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1

Tendon transfers for irreparable rotator cuff tears.  

PubMed

Tendon transfer is one treatment option for patients with massive irreparable rotator cuff tears. Although surgical indications are not clearly defined, the traditional thought is that the ideal candidate is young and lacks significant glenohumeral arthritis. The proposed benefits of tendon transfers are pain relief and potential increase in strength. The biomechanical rationale for the procedure is to restore the glenohumeral joint force couple and possibly to restore normal shoulder kinematics. The selection of donor tendon depends on the location of the rotator cuff deficiency. Transfers of latissimus dorsi and pectoralis major tendons have been shown to consistently improve pain; however, functional benefits are unpredictable. Trapezius tendon transfer may be an alternative in patients with massive posterosuperior rotator cuff tears, although longer-term follow-up is required. PMID:23908255

Omid, Reza; Lee, Brian

2013-08-01

2

Intramuscular Rotator Cuff Cysts: Association with Tendon Tears on MRI and Arthroscopy  

Microsoft Academic Search

OBJECTIVE. This study was designed to explore the relationship between intramuscular cysts and rotator cuff tendon tears. CONCLUSION. Intramuscular cysts are strongly associated with rotator cuff tendon tears. Identification of such a cyst should prompt a search for a rotator cuff tear. Findings on MR arthrography and surgery suggest that a delaminating component of the rotator cuff tear may lead

Ara Kassarjian; Martin Torriani; Hugue Ouellette; William E. Palmer

3

Biceps Tendon Tear at the Shoulder  

MedlinePLUS

... your shoulder socket. These tissues are called the rotator cuff. They cover the head of your upper arm ... other parts of your shoulder, such as the rotator cuff tendons. Top of page Cause There are two ...

4

Simultaneous rupture of bilateral quadriceps tendon and rotator cuff tear: a case report.  

PubMed

This is a case report of a patient who sustained both a bilateral quadriceps tendon rupture and a complete rotator cuff tear. Overuse is a known risk factor for rotator cuff tears, but this case suggests that it can also be a risk factor for quadriceps tendon rupture. PMID:23155972

Chen, H T

2012-03-01

5

US appearance of partial-thickness supraspinatus tendon tears: Application of the string theory. Pictorial essay.  

PubMed

The supraspinatus tendon is composed of 5 different layers consisting of intertwining bundles. On a front portion of the tendon, the layers become coated bundles which insert on the trochanter. At the insertion, the superficial or bursal surface of the tendon corresponding to the tendon fibers in contact with the subacromial bursa can be distinguished from the deep surface corresponding to the fibers in contact with the glenohumeral joint. A tendon tear may involve partial or total disruption of the tendon fibers and is called full-thickness tear if it affects the entire tendon, and partial-thickness tear if it involves only part of the tendon. Partial-thickness tears of the supraspinatus tendon include lesions of the superficial, deep and central surface or tendon delamination.A contrast enhanced examination requires injection of contrast agent into the joint (arthrography followed by computed tomography (CT) or magnetic resonance imaging (MRI)) to study the deep surface, and injection into the subacromial bursa (bursography followed by CT) to study the superficial surface. MRI and ultrasound (US) examination allow the study of these different tendon layers without the use of contrast agent (which is not possible at CT). PMID:23396264

Guerini, H; Fermand, M; Godefroy, D; Feydy, A; Chevrot, A; Morvan, G; Gault, N; Drapé, J L

2012-01-15

6

US appearance of partial-thickness supraspinatus tendon tears: Application of the string theory. Pictorial essay  

PubMed Central

The supraspinatus tendon is composed of 5 different layers consisting of intertwining bundles. On a front portion of the tendon, the layers become coated bundles which insert on the trochanter. At the insertion, the superficial or bursal surface of the tendon corresponding to the tendon fibers in contact with the subacromial bursa can be distinguished from the deep surface corresponding to the fibers in contact with the glenohumeral joint. A tendon tear may involve partial or total disruption of the tendon fibers and is called full-thickness tear if it affects the entire tendon, and partial-thickness tear if it involves only part of the tendon. Partial-thickness tears of the supraspinatus tendon include lesions of the superficial, deep and central surface or tendon delamination. A contrast enhanced examination requires injection of contrast agent into the joint (arthrography followed by computed tomography (CT) or magnetic resonance imaging (MRI)) to study the deep surface, and injection into the subacromial bursa (bursography followed by CT) to study the superficial surface. MRI and ultrasound (US) examination allow the study of these different tendon layers without the use of contrast agent (which is not possible at CT).

Guerini, H.; Fermand, M.; Godefroy, D.; Feydy, A.; Chevrot, A.; Morvan, G.; Gault, N.; Drape, J.L.

2012-01-01

7

Traumatic full-thickness infraspinatus and teres minor tendon tears.  

PubMed

The patient was a 23-year-old male professional American football player who played wide receiver. He injured his right shoulder 3 days earlier during practice, diving to catch a pass and landing on his right arm while it was outstretched overhead. When he landed on the ground, the patient reported that he felt his right shoulder dislocate. Based on the patient's mechanism of injury and the findings of a physical examination by an orthopaedic surgeon and a physical therapist, radiographs and magnetic resonance imaging were ordered. Though the radiographs were interpreted as normal, magnetic resonance imaging revealed full-thickness infraspinatus and teres minor tendon tears at their insertion sites on the humerus. PMID:23902742

Cain, E Lyle; Andrachuk, John; Wilk, Kevin E

2013-07-31

8

Arthroscopic Repair of Full-Thickness Tears of the Supraspinatus: Does the Tendon Really Heal?  

Microsoft Academic Search

Background: Good functional results have been reported for arthroscopic repair of rotator cuff tears, but the rate of tendon-to-bone healing is still unknown. Our hypothesis was that arthroscopic repair of full-thickness supraspinatus tears achieves a rate of complete tendon healing equivalent to those reported in the literature with open or mini-open techniques. Methods: Sixty-five consecutive shoulders with a chronic full-thickness

PASCAL BOILEAU; NICOLAS BRASSART; DUNCAN J. WATKINSON; MICHEL CARLES; ARMODIOS M. HATZIDAKIS; SUMANT G. KRISHNAN

9

Exogenous collagen cross-linking recovers tendon functional integrity in an experimental model of partial tear.  

PubMed

We investigated the hypothesis that exogenous collagen cross-linking can augment intact regions of tendon to mitigate mechanical propagation of partial tears. We first screened the low toxicity collagen cross-linkers genipin, methylglyoxal and ultra-violet (UV) light for their ability to augment tendon stiffness and failure load in rat tail tendon fascicles (RTTF). We then investigated cross-linking effects in load bearing equine superficial digital flexor tendons (SDFT). Data indicated that all three cross-linking agents augmented RTTF mechanical properties but reduced native viscoelasticity. In contrast to effects observed in fascicles, methylglyoxal treatment of SDFT detrimentally affected tendon mechanical integrity, and in the case of UV did not alter tendon mechanics. As in the RTTF experiments, genipin cross-linking of SDFT resulted in increased stiffness, higher failure loads and reduced viscoelasticity. Based on this result we assessed the efficacy of genipin in arresting tendon tear propagation in cyclic loading to failure. Genipin cross-linking secondary to a mid-substance biopsy-punch significantly reduced tissue strains, increased elastic modulus and increased resistance to fatigue failure. We conclude that genipin cross-linking of injured tendons holds potential for arresting tendon tear progression, and that implications of the treatment on matrix remodeling in living tendons should now be investigated. PMID:22102295

Fessel, Gion; Wernli, Jeremy; Li, Yufei; Gerber, Christian; Snedeker, Jess G

2011-11-18

10

Single injection of platelet-rich plasma in a rat Achilles tendon tear model  

PubMed Central

Summary The purpose of this study was to determine the efficacy of platelet-rich plasma (PRP) 1-injection during an Achilles tendon rat tear model. 80 male adult imbreded rats (Wistar Kyoto), underwent under surgical tendon rupture. 40 Animal (PRP group rats) were given a local injection with 0,25 mL of PRP, and 40 animal (control group) were given the same quantity of control solution. The rats were sacrified at 1, 2, 4 and 6 weeks (each time point, 20 rats of the each group) after surgical tear and tendon tissue was analysed by macroscopic aspect, histology, immunostaining and Real Time (RT)-PCR to evaluate tissue repair. PRP improved tendon remodelling by better coordination of the reconstructive process with earlier formation of tendon-like continuity only in the first week after surgery. However, after 2,4 and 6 weeks, Achilles tendons in the PRP group had no difference compared to the control group. Immunostaining and RT-PCR did not show any difference between PRP treated and untreated group. Based on these findings a single injection of PRP appear not useful for Achilles rat tendon tear.

Parafioriti, Antonina; Armiraglio, Elisabetta; Del Bianco, Silvia; Tibalt, Elisabetta; Oliva, Francesco; Berardi, Anna C.

