1.8), compared to the declined wedge condition (5.3 ± 2.2) and no wedge condition (6.4 ± 3.2). [Conclusion] This study suggests that squat exercise in the inclined wedge condition may be effective for increasing the hamstring/quadriceps ratio in females.

  12. Wrist circumference is related to patellar tendon thickness in healthy men and women.

    PubMed

    Nyland, John; Fried, Andrew; Maitra, Ranjan; Johnson, Darren L; Caborn, David N M

    2006-01-01

    The efficacy of dominant wrist circumference measurements to predict dominant lower extremity patellar tendon thickness at regions of interest for bone-patellar tendon-bone (BPTB) autograft harvest was studied among 24 healthy men and women. Dominant wrist circumference displayed good relationships with dominant lower extremity patellar tendon thickness as determined by two-dimensional diagnostic ultrasound. This initial screening method may assist surgeons as they consider graft selection for patients who may be at risk for developing or exacerbating preexisting patellofemoral joint or knee extensor mechanism conditions with BPTB autograft harvest. PMID:16919555

  13. Ultrasound assessment of hamstring muscle size using posterior thigh muscle thickness.

    PubMed

    Abe, Takashi; Loenneke, Jeremy P; Thiebaud, Robert S

    2016-05-01

    Several studies have investigated the relationship between ultrasound-measured muscle thickness (MT) and individual muscle cross-sectional area (CSA) and muscle volume (MV) in extremity and trunk muscles; however, the hamstring muscle has not been studied. The purpose of this study was to examine the relationship between posterior thigh MT by ultrasound and the muscle CSA and MV of the hamstring obtained by magnetic resonance imaging (MRI). Ten young women aged 20-31 had MT measured by ultrasound at three sites on the medial anterior (50% of thigh length; TL) and posterior (50% and 70% of TL) aspects of the thigh. On the same day, a series of continuous muscle CSA along the thigh was measured by MRI. In each slice, the anatomical CSA of the hamstring (biceps femoris, semitendinosus and semimembranosus) and quadriceps muscle was analysed, and the CSAs at 50% and 70% of TL and maximal CSA of the hamstring (CSAmax ) were determined. MV was calculated by multiplying CSA by slice thickness. A significant correlation was observed between posterior 50% MT and 50% hamstring CSA (r = 0·848, P = 0·002) and between posterior 70% MT and 70% hamstring CSA (r = 0·679, P = 0·031). Posterior 50% MT (r = 0·732, P = 0·016) and 50% MTxTL (r = 0·873, P = 0·001) were also correlated to hamstring MV. Anterior:posterior 50% thigh MT ratio was correlated to MV ratio of quadriceps and hamstring muscles (r = 0·803, P = 0·005). Our results suggest that posterior thigh MT reflects hamstring muscle CSA and MV. The anterior:posterior MT ratio may serve as a surrogate for MV ratio of quadriceps and hamstring. PMID:25363847

  14. Physical principles demonstrate that the biceps femoris muscle relative to the other hamstring muscles exerts the most force: implications for hamstring muscle strain injuries

    PubMed Central

    Dolman, Bronwyn; Verrall, Geoffrey; Reid, Iain

    2014-01-01

    Summary Of the hamstring muscle group the biceps femoris muscle is the most commonly injured muscle in sports requiring interval sprinting. The reason for this observation is unknown. The objective of this study was to calculate the forces of all three hamstring muscles, relative to each other, during a lengthening contraction to assess for any differences that may help explain the biceps femoris predilection for injury during interval sprinting. To calculate the displacement of each individual hamstring muscle previously performed studies on cadaveric anatomical data and hamstring kinematics during sprinting were used. From these displacement calculations for each individual hamstring muscle physical principles were then used to deduce the proportion of force exerted by each individual hamstring muscle during a lengthening muscle contraction. These deductions demonstrate that the biceps femoris muscle is required to exert proportionally more force in a lengthening muscle contraction relative to the semimembranosus and semitendinosus muscles primarily as a consequence of having to lengthen over a greater distance within the same time frame. It is hypothesized that this property maybe a factor in the known observation of the increased susceptibility of the biceps femoris muscle to injury during repeated sprints where recurrent higher force is required. PMID:25506583

  15. Anterior Cruciate Ligament Reconstruction Using a Combination of Autograft and Allograft Tendon

    PubMed Central

    Darnley, James E.; Léger-St-Jean, Benjamin; Pedroza, Angela D.; Flanigan, David C.; Kaeding, Christopher C.; Magnussen, Robert A.

    2016-01-01

    Background: Anterior cruciate ligament (ACL) reconstruction with hamstring autografts less than 8.5 mm in diameter is associated with worse patient-reported outcome scores and increased risk of revision surgery compared with reconstructions performed with larger grafts. One proposed solution to small autograft harvest is to create a hybrid graft by augmenting autografts with allograft tissue to increase graft diameter. Purpose: To compare hybrid autograft/allograft ACL reconstruction to autograft ACL reconstruction, specifically analyzing the patient-reported outcome scores and the risk of revision surgery at 2 years postoperative. Study Design: Cohort study; Level of evidence, 3. Methods: From the years 2002 to 2009, a total of 34 patients were identified from a prospectively collected database as having undergone hybrid ACL reconstruction. Twenty-seven of 34 (79.4%) patients had a 2-year follow-up. These 27 patients were matched by age (within 1 year) and sex to 27 patients who underwent hamstring autograft ACL reconstruction during the same period. At the 2-year mark, revision surgery risk and patient-reported outcome scores were compared between the 2 groups. Results: The mean age for the hybrid and matched groups (±SD) was 20.9 ± 7.0 years. Both the hybrid and control groups had 17 males and 10 females. There was no significant difference in preoperative patient-reported outcome scores, meniscus tears, or cartilage lesions between the 2 groups. Graft size was larger in the hybrid group (9.5 ± 0.6 mm) than in the autograft group (8.4 ± 0.9 mm) (P < .001). At 2 years postoperative, patient-reported outcome scores were similar between the hybrid and autograft groups. Revision surgery was required in 5 (18.5%) patients who underwent hybrid reconstruction compared with 2 (7.4%) of those who underwent autograft reconstruction (P = .26). Conclusion: Patients who undergo ACL reconstruction with hybrid hamstring grafts and hamstring autografts report similar

  16. Magnitudes of muscle activation of spine stabilizers, gluteals, and hamstrings during supine bridge to neutral position.

    PubMed

    Youdas, James W; Hartman, James P; Murphy, Brooke A; Rundle, Ashley M; Ugorowski, Jenna M; Hollman, John H

    2015-01-01

    The aim of this study was to compare the magnitude of selective core muscle activation during supine bridging to neutral exercises (three on a stable and three on an unstable surface). Surface EMG analysis was performed on the lumbar multifidus, gluteus medius, gluteus maximus, and hamstrings from 13 male and 13 female subjects. Lumbar multifidus recruitment was not influenced by exercise or condition and ranged between 29.2 and 35.9% of maximum voluntary isometric contraction (MVIC). Peak gluteus medius activation (42.0% MVIC) occurred in unstable single-leg bridge. Maximum recruitment of gluteus maximus (32.6% MVIC) appeared during stable single-leg bridge. Peak hamstring activation (59.6% MVIC) occurred during stable double-leg hamstring curl. Regardless of condition, hamstrings demonstrated high (51.9-59.6% MVIC) muscle recruitment during double-leg hamstring curls compared with the single-leg bridge or double-leg bridge. Various supine bridging to neutral exercises activated the hamstrings at levels conducive to strengthening, whereas recruitment of lumbar multifidus, gluteus medius, and gluteus maximus promoted endurance training. Clinically, we were unable to conclude the unstable support surface was preferable to the stable surface for boosting muscle recruitment of spine stabilizers, gluteals, and hamstring muscles during supine bridge to neutral position. PMID:25671354

  17. Investigation of 2D and 3D electrospun scaffolds intended for tendon repair.

    PubMed

    Bosworth, L A; Alam, N; Wong, J K; Downes, S

    2013-06-01

    Two-dimensional (2D) electrospun fibre mats have been investigated as fibrous sheets intended as biomaterials scaffolds for tissue repair. It is recognised that tissues are three-dimensional (3D) structures and that optimisation of the fabrication process should include both 2D and 3D scaffolds. Understanding the relative merits of the architecture of 2D and 3D scaffolds for tendon repair is required. This study investigated three different electrospun scaffolds based on poly(ε-caprolactone) fibres intended for repair of injured tendons, referred to as; 2D random sheet, 2D aligned sheet and 3D bundles. 2D aligned fibres and 3D bundles mimicked the parallel arrangement of collagen fibres in natural tendon and 3D bundles further replicated the tertiary layer of a tendon's hierarchical configuration. 3D bundles demonstrated greatest tensile properties, being significantly stronger and stiffer than 2D aligned and 2D random fibres. All scaffolds supported adhesion and proliferation of tendon fibroblasts. Furthermore, 2D aligned sheets and 3D bundles allowed guidance of the cells into a parallel, longitudinal arrangement, which is similar to tendon cells in the native tissue. With their superior physical properties and ability to better replicate tendon tissue, the 3D electrospun scaffolds warrant greater investigation as synthetic grafts in tendon repair. PMID:23504088

  18. Freeze-Dried Tendon Allografts as Tissue Engineering Scaffolds for Gdf5 Gene Delivery

    PubMed Central

    Basile, Patrick; Dadali, Tulin; Jacobson, Justin; Hasslund, Sys; Ulrich-Vinther, Michael; Søballe, Kjeld; Nishio, Yasuhiko; Drissi, M Hicham; Langstein, Howard N; Mitten, David J; O’Keefe, Regis J; Schwarz, Edward M; Awad, Hani A

    2009-01-01

    Tendon reconstruction using grafts often results in adhesions that limit joint flexion. These adhesions are precipitated by inflammation, fibrosis, and paucity of tendon differentiation signals during healing. To study this problem, we developed a mouse model in which the FDL tendon is reconstructed using a live autograft or a freeze-dried allograft and identified Gdf5 as a therapeutic target. Here we investigate the potential of rAAV-Gdf5 coated freeze-dried tendon allografts as “therapeutically-endowed” tissue engineering scaffolds to reduce adhesions. In reporter gene studies we demonstrate that rAAV-coated tendon allografts mediate efficient transduction of adjacent soft tissues, with expression peaking at 7-days. We also demonstrate that rAAV-Gdf5 vector significantly accelerates wound healing in an in vitro fibroblast scratch model, and when loaded onto freeze-dried FDL tendon allografts significantly improves the metatarsophalangeal joint flexion compared to rAAV-lacZ controls. Collectively, our data demonstrate the feasibility and efficacy of therapeutic tendon allograft processing as a novel paradigm in tissue engineering to address difficult clinical problems such as tendon adhesions. PMID:18180771

  19. Hamstring Musculotendon Dynamics during Stance and Swing Phases of High Speed Running

    PubMed Central

    Chumanov, Elizabeth S.; Heiderscheit, Bryan C.; Thelen, Darryl G.

    2011-01-01

    Introduction Hamstring strain injuries are common in sports that involve high speed running. It remains uncertain whether the hamstrings are susceptible to injury during late swing phase, when the hamstrings are active and lengthening, or during stance, when contact loads are present. In this study we used forward dynamic simulations to compare hamstring musculotendon stretch, loading and work done during stance and swing phases of high speed running gait cycles. Methods Whole body kinematics, EMG activities and ground reactions were collected as 12 subjects ran on an instrumented treadmill at speeds ranging from 80% to maximum (average of 7.8 m/s). Subject-specific simulations were then created using a whole body musculoskeletal model that included fifty-two Hill-type musculotendon units acting about the hip and knee. A computed muscle control algorithm was used to determine muscle excitation patterns that drove the limb to track measured hip and knee sagittal plane kinematics, with measured ground reactions applied to the limb. Results The hamstrings lengthened under load from 50% to 90% of the gait cycle (swing), and then shortened under load from late swing through stance. While peak hamstring stretch was invariant with speed, lateral hamstring (biceps femoris) loading increased significantly with speed, and was greatest during swing at the fastest speed. The biarticular hamstrings performed negative work on the system only during swing phase, with the amount of negative work increasing significantly with speed. Conclusion We concluded that the large inertial loads during high speed running appear to make the hamstrings most susceptible to injury during swing phase when compared to stance phase. This information is relevant for scientifically establishing effective muscle injury prevention and rehabilitation programs. PMID:20689454

  20. Peroneal Tendon Reconstruction and Coverage for Treatment of Septic Peroneal Tenosynovitis: A Devastating Complication of Lateral Ankle Ligament Reconstruction With a Tendon Allograft.

    PubMed

    Schade, Valerie L; Harsha, Wayne; Rodman, Caitlin; Roukis, Thomas S

    2016-01-01

    Septic peroneal tenosynovitis is a rare and significant challenge. A search of peer-reviewed published studies revealed only 5 case reports to guide treatment, none of which resulted in significant loss of both peroneal tendons necessitating reconstruction. No clear guidance is available regarding how to provide reliable reconstruction of both peroneal tendons after a significant loss secondary to septic tenosynovitis. In the present report, we describe the case of a young, active-duty soldier who underwent lateral ankle ligament reconstruction with a tendon allograft whose postoperative course was complicated by septic peroneal tenosynovitis resulting in significant loss of both peroneal tendons. Reconstruction was achieved in a staged fashion with the use of silicone rods and external fixation to maintain physiologic tension and preserve peroneal tendon function, followed by reconstruction of both peroneal tendons and the superior peroneal retinaculum with a tensor fascia lata autograft. Soft tissue coverage was obtained with an anterolateral thigh free tissue transfer and a split-thickness skin graft. The patient returned to full activity as an active-duty soldier with minimal pain and no instability of the right lower extremity. The muscle strength of both peroneal tendons remained at 5 of 5, and no objective findings of ankle instability were seen at 3.5 years postoperatively. PMID:26002675

  1. [Diseases of the Achilles tendon].

    PubMed

    Schönbauer, H R

    1986-01-01

    In this report diseases of the Achilles tendon are discussed. First an anatomical survey of this region is presented including anatomical variations together with the results of the author's own investigations on corpses. Certain positions and insertions of the plantaris tendon with respect to the Achilles tendon may have pathological influence. Pathological aspects are discussed after a review of the physiology of the Achilles tendon, including functional and tensile tests. The clinical picture changes according to the location of the pathological disorder--tendon, paratenon, insertion and bursae--and whether the disease is acute or chronic. There are various reasons for degenerative changes in the tendon, which can even lead to rupture. Surgical and non-surgical treatment and their indications are presented. In conclusion treatment methods and their results for 36 cases are given. PMID:3087066

  2. Scaffolds in Tendon Tissue Engineering

    PubMed Central

    Longo, Umile Giuseppe; Lamberti, Alfredo; Petrillo, Stefano; Maffulli, Nicola; Denaro, Vincenzo

    2012-01-01

    Tissue engineering techniques using novel scaffold materials offer potential alternatives for managing tendon disorders. Tissue engineering strategies to improve tendon repair healing include the use of scaffolds, growth factors, cell seeding, or a combination of these approaches. Scaffolds have been the most common strategy investigated to date. Available scaffolds for tendon repair include both biological scaffolds, obtained from mammalian tissues, and synthetic scaffolds, manufactured from chemical compounds. Preliminary studies support the idea that scaffolds can provide an alternative for tendon augmentation with an enormous therapeutic potential. However, available data are lacking to allow definitive conclusion on the use of scaffolds for tendon augmentation. We review the current basic science and clinical understanding in the field of scaffolds and tissue engineering for tendon repair. PMID:22190961

  3. Traumatic flexor tendon injuries.

    PubMed

    Lapegue, F; Andre, A; Brun, C; Bakouche, S; Chiavassa, H; Sans, N; Faruch, M

    2015-12-01

    The flexor system of the fingers consisting of flexor tendons and finger pulleys is a key anatomic structure for the grasping function. Athletes and manual workers are particularly at risk for closed injuries of the flexor system: ruptured pulleys, ruptures of the flexor digitorum profundus from its distal attachment ("jersey finger"), and less frequently, ruptures of the flexor digitorum superficialis and of the lumbrical muscles. Open injuries vary more and their imaging features are more complex since tendons may be torn in several locations, the locations may be unusual, the injuries may be associated with nerve and vascular injuries, fibrosis… Sonography is the best imaging modality to associate with the clinical exam for it allows an experienced physician to make an accurate and early diagnosis, crucial to appropriate early treatment planning. PMID:26564614

  4. Magnesium inference screw supports early graft incorporation with inhibition of graft degradation in anterior cruciate ligament reconstruction

    NASA Astrophysics Data System (ADS)

    Cheng, Pengfei; Han, Pei; Zhao, Changli; Zhang, Shaoxiang; Zhang, Xiaonong; Chai, Yimin

    2016-05-01

    Patients after anterior cruciate ligament (ACL) reconstruction surgery commonly encounters graft failure in the initial phase of rehabilitation. The inhibition of graft degradation is crucial for the successful reconstruction of the ACL. Here, we used biodegradable high-purity magnesium (HP Mg) screws in the rabbit model of ACL reconstruction with titanium (Ti) screws as a control and analyzed the graft degradation and screw corrosion using direct pull-out tests, microCT scanning, and histological and immunohistochemical staining. The most noteworthy finding was that tendon graft fixed by HP Mg screws exhibited biomechanical properties substantially superior to that by Ti screws and the relative area of collagen fiber at the tendon-bone interface was much larger in the Mg group, when severe graft degradation was identified in the histological analysis at 3 weeks. Semi-quantitative immunohistochemical results further elucidated that the MMP-13 expression significantly decreased surrounding HP Mg screws with relatively higher Collagen II expression. And HP Mg screws exhibited uniform corrosion behavior without displacement or loosening in the femoral tunnel. Therefore, our results demonstrated that Mg screw inhibited graft degradation and improved biomechanical properties of tendon graft during the early phase of graft healing and highlighted its potential in ACL reconstruction.

  5. Magnesium inference screw supports early graft incorporation with inhibition of graft degradation in anterior cruciate ligament reconstruction.

    PubMed

    Cheng, Pengfei; Han, Pei; Zhao, Changli; Zhang, Shaoxiang; Zhang, Xiaonong; Chai, Yimin

    2016-01-01

    Patients after anterior cruciate ligament (ACL) reconstruction surgery commonly encounters graft failure in the initial phase of rehabilitation. The inhibition of graft degradation is crucial for the successful reconstruction of the ACL. Here, we used biodegradable high-purity magnesium (HP Mg) screws in the rabbit model of ACL reconstruction with titanium (Ti) screws as a control and analyzed the graft degradation and screw corrosion using direct pull-out tests, microCT scanning, and histological and immunohistochemical staining. The most noteworthy finding was that tendon graft fixed by HP Mg screws exhibited biomechanical properties substantially superior to that by Ti screws and the relative area of collagen fiber at the tendon-bone interface was much larger in the Mg group, when severe graft degradation was identified in the histological analysis at 3 weeks. Semi-quantitative immunohistochemical results further elucidated that the MMP-13 expression significantly decreased surrounding HP Mg screws with relatively higher Collagen II expression. And HP Mg screws exhibited uniform corrosion behavior without displacement or loosening in the femoral tunnel. Therefore, our results demonstrated that Mg screw inhibited graft degradation and improved biomechanical properties of tendon graft during the early phase of graft healing and highlighted its potential in ACL reconstruction. PMID:27210585

  6. Magnesium inference screw supports early graft incorporation with inhibition of graft degradation in anterior cruciate ligament reconstruction

    PubMed Central

    Cheng, Pengfei; Han, Pei; Zhao, Changli; Zhang, Shaoxiang; Zhang, Xiaonong; Chai, Yimin

    2016-01-01

    Patients after anterior cruciate ligament (ACL) reconstruction surgery commonly encounters graft failure in the initial phase of rehabilitation. The inhibition of graft degradation is crucial for the successful reconstruction of the ACL. Here, we used biodegradable high-purity magnesium (HP Mg) screws in the rabbit model of ACL reconstruction with titanium (Ti) screws as a control and analyzed the graft degradation and screw corrosion using direct pull-out tests, microCT scanning, and histological and immunohistochemical staining. The most noteworthy finding was that tendon graft fixed by HP Mg screws exhibited biomechanical properties substantially superior to that by Ti screws and the relative area of collagen fiber at the tendon-bone interface was much larger in the Mg group, when severe graft degradation was identified in the histological analysis at 3 weeks. Semi-quantitative immunohistochemical results further elucidated that the MMP-13 expression significantly decreased surrounding HP Mg screws with relatively higher Collagen II expression. And HP Mg screws exhibited uniform corrosion behavior without displacement or loosening in the femoral tunnel. Therefore, our results demonstrated that Mg screw inhibited graft degradation and improved biomechanical properties of tendon graft during the early phase of graft healing and highlighted its potential in ACL reconstruction. PMID:27210585

  7. Tribological characteristics of healthy tendon.

    PubMed

    Theobald, Peter S; Dowson, Duncan; Khan, Ilyas M; Jones, Michael D

    2012-07-26

    Tendons transfer muscular forces efficiently and painlessly, facilitating joint motion. Whilst the tribology of articular cartilage is constantly explored, a poorer understanding remains of tendon lubrication and friction. This study reports experimental data describing the tribological characteristics of tendon and its surrounding tissue, before presenting an arithmetic solution to facilitate numerical modelling. The experimental characteristics of the tensile (i.e. mid-substance) and compressive (i.e. fibrocartilaginous) regions of bovine flexor tendon were investigated using a pin-on-plate tribometer, with immunofluroscence analysis describing the relative intensity and distribution of surface-bound lubricin. Arithmetic analysis considering the digital extensor tendon determined that, in physiological conditions, the tensile tendon region was able to generate elastohydrodynamic lubrication (EHL). The equivalent region of compressive tendon exhibited a higher intensity of surface-bound lubricin which, it is hypothesised, serves to minimise the increased frictional resistance due to generating only mixed or boundary lubrication regimes. Arithmetic analysis indicates that, given a more favourable biomechanical environment, this region can also generate EHL. Whilst acknowledging the limitations of transferring data from an animal model to a clinical environment, by providing the first data and equations detailing the film thicknesses and lubrication regime for these two tendon regions it is hoped that clinicians, engineers and scientists can consider improved clinical strategies to tackle both tendinopathy and tendon rupture. PMID:22704825

  8. Persistent tight hamstrings following conservative treatment for apophyseal ring fracture in adolescent athletes: critical appraisal.

    PubMed

    Miyagi, Ryo; Sairyo, Koichi; Sakai, Toshinori; Tezuka, Fumitake; Kitagawa, Yasuhiro; Dezawa, Akira

    2014-01-01

    Apophyseal ring fracture is a unique disease in children and adolescents. Its clinical features include low back pain, sciatica, paravertebral muscle spasm and tenderness, restricted back motion, neurological symptoms, and tight hamstrings. For all athletes, body flexibility is one of the most important factors for better performance. Therefore, persistent tight hamstrings has a negative influence on athletic performance. In this report, we present two adolescent athletes with apophyseal ring fracture treated successfully by conservative treatment for severe low back pain (LBP) and leg pain, despite having persistent tight hamstrings for more than one year. Unlike herniated nucleus pulposus, bony fragments in the spinal canal never disappear. Although conservative treatment can alleviate LBP and leg pain, surgical removal of fragments is considered when symptoms such as tight hamstrings and restricted lumbar motion due to canal stenosis are found, particularly in athletes. PMID:25264071

  9. Preventive Effects of Eccentric Training on Acute Hamstring Muscle Injury in Professional Baseball

    PubMed Central

    Seagrave, Richard A.; Perez, Luis; McQueeney, Sean; Toby, E. Bruce; Key, Vincent; Nelson, Joshua D.

    2014-01-01

    Background: Hamstring injuries are the second most common injury causing missed days in professional baseball field players. Recent studies have shown the preventive benefit of eccentric conditioning on the hamstring muscle group in injury prevention. Specifically, Nordic-type exercises have been shown to decrease the incidence of acute hamstring injuries in professional athletes. Purpose: This was a prospective study performed in coordination with a single Major League Baseball (MLB) organization (major and minor league teams) that targeted the effects of Nordic exercises on the incidence of acute hamstring injuries in the professional-level baseball player. Study Design: Prospective cohort study; Level of evidence, 2. Methods: The daily workouts of 283 professional baseball players throughout all levels of a single MLB organization were prospectively recorded. The intervention group participated in the Nordic exercise program and was compared with a randomly selected control group of professional athletes within the organization not participating in the exercise program. The incidence of hamstring injuries in both groups was compared, and the total number of days missed due to injury was compared with the 2 previous seasons. Results: There were 10 hamstring injuries that occurred during the 2012 season among the 283 professional athletes that required removal from play. There were no injuries that occurred in the intervention group (n = 65, 0.00%; P = .0381). The number needed to treat (NNT) to prevent 1 hamstring injury was 11.3. The average repetitions per week of the injured group were assessed at multiple time points (2, 4, 6, and total weeks) prior to injury. There were significantly fewer repetitions per week performed in the injured group at all time points compared with overall average repetitions per week in the noninjured group (P = .0459, .0127, .0164, and .0299, respectively). After beginning the Nordic exercise program, there were 136 total days

  10. Mechanisms of collagen fibril alignment in tendon injury: from tendon regeneration to artificial tendon.

    PubMed

    Torigoe, Kojun; Tanaka, Hirohito F; Yonenaga, Kazumichi; Ohkochi, Hiroki; Miyasaka, Muneo; Sato, Ryota; Kuzumaki, Toru; Yoshida, Kazuharu; Yoshida, Toshiko

    2011-12-01

    The process by which collagen fibrils are aligned following tendon injury remains unknown. Therefore, we analyzed the process of tendon regeneration by transmission electron microscopy, using a film model method. In mice, the Achilles tendon of medial head was transected. On day 3, after only the proximal end of the transected tendon was placed on film and kept in vivo, a translucent substance containing granules, called tendon gel, was secreted. On day 5, the granules assembled in a loose (L) layer, and coalesced tightly in a dense (D) layer, forming an L-D-L layered pattern. On day 10, granules showed high electron density in H layers, which developed into D-H-D layers on day 13. The distal end was placed on film to face the proximal end. On day 10, the tendon gel showed a D-H-D layer pattern. On day 11, mechanical stress from muscular constriction changed the tendon gel to aligned collagen fibrils (6 ± 2 nm in diameter). Thereafter, the diameter of the fibrils increased. Tendon gel harvested on day 5 or day 10 was pulled manually or by hanging weights (about 0.6 MPa). Aligned collagen fibrils (32 ± 7 nm in diameter) were created by traction using tendon gel harvested on day 10. PMID:21618275

  11. Effects of Sacrificing Tensor Tympani Muscle Tendon When Manubrium of Malleus Is Foreshortened in Type I Tympanoplasty

    PubMed Central

    Vadiya, Sohil

    2015-01-01

    The current study aims at observing effects of sacrificing the tensor tympani tendon when manubrium of malleus is foreshortened or retracted on graft uptake, hearing improvement, and occurrence of complications if any during type I tympanoplasty surgery for central perforations. 42 patients were included in group A where the tensor tendon was sectioned and 42 patients were included in group B where the tensor tympani tendon was retained and kept intact. Graft uptake rates are very good in both groups but hearing improvement was found significantly better in group A than group B. No unusual or undesired complications were seen in any of the cases. Sectioning of tensor tympani tendon is safe and effective procedure in cases where manubrium is foreshortened. PMID:26697069

  12. Contribution of Hamstring Fatigue to Quadriceps Inhibition Following Lumbar Extension Exercise

    PubMed Central

    Hart, Joseph M.; Kerrigan, D. Casey; Fritz, Julie M.; Saliba, Ethan N.; Gansneder, Bruce; Ingersoll, Christopher D.

    2006-01-01

    The purpose of this study was to determine the contribution of hamstrings and quadriceps fatigue to quadriceps inhibition following lumbar extension exercise. Regression models were calculated consisting of the outcome variable: quadriceps inhibition and predictor variables: change in EMG median frequency in the quadriceps and hamstrings during lumbar fatiguing exercise. Twenty-five subjects with a history of low back pain were matched by gender, height and mass to 25 healthy controls. Subjects performed two sets of fatiguing isometric lumbar extension exercise until mild (set 1) and moderate (set 2) fatigue of the lumbar paraspinals. Quadriceps and hamstring EMG median frequency were measured while subjects performed fatiguing exercise. A burst of electrical stimuli was superimposed while subjects performed an isometric maximal quadriceps contraction to estimate quadriceps inhibition after each exercise set. Results indicate the change in hamstring median frequency explained variance in quadriceps inhibition following the exercise sets in the history of low back pain group only. Change in quadriceps median frequency explained variance in quadriceps inhibition following the first exercise set in the control group only. In conclusion, persons with a history of low back pain whose quadriceps become inhibited following lumbar paraspinal exercise may be adapting to the fatigue by using their hamstring muscles more than controls. Key Points A neuromuscular relationship between the lumbar paraspinals and quadriceps while performing lumbar extension exercise may be influenced by hamstring muscle fatigue. QI following lumbar extension exercise in persons with a history of LBP group may involve significant contribution from the hamstring muscle group. More hamstring muscle contribution may be a necessary adaptation in the history of LBP group due to weaker and more fatigable lumbar extensors. PMID:24198683

  13. The biomechanics of running in athletes with previous hamstring injury: A case-control study.

    PubMed

    Daly, C; McCarthy Persson, U; Twycross-Lewis, R; Woledge, R C; Morrissey, D

    2016-04-01

    Hamstring injury is prevalent with persistently high reinjury rates. We aim to inform hamstring rehabilitation by exploring the electromyographic and kinematic characteristics of running in athletes with previous hamstring injury. Nine elite male Gaelic games athletes who had returned to sport after hamstring injury and eight closely matched controls sprinted while lower limb kinematics and muscle activity of the previously injured biceps femoris, bilateral gluteus maximus, lumbar erector spinae, rectus femoris, and external oblique were recorded. Intergroup comparisons of muscle activation ratios and kinematics were performed. Previously injured athletes demonstrated significantly reduced biceps femoris muscle activation ratios with respect to ipsilateral gluteus maximus (maximum difference -12.5%, P = 0.03), ipsilateral erector spinae (maximum difference -12.5%, P = 0.01), ipsilateral external oblique (maximum difference -23%, P = 0.01), and contralateral rectus femoris (maximum difference -22%, P = 0.02) in the late swing phase. We also detected sagittal asymmetry in hip flexion (maximum 8°, P = 0.01), pelvic tilt (maximum 4°, P = 0.02), and medial rotation of the knee (maximum 6°, P = 0.03) effectively putting the hamstrings in a lengthened position just before heel strike. Previous hamstring injury is associated with altered biceps femoris associated muscle activity and potentially injurious kinematics. These deficits should be considered and addressed during rehabilitation. PMID:25913546

  14. Hamstrings and iliotibial band forces affect knee kinematics and contact pattern.

    PubMed

    Kwak, S D; Ahmad, C S; Gardner, T R; Grelsamer, R P; Henry, J H; Blankevoort, L; Ateshian, G A; Mow, V C

    2000-01-01

    Many clinical studies have emphasized the role of the hamstrings and the iliotibial band on knee mechanics, although few biomechanical studies have investigated it. This study therefore examined two hypotheses: (a) with loading of the hamstrings, the tibia translates posteriorly and rotates externally and the tibial contact pattern shifts anteriorly; furthermore, the changes in tibial kinematics alter patellar kinematics and contact; and (b) loading the iliotibial band alters the kinematics and contact pattern of the tibiofemoral joint similarly to loading the hamstrings, and loading the iliotibial band laterally translates the patella and its contact location. Five cadaveric knee specimens were tested with a specially designed knee-joint testing machine in an open-chain configuration. At various flexion angles, the knees were tested always with a quadriceps force but with and without a hamstrings force and with and without an iliotibial band force. The results support the first hypothesis. Hence, the hamstrings may be important anterior and rotational stabilizers of the tibia, a role similar to that of the anterior cruciate ligament. The results also support the second hypothesis, although the iliotibial band force had a smaller effect on the tibia than did the hamstrings force. Both forces also changed patellar kinematics and contact, demonstrating that these structures should also be considered during the clinical management of patellar disorders. PMID:10716285

  15. Distal tears of the hamstring muscles: review of the literature and our results of surgical treatment

    PubMed Central

    Lempainen, Lasse; Sarimo, Janne; Mattila, Kimmo; Heikkilä, Jouni; Orava, Sakari

    2007-01-01

    Background Hamstring strains are among the most frequent injuries in sports, especially in events requiring sprinting and running. Distal tears of the hamstring muscles requiring surgical treatment are scarcely reported in the literature. Objective To evaluate the results of surgical treatment for distal hamstring tears. Design A case series of 18 operatively treated distal hamstring muscle tears combined with a review of previously published cases in the English literature. Retrospective study; level of evidence 4. Setting Mehiläinen Sports Trauma Research Center, Mehiläinen Hospital and Sports Clinic, Turku, Finland. Patients Between 1992 and 2005, a total of 18 athletes with a distal hamstring tear were operated at our centre. Main outcome measurements At follow‐up, the patients were asked about possible symptoms (pain, weakness, stiffness) and their return to the pre‐injury level of sport. Results The final results were rated excellent in 13 cases, good in 1 case, fair in 3 cases and poor in 1 case. 14 of the 18 patients were able to return to their former level of sport after an average of 4 months (range 2–6 months). Conclusions Surgical treatment seems to be beneficial in distal hamstring tears in selected cases. PMID:17138628

  16. Principles of tendon transfers.

    PubMed

    Coulet, B

    2016-04-01

    Tendon transfers are carried out to restore functional deficits by rerouting the remaining intact muscles. Transfers are highly attractive in the context of hand surgery because of the possibility of restoring the patient's ability to grip. In palsy cases, tendon transfers are only used when a neurological procedure is contraindicated or has failed. The strategy used to restore function follows a common set of principles, no matter the nature of the deficit. The first step is to clearly distinguish between deficient muscles and muscles that could be transferred. Next, the type of palsy will dictate the scope of the program and the complexity of the gripping movements that can be restored. Based on this reasoning, a surgical strategy that matches the means (transferable muscles) with the objectives (functions to restore) will be established and clearly explained to the patient. Every paralyzed hand can be described using three parameters. 1) Deficient segments: wrist, thumb and long fingers; 2) mechanical performance of muscles groups being revived: high energy-wrist extension and finger flexion that require strong transfers with long excursion; low energy-wrist flexion and finger extension movements that are less demanding mechanically, because they can be accomplished through gravity alone in some cases; 3) condition of the two primary motors in the hand: extrinsics (flexors and extensors) and intrinsics (facilitator). No matter the type of palsy, the transfer surgery follows the same technical principles: exposure, release, fixation, tensioning and rehabilitation. By performing an in-depth analysis of each case and by following strict technical principles, tendon transfer surgery leads to reproducible results; this allows the surgeon to establish clear objectives for the patient preoperatively. PMID:27117119

  17. TLP tendon bottom connector

    SciTech Connect

    Owens, H.S.

    1986-09-16

    This patent describes a bottom connector for connecting a tendon segment of a tension leg platform to a subsea template which includes a receptacle for the connector comprising: a first body member adapted to be received within an anchor receptacle, a second body member connected to the first body member through a flexible joint for universally pivotal movement and adapted to be connected to the tendon segment, a latch carrier movable with respect to the first body member and having latch segments pivotally connected to the latch carrier, the latch segments being such that in one position of the latch carrier, the latch segments engage both a recess in the receptacle and the first body member when the connector is inserted into the receptacle a sufficient distance so that the latch segments and carrier will react to the recess and such that when the latch carrier is in another position, the latch segments are clear of the recess to enable the connector to move further into the receptacle or to allow the bottom connector to be removed from the receptacle, and release means operative to maintain the carrier in the other position if a decision is made to remove the connector from the receptacle.

  18. Elevated gastrocnemius forces compensate for decreased hamstrings forces during the weight-acceptance phase of single-leg jump landing: implications for anterior cruciate ligament injury risk.

    PubMed

    Morgan, Kristin D; Donnelly, Cyril J; Reinbolt, Jeffrey A

    2014-10-17

    Approximately 320,000 anterior cruciate ligament (ACL) injuries in the United States each year are non-contact injuries, with many occurring during a single-leg jump landing. To reduce ACL injury risk, one option is to improve muscle strength and/or the activation of muscles crossing the knee under elevated external loading. This study's purpose was to characterize the relative force production of the muscles supporting the knee during the weight-acceptance (WA) phase of single-leg jump landing and investigate the gastrocnemii forces compared to the hamstrings forces. Amateur male Western Australian Rules Football players completed a single-leg jump landing protocol and six participants were randomly chosen for further modeling and simulation. A three-dimensional, 14-segment, 37 degree-of-freedom, 92 muscle-tendon actuated model was created for each participant in OpenSim. Computed muscle control was used to generate 12 muscle-driven simulations, 2 trials per participant, of the WA phase of single-leg jump landing. A one-way ANOVA and Tukey post-hoc analysis showed both the quadriceps and gastrocnemii muscle force estimates were significantly greater than the hamstrings (p<0.001). Elevated gastrocnemii forces corresponded with increased joint compression and lower ACL forces. The elevated quadriceps and gastrocnemii forces during landing may represent a generalized muscle strategy to increase knee joint stiffness, protecting the knee and ACL from external knee loading and injury risk. These results contribute to our understanding of how muscle's function during single-leg jump landing and should serve as the foundation for novel muscle-targeted training intervention programs aimed to reduce ACL injuries in sport. PMID:25218505

  19. Lower hamstring extensibility in men compared to women is explained by differences in stretch tolerance

    PubMed Central

    2014-01-01

    Background This study examined whether passive hamstring tissue stiffness and/or stretch tolerance explain the relationship between sex and hamstring extensibility. Methods Ninety healthy participants, 45 men and 45 women (mean ± SD; age 24.6 ± 5.9 years, height 1.72 ± 0.09 m, weight 74.6 ± 14.1 kg) volunteered for this study. The instrumented straight leg raise was used to determine hamstring extensibility and allow measurement of stiffness and stretch tolerance (visual analog pain score, VAS). Results Hamstring extensibility was 9.9° greater in women compared to men (p = 0.003). VAS scores were 16 mm lower in women (p = 0.001). Maximal stiffness (maximal applied torque) was not different between men and women (p = 0.42). Passive stiffness (slope from 20-50° hip flexion) was 0.09 Nm.°-1 lower in women (p = 0.025). For women, linear and stepwise regression showed that no predictor variables were associated with hamstring extensibility (adjusted r2 = -0.03, p = 0.61). For men, 44% of the variance in hamstring extensibility was explained by VAS and maximal applied torque (adjusted r2 = 0.44, p < 0.001), with 41% of the model accounted for by the relationship between higher VAS scores and lower extensibility (standardized β coefficient = -0.64, p < 0.001). Conclusions The results of this study suggest that stretch tolerance and not passive stiffness explains hamstring extensibility, but this relationship is only manifest in men. PMID:25000977

  20. Effects of hamstring-emphasized neuromuscular training on strength and sprinting mechanics in football players.

    PubMed

    Mendiguchia, J; Martinez-Ruiz, E; Morin, J B; Samozino, P; Edouard, P; Alcaraz, P E; Esparza-Ros, F; Mendez-Villanueva, A

    2015-12-01

    The objective of this study was to examine the effects of a neuromuscular training program combining eccentric hamstring muscle strength, plyometrics, and free/resisted sprinting exercises on knee extensor/flexor muscle strength, sprinting performance, and horizontal mechanical properties of sprint running in football (soccer) players. Sixty footballers were randomly assigned to an experimental group (EG) or a control group (CG). Twenty-seven players completed the EG and 24 players the CG. Both groups performed regular football training while the EG performed also a neuromuscular training during a 7-week period. The EG showed a small increases in concentric quadriceps strength (ES = 0.38/0.58), a moderate to large increase in concentric (ES = 0.70/0.74) and eccentric (ES = 0.66/0.87) hamstring strength, and a small improvement in 5-m sprint performance (ES = 0.32). By contrast, the CG presented lower magnitude changes in quadriceps (ES = 0.04/0.29) and hamstring (ES = 0.27/0.34) concentric muscle strength and no changes in hamstring eccentric muscle strength (ES = -0.02/0.11). Thus, in contrast to the CG (ES = -0.27/0.14), the EG showed an almost certain increase in the hamstring/quadriceps strength functional ratio (ES = 0.32/0.75). Moreover, the CG showed small magnitude impairments in sprinting performance (ES = -0.35/-0.11). Horizontal mechanical properties of sprint running remained typically unchanged in both groups. These results indicate that a neuromuscular training program can induce positive hamstring strength and maintain sprinting performance, which might help in preventing hamstring strains in football players. PMID:25556888

  1. Influence on Strength and Flexibility of a Swing Phase-Specific Hamstring Eccentric Program in Sprinters' General Preparation.

    PubMed

    Guex, Kenny J; Lugrin, Véronique; Borloz, Stéphane; Millet, Grégoire P

    2016-02-01

    Hamstring injuries are common in sprinters and mainly occur during the terminal swing phase. Eccentric training has been shown to reduce hamstring injury rate by improving several risk factors. The aim of this study was to test the hypothesis that an additional swing phase-specific hamstring eccentric training in well-trained sprinters performed at the commencement of the winter preparation is more efficient to improve strength, ratio, optimum angle, and flexibility than a similar program without hamstring eccentric exercises. Twenty sprinters were randomly allocated to an eccentric (n = 10) or a control group (n = 10). Both groups performed their usual track and field training throughout the study period. Sprinters in the eccentric group performed an additional 6-week hamstring eccentric program, which was specific to the swing phase of the running cycle (eccentric high-load open-chain kinetic movements covering the whole hamstring length-tension relationship preformed at slow to moderate velocity). Isokinetic and flexibility measurements were performed before and after the intervention. The eccentric group increased hamstring peak torques in concentric at 60° · s(-1) by 16% (p < 0.001) and at 240° · s(-1) by 10% (p < 0.01), in eccentric at 30° · s(-1) by 20% (p < 0.001) and at 120° · s(-1) by 22% (p < 0.001), conventional and functional ratios by 12% (p < 0.001), and flexibility by 4° (p < 0.01), whereas the control group increased hamstring peak torques only in eccentric at 30° · s(-1) by 6% (p ≤ 0.05) and at 120° · s(-1) by 6% (p < 0.01). It was concluded that an additional swing phase-specific hamstring eccentric training in sprinters seems to be crucial to address different risk factors for hamstring strain injuries, such as eccentric and concentric strength, hamstring-to-quadriceps ratio ratio, and flexibility. PMID:26200198

  2. Partial Tendon Release for Treatment of a Symptomatic Snapping Biceps Femoris Tendon

    PubMed Central

    Crow, Scott A.; Quach, Tony; McAllister, David R.

    2009-01-01

    Snapping of the biceps femoris tendon over the fibular head is an uncommon condition. Reported causes include an anomalous insertion of the tendon, trauma at the insertion site of the tendon, and an abnormality of the fibular head. This article reports a case of a painful snapping biceps femoris tendon in a patient without an anomalous tendon insertion or an abnormality of the fibular head. Partial release of the superior aspect of the tendon resulted in resolution of symptoms. PMID:23015904

  3. Implantation of a Novel Biologic and Hybridized Tissue Engineered Bioimplant in Large Tendon Defect: An In Vivo Investigation

    PubMed Central

    Oryan, Ahmad; Moshiri, Ali; Parizi, Abdolhamid Meimandi

    2014-01-01

    Surgical reconstruction of large Achilles tendon defects is technically demanding. There is no standard method, and tissue engineering may be a valuable option. We investigated the effects of 3D collagen and collagen-polydioxanone sheath (PDS) implants on a large tendon defect model in rabbits. Ninety rabbits were divided into three groups: control, collagen, and collagen-PDS. In all groups, 2 cm of the left Achilles tendon were excised and discarded. A modified Kessler suture was applied to all injured tendons to retain the gap length. The control group received no graft, the treated groups were repaired using the collagen only or the collagen-PDS prostheses. The bioelectrical characteristics of the injured areas were measured at weekly intervals. The animals were euthanized at 60 days after the procedure. Gross, histopathological and ultrastructural morphology and biophysical characteristics of the injured and intact tendons were investigated. Another 90 pilot animals were also used to investigate the inflammatory response and mechanism of graft incorporation during tendon healing. The control tendons showed severe hyperemia and peritendinous adhesion, and the gastrocnemius muscle of the control animals showed severe atrophy and fibrosis, with a loose areolar connective tissue filling the injured area. The tendons receiving either collagen or collagen-PDS implants showed lower amounts of peritendinous adhesion, hyperemia and muscle atrophy, and a dense tendon filled the defect area. Compared to the control tendons, application of collagen and collagen-PDS implants significantly improved water uptake, water delivery, direct transitional electrical current and tissue resistance to direct transitional electrical current. Compared to the control tendons, both prostheses showed significantly increased diameter, density and alignment of the collagen fibrils and maturity of the tenoblasts at ultrastructure level. Both prostheses influenced favorably tendon healing

  4. Isokinetic Hamstrings:Quadriceps Ratios in Intercollegiate Athletes

    PubMed Central

    Fogarty, Tracey D.; Mahaffey, Brian L.