2011-01-01

11

Sonography findings in tears of the extensor pollicis longus tendon and correlation with CT, MRI and surgical findings  

Microsoft Academic Search

We present our experience in the diagnosis of extensor pollicis longus tendon tears using different imaging methods. In the past 2 years, 12 patients (7 males, 5 females) with extension deficit of distal phalanx of thumb were diagnosed with extensor pollicis longus tendon (EPL) rupture by means of different imaging methods. The ultrasound pattern consisted of a gap between tendon

Fernando Ruiz Santiago; Pilar Garófano Plazas; Juan Miguel Tristán Fernández

2008-01-01

12

Clinics in diagnostic imaging (148). Bursal-sided partial-thickness supraspinatus tendon tear.  

PubMed

Rotator cuff injury comprises a continual spectrum of lesions ranging from tendinopathy, which may progress to partial- or full-thickness tear. This progression may be influenced by the interplay of extrinsic and intrinsic factors. We describe the case of a 29-year-man who presented with right shoulder pain for one year. His initial magnetic resonance (MR) arthrogram showed supraspinatus tendinopathy. Subsequent MR arthrogram, obtained after a road traffic accident, showed a bursal-sided partial-thickness tear of the supraspinatus tendon. In view of his worsening clinical symptoms, surgery was performed ten months later, revealing a full-thickness rotator cuff tear near the tendon insertion, with a tight subacromial space and bony protuberance of the humeral head. The pathogenesis of rotator cuff injuries, the roles of different imaging modalities in the diagnosis of rotator cuff injuries, as well as the advantages and limitations of various radiological modalities, are discussed. PMID:24068062

Bhagwani, S G; Peh, W C

2013-09-01

13

Shoulder ultrasound: diagnostic accuracy for impingement syndrome, rotator cuff tear, and biceps tendon pathology.  

PubMed

We sought to determine the accuracy of ultrasound for the preoperative evaluation of shoulder impingement syndrome, rotator cuff tear, and abnormalities of the long head of the biceps tendon. The findings in 42 consecutive surgical cases were compared with the preoperative sonographic readings. Ultrasound detected all of the 10 full-thickness cuff tears identified at surgery (sensitivity 1.0, specificity 0.97) but detected only 6 of 13 partial-thickness cuff tears (sensitivity 0.46, specificity 0.97). A full-thickness tear was falsely diagnosed in one case of severe cuff abrasion. Dynamic scan criteria correctly diagnosed impingement in 27 of 34 cases (sensitivity 0.79, positive predictive value 0.96). Abnormalities of the long head of the biceps were accurately diagnosed with the exception of low-grade tendinitis and the superior labral tear, anterior to posterior, lesion. We concluded that ultrasound is a sensitive and accurate method of identifying patients with full-thickness tears of the rotator cuff, extracapsular biceps tendon pathology, or both. Dynamic ultrasound can help confirm, but not exclude, a clinical diagnosis of impingement. PMID:9658352

Read, J W; Perko, M

14

Latissimus Dorsi Tendon Transfer for Irreparable Rotator Cuff Tears: A Modified Technique Using Arthroscopy  

PubMed Central

Latissimus dorsi transfer is a well-established method for the treatment of posterosuperior massive irreparable rotator cuff tears. We propose using an arthroscopically assisted technique that avoids insult to the deltoid. With the patient in the lateral decubitus position, an L-shaped incision is made along the anterior belly of the latissimus muscle and then along the posterior axillary line. The latissimus and teres major are identified and separated. The tendon insertion of the latissimus is isolated, and a FiberWire traction suture (Arthrex, Naples, FL) is placed, facilitating dissection of the muscle to the thoracodorsal neurovascular pedicle and subsequent mobilization. The interval deep to the deltoid and superficial to the teres minor is developed into a subdeltoid tunnel for arthroscopic tendon transfer. The latissimus tendon is then transferred and stabilized arthroscopically to the lateral aspect of the infraspinatus and supraspinatus footprints by multiple suture anchors.

Villacis, Diego; Merriman, Jarrad; Wong, Karlton; Rick Hatch, George F.

2013-01-01

15

The role of the biceps tendon in massive rotator cuff tears.  

PubMed

Tendinopathy of the long head of the biceps (LHB) tendon commonly occurs in patients with rotator cuff tears, and the inflammation of one head tends to lead to inflammation of the other. Many theories have been proposed regarding the function of the LHB tendon; however, its exact purpose is poorly understood. It has been described as an important stabilizer of the glenohumeral joint, a depressor of the humeral head, and as a vestigial structure. The LHB tendon can be a significant source of pain in patients with rotator cuff tears. The appropriate treatment depends on the patient's age, comorbidities, activity level, extent of disability, the presence of rotator cuff arthropathy, and the quality of the rotator cuff tissue. Conservative treatment is usually attempted first, with modalities such as nonsteroidal anti-inflammatory drugs, corticosteroid injections, physical therapy, and activity modification. If symptoms persist, biceps tenotomy or tenodesis may be combined with rotator cuff repair, depending on the quality of the rotator cuff tissue, the severity of rotator cuff arthropathy, and the willingness of the patient to comply with postoperative immobilization and rehabilitation. Even when rotator cuff repair is not possible, isolated tenotomy or tenodesis of the LHB tendon can provide substantial pain relief. PMID:22301226

Pill, Stephan G; Walch, Gilles; Hawkins, Richard J; Kissenberth, Michael J

2012-01-01

16

Clinical results of a surgical technique using endobuttons for complete tendon tear of pectoralis major muscle: report of five cases  

PubMed Central

Background We herein describe a surgical technique for the repair of complete tear of the pectoralis major (PM) tendon using endobuttons to strengthen initial fixation. Methods Five male patients (3 judo players, 1 martial arts player, and 1 body builder) were treated within 2 weeks of sustaining complete tear of the PM tendon. Average age at surgery and follow-up period were 28.4 years (range, 23-33) and 28.8 months (range, 24-36). A rectangular bone trough (about 1 × 4 cm) was created on the humerus at the insertion of the distal PM tendon. The tendon stump was introduced into this trough, and fixed to the reverse side of the humeral cortex using endobuttons and non-absorbable suture. Clinical assessment of re-tear was examined by MRI. Shoulder range of motion (ROM), outcome of treatment, and isometric power were measured at final follow-up. Results There were no clinical re-tears, and MRI findings also showed continuity of the PM tendon in all cases at final follow-up. Average ROM did not differ significantly between the affected and unaffected shoulders. The clinical outcomes at final follow-up were excellent (4/5 cases) or good (1/5). In addition, postoperative isometric power in horizontal flexion of the affected shoulder showed complete recovery when compared with the unaffected side. Conclusions Satisfactory outcomes could be obtained when surgery using the endobutton technique was performed within 2 weeks after complete tear of the PM tendon. Therefore, our new technique appears promising as a useful method to treat complete tear of the PM tendon.

2011-01-01

17

Biceps tendon properties worsen initially but improve over time following rotator cuff tears in a rat model  

PubMed Central

Damage to the biceps tendon is often seen in conjunction with rotator cuff tears. However, controversy exists regarding its role in the shoulder and its optimal treatment. A previous study determined that biceps tendons were detrimentally affected in the presence of rotator cuff tears in the rat model and this damage worsened over time. However, whether this damage progresses at later time points to provide a chronic model is unknown. The objective of this study was to determine the changes in the biceps tendon in the presence of a cuff tear over time. Our hypothesis was that histological, compositional, organizational and mechanical properties would worsen with time. We detached the supraspinatus and infraspinatus tendons of 48 rats and evaluated these properties at 1, 4, 8 and 16 weeks post detachment. Properties worsened through 8 weeks, but improved between 8 and 16 weeks. We therefore conclude that biceps tendon changes in this model are not truly chronic. Additionally, it has been shown that infraspinatus properties in this model return to normal by 16 weeks, when biceps properties improve, indicating that earlier repair of one or more of the rotator cuff tendons may lead to resolved pathology of the long head of the biceps tendon.

Peltz, Cathryn D.; Hsu, Jason E.; Zgonis, Miltiadis H.; Trasolini, Nicholas A.; Glaser, David L.; Soslowsky, Louis J.

2012-01-01

18

Acute traumatic tear of gluteus medius and minimus tendons in a patient without antecedant peritrochanteric hip pain.  

PubMed

Morphologic similarities between the abductor mechanisms of the hip and shoulder have given rise to the term rotator cuff tear of the hip. Although the true incidence of gluteus medius and minimus tears in the general population is unknown, the association between these tears and recalcitrant lateral hip pain has been described as greater trochanteric pain syndrome. Historically, tears of the gluteus medius and minimus have been thought to be attritional, and associated with chronic peritrochanteric pain, found incidentally during fracture fixation or hip arthroplasty, or with failure of abductor repair following arthroplasty utilizing the anterolateral approach. The literature supports favorable clinical outcomes with operative repair utilizing either endoscopic or open techniques. To our knowledge, there has never been a reported case of an acute traumatic tear of the gluteus medius and minimus that occurred without antecedant peritrochanteric hip pain. In this case, the patient was treated with acute open repair of the gluteus medius and minimus tendons within 3 weeks of injury and excellent clinical results were obtained at 6-month follow-up. Of note, the patient was notified and gave consent for his case to be used in publication. PMID:23569702

Stanton, Michael C; Maloney, Michael D; Dehaven, Kenneth E; Giordano, Brian D

2012-06-01

19

Acute Traumatic Tear of Gluteus Medius and Minimus Tendons in a Patient Without Antecedant Peritrochanteric Hip Pain  

PubMed Central

Morphologic similarities between the abductor mechanisms of the hip and shoulder have given rise to the term rotator cuff tear of the hip. Although the true incidence of gluteus medius and minimus tears in the general population is unknown, the association between these tears and recalcitrant lateral hip pain has been described as greater trochanteric pain syndrome. Historically, tears of the gluteus medius and minimus have been thought to be attritional, and associated with chronic peritrochanteric pain, found incidentally during fracture fixation or hip arthroplasty, or with failure of abductor repair following arthroplasty utilizing the anterolateral approach. The literature supports favorable clinical outcomes with operative repair utilizing either endoscopic or open techniques. To our knowledge, there has never been a reported case of an acute traumatic tear of the gluteus medius and minimus that occurred without antecedant peritrochanteric hip pain. In this case, the patient was treated with acute open repair of the gluteus medius and minimus tendons within 3 weeks of injury and excellent clinical results were obtained at 6-month follow-up. Of note, the patient was notified and gave consent for his case to be used in publication.

Stanton, Michael C.; Maloney, Michael D.; DeHaven, Kenneth E.; Giordano, Brian D.

2012-01-01

20

Incomplete joint side tear of the subscapularis tendon with a small fragment in an adolescent tennis player: a case report  

PubMed Central

Case In this case report, we presented the case of an adolescent tennis player with avulsion injury of the subscapularis tendon of the right shoulder. Patients A 17-year-old right-hand-dominant male tennis player visited our hospital complaining of pain in the anterior aspect of the right shoulder. We performed X-ray and three-dimensional computed tomography (3D-CT) and magnetic resonance imaging (MRI) scans for the diagnosis. Results Plain radiographs did not reveal the presence of lesion; however, 3D-CT and MRI scans showed a small bony fragment located between the humeral head and the glenoid of the scapula and a high-intensity area of the subscapularis tendon. He was subsequently diagnosed with incomplete joint side tear of the subscapularis tendon with a small bony fragment. Subsequently, we performed arthroscopic excision of the bony fragment and repair of the subscapularis tendon. Conclusions This case highlighted the presence of an injury with minor trauma associated with repeated tennis strokes in a skeletally immature patient.

2012-01-01

21

Tendonitis  

MedlinePLUS

... Achilles tendonitis or rotator cuff tendonitis, ultrasound or magnetic resonance imaging (MRI) scans may be used to ... gov/ American Academy of Orthopaedic Surgeons (AAOS) 6300 North River Road Rosemont, IL 60018-4262 Phone: 847- ...

22

MRI findings with arthroscopic correlation for tear of discoid lateral meniscus: comparison between children and adults.  

PubMed

BackgroundDiscoid lateral meniscus is more susceptible to tear than normal meniscus. A comparison study for tear types of discoid lateral meniscus between children and adults has not been reported.PurposeTo compare tear type of surgically proven discoid lateral meniscus between adults and children, and to analyze diagnostic performance for tear type of discoid lateral meniscus using magnetic resonance imaging (MRI).Material and MethodsKnee MR examinations of 53 children and 84 adults who had discoid lateral menisci identified at arthroscopic surgery were retrospectively evaluated with consensus by two radiologists for tear type including displacement of torn meniscus. MRI findings were compared with surgery as the reference standard. The difference of tear type and displacement of torn meniscus between children and adults in arthroscopic finding was analyzed using the Fisher's exact test or the Chi-squared test with Bonferroni's correction.ResultsAt arthroscopy, complex tear (children, n = 22; adults, n = 56) and peripheral tear (children, n = 17; adults, n = 8) differed significantly between children and adults (P = 0.006 for complex tear, P = 0.002 for peripheral tear). Displacement of torn meniscus was seen in 28 cases of children and 41 cases of adults, not a statistically significant difference. In children, the positive predictive value (PPV) for horizontal tears was 90%, for peripheral tears 60%, and for complex tears 57%. PPV in adults for horizontal tears was 78%, peripheral tears 25%, and for complex tears 89%.ConclusionComplex tears were more commonly found in adults than children and peripheral tears were more commonly found in children than adults. MRI has a high PPV for diagnosing the type of tear in discoid lateral meniscus for horizontal tears in children and adults and for complex tears in adults. PMID:23463861

Jung, Jee Young; Choi, Sang-Hee; Ahn, Jin Hwan; Lee, Seung Ah

2013-03-01

23

Correlations of isokinetic measurements with tendon healing following open repair of rotator cuff tears  

Microsoft Academic Search

The aim of this study was to investigate the correlation of tendon integrity following open cuff repairs with functional and\\u000a isokinetic strength measurements. Twenty-six shoulders of 25 patients were included in this study. At the final follow-up,\\u000a 14 repairs (53.8%) were intact and 12 repairs (46.2%) had failed on magnetic resonance imaging (MRI). Mean UCLA score at latest\\u000a follow-up was

Huseyin Demirors; Esra Circi; Rahmi Can Akgun; Nefise Cagla Tarhan; Nuri Cetin; Sercan Akpinar; Ismail Cengiz Tuncay

2010-01-01

24

Prevalence of triceps tendon tears on MRI of the elbow and clinical correlation  

Microsoft Academic Search

Objective  Triceps tendon injuries are reported to be very rare. To our knowledge, there have been no studies describing its prevalence\\u000a or injury patterns on MR imaging. The purpose of this retrospective study was to determine the prevalence and patterns of\\u000a triceps injuries based on a large series of consecutive MR examinations. Clinical correlation was obtained.\\u000a \\u000a \\u000a \\u000a \\u000a Materials and Methods  From 801 consecutive

Monica C. Koplas; Erika Schneider; Murali Sundaram

2011-01-01

25

Latissimus dorsi tendon transfer for irreparable tears of the rotator cuff: An anatomical study to assess the neurovascular hazards and ways of improving tendon excursion.  

PubMed

Latissimus dorsi tendon transfer (LDTT) is technically challenging. In order to clarify the local structural anatomy, we undertook a morphometric study using six complete cadavers (12 shoulders). Measurements were made from the tendon to the nearby neurovascular structures with the arm in two positions: flexed and internally rotated, and adducted in neutral rotation. The tendon was then transferred and measurements were taken from the edge of the tendon to a reference point on the humeral head in order to assess the effect of a novel two-stage release on the excursion of the tendon. With the shoulder flexed and internally rotated, the mean distances between the superior tendon edge and the radial nerve, brachial artery, axillary nerve and posterior circumflex artery were 30 mm (26 to 34), 28 mm (17 to 39), 21 mm (12 to 28) and 15 mm (10 to 21), respectively. The mean distance between the inferior tendon edge and the radial nerve, brachial artery and profunda brachii artery was 18 mm (8 to 27), 22 mm (15 to 32) and 14 mm (7 to 21), respectively. Moving the arm to a neutral position reduced these distances. A mean of 15 mm (8 to 21) was gained from a standard soft-tissue release, and 32 mm (20 to 45) from an extensile release. These figures help to define further the structural anatomy of this region and the potential for transfer of the latissimus dorsi tendon. PMID:23539704

Henry, P D G; Dwyer, T; McKee, M D; Schemitsch, E H

2013-04-01

26

Detection of partial-thickness supraspinatus tendon tears: is a single direct MR arthrography series in ABER position as accurate as conventional MR arthrography?  

Microsoft Academic Search

Purpose  The purpose of this study was to retrospectively evaluate sensitivity and specificity of a single magnetic resonance (MR)\\u000a arthrography series in abduction external rotation (ABER) position compared with conventional MR arthrography for detection\\u000a of supraspinatus tendon tears, with arthroscopy as gold standard, and to assess interobserver variability.\\u000a \\u000a \\u000a \\u000a Materials and methods  Institutional review board approval was obtained; informed consent was waived. MR

Saskia A. Schreinemachers; Victor P. M. van der Hulst; W. Jaap Willems; Shandra Bipat; Henk-Jan van der Woude

2009-01-01

27

A biomechanical comparison between the central one-third patellar tendon and the residual tendon.  