    2001-01-01

    Objective: To compare the differences in the concentric hamstrings:quadriceps (H:Q) ratio among athletes in different sports at 3 velocities. Design and Setting: We measured the H:Q ratio of both knees using the Biodex Pro Isokinetic Device. Subjects: Eighty-one male and female collegiate athletes. Measurements: We performed analyses for sport, velocity, and side of body for each sex. To compare the means of the concentric H:Q ratios for mean peak torque and mean total work, a 2 × 3 × 4 mixed-factorial analysis of variance was computed for women and a 2 × 2 × 3 mixed-factorial analysis of variance was computed for men. Results: We observed no significant interactions for men and women for the concentric H:Q ratio for mean peak torque. There was a significant mean difference among velocity conditions and a significant difference for men with respect to velocity. No significant differences were found for side of body or sport. Conclusions: The H:Q ratio increased as velocity increased. No differences existed for the H:Q ratio for sport or side of body. PMID:12937479

  5. Anterior Cruciate Ligament Injury: Compensation during Gait using Hamstring Muscle Activity

    PubMed Central

    Catalfamo, Paola Formento; Aguiar, Gerardo; Curi, Jorge; Braidot, Ariel

    2010-01-01

    Previous research has shown that an increase in hamstring activation may compensate for anterior tibial transalation (ATT) in patients with anterior cruciate ligament deficient knee (ACLd); however, the effects of this compensation still remain unclear. The goals of this study were to quantify the activation of the hamstring muscles needed to compensate the ATT in ACLd knee during the complete gait cycle and to evaluate the effect of this compensation on quadriceps activation and joint contact forces. A two dimensional model of the knee was used, which included the tibiofemoral and patellofemoral joints, knee ligaments, the medial capsule and two muscles units. Simulations were conducted to determine the ATT in healthy and ACLd knee and the hamstring activation needed to correct the abnormal ATT to normal levels (100% compensation) and to 50% compensation. Then, the quadriceps activation and the joint contact forces were calculated. Results showed that 100% compensation would require hamstring and quadriceps activations larger than their maximum isometric force, and would generate an increment in the peak contact force at the tibiofemoral (115%) and patellofemoral (48%) joint with respect to the healthy knee. On the other hand, 50% compensation would require less force generated by the muscles (less than 0.85 of maximum isometric force) and smaller contact forces (peak tibiofemoral contact force increased 23% and peak patellofemoral contact force decreased 7.5% with respect to the healthy knee). Total compensation of ATT by means of increased hamstring activity is possible; however, partial compensation represents a less deleterious strategy. PMID:20721326

  6. Comparative study of hamstring and quadriceps strengthening treatments in the management of knee osteoarthritis.

    PubMed

    Al-Johani, Ahmed H; Kachanathu, Shaji John; Ramadan Hafez, Ashraf; Al-Ahaideb, Abdulaziz; Algarni, Abdulrahman D; Meshari Alroumi, Abdulmohesn; Alanezi, Aqeel M

    2014-06-01

    [Purpose] Osteoarthritis (OA) of the knee is the most common form of joint disease. It is one of the major causes of impaired function that reduces quality of life (QOL) worldwide. The purpose of this study was to compare exercise treatments for hamstring and quadriceps strength in the management of knee osteoarthritis. [Subjects and Methods] Forty patients with OA knee, aged 50-65 years were divided into 2 groups. The first group (57.65±4.78 years) received hot packs and performed strengthening exercises for the quadriceps and hamstring, and stretching exercises for the hamstring. The second group (58.15±5.11 years) received hot packs and performed strengthening exercises for only the quadriceps, and stretching exercise for the hamstring. Outcome measures were the WOMAC (Western Ontario and McMaster Universities OA index questionnaire), Visual Analogue Scale (VAS) assessment of pain, the Fifty-Foot Walk Test (FWS), and Handheld dynamometry. [Results] There was a significant difference between the groups. The first group showed a more significant result than the second group. [Conclusion] Strengthening of the hamstrings in addition to strengthening of the quadriceps was shown to be beneficial for improving subjective knee pain, range of motion and decreasing the limitation of functional performance of patients with knee osteoarthritis. PMID:25013274

  7. Individual Muscle use in Hamstring Exercises by Soccer Players Assessed using Functional MRI.

    PubMed

    Fernandez-Gonzalo, R; Tesch, P A; Linnehan, R M; Kreider, R B; Di Salvo, V; Suarez-Arrones, L; Alomar, X; Mendez-Villanueva, A; Rodas, G

    2016-06-01

    This study used functional magnetic resonance imaging (fMRI) to compare individual muscle use in exercises aimed at preventing hamstring injuries. Thirty-six professional soccer players were randomized into 4 groups, each performing either Nordic hamstring, flywheel leg curl, Russian belt or conic-pulley exercise. MRIs were performed before and immediately after a bout of 4 sets of 8 repetitions. Pre-post exercise differences in contrast shift (T2) were analyzed for the long (BFLh) and short head (BFSh) of biceps femoris, semitendinosus (ST), semimembranosus (SM) and gracilis (GR) muscles. Flywheel leg curl increased (P<0.001) T2 of GR (95%), ST (65%), BFSh (51%) and BFLh (14%). After the Nordic hamstring, GR (39%), ST (16%) and BFSh (14%) showed increased T2 (P<0.001). Russian belt and conic-pulley exercise produced subtle (P<0.02) T2 increases of ST (9 and 6%, respectively) and BFLh (7 and 6%, respectively). Russian belt increased T2 of SM (7%). Among exercises examined, flywheel leg curl showed the most substantial hamstring and GR muscle use. However, no single exercise executed was able to increase T2 of all hamstring and synergist muscles analyzed. It is therefore suggested that multiple exercises must be carried out to bring in, and fully activate all knee flexors and hip extensors. PMID:27116347

  8. Fatigue effects on quadriceps and hamstrings activation in dancers performing drop landings.

    PubMed

    McEldowney, Kasey M; Hopper, Luke S; Etlin-Stein, Hannah; Redding, Emma

    2013-09-01

    Fatigue may reduce a dancer's ability to maintain the muscle synergies required for stable human movement. Therefore, fatigue presents as a potential risk factor for injury in dancers. Activation patterns of the quadriceps and hamstrings muscle groups in athletic populations have been consistently reported to alter in response to fatigue during landing tasks. It is unknown whether dancers demonstrate similar muscle activation patterns, nor if dancers respond to fatiguing protocols, with regard to muscle activation, in the same manner as their athletic counter-parts. The purpose of this study was to assess quadriceps and hamstrings activation levels in a cohort of dancers performing drop landings before and after completion of a dance-specific fatigue protocol, the High Intensity Dance Performance Fitness Test. Quadriceps and hamstrings co-contraction ratios significantly increased between pre- and post-fatigue conditions in a similar fashion to that reported in the literature. Therefore, the neuromuscular activation of the knee extensors and flexors in dancers changed in response to the dance-specific fatiguing protocol. Furthermore, quadriceps and hamstrings co-contraction ratios were substantially greater than previously reported in other athletic populations, due to low hamstrings activation levels. Future investigation of dancer biomechanical adaptations to fatigue would be beneficial to further examine the potential implications for injury risk. PMID:24069945

  9. Management of Extensor Tendon Injuries

    PubMed Central

    Griffin, M; Hindocha, S; Jordan, D; Saleh, M; Khan, W

    2012-01-01

    Extensor tendon injuries are very common injuries, which inappropriately treated can cause severe lasting impairment for the patient. Assessment and management of flexor tendon injuries has been widely reviewed, unlike extensor injuries. It is clear from the literature that extensor tendon repair should be undertaken immediately but the exact approach depends on the extensor zone. Zone I injuries otherwise known as mallet injuries are often closed and treated with immobilisaton and conservative management where possible. Zone II injuries are again conservatively managed with splinting. Closed Zone III or ‘boutonniere’ injuries are managed conservatively unless there is evidence of displaced avulsion fractures at the base of the middle phalanx, axial and lateral instability of the PIPJ associated with loss of active or passive extension of the joint or failed non-operative treatment. Open zone III injuries are often treated surgically unless splinting enable the tendons to come together. Zone V injuries, are human bites until proven otherwise requires primary tendon repair after irrigation. Zone VI injuries are close to the thin paratendon and thin subcutaneous tissue which strong core type sutures and then splinting should be placed in extension for 4-6 weeks. Complete lacerations to zone IV and VII involve surgical primary repair followed by 6 weeks of splinting in extension. Zone VIII require multiple figure of eight sutures to repair the muscle bellies and static immobilisation of the wrist in 45 degrees of extension. To date there is little literature documenting the quality of repairing extensor tendon injuries however loss of flexion due to extensor tendon shortening, loss of flexion and extension resulting from adhesions and weakened grip can occur after surgery. This review aims to provide a systematic examination method for assessing extensor injuries, presentation and management of all type of extensor tendon injuries as well as guidance on

  10. Hyaluronic acid and tendon lesions

    PubMed Central

    Kaux, Jean-François; Samson, Antoine; Crielaard, Jean-Michel

    2015-01-01

    Summary Introduction recently, the viscoelastic properties of hyaluronic acid (HA) on liquid connective tissue have been proposed for the treatment of tendinopathies. Some fundamental studies show encouraging results on hyaluronic acid’s ability to promote tendon gliding and reduce adhesion as well as to improve tendon architectural organisation. Some observations also support its use in a clinical setting to improve pain and function. This literature review analyses studies relating to the use of hyaluronic acid in the treatment of tendinopathies. Methods this review was constructed using the Medline database via Pubmed, Scopus and Google Scholar. The key words hyaluronic acid, tendon and tendinopathy were used for the research. Results in total, 28 articles (in English and French) on the application of hyaluronic acid to tendons were selected for their relevance and scientific quality, including 13 for the in vitro part, 7 for the in vivo animal part and 8 for the human section. Conclusions preclinical studies demonstrate encouraging results: HA permits tendon gliding, reduces adhesions, creates better tendon architectural organisation and limits inflammation. These laboratory observations appear to be supported by limited but encouraging short-term clinical results on pain and function. However, controlled randomised studies are still needed. PMID:26958533

  11. Effect of Varying Hamstring Tension on Anterior Cruciate Ligament Strain During in Vitro Impulsive Knee Flexion and Compression Loading

    PubMed Central

    Withrow, Thomas J.; Huston, Laura J.; Wojtys, Edward M.; Ashton-Miller, James A.

    2008-01-01

    Background: The hamstring muscles are well positioned to limit both anterior tibial translation and anterior cruciate ligament strain during the knee flexion phase of a jump landing. We hypothesized that systematically increasing or decreasing hamstring tension during the knee flexion phase of a simulated jump landing would significantly affect peak relative strain in the anterior cruciate ligament. Methods: Ten cadaveric knees from four male and six female donors (mean age [and standard deviation] at the time of death, 60.3 ± 23.6 years) were mounted in a custom fixture to initially position the specimen in 25° of knee flexion and simulate axial impulsive loading averaging 1700 N to cause an increase in knee flexion. Quadriceps, hamstring, and gastrocnemius muscle forces were simulated with use of pretensioned linear springs, with the tension in the hamstrings arranged to be increased, held constant, decreased, at “baseline,” or absent during knee flexion. Impulsive loading applied along the tibia and femur was monitored with use of triaxial load transducers, while uniaxial load cells monitored quadriceps and medial and lateral hamstring forces. Relative strain in the anterior cruciate ligament was measured with use of a differential variable reluctance transducer, and tibiofemoral kinematics were measured optoelectronically. For each specimen, anterior cruciate ligament strains were recorded over eighty impact trials: ten preconditioning trials, ten “baseline” trials involving decreasing hamstring tension performed before and after three sets of ten trials conducted with increasing hamstring tension, constant hamstring tension, or no hamstring tension. Peak relative strains in the anterior cruciate ligament were normalized for comparison across specimens. Results: Increasing hamstring force during the knee flexion landing phase decreased the peak relative strain in the anterior cruciate ligament by >70% compared with the baseline condition (p = 0

  12. Dry Endoscopic-Assisted Mini-Open Approach With Neuromonitoring for Chronic Hamstring Avulsions and Ischial Tunnel Syndrome

    PubMed Central

    Gómez-Hoyos, Juan; Reddy, Manoj; Martin, Hal D.

    2015-01-01

    Chronic hamstring origin avulsions and ischial tunnel syndrome are common causes of posterior hip pain. Although physical therapy has shown benefits in some cases, recent evidence has reported better outcomes with surgical treatment in appropriately selected patients. The full-open approach has been the classic procedure to address this problem. However, the complications related to extensive tissue exposure and the proximity of the incision to the perianal zone have led to the description of full-endoscopic techniques. Achieving an accurate hamstring repair could be technically demanding with a full-endoscopic procedure. Accurate reattachment is crucial in hamstring repair because of the functional demand of the muscles crossing of 2 major joints (hip and knee). This surgical note describes a mixed technique including a mini-open approach, neuromonitoring, and dry endoscopic-assisted repair of the hamstring origin as an alternative for treating patients with chronic hamstring avulsions and ischial tunnel syndrome that remain symptomatic despite nonoperative treatment. PMID:26258031

  13. The correlation between the imaging characteristics of hamstring injury and time required before returning to sports: a literature review

    PubMed Central

    Svensson, Kjell; Alricsson, Marie; Eckerman, Mattias; Magounakis, Theofilos; Werner, Suzanne

    2016-01-01

    Injuries to the hamstring muscles are common in athletes. Track and field, Australian football, American football and soccer are examples of sports where hamstring injuries are the most common. The purpose of this study was to investigate whether there is a correlation between a hamstring injury prognosis and its characteristics of imaging parameters. The literature search was performed in the databases PubMed and CINAHL, and eleven articles were included. Seven out of the 11 articles showed a correlation between the size of the hamstring injury and length of time required before returning to sports. Different authors have reported contrasting results about length of time required before returning to sports due to location of injury within specific muscle. Majority of the articles found hamstring strain correlated to an extended amount of time required before returning to sports. PMID:27419106

  14. The correlation between the imaging characteristics of hamstring injury and time required before returning to sports: a literature review.

    PubMed

    Svensson, Kjell; Alricsson, Marie; Eckerman, Mattias; Magounakis, Theofilos; Werner, Suzanne

    2016-06-01

    Injuries to the hamstring muscles are common in athletes. Track and field, Australian football, American football and soccer are examples of sports where hamstring injuries are the most common. The purpose of this study was to investigate whether there is a correlation between a hamstring injury prognosis and its characteristics of imaging parameters. The literature search was performed in the databases PubMed and CINAHL, and eleven articles were included. Seven out of the 11 articles showed a correlation between the size of the hamstring injury and length of time required before returning to sports. Different authors have reported contrasting results about length of time required before returning to sports due to location of injury within specific muscle. Majority of the articles found hamstring strain correlated to an extended amount of time required before returning to sports. PMID:27419106

  15. The effects of a Feldenkrais program and relaxation procedures on hamstring length.

    PubMed

    James, Michelle; Kolt, Gregory; McConville, Janet; Bate, Patricia

    1998-01-01

    Despite the growing popularity of the Feldenkrais method in Australia (Wildman 1990b), little research is available investigating its efficacy. The current study investigated the effects of the Feldenkrais method on hamstring length. Forty-eight healthy undergraduate participants were randomly allocated into either Feldenkrais, relaxation, or control groups. All subjects had their right hamstring measured using a modified active knee extension test prior to the first session, prior to the fourth (final) session, and after the final session of intervention. Two-way analysis of variance with time of measurement repeated revealed no significant differences between the groups. The findings are discussed in relation to apparent ineffectiveness of the Feldenkrais Awareness Through Movement lessons used on hamstring length, exposure time to the technique, and attitudes towards the Feldenkrais method. PMID:11676714

  16. Tendon Transfers for Combined Peripheral Nerve Injuries.

    PubMed

    Makarewich, Christopher A; Hutchinson, Douglas T

    2016-08-01

    Combined peripheral nerve injuries present a unique set of challenges to the hand surgeon when considering tendon transfers. They are often associated with severe soft tissue trauma, including lacerations to remaining innervated muscles and tendons, significant scar formation, and substantial sensory loss. In the case of combined nerve injuries, there are typically fewer options for tendon transfers due to fewer tendons of shared function that are expendable as well as associated injuries to tendon or muscle bellies. As such, careful preoperative planning must be performed to make the most of remaining muscle tendon units. PMID:27387081

  17. Serial Changes of Quadriceps and Hamstring Muscle Strength Following Total Knee Arthroplasty: A Meta-Analysis

    PubMed Central

    Ahn, Hyeong-Sik; Lee, Dae-Hee

    2016-01-01

    This meta-analysis was performed to analyze serial changes in thigh muscles, including quadriceps and hamstring muscles, from before to one year after total knee arthroplasty (TKA). All studies sequentially comparing isokinetic quadriceps and hamstring muscle strengths between the TKA side and the contralateral uninjured limb were included in this meta-analysis. Five studies with 7 cohorts were included in this meta-analysis. The mean differences in the strengths of quadriceps and hamstring muscles between the TKA and uninjured sides were greatest three months after surgery (26.8 N∙m, 12.8 N∙m, P<0.001), but were similar to preoperative level at six months (18.4 N∙m, 7.4 N∙m P<0.001) and were maintained for up to one year (15.9 N∙m, 4.1 N∙m P<0.001). The pooled mean differences in changes in quadriceps and hamstring strengths relative to preoperative levels were 9.2 N∙m and 4.9 N∙m, respectively, three months postoperatively (P = 0.041), but were no longer significant after six months and one year. During the year after TKA, quadriceps and hamstring muscle strengths were lowest after 3 months, recovering to preoperative level after six months, but not reaching the muscle strength on the contralateral side. Relative to preoperative levels, the difference in muscle strength between the TKA and contralateral knees was only significant at three months. Because decrease of strength of the quadriceps was significantly greater than decrease in hamstring muscle strength at postoperative three months, early rehabilitation after TKA should focus on recovery of quadriceps muscle strength. PMID:26849808

  18. Achilles tendon rupture rehabilitation

    PubMed Central

    Kearney, R. S.; Parsons, N.; Underwood, M.; Costa, M. L.

    2015-01-01

    Objectives The evidence base to inform the management of Achilles tendon rupture is sparse. The objectives of this research were to establish what current practice is in the United Kingdom and explore clinicians’ views on proposed further research in this area. This study was registered with the ISRCTN (ISRCTN68273773) as part of a larger programme of research. Methods We report an online survey of current practice in the United Kingdom, approved by the British Orthopaedic Foot and Ankle Society and completed by 181 of its members. A total of ten of these respondents were invited for a subsequent one-to-one interview to explore clinician views on proposed further research in this area. Results The survey showed wide variations in practice, with patients being managed in plaster cast alone (13%), plaster cast followed by orthoses management (68%), and orthoses alone (19%). Within these categories, further variation existed regarding the individual rehabilitation facets, such as the length of time worn, the foot position within them and weight-bearing status. The subsequent interviews reflected this clinical uncertainty and the pressing need for definitive research. Conclusions The gap in evidence in this area has resulted in practice in the United Kingdom becoming varied and based on individual opinion. Future high-quality randomised trials on this subject are supported by the clinical community. Cite this article: Bone Joint Res 2015;4:65–9 PMID:25868938

  19. Bone Morphogenetic Protein 7 (BMP-7) Influences Tendon-Bone Integration In Vitro

    PubMed Central

    Schwarting, Tim; Lechler, Philipp; Struewer, Johannes; Ambrock, Marius; Frangen, Thomas Manfred; Ruchholtz, Steffen; Ziring, Ewgeni; Frink, Michael

    2015-01-01

    Introduction Successful graft ingrowth following reconstruction of the anterior cruciate ligament is governed by complex biological processes at the tendon-bone interface. The aim of this study was to investigate in an in vitro study the effects of bone morphogenetic protein 7 (BMP-7) on tendon-bone integration. Materials and Methods To study the biological effects of BMP-7 on the process of tendon-bone-integration, two independent in vitro models were used. The first model involved the mono- and coculture of bovine tendon specimens and primary bovine osteoblasts with and without BMP-7 exposure. The second model comprised the mono- and coculture of primary bovine osteoblasts and fibroblasts. Alkaline phosphatase (ALP), lactate dehydrogenase (LDH), lactate and osteocalcin (OCN) were analyzed by ELISA. Histological analysis and electron microscopy of the tendon specimens were performed. Results In both models, positive effects of BMP-7 on ALP enzyme activity were observed (p<0.001). Additionally, similar results were noted for LDH activity and lactate concentration. BMP-7 stimulation led to a significant increase in OCN expression. Whereas the effects of BMP-7 on tendon monoculture peaked during an early phase of the experiment (p<0.001), the cocultures showed a maximal increase during the later stages (p<0.001). The histological analysis showed a stimulating effect of BMP-7 on extracellular matrix formation. Organized ossification zones and calcium carbonate-like structures were only observed in the BMP-stimulated cell cultures. Discussion This study showed the positive effects of BMP-7 on the biological process of tendon-bone integration in vitro. Histological signs of improved mineralization were paralleled by increased rates of osteoblast-specific protein levels in primary bovine osteoblasts and fibroblasts. Conclusion Our findings indicated a role for BMP-7 as an adjuvant therapeutic agent in the treatment of ligamentous injuries, and they emphasized the

  20. Tendon Tissue Engineering and Its Role on Healing of the Experimentally Induced Large Tendon Defect Model in Rabbits: A Comprehensive In Vivo Study

    PubMed Central

    Meimandi-Parizi, Abdolhamid; Oryan, Ahmad; Moshiri, Ali

    2013-01-01

    Healing of large tendon defects is challenging. We studied the role of collagen implant with or without polydioxanone (PDS) sheath on the healing of a large Achilles tendon defect model, in rabbits. Sixty rabbits were divided into three groups. A 2 cm gap was created in the left Achilles tendon of all rabbits. In the control lesions, no implant was used. The other two groups were reconstructed by collagen and collagen-PDS implants respectively. The animals were clinically examined at weekly intervals and their lesions were observed by ultrasonography. Blood samples were obtained from the animals and were assessed for hematological analysis and determination of serum PDGF level, at 60 days post injury (DPI). The animals were then euthanized and their lesions were assessed for gross and histopathology, scanning electron microscopy, biomechanical testing, dry matter and hydroxyproline content. Another 65 pilot animals were also studied grossly and histopathologically to define the host implant interaction and graft incorporation at serial time points. The treated animals gained significantly better clinical scoring compared to the controls. Treatment with collagen and collagen-PDS implants significantly increased the biomechanical properties of the lesions compared to the control tendons at 60DPI (P<0.05). The tissue engineered implants also reduced peritendinous adhesion, muscle fibrosis and atrophy, and increased ultrasonographical echogenicity and homogenicity, maturation and differentiation of the collagen fibrils and fibers, tissue alignment and volume of the regenerated tissue compared to those of the control lesions (P<0.05). The implants were gradually absorbed and substituted by the new tendon. Implantation of the bioimplants had a significant role in initiating tendon healing and the implants were biocompatible, biodegradable and safe for application in tendon reconstructive surgery. The results of the present study may be valuable in clinical practice. PMID

  1. Common Disorders of the Achilles Tendon

    MedlinePlus

    ... stress on the tendon too quickly, leading to micro-injury of the tendon fibers. Due to this ... with over-pronation or gait abnormalities, custom orthotic devices may be prescribed. Night splints. Night splints help ...

  2. Bone Grafts

    MedlinePlus

    ... repair and rebuild diseased bones in your hips, knees, spine, and sometimes other bones and joints. Grafts can also repair bone loss caused by some types of fractures or cancers. Once your body accepts the bone ...

  3. Madelung Deformity and Extensor Tendon Rupture.

    PubMed

    Shahcheraghi, Gholam Hossain; Peyman, Maryam; Mozafarian, Kamran

    2015-07-01

    Extensor tendon rupture in chronic Madelung deformity, as a result of tendon attrition on the dislocated distal ulna, is a rare occurrence. It is, however, seen more often in rheumatoid arthritis. There are few case reports in the English-language literature on this issue. We report a case of multiple tendon ruptures in a previously undiagnosed Madelung deformity. PMID:26161772

  4. Rerouting extensor pollicis longus tendon transfer.

    PubMed

    Colantoni Woodside, Julie; Bindra, Randip R

    2015-04-01

    Following radial nerve palsy, loss of the extensor pollicis longus (EPL), abductor pollicis longus and extensor pollicis brevis tendons results in loss of thumb extension and radial abduction. Multiple tendon transfers are described to address the loss of thumb extension following radial palsy utilizing the palmaris longus or flexor digitorum sublimis transferred to the EPL tendon. Owing to its ulnar vector of pull, the EPL tendon is a secondary adductor of the thumb, and in order to mitigate the tendency for thumb adduction, the EPL tendon is divided at the wrist and brought subcutaneously to the radial side of the wrist for repair to the donor tendon to improve the line of pull for the donor tendon. We describe the use of a technique to reroute the EPL tendon through the first compartment in a retrograde fashion prior to repair with the donor tendon on the radial side of the wrist. The use of the first dorsal compartment provides a pulley to maintain the position of the transfer and to prevent potential bowstringing of the tendon as wrist flexion and thumb extension are attempted. because the repair is performed proximal to the extensor retinaculum, the donor tendon length is not compromised. Because the tendon is redirected through the first dorsal compartment and inserts into the distal phalanx, a single transfer attempts to restores both thumb extension and radial abduction. PMID:25746145

  5. Tenascin-C and human tendon degeneration.

    PubMed Central

    Riley, G. P.; Harrall, R. L.; Cawston, T. E.; Hazleman, B. L.; Mackie, E. J.

    1996-01-01

    We investigated the distribution of tenascin in supraspinatus tendons to determine whether an alteration in tenascin expression was associated with human tendon degeneration. Tenascin was present in all of the tendons studied, although with two distinct patterns of expression. First, tenascin was associated with organized, fibrous regions of the tendon matrix that were typical of the normal tendon structure. This distribution is consistent with a role for tenascin in collagen fibril organization, perhaps maintaining the interface between fibrils and adjacent structures. Second, although tenascin was generally absent from poorly organized matrix in degenerate tendons, it was strongly associated with some rounded cells in disorganized fibrocartilaginous regions that were more abundant in pathological specimens. Tenascin was also found around infiltrating blood vessels, with more intense staining associated with a mononuclear cell infiltrate. Western blotting of tendon extracts showed differences in tenascin isoform expression, with only the small (200-kd) tenascin isoform found in normal tendons. Degenerate tendons also expressed the 300-kd isoform, consistent with a role for the larger tenascin isoform in tendon disease, potentially stimulating tenocyte proliferation, cell rounding, and fibrocartilaginous change. Proteolytic fragments of tenascin were detected but only in ruptured tendons, an indication of matrix remodeling in degenerate tendons, with fragment sizes consistent with the activity of matrix metalloproteinase enzymes. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:8780397

  6. Agreement Between Face-to-Face and Free Software Video Analysis for Assessing Hamstring Flexibility in Adolescents.

    PubMed

    Moral-Muñoz, José A; Esteban-Moreno, Bernabé; Arroyo-Morales, Manuel; Cobo, Manuel J; Herrera-Viedma, Enrique

    2015-09-01

    The objective of this study was to determine the level of agreement between face-to-face hamstring flexibility measurements and free software video analysis in adolescents. Reduced hamstring flexibility is common in adolescents (75% of boys and 35% of girls aged 10). The length of the hamstring muscle has an important role in both the effectiveness and the efficiency of basic human movements, and reduced hamstring flexibility is related to various musculoskeletal conditions. There are various approaches to measuring hamstring flexibility with high reliability; the most commonly used approaches in the scientific literature are the sit-and-reach test, hip joint angle (HJA), and active knee extension. The assessment of hamstring flexibility using video analysis could help with adolescent flexibility follow-up. Fifty-four adolescents from a local school participated in a descriptive study of repeated measures using a crossover design. Active knee extension and HJA were measured with an inclinometer and were simultaneously recorded with a video camera. Each video was downloaded to a computer and subsequently analyzed using Kinovea 0.8.15, a free software application for movement analysis. All outcome measures showed reliability estimates with α > 0.90. The lowest reliability was obtained for HJA (α = 0.91). The preliminary findings support the use of a free software tool for assessing hamstring flexibility, offering health professionals a useful tool for adolescent flexibility follow-up. PMID:26313580

  7. Immediate effect of passive and active stretching on hamstrings flexibility: a single-blinded randomized control trial

    PubMed Central

    Nishikawa, Yuichi; Aizawa, Junya; Kanemura, Naohiko; Takahashi, Tetsuya; Hosomi, Naohisa; Maruyama, Hirofumi; Kimura, Hiroaki; Matsumoto, Masayasu; Takayanagi, Kiyomi

    2015-01-01

    [Purpose] This study compared the efficacy of passive and active stretching techniques on hamstring flexibility. [Subjects] Fifty-four healthy young subjects were randomly assigned to one of three groups (2 treatment groups and 1 control group). [Methods] Subjects in the passive stretching group had their knees extended by an examiner while lying supine 90° of hip flexion. In the same position, subjects in the active stretching group extended their knees. The groups performed 3 sets of the assigned stretch, with each stretch held for 10 seconds at the point where tightness in the hamstring muscles was felt. Subjects in the control group did not perform stretching. Before and immediately after stretching, hamstring flexibility was assessed by a blinded assessor, using the active knee-extension test. [Results] After stretching, there was a significant improvement in the hamstring flexibilities of the active and passive stretching groups compared with the control group. Furthermore, the passive stretching group showed significantly greater improvement in hamstring flexibility than the active stretching group. [Conclusion] Improvement in hamstring flexibility measured by the active knee-extension test was achieved by both stretching techniques; however, passive stretching was more effective than active stretching at achieving an immediate increase in hamstring flexibility. PMID:26644667

  8. Achilles tendon reflex measuring system

    NASA Astrophysics Data System (ADS)

    Szebeszczyk, Janina; Straszecka, Joanna

    1995-06-01

    The examination of Achilles tendon reflex is widely used as a simple, noninvasive clinical test in diagnosis and pharmacological therapy monitoring in such diseases as: hypothyroidism, hyperthyroidism, diabetic neuropathy, the lower limbs obstructive angiopathies and intermittent claudication. Presented Achilles tendon reflect measuring system is based on the piezoresistive sensor connected with the cylinder-piston system. To determinate the moment of Achilles tendon stimulation a detecting circuit was used. The outputs of the measuring system are connected to the PC-based data acquisition board. Experimental results showed that the measurement accuracy and repeatability is good enough for diagnostics and therapy monitoring purposes. A user friendly, easy-to-operate measurement system fulfills all the requirements related to recording, presentation and storing of the patients' reflexograms.

  9. Excellent reliability for MRI grading and prognostic parameters in acute hamstring injuries

    PubMed Central

    Hamilton, B; Whiteley, R; Almusa, E; Roger, B; Geertsema, C; Tol, Johannes L

    2014-01-01

    Background Categorical grading and other measurable MRI parameters are frequently utilised for predicting the outcome of hamstring injuries. However, the reliability and smallest detectable difference (SDD) have not been previously evaluated. It therefore remains unclear if the variability in previously reported results reflects reporting variation or actual injury status. Methods 25 hamstring injuries were scored by two experienced radiologists using the Peetrons grading and specific prognostic MRI parameters: distance from ischial tuberosity (cm), extent (cranio to caudal, anterior to posterior, medial to lateral; (cm)), maximum cross-sectional area (%), volume (cm3) of the oedema. The interobserver and intraobserver reliability was calculated along with the SDDs for each scale variable. Results There were 3 Grade 0 (12%), 11 grade 1 (44%), 9 grade 2 (36%) and 2 grade 3 (8%) injuries. Cronbach's α values for grading were 1.00 (inter) and 0.96 (intra), respectively. The intraclass correlation coefficients for the prognostic MRI parameters were between 0.77 and 1.0. The SDDs varied between each parameter. Conclusions Excellent interobserver and intraobserver reliability was found for grading and prognostic MRI parameters in acute hamstring injuries. In daily practice and research, we can be confident that scoring hamstring injuries by experienced radiologists is reproducible. The documented SDDs allow meaningful clinical inferences to be made when assessing observed and reported changes in MRI status. PMID:24037670

  10. Platelet-rich plasma (PRP) treatment of sports-related severe acute hamstring injuries

    PubMed Central

    Guillodo, Yannick; Madouas, Gwénaelle; Simon, Thomas; Le Dauphin, Hermine; Saraux, Alain

    2015-01-01

    Summary Purpose hamstring injury is the most common musculoskeletal disorder and one of the main causes of missed sporting events. Shortening the time to return to play (TTRTP) is a priority for athletes and sports medicine practitioners. Hypothesis platelet-rich plasma (PRP) injection at the site of severe acute hamstring injury increases the healing rate and shortens the TTRTP. Study design Cohort study. Methods all patients with ultrasonography and MRI evidence of severe acute hamstring injury between January 2012 and March 2014 were offered PRP treatment. Those who accepted received a single intramuscular PRP injection within 8 days post-injury; the other patients served as controls. The same standardized rehabilitation program was used in both groups. A physical examination and ultrasonography were performed 10 and 30 days post-injury, then a phone interview 120 days post-injury, to determine the TTRTP at the pre-injury level. Results of 34 patients, 15 received PRP and 19 did not. Mean TTRTP at the pre-injury level was 50.9±10.7 days in the PRP group and 52.8±15.7 days in the control group. The difference was not statistically significant. Conclusion a single intramuscular PRP injection did not shorten the TTRTP in sports people with severe acute hamstring injuries. PMID:26958537

  11. Single-Stage Reconstruction of Achilles Tendon and Overlying Tissue With the Extended Temporoparietal Fasciagaleal Flap-23-Year Follow-Up and the Review of the Literature.

    PubMed

    Dobke, Marek; Suliman, Ahmed; Mackert, Gina A; Herrera, Fernando A; Singer, Robert; Nelson, Jeffrey

    2016-05-01

    In the absence of an established "gold standard" for complex Achilles tendon and regional soft tissue defect reconstruction, many techniques have been advocated. Two cases describing a novel technique of successful repair with the review of literature are presented. The underlying problem consisted of Achilles tendon necrosis with local inflammation in the first case and tendon contracture with foot malposition due to a burn injury in the other. Each patient, upon debridement, had a 6-cm Achilles tendon defect with associated overlying soft tissue deficits reconstructed with an extended temporoparietal fasciagaleal flap and a split thickness skin graft. Both cases highlight the successful functional and aesthetic quality as well as the durability of concurrent vascularized tendon and soft tissue replacement and coverage in 2 distinct clinical scenarios. PMID:27070674

  12. Ligament reconstruction with tendon interposition using an acellular dermal allograft for thumb carpometacarpal arthritis.

    PubMed

    Kokkalis, Zinon T; Zanaros, George; Sotereanos, Dean G

    2009-03-01

    Ligament reconstruction tendon interposition arthroplasty is currently the preferred technique for carpometacarpal joint arthritis of the thumb by most surgeons. Despite its efficacy, morbidity has been associated with the harvest of the flexor carpi radialis tendon. Using an allograft as material for arthroplasty, donor site morbidity is avoided. In this report, we present our surgical technique to perform ligament reconstruction tendon interposition arthroplasty using an acellular dermal matrix allograft (GraftJacket) in patients with Eaton stages II, III, and IV symptomatic first carpometacarpal arthritis.One hundred thumbs with trapeziometacarpal osteoarthritis underwent surgical treatment using GraftJacket allograft instead of the flexor carpi radialis tendon autograft. Each patient was followed for a minimum of 12 months. The surgical procedure included trapezial excision and identification of the flexor carpi radialis. The allograft was cut to create a 15-cm strip. The ligament reconstruction was performed by passing the strip around the flexor carpi radialis tendon and suturing it to the base of the thumb metacarpal base through an intramedullary drill hole. The remaining portion of the allograft was fashioned as an interposition mass (anchovy) and interposed between the scaphoid and the base of the first metacarpal.All but 1 patient experienced significant improvement in his or her pain scale rating and grip and pinch strengths. Outcomes from this study compare very favorably with those of other series. No patients experienced a foreign body reaction or infection in this series. We believe that the use of an acellular dermal allograft for both ligament reconstruction and tendon interposition provides a safe and an effective alternative technique for the treatment of advanced first carpometacarpal arthritis. PMID:19276927

  13. Biochemical, histologic, and biomechanical characterization of native and decellularized flexor tendon specimens harvested from the pelvic limbs of orthopedically normal dogs.

    PubMed

    Balogh, Daniel G; Biskup, Jeffery J; O'Sullivan, M Gerard; Scott, Ruth M; Groschen, Donna; Evans, Richard B; Conzemius, Michael G

    2016-04-01

    OBJECTIVE To evaluate the biochemical and biomechanical properties of native and decellularized superficial digital flexor tendons (SDFTs) and deep digital flexor tendons (DDFTs) harvested from the pelvic limbs of orthopedically normal dogs. SAMPLE 22 commercially supplied tendon specimens (10 SDFT and 12 DDFT) harvested from the pelvic limbs of 13 canine cadavers. PROCEDURES DNA, glycosaminoglycan, collagen, and protein content were measured to biochemically compare native and decellularized SDFT and DDFT specimens. Mechanical testing was performed on 4 groups consisting of native tendons (5 SDFTs and 6 DDFTs) and decellularized tendons (5 SDFTs and 6 DDFTs). All tendons were preconditioned, and tension was applied to failure at 0.5 mm/s. Failure mode was video recorded for each tendon. Load-deformation and stress-strain curves were generated; calculations were performed to determine the Young modulus and stiffness. Biochemical and biomechanical data were statistically compared by use of the Wilcoxon rank sum test. RESULTS Decellularized SDFT and DDFT specimens had significantly less DNA content than did native tendons. No significant differences were identified between native and decellularized specimens with respect to glycosaminoglycan, collagen, or protein content. Biomechanical comparison yielded no significant intra- or intergroup differences. All DDFT constructs failed at the tendon-clamp interface, whereas nearly half (4/10) of the SDFT constructs failed at midsubstance. CONCLUSIONS AND CLINICAL RELEVANCE Decellularized commercial canine SDFT and DDFT specimens had similar biomechanical properties, compared with each other and with native tendons. The decellularization process significantly decreased DNA content while minimizing loss of extracellular matrix components. Decellularized canine flexor tendons may provide suitable, biocompatible graft scaffolds for bioengineering applications such as tendon or ligament repair. PMID:27027838

  14. Tibialis Anterior Tendon Transfer for Posterior Tibial Tendon Insufficiency.

    PubMed

    Ramanujam, Crystal L; Stapleton, John J; Zgonis, Thomas

    2016-01-01

    The Cobb procedure is useful for addressing stage 2 posterior tibial tendon dysfunction and is often accompanied by a medial displacement calcaneal osteotomy and/or lateral column lengthening. The Cobb procedure can also be combined with selected medial column arthrodesis and realignment osteotomies along with equinus correction when indicated. PMID:26590721

  15. MRI-Based Regional Muscle Use during Hamstring Strengthening Exercises in Elite Soccer Players.

    PubMed

    Mendez-Villanueva, Alberto; Suarez-Arrones, Luis; Rodas, Gil; Fernandez-Gonzalo, Rodrigo; Tesch, Per; Linnehan, Richard; Kreider, Richard; Di Salvo, Valter

    2016-01-01

    The present study examined site-specific hamstring muscles use with functional magnetic resonance imaging (MRI) in elite soccer players during strength training. Thirty-six players were randomized into four groups, each performing either Nordic hamstring, flywheel leg-curl, Russian belt or the hip-extension conic-pulley exercise. The transverse relaxation time (T2) shift from pre- to post-MRI were calculated for the biceps femoris long (BFl) and short (BFs) heads, semitendinosus (ST) and semimembranosus (SM) muscles at proximal, middle and distal areas of the muscle length. T2 values increased substantially after flywheel leg-curl in all regions of the BFl (from 9±8 to 16±8%), BFs (41±6-71±11%), and ST (60±1-69±7%). Nordic hamstring induced a substantial T2 increase in all regions of the BFs (13±8-16±5%) and ST (15±7-17±5%). T2 values after the Russian belt deadlift substantially increased in all regions of the BFl (6±4-7±5%), ST (8±3-11±2%), SM (6±4-10±4%), and proximal and distal regions of BFs (6±6-8±5%). T2 values substantially increased after hip-extension conic-pulley only in proximal and middle regions of BFl (11±5-7±5%) and ST (7±3-12±4%). The relevance of such MRI-based inter- and intra-muscle use in designing more effective resistance training for improving hamstring function and preventing hamstring injuries in elite soccer players should be explored with more mechanistic studies. PMID:27583444

  16. MRI observations at return to play of clinically recovered hamstring injuries

    PubMed Central

    Reurink, Gustaaf; Goudswaard, Gert Jan; Tol, Johannes L; Almusa, Emad; Moen, Maarten H; Weir, Adam; Verhaar, Jan A N; Hamilton, Bruce; Maas, Mario

    2014-01-01

    Background Previous studies have shown that MRI of fresh hamstring injuries have diagnostic and prognostic value. The clinical relevance of MRI at return to play (RTP) has not been clarified yet. The aim of this study is to describe MRI findings of clinically recovered hamstring injuries in amateur, elite and professional athletes that were cleared for RTP. Methods We obtained MRI of 53 consecutive athletes with hamstring injuries within 5 days of injury and within 3 days of RTP. We assessed the following parameters: injured muscle, grading of injury, presence and extent of intramuscular signal abnormality. We recorded reinjuries within 2 months of RTP. Results MRIs of the initial injury showed 27 (51%) grade 1 and 26 (49%) grade 2 injuries. Median time to RTP was 28 days (range 12–76). On MRI at RTP 47 athletes (89%) had intramuscular increased signal intensity on fluid-sensitive sequences with a mean longitudinal length of 77 mm (±53) and a median cross-sectional area of 8% (range 0–90%) of the total muscle area. In 22 athletes (42%) there was abnormal intramuscular low-signal intensity. We recorded five reinjuries. Conclusions 89% of the clinically recovered hamstring injuries showed intramuscular increased signal intensity on fluid-sensitive sequences on MRI. Normalisation of this increased signal intensity seems not required for a successful RTP. Low-signal intensity suggestive of newly developed fibrous tissues is observed in one-third of the clinically recovered hamstring injuries on MRI at RTP, but its clinical relevance and possible association with increased reinjury risk has to be determined. PMID:24255767

  17. Dynamic soft tissue mobilisation increases hamstring flexibility in healthy male subjects

    PubMed Central

    Hopper, D; Deacon, S; Das, S; Jain, A; Riddell, D; Hall, T; Briffa, K; Vicenzino, B.

    2005-01-01

    Objectives: The purpose of this study was to investigate the effect of dynamic soft tissue mobilisation (STM) on hamstring flexibility in healthy male subjects. Methods: Forty five males volunteered to participate in a randomised, controlled single blind design study. Volunteers were randomised to either control, classic STM, or dynamic STM intervention. The control group was positioned prone for 5 min. The classic STM group received standard STM techniques performed in a neutral prone position for 5 min. The dynamic STM group received all elements of classic STM followed by distal to proximal longitudinal strokes performed during passive, active, and eccentric loading of the hamstring. Only specific areas of tissue tightness were treated during the dynamic phase. Hamstring flexibility was quantified as hip flexion angle (HFA) which was the difference between the total range of straight leg raise and the range of pelvic rotation. Pre- and post-testing was conducted for the subjects in each group. A one-way ANCOVA followed by pairwise post-hoc comparisons was used to determine whether change in HFA differed between groups. The α level was set at 0.05. Results: Increase in hamstring flexibility was significantly greater in the dynamic STM group than either the control or classic STM groups with mean (standard deviation) increase in degrees in the HFA measures of 4.7 (4.8), –0.04 (4.8), and 1.3 (3.8), respectively. Conclusions: Dynamic soft tissue mobilisation (STM) significantly increased hamstring flexibility in healthy male subjects. PMID:16118294

  18. Tendon Ruptures Associated With Corticosteroid Therapy

    PubMed Central

    Halpern, Alan A.; Horowitz, Bruce G.; Nagel, Donald A.

    1977-01-01

    In five patients, tendon ruptures occurred in association with corticosteroid therapy, either systemic or local infiltration. The chronic nature of the pain in all of these patients suggests that what we often call tendinitis may in fact be early or partial ruptures of tendons. Patients who receive local infiltration of corticosteroids should perhaps be advised of the risk of a ruptured tendon. In addition, particularly when the Achilles tendon is involved, immobilization should be utilized initially for a presumed tendinitis or early rupture, to protect the tendon from further injury. ImagesFigure 1.Figure 2. PMID:919538

  19. Kienbock’s Disease treated with Interposition Arthroplasty using Ipsilateral Palmaris Longus Tendon and Muscle Belly

    PubMed Central

    Dutta, Anshuman; Sipani, Arun Kumar; Agarwala, Vikash; Srikanth, Mudiganty

    2012-01-01

    Introduction: Kienbock’s disease is an osteonecrosis of lunate bone (lunatomalacia) seen more commonly in males in the second to fourth decade of life. The exact etiology is unknown and symptoms include wrist pain and stiffness of wrist. Advanced stages of disease may require lunate excision and filling of the void by various substitutes like silicone implants, tendon grafts etc. We report a case of Kienbock’s disease with lunate excision and filling of defect by coiled palmaris longus muscle and tendon unit. Case Report: An 18 year old male student presented with progressive wrist pain and difficulty in wrist movements. Investigations revealed a diagnosis of grade 4 Kienbock’s disease. Lunate excision by a palmar approach followed by interposition arthroplasty with ipsilateral coiled Palmaris longus muscle belly along with the tendon was done under regional anaesthesia. Nine months post-operatively patient is pain free and wrist movements are full and free. Conclusion: In advanced stages of Keinbock’s disease lunate excision surgery is recommended. Post excision void can be filled with coiled Palmaris longus tendon-muscle unit together to increase the volume of the graft. This achieves snug fit, avoids the need of internal fixation, and also prevent carpal collapse. Our case shows good clinical outcome in short term with no carpal collapse by use of this procedure.