PubMed Central

The purpose of this study was to compare the tensile strength of the central one third patellar tendon--as used for reconstruction of the anterior cruciate ligament--to that of the residual patellar tendon. Ten matched pairs of human cadaveric knees were used for this study, each specimen consisting of an intact patella-patellar tendon-proximal tibial unit. One knee from each pair was randomly selected for removal of both the medial and lateral one third of the patellar tendon, leaving the central one third intact. The contralateral knee of each pair underwent removal of the central one third of the patellar tendon, leaving the residual two thirds intact. Each specimen was then mounted in a materials testing machine and tensile tested to failure at a strain rate of 100%.s-1. The most important result to emerge from these experiments was that there was no significant difference in maximum force to failure for the residual patellar tendon compared to the central one third. Thus any thought that removal of the central one third as a graft still leaves a tendon twice as wide and therefore twice as strong as a graft is dispelled by these experiments. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Matava, M J; Hutton, W C

1995-01-01

28

Tendon stem cells: experimental and clinical perspectives in tendon and tendon-bone junction repair  

PubMed Central

Summary Tendon and tendon-bone junction injuries, while heal, have high re-tear rates. Mesenchymal stem cells (MSCs) have great appeal for the promotion of tendon and tendon-bone junction healing because of their high proliferation rate, multi-potency and relative ease of isolation from various tissues. Tendon stem cells have been identified recently and could be an alternative new cell source for tendon and tendon-bone junction repair. In this review, we summarized the in vitro characteristics of tendon stem cells. The evidence supporting the potential use of these cells for tendon and tendon-bone junction repair was presented. In order to therapeutically apply tendon stem cells in the clinical settings, standardization of tendon stem cell culture is essential. Issues relating to the sources, purity, efficacy, safety and delivery of tendon stem cells for tendon and tendon-bone junction repair were summarized and discussed. The direction for future research was suggested.

Lui, Pauline Po Yee; Wong, On Tik

2012-01-01

29

Tendon stem cells: experimental and clinical perspectives in tendon and tendon-bone junction repair.  

PubMed

Tendon and tendon-bone junction injuries, while heal, have high re-tear rates. Mesenchymal stem cells (MSCs) have great appeal for the promotion of tendon and tendon-bone junction healing because of their high proliferation rate, multi-potency and relative ease of isolation from various tissues. Tendon stem cells have been identified recently and could be an alternative new cell source for tendon and tendon-bone junction repair. In this review, we summarized the in vitro characteristics of tendon stem cells. The evidence supporting the potential use of these cells for tendon and tendon-bone junction repair was presented. In order to therapeutically apply tendon stem cells in the clinical settings, standardization of tendon stem cell culture is essential. Issues relating to the sources, purity, efficacy, safety and delivery of tendon stem cells for tendon and tendon-bone junction repair were summarized and discussed. The direction for future research was suggested. PMID:23738293

Lui, Pauline Po Yee; Wong, On Tik

2012-10-16

30

Comparison of camel tear proteins between summer and winter  

PubMed Central

Purpose Proteins in the tear fluid have positive effects on maintaining the integrity and stabilization of the tear film, which is affected by several environmental factors. The aim of this study is to investigate seasonal variation of protein patterns in camel tears collected during the summer and winter season. Methods Tears from both eyes of 50 clinically normal camels (Camelus dromedarius) were collected in the summer (June – July) and in the winter (December – January) respectively. Pooled tear protein samples from two seasons were separated by SDS–PAGE and two-dimensional electrophoresis (2-DE). Protein spots of differential expression in two season gels were excised and subjected to in-gel digestion and identification by matrix assisted laser desorption/ionization-time of flight/time of flight-mass spectrum (MALDI-TOF/TOF-MS) analysis. Two differentially expressed proteins, lactoferrin (LF) and vitelline membrane outer layer protein 1 homolog (VMO1 homolog), were validated by western blotting. Results Thirteen well resolved bands were detected in SDS–PAGE gels of both summer and winter camel tears. By band densitometry, significantly higher intensities of band 6, 7, 11, and lower intensity of band 13 were observed in the summer group compared to the winter group. In 2-DE profiles of camel tears, four protein spots were found expressed differentially in two seasons. Further protein identification by MALDI-TOF/TOF-MS and confirmation by western blotting indicated that there was a significant decrease in LF (p=0.002) and an increase in VMO1 homolog (p=0.042) in tears in the summer compared to the winter. Conclusions The seasonal variation of camel tear fluids has been found in the composition of proteins, including LF and VMO1 homolog. This result will expand our knowledge of physiologic characteristics of tear fluids and establish a foundation for the mechanistic studies and clinical practices on ocular surface disorders.

Chen, Ziyan; Shamsi, Farrukh A.; Li, Kaijun; Huang, Qiang; Al-Rajhi, Ali A.; Chaudhry, Imtiaz A.

2011-01-01

31

Quadriceps Tendon Tear  

MedlinePLUS

... Specific exercises can restore strength and range of motion. Exercises will gradually be added to your program. ... move more freely with a greater range of motion. You will be prescribed more strengthening exercises as ...

32

Partial ACL tears augmented with distally inserted hamstring tendons and over-the-top fixation: An MRI evaluation  

Microsoft Academic Search

This study evaluated the mid-term MRI appearance of partial ACL tear augmentation with quadrupled distally inserted hamstrings, while preserving the intact ACL bundle. Twenty-eight patients with ACL partial tear underwent augmentation. After 15–40 months follow-up, patients were evaluated clinically and by MRI. The mean IKDC score at follow-up was 93.8. Twenty-five patients were rated as excellent, three as fair. The mean

R. Buda; F. Di Caprio; L. Giuriati; D. Luciani; M. Busacca; S. Giannini

2008-01-01

33

Histopathology of rotator cuff tears.  

PubMed

The pathogenesis of rotator cuff tears is multifactorial. Tendon abnormalities of the rotator cuff include alteration of collagen fiber structure, tenocytes, cellularity, and vascularity. Ruptured tendons show marked collagen degeneration and disordered arrangement of collagen fibers. Fibroblast population decreases as the size of the tear in the rotator cuff increases. The larger fibroblast population seen in the smaller tears is also actively proliferating and is part of an active reparative process. Inflammatory cell infiltrate correlates inversely to rotator cuff tear size in the torn supraspinatus tendon samples, with larger tears showing a marked reduction in all cell types. As tear size increase, there is also a progressive decrease in the number of blood vessels. Whether rotator cuff tear heals spontaneously is an important pathologic and clinical question. Histologic changes indicative of repair and inflammation lead to consider biological options in addition to biomechanical treatment of the rotator cuff tears. PMID:21822106

Longo, Umile Giuseppe; Berton, Alessandra; Khan, Wasim S; Maffulli, Nicola; Denaro, Vincenzo

2011-09-01

34

Subscapularis tears.  

PubMed

The subscapularis muscle is the largest and strongest muscle of the rotator cuff. It plays an essential role in the stability and function of the shoulder. Tears of the subscapularis tendon are more frequent than previously estimated. The worldwide use of arthroscopy in rotator cuff surgery has allowed to recognize the true prevalence of subscapularis lesions, as it permits to visualize the articular side where partial tears are usually localized. Subscapularis tears are generally non-traumatic, arising from intrinsic degeneration, subcoracoid and/or anterosuperior impingement. Clinical presentation is usually characterized by history of pain, typically located anteriorly, and difficulty in lifting movements across the chest, or twisting inwards that hinders activities of daily life. Special tests for the diagnosis of subscapularis tears include the lift-off, belly-press, and bear-hug tests. Imaging of the subscapularis tendon may involve plain radiography, magnetic resonance and ultrasound scanning, but MRI better characterizes subscapular tears and coexistent shoulder pathology. The management of subscapularis tears is aimed at restoring the integral role of this muscle in the shoulder. Operative management is indicated for most patients because it is the only one to allow restoration of subscapularis function. Arthroscopic repair can be safely and successfully performed. It requires tendon mobilization to reach the lesser tuberosity. If this is not possible, its footprint can be medialized up to 5-7 mm. Arthroscopic results are encouraging. At intermediate follow-up, improvement in functional scores and patient satisfaction has been reported. Outcomes are comparable to that of open repair, with a very low complication rate and no major intraoperative complications. PMID:21986050

Longo, Umile Giuseppe; Berton, Alessandra; Marinozzi, Andrea; Maffulli, Nicola; Denaro, Vincenzo

2011-10-04

35

Fifteen-Year Outcome of Endoscopic Anterior Cruciate Ligament Reconstruction With Patellar Tendon Autograft for ‘‘Isolated’’ Anterior Cruciate Ligament Tear  

Microsoft Academic Search

Background: Few studies report the long-term results of anterior cruciate ligament rupture and single-incision endoscopic reconstructive surgery. Outcomes are often clouded by concomitant meniscal, chondral, or ligament injuries.Purpose: To determine the 15-year outcomes of anterior cruciate ligament ruptures treated with endoscopic anterior cruciate ligament reconstruction using middle-third patellar tendon autograft.Study Design: Case series; Level of evidence, 4.Methods: Between January 1993

Catherine Hui; Lucy J. Salmon; Alison Kok; Shinichi Maeno; James Linklater; Leo A. Pinczewski

2011-01-01

36

A Five-Year Comparison of Patellar Tendon Versus Four-Strand Hamstring Tendon Autograft for Arthroscopic Reconstruction of the Anterior Cruciate Ligament  

Microsoft Academic Search

Background: The choice of graft material for anterior cruciate ligament reconstruction is believed to play a major role in outcome, but most comparisons of graft choice have not been well controlled.Hypothesis: The choice of graft material (patellar tendon or hamstring tendon) does affect clinical outcome after anterior cruciate ligament reconstruction.Study Design: Prospective, nonrandomized clinical trial.Methods: Two groups of 90 patients