  20. Bioreactor Design for Tendon/Ligament Engineering

    PubMed Central

    Wang, Tao; Gardiner, Bruce S.; Lin, Zhen; Rubenson, Jonas; Kirk, Thomas B.; Wang, Allan; Xu, Jiake

    2013-01-01

    Tendon and ligament injury is a worldwide health problem, but the treatment options remain limited. Tendon and ligament engineering might provide an alternative tissue source for the surgical replacement of injured tendon. A bioreactor provides a controllable environment enabling the systematic study of specific biological, biochemical, and biomechanical requirements to design and manufacture engineered tendon/ligament tissue. Furthermore, the tendon/ligament bioreactor system can provide a suitable culture environment, which mimics the dynamics of the in vivo environment for tendon/ligament maturation. For clinical settings, bioreactors also have the advantages of less-contamination risk, high reproducibility of cell propagation by minimizing manual operation, and a consistent end product. In this review, we identify the key components, design preferences, and criteria that are required for the development of an ideal bioreactor for engineering tendons and ligaments. PMID:23072472

  1. The effects of test environment and cyclic stretching on the failure properties of human patellar tendons

    SciTech Connect

    Haut, R.C.; Powlison, A.C. )

    1990-07-01

    There is a need to document the mechanical properties of patellar tendon allografts used for reconstructive surgery of the damaged anterior cruciate ligament, especially the effects of irradiation sterilization. The purpose of this study was to investigate the influences of in vitro test environment and low-level cyclic stretching prior to failure tests on nonirradiated and irradiated human graft tissues. Bilateral patellar tendons were split and each half processed accordingly. Some graft tissues were stretched cyclically at 2.5 mm deformation before failure. Experiments were performed in a 37 degrees C saline bath or with tissues moistened with a drip of the same. The irradiated grafts relaxed less and generated less slack length in the drip environment than the nonirradiated controls. Cyclic stretching did not alter failure characteristics of either graft tissue. While no significant differences in the tensile responses or failure characteristics were noted for irradiated and nonirradiated grafts in the drip, in the bath environment the nonirradiated tissues had greater strength and modulus. This resulted in there being a significant difference between irradiated and nonirradiated tissue responses in a heated saline bath environment. These experimental results exemplify the need to control in vitro test environments in the evaluation of various sterilization and preservation protocols for soft tissue allografts.

  2. Transcription factor EGR1 directs tendon differentiation and promotes tendon repair

    PubMed Central

    Guerquin, Marie-Justine; Charvet, Benjamin; Nourissat, Geoffroy; Havis, Emmanuelle; Ronsin, Olivier; Bonnin, Marie-Ange; Ruggiu, Mathilde; Olivera-Martinez, Isabel; Robert, Nicolas; Lu, Yinhui; Kadler, Karl E.; Baumberger, Tristan; Doursounian, Levon; Berenbaum, Francis; Duprez, Delphine

    2013-01-01

    Tendon formation and repair rely on specific combinations of transcription factors, growth factors, and mechanical parameters that regulate the production and spatial organization of type I collagen. Here, we investigated the function of the zinc finger transcription factor EGR1 in tendon formation, healing, and repair using rodent animal models and mesenchymal stem cells (MSCs). Adult tendons of Egr1–/– mice displayed a deficiency in the expression of tendon genes, including Scx, Col1a1, and Col1a2, and were mechanically weaker compared with their WT littermates. EGR1 was recruited to the Col1a1 and Col2a1 promoters in postnatal mouse tendons in vivo. Egr1 was required for the normal gene response following tendon injury in a mouse model of Achilles tendon healing. Forced Egr1 expression programmed MSCs toward the tendon lineage and promoted the formation of in vitro–engineered tendons from MSCs. The application of EGR1-producing MSCs increased the formation of tendon-like tissues in a rat model of Achilles tendon injury. We provide evidence that the ability of EGR1 to promote tendon differentiation is partially mediated by TGF-β2. This study demonstrates EGR1 involvement in adult tendon formation, healing, and repair and identifies Egr1 as a putative target in tendon repair strategies. PMID:23863709

  3. Posterior Tibial Tendon Dysfunction (PTTD)

    MedlinePlus

    ... ACFAS | Información en Español Advanced Search Home » Foot & Ankle Conditions » Posterior Tibial Tendon Dysfunction (PTTD) Text Size ... the arch, and an inward rolling of the ankle. As the condition progresses, the symptoms will change. ...

  4. Light and electron microscopic study of stress-shielding effects on rat patellar tendon.

    PubMed

    Muellner, T; Kwasny, O; Loehnert, V; Mallinger, R; Unfried, G; Schabus, R; Plenk, H

    2001-11-01

    In this second part of our study, the histomorphologic changes occurring in the patellar tendon (PT) of rats after sole stress-shielding were evaluated. In seven adult albino rats, both PTs were exposed by straight skin incision and then stress-shielded on one side by a cerclage, while the contralateral PT served as the sham-operated control. One animal died after the operation and was used as a negative control. After 10 weeks of otherwise unrestricted motion, the rats were killed, and the histomorphology of all PT specimen pairs compared by light and transmission electron microscopy. Light microscopy showed mid-portion thickening and irregularity of collagen bundles in the stress-shielded tendons. Intense remodelling was demonstrated by increased cellularity and vascularity, as well as by enrichment in acidic proteoglycans. Ultrastructural evaluation and morphometry revealed a predominance of large diameter (peak between 180 and 260 nm) collagen fibrils in the sham-operated controls, while in the stress-shielded tendons the number of apparently new, small-diameter (peak between 40 and 60 nm) collagen fibrils increased (up to 77% per cross-sectional field of view). The difference in peak diameters was statistically significant (p < 0.0005). This rat model demonstrated that sole stress-shielding not only causes biomechanical alterations, but also intense tissue remodelling and significant morphological changes in the collagen fibrils in the patellar tendon, comparable to so-called 'ligamentization' in experimental and clinical patellar tendon grafts for anterior cruciate ligament reconstruction. PMID:11768636

  5. Surgical Treatment of Neglected Traumatic Quadriceps Tendon Rupture with Knee Ankylosis

    PubMed Central

    Lee, Seung-Hun; Seon, Jong-Keun; Woo, Seong-Hwan

    2016-01-01

    Quadriceps tendon rupture is an uncommon injury. This disabling condition is the result of direct or indirect trauma. It requires surgical repair to avoid poor outcomes in cases of neglected or chronic rupture. In most acute cases, simple tendon suture or reinsertion is suitable for an extensor mechanism reconstruction of the knee joint. However, chronic lesions often require a tendon graft or flap reconstruction. We report a case of a 15-year-old male who was diagnosed with a chronic quadriceps rupture with a patellar superior pole fracture. We performed quadriceps reconstruction using tibialis anterior allograft tendon and additional screw fixation to reconstruct the extensor mechanism and recover knee joint range of motion to prevent a high-level functional restriction. The treatment was difficult and limited due to neglect for 9-months that led to ankylosis accompanied with nonunion of tibial fracture. Our surgical treatment using allograft tendon resulted in a very good outcome after 30 months of follow-up. PMID:27274474

  6. Low-intensity pulsed ultrasound therapy: a potential strategy to stimulate tendon-bone junction healing.

    PubMed

    Ying, Zhi-min; Lin, Tiao; Yan, Shi-gui

    2012-12-01

    Incorporation of a tendon graft within the bone tunnel represents a challenging clinical problem. Successful anterior cruciate ligament (ACL) reconstruction requires solid healing of the tendon graft in the bone tunnel. Enhancement of graft healing to bone is important to facilitate early aggressive rehabilitation and a rapid return to pre-injury activity levels. No convenient, effective or inexpensive procedures exist to enhance tendon-bone (T-B) healing after surgery. Low-intensity pulsed ultrasound (LIPUS) improves local blood perfusion and angiogenesis, stimulates cartilage maturation, enhances differentiation and proliferation of osteoblasts, and motivates osteogenic differentiation of mesenchymal stem cells (MSCs), and therefore, appears to be a potential non-invasive tool for T-B healing in early stage of rehabilitation of ACL reconstruction. It is conceivable that LIPUS could be used to stimulate T-B tunnel healing in the home, with the aim of accelerating rehabilitation and an earlier return to normal activities in the near future. The purpose of this review is to demonstrate how LIPUS stimulates T-B healing at the cellular and molecular levels, describe studies in animal models, and provide a future direction for research. PMID:23225850

  7. Hyperuricemic PRP in tendon cells.

    PubMed

    Andia, I; Rubio-Azpeitia, E; Maffulli, N

    2014-01-01

    Platelet-rich plasma (PRP) is injected within tendons to stimulate healing. Metabolic alterations such as the metabolic syndrome, diabetes, or hyperuricemia could hinder the therapeutic effect of PRP. We hypothesise that tendon cells sense high levels of uric acid and this could modify their response to PRP. Tendon cells were treated with allogeneic PRPs for 96 hours. Hyperuricemic PRP did not hinder the proliferative actions of PRP. The gene expression pattern of inflammatory molecules in response to PRP showed absence of IL-1b and COX1 and modest expression of IL6, IL8, COX2, and TGF-b1. IL8 and IL6 proteins were secreted by tendon cells treated with PRP. The synthesis of IL6 and IL8 proteins induced by PRP is decreased significantly in the presence of hyperuricemia (P = 0.017 and P = 0.012, resp.). Concerning extracellular matrix, PRP-treated tendon cells displayed high type-1 collagen, moderate type-3 collagen, decorin, and hyaluronan synthase-2 expression and modest expression of scleraxis. Hyperuricemia modified the expression pattern of extracellular matrix proteins, upregulating COL1 (P = 0.036) and COMP (P = 0.012) and downregulating HAS2 (P = 0.012). Positive correlations between TGF-b1 and type-1 collagen (R = 0.905, P = 0.002) and aggrecan (R = 0.833, P = 0.010) and negative correlations between TGF-b1 and IL6 synthesis (R = -0.857, P = 0.007) and COX2 (R = -0.810, P = 0.015) were found. PMID:25276832

  8. Influence of Hamstring and Abdominal Muscle Activation on a Positive Ober's Test in People with Lumbopelvic Pain

    PubMed Central

    Tenney, H. Rich; DeBord, Aaron

    2013-01-01

    ABSTRACT Purpose: To assess the immediate effect of hamstring and abdominal activation on pain levels as measured by the Numeric Pain Scale (NPS) and hip range of motion as measured by Ober's Test in people with lumbopelvic pain. Methods: Thirteen participants with lumbopelvic pain and positive Ober's Tests completed an exercise developed by the Postural Restoration Institute™ to recruit hamstrings and abdominal muscles. Results: There was a significant increase in passive hip-adduction angles (p<0.01) and decrease in pain (p<0.01) immediately after the intervention. Conclusion: Specific exercises that activate hamstrings and abdominal muscles appear to immediately improve Ober's Test measurements and reduce pain as measured by the NPS in people with lumbo-pelvic pain. Hamstring/abdominal activation, rather than iliotibial band stretching, may be an effective intervention for addressing lumbopelvic pain and a positive Ober's Test. PMID:24381375

  9. Pectoralis Major Tendon Repair

    PubMed Central

    Cordasco, Frank A.; Degen, Ryan; Mahony, Gregory Thomas; Tsouris, Nicholas

    2016-01-01

    Objectives: Systematic reviews of the literature have identified 365 reported cases of Pectoralis Major Tendon (PMT) injuries. While surgical treatment has demonstrated improved outcomes compared to non-operative treatment, there is still relatively limited data on the functional outcome, return to sport and need for 2nd surgery in athletes following PMT repair. This study comprises the largest series of athletes following PMT repair reported to date. The Objective is to report on the functional outcomes, return to sport and need for 2nd surgery in a consecutive series of PMT tears. Methods: From 2009, 81 patients with PMT tears were enrolled in this prospective series. Baseline evaluation included patient demographics, mechanism of injury, physical examination and PMT specific MRI for confirmation of the diagnosis and analysis of the extent of injury. Each patient underwent surgical repair by the senior author utilizing a previously published surgical technique. Patients were then followed at 2 weeks, 6 weeks, 3 months and 6 months and further follow-up was conducted annually thereafter with functional outcome scores and adduction strength testing. The return to sport and incidence of 2nd surgery data were recorded. This study includes the first 40 athletes to reach the 2-year post-operative period. Results: All athletes were male, with an average age of 34.4 years (range 23-59). The patient cohort consisted of 4 professional NFL players and 36 recreational athletes. Average follow-up duration was 2.5 years (range 2 - 6.0 years). The most common mechanisms of injury occurred during the bench press (n=26) and contact sport participation (n=14). Sixteen injuries were complete avulsions involving both the clavicular and sternocostal heads, while 24 were isolated sternocostal head avulsions. Average pre-injury bench press of 396 lbs (range 170-500 lbs) was restored to 241 lbs post-operatively (range 140-550 lbs). Single Assessment Numeric Evaluation (SANE) scores

  10. Knee and Hip Joint Kinematics Predict Quadriceps and Hamstrings Neuromuscular Activation Patterns in Drop Jump Landings

    PubMed Central

    Malfait, Bart; Dingenen, Bart; Smeets, Annemie; Staes, Filip; Pataky, Todd; Robinson, Mark A.; Vanrenterghem, Jos; Verschueren, Sabine

    2016-01-01

    Purpose The purpose was to assess if variation in sagittal plane landing kinematics is associated with variation in neuromuscular activation patterns of the quadriceps-hamstrings muscle groups during drop vertical jumps (DVJ). Methods Fifty female athletes performed three DVJ. The relationship between peak knee and hip flexion angles and the amplitude of four EMG vectors was investigated with trajectory-level canonical correlation analyses over the entire time period of the landing phase. EMG vectors consisted of the {vastus medialis(VM),vastus lateralis(VL)}, {vastus medialis(VM),hamstring medialis(HM)}, {hamstring medialis(HM),hamstring lateralis(HL)} and the {vastus lateralis(VL),hamstring lateralis(HL)}. To estimate the contribution of each individual muscle, linear regressions were also conducted using one-dimensional statistical parametric mapping. Results The peak knee flexion angle was significantly positively associated with the amplitudes of the {VM,HM} and {HM,HL} during the preparatory and initial contact phase and with the {VL,HL} vector during the peak loading phase (p<0.05). Small peak knee flexion angles were significantly associated with higher HM amplitudes during the preparatory and initial contact phase (p<0.001). The amplitudes of the {VM,VL} and {VL,HL} were significantly positively associated with the peak hip flexion angle during the peak loading phase (p<0.05). Small peak hip flexion angles were significantly associated with higher VL amplitudes during the peak loading phase (p = 0.001). Higher external knee abduction and flexion moments were found in participants landing with less flexed knee and hip joints (p<0.001). Conclusion This study demonstrated clear associations between neuromuscular activation patterns and landing kinematics in the sagittal plane during specific parts of the landing. These findings have indicated that an erect landing pattern, characterized by less hip and knee flexion, was significantly associated with an

  11. Gender-based analysis of hamstring and quadriceps muscle activation during jump landings and cutting.

    PubMed

    Ebben, William P; Fauth, McKenzie L; Petushek, Erich J; Garceau, Luke R; Hsu, Brittni E; Lutsch, Brittney N; Feldmann, Christina R

    2010-02-01

    This study evaluated gender differences in the magnitude and timing of hamstring and quadriceps activation during activities that are believed to cause anterior cruciate ligament (ACL) injuries. Twelve men (age = 21.0 +/- 1.2 years; body mass = 81.61 +/- 13.3 kg; and jump height = 57.61 +/- 10.15 cm) and 12 women (age = 19.91 +/- 0.9 years; body mass = 64.36 +/- 6.14 kg; and jump height = 43.28 +/- 7.5) performed 3 repetitions each of the drop jump (jump) normalized to the subject's vertical jump height, and a sprint and cut at a 45-degree angle (cut). Electromyography (EMG) was used to quantify rectus femoris (RF), vastus lateralis (VL), vastus medialis (VM), lateral hamstring (LH), and medial hamstrings (MH) activation, timing, activation ratios, and timing ratios before and after foot contact for the jump and cut and normalized to each subject's hamstring and quadriceps maximum voluntary isometric contraction. Data were analyzed using an analysis of variance with results demonstrating that during the postcontact phase of the cut, men demonstrated greater LH and MH activation than women. In the precontact phase of the jump, men showed earlier activation of the VL and VM, than women. Women produced longer RF and VM muscle bursts during the postcontact phase of the cut. Additionally, men showed a trend toward higher hamstring to quadriceps activation ratio than women for the postcontact phase of the cut. This study provides evidence that men are LH dominant during the postcontact phase of the cut compared with women, whereas women sustain RF activation longer than men during this phase. Men activate quadriceps muscles earlier than women in the precontact phase of the jump. Training interventions may offer the potential for increasing the rate and magnitude of hamstring muscle activation. These outcomes should be evaluated using EMG during movements that are similar to those that cause ACL injuries to determine if gender differences in muscle activation can be

  12. Crossover Cutting During Hamstring Fatigue Produces Transverse Plane Knee Control Deficits

    PubMed Central

    Nyland, John A.; Caborn, David N.M.; Shapiro, Robert; Johnson, Darren L.

    1999-01-01

    Objective: To assess the effects of eccentric work-induced hamstring fatigue on sagittal and transverse plane (axial) knee and ankle biodynamics and kinetics during a running crossover cut directional change (functional pivot shift). Design and Setting: A pretest-posttest, single-group intervention experimental design was employed. All data were collected in a biodynamics laboratory. Subjects: Twenty healthy athletic females were trained for 3 weeks in crossover cutting before testing. Measurements: Data were sampled during 3 unfatigued and 3 fatigued (20% eccentric isokinetic knee-flexor torque reduction) crossover cut trials. Three-dimensional kinematic and ground reaction-force data were sampled at 200 Hz and 1000 Hz, respectively, and joint moment estimates were calculated. Data were standardized to initial force-plate heelstrike for comparisons of mean differences between conditions using paired t tests with Bonferroni adjustments. Pearson product-moment correlations compared kinematic and eccentric hamstring-torque relationships. Results: During internal rotation phase 1, between heelstrike and impact absorption, mean internal rotation velocity increased by 21.2°/s ± 114°/s. During internal rotation phase II, mean peak transverse plane knee rotation during propulsion decreased by 3.1° ± 9°. During internal rotation phase II, mean peak ankle plantar flexor moment onsets occurred 12.7 ± 53 milliseconds earlier, and this activation demonstrated a moderately positive relationship with the onset of mean peak knee internal rotation during propulsion and a weak negative relationship with mean peak hamstring torque/lean body weight. Conclusions: The increased knee internal rotation velocity during phase I indicates transverse plane dynamic knee-control deficits during hamstring fatigue. Earlier peak ankle plantar-flexor moments and decreased internal rotation during phase II in the presence of hamstring fatigue may represent compensatory attempts at dynamic

  13. Effect of ACL Graft Type on Side-Step Cutting in Young Athletes

    PubMed Central

    Pace, James Lee; Mueske, Nicole; Padilla, Ricardo A.; Katzel, Mia; Healy, Bitte S.; Wren, Tishya

    2016-01-01

    Objectives: Due to the slightly higher re-tear rate for ACL reconstruction (ACLR) with hamstring (HT) versus patellar tendon (PT), differences in movement strategies were assessed during side-step cutting in young athletes with recent ACLR to determine if graft type affected post-operative motion. Methods: Dominant limbs from 21 athletes without lower extremity injury or previous surgery (age 14.9 ± 2.0 years) and 26 limbs with recent (5.1-8.0 months post-operative) unilateral ACLR were included, 18 with HT grafts (age 16.6 ± 3.7 years) and 8 with PT (age 16.7 ± 1.2 years). Lower extremity 3-dimensional data was recorded during the deceleration phase (initial contact to maximum knee flexion) of a 45° cut. Group differences were assessed using analysis of variance with Bonferroni post-hoc tests. Results: The HT group had a slower approach velocity than controls (2.9 vs. 3.5 m/s; p=0.006) with intermediate velocity in the PT group (3.2 m/s). Both the HT and PT groups had lower peak ground reaction force (GRF) compared to controls (HT: 2.0 body weights, PT: 2.2 BW, Control: 2.8 BW; p≤0.02), along with lower peak knee flexion moments (HT: 1.4 Nm/kg, PT: 1.3 Nm/kg, Control: 2.2 Nm/kg; p=0.002). The PT group had less power absorption at the knee than controls (0.3 vs. 0.7 Nm/kg; p=0.07), while the HT group had more at the hip (0.4 vs. 0.1 Nm/kg; p=0.04). The HT group also had higher peak hip flexion (HT: 65.8°, PT: 53.9°, Control: 55.1°; p≤0.06) and hip sagittal plane excursion (HT: 9.4°, PT: 3.6°, Control: 2.8°; p≤0.05) than the PT and control groups. The HT group had lower peak knee valgus moments than controls (0.05 vs. 1.2 Nm/kg; p=0.01) as well as a greater range of frontal plane pelvic (8.2° vs. 3.4°; p=0.03) and hip (7.6° vs. 3.0°; p=0.05) motion. The PT group had intermediate values for valgus moment (0.8 Nm/kg) and pelvic (4.9°) and hip (3.3°) excursion. Conclusion: While both ACLR groups showed reduced GRFs and knee flexion moments

  14. Mechanisms of tendon injury and repair

    PubMed Central

    Thomopoulos, Stavros; Parks, William C.; Rifkin, Daniel B.; Derwin, Kathleen A.

    2015-01-01

    Tendon disorders are common and lead to significant disability, pain, healthcare cost, and lost productivity. A wide range of injury mechanisms exist leading to tendinopathy or tendon rupture. Tears can occur in healthy tendons that are acutely overloaded (e.g., during a high speed or high impact event) or lacerated (e.g., a knife injury). Tendinitis or tendinosis can occur in tendons exposed to overuse conditions (e.g., an elite swimmer’s training regimen) or intrinsic tissue degeneration (e.g., age-related degeneration). The healing potential of a torn or pathologic tendon varies depending on anatomic location (e.g., Achilles vs. rotator cuff) and local environment (e.g., intrasynovial vs. extrasynovial). Although healing occurs to varying degrees, in general healing of repaired tendons follows the typical wound healing course, including an early inflammatory phase, followed by proliferative and remodeling phases. Numerous treatment approaches have been attempted to improve tendon healing, including growth factor- and cell-based therapies and rehabilitation protocols. This review will describe the current state of knowledge of injury and repair of the three most common tendinopathies-- flexor tendon lacerations, Achilles tendon rupture, and rotator cuff disorders-- with a particular focus on the use of animal models for understanding tendon healing. PMID:25641114

  15. Enhancement of tendon-bone healing via the combination of biodegradable collagen-loaded nanofibrous membranes and a three-dimensional printed bone-anchoring bolt.

    PubMed

    Chou, Ying-Chao; Yeh, Wen-Lin; Chao, Chien-Lin; Hsu, Yung-Heng; Yu, Yi-Hsun; Chen, Jan-Kan; Liu, Shih-Jung

    2016-01-01

    A composite biodegradable polymeric model was developed to enhance tendon graft healing. This model included a biodegradable polylactide (PLA) bolt as the bone anchor and a poly(D,L-lactide-co-glycolide) (PLGA) nanofibrous membrane embedded with collagen as a biomimic patch to promote tendon-bone interface integration. Degradation rate and compressive strength of the PLA bolt were measured after immersion in a buffer solution for 3 months. In vitro biochemical characteristics and the nanofibrous matrix were assessed using a water contact angle analyzer, pH meter, and tetrazolium reduction assay. In vivo efficacies of PLGA/collagen nanofibers and PLA bolts for tendon-bone healing were investigated on a rabbit bone tunnel model with histological and tendon pullout tests. The PLGA/collagen-blended nanofibrous membrane was a hydrophilic, stable, and biocompatible scaffold. The PLA bolt was durable for tendon-bone anchoring. Histology showed adequate biocompatibility of the PLA bolt on a medial cortex with progressive bone ingrowth and without tissue overreaction. PLGA nanofibers within the bone tunnel also decreased the tunnel enlargement phenomenon and enhanced tendon-bone integration. Composite polymers of the PLA bolt and PLGA/collagen nanofibrous membrane can effectively promote outcomes of tendon reconstruction in a rabbit model. The composite biodegradable polymeric system may be useful in humans for tendon reconstruction. PMID:27601901

  16. The Effects of Glucocorticoid on Tendon and Tendon Derived Cells.

    PubMed

    Dean, Benjamin John Floyd; Carr, Andrew Jonathan

    2016-01-01

    Glucocorticoids are generally used to relieve pain and/or inflammation in a wide variety of musculoskeletal disorders including osteoarthritis, inflammatory arthritis, tendinopathy and degenerative spine disease. Glucocorticoids reduce tendon derived cell proliferation in vitro and reduce extracellular matrix synthesis both in vitro and in vivo, in particular type I collagen synthesis. Glucocorticoids also appear to result in acute deleterious changes in healthy in vivo tendon including collagen necrosis, collagen disorganisation and inflammatory cell infiltration; while the overall effect of glucocorticoid administration on the mechanical properties of healthy in vivo tendon are generally negative. Overall the existing in vitro and in vivo evidence suggests that glucocorticoids should be used with caution in treating painful tendinopathy. Certainly a real need exists to follow up the long term clinical effects of glucocorticoid in treating tendinopathy, as there is currently a paucity of evidence in this area. However in this context while the short term benefits are clear, glucocorticoids remain a useful treatment option provided they are used in the right patients in sensible moderation. PMID:27535266

  17. Active Achilles tendon kinesitherapy accelerates Achilles tendon repair by promoting neurite regeneration☆

    PubMed Central

    Jielile, Jiasharete; Aibai, Minawa; Sabirhazi, Gulnur; Shawutali, Nuerai; Tangkejie, Wulanbai; Badelhan, Aynaz; Nuerduola, Yeermike; Satewalede, Turde; Buranbai, Darehan; Hunapia, Beicen; Jialihasi, Ayidaer; Bai, Jingping; Kizaibek, Murat

    2012-01-01

    Active Achilles tendon kinesitherapy facilitates the functional recovery of a ruptured Achilles tendon. However, protein expression during the healing process remains a controversial issue. New Zealand rabbits, aged 14 weeks, underwent tenotomy followed immediately by Achilles tendon microsurgery to repair the Achilles tendon rupture. The tendon was then immobilized or subjected to postoperative early motion treatment (kinesitherapy). Mass spectrography results showed that after 14 days of motion treatment, 18 protein spots were differentially expressed, among which, 12 were up-regulated, consisting of gelsolin isoform b and neurite growth-related protein collapsing response mediator protein 2. Western blot analysis showed that gelsolin isoform b was up-regulated at days 7–21 of motion treatment. These findings suggest that active Achilles tendon kinesitherapy promotes the neurite regeneration of a ruptured Achilles tendon and gelsolin isoform b can be used as a biomarker for Achilles tendon healing after kinesitherapy. PMID:25317130

  18. Active Achilles tendon kinesitherapy accelerates Achilles tendon repair by promoting neurite regeneration.

    PubMed

    Jielile, Jiasharete; Aibai, Minawa; Sabirhazi, Gulnur; Shawutali, Nuerai; Tangkejie, Wulanbai; Badelhan, Aynaz; Nuerduola, Yeermike; Satewalede, Turde; Buranbai, Darehan; Hunapia, Beicen; Jialihasi, Ayidaer; Bai, Jingping; Kizaibek, Murat

    2012-12-15

    Active Achilles tendon kinesitherapy facilitates the functional recovery of a ruptured Achilles tendon. However, protein expression during the healing process remains a controversial issue. New Zealand rabbits, aged 14 weeks, underwent tenotomy followed immediately by Achilles tendon microsurgery to repair the Achilles tendon rupture. The tendon was then immobilized or subjected to postoperative early motion treatment (kinesitherapy). Mass spectrography results showed that after 14 days of motion treatment, 18 protein spots were differentially expressed, among which, 12 were up-regulated, consisting of gelsolin isoform b and neurite growth-related protein collapsing response mediator protein 2. Western blot analysis showed that gelsolin isoform b was up-regulated at days 7-21 of motion treatment. These findings suggest that active Achilles tendon kinesitherapy promotes the neurite regeneration of a ruptured Achilles tendon and gelsolin isoform b can be used as a biomarker for Achilles tendon healing after kinesitherapy. PMID:25317130

  19. Tensile mechanical properties of human forearm tendons.

    PubMed

    Weber, J F; Agur, A M R; Fattah, A Y; Gordon, K D; Oliver, M L

    2015-09-01

    Previous studies of the mechanical properties of tendons in the upper limb have used embalmed specimens or sub-optimal methods of measurement. The aim of this study was to determine the biomechanical properties of all tendons from five fresh frozen cadaveric forearms using updated methodology. The cross-sectional area of tendons was accurately measured using a laser reflectance system. Tensile testing was done in a precision servo-hydraulic device with cryo-clamp fixation. We determined that the cross-sectional area of some tendons is variable and directly influences the calculated material properties; visual estimation of this is unreliable. Data trends illustrate that digital extensor tendons possess the greatest tensile strength and a higher Young's modulus than other tendon types. PMID:25940499

  20. On the mechanical function of tendon.

    PubMed

    Kafka, V; Jírová, J; Smetana, V

    1995-01-01

    A mesoscopic approach is followed for mathematical modelling of the specific deformation properties of tendon. The approach starts from our general concept of modelling mechanical behaviour of heterogeneous media and assumes that the structure of tendon is optimized in such a way that it enables its adjacent muscle to work with a constant performance in the course of increasing loading (acting like a gearbox in a car). The model based on this assumption gives results that are in a very good accordance with observed properties of tendons. Clinical experience reveals that if this function of tendon is violated pathological changes appear in the respective muscle. RELEVANCE: Clarification and mathematical modelling of the mechanical function of tendon is of intellectual interest in its own right, but it is important also for cautioning surgeons against unnecessary violation of this function, and for tissue engineering aspects if tendon must be replaced. PMID:11415531

  1. Dynamic behavior of tendons in random seas

    SciTech Connect

    Niedzwecki, J.M.; Rijken, O.R.; Soemantri, D.S.

    1995-12-31

    The dynamic behavior of large scale (1:55) undistorted models of TLP tendons were investigated. The tendons modeled were for a TLP designed to be deployed in a water depth of 914 m. The tendon motions were studied without the presence of the hull, In the study reported, the tendon models were subjected to three quite different design seas and the single and paired tendon configurations were compared under identical wave conditions. The main objective of this study was to examine the dynamic response of TLP tendons under controlled environmental conditions in order to better quantify the observed dynamic behavior. Underwater video tracking techniques were utilized in the experiments to obtain direct measurement of the inline and transverse displacements. Envelopes characterizing the extreme displacement behavior, spatial variations in response and collision behavior are presented and discussed.

  2. Nutrient pathways of flexor tendons in primates

    SciTech Connect

    Manske, P.R.; Lesker, P.A.

    1982-09-01

    The perfusion and diffusion pathways to the flexor profundus tendons of 40 monkeys were investigated by measuring the uptake of tritiated proline by various tendon segments. In the absence of all vascular connections, the process of diffusion provides nutrients to all areas of flexor tendon and in this study the process of diffusion was greater. The distal segment of tendon was observed to be profused most rapidly. The proximal tendon segment is perfused from both the muscular-tendinous junction and the vinculum longus; vincular segment perfusion is via the vinculum longus vessels alone; central segment perfusion is shared by the vinculum longus and vinculum brevis vasculature. The distal segment uptake is by both the process of diffusion or vinculum brevis perfusion. The osseous attachment at the distal phalanx contributes little to tendon nutrition.

  3. Static Stretching of the Hamstring Muscle for Injury Prevention in Football Codes: a Systematic Review

    PubMed Central

    Rogan, Slavko; Wüst, Dirk; Schwitter, Thomas; Schmidtbleicher, Dietmar

    2012-01-01

    Purpose Hamstring injuries are common among football players. There is still disagreement regarding prevention. The aim of this review is to determine whether static stretching reduces hamstring injuries in football codes. Methods A systematic literature search was conducted on the online databases PubMed, PEDro, Cochrane, Web of Science, Bisp and Clinical Trial register. Study results were presented descriptively and the quality of the studies assessed were based on Cochrane's ‘risk of bias’ tool. Results The review identified 35 studies, including four analysis studies. These studies show deficiencies in the quality of study designs. Conclusion The study protocols are varied in terms of the length of intervention and follow-up. No RCT studies are available, however, RCT studies should be conducted in the near future. PMID:23785569

  4. Platelet-rich plasma treatment improves outcomes for chronic proximal hamstring injuries in an athletic population

    PubMed Central

    Fader, Ryan R.; Mitchell, Justin J.; Traub, Shaun; Nichols, Roger; Roper, Michelle; Mei Dan, Omer; McCarty, Eric C.

    2014-01-01

    Summary Background: chronic proximal hamstring tendinopathies is a disabling activity related condition. Currently, there is no well-accepted or extensively documented non-operative treatment option that provides consistently successful results. Purpose: to evaluate the efficacy of ultrasound guided platelet-rich plasma injections in treating chronic proximal hamstring tendinopathies. Methods: a total of 18 consecutive patients were retrospectively analyzed. All patients received a single injection of platelet rich plasma via ultra-sound guidance by a single radiologist. Outcome measures included a questionnaire evaluating previous treatments, visual analog scale (VAS) for pain, subjective improvement, history of injury, and return to activity. Results: the patient population included 12 females and 6 males. The average age at the time of the injection was 42.6 years (19–60). Provocative activities included running, biking, swimming. The average body mass index of patients was 22.9 (17.2–30.2). The average time of chronic pain prior to receiving the first injection was 32.6 months (6–120). All patients had attempted other forms of non-surgical treatment prior to entering the study. The average VAS pre-injection was 4.6 (0–8). Six months after the injection, 10/18 patients had 80% or greater improvement in their VAS. Overall, the average improvement was 63% (5–100). The only documented side effect was post-injection discomfort that resolved within seventy-two hours. Conclusion: chronic hamstring tendinopathy is a debilitating condition secondary to the pain, which limits an athlete’s ability to perform. For refractory cases of chronic insertional proximal hamstring injuries, platelet-rich plasma injections are safe and show benefit in the majority of patients in our study, allowing return to pre-injury activities. Study Design: Case series; Level of evidence, 4. PMID:25767784

  5. Biceps femoris and semitendinosus—teammates or competitors? New insights into hamstring injury mechanisms in male football players: a muscle functional MRI study

    PubMed Central

    Schuermans, Joke; Van Tiggelen, Damien; Danneels, Lieven; Witvrouw, Erik

    2014-01-01

    Background The hamstring injury mechanism was assessed by investigating the exercise-related metabolic activity characteristics of the hamstring muscles using a muscle functional MRI (mfMRI) protocol. Methods 27 healthy male football players and 27 football players with a history of hamstring injuries (recovered and playing fully) underwent standardised mfMR Imaging. The mfMRI protocol consisted of a resting scan, a strenuous bilateral eccentric hamstring exercise and a postexercise scan. The exercise-related T2 increase or the signal intensity shift between both scans was used to detect differences in metabolic activation characteristics (1) between the different hamstring muscle bellies and (2) between the injury group and the control group. Results A more symmetrical muscle recruitment pattern corresponding to a less economic hamstring muscle activation was demonstrated in the formerly injured group (p<0.05). The injured group also demonstrated a significantly lower strength endurance capacity during the eccentric hamstring exercise. Conclusions These findings suggest that the vulnerability of the hamstring muscles to football-related injury is related to the complexity and close coherence in the synergistic muscle recruitment of the biceps femoris and the semitendinosus. Discrete differences in neuromuscular coordination and activity distribution, with the biceps femoris partly having to compensate for the lack of endurance capacity of the semitendinosus, probably increase the hamstring injury risk. PMID:25388959

  6. Crucial transcription factors in tendon development and differentiation: their potential for tendon regeneration.

    PubMed

    Liu, Huanhuan; Zhu, Shouan; Zhang, Can; Lu, Ping; Hu, Jiajie; Yin, Zi; Ma, Yue; Chen, Xiao; OuYang, Hongwei

    2014-05-01

    Tendons that connect muscles to bone are often the targets of sports injuries. The currently unsatisfactory state of tendon repair is largely attributable to the limited understanding of basic tendon biology. A number of tendon lineage-related transcription factors have recently been uncovered and provide clues for the better understanding of tendon development. Scleraxis and Mohawk have been identified as critical transcription factors in tendon development and differentiation. Other transcription factors, such as Sox9 and Egr1/2, have also been recently reported to be involved in tendon development. However, the molecular mechanisms and application of these transcription factors remain largely unclear and this prohibits their use in tendon therapy. Here, we systematically review and analyze recent findings and our own data concerning tendon transcription factors and tendon regeneration. Based on these findings, we provide interaction and temporal programming maps of transcription factors, as a basis for future tendon therapy. Finally, we discuss future directions for tendon regeneration with differentiation and trans-differentiation approaches based on transcription factors. PMID:24705622

  7. Effects of forward trunk lean on hamstring muscle kinematics during sprinting.

    PubMed

    Higashihara, Ayako; Nagano, Yasuharu; Takahashi, Kazumasa; Fukubayashi, Toru

    2015-01-01

    This study aimed to investigate the effects of forward trunk lean on hamstring muscle kinematics during sprinting. Eight male sprinters performed maximal-effort sprints in two trunk positions: forward lean and upright. A three-dimensional musculoskeletal model was used to compute the musculotendon lengths and velocity of the biceps femoris long head, semitendinosus, and semimembranosus muscles during the sprinting gait cycle. The musculotendon lengths of all the three hamstring muscles at foot strike and toe-off were significantly greater during the forward trunk lean sprint than during the upright trunk sprint. In addition, a positive peak musculotendon lengthening velocity was observed in the biceps femoris long head and semimembranosus muscles during the late stance phase, and musculotendon lengths at that instant were significantly greater during the forward trunk lean sprint than during the upright trunk sprint. The present study provides significant evidence that a potential for hamstring muscle strain injury involving forward trunk lean sprinting would exist during the stance phase. The results also indicate that the biceps femoris long head and semimembranosus muscles are stretched during forward trunk lean sprinting while contracting eccentrically in the late stance phase; thus, the elongation load on these muscles could be increased. PMID:25514378

  8. Isolated hamstrings fatigue alters hip and knee joint coordination during a cutting maneuver.

    PubMed

    Samaan, Michael A; Hoch, Matthew C; Ringleb, Stacie I; Bawab, Sebastian; Weinhandl, Joshua T

    2015-04-01

    The aim of this study was to determine the effects of hamstrings fatigue on lower extremity joint coordination variability during a sidestep cutting maneuver. Twenty female recreational athletes performed five successful trials of a sidestep cutting task pre- and postfatigue. Each participant completed an isolated hamstrings fatigue protocol consisting of isokinetic maximum effort knee flexion and passive extension contractions. Vector coding was used to examine hip and knee joint couplings (consisting of various planar motions) during the impact and weight acceptance phases of the sidestep cut stance phase. Paired t tests were used to analyze differences of each phase as an effect of fatigue, where alpha was set a priori at .05. The hip rotation/knee rotation coupling exhibited a significant decrease in coordination variability as a function of fatigue in both the impact (P = .015) and weight acceptance phases (P = .043). Similarly, the hip adduction-abduction/knee rotation coupling exhibited a significant decrease in coordination variability in the weight acceptance phase (P = .038). Hamstrings fatigue significantly decreased coordination variability within specific lower extremity joint couplings that included knee rotation. Future studies should be conducted to determine if this decrease in coordination variability is related to lower extremity injury mechanisms. PMID:25411821

  9. Platelet-rich plasma in the treatment of acute hamstring injuries in professional football players

    PubMed Central

    ZANON, GIACOMO; COMBI, FRANCO; COMBI, ALBERTO; PERTICARINI, LORIS; SAMMARCHI, LUIGI; BENAZZO, FRANCESCO

    2016-01-01

    Purpose muscle injuries have a high incidence in professional football and are responsible for the largest number of days lost from competition. Several in vitro studies have confirmed the positive role of platelet-rich plasma (PRP) in accelerating recovery and in promoting muscle regeneration, and not fibrosis, in the healing process. This study examines the results of intralesional administration of PRP in the treatment of primary hamstring injuries sustained by players belonging to a major league football club. Methods twenty-five hamstring injuries (grade 2 according to MRI classification) sustained by professional football players during a 31-months observation period were treated with PRP and analyzed. Sport participation absence (SPA), in days, was considered to correspond to the healing time, and we also considered the re-injury rate, and tissue healing on MRI. The mean follow-up was 36.6 months (range 22–42). Results there were no adverse events. The mean SPA for the treated muscle injuries was 36.76±19.02 days. The re-injury rate was 12%. Tissue healing, evaluated on MRI, was characterized by the presence of excellent repair tissue and a small scar. Conclusions this study confirmed the safety of PRP in treating hamstring lesions in a large series of professional football players. PRP-treated lesions did not heal more quickly than untreated lesions described in the literature, but they showed a smaller scar and excellent repair tissue. Level of evidence Level IV, therapeutic case series. PMID:27386443

  10. Relationship between the peak time of hamstring stretch and activation during sprinting.

    PubMed

    Higashihara, Ayako; Nagano, Yasuharu; Ono, Takashi; Fukubayashi, Toru

    2016-01-01

    The purpose of this study was to investigate the time series relationships between the peak musculotendon length and electromyography (EMG) activation during overground sprinting to clarify the risk of muscle strain injury incidence in each hamstring muscle. Full-body kinematics and EMG of the right biceps femoris long head (BFlh) and semitendinosus (ST) muscles were recorded in 13 male sprinters during overground sprinting at maximum effort. The hamstring musculotendon lengths during sprinting were computed using a three-dimensional musculoskeletal model. The time of the peak musculotendon length, in terms of the percentage of the running gait cycle, was measured and compared with that of the peak EMG activity. The maximum length of the hamstring muscles was noted during the late swing phase of sprinting. The peak musculotendon length was synchronous with the peak EMG activation in the BFlh muscle, while the time of peak musculotendon length in the ST muscle occurred significantly later than the peak level of EMG activation (p < 0.05). These results suggest that the BFlh muscle is exposed to an instantaneous high tensile force during the late swing phase of sprinting, indicating a higher risk for muscle strain injury. PMID:25360992

  11. High axial load termination for TLP tendons

    SciTech Connect

    Salama, M.M.

    1992-03-03

    This patent describes a hollow high axial load termination for a composite tubular tendon. It comprises: a curved hollow termination body open at one end wit a circular opening and connected at the opposite curved end with an elongated hollow member of lesser diameter than the diameter of the circular opening of the termination body, a composite tubular tendon containing axial fibers and helical fibers laid on an inner hollow liner; fibers of the composite tubular tendon extending over and covering the termination body from the abutment with the composite tubular tendon to the elongated member of lesser diameter than the termination body.

  12. Tendon Transfers in the Rheumatoid Hand for Reconstruction.

    PubMed

    O'Sullivan, Michael Brody; Singh, Hardeep; Wolf, Jennifer Moriatis

    2016-08-01

    Long-standing rheumatoid arthritis can result in spontaneous tendon rupture caused by attrition of the tendons. Ruptures of the ulnar-sided extensor tendons, flexor pollicis longus, and the flexor digitorum profundus can be seen. Primary repair of these tendon ruptures is frequently not possible because of delayed presentation and tendon damage by the disease process. Tendon transfers are the preferred method of treatment in patients with rheumatoid arthritis. At surgery, it is critical to address the underlying cause of rupture to prevent future tendon ruptures. Rates of tendon rupture may decrease due to improved medications for rheumatoid arthritis. PMID:27387084

  13. At return to play following hamstring injury the majority of professional football players have residual isokinetic deficits

    PubMed Central

    Tol, Johannes L; Hamilton, Bruce; Eirale, Cristiano; Muxart, Patrice; Jacobsen, Philipp; Whiteley, Rod

    2014-01-01

    Background There is an ongoing debate regarding the optimal criteria for return to sport after an acute hamstring injury. Less than 10% isokinetic strength deficit is generally recommended but this has never been documented in professional football players after rehabilitation. Our aim was to evaluate isokinetic measurements in MRI-positive hamstring injuries. Methods Isokinetic measurements of professional football players were obtained after completing a standardised rehabilitation programme. An isokinetic strength deficit of more than 10% compared with the contralateral site was considered abnormal. Reinjuries within 2 months were recorded. Results 52 players had a complete set of isokinetic testing before clinical discharge. There were 27 (52%) grade 1 and 25 (48%) grade 2 injuries. 35 of 52 players (67%) had at least one of the three hamstring-related isokinetic parameters that display a deficit of more than 10%. The percentage of players with 10% deficit for hamstring concentric 60°/s, 300°/s and hamstring eccentric was respectively 39%, 29% and 28%. There was no significant difference of mean isokinetic peak torques and 10% isokinetic deficits in players without reinjury (N=46) compared with players with reinjury (N=6). Conclusions When compared with the uninjured leg, 67% of the clinically recovered hamstring injuries showed at least one hamstring isokinetic testing deficit of more than 10%. Normalisation of isokinetic strength seems not to be a necessary result of the successful completion of a football-specific rehabilitation programme. The possible association between isokinetic strength deficit and increased reinjury risk remains unknown. PMID:24493666

  14. Patterns of Hamstring Muscle Tears in the General Population: A Systematic Review

    PubMed Central

    Kuske, Barbara; Hamilton, David F.; Pattle, Sam B.; Simpson, A. Hamish R. W.