Leo A. Pinczewski; David J. Deehan; Lucy J. Salmon; Vivianne J. Russell; Amanda Clingeleffer

2002-01-01

37

Pectoralis major tears: comparison of surgical and conservative treatment  

PubMed Central

Objectives—To compare objective measures of strength and subjective functional outcomes in complete distal pectoralis major tears treated either surgically or non-surgically. Methods—Twenty two pectoralis major tears were included in 21 patients. Ten were surgically repaired and 12 were managed non-surgically. Patients completed a standard questionnaire, and clinical examination and isokinetic dynamometry were carried out. Results—In patients who had surgical repair, peak torque returned to 99% of that of the uninjured side and work performed returned to 97%. For those managed conservatively, peak torque and work performed returned to only 56% of that of the uninjured side (p = 0.003 for the difference in peak torque, and p = 0.01 for work performed). Findings were independent of the strength of the patient, whether or not the dominant arm was involved, the age of the patient, and the length of time from injury or surgery to testing. Patients were grouped into one of three subjective functional outcome groups, and those who had a surgical repair had a better functional outcome. Conclusions—Surgical repair results in greater recovery of peak torque and work performed than conservative management of patients with rupture of the pectoralis major. Key Words: pectoralis major; muscle tears; isokinetic strength testing

Hanna, C; Glenny, A; Stanley, S; Caughey, M

2001-01-01

38

The distal biceps tendon.  

PubMed

Distal biceps tendon ruptures continue to be an important injury seen and treated by upper extremity surgeons. Since the mid-1980s, the emphasis has been placed on techniques that limit complications or improve initial tendon-to-bone fixation strength. Recently, basic science research has expanded the knowledge base regarding the biceps tendon structure, footprint anatomy, and biomechanics. Clinical data have further delineated the results of conservative and surgical management of both partial and complete tears in acute or chronic states. The current literature on the distal biceps tendon is described in detail. PMID:23474326

Schmidt, Christopher C; Jarrett, Claudius D; Brown, Brandon T

2013-03-07

39

Meniscal tears--comparison of arthrography, CT, and MRI.  

PubMed

A total of 1750 knees were prospectively evaluated using a high-resolution noninvasive axial computed tomography (CT) scanning technique. A total of 203 knees underwent subsequent arthroscopic or arthrographic evaluation. In this group, the sensitivity of CT for the detection of a torn meniscus was 88.5%; the specificity was 95.5%; and the accuracy was 91.5%. An additional 270 knees were prospectively evaluated by both CT and magnetic resonance imaging (MRI) to determine the ability of both techniques to characterize knee menisci in patients believed to have meniscal tears. Of these knees, 94 were subsequently examined by arthroscopy. In this group, the overall accuracy of MRI for detecting a torn meniscus was 89.5% and for CT it was 92.2%. Properly performed, both CT and MRI are accurate and effective methods for noninvasively evaluating meniscal abnormalities in the acutely injured knee. The protocol for CT and MRI meniscus imaging as well as interpretation are presented in addition to their relative roles with respect to arthrography and arthroscopy. PMID:2653727

Manco, L G; Berlow, M E

1989-01-01

40

Comparison of SPECT bone scintigraphy with MRI for diagnosis of meniscal tears  

PubMed Central

Background Scintigraphy has been considered as competitive to MRI, but limited data are available on the accuracy of single photon emission tomography (SPECT) compared with MRI for the assessment of meniscal tears. Our objective was to assess the value of SPECT in comparison to MRI. Methods Between January 2003 and March 2004, sixteen patients were studied with both modalities and the accuracy rates of SPECT scan results, and MRI findings in the diagnosis of meniscal tears were compared. Arthroscopy was the gold standard. Results The respective sensitivity rate, specificity rate, and positive and negative predictive accuracies of MRI were 89%, 94%, 93%, and 79% and for SPECT those were 78%, 94%, 94%, and 88%. There was good agreement on the presence or absence of tears between two modalities (? statistic = 0.699). Conclusion SPECT and MRI are both valuable imaging techniques. SPECT is a useful alternative when MRI is unavailable or unsuitable and it is beneficial when more possible accuracy is desired (such as when MRI results are either inconclusive or conflict with other clinical data).

Tahmasebi, Mohammad-naghi; Saghari, Mohsen; Moslehi, Masoud; Gholamrezanezhad, Ali

2005-01-01

41

Biomechanical comparison of four methods of repair of the Achilles tendon: a laboratory study with bovine tendons.  

PubMed

We tested four types of surgical repair for load to failure and distraction in a bovine model of Achilles tendon repair. A total of 20 fresh bovine Achilles tendons were divided transversely 4 cm proximal to the calcaneal insertion and randomly repaired using the Dresden technique, a Krackow suture, a triple-strand Dresden technique or a modified oblique Dresden technique, all using a Fiberwire suture. Each tendon was loaded to failure. The force applied when a 5 mm gap was formed, peak load to failure, and mechanism of failure were recorded. The resistance to distraction was significantly greater for the triple technique (mean 246.1 N (205 to 309) to initial gapping) than for the Dresden (mean 180 N (152 to 208); p = 0.012) and the Krackow repairs (mean 101 N (78 to 112; p < 0.001). Peak load to failure was significantly greater for the triple-strand repair (mean 675 N (453 to 749)) than for the Dresden (mean 327.8 N (238 to 406); p < 0.001), Krackow (mean 223.6 N (210 to 252); p < 0.001) and oblique repairs (mean 437.2 N (372 to 526); p < 0.001). Failure of the tendon was the mechanism of failure for all specimens except for the tendons sutured using the Krackow technique, where the failure occurred at the knot. The triple-strand technique significantly increased the tensile strength (p = 0.0001) and gap resistance (p = 0.01) of bovine tendon repairs, and might have advantages in human application for accelerated post-operative rehabilitation. PMID:22529088

Ortiz, C; Wagner, E; Mocoçain, P; Labarca, G; Keller, A; Del Buono, A; Maffulli, N

2012-05-01

42

Biomechanical comparison of stimulated and nonstimulated skeletal muscle pulled to failure  

Microsoft Academic Search

We compared the biomechanical properties of passive and stimulated muscle rapidly lengthened to failure in an experimental animal model. The mechanical param eters compared were force to tear, change in length to tear, site of failure, and energy absorbed by the muscle- tendon unit before failure. Paired comparisons were made between 1) muscles stimulated at 64 Hz (tetanic stimulation) and

William E. Garrett; Marc R. Safran; Anthony V. Seaber; Richard R. Glisson; Beth M. Ribbeck

1987-01-01

43

Basic mechanisms of tendon fatigue damage.  

PubMed

Pathologic processes intrinsic and extrinsic to the tendons have been proposed as the underlying cause of rotator cuff disease, but the precise etiology is not known. Tear formation is, in part, attributable to the accumulation of subrupture tendon fatigue damage. We review the molecular, mechanical, and structural changes induced in tendons subjected to controlled amounts of fatigue loading in an animal model of early tendinopathy. The distinct tendon responses to low and moderate levels of loading, as opposed to high levels, provide insight into the potential mechanisms for the therapeutic benefits of exercise in the treatment of rotator cuff tendinopathy. The progression of damage accumulation leading to fiber rupture and eventual tendon tearing seen with higher loading illustrates the progression from tendinopathy to full-thickness tearing. We hope that this more realistic animal model of tendon fatigue damage will allow better assessment of biologic, mechanical, tissue-engineering, and rehabilitation strategies to improve repair success. PMID:22244058

Neviaser, Andrew; Andarawis-Puri, Nelly; Flatow, Evan

2012-02-01

44

Rotator Cuff Tear - Surgery versus Rehabilitation  

Microsoft Academic Search

Rotator cuff tears are a common source of shoulder pain. . The incidence of rotator cuff damage increases with age and is most frequently due to degeneration of the tendon, rather than injury from sports or trauma. While the information that follows can be used as a guide for all types of rotator cuff tears, it is intended specifically for

Hythem P. Shadid

45

Clinical and biological aspects of rotator cuff tears.  

PubMed

Rotator cuff tears are common and are a frequent source of shoulder pain and disability. A wide variation in the prevalence of rotator cuff tears has been reported. The etiology of rotator cuff tear remains multifactorial and attempts to unify intrinsic and extrinsic theories tried to explain the etiopathogenesis of rotator cuff tears. Knowledge of the etiopathogenesis of rotator cuff tears is important to improve our therapies, surgical techniques and promote tendon repair. Several strategies have been proposed to enhance tendon healing and recently research has focused on regenerative therapies, such as Growth Factors (GFs) and Plasma Rich Platelet (PRP), with high expectations of success. PMID:23888289

Via, Alessio Giai; De Cupis, Mauro; Spoliti, Marco; Oliva, Francesco

2013-07-09

46

Biomechanical comparison of single-row, double-row, and transosseous-equivalent repair techniques after healing in an animal rotator cuff tear model.  