    2016-01-01

    Background Hamstring tears are well recognised in the sporting population. Little is known about these injuries in the general population. Purpose Evaluating the rates, patterns and risk factors of non-sporting hamstring tears, compared to sporting related hamstring tears. Data Sources MEDLINE, EMBASE, CINAHL, and the Cochrane Central Register of Controlled Trials (1989–2015). Study Selection Studies reporting patients with a grade 2 or 3 hamstring muscle tear, identified clinically, confirmed by MRI imaging or direct visualisation during surgical exploration. Data Synthesis 144 sets of linked data were extracted for analysis. Most injuries were in males (81.3%), where mean age at injury was lower (30.2, 95% CI 29.1–31.3) than in females (35.4, 95% CI 32.4–38.4) p = 0.06. Key differences were found in the proportion of non-sporting injuries in patients under and over the age 40 (p = 0.001). The proportion of non-sporting injuries was significantly higher in females compared to males (25.9% female non-sporting injuries, versus 8.5% male; p = 0.02). Avulsions were more frequently reported in non-sporting activities (70.5%). The proportion of such injuries was notably higher in females, though this failed to meet significance (p = 0.124). Grouped by age category a bimodal distribution was noted, with the proportion of avulsions greater in younger (age <15) and older patients (age > 40) (p = 0.008). 86.8% of patients returned to pre-injury activity levels with a similar frequency across all study variables; age, activity (sporting vs non-sporting) and injury type (avulsion vs tear). Conclusion This review highlights a proportion of adults suffering grade 2 or 3 hamstring injuries from activities other than the classic sports trauma. The majority of these non-sporting injuries were avulsion injuries that clustered in older female and skeletally immature patients suggesting a potential link to bone mineral density. PMID:27144648

  15. Hamstrings to quadriceps peak torque ratios diverge between sexes with increasing isokinetic angular velocity.

    PubMed

    Hewett, Timothy E; Myer, Gregory D; Zazulak, Bohdanna T

    2008-09-01

    Our purpose was to determine if females demonstrate decreased hamstrings to quadriceps peak torque (H/Q) ratios compared to males and if H/Q ratios increase with increased isokinetic velocity in both sexes. Maturation disproportionately increases hamstrings peak torque at high velocity in males, but not females. Therefore, we hypothesised that mature females would demonstrate decreased H/Q ratios compared to males and the difference in H/Q ratio between sexes would increase as isokinetic velocity increased. Studies that analysed the H/Q ratio with gravity corrected isokinetic strength testing reported between 1967 and 2004 were included in our review and analysis. Keywords were hamstrings/quadriceps, isokinetics, peak torque and gravity corrected. Medline and Smart databases were searched combined with cross-checked bibliographic reference lists of the publications to determine studies to be included. Twenty-two studies were included with a total of 1568 subjects (1145 male, 423 female). Males demonstrated a significant correlation between H/Q ratio and isokinetic velocity (R=0.634, p<0.0001), and a significant difference in the isokinetic H/Q ratio at the lowest angular velocity (47.8+/-2.2% at 30 degrees /s) compared to the highest velocity (81.4+/-1.1% at 360 degrees /s, p<0.001). In contrast, females did not demonstrate a significant relationship between H/Q ratio and isokinetic velocity (R=0.065, p=0.77) or a change in relative hamstrings strength as the speed increased (49.5+/-8.8% at 30 degrees /s; 51.0+/-5.7% at 360 degrees /s, p=0.84). Gender differences in isokinetic H/Q ratios were not observed at slower angular velocities. However, at high knee flexion/extension angular velocities, approaching those that occur during sports activities, significant gender differences were observed in the H/Q ratio. Females, unlike males, do not increase hamstrings to quadriceps torque ratios at velocities that approach those of functional activities. PMID:17875402

  16. Hamstrings to quadriceps peak torque ratios diverge between sexes with increasing isokinetic angular velocity

    PubMed Central

    Hewett, Timothy E.; Myer, Gregory D.; Zazulak, Bohdanna T.

    2012-01-01

    Summary Our purpose was to determine if females demonstrate decreased hamstrings to quadriceps peak torque (H/Q) ratios compared to males and if H/Q ratios increase with increased isokinetic velocity in both sexes. Maturation disproportionately increases hamstrings peak torque at high velocity in males, but not females. Therefore, we hypothesised that mature females would demonstrate decreased H/Q ratios compared to males and the difference in H/Q ratio between sexes would increase as isokinetic velocity increased. Studies that analysed the H/Q ratio with gravity corrected isokinetic strength testing reported between 1967 and 2004 were included in our review and analysis. Keywords were hamstrings/quadriceps, isokinetics, peak torque and gravity corrected. Medline and Smart databases were searched combined with cross-checked bibliographic reference lists of the publications to determine studies to be included. Twenty-two studies were included with a total of 1568 subjects (1145 male, 423 female). Males demonstrated a significant correlation between H/Q ratio and isokinetic velocity (R = 0.634, p < 0.0001), and a significant difference in the isokinetic H/Q ratio at the lowest angular velocity (47.8 ± 2.2% at 30°/s) compared to the highest velocity (81.4 ± 1.1% at 360°/s, p < 0.001). In contrast, females did not demonstrate a significant relationship between H/Q ratio and isokinetic velocity (R = 0.065, p = 0.77) or a change in relative hamstrings strength as the speed increased (49.5 ± 8.8% at 30°/s; 51.0 ± 5.7% at 360°/s, p = 0.84). Gender differences in isokinetic H/Q ratios were not observed at slower angular velocities. However, at high knee flexion/extension angular velocities, approaching those that occur during sports activities, significant gender differences were observed in the H/Q ratio. Females, unlike males, do not increase hamstrings to quadriceps torque ratios at velocities that approach those of functional activities. PMID:17875402

  17. Distribution of proteins within different compartments of tendon varies according to tendon type.

    PubMed

    Thorpe, Chavaunne T; Karunaseelan, Kabelan J; Ng Chieng Hin, Jade; Riley, Graham P; Birch, Helen L; Clegg, Peter D; Screen, Hazel R C

    2016-09-01

    Although the predominant function of all tendons is to transfer force from muscle to bone and position the limbs, some tendons additionally function as energy stores, reducing the energetic cost of locomotion. To maximise energy storage and return, energy-storing tendons need to be more extensible and elastic than tendons with a purely positional function. These properties are conferred in part by a specialisation of a specific compartment of the tendon, the interfascicular matrix, which enables sliding and recoil between adjacent fascicles. However, the composition of the interfascicular matrix is poorly characterised and we therefore tested the hypothesis that the distribution of elastin and proteoglycans differs between energy-storing and positional tendons, and that protein distribution varies between the fascicular matrix and the interfascicular matrix, with localisation of elastin and lubricin to the interfascicular matrix. Protein distribution in the energy-storing equine superficial digital flexor tendon and positional common digital extensor tendon was assessed using histology and immunohistochemistry. The results support the hypothesis, demonstrating enrichment of lubricin in the interfascicular matrix in both tendon types, where it is likely to facilitate interfascicular sliding. Elastin was also localised to the interfascicular matrix, specifically in the energy-storing superficial digital flexor tendon, which may account for the greater elasticity of the interfascicular matrix in this tendon. A differential distribution of proteoglycans was identified between tendon types and regions, which may indicate a distinct role for each of these proteins in tendon. These data provide important advances into fully characterising structure-function relationships within tendon. PMID:27113131

  18. Simultaneous and spontaneous bilateral quadriceps tendons rupture.

    PubMed

    Celik, Evrim Coşkun; Ozbaydar, Mehmet; Ofluoglu, Demet; Demircay, Emre

    2012-07-01

    Simultaneous and spontaneous bilateral quadriceps tendon rupture is an uncommon injury that is usually seen in association with multiple medical conditions and some medications. We report a case of simultaneous and spontaneous bilateral quadriceps tendon rupture that may be related to the long-term use of a statin. PMID:22561379

  19. Measuring Regional Changes in Damaged Tendon

    NASA Astrophysics Data System (ADS)

    Frisch, Catherine Kayt Vincent

    Mechanical properties of tendon predict tendon health and function, but measuring these properties in vivo is difficult. An ultrasound-based (US) analysis technique called acoustoelastography (AE) uses load-dependent changes in the reflected US signal to estimate tissue stiffness non-invasively. This thesis explores whether AE can provide information about stiffness alteration resulting from tendon tears both ex vivo and in vivo. An ex vivo ovine infraspinatus tendon model suggests that the relative load transmitted by the different tendon layers transmit different fractions of the load and that ultrasound echo intensity change during cyclic loading decreases, becoming less consistent once the tendon is torn. An in vivo human tibialis anterior tendon model using electrically stimulated twitch contractions investigated the feasibility of measuring the effect in vivo. Four of the five subjects showed the expected change and that the muscle contraction times calculated using the average grayscale echo intensity change compared favorably with the times calculated based on the force data. Finally an AE pilot study with patients who had rotator cuff tendon tears found that controlling the applied load and the US view of the system will be crucial to a successful in vivo study.

  20. Ultrasonographic assessment of the equine palmar tendons

    PubMed Central

    Padaliya, N. R.; Ranpariya, J. J.; Kumar, Dharmendra; Javia, C. B.; Barvalia, D. R.

    2015-01-01

    Aim: The present study was conducted to evaluate the equine palmar tendon by ultrasonography (USG) in standing the position. Materials and Methods: USG of palmar tendons was performed in 40 adult horses using linear transducer having frequency of 10-18 MHz (e-soate, My Lab FIVE) and L52 linear array transducer (Titan, SonoSite) with frequencies ranging from 8 to 10 MHz. Palmar tendon was divided into 7 levels from distal to accessory carpal bone up to ergot in transverse scanning and 3 levels in longitudinal scanning. Results: The USG evaluation was very useful for diagnosis of affections of the conditions such as chronic bowed tendon, suspensory ligament desmitis, carpal sheath tenosynovitis and digital sheath effusions. The mean cross-sectional area (cm2) of affected tendons was significantly increased in affected than normal tendons. The echogenicity was also found reduced in affected tendons and ligaments along with disorganization of fiber alignment depending on the severity of lesion and injury. Conclusion: USG proved ideal diagnostic tool for diagnosis and post-treatment healing assessment of tendon injuries in horses. PMID:27047074

  1. Joint Angular Velocity in Spastic Gait and the Influence of Muscle-Tendon Lengthening*

    PubMed Central

    GRANATA, KEVIN P.; ABEL, MARK F.; DAMIANO, DIANE L.

    2006-01-01

    Background Joint angular velocity (the rate of flexion and extension of a joint) is related to the dynamics of muscle activation and force generation during walking. Therefore, the goal of this research was to examine the joint angular velocity in normal and spastic gait and changes resulting from muscle-tendon lengthening (recession and tenotomy) in patients who have spastic cerebral palsy. Methods The gait patterns of forty patients who had been diagnosed with spastic cerebral palsy (mean age, 8.3 years; range, 3.7 to 14.8 years) and of seventy-three age-matched, normally developing subjects were evaluated with three-dimensional motion analysis and electromyography. The patients who had cerebral palsy were evaluated before muscle-tendon lengthening and nine months after treatment. Results The gait patterns of the patients who had cerebral palsy were characterized by increased flexion of the knee in the stance phase, premature plantar flexion of the ankle, and reduced joint angular velocities compared with the patterns of the normally developing subjects. Even though muscle-tendon lengthening altered sagittal joint angles in gait, the joint angular velocities were generally unchanged at the hip and knee. Only the ankle demonstrated modified angular velocities, including reduced dorsiflexion velocity at foot-strike and improved dorsiflexion velocity through midstance, after treatment. Electromyographic changes included reduced amplitude of the gastrocnemius-soleus during the loading phase and decreased knee coactivity (the ratio of quadriceps and hamstring activation) at toe-off. Principal component analyses showed that, compared with joint-angle data, joint angular velocity was better able to discriminate between the gait patterns of the normal and cerebral palsy groups. Conclusions This study showed that muscle-tendon lengthening corrects biomechanical alignment as reflected by changes in sagittal joint angles. However, joint angular velocity and

  2. Blood supply of the Achilles tendon.

    PubMed

    Ahmed, I M; Lagopoulos, M; McConnell, P; Soames, R W; Sefton, G K

    1998-09-01

    The Achilles tendon is one of the most common sites of injury and rupture as a result of overuse. Evidence suggests that the pathogenesis of rupture could involve the pattern of its blood supply. With use of angiographic and histological techniques, the blood supply of the Achilles tendon was investigated in 12 human cadaveric specimens. Angiography confirmed Mayer's 1916 finding that the blood supply to the tendon is from three areas: the musculotendinous and osseotendinous junctions and the paratenon, with the posterior tibial artery providing the major contribution. However, qualitative and quantitative histological analyses in this study showed that the Achilles tendon has a poor blood supply throughout its length, as determined by the small number of blood vessels per cross-sectional area, which do not in general vary significantly along its length. In light of these findings, it is suggested that poor vascularity may prevent adequate tissue repair following trauma, leading to further weakening of the tendon. PMID:9820283

  3. Tendon Vasculature in Health and Disease

    PubMed Central

    Tempfer, Herbert; Traweger, Andreas

    2015-01-01

    Tendons represent a bradytrophic tissue which is poorly vascularized and, compared to bone or skin, heal poorly. Usually, a vascularized connective scar tissue with inferior functional properties forms at the injury site. Whether the increased vascularization is the root cause of tissue impairments such as loss of collagen fiber orientation, ectopic formation of bone, fat or cartilage, or is a consequence of these pathological changes remains unclear. This review provides an overview of the role of tendon vasculature in healthy and chronically diseased tendon tissue as well as its relevance for tendon repair. Further, the nature and the role of perivascular tendon stem/progenitor cells residing in the vascular niche will be discussed and compared to multipotent stromal cells in other tissues. PMID:26635616

  4. Mathematical modeling of ligaments and tendons.

    PubMed

    Woo, S L; Johnson, G A; Smith, B A

    1993-11-01

    Ligaments and tendons serve a variety of important functions in maintaining the structure of the human body. Although abundant literature exists describing experimental investigations of these tissues, mathematical modeling of ligaments and tendons also contributes significantly to understanding their behavior. This paper presents a survey of developments in mathematical modeling of ligaments and tendons over the past 20 years. Mathematical descriptions of ligaments and tendons are identified as either elastic or viscoelastic, and are discussed in chronological order. Elastic models assume that ligaments and tendons do not display time dependent behavior and thus, they focus on describing the nonlinear aspects of their mechanical response. On the other hand, viscoelastic models incorporate time dependent effects into their mathematical description. In particular, two viscoelastic models are discussed in detail; quasi-linear viscoelasticity (QLV), which has been widely used in the past 20 years, and the recently proposed single integral finite strain (SIFS) model. PMID:8302027

  5. Ultrasonic evaluation of flood gate tendons

    SciTech Connect

    Thomas, G.; Brown, A.

    1997-10-01

    Our water resources infrastructure is susceptible to aging degradation just like the rest of this country`s infrastructure. A critical component of the water supply system is the flood gate that controls the outflow from dams.Long steel rods called tendons attach these radial gates to the concrete in the dam. The tendons are typically forty feet long and over one inch in diameter. Moisture may seep into the grout around the tendons and cause corrosion. Lawrence Livermore National Laboratory is working with the California Department of Water Resources to develop advanced ultrasonic techniques for nondestructively inspecting their tendons. A unique transducer was designed and fabricated to interrogate the entire tendon. A robust,portable unit was assembled that included a computer controlled data acquisition system and specialized data processing software to analyze the ultrasonic signals. This system was tested on laboratory specimens and is presently being fielded at two dam sites.

  6. Subscapularis Tendon Repair Using Suture Bridge Technique

    PubMed Central

    Park, Yong Bok; Park, Young Eun; Koh, Kyoung Hwan; Lim, Tae Kang; Shon, Min Soo; Yoo, Jae Chul

    2015-01-01

    The subscapularis tendon plays an essential role in shoulder function. Although subscapularis tendon tears are less common than other rotator cuff tears, tears of the subscapularis tendon have increasingly been recognized with the advent of magnetic resonance imaging and arthroscopy. A suture bridge technique for the treatment of posterosuperior rotator cuff tears has provided the opportunity to improve the pressurized contact area and mean footprint pressure. However, suture bridge fixation of subscapularis tendon tears appears to be technically challenging. We describe an arthroscopic surgical technique for suture bridge repair of subscapularis tendon tears that obtains ideal cuff integrity and footprint restoration. Surgery using such a suture bridge technique is indicated for large tears, such as tears involving the entire first facet or more, tears with a disrupted lateral sling, and combined medium to large supraspinatus/infraspinatus tears. PMID:26052489

  7. Articular Cartilage Increases Transition Zone Regeneration in Bone-tendon Junction Healing

    PubMed Central

    Qin, Ling; Lee, Kwong Man; Leung, Kwok Sui

    2008-01-01

    The fibrocartilage transition zone in the direct bone-tendon junction reduces stress concentration and protects the junction from failure. Unfortunately, bone-tendon junctions often heal without fibrocartilage transition zone regeneration. We hypothesized articular cartilage grafts could increase fibrocartilage transition zone regeneration. Using a goat partial patellectomy repair model, autologous articular cartilage was harvested from the excised distal third patella and interposed between the residual proximal two-thirds bone fragment and tendon during repair in 36 knees. We evaluated fibrocartilage transition zone regeneration, bone formation, and mechanical strength after repair at 6, 12, and 24 weeks and compared them with direct repair. Autologous articular cartilage interposition resulted in more fibrocartilage transition zone regeneration (69.10% ± 14.11% [mean ± standard deviation] versus 8.67% ± 7.01% at 24 weeks) than direct repair at all times. There was no difference in the amount of bone formation and mechanical strength achieved. Autologous articular cartilage interposition increases fibrocartilage transition zone regeneration in bone-tendon junction healing, but additional research is required to ascertain the mechanism of stimulation and to establish the clinical applicability. PMID:18987921

  8. The Role of Detraining in Tendon Mechanobiology

    PubMed Central

    Frizziero, Antonio; Salamanna, Francesca; Della Bella, Elena; Vittadini, Filippo; Gasparre, Giuseppe; Nicoli Aldini, Nicolò; Masiero, Stefano; Fini, Milena

    2016-01-01

    Introduction: Several conditions such as training, aging, estrogen deficiency and drugs could affect the biological and anatomo-physiological characteristics of the tendon. Additionally, recent preclinical and clinical studies examined the effect of detraining on tendon, showing alterations in its structure and morphology and in tenocyte mechanobiology. However, few data evaluated the importance that cessation of training might have on tendon. Basically, we do not fully understand how tendons react to a phase of training followed by sudden detraining. Therefore, within this review, we summarize the studies where tendon detraining was examined. Materials and Methods: A descriptive systematic literature review was carried out by searching three databases (PubMed, Scopus and Web of Knowledge) on tendon detraining. Original articles in English from 2000 to 2015 were included. In addition, the search was extended to the reference lists of the selected articles. A public reference manager (www.mendeley.com) was adopted to remove duplicate articles. Results: An initial literature search yielded 134 references (www.pubmed.org: 53; www.scopus.com: 11; www.webofknowledge.com: 70). Fifteen publications were extracted based on the title for further analysis by two independent reviewers. Abstracts and complete articles were after that reviewed to evaluate if they met inclusion criteria. Conclusions: The revised literature comprised four clinical studies and an in vitro and three in vivo reports. Overall, the results showed that tendon structure and properties after detraining are compromised, with an alteration in the tissue structural organization and mechanical properties. Clinical studies usually showed a lesser extent of tendon alterations, probably because preclinical studies permit an in-depth evaluation of tendon modifications, which is hard to perform in human subjects. In conclusion, after a period of sudden detraining (e.g., after an injury), physical activity should

  9. Is the Modified Tardieu Scale in Semi-Standing Position Better Associated with Knee Extension and Hamstring Activity in Terminal Swing than the Supine Tardieu?

    ERIC Educational Resources Information Center

    Faber, Irene R.; Nienhuis, Bart; Rijs, Nique P. A. M.; Geurts, Alexander C. H.; Duysens, Jacques

    2008-01-01

    The aim of this study was to investigate whether the modified Tardieu scale (MTS) in a semi-standing position, used for the assessment of hamstrings spasticity, was better associated with knee extension and hamstrings activity in terminal swing than the MTS in a supine position in children with cerebral palsy (CP). Seven children diagnosed with…

  10. Tissue specificity in rat peripheral nerve regeneration through combined skeletal muscle and vein conduit grafts.

    PubMed

    Tos, P; Battiston, B; Geuna, S; Giacobini-Robecchi, M G; Hill, M A; Lanzetta, M; Owen, E R

    2000-01-01

    Diffusible factors from the distal stumps of transected peripheral nerves exert a neurotropic effect on regenerating nerves in vivo (specificity). This morphological study was designed to investigate the existence of tissue specificity in peripheral nerve fiber regeneration through a graft of vein filled with fresh skeletal muscle. This tubulization technique demonstrated experimental and clinical results similar to those obtained with traditional autologous nerve grafts. Specifically, we used Y-shaped grafts to assess the orientation pattern of regenerating axons in the distal stump tissue. Animal models were divided into four experimental groups. The proximal part of the Y-shaped conduit was sutured to a severed tibial nerve in all experiments. The two distal stumps were sutured to different targets: group A to two intact nerves (tibial and peroneal), group B to an intact nerve and an unvascularized tendon, group C to an intact nerve and a vascularized tendon, and group D to a nerve graft and an unvascularized tendon. Morphological evaluation by light and electron microscopy was conducted in the distal forks of the Y-shaped tube. Data showed that almost all regenerating nerve fibers spontaneously oriented towards the nerve tissue (attached or not to the peripheral innervation field), showing a good morphological pattern of regeneration in both the early and late phases of regeneration. When the distal choice was represented by a tendon (vascularized or not), very few nerve fibers were detected in the corresponding distal fork of the Y-shaped graft. These results show that, using the muscle-vein-combined grafting technique, regenerating axons are able to correctly grow and orientate within the basement membranes of the graft guided by the neurotropic lure of the distal nerve stump. PMID:10702739

  11. Functional Tissue Engineering of Tendon: Establishing Biological Success Criteria for Improving Tendon Repair

    PubMed Central

    Breidenbach, Andrew P; Gilday, Steven D; Lalley, Andrea L; Dyment, Nathaniel A; Gooch, Cynthia; Shearn, Jason T; Butler, David L

    2013-01-01

    Improving tendon repair using Functional Tissue Engineering (FTE) principles has been the focus of our laboratory over the last decade. Although our primary goals were initially focused only on mechanical outcomes, we are now carefully assessing the biological properties of our tissue-engineered tendon repairs so as to link biological influences with mechanics. However, given the complexities of tendon development and healing, it remains challenging to determine which aspects of tendon biology are the most important to focus on in the context of tissue engineering. To address this problem, we have formalized a strategy to identify, prioritize, and evaluate potential biological success criteria for tendon repair. We have defined numerous biological properties of normal tendon relative to cellular phenotype, extracellular matrix and tissue ultra-structure that we would like to reproduce in our tissue-engineered repairs and prioritized these biological criteria by examining their relative importance during both normal development and natural tendon healing. Here, we propose three specific biological criteria which we believe are essential for normal tendon function: 1) scleraxis-expressing cells; 2) well-organized and axially-aligned collagen fibrils having bimodal diameter distribution; and 3) a specialized tendon-to-bone insertion site. Moving forward, these biological success criteria will be used in conjunction with our already established mechanical success criteria to evaluate the effectiveness of our tissue-engineered tendon repairs. PMID:24200342

  12. Is higher serum cholesterol associated with altered tendon structure or tendon pain? A systematic review

    PubMed Central

    Tilley, Benjamin J; Cook, Jill L; Docking, Sean I; Gaida, James E

    2015-01-01

    Background Tendon pain occurs in individuals with extreme cholesterol levels (familial hypercholesterolaemia). It is unclear whether the association with tendon pain is strong with less extreme elevations of cholesterol. Objective To determine whether lipid levels are associated with abnormal tendon structure or the presence of tendon pain. Methods We conducted a systematic review and meta-analysis. Relevant articles were found through an electronic search of 6 medical databases—MEDLINE, Cochrane, AMED, EMBASE, Web of Science and Scopus. We included all case–control or cross-sectional studies with data describing (1) lipid levels or use of lipid-lowering drugs and (2) tendon structure or tendon pain. Results 17 studies (2612 participants) were eligible for inclusion in the review. People with altered tendon structure or tendon pain had significantly higher total cholesterol, low-density lipoprotein cholesterol and triglycerides, as well as lower high-density lipoprotein cholesterol; with mean difference values of 0.66, 1.00, 0.33, and −0.19 mmol/L, respectively. Conclusions The results of this review indicate that a relationship exists between an individual’s lipid profile and tendon health. However, further longitudinal studies are required to determine whether a cause and effect relationship exists between tendon structure and lipid levels. This could lead to advancement in the understanding of the pathoaetiology and thus treatment of tendinopathy. PMID:26474596

  13. Functional tissue engineering of tendon: Establishing biological success criteria for improving tendon repair.

    PubMed

    Breidenbach, Andrew P; Gilday, Steven D; Lalley, Andrea L; Dyment, Nathaniel A; Gooch, Cynthia; Shearn, Jason T; Butler, David L

    2014-06-27

    Improving tendon repair using Functional Tissue Engineering (FTE) principles has been the focus of our laboratory over the last decade. Although our primary goals were initially focused only on mechanical outcomes, we are now carefully assessing the biological properties of our tissue-engineered tendon repairs so as to link biological influences with mechanics. However, given the complexities of tendon development and healing, it remains challenging to determine which aspects of tendon biology are the most important to focus on in the context of tissue engineering. To address this problem, we have formalized a strategy to identify, prioritize, and evaluate potential biological success criteria for tendon repair. We have defined numerous biological properties of normal tendon relative to cellular phenotype, extracellular matrix and tissue ultra-structure that we would like to reproduce in our tissue-engineered repairs and prioritized these biological criteria by examining their relative importance during both normal development and natural tendon healing. Here, we propose three specific biological criteria which we believe are essential for normal tendon function: (1) scleraxis-expressing cells; (2) well-organized and axially-aligned collagen fibrils having bimodal diameter distribution; and (3) a specialized tendon-to-bone insertion site. Moving forward, these biological success criteria will be used in conjunction with our already established mechanical success criteria to evaluate the effectiveness of our tissue-engineered tendon repairs. PMID:24200342

  14. Achilles tendon: US diagnosis of pathologic conditions. Work in progress

    SciTech Connect

    Blei, C.L.; Nirschl, R.P.; Grant, E.G.

    1986-06-01

    Twenty-three patients were prospectively examined with ultra-sound (US) for acute or recurrent Achilles tendon symptoms. Three types of pathologic conditions of the Achilles tendon were found: tendinitis/tenosynovitis, acute tendon trauma, and postoperative changes. US appears to enable differentiation of these conditions and to contribute to the diagnosis of a broad range of Achilles tendon disorders.

  15. An investigation of the action of the hamstring muscles during standing in crouch using functional electrical stimulation (FES).

    PubMed

    Stewart, C; Postans, N; Schwartz, M H; Rozumalski, A; Roberts, A P

    2008-10-01

    The hamstring muscle moment arms indicate that they act as hip extensors and knee flexors. Previous work using induced acceleration (IA) analysis and functional electrical stimulation (FES) has, however, revealed counter-intuitive muscle actions, particularly for biarticular muscles during the stance phase of normal gait. In conditions such as cerebral palsy the hamstrings have been associated with the development of pathological gait patterns, particularly crouch gait. This study examines the role of these muscles in the control of crouched standing postures. Five unimpaired adult subjects had their muscles stimulated during quiet standing in different degrees of crouch. Kinematic and kinetic changes were observed and measured using a 3D motion analysis system. The hamstring muscles were shown to act strongly to retrovert the pelvis and extend the hip. The action at the knee changes as crouch increases, moving from flexing to extending. PMID:18579383

  16. Recurrent hamstring muscle injury: applying the limited evidence in the professional football setting with a seven-point programme.

    PubMed

    Brukner, Peter; Nealon, Andrew; Morgan, Christopher; Burgess, Darren; Dunn, Andrew

    2014-06-01

    Recurrent hamstring injuries are a major problem in sports such as football. The aim of this paper was to use a clinical example to describe a treatment strategy for the management of recurrent hamstring injuries and examine the evidence for each intervention. A professional footballer sustained five hamstring injuries in a relatively short period of time. The injury was managed successfully with a seven-point programme-biomechanical assessment and correction, neurodynamics, core stability, eccentric strengthening, an overload running programme, injection therapies and stretching/relaxation. The evidence for each of these treatment options is reviewed. It is impossible to be definite about which aspects of the programme contributed to a successful outcome. Only limited evidence is available in most cases; therefore, decisions regarding the use of different treatment modalities must be made by using a combination of clinical experience and research evidence. PMID:23322894

  17. Recurrent hamstring muscle injury: applying the limited evidence in the professional football setting with a seven-point programme

    PubMed Central

    Brukner, Peter; Nealon, Andrew; Morgan, Christopher; Burgess, Darren; Dunn, Andrew

    2014-01-01

    Recurrent hamstring injuries are a major problem in sports such as football. The aim of this paper was to use a clinical example to describe a treatment strategy for the management of recurrent hamstring injuries and examine the evidence for each intervention. A professional footballer sustained five hamstring injuries in a relatively short period of time. The injury was managed successfully with a seven-point programme—biomechanical assessment and correction, neurodynamics, core stability, eccentric strengthening, an overload running programme, injection therapies and stretching/relaxation. The evidence for each of these treatment options is reviewed. It is impossible to be definite about which aspects of the programme contributed to a successful outcome. Only limited evidence is available in most cases; therefore, decisions regarding the use of different treatment modalities must be made by using a combination of clinical experience and research evidence. PMID:23322894

  18. Role of biomechanics in the understanding of normal, injured, and healing ligaments and tendons

    PubMed Central

    Jung, Ho-Joong; Fisher, Matthew B; Woo, Savio L-Y

    2009-01-01

    Ligaments and tendons are soft connective tissues which serve essential roles for biomechanical function of the musculoskeletal system by stabilizing and guiding the motion of diarthrodial joints. Nevertheless, these tissues are frequently injured due to repetition and overuse as well as quick cutting motions that involve acceleration and deceleration. These injuries often upset this balance between mobility and stability of the joint which causes damage to other soft tissues manifested as pain and other morbidity, such as osteoarthritis. The healing of ligament and tendon injuries varies from tissue to tissue. Tendinopathies are ubiquitous and can take up to 12 months for the pain to subside before one could return to normal activity. A ruptured medial collateral ligament (MCL) can generally heal spontaneously; however, its remodeling process takes years and its biomechanical properties remain inferior when compared to the normal MCL. It is also known that a midsubstance anterior cruciate ligament (ACL) tear has limited healing capability, and reconstruction by soft tissue grafts has been regularly performed to regain knee function. However, long term follow-up studies have revealed that 20–25% of patients experience unsatisfactory results. Thus, a better understanding of the function of ligaments and tendons, together with knowledge on their healing potential, may help investigators to develop novel strategies to accelerate and improve the healing process of ligaments and tendons. With thousands of new papers published in the last ten years that involve biomechanics of ligaments and tendons, there is an increasing appreciation of this subject area. Such attention has positively impacted clinical practice. On the other hand, biomechanical data are complex in nature, and there is a danger of misinterpreting them. Thus, in these review, we will provide the readers with a brief overview of ligaments and tendons and refer them to appropriate methodologies used to

  19. Tendon rupture associated with simvastatin/ezetimibe therapy.

    PubMed

    Pullatt, Raja C; Gadarla, Mamatha Reddy; Karas, Richard H; Alsheikh-Ali, Alawi A; Thompson, Paul D

    2007-07-01

    A case of spontaneous biceps tendon rupture in a physician during therapy with the combination of simvastatin and ezetimibe (Vytorin) is reported. Rechallenge produced tendinopathy in the contralateral biceps tendon that abated with drug discontinuation. Tendon rupture generally occurs in injured tendons. Physiological repair of an injured tendon requires degradation and remodeling of the extracellular matrix through matrix metalloproteinases (MMPs). Statins are known to inhibit MMPs. It was hypothesized that statins may increase the risk of tendon rupture by altering MMP activity. In conclusion, statins may increase the risk of tendon rupture by altering MMP activity. PMID:17599460

  20. Effectiveness of injury prevention programs on developing quadriceps and hamstrings strength of young male professional soccer players.

    PubMed

    Daneshjoo, Abdolhamid; Rahnama, Nader; Mokhtar, Abdul Halim; Yusof, Ashril

    2013-12-18

    Muscular strength is an important factor which is crucial for performance and injury prevention in most sports. The purpose of this study was to evaluate the effects of the FIFA's Medical Assessment and Research Centre 11+ and HarmoKnee injury prevention programs on knee strength of young professional male soccer players. Thirty-six soccer players (age: 18.9 ± 1.4 years) were divided equally into three groups; the 11+, HarmoKnee and control groups. The programs were performed for 24 sessions. Hamstring and quadriceps strength was measured using the Biodex System 3 at 30°, 60° and 90° of knee flexion. The 11+ increased quadriceps strength in the dominant leg by 19.7% and 47.8% at 60°and 90° knee flexion, respectively, and in the non-dominant leg by 16%, 35.3% and 78.1 % at 30°, 60° and 90° knee flexion, respectively. The HarmoKnee group, however, showed increased quadriceps strength only at 90° i.e., by 85.7% in the dominant leg and 73.8% in the non-dominant leg. As for hamstring strength, only the 11+ group demonstrated an increment by 24.8% and 19.8% at 30° and 60° knee flexion in the dominant leg, and in the non-dominant leg, by 28.7% and 13.7% at 30° and 60° knee flexion, respectively. In conclusion, both warm-up programs improve quadriceps strength. The 11+ demonstrated improvement in hamstring strength while the HarmoKnee program did not indicate any improvement. We suggest adding eccentric hamstring components such as Nordic hamstring exercise to the HarmoKnee program in order to enhance hamstring strength. PMID:24511347

  1. Effect of modified hold-relax stretching and static stretching on hamstring muscle flexibility

    PubMed Central

    Ahmed, Hashim; Iqbal, Amir; Anwer, Shahnawaz; Alghadir, Ahmad

    2015-01-01

    [Purpose] The aim of present study was to compare the effectiveness of modified hold-relax stretching and static stretching in improving the hamstring muscle flexibility. [Subjects and Methods] Forty-five male subjects with hamstring tightness were included in this study. The subjects were randomly placed into three groups: the modified hold-relax stretching, static stretching and control groups. The modified hold-relax stretching group performed 7 seconds of isometric contraction and then relaxed for 5 seconds, and this was repeated five times daily for five consecutive days. The static stretching group received 10 minutes of static stretching with the help of a pulley and weight system for five consecutive days. The control group received only moist heat for 20 minutes for five consecutive days. A baseline reading of passive knee extension (PKE) was taken prior to the intervention; rest measurements were taken immediate post intervention on day 1, day 3, day 5, and after a 1 week follow-up, i.e., at the 12th day. [Results] On comparing the baseline readings of passive knee extension (PKE), there was no difference noted between the three groups. On comparing the posttest readings on day 5 between the 3 groups, a significant difference was noted. However, post hoc analysis revealed an insignificant difference between the modified hold-relax stretching and static stretching groups. There was a significant difference between the static stretching and control groups and between the modified hold-relax stretching and control groups. [Conclusion] The results of this study indicate that both the modified hold-relax stretching technique and static stretching are equally effective, as there was no significant difference in improving the hamstring muscle flexibility between the two groups. PMID:25729210

  2. A comparison of two stretching programs for hamstring muscles: A randomized controlled assessor-blinded study.

    PubMed

    Demoulin, Christophe; Wolfs, Sébastien; Chevalier, Madeline; Granado, Caroline; Grosdent, Stéphanie; Depas, Yannick; Roussel, Nathalie; Hage, Renaud; Vanderthommen, Marc

    2016-01-01

    Most parameters regarding hamstring flexibility training programs have been investigated; however, the joint (i.e. hip or knee) on which the stretching should preferentially be focused needs to be further explored. This randomized controlled assessor-blinded study aimed to investigate the influence of this parameter. We randomly assigned 111 asymptomatic participants with tight hamstring muscles in three groups: a control group and two groups following a different home-based 8-week (five 10-minute sessions per week) hamstring stretching program (i.e. stretching performed by flexing the hip while keeping the knee extended [SH] or by first flexing the hip with a flexed knee and then extending the knee [SK]). Range of motion (ROM) of hip flexion and knee extension were measured before and after the stretching program by means of the straight leg raising test and the passive knee extension angle test, respectively. Eighty-nine participants completed the study. A significant increase in ROM was observed at post-test. Analyses showed significant group-by-time interactions for changes regarding all outcomes. Whereas the increase in hip flexion and knee extension ROM was higher in the stretching groups than in the CG (especially for the SH group p < 0.05), no differences between the two stretching groups were observed (p > 0.05). In conclusion, the fact that both stretching programs resulted in similar results suggests no influence of the joint at which the stretching is focused upon, as assessed by the straight leg raising and knee extension angle tests. PMID:26756214

  3. Viscoelasticity of Tendons Under Transverse Compression.

    PubMed

    Paul Buckley, C; Samuel Salisbury, S T; Zavatsky, Amy B

    2016-10-01

    Tendons are highly anisotropic and also viscoelastic. For understanding and modeling their 3D deformation, information is needed on their viscoelastic response under off-axis loading. A study was made, therefore, of creep and recovery of bovine digital extensor tendons when subjected to transverse compressive stress of up to ca. 100 kPa. Preconditioned tendons were compression tested between glass plates at increasing creep loads. The creep response was anomalous: the relative rate of creep reduced with the increasing stress. Over each ca. 100 s creep period, the transverse creep deformation of each tendon obeyed a power law dependence on time, with the power law exponent falling from ca. 0.18 to an asymptote of ca. 0.058 with the increasing stress. A possible explanation is stress-driven dehydration, as suggested previously for the similar anomalous behavior of ligaments. Recovery after removal of each creep load was also anomalous. Relative residual strain reduced with the increasing creep stress, but this is explicable in terms of the reducing relative rate of creep. When allowance was made for some adhesion occurring naturally between tendon and the glass plates, the results for a given load were consistent with creep and recovery being related through the Boltzmann superposition principle (BSP). The tendon tissue acted as a pressure-sensitive adhesive (PSA) in contact with the glass plates: explicable in terms of the low transverse shear modulus of the tendons. PMID:27496279

  4. Male and female runners demonstrate different sagittal plane mechanics as a function of static hamstring flexibility

    PubMed Central

    Williams III, D. S. Blaise; Welch, Lee M.

    2015-01-01

    ABSTRACT Background: Injuries to runners are common. However, there are many potential contributing factors to injury. While lack of flexibility alone is commonly related to injury, there are clear differences in hamstring flexibility between males and females. Objective: To compare the effect of static hamstring length on sagittal plane mechanics between male and female runners. Method: Forty subjects (30.0±6.4 years) participated and were placed in one of 4 groups: flexible males (n=10), inflexible males (n=10), flexible females (n=10), and inflexible females (n=10). All subjects were free of injury at the time of data collection. Three-dimensional kinematics and kinetics were collected while subjects ran over ground across 2 force platforms. Sagittal plane joint angles and moments were calculated at the knee and hip and compared with a 2-way (sex X flexibility) ANOVA (α=0.05). Results: Males exhibited greater peak knee extension moment than females (M=2.80±0.47, F=2.48±0.52 Nm/kg*m, p=0.05) and inflexible runners exhibited greater peak knee extension moment than flexible runners (In=2.83±0.56, Fl=2.44±0.51 Nm/kg*m, p=0.01). For hip flexion at initial contact, a significant interaction existed (p<0.05). Flexible females (36.7±7.4º) exhibited more hip flexion than inflexible females (27.9±4.6º, p<0.01) and flexible males (30.1±9.5º, p<0.05). No differences existed for knee angle at initial contact, peak knee angle, peak hip angle, or peak hip moment. Conclusion: Hamstring flexibility results in different mechanical profiles in males and females. Flexibility in the hamstrings may result in decreased moments via active or passive tension. These differences may have implications for performance and injury in flexible female runners. PMID:26537812

  5. Radioprotection provides functional mechanics but delays healing of irradiated tendon allografts after ACL reconstruction in sheep.

    PubMed

    Seto, Aaron U; Culp, Brian M; Gatt, Charles J; Dunn, Michael

    2013-12-01

    Successful protection of tissue properties against ionizing radiation effects could allow its use for terminal sterilization of musculoskeletal allografts. In this study we functionally evaluate Achilles tendon allografts processed with a previously developed radioprotective treatment based on (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide) crosslinking and free radical scavenging using ascorbate and riboflavin, for ovine anterior cruciate ligament reconstruction. Arthroscopic anterior cruciate ligament (ACL) reconstruction was performed using double looped allografts, while comparing radioprotected irradiated and fresh frozen allografts after 12 and 24 weeks post-implantation, and to control irradiated grafts after 12 weeks. Radioprotection was successful at preserving early subfailure mechanical properties comparable to fresh frozen allografts. Twelve week graft stiffness and anterior-tibial (A-T) translation for radioprotected and fresh frozen allografts were comparable at 30 % of native stiffness, and 4.6 and 5 times native A-T translation, respectively. Fresh frozen allograft possessed the greatest 24 week peak load at 840 N and stiffness at 177 N/mm. Histological evidence suggested a delay in tendon to bone healing for radioprotected allografts, which was reflected in mechanical properties. There was no evidence that radioprotective treatment inhibited intra-articular graft healing. This specific radioprotective method cannot be recommended for ACL reconstruction allografts, and data suggest that future efforts to improve allograft sterilization procedures should focus on modifying or eliminating the pre-crosslinking procedure. PMID:23842952

  6. Les plaies du tendon patellaire

    PubMed Central

    Mechchat, Atif; Elidrissi, Mohammed; Mardy, Abdelhak; Elayoubi, Abdelghni; Shimi, Mohammed; Elibrahimi, Abdelhalim; Elmrini, Abdelmajid

    2014-01-01

    Les plaies du tendon patellaire sont peu fréquentes et sont peu rapportés dans la littérature, contrairement aux ruptures sous cutanées. Les sections du tendon patellaire nécessitent une réparation immédiate afin de rétablir l'appareil extenseur et de permettre une récupération fonctionnelle précoce. A travers ce travail rétrospectif sur 13 cas, nous analysons les aspects épidémiologiques, thérapeutiques et pronostiques de ce type de pathologie en comparant différents scores. L’âge moyen est de 25 ans avec une prédominance masculine. Les étiologies sont dominées par les accidents de la voie publique (68%) et les agressions par agent tranchant (26%) et contendant (6 %). Tous nos patients ont bénéficié d'un parage chirurgical avec suture tendineuse direct protégée par un laçage au fils d'aciers en légère flexion. La rééducation est débutée après sédation des phénomènes inflammatoires. Au dernier recul les résultats sont excellents et bon à 92%. Nous n'avons pas noté de différence de force musculaire et d'amplitude articulaire entre le genou sain et le genou lésé. Les lésions ouvertes du tendon patellaire est relativement rare. La prise en charge chirurgicale rapide donne des résultats assez satisfaisants. La réparation est généralement renforcée par un semi-tendineux, synthétique ou métallique en forme de cadre de renfort pour faciliter la réadaptation et réduire le risque de récidive après la fin de l'immobilisation. PMID:25170379

  7. Tendon-Holding Capacities of Two Newly Designed Implants for Tendon Repair: An Experimental Study on the Flexor Digitorum Profundus Tendon of Sheep

    PubMed Central

    Ağır, İsmail; Aytekin, Mahmut Nedim; Başçı, Onur; Çaypınar, Barış; Erol, Bülent

    2014-01-01

    Background: Two main factors determine the strength of tendon repair; the tensile strength of material and the gripping capacity of a suture configuration. Different repair techniques and suture materials were developed to increase the strength of repairs but none of techniques and suture materials seem to provide enough tensile strength with safety margins for early active mobilization. In order to overcome this problem tendon suturing implants are being developed. We designed two different suturing implants. The aim of this study was to measure tendon-holding capacities of these implants biomechanically and to compare them with frequently used suture techniques Materials and Methods: In this study we used 64 sheep flexor digitorum profundus tendons. Four study groups were formed and each group had 16 tendons. We applied model 1 and model 2 implant to the first 2 groups and Bunnell and locking-loop techniques to the 3rd and 4th groups respectively by using 5 Ticron sutures. Results: In 13 tendons in group 1 and 15 tendons in group 2 and in all tendons in group 3 and 4, implants and sutures pulled out of the tendon in longitudinal axis at the point of maximum load. The mean tensile strengths were the largest in group 1 and smallest in group 3. Conclusion: In conclusion, the new stainless steel tendon suturing implants applied from outside the tendons using steel wires enable a biomechanically stronger repair with less tendon trauma when compared to previously developed tendon repair implants and the traditional suturing techniques. PMID:25067965

  8. An insight on multiscale tendon modeling in muscle-tendon integrated behavior.

    PubMed

    Maceri, Franco; Marino, Michele; Vairo, Giuseppe

    2012-03-01

    This paper aims to highlight the need for a refined tendon model to reproduce the main mechanical features of the integrated muscle-tendon unit (MTU). Elastic nonlinearities of the tendon, both at the nano and microscale, are modeled by a multiscale approach, accounting for the hierarchical arrangement (from molecules up to the fibers) of the collagen structures within the tissue. This model accounts also for the variation of tendon stiffness due to physical activity. Since the proposed tendon model is based on tissue-structured histology, the training-driven adaptation laws are directly formulated starting from histological evidences. Such a tendon description is integrated into a viscoelastic Hill-type model of the whole MTU. A fixed-end contraction test is numerically simulated, and results based on both linear and nonlinear tendon elastic model are compared. Sound and effective time-histories of muscle contractile force and fiber length are obtained only accounting for tendon elastic nonlinearities, which allow to quantitatively recover some experimental data. Finally, proposed numerical results give clear indications toward a rational explanation of the influence of tendon remodeling induced by physical activity on muscular contractile force. PMID:21739087

  9. Multi-layer electrospun membrane mimicking tendon sheath for prevention of tendon adhesions.

    PubMed

    Jiang, Shichao; Yan, Hede; Fan, Dapeng; Song, Jialin; Fan, Cunyi

    2015-01-01

    Defect of the tendon sheath after tendon injury is a main reason for tendon adhesions, but it is a daunting challenge for the biomimetic substitute of the tendon sheath after injury due to its multi-layer membrane-like structure and complex biologic functions. In this study, a multi-layer membrane with celecoxib-loaded poly(l-lactic acid)-polyethylene glycol (PELA) electrospun fibrous membrane as the outer layer, hyaluronic acid (HA) gel as middle layer, and PELA electrospun fibrous membrane as the inner layer was designed. The anti-adhesion efficacy of this multi-layer membrane was compared with a single-layer use in rabbit flexor digitorum profundus tendon model. The surface morphology showed that both PELA fibers and celecoxib-loaded PELA fibers in multi-layer membrane were uniform in size, randomly arrayed, very porous, and smooth without beads. Multi-layer membrane group had fewer peritendinous adhesions and better gliding than the PELA membrane group and control group in gross and histological observation. The similar mechanical characteristic and collagen expression of tendon repair site in the three groups indicated that the multi-layer membrane did not impair tendon healing. Taken together, our results demonstrated that such a biomimetic multi-layer sheath could be used as a potential strategy in clinics for promoting tendon gliding and preventing adhesion without poor tendon healing. PMID:25822877

  10. IFSSH Flexor Tendon Committee report 2014: from the IFSSH Flexor Tendon Committee (Chairman: Jin Bo Tang).

    PubMed

    Tang, Jin Bo; Chang, James; Elliot, David; Lalonde, Donald H; Sandow, Michael; Vögelin, Esther

    2014-01-01

    Hand surgeons continue to search for the best surgical flexor tendon repair and treatment of the tendon sheaths and pulleys, and they are attempting to establish postoperative regimens that fit diverse clinical needs. It is the purpose of this report to present the current views, methods, and suggestions of six senior hand surgeons from six different countries - all experienced in tendon repair and reconstruction. Although certainly there is common ground, the report presents provocative views and approaches. The report reflects an update in the views of the committee. We hope that it is helpful to surgeons and therapists in treating flexor tendon injuries. PMID:23962872

  11. Effects of Initial Graft Tension on the Tibiofemoral Compressive Forces and Joint Position Following ACL Reconstruction

    PubMed Central

    Brady, Mark F.; Bradley, Michael P.; Fleming, Braden C.; Fadale, Paul D.; Hulstyn, Michael J.; Banerjee, Rahul

    2007-01-01

    Background The initial tension applied to an ACL graft at the time of fixation modulates knee motion and the tibiofemoral compressive loads. Purpose To establish the relationships between initial graft tension, tibiofemoral compressive force, and the neutral tibiofemoral position in the cadaver knee. Study Design Controlled Laboratory Study. Methods The tibiofemoral compressive forces and joint positions were determined in the ACL-intact knee at 0°, 20° and 90° knee flexion. The ACL was excised and reconstructed with a patellar tendon graft using graft tensions of 1, 15, 30, 60 and 90 N applied at 0°, 20° and 90° knee flexion. The compressive forces and neutral positions were compared between initial tension conditions and the ACL-intact knee. Results Increasing initial graft tension increased the tibiofemoral compressive forces. The forces in the medial compartment were 1.8 times those in the lateral compartment. The compressive forces were dependent on the knee angle at which the tension was applied. The greatest compressive forces occurred when the graft was tensioned with the knee in extension. An increase in initial graft tension caused the tibia to rotate externally compared to the ACL-intact knee. Increases in initial graft tension also caused a significant posterior translation of the tibia relative to the femur. Conclusions Different initial graft tension protocols produced predictable changes in the tibiofemoral compressive forces and joint positions. Clinical Relevance The tibiofemoral compressive force and neutral joint position were best replicated with a low graft tension (1–15 N) when using a patellar tendon graft. PMID:17218659

  12. Heel pain and Achilles tendonitis - aftercare

    MedlinePlus

    ... the length of the tendon when walking or running. Your pain and stiffness might increase in the ... or decrease activities that cause pain, such as running or jumping. Do activities that do not strain ...