PubMed

The transosseous-equivalent (TOE) rotator cuff repair technique increases failure loads and contact pressure and area between tendon and bone compared to single-row (SR) and double-row (DR) repairs, but no study has investigated if this translates into improved healing in vivo. We hypothesized that a TOE repair in a rabbit chronic rotator cuff tear model would demonstrate a better biomechanical profile than SR and DR repairs after 12 weeks of healing. A two-stage surgical procedure was performed on 21 New Zealand White Rabbits. The right subscapularis tendon was transected and allowed to retract for 6 weeks to simulate a chronic tear. Repair was done with the SR, DR, or TOE technique and allowed to heal for 12 weeks. Cyclic loading and load to failure biomechanical testing was then performed. The TOE repair showed greater biomechanical characteristics than DR, which in turn were greater than SR. These included yield load (p?tear, the TOE technique was the strongest biomechanical construct after healing followed by DR with SR being the weakest. PMID:23572388

Quigley, Ryan J; Gupta, Akash; Oh, Joo-Han; Chung, Kyung-Chil; McGarry, Michelle H; Gupta, Ranjan; Tibone, James E; Lee, Thay Q

2013-04-09

47

The patellar tendon: thickening, internal signal buckling, and other MR variants  

Microsoft Academic Search

We studied the range of appearance of asymptomatic patellar tendons and evaluated the effect of age, weight, joint effusions, and anterior cruciate ligament (ACL) tears on this tendon. One hundred and seventy-three patellar tendons in asymptomatic patients were studied at 1.5 tesla. Sagittal short and long TE images were evaluated in regard to tendon thickness, ratio of thickness of patellar

Mark E. Schweitzer; Donald G. Mitchell; Saundra M. Ehrlich

1993-01-01

48

High-Intensity Focused Ultrasound Ablation of Ex Vivo Bovine Achilles Tendon  

Microsoft Academic Search

Small tears in tendons are a common occurrence in athletes and others involved in strenuous physical activity. Natural healing in damaged tendons can result in disordered regrowth of the underlying collagen matrix of the tendon. These disordered regions are weaker than surrounding ordered regions of normal tendon and are prone to re-injury. Multiple cycles of injury and repair can lead

Robert Muratore; Tal Akabas; Isabella B. Muratore

2008-01-01

49

Comparison of human tear film osmolarity measured by electrical impedance and freezing point depression techniques  

Microsoft Academic Search

Tear hyperosmolarity is diagnostic of dry eye disease (DED), yet difficulty in measurement has limited its utility; development of new instruments could facilitate its clinical application. This study compares the new OcuSense TearLab osmometer (OcuSense, Inc, San Diego, CA), based on electrical impedance “lab-on-a-chip” nanoliter technology, with the freezing point depression Clifton Osmometer (Clifton Technical Physics, Hartford, NY).

Alan Tomlinson; Louise C. McCann; Edward I Pearce

2010-01-01

50

Peroneus longus tear and its relation to the peroneal tubercle: A review of the literature  

PubMed Central

Summary Tear of the peroneal tendon may occur in different anatomical sites. The most prevalent site is around the lateral malleolus. Tear of the peroneus longus at the level of the peroneal tubercle is unusual. Anatomically, the lateral surface of the calcaneous can be divided into thirds. The middle third includes the peroneal tubercle, which separates the peroneus longus tendon from the peroneus brevis. An anatomic variation of the peroneal tubercle may lead to chronic irritation of the peroneus longus tendon that could ultimately cause a longitudinal tear. We conducted this review aiming to clarify the anatomy, biomechanics of the tendon, and the clinical features of tear of the peroneus longus tendon on the lateral surface of the calcaneous due to an enlarged peroneal tubercle. In addition, we reviewed the diagnostic and treatment options of peroneal tendon tears at this site.

Palmanovich, Ezequiel; Laver, Lior; Brin, Yaron S.; Kotz, Evgeny; Hetsroni, Iftach; Mann, Gideon; Nyska, Meir

2011-01-01

51

Comparison of mechanical properties of polyvinylidene fluoride and polypropylene monofilament sutures used for flexor tendon repair.  

PubMed

We performed an experimental study to evaluate the mechanical properties of polyvinylidene fluoride sutures and to compare their use with that of standard polypropylene sutures for the circumferential, epitendinous suture of a flexor tendon repair. Polyvinylidene fluoride sutures had a smaller suture diameter, a greater knot pull strength and less delayed extension when under creep testing, than polypropylene sutures. Tendons repaired using polyvinylidene fluoride sutures had significantly greater gap and breaking strengths than those repaired using polypropylene sutures. PMID:11386769

Wada, A; Kubota, H; Hatanaka, H; Miura, H; Iwamoto, Y

2001-06-01

52

Comparisons of intraosseous graft healing between the doubled flexor tendon graft and the bone–Patellar tendon–Bone graft in anterior cruciate ligament reconstruction  

Microsoft Academic Search

Purpose: The purpose of this study was to compare intraosseous graft healing between the doubled flexor tendon (FT) graft and the bone–patellar tendon–bone (BPTB) graft in anterior cruciate ligament (ACL) reconstruction. Type of Study: Randomized trial. Methods: A biomechanical and histologic study was conducted with 24 adult beagle dogs. Bilateral ACL reconstructions were performed in each animal. Autogenous doubled FT

Fumihisa Tomita; Kazunori Yasuda; Susumu Mikami; Toshihiko Sakai; Shuji Yamazaki; Harukazu Tohyama

2001-01-01

53

Arthroscopic Reconstruction of the Anterior Cruciate LigamentA Comparison of Patellar Tendon Autograft and Four-Strand Hamstring Tendon Autograft  

Microsoft Academic Search

We compared the outcome of anterior cruciate ligament reconstruction using hamstring tendon autograft with outcome using patellar tendon autograft at 2 years after surgery. Patients had an isolated anterior cruciate ligament injury and, apart from the grafts, the arthroscopic surgical technique was identical. Prospective assessment was performed on 90 patients with isolated anterior cruciate ligament injury undergoing reconstruction with a

Ian S. Corry; Jonathan M. Webb; Amanda J. Clingeleffer; Leo A. Pinczewski

1999-01-01

54

SLAP Tears  

MedlinePLUS

... caused by acute trauma or by repetitive shoulder motion. An acute SLAP injury may result from: A ... labrum tears as a result of repeated shoulder motion. Many SLAP tears, however, are the result of ...

55

Comparison of two ultrashort echo time sequences for the quantification of T1 within phantom and human Achilles tendon at 3 T.  

PubMed

Ultrashort echo time (UTE) techniques enable direct imaging of musculoskeletal tissues with short T2 allowing measurement of T1 relaxation times. This article presents comparison of optimized 3D variable flip angle UTE (VFA-UTE) and 2D saturation recovery UTE (SR-UTE) sequences to quantify T1 in agar phantoms and human Achilles tendon. Achilles tendon T1 values for asymptomatic volunteers were compared to Achilles tendon T1 values calculated from patients with clinical diagnoses of spondyloarthritis (SpA) and Achilles tendinopathy using an optimized VFA-UTE sequence. T1 values from phantom data for VFA- and SR-UTE compare well against calculated T1 values from an assumed gold standard inversion recovery spin echo sequence. Mean T1 values in asymptomatic Achilles tendon were found to be 725±42 ms and 698±54 ms for SR- and VFA-UTE, respectively. The patient group mean T1 value for Achilles tendon was found to be 957±173 ms (P<0.05) using an optimized VFA-UTE sequence with pulse repetition time of 6 ms and flip angles 4, 19, and 24°, taking a total 9 min acquisition time. The VFA-UTE technique appears clinically feasible for quantifying T1 in Achilles tendon. T1 measurements offer potential for detecting changes in Achilles tendon due to SpA without need for intravenous contrast agents. PMID:22246857

Wright, Peter; Jellus, Vladimir; McGonagle, Dennis; Robson, Matthew; Ridgeway, John; Hodgson, Richard

2012-01-13

56

Intra-articular Partial-Thickness Rotator Cuff TearsAnalysis of Injured and Repaired Strain Behavior  

Microsoft Academic Search

Background: There are few biomechanical studies regarding partial-thickness rotator cuff tears and subsequent repair.Hypothesis: Partial-thickness intra-articular supraspinatus tendon tears increase articular-sided tendon strain as they increase in size. Repair of these tears will return strain to the intact state.Study Design: Controlled laboratory study.Methods: Twenty fresh-frozen human cadaveric shoulders were prepared by dissecting to the supraspinatus tendon and leaving the native

Augustus D. Mazzocca; Lina M. Rincon; Robert W. OConnor; Elifho Obopilwe; Matthew Andersen; Lauren Geaney; Robert A. Arciero

2008-01-01

57

Comparison between resistive and collisionless double tearing modes for nearby resonant surfaces  

Microsoft Academic Search

The linear instability and nonlinear dynamics of collisional (resistive) and collisionless (due to electron inertia) double tearing modes (DTMs) are compared with the use of a reduced cylindrical model of a tokamak plasma. We focus on cases where two q = 2 resonant surfaces are located a small distance apart. It is found that regardless of the magnetic reconnection mechanism,

A. Bierwage; Qingquan Yu

2007-01-01

58

Subscapularis Function and Structural Integrity After Arthroscopic Repair of Isolated Subscapularis Tears  

Microsoft Academic Search

Background: Results of arthroscopic repair of isolated subscapularis tendon tears have not been widely studied. A detailed evaluation of subscapularis function with subscapularis strength quantification has not been performed to date.Purpose: To evaluate postoperative subscapularis muscle function and to assess the clinical outcome and structural tendon integrity with postoperative magnetic resonance imaging after arthroscopic repair of isolated subscapularis tears.Study Design:

Christoph Bartl; Gian M. Salzmann; Gernot Seppel; Stefan Eichhorn; Konstantin Holzapfel; Klaus Wörtler; Andreas B. Imhoff

2011-01-01

59

Tendon's ultrastructure  

PubMed Central

Summary The structure of a tendon is an important example of complexity of ECM three-dimensional organization. The extracellular matrix (ECM) is a macromolecular network with both structural and regulatory functions. ECM components belong to four major types of macromolecules: the collagens, elastin, proteoglycans, and noncollagenous glycoproteins. Tendons are made by a fibrous, compact connective tissue that connect muscle to bone designed to transmit forces and withstand tension during muscle contraction. Here we show the ultrastructural features of tendon’s components.

Tresoldi, Ilaria; Oliva, Francesco; Benvenuto, Monica; Fantini, Massimo; Masuelli, Laura; Bei, Roberto; Modesti, Andrea

2013-01-01

60

Comparison of TGF-?1 in tears and corneal haze following Epi-LASIK with and without mitomycin C  

PubMed Central

AIM To compare transforming growth factor-?1 (TGF-?1) levels in tears and the degree of corneal haze formation following epithelial laser in situ keratomileusis (Epi-LASIK) with and without the use of mitomycin C (MMC) and to investigate the effect of MMC on corneal wound healing. METHODS Thirty-two patients (64 eyes) with high myopia underwent Epi-LASIK surgery, and MMC was randomly used in one eye in each patient. The epithelialization process was observed, and the TGF-?1 level in tears was measured at 1 day, 3, and 7 days postoperatively for comparison with baseline. Corneal haze was graded at 1 month, 3, and 6 months after surgery. RESULTS Mean preoperative spherical equivalent refraction was -8.24±2.18D (range -6.00 to -10.50D) in the MMC group and -7.82±1.55D (range -6.00 to -9.75D) in the non-MMC group. There was no significant difference between the two groups (P=0.38). Mean epithelialization time was (5.02±0.68) days in the MMC group and (4.86±0.57) days in the non-MMC group (P=0.31). Tear fluid TGF-?1 levels were similar before surgery (P=0.34), but were significantly higher in the non-MMC group at 1 day, 3, and 7 days postoperatively (P=0.004, 0.008, and 0.012, respectively). Corneal haze scores 1 month after surgery were significantly higher in the non-MMC group (P=0.03), and similar at 3 and 6 months after surgery (P=0.28 and 0.62, respectively). CONCLUSION MMC did not delay epithelialization. In early postoperative period, lower TGF-?1 levels in tears and a lower grade of corneal haze were observed in the MMC group. Our findings suggest that the ability of MMC to inhibit Epi-LASIK-induced haze might be mediated through TGF-?1 suppression.

Chen, Jing; Chen, Yi; Han, Su-Ning

2013-01-01

61

Measuring Regional Changes in Damaged Tendon  

NASA Astrophysics Data System (ADS)

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.

Frisch, Catherine Kayt Vincent

62

Meniscus tears  

MedlinePLUS

Meniscus tears refer to a tear in the shock-absorbing cartilage (meniscus) of the knee. ... protect the joint. The meniscus serves as a shock-absorption system, assists in lubricating the knee joint, and limits the ability to flex and extend the joint.

63

Acute Rupture of the Anterior Cruciate Ligament and Patellar Tendon in a Collegiate Athlete  

Microsoft Academic Search

In rare incidences of combined ruptures of the ACL and patellar tendon, either the patellar tendon ruptures or the associated ACL tear is often initially missed. Even when recognized, there is no established treatment regimen. We report a case of an intercollegiate football player with a combined rupture of the ACL and patellar tendon that was successfully treated by primary

Lydia A. Futch; William P. Garth; Greg J. Folsom; William K. Ogard

2007-01-01

64

Repair of large supraspinatus rotator-cuff defects by infraspinatus and subscapularis tendon transfers in a cadaver model  

Microsoft Academic Search

Transosseous repair of a supraspinatus tendon (SSP) defect (Patte size II) can be difficult if the tendon is retracted and\\u000a the muscle atrophied. In this situation alternatives are margin convergence techniques, local tendon transfers or distant\\u000a tendon transfers in massive tears. The object of this study was to compare two local tendon transfers in terms of the feasibility\\u000a of the

Philip Kasten; Markus Loew; Markus Rickert

2007-01-01

65

Prospective Comparison of Auto and Allograft Hamstring Tendon Constructs for ACL Reconstruction  

PubMed Central

Although allograft use for primary anterior cruciate ligament reconstruction has continued to increase during the last 10 years, concerns remain regarding the long-term function of allografts (primarily that they may stretch with time) and clinical efficacy compared with autograft tendons. We attempted to address these issues by prospectively comparing identical quadrupled hamstring autografts with allograft constructs for primary anterior cruciate ligament reconstruction in patients with a minimum followup of 3 years. Eighty-four patients (37 with autografts and 47 with allografts) were enrolled; the mean followup was 52 ± 11 months for the autograft group and 48 ± 8 months for the allograft group. Outcome measurements included objective and subjective International Knee Documentation Committee scores, Lysholm scores, Tegner activity scales, and KT-1000 arthrometer measurements. The two cohorts were similar in average age, acute or chronic nature of the anterior cruciate ligament rupture, and incidence of concomitant meniscal surgeries. At final followup, we found no difference in terms of Tegner, Lysholm, KT-1000, or International Knee Documentation Committee scores. Five anterior cruciate ligament reconstructions failed: three in the autograft group and two in the allograft group. Our data suggest laxity is not increased in allograft tendons compared with autografts and clinical outcome scores 3 to 6 years after surgery are similar. Level of Evidence: Level II, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Edgar, Cory M.; Zimmer, Scott; Kakar, Sanjeev; Jones, Hugh

2008-01-01

66

Prospective comparison of auto and allograft hamstring tendon constructs for ACL reconstruction.  

PubMed

Although allograft use for primary anterior cruciate ligament reconstruction has continued to increase during the last 10 years, concerns remain regarding the long-term function of allografts (primarily that they may stretch with time) and clinical efficacy compared with autograft tendons. We attempted to address these issues by prospectively comparing identical quadrupled hamstring autografts with allograft constructs for primary anterior cruciate ligament reconstruction in patients with a minimum followup of 3 years. Eighty-four patients (37 with autografts and 47 with allografts) were enrolled; the mean followup was 52 +/- 11 months for the autograft group and 48 +/- 8 months for the allograft group. Outcome measurements included objective and subjective International Knee Documentation Committee scores, Lysholm scores, Tegner activity scales, and KT-1000 arthrometer measurements. The two cohorts were similar in average age, acute or chronic nature of the anterior cruciate ligament rupture, and incidence of concomitant meniscal surgeries. At final followup, we found no difference in terms of Tegner, Lysholm, KT-1000, or International Knee Documentation Committee scores. Five anterior cruciate ligament reconstructions failed: three in the autograft group and two in the allograft group. Our data suggest laxity is not increased in allograft tendons compared with autografts and clinical outcome scores 3 to 6 years after surgery are similar. Level of Evidence: Level II, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence. PMID:18575944

Edgar, Cory M; Zimmer, Scott; Kakar, Sanjeev; Jones, Hugh; Schepsis, Anthony A

2008-06-25

67

Minimally invasive A2 flexor tendon pulley and biomechanical comparison with two accepted techniques.  