  13. Pectoralis Major Tendon Repair Post Surgical Rehabilitation

    PubMed Central

    Prohaska, Dan

    2007-01-01

    Pectoralis major tendon rupture is a rare shoulder injury, most commonly seen in weight lifters. This injury is being seen more regularly due to the increased emphasis on healthy lifestyles. Surgical repair of the pectoralis major tendon rupture has been shown to provide superior outcomes regarding strength return. Thus it appears that surgical repair is the treatment of choice for those wishing to return to competitive or recreational athletic activity. This article describes the history and physical examination process for the athlete with pectoralis tendon major rupture. Surgical vs conservative treatment will be discussed. This manuscript provides post surgical treatment guidelines that can be followed after surgical repair of the pectoralis tendon rupture. PMID:21522200

  14. Position Control of Tendon-Driven Fingers

    NASA Technical Reports Server (NTRS)

    Abdallah, Muhammad E.; Platt, Robert, Jr.; Hargrave, B.; Pementer, Frank

    2011-01-01

    Conventionally, tendon-driven manipulators implement some force control scheme based on tension feedback. This feedback allows the system to ensure that the tendons are maintained taut with proper levels of tensioning at all times. Occasionally, whether it is due to the lack of tension feedback or the inability to implement sufficiently high stiffnesses, a position control scheme is needed. This work compares three position controllers for tendon-driven manipulators. A new controller is introduced that achieves the best overall performance with regards to speed, accuracy, and transient behavior. To compensate for the lack of tension feedback, the controller nominally maintains the internal tension on the tendons by implementing a two-tier architecture with a range-space constraint. These control laws are validated experimentally on the Robonaut-2 humanoid hand. I

  15. Flexor tendon repair in zone III.

    PubMed

    Al-Qattan, Mohammad M

    2011-01-01

    There is a paucity of the literature on the outcome of zone III flexor tendon injuries. In this paper, we report on the results of zone III flexor tendon repair in 35 consecutive adult patients with clean cut lacerations of both flexor tendons in 42 fingers. There were 25 men and 10 women with an average age of 32 years. Repair of both flexor tendons was performed using 'figure of eight' core sutures and a continuous epitendinous suture. Postoperatively, an immediate active range of motion protocol was applied to ensure full active extension of the interphalangeal joints. The results were assessed using the Strickland-Glogovac grading system. There were no ruptures. One patient with two injured fingers developed complex regional pain syndrome and the final outcome was fair in both fingers. In the remaining 34 patients (40 fingers), 33 patients (38 fingers) had an excellent outcome and the remaining patient (two fingers) had a good outcome. PMID:20807720

  16. [Flexor tendon repair: a short story].

    PubMed

    Moutet, F; Corcella, D; Forli, A; Mesquida, V

    2014-12-01

    This short story of flexor tendon repair aims to illustrate hesitations and wanderings of this surgery. Obviously tendon repair was very early considered, but it developed and diffused rather lately. It became a routine practice only in 20th century. This was due on the one hand, in Occident, to the Galen's dogmatic interdiction, on the other hand, to the repair difficulties of this paradoxical structure. Actually tendon is made of fibroblasts and collagen (sticky substances), and then its only goal is to move. According to this necessity, whatever the used techniques are, gliding is the final purpose. Technical evolutions are illustrated by historical contributions to flexor tendon surgery of several "giants" of hand surgery. PMID:24837978

  17. MUSCLE ACTIVATION OF THE TORSO DURING THE MODIFIED RAZOR CURL HAMSTRING EXERCISE

    PubMed Central

    Stone, Audrey J.; Wyman, James W.; Blazquez, Ivan N.

    2012-01-01

    Purpose/Background: The RAZOR curl has been introduced as a hamstring exercise. However, modifications to the exercise have been developed which are proposed to utilize some of the muscles of the lumbo-pelvic-hip complex. Thus, it was the purpose of this study to quantitatively examine the modified RAZOR curl using surface electromyography (sEMG), as an exercise that may recruit the trunk muscles of the lumbo-pelvic-hip complex. Methods: Twenty-eight active male and female graduate students (24.2±1.3 years; 174.8±9.9 cm; 74.9±14.9 kg), consented to participate. Dependent variables were muscle activation of trunk musculature (dominant side gluteus medius, gluteus maximus, multifidus, longissimus, lower rectus abdominis, upper rectus abdominis, external obliques) reported as percent of maximum voluntary isometric contraction (%MVIC) during the exercise while the independent variable was the muscle selected. Results: The multifidus and longissimus demonstrated moderately strong activation (35-50%MVIC) while the upper rectus abdominis demonstrated strong activation (20-35%MVIC) and the gluteus medius, gluteus maximus, lower rectus abdominis, and external obliques had minimal activation. Conclusions: These findings allow the practitioner to utilize an exercise that provides a functional training stimulus that activates not only the hamstrings but also some musculature of the trunk muscles of the lumbopelvic-hip complex at strong to moderately strong levels. Level of Evidence: 5 PMID:22319680

  18. Sprint Acceleration Mechanics: The Major Role of Hamstrings in Horizontal Force Production

    PubMed Central

    Morin, Jean-Benoît; Gimenez, Philippe; Edouard, Pascal; Arnal, Pierrick; Jiménez-Reyes, Pedro; Samozino, Pierre; Brughelli, Matt; Mendiguchia, Jurdan

    2015-01-01

    Recent literature supports the importance of horizontal ground reaction force (GRF) production for sprint acceleration performance. Modeling and clinical studies have shown that the hip extensors are very likely contributors to sprint acceleration performance. We experimentally tested the role of the hip extensors in horizontal GRF production during short, maximal, treadmill sprint accelerations. Torque capabilities of the knee and hip extensors and flexors were assessed using an isokinetic dynamometer in 14 males familiar with sprint running. Then, during 6-s sprints on an instrumented motorized treadmill, horizontal and vertical GRF were synchronized with electromyographic (EMG) activity of the vastus lateralis, rectus femoris, biceps femoris, and gluteus maximus averaged over the first half of support, entire support, entire swing and end-of-swing phases. No significant correlations were found between isokinetic or EMG variables and horizontal GRF. Multiple linear regression analysis showed a significant relationship (P = 0.024) between horizontal GRF and the combination of biceps femoris EMG activity during the end of the swing and the knee flexors eccentric peak torque. In conclusion, subjects who produced the greatest amount of horizontal force were both able to highly activate their hamstring muscles just before ground contact and present high eccentric hamstring peak torque capability. PMID:26733889

  19. Structure of the tendon connective tissue.

    PubMed

    Kannus, P

    2000-12-01

    Tendons consist of collagen (mostly type I collagen) and elastin embedded in a proteoglycan-water matrix with collagen accounting for 65-80% and elastin approximately 1-2% of the dry mass of the tendon. These elements are produced by tenoblasts and tenocytes, which are the elongated fibroblasts and fibrocytes that lie between the collagen fibers, and are organized in a complex hierarchical scheme to form the tendon proper. Soluble tropocollagen molecules form cross-links to create insoluble collagen molecules which then aggregate progressively into microfibrils and then into electronmicroscopically clearly visible units, the collagen fibrils. A bunch of collagen fibrils forms a collagen fiber, which is the basic unit of a tendon. A fine sheath of connective tissue called endotenon invests each collagen fiber and binds fibers together. A bunch of collagen fibers forms a primary fiber bundle, and a group of primary fiber bundles forms a secondary fiber bundle. A group of secondary fiber bundles, in turn, forms a tertiary bundle, and the tertiary bundles make up the tendon. The entire tendon is surrounded by a fine connective tissue sheath called epitenon. The three-dimensional ultrastructure of tendon fibers and fiber bundles is complex. Within one collagen fiber, the fibrils are oriented not only longitudinally but also transversely and horizontally. The longitudinal fibers do not run only parallel but also cross each other, forming spirals. Some of the individual fibrils and fibril groups form spiral-type plaits. The basic function of the tendon is to transmit the force created by the muscle to the bone, and, in this way, make joint movement possible. The complex macro- and microstructure of tendons and tendon fibers make this possible. During various phases of movements, the tendons are exposed not only to longitudinal but also to transversal and rotational forces. In addition, they must be prepared to withstand direct contusions and pressures. The above

  20. [Tendinosis and ruptures of the Achilles tendon].

    PubMed

    Amlang, M H; Zwipp, H

    2012-02-01

    Tendinosis of the Achilles tendon is a degenerative-reparative structural change of the tendon with microdefects, increases in cross-section due to cicatricial tendon regeneration, neoangiogenesis and reduction of elasticity. The previously used term tendinitis is only rarely used for the chronic form since signs of inflammation such as redness and hyperthermia or elevated levels of inflammatory parameters on laboratory testing are generally absent. Duplex sonography with visualization of the neovascularization has become a valuable supplement not only for diagnostics but also for therapy planning. The classic, conservative therapy for painful tendinosis consists of oral anti-inflammatory drugs, pain-adapted load reduction, raising the heel, stretching the calf musculature, and various physiotherapeutic interventions. When conservative treatment over a period of 4 - 6 months fails to produce any or non-adequate pain relief, an indication for surgical treatment should be considered. In the therapy for fresh ruptures of the Achilles tendon further developments in minimally invasive techniques have led to a worldwide paradigm change over the past 10 years. The decisive advantage of minimally invasive surgical techniques is the lower risk of wound infection as compared to the sutures of the open technique. When compared with conservative functional therapy the minimally invasive repair has the advantage of being less dependent on the compliance of the patient since, in the early phase of tendon healing the suture prevents a separation of the tendon ends upon controlled movements. However, not every patient with a ruptured Achilles tendon should be treated with a minimally invasive repair. Open tendon reconstruction and functional conservative therapy are still justified when the correct indication is given. PMID:22344862

  1. Dynamic ultrasound of peroneal tendon instability.

    PubMed

    Pesquer, Lionel; Guillo, Stéphane; Poussange, Nicolas; Pele, Eric; Meyer, Philippe; Dallaudière, Benjamin

    2016-07-01

    Ankle snapping may be caused by peroneal tendon instability. Anterior instability occurs after traumatic superior peroneal retinaculum injury, whereas peroneal tendon intrasheath subluxation is atraumatic. Whereas subluxation is mainly dynamic, ultrasound allows for the diagnosis and classification of peroneal instability because it allows for real-time exploration. The purpose of this review is to describe the anatomic and physiologic bases for peroneal instability and to heighten the role of dynamic ultrasound in the diagnosis of snapping. PMID:26943704

  2. Electrostrictive Graft Elastomers

    NASA Technical Reports Server (NTRS)

    Su, Ji (Inventor); Harrison, Joycelyn S. (Inventor); St.Clair, Terry L. (Inventor)

    2003-01-01

    An electrostrictive graft elastomer has a backbone molecule which is a non-crystallizable, flexible macromolecular chain and a grafted polymer forming polar graft moieties with backbone molecules. The polar graft moieties have been rotated by an applied electric field, e.g., into substantial polar alignment. The rotation is sustained until the electric field is removed. In another embodiment, a process for producing strain in an elastomer includes: (a) providing a graft elastomer having a backbone molecule which is a non-crystallizable, flexible macromolecular chain and a grafted polymer forming polar graft moieties with backbone molecules; and (b) applying an electric field to the graft elastomer to rotate the polar graft moieties, e.g., into substantial polar alignment.

  3. Randomised trial of the effects of four weeks of daily stretch on extensibility of hamstring muscles in people with spinal cord injuries.

    PubMed

    Harvey, Lisa A; Byak, Adrian J; Ostrovskaya, Marsha; Glinsky, Joanne; Katte, Lyndall; Herbert, Robert D

    2003-01-01

    The aim of this assessor-blind randomised controlled trial was to determine the effect of four weeks of 30 minute stretches each weekday on extensibility of the hamstring muscles in people with recent spinal cord injuries. A consecutive sample of 16 spinal cord-injured patients with no or minimal voluntary motor power in the lower limbs and insufficient hamstring muscle extensibility to enable optimal long sitting were recruited. Subjects' legs were randomly allocated to experimental and control conditions. The hamstring muscles of the experimental leg of each subject were stretched with a 30 Nm torque at the hip for 30 minutes each weekday for four weeks. The hamstring muscles of the contralateral leg were not stretched during this period. Extensibility of the hamstring muscles (hip flexion range of motion with knee extended, measured with a 48 Nm torque at the hip) of both legs was measured by a blinded assessor at the commencement of the study and one day after the completion of the four-week stretch period. Changes in hamstring muscle extensibility from initial to final measurements were calculated. The effect of stretching was expressed as the mean difference in these changes between stretched and non-stretched legs. The mean effect of stretching was 1 degree (95% CI -2 to 5 degrees). Four weeks of 30 minute stretches each weekday does not affect the extensibility of the hamstring muscle in people with spinal cord injuries. PMID:12952517

  4. Grasp Assist Device with Shared Tendon Actuator Assembly

    NASA Technical Reports Server (NTRS)

    Ihrke, Chris A. (Inventor); Bergelin, Bryan J. (Inventor); Bridgwater, Lyndon (Inventor)

    2015-01-01

    A grasp assist device includes a glove with first and second tendon-driven fingers, a tendon, and a sleeve with a shared tendon actuator assembly. Tendon ends are connected to the respective first and second fingers. The actuator assembly includes a drive assembly having a drive axis and a tendon hook. The tendon hook, which defines an arcuate surface slot, is linearly translatable along the drive axis via the drive assembly, e.g., a servo motor thereof. The flexible tendon is routed through the surface slot such that the surface slot divides the flexible tendon into two portions each terminating in a respective one of the first and second ends. The drive assembly may include a ball screw and nut. An end cap of the actuator assembly may define two channels through which the respective tendon portions pass. The servo motor may be positioned off-axis with respect to the drive axis.

  5. Acute Patellar Tendon Rupture after Total Knee Arthroplasty Revision

    PubMed Central

    Rhee, Seung Joon; Pham, The Hien

    2015-01-01

    Patellar tendon rupture is a catastrophic complication following total knee arthroplasty (TKA). Though revision TKA has been suspected of being a predisposing factor for the occurrence of patellar tendon rupture, there are few reports on patellar tendon rupture after revision TKA. Here, we present a case of acute patellar tendon rupture that occurred after TKA revision. In the patient, the patellar tendon was so thin and could not be repaired, and accordingly was sutured end to end. We used the anterior tibialis tendon allograft to augment the poor quality patellar tendon tissue. Fixation of the allograft was done by using the bone tunnel created through tibial tuberosity and suturing the allograft to the patellar tendon and quadriceps tendon. The patient was instructed to wear a full extension knee splint and was kept non-weight bearing for 6 weeks after operation. Full knee extension could be achieved 6 weeks postoperatively. PMID:26060612

  6. Tension Distribution in a Tendon-Driven Robotic Finger

    NASA Technical Reports Server (NTRS)

    Abdallah, Muhammad E. (Inventor); Platt, Robert (Inventor); Wampler, II, Charles W. (Inventor)

    2013-01-01

    A method is provided for distributing tension among tendons of a tendon-driven finger in a robotic system, wherein the finger characterized by n degrees of freedom and n+1 tendons. The method includes determining a maximum functional tension and a minimum functional tension of each tendon of the finger, and then using a controller to distribute tension among the tendons, such that each tendon is assigned a tension value less than the maximum functional tension and greater than or equal to the minimum functional tension. The method satisfies the minimum functional tension while minimizing the internal tension in the robotic system, and satisfies the maximum functional tension without introducing a coupled disturbance to the joint torques. A robotic system includes a robot having at least one tendon-driven finger characterized by n degrees of freedom and n+1 tendons, and a controller having an algorithm for controlling the tendons as set forth above.

  7. The cell biology of suturing tendons

    PubMed Central

    Wong, J.K.F.; Alyouha, S.; Kadler, K.E.; Ferguson, M.W.J.; McGrouther, D.A.

    2010-01-01

    Trauma by suturing tendon form areas devoid of cells termed “acellular zones” in the matrix. This study aimed to characterise the cellular insult of suturing and acellular zone formation in mouse tendon. Acellular zone formation was evaluated using single grasping sutures placed using flexor tendons with time lapse cell viability imaging for a period of 12 h. Both tension and injury were required to induce cell death and cell movement in the formation of the acellular zone. DNA fragmentation studies and transmission electron microscopy indicated that cells necrosed. Parallel in vivo studies showed that cell-to-cell contacts were disrupted following grasping by the suture in tensioned tendon. Without tension, cell death was lessened and cell-to-cell contacts remained intact. Quantitative immunohistochemistry and 3D cellular profile mapping of wound healing markers over a one year time course showed that acellular zones arise rapidly and showed no evidence of healing whilst the wound healing response occurred in the surrounding tissues. The acellular zones were also evident in a standard modified “Kessler” clinical repair. In conclusion, the suture repair of injured tendons produces acellular zones, which may potentially cause early tendon failure. PMID:20600895

  8. The cell biology of suturing tendons.

    PubMed

    Wong, J K F; Alyouha, S; Kadler, K E; Ferguson, M W J; McGrouther, D A

    2010-07-01

    Trauma by suturing tendon form areas devoid of cells termed "acellular zones" in the matrix. This study aimed to characterise the cellular insult of suturing and acellular zone formation in mouse tendon. Acellular zone formation was evaluated using single grasping sutures placed using flexor tendons with time lapse cell viability imaging for a period of 12h. Both tension and injury were required to induce cell death and cell movement in the formation of the acellular zone. DNA fragmentation studies and transmission electron microscopy indicated that cells necrosed. Parallel in vivo studies showed that cell-to-cell contacts were disrupted following grasping by the suture in tensioned tendon. Without tension, cell death was lessened and cell-to-cell contacts remained intact. Quantitative immunohistochemistry and 3D cellular profile mapping of wound healing markers over a one year time course showed that acellular zones arise rapidly and showed no evidence of healing whilst the wound healing response occurred in the surrounding tissues. The acellular zones were also evident in a standard modified "Kessler" clinical repair. In conclusion, the suture repair of injured tendons produces acellular zones, which may potentially cause early tendon failure. PMID:20600895

  9. Comparison of Lower Body Specific Resistance Training on the Hamstring to Quadriceps Strength Ratios in Men and Women

    ERIC Educational Resources Information Center

    Dorgo, Sandor; Edupuganti, Pradeep; Smith, Darla R.; Ortiz, Melchor

    2012-01-01

    In this study, we compared hamstring (H) and quadriceps (Q) strength changes in men and women, as well as changes in conventional and functional H:Q ratios following an identical 12-week resistance training program. An isokinetic dynamometer was used to assess 14 male and 14 female participants before and after the intervention, and conventional…

  10. Lack of Correlation between Dynamic Balance and Hamstring-to-Quadriceps Ratio in Patients with Chronic Anterior Cruciate Ligament Tears

    PubMed Central

    Lee, Jin-Hyuck; Jeong, Hye-Jin; Lee, Seok-Joo

    2015-01-01

    Purpose The purpose of this study was to evaluate the quadriceps and hamstring muscle strength and hamstring-to-quadriceps (HQ) ratio, as well as the relationships of these parameters with dynamic balance, in patients with anterior cruciate ligament (ACL) rupture. Materials and Methods We compared 25 patients diagnosed with chronic unilateral ACL tears and 25 age-matched healthy volunteers. The maximal torque of the quadriceps and hamstring and dynamic balance were measured. Results Although the isokinetic maximal peak torques were about 50% lower in the quadriceps (57%, p<0.001) and hamstring (56%, p=0.001) muscles in the chronic ACL tear group than in the control group, their HQ ratios were similar (56%±17% vs. 58%±6%, p=0.591). HQ ratio was significantly correlated with anterior-posterior stability index (r=-0.511, p=0.021) and overall stability index (r=-0.476, p=0.034) in control group, but these correlations were not observed in chronic ACL tear group. Conclusions Thigh muscle strength was about 50% lower in the chronic ACL tear group than in the control group, but the HQ ratio was similar. The dynamic balance of the knee was not influenced by thigh muscle strength but was influenced by HQ ratio in healthy young individuals. However, HQ ratio was not correlated with dynamic knee balance in chronic ACL tear patients. PMID:26060609

  11. Stability training of the lumbo-pelvo-hip complex influence stiffness of the hamstrings: a preliminary study.

    PubMed

    Kuszewski, M; Gnat, R; Saulicz, E

    2009-04-01

    An analysis of data obtained in an experiment investigating the influence of stability training of the lumbo-pelvo-hip complex (LPHC) on stiffness of the hamstrings is presented. Randomized controlled trial. The study included 30 subjects (aged 18-42 years) with increased stiffness of the hamstrings at baseline. Over a period of 4 weeks, stability training aiming to activate the deep stabilizing muscle subsystem and to integrate its action with the superficial subsystem was introduced in the experimental group. The control group remained unaffected. Three series of measurements were applied (baseline, after 2 weeks, and after 4 weeks). A digital inclinometer was used to measure outcomes of passive knee extension in the supine test. In the experimental group, a tendency to decrease stiffness of the hamstrings was observed. It was the opposite in the control group. Significant intra-group differences in the experimental group between series 1 and 3 measurements for both the right and left lower extremities were revealed. Stability training of the LPHC showed a tendency to be effective in reducing stiffness of the hamstrings. PMID:18384489

  12. Recurrence of cystic adventitial disease in an interposed vein graft.

    PubMed

    Ohta, T; Kato, R; Sugimoto, I; Kondo, M; Tsuchioka, H

    1994-09-01

    A case of cystic adventitial disease (CAD) of the popliteal artery with intermittent claudication in the left calf is reported. This patient was first treated by total excision of the cyst and the involved artery followed by graft interposition with an autogenous saphenous vein. Recurrence of CAD in the interposed vein graft was noted after 6 months, and excision of the cyst with the involved graft and graft interposition with an autogenous saphenous vein was again required. We consider that the definitive evidence from early recurrence in the interposed vein graft shown in this case will close the discussion of the cause of CAD. The cystic lesion is thought by some to originate from the adventitia; traumatic, embryologic, or systemic abnormality theories were proposed. We assume that the mucin-secreting synovial cells originating from the neighboring joint capsule, tendon sheath, or, in some cases, from the ganglion itself, directly invade the adventitia through any rough or injured crack caused by trauma to the adventitia or simply attach to and encircle the adventitia. Total resection of the lesion with grafting is the recommended treatment for CAD because of the excellent results. However, as shown in our case, complete removal of the synovial cells even by resection technique may be difficult; therefore intensive follow-up is fundamentally necessary in this disease. PMID:8079189

  13. [Tissue grafts: an activity concerning many patients].

    PubMed

    Loty, B

    1997-11-15

    Tissue allografts mainly include corneas, bone (and cartilage, tendon, ligament, aponevrosis), skin, vessels and cardiac valves. All these grafts have been widely used for many years and were the subject of a large number of experimental and clinical studies. The different steps allowing the obtention of different tissue allografts have in fact a common organization through tissue procurement and banking activities. Tissue banks have a central situation ensuring security, safety, traceability and distribution of tissues. Appropriate organization of the banks, and respect of high level standards are thus mandatory. Tissue transplantation activity in France has been studied through national surveys: they concern more than 600 hospitals and clinics, and grafts procured in France (excluding imported allografts) are around 15,000 a year. Precise regulation implied by the bioethical law published in 1994 and homogeneous organization of the activity allow the use of stringent and regularly updated standards, allowing the distribution to the patients of safe grafts procured in ethical conditions. The actual shortage of tissue allografts in France implies increasing procurement through a better organization of retrieval in hospitals and clinics and donation promotion. PMID:9501596

  14. Treatment of Large Recurrent Bilateral Xanthomatosis of Achilles Tendon- A Case Report

    PubMed Central

    Senthil, L.; Jambu, N.; Chittaranjan, Samuel

    2015-01-01

    Introduction: Xanthomas of the Achilles tendon are a rare interesting orthopaedic condition. There are very few articles dealing with the treatment of recurrent xanthomatosis of tendoachilles. Here we report this patient with bilateral recurrent xanthomatosis of tendoachilles. Case Report: A 37 year old male patient presented with multiple lesions in the body with bilateral swelling in the tendoachilles. The swelling was excised before three years elsewhere and there was recurrence of the lesion after 6 months subsequently. There was ulceration on the right side. The patient was treated by total resection of the lesion and reconstruction using tensorfascialata graft. Conclusion: Complete excision of the lesion is needed to reduce recurrence. Reconstruction of the defect is a challenge due to the large defect. Tensorfascialata graft results in good functional outcome of the patient even in large defects.

  15. Shear Load Transfer in High and Low Stress Tendons

    PubMed Central

    Kondratko-Mittnacht, Jaclyn; Duenwald-Kuehl, Sarah; Lakes, Roderic; Vanderby, Ray

    2016-01-01

    Background Tendon is an integral part of joint movement and stability, as it functions to transmit load from muscle to bone. It has an anisotropic, fibrous hierarchical structure that is generally loaded in the direction of its fibers/fascicles. Internal load distributions are altered when joint motion rotates an insertion site or when local damage disrupts fibers/fascicles, potentially causing inter-fiber (or inter-fascicular) shear. Tendons with different microstructure (helical versus linear) may redistribute loads differently. Method of Approach This study explored how shear redistributes axial loads in rat tail tendon (low stress tendons with linear microstructure) and porcine flexor tendon (high stress with helical microstructure) by creating lacerations on opposite sides of the tendon, ranging from about 20-60% of the tendon width, to create various magnitudes of shear. Differences in fascicular orientation were quantified using polarized light microscopy. Results and Conclusions Unexpectedly, both tendon types maintained about 20% of pre-laceration stress values after overlapping cuts of 60% of tendon width (no intact fibers end to end) suggesting that shear stress transfer can contribute more to overall tendon strength and stiffness than previously reported. All structural parameters for both tendon types decreased linearly with increasing laceration depth. The tail tendon had a more rapid decline in post-laceration elastic stress and modulus parameters as well as a more linear and less tightly packed fascicular structure, suggesting that positional tendons may be less well suited to redistribute loads via a shear mechanism. PMID:25700261

  16. Platelet-Rich Plasma in Addition to Rehabilitation for Acute Hamstring Injuries in NFL Players

    PubMed Central

    Rettig, Arthur C.; Meyer, Susan; Bhadra, Arup K.

    2013-01-01

    Background: Platelet-rich plasma (PRP) injections have been proposed to hasten soft tissue healing. There is a lack of evidence in the current literature to support their efficacy in elite athletes. Purpose: To investigate the effects of the addition of PRP to rehabilitation in the treatment of acute hamstring injuries in professional National Football League (NFL) players and to report the time to return to play. Study Design: Case control study. Methods: Ten NFL players with similar hamstring injury patterns were retrospectively divided into 2 groups. The treatment group (PRP; n = 5) was injected with PRP and the control group (non-PRP; n = 5) was not injected; both groups completed a rehabilitation program. The PRP injections were administered under ultrasound guidance with precise localization of the injury site, within 24 to 48 hours of injury. Age, muscle involved, extent of injury, grading, and time to return to play were noted. Descriptive statistics and the exact Wilcoxon rank-sum test were used for data analysis. Results: The mean age was 23 years (range, 22-27 years) for the PRP group and 26 years (range, 22-28 years) for the non-PRP group (P = .42). The median longitudinal extent of the injury was 14 cm (range, 9-18 cm) in the PRP group and 15 cm (range, 9-16 cm) in the non-PRP group (P = .77). The average transverse extent of the injury in the PRP and non-PRP groups was 4 cm (range, 1.6-6 cm) and 3.5 cm (range, 2-5 cm), respectively, and the respective average anteroposterior extent was 4 cm (range, 1.9-5 cm) and 2.9 cm (range, 1.5-4 cm). The long head of biceps femoris was most commonly involved (4 in each group), with a single tear of the semimembranosus in each group. The median injury classification was grade 2 in both groups. The median time to return to play was 20 days (range,16-30 days) in the PRP group and 17 days (range, 8-81 days) in the non-PRP group (P = .73). Conclusion: There were no significant differences in recovery from hamstring

  17. The relationship of vascularity and water content to tensile strength in a patellar tendon replacement of the anterior cruciate in dogs.

    PubMed

    McFarland, E G; Morrey, B F; An, K N; Wood, M B

    1986-01-01

    The methods and materials for ACL reconstruction are important issues for the practicing orthopaedic surgeon. In this study a model was developed to study the biological and biomechanical characteristics of a patellar tendon autograft used for ACL reconstruction. Specifically it was hypothesized that since vascularity of these grafts reflects their "healthiness," strength and vascularity should be inversely related in the early period after implantation. Using an over the top technique, a patellar tendon graft was placed in three groups of dogs and studied at 37, 57, and 120 days. Vascularity of the grafts was measured using technetium-tagged red blood cells, and percent water by weight was determined by dessication. Tensile testing to failure was performed using an MTS machine. The grafts became more vascular, more hydrated, less stiff, and less strong (by 4 weeks) than controls. By 16 weeks the vascular response was subsiding but the grafts remained only 40% as strong as controls. Percent water increased significantly over controls for all time periods. Decrease in strength correlated poorly with vascularity but correlated well with increase in percent water. These findings suggest that the change in strength of an intraarticular ACL replacement relates more to a basic rearrangement of its collagen-ground substance relationships, and that vascularity may reflect the inflammatory response bringing about these changes. The model developed in this study serves as a basis for further studies, and the findings reveal important information about the behavior of ACL grafting materials. PMID:3541655

  18. Biomechanical comparison of expanded polytetrafluoroethylene (ePTFE) and PTFE interpositional patches and direct tendon-to-bone repair for massive rotator cuff tears in an ovine model

    PubMed Central

    McKeown, Andrew DJ; Beattie, Rebekah F; Murrell, George AC

    2015-01-01

    Background Massive irreparable rotator cuff tears are a difficult problem. Modalities such as irrigation and debridement, partial repair, tendon transfer and grafts have been utilized with high failure rates and mixed results. Synthetic interpositional patch repairs are a novel and increasingly used approach. The present study aimed to examine the biomechanical properties of common synthetic materials for interpositional repairs in contrast to native tendon. Methods Six ovine tendons, six polytetrafluoroethylene (PTFE) felt sections and six expanded PTFE (ePTFE) patch sections were pulled-to-failure to analyze their biomechanical and material properties. Six direct tendon-to-bone surgical method repairs, six interpositional PTFE felt patch repairs and six interpositional ePTFE patch repairs were also constructed in ovine shoulders and pulled-to-failure to examine the biomechanical properties of each repair construct. Results Ovine tendon had higher load-to-failure (591 N) and had greater stiffness (108 N/mm) than either PTFE felt (296 N, 28 N/mm) or ePTFE patch sections (323 N, 34 N/mm). Both PTFE felt and ePTFE repair techniques required greater load-to-failure (225 N and 177 N, respectively) than direct tendon-to-bone surgical repairs (147 N) in ovine models. Conclusions Synthetic materials lacked several biomechanical properties, including strength and stiffness, compared to ovine tendon. Interpositional surgical repair models with these materials were significantly stronger than direct tendon-to-bone model repairs. PMID:27582997

  19. Bone grafts in dentistry

    PubMed Central

    Kumar, Prasanna; Vinitha, Belliappa; Fathima, Ghousia

    2013-01-01

    Bone grafts are used as a filler and scaffold to facilitate bone formation and promote wound healing. These grafts are bioresorbable and have no antigen-antibody reaction. These bone grafts act as a mineral reservoir which induces new bone formation. PMID:23946565

  20. Biomechanical Comparison Between Bashti Bone Plug Technique and Biodegradable Screw for Fixation of Grafts in Ligament surgery

    PubMed Central

    Bashti, Kaveh; Tahmasebi, Mohammad N; Kaseb, Hasan; Farahmand, Farzam; Akbar, Mohammad; Mobini, Amir

    2015-01-01

    Background: Ligament reconstruction is a common procedure in orthopedic surgery. Although several popular techniques are currently in use, new methods are proposed for secure fixation of the tendon graft into the bone tunnel. Purposes: We sought to introduce our new technique of Bashti bone plug for fixation of soft tissue graft in anterior cruciate ligament (ACL) reconstruction and to compare its biomechanical features with conventional absorbable interference screw technique in a bovine model. Methods: Twenty pairs of bovine knees were harvested after death. Soft tissue was removed and the Achilles tendon was harvested to be used as an ACL graft. It was secured into the bone tunnel on the tibial side via two different methods: Bashti Bone Plug technique and conventional screw method. Biomechanical strength was measured using 200 N and 300 N cyclic loading on the graft. Pull out strength was also tested until the graft fails. Results: No graft failure was observed after 200 N and 300 N cyclic loading in either fixation methods. When testing for pull out failure, 21 tendons (53%) were torn and 19 tendons (48%) slipped out. No fixation failure occurred, which did not reveal a significant difference between the bone plug or interference screw group (P=0.11). The mean pull out force until failure of the graft was 496±66 N in the screw group and 503±67 N in the bone plug group (P=0.76). Conclusions: Our suggested fixation technique of Bashti bone plug is a native, cheap, and feasible method that provides comparable biomechanical strength with interference screw when soft tissue fixation was attempted in bovine model. PMID:25692166

  1. Following rotator cuff tears, the remaining (intact) tendons are mechanically altered

    PubMed Central

    Perry, Stephanie M.; Getz, Charles L.; Soslowsky, Louis J.

    2009-01-01

    Although presumed, damage in the remaining (intact) rotator cuff tendons in the presence of an isolated supraspinatus tendon tear or multiple tendon tear has not been well studied. This study utilized an animal model of multiple rotator cuff tendon tears to investigate alterations in the remaining (intact) tendon mechanical properties at 4 and 8 weeks post-injury. Twenty-four animals served as uninjured controls, while seventy-two were divided among the tendon detachment groups (supraspinatus tendon detachment, supraspinatus+infraspinatus tendon detachment, supraspinatus+subscapularis tendon detachment). We found the remaining (intact) rotator cuff tendons have decreased mechanical properties in the presence of rotator cuff tears. Remaining (intact) subscapularis and infraspinatus tendon cross-sectional area increased, while tendon modulus decreased after both one and two tendon tears. Additionally, the remaining (intact) tendon cross-sectional areas continued to increase with time post-injury. These alterations could potentially lead to further tendon damage and tear progression. PMID:19095175

  2. Monitoring tissue formation and organization of engineered tendon by optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Bagnaninchi, P. O.; Yang, Y.; Maffulli, N.; Wang, R. K.; El Haj, A.

    2006-02-01

    The uniaxial orientation and bundle formation of collagen fibres determine the mechanical properties of tendons. Thus the particular challenge of tendon tissue engineering is to build the tissue with a highly organized structure of collagen fibres. Ultimately the engineered construct will be used as autologous grafts in tendon surgery, withstanding physiological loading. We grew pig tenocytes in porous chitosan scaffolds with multiple microchannels of 250-500 μm. The cell proliferation and production of extra-cellular matrix (ECM) within the scaffolds have been successfully monitored by Optical Coherence Tomography (OCT), a bench-top OCT system equipped with a broadband light source centred at 1300 nm. Under sterile condition, the measurements were performed on-line and in a non-destructive manner. In addition, a novel method based on OCT imaging, which calculates the occupation ratio of the microchannel derived from the scattered intensity has been developed. It is confirmed that the occupation ratio is correlated to cell proliferation and ECM production in the scaffolds. Thus this method has been utilised to assess the effect of different culture conditions on the tissue formation. The use of a perfusion bioreactor has resulted in a significantly (p<1e -3) higher cell proliferation and matrix production.

  3. Achilles tendon disorders in runners--a review.

    PubMed

    Smart, G W; Taunton, J E; Clement, D B

    1980-01-01

    The Achilles tendon and the classification, etiology, diagnosis, treatment, and management of Achilles tendon disorders in runners are reviewed. Due to the presence of a paratenon sheath, the classification of Achilles tendon disease should be revised. Several etiological mechanisms have been proposed in Achilles tendon disease. The authors recognize: faulty foot biomechanics; poor lower leg flexibility; poorly designed athletic footwear; training surfaces; training intensity; overuse through excessive mileage; inactivity; local steroid injections; rheumatic conditions; and indirect violence. An accurate, thorough differential diagnosis is essential when the athlete presents with an Achilles tendon disorder. Except in total rupture and in extensive partial rupture, the authors do not recommend cast immobilization in the treatment of Achilles tendon disease. When the athlete presents with total rupture of the Achilles tendon, the authors believe that surgical repair is the treatment method of choice. Rehabilitation programs to follow successful treatment of Achilles tendon disease are also presented. PMID:6999281

  4. Nutritional research may be useful in treating tendon injuries.

    PubMed

    Curtis, Luke

    2016-06-01

    Tendon injures cause a great deal of disability and pain, and increase medical costs. However, relatively little is known about tendon biology and healing. Many tendon-related surgical procedures are not very successful and leave the patient with essentially a chronic injury. New therapeutic approaches for tendon injury are needed. Preliminary evidence suggests that various nutrients such as proteins, amino acids (leucine, arginine, glutamine), vitamins C and D, manganese, copper, zinc, and phytochemicals may be useful in improving tendon growth and healing. More research on nutrition and tendon health is needed. Because many nutrients are required for tendon health, nutritional interventions involving multiple nutrients may be more effective than single-nutrient strategies. In the future, ideal treatment regimens for tendon injuries may include a multifaceted "bundle" of nutrition, drugs, biologic products, extracellular matrix therapies, exercise/physical therapy, and possibly surgery. PMID:26921066

  5. Robot Arm with Tendon Connector Plate and Linear Actuator

    NASA Technical Reports Server (NTRS)

    Ihrke, Chris A. (Inventor); Diftler, Myron A. (Inventor); Bridgwater, Lyndon (Inventor); Nguyen, Vienny (Inventor); Millerman, Alexander (Inventor)

    2014-01-01

    A robotic system includes a tendon-driven end effector, a linear actuator, a flexible tendon, and a plate assembly. The linear actuator assembly has a servo motor and a drive mechanism, the latter of which translates linearly with respect to a drive axis of the servo motor in response to output torque from the servo motor. The tendon connects to the end effector and drive mechanism. The plate assembly is disposed between the linear actuator assembly and the tendon-driven end effector and includes first and second plates. The first plate has a first side that defines a boss with a center opening. The second plate defines an accurate through-slot having tendon guide channels. The first plate defines a through passage for the tendon between the center opening and a second side of the first plate. A looped end of the flexible tendon is received within the tendon guide channels.

  6. Modelling approaches for evaluating multiscale tendon mechanics.

    PubMed

    Fang, Fei; Lake, Spencer P

    2016-02-01

    Tendon exhibits anisotropic, inhomogeneous and viscoelastic mechanical properties that are determined by its complicated hierarchical structure and varying amounts/organization of different tissue constituents. Although extensive research has been conducted to use modelling approaches to interpret tendon structure-function relationships in combination with experimental data, many issues remain unclear (i.e. the role of minor components such as decorin, aggrecan and elastin), and the integration of mechanical analysis across different length scales has not been well applied to explore stress or strain transfer from macro- to microscale. This review outlines mathematical and computational models that have been used to understand tendon mechanics at different scales of the hierarchical organization. Model representations at the molecular, fibril and tissue levels are discussed, including formulations that follow phenomenological and microstructural approaches (which include evaluations of crimp, helical structure and the interaction between collagen fibrils and proteoglycans). Multiscale modelling approaches incorporating tendon features are suggested to be an advantageous methodology to understand further the physiological mechanical response of tendon and corresponding adaptation of properties owing to unique in vivo loading environments. PMID:26855747

  7. No Telescoping Effect with Dual Tendon Vibration

    PubMed Central

    Bellan, Valeria; Wallwork, Sarah B.; Stanton, Tasha R.; Reverberi, Carlo; Gallace, Alberto; Moseley, G. Lorimer

    2016-01-01

    The tendon vibration illusion has been extensively used to manipulate the perceived position of one’s own body part. However, findings from previous research do not seem conclusive sregarding the perceptual effect of the concurrent stimulation of both agonist and antagonist tendons over one joint. On the basis of recent data, it has been suggested that this paired stimulation generates an inconsistent signal about the limb position, which leads to a perceived shrinkage of the limb. However, this interesting effect has never been replicated. The aim of the present study was to clarify the effect of a simultaneous and equal vibration of the biceps and triceps tendons on the perceived location of the hand. Experiment 1 replicated and extended the previous findings. We compared a dual tendon stimulation condition with single tendon stimulation conditions and with a control condition (no vibration) on both ‘upward-downward’ and ‘towards-away from the elbow’ planes. Our results show a mislocalisation towards the elbow of the position of the vibrated arm during dual vibration, in line with previous results; however, this did not clarify whether the effect was due to arm representation contraction (i.e., a ‘telescoping’ effect). Therefore, in Experiment 2 we investigated explicitly and implicitly the perceived arm length during the same conditions. Our results clearly suggest that in all the vibration conditions there was a mislocalisation of the entire arm (including the elbow), but no evidence of a contraction of the perceived arm length. PMID:27305112

  8. The Influence of Prior Hamstring Injury on Lengthening Muscle Tissue Mechanics

    PubMed Central

    Silder, Amy; Reeder, Scott B.; Thelen, Darryl G.

    2010-01-01

    Hamstring strain injuries often occur near the proximal musculotendon junction (MTJ) of the biceps femoris. Post-injury remodeling can involve scar tissue formation, which may alter contraction mechanics and influence re-injury risk. The purpose of this study was to assess the affect of prior hamstring strain injury on muscle tissue displacements and strains during active lengthening contractions. Eleven healthy and eight subjects with prior biceps femoris injuries were tested. All previously injured subjects had since returned to sport and exhibited evidence of residual scarring along the proximal aponeurosis. Subjects performed cyclic knee flexion-extension on an MRI-compatible device using elastic and inertial loads, which induced active shortening and lengthening contractions, respectively. CINE phase-contrast imaging was used to measure tissue velocities within the biceps femoris during these tasks. Numerical integration of the velocity information was used to estimate two-dimensional tissue displacement and strain fields during muscle lengthening. The largest tissue motion was observed along the distal MTJ, with the active lengthening muscle exhibiting significantly greater and more homogeneous tissue displacements. First principal strains magnitudes were largest along the proximal MTJ for both loading conditions. The previously injured subjects exhibited less tissue motion and significantly greater strains near the proximal MTJ. We conclude that localized regions of high tissue strains during active lengthening contractions may predispose the proximal biceps femoris to injury. Furthermore, post-injury remodeling may alter the in-series stiffness seen by muscle tissue and contribute to the relatively larger localized tissue strains near the proximal MTJ, as was observed in this study. PMID:20472238

  9. Knee Extension Strength and Hamstrings-to-Quadriceps Imbalances in Elite Soccer Players.

    PubMed

    Bogdanis, G C; Kalapotharakos, V I

    2016-02-01

    This study examined the relationship between hamstrings-to-quadriceps strength ratio (H:Q) and relative strength of the knee extensors in elite soccer players. Peak torque was measured during isokinetic knee extension/flexion at angular velocities of 60°·s(-1), 180°·s(-1) and 300°·s(-1). 18 professional players were divided into 2 groups, depending on their H:Q at 60°·s(-1). Players in the lower H:Q group (n=7) had significantly smaller H:Q ratios compared with the higher H:Q group (n=11) at all angular velocities (60°·s(-1): 49.2%; 95% CI: 61.3-57.8% vs. 59.5%; 95% CI: 52.2-46.2%, p=0.001). Players in the lower H:Q group had greater knee-extension peak torque compared with the higher H:Q group (60°·s(-1): 313; 95% CI: 335-291 vs. 269; 95% CI: 289-250 N·m, p=0.01). No differences were found in hamstrings' strength between the 2 groups (60°·s(-1): 156; 95% CI: 170-143 vs. 160; 95% CI: 173-148 N·m, p=0.96). Negative correlations between knee extension peak torque and H:Q ratio were observed at all angular velocities (r=-0.65 to -0.67, p<0.01). In conclusion, a low H:Q strength ratio measured during isokinetic strength testing in professional soccer players, is observed mainly in those with strong quadriceps muscles, while players with lower quadriceps strength have H:Q ratios around the recommended values. PMID:26509377

  10. Vascular changes in the ruptured Achilles tendon and paratenon.

    PubMed

    Kvist, M; Józsa, L; Järvinen, M

    1992-01-01

    Thirty patients with ruptures of the Achilles tendon were studied. There were 21 men and 9 women with an average age of 36 years. Specimens from the tendon and paratenon in 24 were examined histologically. Tissue samples of 20 were studied by electron microscopy. Marked degenerative, obliterative and/or inflammatory vascular changes were found in all the ruptured tendons and their paratenon. Our findings indicate that poor vascularity play a role in the aetiology of rupture of the Achilles tendon. PMID:1473893

  11. p38 MAPK Signaling in Postnatal Tendon Growth and Remodeling

    PubMed Central

    Schwartz, Andrew J.; Sarver, Dylan C.; Sugg, Kristoffer B.; Dzierzawski, Justin T.; Gumucio, Jonathan P.; Mendias, Christopher L.

    2015-01-01

    Tendon is a dynamic tissue whose structure and function is influenced by mechanical loading, but little is known about the fundamental mechanisms that regulate tendon growth and remodeling in vivo. Data from cultured tendon fibroblasts indicated that the p38 MAPK pathway plays an important role in tendon fibroblast proliferation and collagen synthesis in vitro. To gain greater insight into the mechanisms of tendon growth, and explore the role of p38 MAPK signaling in this process, we tested the hypotheses that inducing plantaris tendon growth through the ablation of the synergist Achilles tendon would result in rapid expansion of a neotendon matrix surrounding the original tendon, and that treatment with the p38 MAPK inhibitor SB203580 would prevent this growth. Rats were treated with vehicle or SB203580, and subjected to synergist ablation by bilateral tenectomy of the Achilles tendon. Changes in histological and biochemical properties of plantaris tendons were analyzed 3, 7, or 28 days after overload, and comparisons were made to non-overloaded animals. By 28 days after overload, tendon mass had increased by 30% compared to non-overloaded samples, and cross-sectional area (CSA) increased by around 50%, with most of the change occurring in the neotendon. The expansion in CSA initially occurred through the synthesis of a hyaluronic acid rich matrix that was progressively replaced with mature collagen. Pericytes were present in areas of active tendon growth, but never in the original tendon ECM. Inhibition of p38 MAPK resulted in a profound decrease in IL6 expression, and had a modest effect on the expression of other ECM and cell proliferation genes, but had a negligible impact on overall tendon growth. The combined results from this study provided novel insights into tendon mechanobiology, and suggest that p38 MAPK signaling does not appear to be necessary for tendon growth in vivo. PMID:25768932

  12. Tendon neuroplastic training: changing the way we think about tendon rehabilitation: a narrative review

    PubMed Central

    Rio, Ebonie; Kidgell, Dawson; Moseley, G Lorimer; Docking, Sean; Purdam, Craig; Cook, Jill

    2016-01-01

    Tendinopathy can be resistant to treatment and often recurs, implying that current treatment approaches are suboptimal. Rehabilitation programmes that have been successful in terms of pain reduction and return to sport outcomes usually include strength training. Muscle activation can induce analgesia, improving self-efficacy associated with reducing one's own pain. Furthermore, strength training is beneficial for tendon matrix structure, muscle properties and limb biomechanics. However, current tendon rehabilitation may not adequately address the corticospinal control of the muscle, which may result in altered control of muscle recruitment and the consequent tendon load, and this may contribute to recalcitrance or symptom recurrence. Outcomes of interest include the effect of strength training on tendon pain, corticospinal excitability and short interval cortical inhibition. The aims of this concept paper are to: (1) review what is known about changes to the primary motor cortex and motor control in tendinopathy, (2) identify the parameters shown to induce neuroplasticity in strength training and (3) align these principles with tendon rehabilitation loading protocols to introduce a combination approach termed as tendon neuroplastic training. Strength training is a powerful modulator of the central nervous system. In particular, corticospinal inputs are essential for motor unit recruitment and activation; however, specific strength training parameters are important for neuroplasticity. Strength training that is externally paced and akin to a skilled movement task has been shown to not only reduce tendon pain, but modulate excitatory and inhibitory control of the muscle and therefore, potentially tendon load. An improved understanding of the methods that maximise the opportunity for neuroplasticity may be an important progression in how we prescribe exercise-based rehabilitation in tendinopathy for pain modulation and potentially restoration of the corticospinal

  13. Recurrent Dislocation of The Extensor Carpi Ulnaris Tendon in a Water-Polo Athlete

    PubMed Central

    Stathopoulos, Ioannis P.; Raptis, Konstantinos; Ballas, Efstathios G.; Spyridonos, Sarantis-Petros G.

    2016-01-01

    Introduction: Dislocation/subluxation of the Extensor Carpi Ulnaris (ECU) tendon is a rare condition in the general population, but is a common problem among athletes that subject their wrists to forceful rotational movements. Pain and snapping sensation at the dorsoulnar aspect of the wrist especially during supination are the predominant symptoms that often necessitate surgical intervention. Case Presentation: We present a case of a professional water-polo athlete with recurrent ECU tendon dislocation, in whom a combination of direct repair of the tendon’s subsheath and reinforcement with an extensor retinaculum graft led to definitive resolution of her symptoms and resulted in her uneventful return to high-level sport activities 4 months postoperatively. Conclusions: The treatment of symptomatic ECU instability is still controversial, especially for acute dislocations. Depending on the type of injury many surgical techniques have been proposed. Combination of direct repair of the tendon’s subsheath and reinforcement with an extensor retinaculum graft is a reliable option. PMID:27218041

  14. 21 CFR 888.3025 - Passive tendon prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) Identification. A passive tendon prosthesis is a device intended to be implanted made of silicon elastomer or a... flexor tendon of the hand. The device is implanted for a period of 2 to 6 months to aid growth of a new tendon sheath. The device is not intended as a permanent implant nor to function as a replacement for...

  15. 21 CFR 888.3025 - Passive tendon prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) Identification. A passive tendon prosthesis is a device intended to be implanted made of silicon elastomer or a... flexor tendon of the hand. The device is implanted for a period of 2 to 6 months to aid growth of a new tendon sheath. The device is not intended as a permanent implant nor to function as a replacement for...

  16. 21 CFR 888.3025 - Passive tendon prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) Identification. A passive tendon prosthesis is a device intended to be implanted made of silicon elastomer or a... flexor tendon of the hand. The device is implanted for a period of 2 to 6 months to aid growth of a new tendon sheath. The device is not intended as a permanent implant nor to function as a replacement for...

  17. 21 CFR 888.3025 - Passive tendon prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) Identification. A passive tendon prosthesis is a device intended to be implanted made of silicon elastomer or a... flexor tendon of the hand. The device is implanted for a period of 2 to 6 months to aid growth of a new tendon sheath. The device is not intended as a permanent implant nor to function as a replacement for...

  18. 21 CFR 888.3025 - Passive tendon prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Passive tendon prosthesis. 888.3025 Section 888...) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3025 Passive tendon prosthesis. (a) Identification. A passive tendon prosthesis is a device intended to be implanted made of silicon elastomer or...

  19. Effect of pulley excision on flexor tendon biomechanics.

    PubMed

    Peterson, W W; Manske, P R; Bollinger, B A; Lesker, P A; McCarthy, J A

    1986-01-01

    Flexor tendon function following excision of various portions of the fibro-osseous pulley system was measured biomechanically using a tensile testing machine. The biomechanical parameters measured were tendon excursion (the excursion of the tendon required to fully flex the digit) and work of flexion (the area under the force-excursion curve, representing all the forces that resist tendon flexion). In this experiment, work of flexion included the forces necessary to accomplish full digital flexion against a 15-g counter-weight, as well as the frictional forces that resist tendon gliding. The results indicate that the work of flexion was affected to a greater degree by pulley loss than was tendon excursion, suggesting that it is a more sensitive measurement of tendon function. A2 was found to be the single most important pulley for flexor tendon function, followed by A4. However, both A2 and A4 had to be present if near-normal hand function was to be achieved; sacrificing the A1 pulley was not associated with a significant loss of flexion. The "pulley effect" of the skin and soft tissue as a supplement to the fibro-osseous pulleys in reducing tendon bow-stringing was also noted. Although the parameters of tendon excursion and work of flexion were used in this study to determine the effect of pulley loss on tendon function, they can also be used to evaluate other flexor tendon studies, such as pulley reconstruction. PMID:3950813

  20. Acute effects of static stretching on peak and end-range hamstring-to-quadriceps functional ratios

    PubMed Central

    Sekir, Ufuk; Arabaci, Ramiz; Akova, Bedrettin

    2015-01-01

    AIM: To evaluate if static stretching influences peak and end-range functional hamstring-to-quadriceps (H/Q) strength ratios in elite women athletes. METHODS: Eleven healthy female athletes in an elite competitive level participated to the study. All the participants fulfilled the static stretching or non-stretching (control) intervention protocol in a randomized design on different days. Two static unassisted stretching exercises, one in standing and one in sitting position, were used to stretch both the hamstring and quadriceps muscles during these protocols. The total time for the static stretching was 6 ± 1 min. The isokinetic peak torque measurements for the hamstring and quadriceps muscles in eccentric and concentric modes and the calculations for the functional H/Q strength ratios at angular velocities of 60°/s and 180°/s were made before (pre) and after (post) the control or stretching intervention. The strength measurements and functional strength ratio calculations were based during the entire- and end-range of knee extension. RESULTS: The pre-test scores for quadriceps and hamstring peak torque and end range values were not significantly different between the groups (P > 0.05). Subsequently, although the control group did not exhibit significant changes in quadriceps and hamstring muscle strength (P > 0.05), static stretching decreased eccentric and concentric quadriceps muscle strength at both the 60°/s and 180°/s test speeds (P < 0.01). Similarly, static stretching also decreased eccentric and concentric hamstring muscle strength at both the 60°/s and 180°/s test speeds (P < 0.01). On the other hand, when the functional H/Q strength ratios were taken into consideration, the pre-intervention values were not significant different between the groups both during the entire and end range of knee extension (P > 0.05). Furthermore, the functional H/Q strength ratios exhibited no significant alterations during the entire and end ranges of knee extension

  1. Biodegradable synthetic scaffolds for tendon regeneration

    PubMed Central

    Reverchon, Ernesto; Baldino, Lucia; Cardea, Stefano; De Marco, Iolanda

    2012-01-01

    Summary Tissue regeneration is aimed at producing biological or synthetic scaffolds to be implanted in the body for regenerate functional tissues. Several techniques and materials have been used to obtain biodegradable synthetic scaffolds, on which adhesion, growth, migration and differentiation of human cells has been attempted. Scaffolds for tendon regeneration have been less frequently proposed, because they have a complex hierarchical structure and it is very difficult to mimic their peculiar mechanical properties. In this review, we critically analyzed the proposed materials and fabrication techniques for tendon tissue engineering and we indicated new preparation processes, based on the use of supercritical fluids, to produce scaffolds with characteristics very similar to the native tendon structure. PMID:23738295

  2. Ultrasonic properties of tendon: velocity, attenuation, and backscattering in equine digital flexor tendons.

    PubMed

    Miles, C A

    1996-05-01

    Ultrasound velocity, attenuation, and backscattering were measured in vitro in samples of equine digital flexor tendon sandwiched between plane, parallel rexolite buffer rods. The buffer rods were coupled to transmitting and receiving transducers (nominally 10 MHz) mounted in-line and facing one another on the jaws of a digital caliper. Six superficial digital flexor (SDF) tendons and six deep digital flexor (DDF) tendons were measured in three orthogonal directions: along the long axis of the tendon (D), and across the tendon in the dorsal-volar (C), and lateral (L) directions. Substantial anisotropy was apparent in all the measured properties. The velocity data, which in both tendons showed a higher velocity along the fibers than across (e.g., in the DDF tendon at 0 degrees C: 1713 +/- 9 m/s in the D direction compared with 1650 +/- 5 m/s in the C direction), were consistent with a composite comprising stiff fibers embedded in a less stiff medium of lower speed. The apparent backscattering coefficient adjusted for the tissue's frequency-dependent attenuation (e.g., in the C direction of the DDF tendon at 0 degrees C: 7.4 x 10(-3) cm-1 sr-1), was independent of frequency in both transverse directions and larger than that measured along the long axis of the tendon (e.g., in DDF tendon at 0 degrees C: 1.2 x 10(-3) cm-1 sr-1 at 7 MHz) in which direction the apparent backscattering coefficient increased with frequency as f4.0 +/- 1.2. The frequency-independent backscattering was thought to be due to specular reflection from the boundaries between the fascicles, i.e., the bundles of fibers making up the tendon, while backscattering along the axis was due to structures of unknown origin, but of a size much smaller than 45 microns. Attenuation of ultrasound directed along the fibers was higher than that across (at 7 MHz in DDF tendon at 0 degrees C: 58 dB/cm in the D direction compared with 11.3 dB/cm in the C direction). Calculations indicated that the attenuation was

  3. Tendon and ligament injuries: the genetic component

    PubMed Central

    September, Alison V; Schwellnus, Martin P; Collins, Malcolm

    2007-01-01

    Tendons and ligaments within the upper and lower limbs are some of the more common sites of musculoskeletal injuries during physical activity. Several extrinsic and intrinsic factors have been shown to be associated with these injuries. More recently, studies have suggested that there is also, at least in part, a genetic component to the Achilles tendon, rotator cuff and anterior cruciate ligament injuries. However, specific genes have not been suggested to be associated with rotator cuff or anterior cruciate ligament injuries. Sequence variants of the tenascin C (TNC) gene, on the other hand, have been shown to be associated with Achilles tendinopathies and Achilles tendon ruptures, whereas a variant of the collagen V α 1 (COL5A1) gene has also been shown to be associated with Achilles tendinopathies. Both genes encode for important structural components of tendons and ligaments. The COL5A1 gene encodes for a component of type V collagen, which has an important role in regulating collagen fibre assembly and fibre diameters. The TNC gene, on the other hand, encodes for TNC, which regulates the tissue's response to mechanical load. To date, only variants in two genes have been shown to be associated with Achilles tendon injuries. In addition, although specific genes have not been identified, investigators have suggested that there is also a genetic component to both rotator cuff and anterior cruciate ligament injuries. In future, specific genotypes associated with increased risk of injury to specific tendons and ligaments can prevent these injuries by identifying individuals at higher risk. PMID:17261551

  4. Mechanical Actuation Systems for the Phenotype Commitment of Stem Cell-Based Tendon and Ligament Tissue Substitutes.

    PubMed

    Govoni, Marco; Muscari, Claudio; Lovecchio, Joseph; Guarnieri, Carlo; Giordano, Emanuele

    2016-04-01

    High tensile forces transmitted by tendons and ligaments make them susceptible to tearing or complete rupture. The present standard reparative technique is the surgical implantation of auto- or allografts, which often undergo failure.Currently, different cell types and biomaterials are used to design tissue engineered substitutes. Mechanical stimulation driven by dedicated devices can precondition these constructs to a remarkable degree, mimicking the local in vivo environment. A large number of dynamic culture instruments have been developed and many appealing results collected. Of the cells that have been used, tendon stem cells are the most promising for a reliable stretch-induced tenogenesis, but their reduced availability represents a serious limitation to upscaled production. Biomaterials used for scaffold fabrication include both biological molecules and synthetic polymers, the latter being improved by nanotechnologies which reproduce the architecture of native tendons. In addition to cell type and scaffold material, other variables which must be defined in mechanostimulation protocols are the amplitude, frequency, duration and direction of the applied strain. The ideal conditions seem to be those producing intermittent tension rather than continuous loading. In any case, all physical parameters must be adapted to the specific response of the cells used and the tensile properties of the scaffold. Tendon/ligament grafts in animals usually have the advantage of mechanical preconditioning, especially when uniaxial cyclic forces are applied to cells engineered into natural or decellularized scaffolds. However, due to the scarcity of in vivo research, standard protocols still need to be defined for clinical applications. PMID:26661573

  5. [Comprehensive treatment in Achilles tendon rupture].

    PubMed

    Matus-Jiménez, Juan; Avalos, Cecilia Henríquez

    2007-01-01

    Due to incapacity caused by calcaneal tendon injuries for the reintegration of patients back to their daily activities and/or sparts it is necessary to decrease the time of reinstatement of patients. At present these times have improved by a good surgical technique and an early rehabilitation, and the patient is returned quickly as he sees less disability. It is proposed in this paper a type of surgical treatment and an early rehabilitation program, which have shortened the time of disability and incorporation to their daily activities and sports to eight weeks in 10 patients with Achilles tendon plasty. PMID:18159917

  6. [Isolated injury of the subscapular muscle tendon].

    PubMed

    Thielemann, F W; Kley, U; Holz, U

    1992-03-01

    Avulsion of the subscapularis tendon is caused by a combined abduction and external rotation trauma of the upper limb. Weakness of internal rotation and a positive apprehension test are clinical signs of the injury. A fracture of the lesser tuberosity in the x-ray film or a disruption of the subscapularis tendon documented in dynamic sonography of the shoulder clarify the diagnosis. Operative treatment is indicated of prevent weakness of internal rotation as well as anterior instability. This recommendation is supported by four cases with full range of motion and good anterior stability after surgery. PMID:1585252

  7. A new device for flexor tendon injuries.

    PubMed

    Dymarczyk, M

    2001-01-01

    Managing the treatment of patients with zone II flexor tendon injuries for successful outcomes has always been a challenge for the hand therapist. Working closely with the patient to help ensure follow-through with the protocol is frequently necessary. If a patient is compliant, the therapist's concern then becomes one of "scar wars" (to use a phrase coined by Ken Flowers). Early active range of motion and tendon gliding are critical parts of most programs. This author has developed a new idea in conjunction with the Indiana Hand Center protocol. PMID:11511017

  8. An unusual cause of Achilles tendon xanthoma.

    PubMed

    Parente, Fabienne; Vesnaver, Matthew; Massie, Rami; Baass, Alexis

    2016-01-01

    Tendinous xanthomas are often thought to be pathognomonic for familial hypercholesterolemia. In this report, we present the case of a young man with a normal lipid profile and Achilles tendon xanthoma. Biochemical and genetic studies confirmed the diagnosis of cerebrotendinous xanthomatosis in this patient. Cerebrotendinous xanthomatosis is a rare autosomal recessive disease associated with xanthoma in tendons and the brain as well as progressive neurologic deficits. Unfortunately, this rare form of reversible dementia is thought to be underdiagnosed. Early diagnosis and treatment of this disease with chenodeoxycholic acid is essential and has been shown to greatly improve the patient's symptoms and prognosis. PMID:27578138

  9. Spontaneous Achilles tendon rupture in alkaptonuria

    PubMed Central

    Alajoulin, Omar A.; Alsbou, Mohammed S.; Ja’afreh, Somayya O.; Kalbouneh, Heba M.

    2015-01-01

    Alkaptonuria (AKU) is a rare inborn metabolic disease characterized by accumulation of homogentisic acid (HGA). Excretion of HGA in urine causes darkening of urine and its deposition in connective tissues causes dark pigmentation (ochronosis), early degeneration of articular cartilage, weakening of the tendons, and subsequent rupture. In this case report, we present a rare case of a patient presented with unilateral spontaneous rupture of Achilles tendon due to AKU. The patient developed most of the orthopedic manifestations of the disease earlier than typical presentations. Alkaptonuria patients should avoid strenuous exercises and foot straining especially in patients developing early orthopedic manifestations. PMID:26620992

  10. Biomechanical Evaluation of Posterior Cruciate Ligament Reconstruction With Quadriceps Versus Achilles Tendon Bone Block Allograft

    PubMed Central

    Forsythe, Brian; Haro, Marc S.; Bogunovic, Ljiljana; Collins, Michael J.; Arns, Thomas A.; Trella, Katie J.; Shewman, Elizabeth F.; Verma, Nikhil N.; Bach, Bernard R.

    2016-01-01

    7 N/mm) groups. Conclusion: While the quadriceps trended to be a stronger construct with a greater maximum load and stiffness required during load to failure, only maximum force in comparison with the Achilles reached statistical significance. Quadriceps and Achilles tendon allografts had similar other biomechanical characteristics when used for a PCL reconstruction, but both were inferior to the native PCL. Clinical Relevance: The quadriceps tendon is a viable graft option in PCL reconstruction as it exhibits a greater maximum force and is otherwise comparable to the Achilles allograft. These findings expand allograft availability in PCL reconstruction. PMID:27570784

  11. Hand Rejuvenation: A Comprehensive Review of Fat Grafting.

    PubMed

    Hoang, Don; Orgel, Matthew I; Kulber, David A

    2016-05-01

    Dermal atrophy, bulging reticular veins, and prominent bones and tendons are characteristic of the aging hand. Demand for cosmetic procedures to restore a youthful appearance to the dorsum of the hand has risen in recent years. A review of the literature reveals that of the many options for hand restoration, autologous fat grafting stands out as the most promising choice compared with many available alternative options such as microdermabrasion, peeling agents, and dermal fillers. This article details the surgical technique and relevant anatomy necessary for successful hand rejuvenation. Future advancements may rely on further study into adipose-derived stem cells. PMID:27113709

  12. Efficacy of interference screw and double-docking methods using palmaris longus and GraftJacket for medial collateral ligament reconstruction of the elbow.

    PubMed

    Furukawa, Keizo; Pichora, Jamie; Steinmann, Scott; Faber, Kenneth J; Johnson, James A; King, Graham J W

    2007-01-01

    Single-strand elbow medial collateral ligament reconstruction strength was evaluated by use of double-docking and interference screw methods with either a palmaris longus tendon or GraftJacket as the reconstruction material. Thirteen upper extremities were mounted in 90 degrees of valgus orientation and subjected to cyclic valgus loading that increased progressively until failure occurred. The double-docking reconstructions outperformed the interference screw reconstructions (P < .05), whereas the palmaris longus and GraftJacket performed comparably (P > .05). The favorable initial strength of the GraftJacket make it a potentially viable alternative to the use of autogenous palmaris longus tendons; however, further studies are required to evaluate graft strength during healing. The clinical use of the double-docking technique of single-strand medial collateral ligament reconstruction should be considered because of its simplicity and initial strength. PMID:17368922

  13. Mechanical properties of UV irradiated rat tail tendon (RTT) collagen.

    PubMed

    Sionkowska, Alina; Wess, Tim

    2004-04-01

    The mechanical properties of RTT collagen tendon before and after UV irradiation have been investigated by mechanical testing (Instron). Air-dried tendon were submitted to treatment with UV irradiation (wavelength 254 nm) for different time intervals. The changes in such mechanical properties as breaking strength and percentage elongation have been investigated. The results have shown, that the mechanical properties of the tendon were greatly affected by time of UV irradiation. Ultimate tensile strength and ultimate percentage elongation decreased after UV irradiation of the tendon. Increasing UV irradiation leads to a decrease in Young's modulus of the tendon. PMID:15178003

  14. The role of animal models in tendon research

    PubMed Central

    Hast, M. W.; Zuskov, A.; Soslowsky, L. J.

    2014-01-01

    Tendinopathy is a debilitating musculoskeletal condition which can cause significant pain and lead to complete rupture of the tendon, which often requires surgical repair. Due in part to the large spectrum of tendon pathologies, these disorders continue to be a clinical challenge. Animal models are often used in this field of research as they offer an attractive framework to examine the cascade of processes that occur throughout both tendon pathology and repair. This review discusses the structural, mechanical, and biological changes that occur throughout tendon pathology in animal models, as well as strategies for the improvement of tendon healing. Cite this article: Bone Joint Res 2014;3:193–202. PMID:24958818

  15. Comparison of the effects of hamstring stretching using proprioceptive neuromuscular facilitation with prior application of cryotherapy or ultrasound therapy

    PubMed Central

    Magalhães, Francisco Elezier Xavier; Junior, Arlindo Rodrigues de Mesquita; Meneses, Harnold’s Tyson de Sousa; Moreira dos Santos, Rayele Pricila; Rodrigues, Ezaine Costa; Gouveia, Samara Sousa Vasconcelos; Gouveia, Guilherme Pertinni de Morais; Orsini, Marco; Bastos, Victor Hugo do Vale; Machado, Dionis de Castro Dutra

    2015-01-01

    [Purpose] Stretching using proprioceptive neuromuscular facilitation involve physiological reflex mechanisms through submaximal contraction of agonists which activate Golgi organ, promoting the relaxation reflex. The aim of this study was to evaluate the effects of proprioceptive neuromuscular facilitation alone and with prior application of cryotherapy and thermotherapy on hamstring stretching. [Subjects and Methods] The sample comprised of 32 young subjects with hamstring retraction of the right limb. The subjects were randomly allocated to four groups: the control, flexibility PNF, flexibility PNF associated with cryotherapy, flexibility PNF in association with ultrasound therapy. [Results] After 12 stretching sessions, experimental groups showed significant improvements compared to the control group. Moreover, we did not find any significant differences among the experimental groups indicating PNF stretching alone elicits similar results to PNF stretching with prior administration of cryotherapy or thermotherapy. [Conclusion] PNF without other therapy may be a more practical and less expensive choice for clinical care. PMID:26157261

  16. A Rare Case of Simultaneous Acute Bilateral Quadriceps Tendon Rupture and Unilateral Achilles Tendon Rupture

    PubMed Central

    Leong, Wei Yee; Gheorghiu, Daniel; Rao, Janardhan

    2013-01-01

    Introduction: There have been multiple reported cases of bilateral quadriceps tendon ruptures (QTR) in the literature. These injuries frequently associated with delayed diagnosis, which results in delayed surgical treatment. In very unusual cases, bilateral QTRs can be associated with other simultaneous tendon ruptures. Case Report: We present a rare case of bilateral QTR with a simultaneous Achilles Tendon Rupture involving a 31 years old Caucasian man who is a semi-professional body builder taking anabolic steroids. To date bilateral QTR with additional TA rupture has only been reported once in the literature and to our knowledge this is the first reported case of bilateral QTR and simultaneous TA rupture in a young, fit and healthy individual. Conclusion: The diagnosis of bilateral QTR alone can sometimes be challenging and the possibility of even further tendon injuries should be carefully assessed. A delay in diagnosis could result in delay in treatment and potentially worse outcome for the patient. PMID:27298913

  17. Prevention of peritendinous adhesions with electrospun chitosan-grafted polycaprolactone nanofibrous membranes.

    PubMed

    Chen, Shih-Hsien; Chen, Chih-Hao; Fong, Yi Teng; Chen, Jyh-Ping

    2014-12-01

    As one of the common complications after tendon injury and subsequent surgery, peritendinous adhesions could be minimized by directly placing a physical barrier between the injured site and the surrounding tissue. With the aim of solving the shortcomings of current biodegradable anti-adhesion barrier membranes, we propose the use of an electrospun chitosan-grafted polycaprolactone (PCL-g-CS) nanofibrous membrane (NFM) to prevent peritendinous adhesions. After introducing carboxyl groups on the surface by oxygen plasma treatment, the polycaprolactone (PCL) NFM was covalently grafted with chitosan (CS) molecules, with carbodiimide as the coupling agent. Compared with PCL NFM, PCL-g-CS NFM showed a similar fiber diameter, permeation coefficient for bovine serum albumin, ultimate tensile strain, reduced pore diameter, lower water contact angle, increased water sorption and tensile strength. With its submicrometer pore diameter (0.6-0.9μm), both NFMs could allow the diffusion of nutrients and waste while blocking fibroblast penetration to prevent adhesion formation after tendon surgery. Cell culture experiments verified that PCL-g-CS NFM can reduce fibroblast attachment while maintaining the biocompatibility of PCL NFM, implicating a synergistic anti-adhesion effect to raise the anti-adhesion efficacy. In vivo studies with a rabbit flexor digitorum profundus tendon surgery model confirmed that PCL-g-CS NFM effectively reduced peritendinous adhesion from gross observation, histology, joint flexion angle, gliding excursion and biomechanical evaluation. An injured tendon wrapped with PCL-g-CS NFM showed the same tensile strength as the naturally healed tendon, indicating that the anti-adhesion NFM will not compromise tendon healing. PMID:25192729

  18. Effect of Fatigue on Hamstring Reflex Responses and Posterior-Anterior Tibial Translation in Men and Women

    PubMed Central

    Behrens, Martin; Mau-Moeller, Anett; Wassermann, Franziska; Bruhn, Sven

    2013-01-01

    Anterior cruciate ligament (ACL) rupture ranks among the most common injuries in sports. The incidence of ACL injuries is considerably higher in females than in males and the underlying mechanisms are still under debate. Furthermore, it has been suggested that muscle fatigue can be a risk factor for ACL injuries. We investigated gender differences in hamstring reflex responses and posterior-anterior tibial translation (TT) before and after fatiguing exercise. We assessed the isolated movement of the tibia relative to the femur in the sagittal plane as a consequence of mechanically induced TT in standing subjects. The muscle activity of the hamstrings was evaluated. Furthermore, isometric maximum voluntary torque (iMVT) and rate of torque development (RTD) of the hamstrings (H) and quadriceps (Q) were measured and the MVT H/Q as well as the RTD H/Q ratios were calculated. After fatigue, reflex onset latencies were enhanced in women. A reduction of reflex responses associated with an increased TT was observed in females. Men showed no differences in these parameters. Correlation analysis revealed no significant associations between parameters for TT and MVT H/Q as well as RTD H/Q. The results of the present study revealed that the fatigue protocol used in this study altered the latency and magnitude of reflex responses of the hamstrings as well as TT in women. These changes were not found in men. Based on our results, it is conceivable that the fatigue-induced decrease in neuromuscular function with a corresponding increase in TT probably contributes to the higher incidence of ACL injuries in women. PMID:23573178

  19. Type of acute hamstring strain affects flexibility, strength, and time to return to pre‐injury level

    PubMed Central

    Askling, C; Saartok, T; Thorstensson, A

    2006-01-01

    Objectives To investigate possible links between aetiology of acute, first time hamstring strains in sprinters and dancers and recovery of flexibility, strength, and function as well as time to return to pre‐injury level. Methods Eighteen elite sprinters and 15 professional dancers with a clinically diagnosed hamstring strain were included. They were clinically examined and tested two, 10, 21, and 42 days after the acute injury. Range of motion in hip flexion and isometric strength in knee flexion were measured. Self estimated and actual time to return to pre‐injury level were recorded. Hamstring reinjuries were recorded during a two year follow up period. Results All the sprinters sustained their injuries during high speed sprinting, whereas all the dancers were injured while performing slow stretching type exercises. The initial loss of flexibility and strength was greater in sprinters than in dancers (p<0.05). At 42 days after injury, both groups could perform more than 90% of the test values of the uninjured leg. However, the actual times to return to pre‐injury level of performance were significantly longer (median 16 weeks (range 6–50) for the sprinters and 50 weeks (range 30–76) for the dancers). Three reinjuries were noted, all in sprinters. Conclusion There appears to be a link between the aetiologies of the two types of acute hamstring strain in sprinters and dancers and the time to return to pre‐injury level. Initially, sprinters have more severe functional deficits but recover more quickly. PMID:16371489

  20. Tendon Injuries of the Hand in Kirikkale, Turkey

    PubMed Central

    Sari, Elif

    2016-01-01

    BACKGROUND Tendon injuries are one of the most common injuries of the hand and challenging problems in trauma surgery. They usually require surgical repair and unlike the single tendon injuries, flexor tendon injuries have higher morbidities when accompanied with nerve injuries. In the present study, I aimed to report the clinical experiences and outcomes about tendon injuries. METHODS A total of 180 patients (149 males, 31 females) between 17 and 56 years old were operated in the clinic due to tendon injury. Seventy isolated extensor tendon injuries, 60 isolated flexor tendon injuries, 30 multiple flexor tendon and major nerve injuries, 18 combined extensor and flexor tendon injuries, and 2 combined extensor, flexor and major nerve injuries were treated. All patients were admitted to the clinic in acute phase and operated immediately. Physiotherapy was started in the third day of the operation. RESULTS Patients were followed up between 6 and 18 months (mean 12.4 months). There was not any major complications except one female patient (0.5%) who did not conform to the treatment protocol after flexor tendon injury. Fifteen patients (8.5%) had poor flexor range of motion. The other patients were healed uneventfully. CONCLUSION Tendon healing may cause some complications from mild to severe degrees. However, atraumatic surgery and a comprehensive postoperative early physiotherapy could decrease these complication rates.

  1. Bilateral patellar tendon rupture associated with statin use.

    PubMed

    Kearns, Marie C; Singh, Vinay K

    2016-01-01

    Patellar tendon rupture is an uncommon clinical presentation, which generally affects the under 40s who are active in sport. Bilateral rupture of both tendons is much rarer. It occurs most frequently in patients with predisposing factors such as corticosteroid use or systemic diseases. The authors present the case of a 56-year-old male on long-term statin therapy who sustained this injury following a fall on ice. He had no known risk factors for tendon rupture. Surgical treatment involved tendon repair using Krakow suture via bony tunnels in the patella. Statins have previously been associated with tendon ruptures at other sites but there have been no published cases of bilateral patellar tendon rupture linked to statin use. We review the literature regarding the association between statins and tendon rupture. PMID:27165749

  2. Bilateral patellar tendon rupture associated with statin use

    PubMed Central

    Kearns, Marie C.; Singh, Vinay K.

    2016-01-01

    Patellar tendon rupture is an uncommon clinical presentation, which generally affects the under 40s who are active in sport. Bilateral rupture of both tendons is much rarer. It occurs most frequently in patients with predisposing factors such as corticosteroid use or systemic diseases. The authors present the case of a 56-year-old male on long-term statin therapy who sustained this injury following a fall on ice. He had no known risk factors for tendon rupture. Surgical treatment involved tendon repair using Krakow suture via bony tunnels in the patella. Statins have previously been associated with tendon ruptures at other sites but there have been no published cases of bilateral patellar tendon rupture linked to statin use. We review the literature regarding the association between statins and tendon rupture. PMID:27165749

  3. Anatomical heterogeneity of tendon: Fascicular and interfascicular tendon compartments have distinct proteomic composition

    PubMed Central

    Thorpe, Chavaunne T.; Peffers, Mandy J.; Simpson, Deborah; Halliwell, Elizabeth; Screen, Hazel R. C.; Clegg, Peter D.

    2016-01-01

    Tendon is a simple aligned fibre composite, consisting of collagen-rich fascicles surrounded by a softer interfascicular matrix (IFM). The composition and interactions between these material phases are fundamental in ensuring tissue mechanics meet functional requirements. However the IFM is poorly defined, therefore tendon structure-function relationships are incompletely understood. We hypothesised that the IFM has a more complex proteome, with faster turnover than the fascicular matrix (FM). Using laser-capture microdissection and mass spectrometry, we demonstrate that the IFM contains more proteins, and that many proteins show differential abundance between matrix phases. The IFM contained more protein fragments (neopeptides), indicating greater matrix degradation in this compartment, which may act to maintain healthy tendon structure. Protein abundance did not alter with ageing, but neopeptide numbers decreased in the aged IFM, indicating decreased turnover which may contribute to age-related tendon injury. These data provide important insights into how differences in tendon composition and turnover contribute to tendon structure-function relationships and the effects of ageing. PMID:26842662

  4. Comparison of hamstring muscle behavior for anterior cruciate ligament (ACL) patient and normal subject during local marching

    NASA Astrophysics Data System (ADS)

    Amineldin@Aminudin, Nurul Izzaty Bt.; Rambely, A. S.

    2014-09-01

    This study aims to investigate the hamstring muscle activity after the surgery by carrying out an electromyography experiment on the hamstring and to compare the behavior of the ACL muscle activity between ACL patient and control subject. Electromyography (EMG) is used to study the behavior of muscles during walking activity. Two hamstring muscles involved which are semitendinosus and bicep femoris. The EMG data for both muscles were recorded while the subject did maximum voluntary contraction (MVC) and marching. The study concluded that there were similarities between bicep femoris of the ACL and control subjects. The analysis showed that the biceps femoris muscle of the ACL subject had no abnormality and the pattern is as normal as the control subject. However, ACL patient has poor semitendinosus muscle strength compared to that of control subject because the differences of the forces produced. The force of semitendinosus value for control subject was two times greater than that of the ACL subject as the right semitendinosus muscle of ACL subject was used to replace the anterior cruciate ligament (ACL) that was injured.

  5. Minimally Invasive Approach to Achilles Tendon Pathology.

    PubMed

    Hegewald, Kenneth W; Doyle, Matthew D; Todd, Nicholas W; Rush, Shannon M

    2016-01-01

    Many surgical procedures have been described for Achilles tendon pathology; however, no overwhelming consensus has been reached for surgical treatment. Open repair using a central or paramedian incision allows excellent visualization for end-to-end anastomosis in the case of a complete rupture and detachment and reattachment for insertional pathologies. Postoperative wound dehiscence and infection in the Achilles tendon have considerable deleterious effects on overall functional recovery and outcome and sometimes require plastic surgery techniques to achieve coverage. With the aim of avoiding such complications, foot and ankle surgeons have studied less invasive techniques for repair. We describe a percutaneous approach to Achilles tendinopathy using a modification of the Bunnell suture weave technique combined with the use of interference screws. No direct end-to-end repair of the tendon is performed, rather, the proximal stump is brought in direct proximity of the distal stump, preventing overlengthening and proximal stump retraction. This technique also reduces the suture creep often seen with end-to-end tendon repair by providing a direct, rigid suture to bone interface. We have used the new technique to minimize dissection and exposure while restoring function and accelerating recovery postoperatively. PMID:26385574

  6. Achilles Tendon Repair, A Modified Technique

    PubMed Central

    Keyhani, Sohrab; Mardani-Kivi, Mohsen; Abbasian, Mohammadreza; Emami-Moghaddam Tehrani, Mohammad; Lahiji, Farivar Abdollahzadeh

    2013-01-01

    Background: Wound complications following open repair for acute Achilles tendon ruptures (AATR) remain the subject of significant debate. The aim of this study is to investigate the effects of covering repaired AATR using well-nourished connective tissues (paratenon and deep fascia) to avoid complications after open repair. Methods: In this case series study, open repair was performed for 32 active young patients with AATR. After the tendon was repaired, the deep fascia and paratenon was used to cover the Achilles tendon. Patients were followed for two years and any wound complication was recorded. During the last visit, the American Orthopedic Foot and Ankle Society (AOFAS) ankle-hind foot score was completed for all patients. Calf circumference and ankle range of motion were measured and compared with the contralateral side. Patients were asked about returning to previous sports activities and limitations with footwear. Results: Only, one patient developed deep wound infection (3%). None of the patients had any discomfort around the operation area, limitation with footwear, sural nerve injury, re-rupture, and skin adhesion. The AOFAS score averaged 92.5±6. Two patients (7%) were unable to return to previous sports activities because of moderate pain in heavy physical exercises. The calf circumference and ankle ROM were similar between healthy and operated sides. Conclusion: The present study showed that fascial envelope for full covering of the repaired Achilles tendon may help to prevent the occurrence of wound complications. PMID:25207295

  7. In vitro fatigue of human tendons.

    PubMed

    Schechtman, H; Bader, D L

    1997-08-01

    The purpose of this study was to determine the fatigue behaviour of human tendons in vitro. The testing was accomplished with the use of specially designed grips and the local measurement of tendon cross-sectional area. Ninety specimens prepared from Extensor digitorum longus (EDL) tendons of the foot were subjected to a cyclic square tension-tension stress waveform at physiological frequencies. The maximum tensile stress was normalised to values corresponding to prescribed levels between 10% and 90% of the calculated ultimate tensile strength (UTS) of 100 MPa. The minimum stress was set at 1% of the UTS. A replication of 10 specimens per stress level allowed the use of statistical models for the distribution of fatigue life. Results followed a linear model, of form S = 101.3 - 14.8 log(N), relating the normalised stress to the median number of cycles to failure, therefore suggesting the absence of an endurance limit. The Weibull distribution was found to describe adequately the probability of failure at each stress level. A model which takes into account in vivo healing was proposed. This model was able to explain the presence of intact tendons throughout the lifetime of an individual. PMID:9239568

  8. On muscle, tendon and high heels.

    PubMed

    Csapo, R; Maganaris, C N; Seynnes, O R; Narici, M V

    2010-08-01

    Wearing high heels (HH) places the calf muscle-tendon unit (MTU) in a shortened position. As muscles and tendons are highly malleable tissues, chronic use of HH might induce structural and functional changes in the calf MTU. To test this hypothesis, 11 women regularly wearing HH and a control group of 9 women were recruited. Gastrocnemius medialis (GM) fascicle length, pennation angle and physiological cross-sectional area (PCSA), the Achilles' tendon (AT) length, cross-sectional area (CSA) and mechanical properties, and the plantarflexion torque-angle and torque-velocity relationships were assessed in both groups. Shorter GM fascicle lengths were observed in the HH group (49.6+/-5.7 mm vs 56.0+/-7.7 mm), resulting in greater tendon-to-fascicle length ratios. Also, because of greater AT CSA, AT stiffness was higher in the HH group (136.2+/-26.5 N mm(-1) vs 111.3+/-20.2 N mm(-1)). However, no differences in the GM PCSA to AT CSA ratio, torque-angle and torque-velocity relationships were found. We conclude that long-term use of high-heeled shoes induces shortening of the GM muscle fascicles and increases AT stiffness, reducing the ankle's active range of motion. Functionally, these two phenomena seem to counteract each other since no significant differences in static or dynamic torques were observed. PMID:20639419

  9. Changes in Achilles tendon mechanical properties following eccentric heel drop exercise are specific to the free tendon.

    PubMed

    Obst, S J; Newsham-West, R; Barrett, R S

    2016-04-01

    Mechanical loading of the Achilles tendon during isolated eccentric contractions could induce immediate and region-dependent changes in mechanical properties. Three-dimensional ultrasound was used to examine the immediate effect of isolated eccentric exercise on the mechanical properties of the distal (free tendon) and proximal (gastrocnemii) regions of the Achilles tendon. Participants (n = 14) underwent two testing sessions in which tendon measurements were made at rest and during a 30% and 70% isometric plantar flexion contractions immediately before and after either: (a) 3 × 15 eccentric heel drops or (b) 10-min rest. There was a significant time-by-session interaction for free tendon length and strain for all loading conditions (P < 0.05). Pairwise comparisons revealed a significant increase in free tendon length and strain at all contraction intensities after eccentric exercise (P < 0.05). There was no significant time-by-session interaction for the gastrocnemii (medial or lateral) aponeurosis or tendon for any of the measured parameters. Immediate changes in Achilles tendon mechanical properties were specific to the free tendon and consistent with changes due to mechanical creep. These findings suggest that the mechanical properties of the free tendon may be more vulnerable to change with exercise compared with the gastrocnemii aponeurosis or tendon. PMID:25919320

  10. A new harvest site for bone graft in anterior cruciate ligament revision surgery.

    PubMed

    Franceschi, Francesco; Papalia, Rocco; Di Martino, Alberto; Rizzello, Giacomo; Allaire, Robert; Denaro, Vincenzo

    2007-05-01

    During revision anterior cruciate ligament (ACL) surgery, femoral interference screws frequently require removal. This may lead to significant tunnel widening and possible graft fixation failure as a result. Solutions include drilling the revision tunnel in a different location, using stacked interference screws, or using bone graft to fill the defect. Autogenous iliac crest graft and allograft are both used, but there are significant comorbidities associated with each. We developed a new technique for harvesting autogenous bone graft that avoids many of the complications associated with other graft sources. By use of the existing surgical incision from the initial harvest of the bone-patellar tendon-bone autograft, bone from the medial tibial metaphyseal safe zone is harvested via an OATS tube harvester (Arthrex, Naples, FL). A bone plug 1 mm larger in size than the femoral defect is harvested and arthroscopically inserted via a press-fit technique. At 3 months after bone grafting, patients undergo revision ACL reconstruction. The proximal tibial metaphysis is a safe bone graft harvest site in revision ACL surgery and offers an effective method for filling large bony defects, allowing anatomic reconstruction of the ACL after bone healing has occurred. Furthermore, it eliminates the problems associated with allograft or use of a remote graft donor site. PMID:17478290

  11. The Effectiveness of Injury Prevention Programs to Modify Risk Factors for Non-Contact Anterior Cruciate Ligament and Hamstring Injuries in Uninjured Team Sports Athletes: A Systematic Review

    PubMed Central

    Monajati, Alireza; Larumbe-Zabala, Eneko; Goss-Sampson, Mark; Naclerio, Fernando

    2016-01-01

    Background Hamstring strain and anterior cruciate ligament injuries are, respectively, the most prevalent and serious non-contact occurring injuries in team sports. Specific biomechanical and neuromuscular variables have been used to estimate the risk of incurring a non-contact injury in athletes. Objective The aim of this study was to systematically review the evidences for the effectiveness of injury prevention protocols to modify biomechanical and neuromuscular anterior cruciate and/or hamstring injuries associated risk factors in uninjured team sport athletes. Data Sources PubMed, Science Direct, Web of Science, Cochrane Libraries, U.S. National Institutes of Health clinicaltrials.gov, Sport Discuss and Google Scholar databases were searched for relevant journal articles published until March 2015. A manual review of relevant articles, authors, and journals, including bibliographies was performed from identified articles. Main Results Nineteen studies were included in this review. Four assessment categories: i) landing, ii) side cutting, iii) stop-jump, and iv) muscle strength outcomes, were used to analyze the effectiveness of the preventive protocols. Eight studies using multifaceted interventions supported by video and/or technical feedback showed improvement in landing and/or stop-jump biomechanics, while no effects were observed on side-cutting maneuver. Additionally, multifaceted programs including hamstring eccentric exercises increased hamstring strength, hamstring to quadriceps functional ratio and/or promoted a shift of optimal knee flexion peak torque toward a more open angle position. Conclusions Multifaceted programs, supported by proper video and/or technical feedback, including eccentric hamstring exercises would positively modify the biomechanical and or neuromuscular anterior cruciate and/or hamstring injury risk factors. PMID:27171282

  12. Hamstring Architectural and Functional Adaptations Following Long vs. Short Muscle Length Eccentric Training.

    PubMed

    Guex, Kenny; Degache, Francis; Morisod, Cynthia; Sailly, Matthieu; Millet, Gregoire P

    2016-01-01

    Most common preventive eccentric-based exercises, such as Nordic hamstring do not include any hip flexion. So, the elongation stress reached is lower than during the late swing phase of sprinting. The aim of this study was to assess the evolution of hamstring architectural (fascicle length and pennation angle) and functional (concentric and eccentric optimum angles and concentric and eccentric peak torques) parameters following a 3-week eccentric resistance program performed at long (LML) vs. short muscle length (SML). Both groups performed eight sessions of 3-5 × 8 slow maximal eccentric knee extensions on an isokinetic dynamometer: the SML group at 0° and the LML group at 80° of hip flexion. Architectural parameters were measured using ultrasound imaging and functional parameters using the isokinetic dynamometer. The fascicle length increased by 4.9% (p < 0.01, medium effect size) in the SML and by 9.3% (p < 0.001, large effect size) in the LML group. The pennation angle did not change (p = 0.83) in the SML and tended to decrease by 0.7° (p = 0.09, small effect size) in the LML group. The concentric optimum angle tended to decrease by 8.8° (p = 0.09, medium effect size) in the SML and by 17.3° (p < 0.01, large effect size) in the LML group. The eccentric optimum angle did not change (p = 0.19, small effect size) in the SML and tended to decrease by 10.7° (p = 0.06, medium effect size) in the LML group. The concentric peak torque did not change in the SML (p = 0.37) and the LML (p = 0.23) groups, whereas eccentric peak torque increased by 12.9% (p < 0.01, small effect size) and 17.9% (p < 0.001, small effect size) in the SML and the LML group, respectively. No group-by-time interaction was found for any parameters. A correlation was found between the training-induced change in fascicle length and the change in concentric optimum angle (r = -0.57, p < 0.01). These results suggest that performing eccentric exercises lead to several architectural and

  13. Hamstring Architectural and Functional Adaptations Following Long vs. Short Muscle Length Eccentric Training

    PubMed Central

    Guex, Kenny; Degache, Francis; Morisod, Cynthia; Sailly, Matthieu; Millet, Gregoire P.

    2016-01-01

    Most common preventive eccentric-based exercises, such as Nordic hamstring do not include any hip flexion. So, the elongation stress reached is lower than during the late swing phase of sprinting. The aim of this study was to assess the evolution of hamstring architectural (fascicle length and pennation angle) and functional (concentric and eccentric optimum angles and concentric and eccentric peak torques) parameters following a 3-week eccentric resistance program performed at long (LML) vs. short muscle length (SML). Both groups performed eight sessions of 3–5 × 8 slow maximal eccentric knee extensions on an isokinetic dynamometer: the SML group at 0° and the LML group at 80° of hip flexion. Architectural parameters were measured using ultrasound imaging and functional parameters using the isokinetic dynamometer. The fascicle length increased by 4.9% (p < 0.01, medium effect size) in the SML and by 9.3% (p < 0.001, large effect size) in the LML group. The pennation angle did not change (p = 0.83) in the SML and tended to decrease by 0.7° (p = 0.09, small effect size) in the LML group. The concentric optimum angle tended to decrease by 8.8° (p = 0.09, medium effect size) in the SML and by 17.3° (p < 0.01, large effect size) in the LML group. The eccentric optimum angle did not change (p = 0.19, small effect size) in the SML and tended to decrease by 10.7° (p = 0.06, medium effect size) in the LML group. The concentric peak torque did not change in the SML (p = 0.37) and the LML (p = 0.23) groups, whereas eccentric peak torque increased by 12.9% (p < 0.01, small effect size) and 17.9% (p < 0.001, small effect size) in the SML and the LML group, respectively. No group-by-time interaction was found for any parameters. A correlation was found between the training-induced change in fascicle length and the change in concentric optimum angle (r = −0.57, p < 0.01). These results suggest that performing eccentric exercises lead to several architectural and

  14. Effects of a Stretching Development and Maintenance Program on Hamstring Extensibility in Schoolchildren: A Cluster-Randomized Controlled Trial

    PubMed Central

    Mayorga-Vega, Daniel; Merino-Marban, Rafael; Manzano-Lagunas, Jorge; Blanco, Humberto; Viciana, Jesús

    2016-01-01

    The main purpose of the present study was to examine the effects of a physical education-based stretching development and maintenance program on hamstring extensibility in schoolchildren. A sample of 150 schoolchildren aged 7-10 years old from a primary school participated in the present study (140 participants were finally included). The six classes balanced by grade were cluster randomly assigned to the experimental group 1 (n = 51), experimental group 2 (n = 51) or control group (n = 49) (i.e., a cluster randomized controlled trial design was used). During the physical education classes, the students from the experimental groups 1 and 2 performed a four-minute stretching program twice a week for nine weeks (first semester). Then, after a five-week period of detraining coinciding with the Christmas holidays, the students from the experimental groups 1 and 2 completed another stretching program twice a week for eleven weeks (second semester). The students from the experimental group 1 continued performing the stretching program for four minutes while those from the experimental group 2 completed a flexibility maintenance program for only one minute. The results of the two-way analysis of variance showed that the physical education-based stretching development program significantly improved the students’ hamstring extensibility (p < 0.001), as well as that these gains obtained remained after the stretching maintenance program (p < 0.001). Additionally, statistically significant differences between the two experimental groups were not found (p > 0.05). After a short-term stretching development program, a physical education-based stretching maintenance program of only one-minute sessions twice a week is effective in maintaining hamstring extensibility among schoolchildren. This knowledge could help and guide teachers to design programs that allow a feasible and effective development and maintenance of students’ flexibility in the physical education setting. Key

  15. EGR1 and EGR2 involvement in vertebrate tendon differentiation.

    PubMed

    Lejard, Véronique; Blais, Frédéric; Guerquin, Marie-Justine; Bonnet, Aline; Bonnin, Marie-Ange; Havis, Emmanuelle; Malbouyres, Maryline; Bidaud, Christelle Bonod; Maro, Géraldine; Gilardi-Hebenstreit, Pascale; Rossert, Jérome; Ruggiero, Florence; Duprez, Delphine

    2011-02-18

    The molecules involved in vertebrate tendon formation during development remain largely unknown. To date, only two DNA-binding proteins have been identified as being involved in vertebrate tendon formation, the basic helix-loop-helix transcription factor Scleraxis and, recently, the Mohawk homeobox gene. We investigated the involvement of the early growth response transcription factors Egr1 and Egr2 in vertebrate tendon formation. We established that Egr1 and Egr2 expression in tendon cells was correlated with the increase of collagen expression during tendon cell differentiation in embryonic limbs. Vertebrate tendon differentiation relies on a muscle-derived FGF (fibroblast growth factor) signal. FGF4 was able to activate the expression of Egr genes and that of the tendon-associated collagens in chick limbs. Egr gene misexpression experiments using the chick model allowed us to establish that either Egr gene has the ability to induce de novo expression of the reference tendon marker scleraxis, the main tendon collagen Col1a1, and other tendon-associated collagens Col3a1, Col5a1, Col12a1, and Col14a1. Mouse mutants for Egr1 or Egr2 displayed reduced amounts of Col1a1 transcripts and a decrease in the number of collagen fibrils in embryonic tendons. Moreover, EGR1 and EGR2 trans-activated the mouse Col1a1 proximal promoter and were recruited to the tendon regulatory regions of this promoter. These results identify EGRs as novel DNA-binding proteins involved in vertebrate tendon differentiation by regulating type I collagen production. PMID:21173153

  16. A new approach to assess the spasticity in hamstrings muscles using mechanomyography antagonist muscular group.

    PubMed

    Krueger, Eddy; Scheeren, Eduardo M; Nogueira-Neto, Guilherme N; Button, Vera Lúcia da S N; Nohama, Percy

    2012-01-01

    Several pathologies can cause muscle spasticity. Modified Ashworth scale (MAS) can rank spasticity, however its results depend on the physician subjective evaluation. This study aims to show a new approach to spasticity assessment by means of MMG analysis of hamstrings antagonist muscle group (quadriceps muscle). Four subjects participated in the study, divided into two groups regarding MAS (MAS0 and MAS1). MMG sensors were positioned over the muscle belly of rectus femoris (RF), vastus lateralis (VL) and vastus medialis (VM) muscles. The range of movement was acquired with an electrogoniometer placed laterally to the knee. The system was based on a LabVIEW acquisition program and the MMG sensors were built with triaxial accelerometers. The subjects were submitted to stretching reflexes and the integral of the MMG (MMG(INT)) signal was calculated to analysis. The results showed that the MMG(INT) was greater to MAS1 than to MAS0 [muscle RF (p = 0.004), VL (p = 0.001) and VM (p = 0.007)]. The results showed that MMG was viable to detect a muscular tonus increase in antagonist muscular group (quadriceps femoris) of spinal cord injured volunteers. PMID:23366325

  17. The comparison of the immediate effects of application of the suboccipital muscle inhibition and self-myofascial release techniques in the suboccipital region on short hamstring.

    PubMed

    Cho, Sung-Hak; Kim, Soo-Han; Park, Du-Jin

    2015-01-01

    [Purpose] The purpose of this study was to research the effect of performing the suboccipital muscle inhibition (SMI) and self-myofascial release (SMFR) techniques in the suboccipital area on the flexibility of the hamstring. [Subjects] Fifty persons with short hamstrings participated in this research. According to the results of the finger-floor distance (FFD) test, the subjects were allocated to SMI and SMFR groups of 25 subjects each. [Methods] The SMI and SMFR techniques were applied to the groups. For the analysis, we used the FFD test and the straight leg raise (SLR) test for the flexibility of hamstring. The evaluator was blindfolded. [Results] In the SMI group, FFD, SLR, and PA were significantly changed after the intervention, and in the SMFR group, there was a significant change in SLR after the intervention. In a comparison between the groups, FED was found to be significantly increased in the SMI group. [Conclusion] Application of the SMI and SMFR to persons with short hamstrings resulted in immediate increases in flexibility of the hamstring. However, we could see that the SMI technique was more effective. PMID:25642072

  18. A Tendon Cell Specific RNAi Screen Reveals Novel Candidates Essential for Muscle Tendon Interaction.

    PubMed

    Tiwari, Prabhat; Kumar, Arun; Das, Rudra Nayan; Malhotra, Vivek; VijayRaghavan, K

    2015-01-01

    Tendons are fibrous connective tissue which connect muscles to the skeletal elements thus acting as passive transmitters of force during locomotion and provide appropriate body posture. Tendon-derived cues, albeit poorly understood, are necessary for proper muscle guidance and attachment during development. In the present study, we used dorsal longitudinal muscles of Drosophila and their tendon attachment sites to unravel the molecular nature of interactions between muscles and tendons. We performed a genetic screen using RNAi-mediated knockdown in tendon cells to find out molecular players involved in the formation and maintenance of myotendinous junction and found 21 candidates out of 2507 RNAi lines screened. Of these, 19 were novel molecules in context of myotendinous system. Integrin-βPS and Talin, picked as candidates in this screen, are known to play important role in the cell-cell interaction and myotendinous junction formation validating our screen. We have found candidates with enzymatic function, transcription activity, cell adhesion, protein folding and intracellular transport function. Tango1, an ER exit protein involved in collagen secretion was identified as a candidate molecule involved in the formation of myotendinous junction. Tango1 knockdown was found to affect development of muscle attachment sites and formation of myotendinous junction. Tango1 was also found to be involved in secretion of Viking (Collagen type IV) and BM-40 from hemocytes and fat cells. PMID:26488612

  19. A Tendon Cell Specific RNAi Screen Reveals Novel Candidates Essential for Muscle Tendon Interaction

    PubMed Central

    Tiwari, Prabhat; Malhotra, Vivek; VijayRaghavan, K.

    2015-01-01

    Tendons are fibrous connective tissue which connect muscles to the skeletal elements thus acting as passive transmitters of force during locomotion and provide appropriate body posture. Tendon-derived cues, albeit poorly understood, are necessary for proper muscle guidance and attachment during development. In the present study, we used dorsal longitudinal muscles of Drosophila and their tendon attachment sites to unravel the molecular nature of interactions between muscles and tendons. We performed a genetic screen using RNAi-mediated knockdown in tendon cells to find out molecular players involved in the formation and maintenance of myotendinous junction and found 21 candidates out of 2507 RNAi lines screened. Of these, 19 were novel molecules in context of myotendinous system. Integrin-βPS and Talin, picked as candidates in this screen, are known to play important role in the cell-cell interaction and myotendinous junction formation validating our screen. We have found candidates with enzymatic function, transcription activity, cell adhesion, protein folding and intracellular transport function. Tango1, an ER exit protein involved in collagen secretion was identified as a candidate molecule involved in the formation of myotendinous junction. Tango1 knockdown was found to affect development of muscle attachment sites and formation of myotendinous junction. Tango1 was also found to be involved in secretion of Viking (Collagen type IV) and BM-40 from hemocytes and fat cells. PMID:26488612

  20. Mechanical properties of stapedial tendon in human middle ear.

    PubMed

    Cheng, Tao; Gan, Rong Z

    2007-12-01

    Measurement on mechanical properties of the stapedial tendon in human middle ear has not been reported in the literature. In this paper, we used the material testing system to conduct uniaxial tensile, stress relaxation, and failure tests on stapedial tendon specimens harvested from human temporal bones. The digital image correlation method was employed to assess the boundary effect on experimental data. The stress-strain relationship of the tendon obtained from experiments was analyzed using the hyperelastic Ogden model. The results presented include (1) the constitutive equation of the tendon for stretch ratio of 1-1.4 or stress range of 0-1.45 MPa, (2) the mean ultimate stress and stretch ratio of the tendon at 4.04 MPa and 1.65, respectively, and (3) the hysteresis and normalized stress relaxation function of the tendon. The data reported in this paper contribute to ear mechanics, especially for theoretical analysis of human ear function. PMID:18067396

  1. An efficient robotic tendon for gait assistance.

    PubMed

    Hollander, Kevin W; Ilg, Robert; Sugar, Thomas G; Herring, Donald

    2006-10-01

    A robotic tendon is a spring based, linear actuator in which the stiffness of the spring is crucial for its successful use in a lightweight, energy efficient, powered ankle orthosis. Like its human analog, the robotic tendon uses its inherent elastic nature to reduce both peak power and energy requirements for its motor. In the ideal example, peak power required of the motor for ankle gait is reduced from 250 W to just 77 W. In addition, ideal energy requirements are reduced from nearly 36 J to just 21 J. Using this approach, an initial prototype has provided 100% of the power and energy necessary for ankle gait in a compact 0.95 kg package, seven times less than an equivalent motor/gearbox system. PMID:16995768

  2. Quadriceps Tendon Rupture due to Postepileptic Convulsion

    PubMed Central

    Erkut, Adem; Guvercin, Yilmaz; Sahin, Rifat; Keskin, Davut

    2014-01-01

    We present a case of quadriceps tendon (QT) rupture. QT ruptures can occur in all ages. The cause is mostly traumatic in origin. Spontaneous ruptures that are thought to result from predisposing conditions are rare. Post-convulsion QT ruptures lacking traumas in their history can be overlooked in clinical examinations. This should be born in mind by the attending physician, as early diagnosis and treatment of the condition can lead to satisfactory outcomes. PMID:24944977

  3. Ligament reconstruction tendon interposition with mersilene augmentation.

    PubMed

    Stein, Andrew J; Schofield, Jennifer L; Marsh, Mike; Paulo, Jerry

    2011-03-01

    Many surgical procedures have been described for the treatment of thumb basilar joint osteoarthritis. Augmentation of the standard ligament reconstruction tendon interposition procedure with the use of a Mersilene suture tape suspension-plasty, to recreate the stability provided by the anterior oblique ligament and increase pinch strength, will be described. Satisfaction with this procedure was evaluated through surveys completed by patients. In addition, independent physical assessments were performed to demonstrate stability, range of motion, and strength. PMID:21358518

  4. Triceps tendon avulsion and associated injuries of the elbow

    PubMed Central

    Canbora, Kerem; Ozyurek, Selahattin; Gumussuyu, Gurkan; Kose, Ozkan

    2013-01-01

    A rupture or avulsion of the triceps tendon is very rare but concomitant elbow injuries with avulsion of the triceps tendon are even rarer. In this study, an extraordinary and unusual injury combination (radial head and trochlear fracture associated with triceps tendon avulsion), which happened during a fall onto the elbow with outstretched hand, was identified and has been discussed in the literature. PMID:23667221

  5. Low level laser therapy in healing tendon

    NASA Astrophysics Data System (ADS)

    Carvalho, P. T. C.; Batista, Cheila O. C.; Fabíola, C.

    2005-11-01

    This study aims to verify the effects of AsGa Laser in the scarring of tendon lesion in rats with low nourishment condition and to analyze the ideal light density by means of histopathologic findings highlighted by light microscopy. After the proposed nutritional condition was verified the animals were divided into 3 groups denominated as follows: GI control group, GII laser 1 J/sq.cm. and GIII laser 4 J/sq.cm. The lesions were induced by means of routine surgical process for tendon exposure: There was a crushing process with Allis pincers followed by saturated incision. The data obtained in relation to the amount of macrophage, leukocyte, fibroblast, vessel neoformation, fibrosis and collagen were submitted to parametric statistic procedures of variance analysis and "Tukey" Test and the result obtained was p < 0,05. According to the obtained results it can be concluded that low power laser therapy proved to be efficient in tendon repairing even though the animals suffered from malnutrition as well as the 1 J energy density proved to be more efficient in this case.

  6. How High Glucose Levels Affect Tendon Homeostasis.

    PubMed

    Snedeker, Jess G

    2016-01-01

    Among the many factors playing a role in tendon disease, unregulated biochemical reactions between glucose and the collagen extracellular matrix are coming increasingly into focus. We have shown that formation of advanced glycation end-products that cross-link the collagen extracellular matrix can drastically affect cellular level mechanical properties of the matrix, and in turn affect cell-level biomechanical stimuli during physiological loading of the tissue. We suggest that these may adversely affect tendon cell response to matrix damage, as well as the quality of the consequent repair. If such mechanical feedback loops are altered, the ability of tendon cells to maintain tissue in a functional, healthy state may be compromised. Although key foundational elements of biochemical, biomechanical, and biological understanding are now in place, the full extent of how these aspects interact, including the precise mechanisms by which advanced glycation end-products pathologically disrupt connective tissue homeostasis and damage repair, are only beginning to be adequately appreciated. PMID:27535261

  7. An Artificial Tendon with Durable Muscle Interface

    PubMed Central

    Melvin, Alan; Litsky, Alan; Mayerson, Joel; Witte, David; Melvin, David; Juncosa-Melvin, Natalia

    2010-01-01

    A coupling mechanism that can permanently fix a forcefully contracting muscle to a bone anchor or any totally inert prosthesis would meet a serious need in orthopaedics. Our group developed the OrthoCoupler™ device to satisfy these demands. The objective of this study was to test OrthoCoupler’s performance in vitro and in vivo in the goat semitendinosus tendon model. For in vitro evaluation, 40 samples were fatigue-tested, cycling at 10 load levels, n=4 each. For in vivo evaluation, the semitendinosus tendon was removed bilaterally in 8 goats. Left sides were reattached with an OrthoCoupler, and right sides were reattached using the Krackow stitch with #5 braided polyester sutures. Specimens were harvested 60 days post-surgery and assigned for biomechanics and histology. Fatigue strength of the devices in vitro was several times the contractile force of the semitendinosus muscle. The in vivo devices were built equivalent to two of the in vitro devices, providing an additional safety factor. In strength testing at necropsy, suture controls pulled out at 120.5 ± 68.3 N, whereas each OrthoCoupler was still holding after the muscle tore, remotely, at 298±111.3N (mean ± SD)(p<0.0003). Muscle tear strength was reached with the fiber-muscle composite produced in healing still soundly intact. This technology may be of value for orthopaedic challenges in oncology, revision arthroplasty, tendon transfer, and sports-injury reconstruction. PMID:19639642

  8. Sex, Age, and Graft Size as Predictors of ACL Re-tear

    PubMed Central

    Nguyen, Duong

    2016-01-01

    Objectives: The minimum size required for a successful quadrupled hamstring autograft ACL reconstruction remains controversial. The risks of ACL re-tear in younger patients who tend to participate in a higher level of sports activity, and female athletes who have numerous predisposing factors, are poorly defined. Purpose: To identify risk factors for graft re-tears within 2 years of ACL surgery. The hypotheses are that female sex, a smaller size graft, and younger patients will increase the odds of failure. Study Design Cohort Study. Level of evidence, 3. Methods: A cohort of 503 athletes undergoing primary, autograft hamstring ACL reconstruction, performed by a single surgeon using the same surgical technique and rehabilitation protocol, between September-December 2012, was followed for a total duration of 2 years. Return to play was allowed between 6 and 12 months post-surgery upon completion of functional testing. Exclusion criteria included infections, revisions, double bundle techniques, multi-ligament injuries, non-compliance, BTB/allografts/hybrid grafts. Primary outcome consisted of binary data (ACL graft re-tear or no tear) as measured on physical exam (Lachman and pivot shift) and MRI. Multivariate logistic regression statistical analysis with model fitting was used to investigate the predictive value of sex, age, and graft size on ACL re-tear. Secondary sensitivity analyses were performed on the adolescent subgroup, age and graft size as categorical variables, and testing for interactions among variables. Sample size was calculated based on the rule of 10 events per independent variable for logistic regression. Results: The mean age of the 503 athletes was 27.5 (SD 10.6; range = 12-61). There were 235 females (47%) and 268 males (53%) with a 6% rate of re-tears (28 patients; 17 females). Mean graft size was 7.9 (SD 0.6; range = 6-10). Univariate analyses of graft size, sex, and age only in the model showed that younger age (odds ratio [OR] = 0.86; 95

  9. Comparison of modified Kessler tendon suture at different levels in the human flexor digitorum profundus tendon and porcine flexors and porcine extensors: an experimental biomechanical study.

    PubMed

    Havulinna, J; Leppänen, O V; Järvinen, T L N; Göransson, H

    2011-10-01

    This study compared the biomechanical behaviour of repairs in the human flexor digitorum profundus tendon in zones I, II and III with repairs of different segments of the porcine flexor tendon of the second digit and the extensor digiti quarti proprius tendon, in order to assess the validity of porcine tendons as models for human flexor tendon repairs. These porcine tendons were selected after comparing their size with the human flexor digitorum profundus tendon. The tendon repairs were done in three segments of each porcine tendon and repairs in the human tendons were done in zones I,II and III. Ten tendons in each group yielded a total of 90 specimens. A modified Kessler repair was done with 3-0 coated braided polyester suture and subjected to uniaxial tensile testing. In human flexor tendons, the ultimate force was higher in zones I and II than in zone III. The porcine flexor digitorum profundus tendon from the second digit and the proximal segment of the extensor digiti quarti proprius tendon behaved similarly to the human flexor tendon in zone III and can be considered as surrogates for the human flexor tendon. PMID:21816887

  10. A novel postoperative immobilization model for murine Achilles tendon sutures.

    PubMed

    Shibuya, Yoichiro; Takayama, Yuzo; Kushige, Hiroko; Jacinto, Sandra; Sekido, Mitsuru; Kida, Yasuyuki S

    2016-08-01

    The body's motion and function are all in part effected by a vital tissue, the tendon. Tendon injury often results in limited functioning after postoperative procedures and even for a long time after rehabilitation. Although numerous studies have reported surgical procedures using animal models which have contributed to both basic and clinical research, modeling of tendon sutures or postoperative immobilizations has not been performed on small experimental animals, such as mice. In this study we have developed an easy Achilles tendon suture and postoperative ankle fixation model in a mouse. Right Achilles tendons were incised and 10-0 nylons were passed through the proximal and distal ends using a modified Kessler method. Subsequently, the right ankle was immobilized in a plantarflexed position with novel splints, which were made from readily available extension tubes. Restriction of the tendon using handmade splints reduced swelling, as opposed to fixating with the usual plaster of Paris. Using this method, the usage of the right Achilles tendons began on postoperative days 13.5 ± 4.6, which indicated healing within two weeks. Therefore our simple short-term murine Achilles tendon suture procedure is useful for studying immediate tendon repair mechanisms in various models, including genetically-modified mice. PMID:26678297

  11. Collagen fibril biosynthesis in tendon: a review and recent insights.

    PubMed

    Canty, E G; Kadler, K E

    2002-12-01

    The development and evolution of multicellular animals relies on the ability of certain cell types to synthesise an extracellular matrix (ECM) comprising very long collagen fibrils that are arranged in very ordered 3-dimensional scaffolds. Tendon is a good example of a highly ordered ECM, in which tens of millions of collagen fibrils, each hundreds of microns long, are synthesised parallel to the tendon long axis. This review highlights recent discoveries showing that the assembly of collagen fibrils in tendon is hierarchical, and involves the formation of fairly short "collagen early fibrils" that are the fusion precursors of the very long fibrils that occur in mature tendon. PMID:12485687

  12. Nanoparticles for Tendon Healing and Regeneration: Literature Review.

    PubMed

    Parchi, Paolo D; Vittorio, Orazio; Andreani, Lorenzo; Battistini, Pietro; Piolanti, Nicola; Marchetti, Stefano; Poggetti, Andrea; Lisanti, Michele

    2016-01-01

    Tendon injuries are commonly met in the emergency department. Unfortunately, tendon tissue has limited regeneration potential and usually the consequent formation of scar tissue causes inferior mechanical properties. Nanoparticles could be used in different way to improve tendon healing and regeneration, ranging from scaffolds manufacturing (increasing the strength and endurance or anti-adhesions, anti-microbial, and anti-inflammatory properties) to gene therapy. This paper aims to summarize the most relevant studies showing the potential application of nanoparticles for tendon tissue regeneration. PMID:27597828

  13. Multiple variations of the tendons of the anatomical snuffbox

    PubMed Central

    Thwin, San San; Zaini, Fazlin; Than, Myo

    2014-01-01

    INTRODUCTION Multiple tendons of the abductor pollicis longus (APL) in the anatomical snuffbox of the wrist can lead to the development of de Quervain's syndrome, which is caused by stenosing tenosynovitis. A cadaveric study was performed to establish the variations present in the tendons of the anatomical snuffbox in a Malaysian population, in the hope that this knowledge would aid clinical investigation and surgical treatment of de Quervain's tenosynovitis. METHODS Routine dissection of ten upper limbs was performed to determine the variations in the tendons of the anatomical snuffbox of the wrist. RESULTS In all the dissected upper limbs, the APL tendon of the first extensor compartment was found to have several (3–14) tendon slips. The insertion of the APL tendon slips in all upper limbs were at the base of the first metacarpal bone, trapezium and fascia of the opponens pollicis muscle; however, in seven specimens, they were also found to be attached to the fleshy belly of the abductor pollicis brevis muscle. In two specimens, double tendons of the extensor pollicis longus located in the third extensor compartment were inserted into the capsule of the proximal interphalangeal joints before being joined to the extensor expansion. In two other specimens, the first extensor compartment had two osseofibrous tunnels divided by a septum that separated the APL tendon from the extensor pollicis brevis tendon. CONCLUSION Multiple variations were found in the anatomical snuffbox region of the dissected upper limbs. Knowledge of these variations would be useful in interventional radiology and orthopaedic surgery. PMID:24452976

  14. Inflammation activation and resolution in human tendon disease

    PubMed Central

    Dakin, Stephanie G; Martinez, Fernando O; Yapp, Clarence; Wells, Graham; Oppermann, Udo; Dean, Benjamin JF; Smith, Richard DJ; Wheway, Kim; Watkins, Bridget; Roche, Lucy; Carr, Andrew J

    2016-01-01

    Improved understanding of the role of inflammation in tendon disease is required to facilitate therapeutic target discovery. We studied supraspinatus tendons from patients experiencing pain before and after surgical subacromial decompression treatment. Tendons were classified as having early, intermediate or advanced disease and inflammation was characterized through activation of pathways mediated by Interferon, NF-κB, glucocorticoid receptor and STAT-6. Inflammation signatures revealed expression of genes and proteins induced by Interferon and NF-κB in early stage disease and genes and proteins induced by STAT-6 and glucocorticoid receptor activation in advanced stage disease. The pro-resolving proteins FPR2/ALX and ChemR23 were increased in early stage disease compared to intermediate-advanced stage disease. Patients who were pain-free post-treatment had tendons with increased expression of CD206 and ALOX15 mRNA compared to tendons from patients who continued to experience pain post-treatment, suggesting that these genes and their pathways may moderate tendon pain. Stromal cells from diseased tendons cultured in vitro showed increased expression of NF-κB and Interferon target genes after treatment with lipopolysaccharide or IFNγ compared to stromal cells derived from healthy tendons. We identified 15-epi Lipoxin A4, a stable lipoxin metabolite derived from aspirin treatment, as potentially beneficial in the resolution of tendon inflammation. PMID:26511510

  15. Engineering Tendon: Scaffolds, Bioreactors, and Models of Regeneration

    PubMed Central

    Youngstrom, Daniel W.; Barrett, Jennifer G.

    2016-01-01

    Tendons bridge muscle and bone, translating forces to the skeleton and increasing the safety and efficiency of locomotion. When tendons fail or degenerate, there are no effective pharmacological interventions. The lack of available options to treat damaged tendons has created a need to better understand and improve the repair process, particularly when suitable autologous donor tissue is unavailable for transplantation. Cells within tendon dynamically react to loading conditions and undergo phenotypic changes in response to mechanobiological stimuli. Tenocytes respond to ultrastructural topography and mechanical deformation via a complex set of behaviors involving force-sensitive membrane receptor activity, changes in cytoskeletal contractility, and transcriptional regulation. Effective ex vivo model systems are needed to emulate the native environment of a tissue and to translate cell-matrix forces with high fidelity. While early bioreactor designs have greatly expanded our knowledge of mechanotransduction, traditional scaffolds do not fully model the topography, composition, and mechanical properties of native tendon. Decellularized tendon is an ideal scaffold for cultivating replacement tissue and modeling tendon regeneration. Decellularized tendon scaffolds (DTS) possess high clinical relevance, faithfully translate forces to the cellular scale, and have bulk material properties that match natural tissue. This review summarizes progress in tendon tissue engineering, with a focus on DTS and bioreactor systems. PMID:26839559

  16. Engineering Tendon: Scaffolds, Bioreactors, and Models of Regeneration.

    PubMed

    Youngstrom, Daniel W; Barrett, Jennifer G

    2016-01-01

    Tendons bridge muscle and bone, translating forces to the skeleton and increasing the safety and efficiency of locomotion. When tendons fail or degenerate, there are no effective pharmacological interventions. The lack of available options to treat damaged tendons has created a need to better understand and improve the repair process, particularly when suitable autologous donor tissue is unavailable for transplantation. Cells within tendon dynamically react to loading conditions and undergo phenotypic changes in response to mechanobiological stimuli. Tenocytes respond to ultrastructural topography and mechanical deformation via a complex set of behaviors involving force-sensitive membrane receptor activity, changes in cytoskeletal contractility, and transcriptional regulation. Effective ex vivo model systems are needed to emulate the native environment of a tissue and to translate cell-matrix forces with high fidelity. While early bioreactor designs have greatly expanded our knowledge of mechanotransduction, traditional scaffolds do not fully model the topography, composition, and mechanical properties of native tendon. Decellularized tendon is an ideal scaffold for cultivating replacement tissue and modeling tendon regeneration. Decellularized tendon scaffolds (DTS) possess high clinical relevance, faithfully translate forces to the cellular scale, and have bulk material properties that match natural tissue. This review summarizes progress in tendon tissue engineering, with a focus on DTS and bioreactor systems. PMID:26839559

  17. A non-invasive method of tendon force measurement.

    PubMed

    Pourcelot, Philippe; Defontaine, Marielle; Ravary, Bérangère; Lemâtre, Mickaël; Crevier-Denoix, Nathalie

    2005-10-01

    The ability to measure the forces exerted in vivo on tendons and, consequently, the forces produced by muscles on tendons, offers a unique opportunity to investigate questions in disciplines as varied as physiology, biomechanics, orthopaedics and neuroscience. Until now, tendon loads could be assessed directly only by means of invasive sensors implanted within or attached to these collagenous structures. This study shows that the forces acting on tendons can be measured, in a non-invasive way, from the analysis of the propagation of an acoustic wave. Using the equine superficial digital flexor tendon as a model, it is demonstrated that the velocity of an ultrasonic wave propagating along the main axis of a tendon increases with the force applied to this tendon. Furthermore, we show that this velocity measurement can be performed even in the presence of skin overlying the tendon. To validate this measurement technique in vivo, the ultrasonic velocity plots obtained in the Achilles tendon at the walk were compared to the loads plots reported by other authors using invasive transducers. PMID:16084214

  18. The atypical homeodomain transcription factor Mohawk controls tendon morphogenesis.

    PubMed

    Liu, Wenjin; Watson, Spencer S; Lan, Yu; Keene, Douglas R; Ovitt, Catherine E; Liu, Han; Schweitzer, Ronen; Jiang, Rulang

    2010-10-01

    The Mohawk homeobox (Mkx) gene encodes a new atypical homeodomain-containing protein with transcriptional repressor activity. Mkx mRNA exhibited dynamic expression patterns during development of the palate, somite, kidney, and testis, suggesting that it may be an important regulator of multiple developmental processes. To investigate the roles of Mkx in organogenesis, we generated mice carrying a null mutation in this gene. Mkx(-/-) mice survive postnatally and exhibit a unique wavy-tail phenotype. Close examination revealed that the mutant mice had smaller tendons than wild-type littermates and that the rapid postnatal growth of collagen fibrils in tendons was disrupted in Mkx(-/-) mice. Defects in tendon development were detected in the mutant mouse embryos as early as embryonic day 16.5 (E16.5). Although collagen fibril assembly initially appeared normal, the tendons of Mkx(-/-) embryos expressed significantly reduced amounts of collagen I, fibromodulin, and tenomodulin in comparison with control littermates. We found that Mkx mRNA was strongly expressed in differentiating tendon cells during embryogenesis and in the tendon sheath cells in postnatal stages. In addition to defects in tendon collagen fibrillogenesis, Mkx(-/-) mutant mice exhibited abnormal tendon sheaths. These results identify Mkx as an important regulator of tendon development. PMID:20696843

  19. Tendon synovial cells secrete fibronectin in vivo and in vitro

    SciTech Connect

    Banes, A.J.; Link, G.W.; Bevin, A.G.; Peterson, H.D.; Gillespie, Y.; Bynum, D.; Watts, S.; Dahners, L.

    1988-01-01

    The chemistry and cell biology of the tendon have been largely overlooked due to the emphasis on collagen, the principle structural component of the tendon. The tendon must not only transmit the force of muscle contraction to bone to effect movement, but it must also glide simultaneously over extratendonous tissues. Fibronectin is classified as a cell attachment molecule that induces cell spreading and adhesion to substratum. The external surface of intact avian flexor tendon stained positively with antibody to cellular fibronectin. However, if the surface synovial cells were first removed with collagenase, no positive reaction with antifibronectin antibody was detected. Analysis of immunologically stained frozen sections of tendon also revealed fibronectin at the tendon synovium, but little was associated with cells internal in tendon. The staining pattern with isolated, cultured synovial cells and fibroblasts from the tendon interior substantiated the histological observations. Analysis of polyacrylamide gel profiles of /sup 35/S-methionine-labeled proteins synthesized by synovial cells and internal fibroblasts indicated that fibronectin was synthesized principally by synovial cells. Fibronectin at the tendon surface may play a role in cell attachment to prevent cell removal by the friction of gliding. Alternatively, fibronectin, with its binding sites for hyaluronic acid and collagen, may act as a complex for boundary lubrication.

  20. Nanoparticles for Tendon Healing and Regeneration: Literature Review

    PubMed Central

    Parchi, Paolo D.; Vittorio, Orazio; Andreani, Lorenzo; Battistini, Pietro; Piolanti, Nicola; Marchetti, Stefano; Poggetti, Andrea; Lisanti, Michele

    2016-01-01

    Tendon injuries are commonly met in the emergency department. Unfortunately, tendon tissue has limited regeneration potential and usually the consequent formation of scar tissue causes inferior mechanical properties. Nanoparticles could be used in different way to improve tendon healing and regeneration, ranging from scaffolds manufacturing (increasing the strength and endurance or anti-adhesions, anti-microbial, and anti-inflammatory properties) to gene therapy. This paper aims to summarize the most relevant studies showing the potential application of nanoparticles for tendon tissue regeneration. PMID:27597828

  1. Giant Cell Tumor of the Peroneus Brevis Tendon Sheath

    PubMed Central

    Ch, Li; TH, Lui

    2015-01-01

    Introduction: Giant cell tumor of the tendon sheath is most commonly found in the flexor aspect of hand and wrist and is rare in the foot and ankle. Case report: A 49-year-old lady noticed a right lateral foot mass for 10 years. Magnetic resonance imaging suggested that the mass is originated from the peroneal tendons. The mass was excised and intra-operative findings showed that the tumor came from the peroneus brevis tendon sheath. Histological study confirmed the diagnosis of giant cell tumor. Conclusion: Giant cell tumor, although rare, should be one of the differential diagnoses of tendon sheath tumor of the foot and ankle. PMID:27299104

  2. Biological Augmentation of Flexor Tendon Repair: A Challenging Cellular Landscape.

    PubMed

    Loiselle, Alayna E; Kelly, Meghan; Hammert, Warren C

    2016-01-01

    Advances in surgical technique and rehabilitation have transformed zone II flexor tendon injuries from an inoperable no-man's land to a standard surgical procedure. Despite these advances, many patients develop substantial range of motion-limiting adhesions after primary flexor tendon repair. These suboptimal outcomes may benefit from biologic augmentation or intervention during the flexor tendon healing process. However, there is no consensus biological approach to promote satisfactory flexor tendon healing; we propose that insufficient understanding of the complex cellular milieu in the healing tendon has hindered the development of successful therapies. This article reviews recent advances in our understanding of the cellular components of flexor tendon healing and adhesion formation, including resident tendon cells, synovial sheath, macrophages, and bone marrow-derived cells. In addition, it examines molecular approaches that have been used in translational animal models to improve flexor tendon healing and gliding function, with a specific focus on progress made using murine models of healing. This information highlights the importance of understanding and potentially exploiting the heterogeneity of the cellular environment during flexor tendon healing, to define rational therapeutic approaches to improve healing outcomes. PMID:26652792

  3. Outcome following addition of peroneus brevis tendon transfer to treatment of acquired posterior tibial tendon insufficiency.

    PubMed

    Song, S J; Deland, J T

    2001-04-01

    The flexor digitorum longus, the tendon most often used for transfer in posterior tibial tendon insufficiency, is one-half to one-third the size of the posterior tibial tendon. Occasionally it may be particularly small or may have been previously used for transfer. In these cases, the senior author has felt that the addition of a transfer of the Peroneus Brevis (PBr) tendon may be helpful in maintaining sufficient tendon and muscle mass to rebalance the foot. Thirteen patients who underwent this procedure were retrospectively identified and matched by age and length of follow-up to patients who underwent a more standard tendon transfer operation minus the addition of the PBr transfer. Pain and functional status were then assessed by the American Orthopaedic Foot and Ankle Society's ankle/hindfoot rating scale. Each patient was tested by an independent physical therapist to evaluate inversion and eversion strength. The mean duration of follow-up was 20.6 months (12 to 34 months). The average AOFAS score of the PBr group was 75.8 compared to 71.5 for the standard control group. There was no significant difference between the groups when inversion or eversion strengths were compared. Inversion strength and eversion strength was rated good or excellent (4 or 5) in 12 out of 13 of the PBr transfer group patients. No major complications were encountered in either group. Although it does not increase inversion strength, a PBr transfer can be used to augment a small FDL without causing significant eversion weakness. This can be useful when the FDL is particularly small or in revision surgery. PMID:11354442

  4. Biology of cancellous bone grafts.

    PubMed

    Heiple, K G; Goldberg, V M; Powell, A E; Bos, G D; Zika, J M

    1987-04-01

    Despite 30 years of experimental bone grafting research, the fresh cancellous bone graft remains the most osteogenic and reliable bone grafting material. Recent experimental data suggest that modification of the graft-host interaction by antigen matching or immune manipulation may allow increasingly successful use of allografts. PMID:3550570

  5. A composite graft material containing bone particles and collagen in osteoinduction in mouse.

    PubMed

    Tsai, Chung-Hung; Chou, Ming-Yung; Jonas, Mecrehild; Tien, Yung-Tico; Chi, Emily Y

    2002-01-01

    Demineralized allogenic bone matrices (DABM) and demineralized freeze-dried bone allograft (DFDBA) have been successfully used as bone-graft materials in the treatment of acquired and congenital cranio-maxillofacial defects and in some orthopedic surgery. However, these bone-graft "powders" have many shortcomings. For example, placement of particulate graft material in a hemorrhaging site can result in inadequacies or inaccurate attachment as well as loss of the graft materials. To minimize the inadequacies of powderlike graft materials, xenogenic collagen isolated from human tendon, skin, or bone was added to the bone-graft particles to form a composite spongelike implant. This material is commercially available and consists of 60% collagen and 40% DFDBA (DynaGraft, GenSci Co., Irvine, CA). The goal of this study was to evaluate the characteristics of composite graft implants in the mineralization process in an animal model in comparison with DFDBA powder and pure collagen. Seventy-two Swiss Webster mice were divided into three groups: an experimental group implanted with DynaGraft, two comparison groups implanted with either DFDBA or collagen only. All the graft materials were surgically implanted and inserted into the left thigh muscle. Mice were humanely killed at 1, 2, 3, 4, 6, 8, and 12 weeks. Then the muscle tissues in the vicinity of the implants were excised and processed for histology. Paraffin sections were stained with hematoxylin and eosin (H&E), the Von Kossa method, and Masson's trichrome. Some selected specimens were processed for transmission electron microscopic observation. After 1 week of implantation, the DynaGraft group showed calcium deposition on the collagen material and on the periphery of the DFDBA particles. Increased calcification and bone-forming cells were observed at 4-6 weeks. After 8 weeks, the implant formed a calcified nodule and only heavily mineralized connective tissue was observed at the implanted site. The group implanted

  6. Simultaneous traumatic rupture of the patellar tendon and the contralateral quadriceps tendon in a healthy individual

    PubMed Central

    Kumar, S; Rachakatla, N; Kerin, C; Kumar, R

    2010-01-01

    A simultaneous traumatic complete rupture of the patellar tendon and the contralateral quadriceps tendon is reported to occur in patients with renal failure and other inflammatory diseases, but is extremely rare in a healthy individual because of the different contributory factors and mechanisms of injury. We present a rare case report of such a combination of injuries in a 48-year-old healthy man. To our knowledge only three such cases have been reported in the English literature. This is an unusual combination and hence there is potential for missed diagnosis leading to suboptimal treatment. PMID:22791858

  7. Tendon Progenitor Cells in Injured Tendons Have Strong Chondrogenic Potential: The CD105-Negative Subpopulation Induces Chondrogenic Degeneration

    PubMed Central

    Asai, Shuji; Otsuru, Satoru; Candela, Maria Elena; Cantley, Leslie; Uchibe, Kenta; Hofmann, Ted J.; Zhang, Kairui; Wapner, Keith L.; Soslowsky, Louis J; Horwitz, Edwin M.; Enomoto-Iwamoto, Motomi

    2014-01-01

    To study the cellular mechanism of the tendon repair process, we used a mouse Achilles tendon injury model to focus on the cells recruited to the injured site. The cells isolated from injured tendon 1 week after the surgery and uninjured tendons contained the connective tissue progenitor populations as determined by colony-forming capacity, cell surface markers and multipotency. When the injured tendon-derived progenitor cells (inTPCs) were transplanted into injured Achilles tendons, they were not only integrated in the regenerating area expressing tenogenic phenotype but also trans-differentiated into chondrogenic cells in the degenerative lesion that underwent ectopic endochondral ossification. Surprisingly, the micromass culture of the inTPCs rapidly underwent chondrogenic differentiation even in the absence of exogenous BMPs or TGFβs. The cells isolated from human ruptured tendon tissues also showed connective tissue progenitor properties and exhibited stronger chondrogenic ability than bone marrow stromal cells. The mouse inTPCs contained two subpopulations one positive and one negative for CD105, a co-receptor of the TGFβ superfamily. The CD105-negative cells showed superior chondrogenic potential in vitro and induced larger chondroid degenerative lesions in mice as compared to the CD105-positive cells. These findings indicate that tendon progenitor cells are recruited to the injured site of tendons and have a strong chondrogenic potential and that the CD105-negative population of these cells would be the cause for chondroid degeneration in injured tendons. The newly identified cells recruited to the injured tendon may provide novel targets to develop therapeutic strategies to facilitate tendon repair. PMID:25220576

  8. The promoting effect of pentadecapeptide BPC 157 on tendon healing involves tendon outgrowth, cell survival, and cell migration.

    PubMed

    Chang, Chung-Hsun; Tsai, Wen-Chung; Lin, Miao-Sui; Hsu, Ya-Hui; Pang, Jong-Hwei Su

    2011-03-01

    Pentadecapeptide BPC 157, composed of 15 amino acids, is a partial sequence of body protection compound (BPC) that is discovered in and isolated from human gastric juice. Experimentally it has been demonstrated to accelerate the healing of many different wounds, including transected rat Achilles tendon. This study was designed to investigate the potential mechanism of BPC 157 to enhance healing of injured tendon. The outgrowth of tendon fibroblasts from tendon explants cultured with or without BPC 157 was examined. Results showed that BPC 157 significantly accelerated the outgrowth of tendon explants. Cell proliferation of cultured tendon fibroblasts derived from rat Achilles tendon was not directly affected by BPC 157 as evaluated by MTT assay. However, the survival of BPC 157-treated cells was significantly increased under the H(2)O(2) stress. BPC 157 markedly increased the in vitro migration of tendon fibroblasts in a dose-dependent manner as revealed by transwell filter migration assay. BPC 157 also dose dependently accelerated the spreading of tendon fibroblasts on culture dishes. The F-actin formation as detected by FITC-phalloidin staining was induced in BPC 157-treated fibroblasts. The protein expression and activation of FAK and paxillin were determined by Western blot analysis, and the phosphorylation levels of both FAK and paxillin were dose dependently increased by BPC 157 while the total amounts of protein was unaltered. In conclusion, BPC 157 promotes the ex vivo outgrowth of tendon fibroblasts from tendon explants, cell survival under stress, and the in vitro migration of tendon fibroblasts, which is likely mediated by the activation of the FAK-paxillin pathway. PMID:21030672

  9. Simultaneous rupture of the quadriceps tendon with contralateral rupture of the patellar tendon in an otherwise healthy athlete.

    PubMed Central

    Munshi, N I; Mbubaegbu, C E

    1996-01-01

    A case of a healthy athlete with simultaneous rupture of quadriceps tendon and rupture of the contralateral patella tendon is reported. Both tendons rupturing in the same patient is rare and this is the first reported case in a previously healthy person. Different mechanisms are implicated in the different ruptures. The rarity is because the simultaneous presence of contributory factors for either injury in the same person is uncommon. Images Fig. 2 PMID:8799608

  10. Clinical and Morphological Changes Following 2 Rehabilitation Programs for Acute Hamstring Strain Injuries: A Randomized Clinical Trial

    PubMed Central

    SILDER, AMY; SHERRY, MARC A.; SANFILIPPO, JENNIFER; TUITE, MICHAEL J.; HETZEL, SCOTT J.; HEIDERSCHEIT, BRYAN C.

    2013-01-01

    STUDY DESIGN Randomized, double-blind, parallel-group clinical trial. OBJECTIVES To assess differences between a progressive agility and trunk stabilization rehabilitation program and a progressive running and eccentric strengthening rehabilitation program in recovery characteristics following an acute hamstring injury, as measured via physical examination and magnetic resonance imaging (MRI). BACKGROUND Determining the type of rehabilitation program that most effectively promotes muscle and functional recovery is essential to minimize reinjury risk and to optimize athlete performance. METHODS Individuals who sustained a recent hamstring strain injury were randomly assigned to 1 of 2 rehabilitation programs: (1) progressive agility and trunk stabilization or (2) progressive running and eccentric strengthening. MRI and physical examinations were conducted before and after completion of rehabilitation. RESULTS Thirty-one subjects were enrolled, 29 began rehabilitation, and 25 completed rehabilitation. There were few differences in clinical or morphological outcome measures between rehabilitation groups across time, and reinjury rates were low for both rehabilitation groups after return to sport (4 of 29 subjects had reinjuries). Greater craniocaudal length of injury, as measured on MRI before the start of rehabilitation, was positively correlated with longer return-to-sport time. At the time of return to sport, although all subjects showed a near-complete resolution of pain and return of muscle strength, no subject showed complete resolution of injury as assessed on MRI. CONCLUSION The 2 rehabilitation programs employed in this study yielded similar results with respect to hamstring muscle recovery and function at the time of return to sport. Evidence of continuing muscular healing is present after completion of rehabilitation, despite the appearance of normal physical strength and function on clinical examination. LEVEL OF EVIDENCE Therapy, level 1b–. J Orthop

  11. EVALUATION OF THE RESULTS OF ARTHROSCOPIC ACL RECONSTRUCTION WITH AUTOGENOUS FLEXOR TENDONS

    PubMed Central

    Almeida, Alexandre; Valin, Múrcio Rangel; Ferreira, Ramon; Roveda, Gilberto; de Almeida, Nayvaldo Couto; Agostini, Ana Paula

    2015-01-01

    Objective: To evaluate the results from reconstruction of the anterior cruciate ligament (ACL) using with flexor tendon autografts from the thigh, with analysis on data relating to sex, body mass index (BMI) and associations with lower limb fracture. Methods: A group of 265 patients who underwent knee arthroscopy for the purposes of ACL reconstruction using an ipsilateral graft from the flexor tendon of the thigh between July 6, 2000, and November 19, 2007, were evaluated. Results: One hundred and seventy-six patients were evaluated over a mean period of 34.95 ± 18.8 months (median: 31 months) (IQR: 20-48 months). The minimum evaluation period was 12 months and the maximum was 87 months. One hundred and thirty-eight patients (78.4%) had excellent results, 22 (12.5%) had good results, eight (4.5%) had fair results and eight (4.5%) had poor results. Higher incidence of good and excellent results for the following categories was not considered to be significant: males (p = 0.128), patients with BMI < 25 (p = 0.848), or patients with ACL injuries unrelated to an initial traumatic episode of lower-limb fracture (p = 0.656). Conclusion: The ACL reconstruction technique using tendon autografts from the thigh showed good and excellent results for 91.4% of the sample. Male patients seemed to present a greater tendency towards good and excellent results. No statistically significant difference was found when the results were analyzed in relation to BMI or associations with initial traumatic fracture episodes in the lower limbs. PMID:27022571

  12. The interfascicular matrix enables fascicle sliding and recovery in tendon, and behaves more elastically in energy storing tendons

    PubMed Central

    Thorpe, Chavaunne T.; Godinho, Marta S.C.; Riley, Graham P.; Birch, Helen L.; Clegg, Peter D.; Screen, Hazel R.C.

    2015-01-01

    While the predominant function of all tendons is to transfer force from muscle to bone and position the limbs, some tendons additionally function as energy stores, reducing the cost of locomotion. Energy storing tendons experience extremely high strains and need to be able to recoil efficiently for maximum energy storage and return. In the equine forelimb, the energy storing superficial digital flexor tendon (SDFT) has much higher failure strains than the positional common digital extensor tendon (CDET). However, we have previously shown that this is not due to differences in the properties of the SDFT and CDET fascicles (the largest tendon subunits). Instead, there is a greater capacity for interfascicular sliding in the SDFT which facilitates the greater extensions in this particular tendon (Thorpe et al., 2012). In the current study, we exposed fascicles and interfascicular matrix (IFM) from the SDFT and CDET to cyclic loading followed by a test to failure. The results show that IFM mechanical behaviour is not a result of irreversible deformation, but the IFM is able to withstand cyclic loading, and is more elastic in the SDFT than in the CDET. We also assessed the effect of ageing on IFM properties, demonstrating that the IFM is less able to resist repetitive loading as it ages, becoming stiffer with increasing age in the SDFT. These results provide further indications that the IFM is important for efficient function in energy storing tendons, and age-related alterations to the IFM may compromise function and predispose older tendons to injury. PMID:25958330

  13. In vivo tendon forces correlate with activity level and remain bounded: evidence in a rabbit flexor tendon model.

    PubMed

    Malaviya, P; Butler, D L; Korvick, D L; Proch, F S

    1998-11-01

    While some tendons and ligaments in the lower extremity develop peak forces proportional to the intensity of activity (Komi 1990; Komi et al., 1992; Korvick et al., 1996), others maintain a steady force regardless of activity level (Herzog et al., 1993; Prilutsky et al., 1994). Investigators (Biewener et al., 1988; Korvick et al., 1996) have also shown that peak knee and ankle tendon forces approach one-quarter to one-third of ultimate or failure force values. In the rabbit flexor digitorum profundus (FDP) tendon model we tested several hypotheses, chiefly that peak in vivo forces not only increase with increasing activity but do not exceed one-third of their ultimate or failure values. The FDP tendon was instrumented in three animals, and each rabbit subjected to an experimental design involving three activity levels. Peak tensile forces and rates of rise and fall in tendon force increased significantly with increasing activity (p < 0.01). Further, the tendon maintained a non-zero force level throughout all trials. For the most vigorous activity, inclined hopping, tensile forces and stresses were, on average, within 30% of the tendon's ultimate force and stress values, respectively. Such in vivo measurements in different tendon systems should help investigators better understand the recruitment and contribution of important muscle-tendon units to joint stability and gait. PMID:9880061

  14. The interfascicular matrix enables fascicle sliding and recovery in tendon, and behaves more elastically in energy storing tendons.

    PubMed

    Thorpe, Chavaunne T; Godinho, Marta S C; Riley, Graham P; Birch, Helen L; Clegg, Peter D; Screen, Hazel R C

    2015-12-01

    While the predominant function of all tendons is to transfer force from muscle to bone and position the limbs, some tendons additionally function as energy stores, reducing the cost of locomotion. Energy storing tendons experience extremely high strains and need to be able to recoil efficiently for maximum energy storage and return. In the equine forelimb, the energy storing superficial digital flexor tendon (SDFT) has much higher failure strains than the positional common digital extensor tendon (CDET). However, we have previously shown that this is not due to differences in the properties of the SDFT and CDET fascicles (the largest tendon subunits). Instead, there is a greater capacity for interfascicular sliding in the SDFT which facilitates the greater extensions in this particular tendon (Thorpe et al., 2012). In the current study, we exposed fascicles and interfascicular matrix (IFM) from the SDFT and CDET to cyclic loading followed by a test to failure. The results show that IFM mechanical behaviour is not a result of irreversible deformation, but the IFM is able to withstand cyclic loading, and is more elastic in the SDFT than in the CDET. We also assessed the effect of ageing on IFM properties, demonstrating that the IFM is less able to resist repetitive loading as it ages, becoming stiffer with increasing age in the SDFT. These results provide further indications that the IFM is important for efficient function in energy storing tendons, and age-related alterations to the IFM may compromise function and predispose older tendons to injury. PMID:25958330

  15. Field monitoring of sprinting power-force-velocity profile before, during and after hamstring injury: two case reports.

    PubMed

    Mendiguchia, J; Edouard, P; Samozino, P; Brughelli, M; Cross, M; Ross, A; Gill, N; Morin, J B

    2016-01-01

    Very little is currently known about the effects of acute hamstring injury on over-ground sprinting mechanics. The aim of this research was to describe changes in power-force-velocity properties of sprinting in two injury case studies related to hamstring strain management: Case 1: during a repeated sprint task (10 sprints of 40 m) when an injury occurred (5th sprint) in a professional rugby player; and Case 2: prior to (8 days) and after (33 days) an acute hamstring injury in a professional soccer player. A sports radar system was used to measure instantaneous velocity-time data, from which individual mechanical profiles were derived using a recently validated method based on a macroscopic biomechanical model. Variables of interest included: maximum theoretical velocity (V0) and horizontal force (F(H0)), slope of the force-velocity (F-v) relationship, maximal power, and split times over 5 and 20 m. For Case 1, during the injury sprint (sprint 5), there was a clear change in the F-v profile with a 14% greater value of F(H0) (7.6-8.7 N/kg) and a 6% decrease in V0 (10.1 to 9.5 m/s). For Case 2, at return to sport, the F-v profile clearly changed with a 20.5% lower value of F(H0) (8.3 vs. 6.6 N/kg) and no change in V0. The results suggest that the capability to produce horizontal force at low speed (F(H0)) (i.e. first metres of the acceleration phase) is altered both before and after return to sport from a hamstring injury in these two elite athletes with little or no change of maximal velocity capabilities (V0), as evidenced in on-field conditions. Practitioners should consider regularly monitoring horizontal force production during sprint running both from a performance and injury prevention perspective. PMID:26648237

  16. Measurement of stress strain and vibrational properties of tendons

    NASA Astrophysics Data System (ADS)

    Revel, Gian Marco; Scalise, Alessandro; Scalise, Lorenzo

    2003-08-01

    The authors present a new non-intrusive experimental procedure based on laser techniques for the measurement of mechanical properties of tendons. The procedure is based on the measurement of the first resonance frequency of the tendon by laser Doppler vibrometry during in vitro tensile experiments, with the final aim of establishing a measurement procedure to perform the mechanical characterization of tendons by extracting parameters such as the resonance frequency, also achievable during in vivo investigation. The experimental procedure is reported, taking into account the need to simulate the physiological conditions of the Achilles tendon, and the measurement technique used for the non-invasive determination of tendon cross-sectional area during tensile vibration tests at different load levels is described. The test procedure is based on a tensile machine, which measures longitudinal tendons undergoing controlled load conditions. Cross-sectional area is measured using a new non-contact procedure for the measurement of tendon perimeter (repeatability of 99% and accuracy of 2%). For each loading condition, vibration resonance frequency and damping, cross-sectional area and tensile force are measured, allowing thus a mechanical characterization of the tendon. Tendon stress-strain curves are reported. Stress-strain curves have been correlated to the first vibration resonance frequency and damping of the tendon measured using a single-point laser Doppler vibrometer. Moreover, experimental results have been compared with a theoretical model of a vibrating cord showing discrepancies. In vitro tests are reported, demonstrating the validity of the method for the comparison of different aged rabbit tendons.

  17. The integrated function of muscles and tendons during locomotion.

    PubMed

    Roberts, Thomas J

    2002-12-01

    The mechanical roles of tendon and muscle contractile elements during locomotion are often considered independently, but functionally they are tightly integrated. Tendons can enhance muscle performance for a wide range of locomotor activities because muscle-tendon units shorten and lengthen at velocities that would be mechanically unfavorable for muscle fibers functioning alone. During activities that require little net mechanical power output, such as steady-speed running, tendons reduce muscular work by storing and recovering cyclic changes in the mechanical energy of the body. Tendon stretch and recoil not only reduces muscular work, but also allows muscle fibers to operate nearly isometrically, where, due to the force-velocity relation, skeletal muscle fibers develop high forces. Elastic energy storage and recovery in tendons may also provide a key mechanism to enable individual muscles to alter their mechanical function, from isometric force-producers during steady speed running to actively shortening power-producers during high-power activities like acceleration or uphill running. Evidence from studies of muscle contraction and limb dynamics in turkeys suggests that during running accelerations work is transferred directly from muscle to tendon as tendon stretch early in the step is powered by muscle shortening. The energy stored in the tendon is later released to help power the increase in energy of the body. These tendon length changes redistribute muscle power, enabling contractile elements to shorten at relatively constant velocities and power outputs, independent of the pattern of flexion/extension at a joint. Tendon elastic energy storage and recovery extends the functional range of muscles by uncoupling the pattern of muscle fiber shortening from the pattern of movement of the body. PMID:12485693

  18. The development of zebrafish tendon and ligament progenitors.

    PubMed

    Chen, Jessica W; Galloway, Jenna L

    2014-05-01

    Despite the importance of tendons and ligaments for transmitting movement and providing stability to the musculoskeletal system, their development is considerably less well understood than that of the tissues they serve to connect. Zebrafish have been widely used to address questions in muscle and skeletal development, yet few studies describe their tendon and ligament tissues. We have analyzed in zebrafish the expression of several genes known to be enriched in mammalian tendons and ligaments, including scleraxis (scx), collagen 1a2 (col1a2) and tenomodulin (tnmd), or in the tendon-like myosepta of the zebrafish (xirp2a). Co-expression studies with muscle and cartilage markers demonstrate the presence of scxa, col1a2 and tnmd at sites between the developing muscle and cartilage, and xirp2a at the myotendinous junctions. We determined that the zebrafish craniofacial tendon and ligament progenitors are neural crest derived, as in mammals. Cranial and fin tendon progenitors can be induced in the absence of differentiated muscle or cartilage, although neighboring muscle and cartilage are required for tendon cell maintenance and organization, respectively. By contrast, myoseptal scxa expression requires muscle for its initiation. Together, these data suggest a conserved role for muscle in tendon development. Based on the similarities in gene expression, morphology, collagen ultrastructural arrangement and developmental regulation with that of mammalian tendons, we conclude that the zebrafish tendon populations are homologous to their force-transmitting counterparts in higher vertebrates. Within this context, the zebrafish model can be used to provide new avenues for studying tendon biology in a vertebrate genetic system. PMID:24803652

  19. Proximal Tibial Bone Graft

    MedlinePlus

    ... Complications Potential problems after a PTBG include infection, fracture of the proximal tibia and pain related to the procedure. Frequently Asked Questions If proximal tibial bone graft is taken from my knee, will this prevent me from being able to ...

  20. Epidermal skin grafting.

    PubMed

    Herskovitz, Ingrid; Hughes, Olivia B; Macquhae, Flor; Rakosi, Adele; Kirsner, Robert

    2016-09-01

    Autologous skin grafts, such as full- and split-thickness, have long been part of the reconstructive ladder as an option to close skin defects. Although they are effective in providing coverage, they require the need for a trained surgeon, use of anaesthesia and operating room and creation of a wound at the donor site. These drawbacks can be overcome with the use of epidermal skin grafts (ESGs), which can be harvested without the use of anaesthesia in an office setting and with minimal to no scarring at the donor site. ESGs consist only of the epidermal layer and have emerged as an appealing alternative to other autologous grafts for the treatment of acute and chronic wounds. In this article, we provide an overview of epidermal grafting and its role in wound management. PMID:27547964

  1. Sizing of crimped Dacron grafts.

    PubMed

    Reid, J D; Sladen, J G

    1992-05-01

    The aim of this study was to correlate the stated size of Dacron grafts (Microvel) with their actual internal diameter and to compare this with measurements by ultrasound in the early postoperative period. Grafts of stated diameters of 7, 8, 9, and 10 mm were studied. Grafts were measured by graded probes and by measuring the width of the longitudinally opened graft and calculating the diameter. Each graft accepted a probe 1 mm larger than its stated size very easily and 2 mm greater when stretched. By open measurement, the grafts were 1.3 to 1.8 mm greater than their stated diameter without stretching. Twenty grafts were studied by duplex ultrasound for diameter and peak systolic velocity within 3 months of implantation. The grafts were 12% larger than their stated graft size. Some of the larger grafts showed low velocity and wall thrombus. We conclude that Microvel grafts are larger than their stated diameter. The same size discrepancy was seen in in vitro measurements of Vascutek (Dacron) grafts but not in polytetrafluoroethylene (Gortex) grafts. Since flow velocity is related to the diameter of the graft, this information should be useful when choosing the diameter of a prosthetic vascular graft. PMID:1533494

  2. [Zaidemberg's vascularized radial graft].

    PubMed

    Saint-Cast, Y

    2010-12-01

    In 1991, Carlos Zaidemberg described a new technique to repair scaphoid non-unions with a vascularized bone graft harvested from the radial styloid process. An anatomic study based on 30 dissections after colorized latex injection established the constancy of the radial styloid process's artery, while showing that its origin, course and length were subject to variations. In a retrospective series of 38 cases over a period of 10 years, the vascularized bone graft was indicated for: (1) scaphoid non-union with the presence of avascular changes of the proximal fragment (23 cases); (2) failed prior reconstruction with bone graft and internal fixation (nine cases); (3) degenerative styloid-scaphoid arthritis (three cases); (4) fracture on Preiser dystrophy (three cases). The five steps of the simplified operative technique without dissection of the vascular pedicle include: (1) longitudinal dorso-radial approach, identification of the periosteal portion of the radial styloid process artery; (2) incision of the first and second compartments, longitudinal arthrotomy under the second compartment; (3) styloidectomy and transversal resection of the scaphoid non-union and sclerotic bone; (4) elevation of the vascularized bone graft; (5) transversal and radial insertion of the vascularized bone graft, osteosynthesis by two or three K-wire touching the scaphoid's radial edge. Scaphoid union was obtained in 33 cases out of 38. The only postoperative complications were two transient radial paresthesia. The standardized surgical procedure using vascularized bone graft harvested from the radial styloid process provides an efficient scaphoid reconstruction. PMID:21087882

  3. Correlation Analysis of Potential Factors Influencing Graft Maturity After Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Li, Hong; Chen, Shuang; Tao, Hongyue; Li, Hongyun; Chen, Shiyi

    2014-01-01

    Background: Postoperatively, signal changes of the reconstructed anterior cruciate ligament (ACL) graft on magnetic resonance imaging (MRI) images commonly occurs, which may be a cause for concern. The signal intensity changes are usually expressed by signal/noise quotient (SNQ) value, representing graft maturity. To date, little is known about the factors influencing the SNQ value of the reconstructed ACL graft. Purpose: To evaluate ACL graft SNQ value and associated factors after ACL reconstruction. Study Design: Case series; Level of evidence, 4. Methods: Male patients who underwent ACL reconstruction using autograft or allograft tendon from September 2004 to September 2011 were randomly invited to take part in this investigation, including functional scores, physical examination, and MRI scan. The femoral side graft was fixed with Endobutton CL or Rigidfix pins, and the tibial side graft was fixed with a bio-intrafix. SNQ values of each graft were measured on MRI to represent graft maturity. Sagittal ACL angle, ACL–Blumensaat line angle, and medial and lateral posterior tibial slope (PTS) were measured using MRI 3-dimensional dual-echo steady-state images. Potential risk factors, including age, body mass index, postoperative time, Tegner activity scale (TAS), sagittal ACL angle, ACL–Blumensaat line angle, medial PTS, lateral PTS, and primary graft diameter, were tested for their association with the graft SNQ value by multivariate stepwise regression analysis. Results: A total of 104 male subjects (mean follow-up, 30.7 months) were examined, including 62 allograft and 42 autograft reconstructions. There was a significant association between graft SNQ and postoperative time (r = −0.431, P < .001), TAS (r = 0.295, P = .002), and ACL–Blumensaat line angle (r = −0.304, P = .002). Univariate regression analysis showed that TAS (β = 6.15, P < .001) positively correlated, postoperative time (β = −0.26, P < .001) negatively correlated, and ACL

  4. Achilles tendon suture deteriorates tendon capillary blood flow with sustained tissue oxygen saturation – an animal study

    PubMed Central

    Kraemer, Robert; Lorenzen, Johan; Rotter, Robert; Vogt, Peter M; Knobloch, Karsten

    2009-01-01

    Background Treatment of ruptured Achilles tendons currently constitutes of conservative early functional treatment or surgical treatment either by open or minimal invasive techniques. We hypothesize that an experimental Achilles tendon suture in an animal model significantly deteriorates Achilles tendon microcirculation immediately following suturing. Methods Fifteen Achilles tendons of eight male Wistar rats (275–325 g) were included. After preparation of the Achilles tendon with a medial paratendinous approach, Achilles tendon microcirculation was assessed using combined Laser-Doppler and spectrophotometry (Oxygen-to-see) regarding: - tendinous capillary blood flow [arbitrary units AU] - tendinous tissue oxygen saturation [%] - tendinous venous filling pressure [rAU] The main body of the Achilles tendon was measured in the center of the suture with 50 Hz. 10 minutes after Achilles tendon suture (6-0 Prolene), a second assessment of microcirculatory parameters was performed. Results Achilles tendon capillary blood flow decreased by 57% following the suture (70 ± 30 AU vs. 31 ± 16 AU; p < 0.001). Tendinous tissue oxygen saturation remained at the same level before and after suture (78 ± 17% vs. 77 ± 22%; p = 0.904). Tendinous venous filling pressure increased by 33% (54 ± 16 AU vs. 72 ± 20 AU; p = 0.019) after suture. Conclusion Achilles tendon suture in anaesthetised rats causes an acute loss of capillary perfusion and increases postcapillary venous filling pressures indicating venous stasis. The primary hypothesis of this study was confirmed. In contrast, tendinous tissue oxygen saturation remains unchanged excluding acute intratendinous hypoxia within the first 10 minutes after suture. Further changes of oxygen saturation remain unclear. Furthermore, it remains to be determined to what extent reduced capillary blood flow as well as increased postcapillary stasis might influence tendon healing from a microcirculatory point of view in this animal setting

  5. Granuloma formation secondary to Achilles tendon repair with nonabsorbable suture

    PubMed Central

    Kara, Adnan; Celik, Haluk; Seker, Ali; Uysal, Mehmet Ali; Uzun, Metin; Malkoc, Melih

    2014-01-01

    INTRODUCTION Several complications can be observed after Achilles tendon repairs. In this study we aimed to report granuloma formation secondary to Achilles tendon repair with Ethibond (Ethicon INC, Somerville, New Jersey) suture. PRESENTATION OF CASE A 31 year-old man operated for Achilles tendon rupture. The Ethibond suture was used for primary repair. The patient attended to polyclinic with the complaints of swelling and discharge around the operation site four months after operation. A mass around distal portion of the Achilles tendon was detected. The granulomatous tissue was excised. Inside the mass Ethibond suture was detected. On histopathologic examination, typical findings of the foreign body reaction were observed. No microorganism was cultivated in the tissue culture. The patient has no complaint on the twelfth month control after surgery. DISCUSSION The results of primary repair of Achilles tendon are good but several complications were reported. In tendon repairs generally nonabsorbable sutures are used. The Ethibond is nonabsorbable, braided suture. In the literature, granuloma formations secondary to the suture materials such as polygylactine and braided polyethylen–polyester after Achilles tendon repair were reported but granuloma secondary to the Ethibond is very rare. CONCLUSION Although Ethibond suture is a strong and safe material for Achilles tendon repairs it may cause soft tissue problems such as granuloma. PMID:25212905

  6. Harnessing endogenous stem/progenitor cells for tendon regeneration

    PubMed Central

    Lee, Chang H.; Lee, Francis Y.; Tarafder, Solaiman; Kao, Kristy; Jun, Yena; Yang, Guodong; Mao, Jeremy J.

    2015-01-01

    Current stem cell–based strategies for tissue regeneration involve ex vivo manipulation of these cells to confer features of the desired progenitor population. Recently, the concept that endogenous stem/progenitor cells could be used for regenerating tissues has emerged as a promising approach that potentially overcomes the obstacles related to cell transplantation. Here we applied this strategy for the regeneration of injured tendons in a rat model. First, we identified a rare fraction of tendon cells that was positive for the known tendon stem cell marker CD146 and exhibited clonogenic capacity, as well as multilineage differentiation ability. These tendon-resident CD146+ stem/progenitor cells were selectively enriched by connective tissue growth factor delivery (CTGF delivery) in the early phase of tendon healing, followed by tenogenic differentiation in the later phase. The time-controlled proliferation and differentiation of CD146+ stem/progenitor cells by CTGF delivery successfully led to tendon regeneration with densely aligned collagen fibers, normal level of cellularity, and functional restoration. Using siRNA knockdown to evaluate factors involved in tendon generation, we demonstrated that the FAK/ERK1/2 signaling pathway regulates CTGF-induced proliferation and differentiation of CD146+ stem/progenitor cells. Together, our findings support the use of endogenous stem/progenitor cells as a strategy for tendon regeneration without cell transplantation and suggest this approach warrants exploration in other tissues. PMID:26053662

  7. Ultrasound Diagnosis of Bilateral Quadriceps Tendon Rupture After Statin Use

    PubMed Central

    Nesselroade, Ryan D.; Nickels, Leslie Connor

    2010-01-01

    Simultaneous bilateral quadriceps tendon rupture is a rare injury. We report the case of bilateral quadriceps tendon rupture sustained with minimal force while refereeing a football game. The injury was suspected to be associated with statin use as the patient had no other identifiable risk factors. The diagnosis was confirmed using bedside ultrasound. PMID:21079697

  8. A rare knee extensor mechanism injury: Vastus intermedius tendon rupture

    PubMed Central

    Cetinkaya, Engin; Aydin, Canan Gonen; Akman, Yunus Emre; Gul, Murat; Arikan, Yavuz; Aycan, Osman Emre; Kabukcuoglu, Yavuz Selim

    2015-01-01

    Introduction Quadriceps tendon injuries are rare. There is a limited number of studies in the literature, reporting partial quadriceps tendon ruptures. We did not find any study reporting an isolated vastus intermedius tendon injury in the literature. Presentation of case A 22 years old professional rugby player with the complaints of pain in the right lower limb, decreased range of motion in right knee and a mass in the mid-anterior of the right thigh applied following an overloading on his hyperflexed knee during a rugby match. T2 sequence magnetic resonance images revealed discontinuity in the vastus intermedius tendon and intramuscular hematoma. The patient has been conservatively treated. Discussion Quadriceps tendon ruptures generally occur after the 4th decade in the presence of degenerative changes. Our case is a young professional rugby player. Isolated vastus intermedius tendon rupture is unusual. Conservative treatment is performed as the intermedius tendon is in the deepest layer of the quadriceps muscle. Conclusion We report the first case of isolated rupture of the vastus intermedius tendon in the literature and we claim that disorder may be succesfully treated with conservative treatment and adequate physiotheraphy. PMID:26298093

  9. Relationship between tendon stiffness and failure: a metaanalysis.

    PubMed

    LaCroix, Andrew S; Duenwald-Kuehl, Sarah E; Lakes, Roderic S; Vanderby, Ray

    2013-07-01

    Tendon is a highly specialized, hierarchical tissue designed to transfer forces from muscle to bone; complex viscoelastic and anisotropic behaviors have been extensively characterized for specific subsets of tendons. Reported mechanical data consistently show a pseudoelastic, stress-vs.-strain behavior with a linear slope after an initial toe region. Many studies report a linear, elastic modulus, or Young's modulus (hereafter called elastic modulus) and ultimate stress for their tendon specimens. Individually, these studies are unable to provide a broader, interstudy understanding of tendon mechanical behavior. Herein we present a metaanalysis of pooled mechanical data from a representative sample of tendons from different species. These data include healthy tendons and those altered by injury and healing, genetic modification, allograft preparation, mechanical environment, and age. Fifty studies were selected and analyzed. Despite a wide range of mechanical properties between and within species, elastic modulus and ultimate stress are highly correlated (R(2) = 0.785), suggesting that tendon failure is highly strain-dependent. Furthermore, this relationship was observed to be predictable over controlled ranges of elastic moduli, as would be typical of any individual species. With the knowledge gained through this metaanalysis, noninvasive tools could measure elastic modulus in vivo and reasonably predict ultimate stress (or structural compromise) for diseased or injured tendon. PMID:23599401

  10. Simultaneous bilateral quadriceps tendon rupture while playing basketball.

    PubMed

    Shah, M; Jooma, N

    2002-04-01

    Simultaneous bilateral quadriceps tendon rupture is an uncommon injury in healthy people and only a few cases have been reported in athletes. This is the first report of a patient with simultaneous bilateral quadriceps tendon rupture incurred while playing basketball. The injury was surgically repaired and the patient had a good functional outcome. PMID:11916903

  11. New finding in the radiographic diagnosis of Achilles tendon rupture

    SciTech Connect

    Newmark, H.; Mellon, W.S. Jr.; Malhotra, A.K.; Olken, S.M.; Halls, J.

    1982-06-01

    The authors describe a new radiographic sign of rupture of the Achilles tendon system. It is a fracture, with separation through an osteophyte at the insertion of this tendon. Previously reported signs are also discussed as well as the present case report.

  12. Response of rabbit Achilles tendon to chronic repetitive loading.

    PubMed

    Archambault, J M; Hart, D A; Herzog, W

    2001-01-01

    The objective of this work was to assess the response of tendon to chronic repetitive loading. Controlled muscle stimulation was used to load the rabbit Achilles tendon at a frequency of 1.25 Hz for two hours per day, three days per week for a period of 11 weeks. Average peak tendon force was 26 N during the protocol. The loading protocol did not modify the gross morphology of the tissue, nor its water content or cellularity. Increases in mRNA expression of collagen Type III and MMPs were observed, but no signs of injury were detected by histologic examination of tendon and paratenon structures. The lack of a detectable injury response suggests that the tendons were not loaded beyond their capacity for repair. Factors additional to mechanical loading such as aging, illness or stress may be necessary to produce pathology. PMID:11696985

  13. Specialisation of extracellular matrix for function in tendons and ligaments

    PubMed Central

    Birch, Helen L.; Thorpe, Chavaunne T.; Rumian, Adam P.

    2013-01-01

    Summary Tendons and ligaments are similar structures in terms of their composition, organisation and mechanical properties. The distinction between them stems from their anatomical location; tendons form a link between muscle and bone while ligaments link bones to bones. A range of overlapping functions can be assigned to tendon and ligaments and each structure has specific mechanical properties which appear to be suited for particular in vivo function. The extracellular matrix in tendon and ligament varies in accordance with function, providing appropriate mechanical properties. The most useful framework in which to consider extracellular matrix differences therefore is that of function rather than anatomical location. In this review we discuss what is known about the relationship between functional requirements, structural properties from molecular to gross level, cellular gene expression and matrix turnover. The relevance of this information is considered by reviewing clinical aspects of tendon and ligament repair and reconstructive procedures. PMID:23885341

  14. IDENTIFICATION OF A TENDON PHENOTYPE IN GDF6 DEFICIENT MICE

    PubMed Central

    Mikic, Borjana; Rossmeier, Kerri; Bierwert, LouAnn

    2009-01-01

    Increasing evidence suggests that the growth/differentiation factors, GDFs 5, 6, and 7 in particular, may play a role in tendon and ligament biology. Mice with genetic mutations in Gdf5 have altered tendon composition and mechanical behavior, while animals with functional null mutations in Gdf7 have a more subtle tendon phenotype. The present study demonstrates for the first time that a null mutation in Gdf6 is associated with substantially lower levels of tail tendon collagen content (−33%) in four-week-old male mice, which has direct functional consequences for the mechanical integrity of the tissue (45-50% reduction in material properties). These data support a role for GDF6 in tendon matrix modeling. PMID:19248159

  15. System and Method for Tensioning a Robotically Actuated Tendon

    NASA Technical Reports Server (NTRS)

    Reiland, Matthew J. (Inventor); Diftler, Myron A. (Inventor)

    2013-01-01

    A tendon tensioning system includes a tendon having a proximal end and a distal end, an actuator, and a motor controller. The actuator may include a drive screw and a motor, and may be coupled with the proximal end of the tendon and configured to apply a tension through the tendon in response to an electrical current. The motor controller may be electrically coupled with the actuator, and configured to provide an electrical current having a first amplitude to the actuator until a stall tension is achieved through the tendon; provide a pulse current to the actuator following the achievement of the stall tension, where the amplitude of the pulse current is greater than the first amplitude, and return the motor to a steady state holding current following the conclusion of the pulse current.

  16. Neglected bilateral rupture of the patellar tendon: A case report.

    PubMed

    Cherrad, Taoufik; Louaste, Jamal; Kasmaoui, El Houcine; Bousbaä, Hicham; Rachid, Khaled

    2015-12-01

    Simultaneous bilateral rupture of the patellar tendon (PT) is extremely rare and is generally associated to some chronic diseases. When the rupture becomes chronic, it is more difficult to repair that as it remained untreated. The diagnosis, which is clinical, is often delayed, guided by standard radiography and confirmed by ultrasound or MRI. The management of a bilateral neglected, chronic patellar tendon rupture must address some serious difficulties: the proximally retracted patella, the reconstruction of the patellar tendon, finally, the temporary protection of this repair. We report a case of neglected bilateral rupture of the patellar tendon in a chronic hemodialysis patient, treated with a plastic surgery of the ipsilateral quadriceps tendon. PMID:26566349

  17. Force Model for Control of Tendon Driven Hands

    NASA Technical Reports Server (NTRS)

    Pena, Edward; Thompson, David E.

    1997-01-01

    Knowing the tendon forces generated for a given task such as grasping via a model, an artificial hand can be controlled. A two-dimensional force model for the index finger was developed. This system is assumed to be in static equilibrium, therefore, the equations of equilibrium were applied at each joint. Constraint equations describing the tendon branch connectivity were used. Gaussian elimination was used to solve for the unknowns of the Linear system. Results from initial work on estimating tendon forces in post-operative hands during active motion therapy were discussed. The results are important for understanding the effects of hand position on tendon tension, elastic effects on tendon tension, and overall functional anatomy of the hand.

  18. Torque Control of Underactuated Tendon-driven Robotic Fingers

    NASA Technical Reports Server (NTRS)

    Abdallah, Muhammad E. (Inventor); Ihrke, Chris A. (Inventor); Reiland, Matthew J. (Inventor); Wampler, Charles W. (Inventor); Diftler, Myron A. (Inventor); Platt, Robert (Inventor); Bridgwater, Lyndon (Inventor)

    2013-01-01

    A robotic system includes a robot having a total number of degrees of freedom (DOF) equal to at least n, an underactuated tendon-driven finger driven by n tendons and n DOF, the finger having at least two joints, being characterized by an asymmetrical joint radius in one embodiment. A controller is in communication with the robot, and controls actuation of the tendon-driven finger using force control. Operating the finger with force control on the tendons, rather than position control, eliminates the unconstrained slack-space that would have otherwise existed. The controller may utilize the asymmetrical joint radii to independently command joint torques. A method of controlling the finger includes commanding either independent or parameterized joint torques to the controller to actuate the fingers via force control on the tendons.

  19. Pectoralis major tendon rupture. Surgical procedures review.

    PubMed Central

    Merolla, Giovanni; Paladini, Paolo; Campi, Fabrizio; Porcellini, Giuseppe

    2012-01-01

    Summary Pectoralis major (PM) muscle is the powerful dynamic stabiliser of the shoulder that acts as a flexor, adductor and internal rotator. The rupture of the PM tendon is a relatively rare injury that was firstly described in a French boy by Patissier in 1822 and later, in 1861, by Letenneur who reported another similiar case. To date, over 200 cases have been published. In this article we describe the clinical anatomy and the mechanism of injuries of PM and we review the surgical procedures for acute and chronic ruptures. PMID:23738281

  20. Tendon Transfers for the Hypoplastic Thumb.

    PubMed

    Wall, Lindley B; Goldfarb, Charles A

    2016-08-01

    Thumb hypoplasia is a component of radial longitudinal deficiency. The severity of hypoplasia can range from a slightly smaller thumb to a complete absence. Types II and IIIA hypoplastic thumbs are candidates for reconstruction to improve function, stability, and strength. There are 2 commonly used tendon transfers that can augment thumb opposition strength: the Huber abductor digiti minimi muscle transfer and the flexor digitorum superficialis opposition transfer. Both transfers use ulnar-sided structures to augment the thenar musculature. The Huber opposition transfer increases thenar bulk, but does not provide additional tissue for metacarpophalangeal stability. PMID:27387085

  1. Do Dietary Factors Influence Tendon Metabolism?

    PubMed

    Scott, Alex; Nordin, Cara

    2016-01-01

    There is very little direct research to conclusively prove the relevance of diet in primary tendinopathies, however it seems prudent to ask whether our current knowledge about the impact of nutrition on collagen metabolism could be useful in assessing, preventing, or treating tendinopathy. The objective of this chapter is to discuss the potential impact (negative or positive) that nutrition may have on the metabolism of tendons by summarizing the related research. The chapter briefly discusses the roles that specific vitamins, amino acids, lipids, and antioxidants have in various processes of the body that may be directly or indirectly related to tenocyte metabolism. PMID:27535270

  2. Mechanical model of a single tendon finger

    NASA Astrophysics Data System (ADS)

    Rossi, Cesare; Savino, Sergio

    2013-10-01

    The mechanical model of a single tendon three phalanxes finger is presented. By means of the model both kinematic and dynamical behavior of the finger itself can be studied. This finger is a part of a more complex mechanical system that consists in a four finger grasping device for robots or in a five finger human hand prosthesis. A first prototype has been realized in our department in order to verify the real behavior of the model. Some results of both kinematic and dynamical behavior are presented.

  3. Repetitive jumping and sprinting until exhaustion alters hamstring reflex responses and tibial translation in males and females.

    PubMed

    Behrens, Martin; Mau-Moeller, Anett; Wassermann, Franziska; Plewka, Antje; Bader, Rainer; Bruhn, Sven

    2015-11-01

    The incidence of anterior cruciate ligament injuries is considerably higher in females than in males and the underlying mechanisms are still under debate. Research indicates that the neuromuscular system of females and males might respond differently to the same fatigue protocol due to differences in muscle activation during movement tasks. This study analyzed sex differences in hamstring reflex responses and posterior-anterior tibial translation (TT) before and after fatiguing exercise. We measured the isolated movement of the tibia relative to the femur as a consequence of mechanically induced TT in standing subjects as well as muscle activity of the hamstrings before and after repetitive jumping and sprinting until exhaustion. Muscle fatigue delayed reflex onset latencies in females and males. A reduction in reflex responses associated with an increased TT was observed after fatiguing exercise for both sexes. Data indicate that the used fatigue protocol altered the latency and magnitude of reflex responses as well as TT in females and males. Based on the results of previous research and the outcome of this study, it might be that sex-specific effects of fatigue on reflex activity and mechanical stability of the knee depend on the kind of fatiguing exercise. PMID:25941064

  4. Focusing on Increasing Velocity during Heavy Resistance Knee Flexion Exercise Boosts Hamstring Muscle Activity in Chronic Stroke Patients.

    PubMed

    Vinstrup, Jonas; Calatayud, Joaquin; Jakobsen, Markus D; Sundstrup, Emil; Andersen, Lars L

    2016-01-01

    Background. Muscle strength is markedly reduced in stroke patients, which has negative implications for functional capacity and work ability. Different types of feedback during strength training exercises may alter neuromuscular activity and functional gains. Objective. To compare levels of muscle activity during conditions of blindfolding and intended high contraction speed with a normal condition of high-intensity knee flexions. Methods. Eighteen patients performed unilateral machine knee flexions with a 10-repetition maximum load. Surface electromyography (EMG) was recorded from the quadrics and hamstring muscles and normalized to maximal EMG (nEMG) of the nonparetic limb. Results. For the paretic leg, the speed condition showed higher values of muscle activity compared with the normal and blindfolded conditions for both biceps femoris and semitendinosus. Likewise, the speed condition showed higher co-contraction values compared with the normal and blindfolded conditions for the vastus lateralis. No differences were observed between exercise conditions for the nonparetic leg. Conclusion. Chronic stroke patients are capable of performing heavy resistance training with intended high speed of contraction. Focusing on speed during the concentric phase elicited higher levels of muscle activity of the hamstrings compared to normal and blindfolded conditions, which may have implications for regaining fast muscle strength in stroke survivors. PMID:27525118

  5. Focusing on Increasing Velocity during Heavy Resistance Knee Flexion Exercise Boosts Hamstring Muscle Activity in Chronic Stroke Patients

    PubMed Central

    Jakobsen, Markus D.

    2016-01-01

    Background. Muscle strength is markedly reduced in stroke patients, which has negative implications for functional capacity and work ability. Different types of feedback during strength training exercises may alter neuromuscular activity and functional gains. Objective. To compare levels of muscle activity during conditions of blindfolding and intended high contraction speed with a normal condition of high-intensity knee flexions. Methods. Eighteen patients performed unilateral machine knee flexions with a 10-repetition maximum load. Surface electromyography (EMG) was recorded from the quadrics and hamstring muscles and normalized to maximal EMG (nEMG) of the nonparetic limb. Results. For the paretic leg, the speed condition showed higher values of muscle activity compared with the normal and blindfolded conditions for both biceps femoris and semitendinosus. Likewise, the speed condition showed higher co-contraction values compared with the normal and blindfolded conditions for the vastus lateralis. No differences were observed between exercise conditions for the nonparetic leg. Conclusion. Chronic stroke patients are capable of performing heavy resistance training with intended high speed of contraction. Focusing on speed during the concentric phase elicited higher levels of muscle activity of the hamstrings compared to normal and blindfolded conditions, which may have implications for regaining fast muscle strength in stroke survivors. PMID:27525118

  6. Electromechanical delay of the hamstrings during eccentric muscle actions in males and females: Implications for non-contact ACL injuries.

    PubMed

    De Ste Croix, Mark B A; ElNagar, Youssif O; Iga, John; James, David; Ayala, Francisco

    2015-12-01

    Sex differences in neuromuscular functioning has been proposed as one of the factors behind an increased relative risk of non-contact anterior cruciate ligament (ACL) injury in females. The aim of this study was to explore sex differences in electromechanical delay (EMD) of the hamstring muscles during eccentric muscle actions and during a range of movement velocities. This study recruited 110 participants (55 males, 55 females) and electromyography of the semitendinosus, semimembranosus and biceps femoris was determined during eccentric actions at 60, 120 and 240°/s. No significant sex differences were observed irrespective of muscle examined or movement velocity. Irrespective of sex EMD significantly increased with increasing movement velocity (P < 0.01). There was no significant difference in the EMD of the 3 muscles examined. Our findings suggest that during eccentric actions of the hamstrings that there are no sex differences, irrespective of movement velocity. This would suggest that other factors are probably responsible for the increased relative risk of non-contact ACL injury in females compared to males. PMID:26522999

  7. Characterization of mechanical and biochemical properties of developing embryonic tendon

    PubMed Central

    Marturano, Joseph E.; Arena, Jeffrey D.; Schiller, Zachary A.; Georgakoudi, Irene; Kuo, Catherine K.

    2013-01-01

    Tendons have uniquely high tensile strength, critical to their function to transfer force from muscle to bone. When injured, their innate healing response results in aberrant matrix organization and functional properties. Efforts to regenerate tendon are challenged by