PubMed

The increasing popularity of rock climbing and its associated injury of closed traumatic pulley A2 rupture has sparked investigator interest in pulley biomechanics. Biomechanically, the A2 and A4 pulleys are important for preventing bowstringing of the flexor tendon upon digital flexion. The literature is replete with reparative techniques for A2 pulley rupture. These techniques include direct fibrous tissue repair, as well as the use of palmaris longus autograft for single- and double-loop reconstruction. Through a previously undescribed minimally invasive double-anchor technique, we used palmaris longus tendon and 2-mm bioabsorbable suture anchors to reconstruct the A2 pulley at its anatomical location in a cadaver model. Then the ultimate load to failure of this reconstruction was tested against 2 known reconstructive techniques, namely, single-loop and double-loop palmaris repair. There was no significant difference between the strength of the previously described single-loop technique and our novel double-anchor technique. Furthermore, our minimally invasive repair obviated the need for the circumferential dissection and soft tissue trauma associated with the single- and double-loop repairs. PMID:18776779

Mallo, Gregory C; Sless, Yury; Hurst, Lawrence C; Serra-Hsu, Frederick

2008-09-01

68

A prospective comparison of bone-patellar tendon-bone and hamstring tendon grafts for anterior cruciate ligament reconstruction in male patients  

Microsoft Academic Search

The aim of the study was to compare the results after arthroscopic anterior cruciate ligament (ACL) reconstruction using central-third,\\u000a bone-patellar tendon-bone (BPTB Group) (n = 45) and four-strand semitendinosus\\/gracilis (ST\\/G Group) (n = 78) autografts in male patients. The type of study is non-randomised, prospective consecutive series. A consecutive series\\u000a of 126 male patients, all with unilateral ACL ruptures, was included in the study.

Gauti Laxdal; Ninni Sernert; Lars Ejerhed; Jon Karlsson; Jüri T. Kartus

2007-01-01

69

A Prospective, Randomized Comparison of Semitendinosus and Gracilis Tendon Versus Patellar Tendon Autografts for Anterior Cruciate Ligament ReconstructionFive-Year Follow-Up  

Microsoft Academic Search

Background: There are still controversies about graft selection for primary anterior cruciate ligament reconstruction. Prospective randomized long-term studies are needed to determine the differences between the materials.Hypothesis: Five years after anterior cruciate ligament reconstruction, there is a difference between hamstring and patellar tendon grafts in development of degenerative knee joint disease.Study Design: Randomized controlled trial; Level of evidence, 1.Methods: From

Matjaz Sajovic; Vilibald Vengust; Radko Komadina; Rok Tavcar; Katja Skaza

2006-01-01

70

Comparison of oil and phytosterol levels in germplasm accessions of corn, teosinte, and Job's tears.  

PubMed

Seeds of 49 accessions of corn (Zea mays ssp. mays), 9 accessions of teosinte (Zea species that are thought to be ancestors and probable progenitors to corn), and 3 accessions of Job's tears (Coix lacryma), obtained from a germplasm repository, were ground and extracted with hexane. Whole kernel oil yields and levels of four phytonutrients (free phytosterols, fatty acyl phytosterol esters, ferulate phytosterol esters, and gamma-tocopherol) in the oils were measured. Among the seeds tested, oil yields ranged from 2.19 to 4.83 wt %, the levels of ferulate phytosterol esters in the oil ranged from 0.047 to 0.839 wt %, the levels of free phytosterols in the oil ranged from 0.54 to 1.28 wt %, the levels of phytosterol fatty acyl esters in the oil ranged from 0.76 to 3.09 wt %, the levels of total phytosterols in the oil ranged from 1.40 to 4.38 wt %, and the levels of gamma-tocopherol in the oil ranged from 0.023 to 0.127 wt %. In general, higher levels of all three phytosterol classes were observed in seed oils from accessions of Zea mays ssp. mays than in seed oils from accessions of the other taxonomic groups. The highest levels of gamma-tocopherol were observed in teosinte accessions. PMID:11513668

Moreau, R A; Singh, V; Hicks, K B

2001-08-01

71

Comparison of the Insall–Salvati ratio of the patella in patients with and without an ACL tear  

Microsoft Academic Search

The object of this prospective study is to compare the Insall–Salvati ratio between the patients who have an anterior cruciate ligament (ACL) tear and receive arthroscopic–assistant ACL reconstruction and the patients who have no ACL tear but do have an internal disorder of the knee and receive arthroscopic surgery. We prospectively and consecutively collected into two groups a total of

Chien-Fu Jeff Lin; Jiunn-Jer Wu; Teng-Shung Chen; Tung-Fu Huang

2005-01-01

72

Nonarthroplasty options for the management of massive and irreparable rotator cuff tears.  

PubMed

Massive, irreparable rotator cuff tears remain a clinical challenge. In low-demand patients, debridement of the tear may relieve pain. Partial repair using the technique of margin convergence decreases the size of the tear gap and reduces strain. Biceps tenotomy or tenodesis has a role in providing pain relief in massive rotator cuff tears. Tendon transfers offer good results in patients with massive, irreparable rotator cuff tears. The treatment modality specifically chosen for the massive, irreparable rotator cuff tear must be tailored to the individual patient, their needs and expectations, and their ability to comply with intensive rehabilitation. PMID:23040556

Delaney, Ruth A; Lin, Albert; Warner, Jon J P

2012-10-01

73

Toward an Animal Model of the Human Tear Film: Biochemical Comparison of the Mouse, Canine, Rabbit, and Human Meibomian Lipidomes  

PubMed Central

Purpose. Secretions that are produced by meibomian glands (also known as meibum) are a major source of lipids for the ocular surface of humans and animals alike. Many animal species have been evaluated for their meibomian lipidomes. However, there have been a very small number of studies in which the animals were compared with humans side by side. Therefore, the purpose of this study was to compare meibum collected from humans and three typical laboratory animals, canines, mice, and rabbits, for their meibomian lipid composition in order to determine which animal species most resembles humans. Methods. High pressure liquid chromatography (HPLC) and gas-liquid chromatography (GLC) in combination with mass spectrometry were used to evaluate lipidomes of all tested species. Results. Among three tested animal species, mice were found to be the closest match to humans in terms of their meibomian lipidomes, while canines were the second closest species. The lipids of these three species were close to each other structurally and, for most lipid classes, quantitatively. The rabbit meibomian lipidome, on the other hand, was vastly different from lipidomes of all other tested species. Interestingly, a previously described class of lipids, acylated omega-hydroxy fatty acids (OAHFA), was found to be present in every tested species as the major amphiphilic component of meibum. Conclusions. Our side by side comparison of the rabbit and the human meibum demonstrated their vast differences. Thus, the rabbit seems to be a poor animal model of the human tear film, at least when studying its biochemistry and biophysics.

Butovich, Igor A.; Lu, Hua; McMahon, Anne; Eule, J. Corinna

2012-01-01

74

Comparison of M3DC1 Finite-Elements Code to Analytic Asymptotic Matching Solutions of Tearing Modes  

NASA Astrophysics Data System (ADS)

The M3DC1 implicit high-order two-fluid finite-element plasma-modeling code has been benchmarked in the linear resistive regime by comparison to an asymptotic matching solution for the case of a tearing mode instability in a circular cylindrical tokamak. The instability is driven by current and pressure gradients and involves reconnection of the magnetic field. The asymptotic matching technique combines the solution to the resistive magnetohydrodynamic (MHD) equations in the thin region around the mode rational surface with the solution to the ideal MHD equations beyond it. The M3DC1 and asymptotic matching results for the mode growth rate were compared over a wide range of Lundquist numbers (10^4

Ritchie, Andrew; Scaffidi, Thomas; Jardin, Stephen

2012-10-01

75

Two, Four, and Six-Strand Zone II Flexor Tendon Repairs: An In Situ Biomechanical Comparison Using a Cadaver Model  

Microsoft Academic Search

A dynamic in vitro model of zone II flexor tendon repair was used to compare gliding resistance, gap formation, and ultimate strength of the 2-, 4-, and 6-strand repair techniques. Each of 12 hands was mounted to a loading frame with 3 flexor tendons attached to individual pneumatic cylinders. A spring attached to a pin through the distal end of

R. Timothy Thurman; Thomas E. Trumble; Douglas P. Hanel; Allan F. Tencer; Patty K. Kiser

76

Comparison of Potentials of Stem Cells Isolated from Tendon and Bone Marrow for Musculoskeletal Tissue Engineering  

PubMed Central

The use of tendon-derived stem cells (TDSCs) as a cell source for musculoskeletal tissue engineering has not been compared with that of bone marrow stromal cells (BMSC). This study compared the mesenchymal stem cell (MSC) and embryonic stem cells (ESC) markers, clonogenicity, proliferative capacity, and multilineage differentiation potential of rat TDSC and BMSC in vitro. The MSC and ESC marker profiles of paired TDSC and BMSC were compared using flow cytometry and quantitative real-time polymerase chain reaction (qRT-PCR), respectively. Their clonogenicity and proliferative capacity were compared using colony-forming and 5-bromo-2?-deoxyuridine assays, respectively. The expression of tenogenic, osteogenic, and chondrogenic markers at basal state were examined using qRT-PCR. Their osteogenic, chondrogenic, and adipogenic differentiation potentials were compared using standard assays. TDSC and BMSC showed similar expression of CD90 and CD73. TDSC expressed higher levels of Oct4 than BMSC. TDSC exhibited higher clonogenicity, proliferated faster, and expressed higher tenomodulin, scleraxis, collagen 1 ? 1 (Col1A1), decorin, alkaline phosphatase, Col2A1, and biglycan messenger RNA levels than BMSC. There was higher calcium nodule formation and osteogenic marker expression in TDSC than BMSC upon osteogenic induction. More chondrocyte-like cells and higher glycosaminoglycan deposition and chondrogenic marker expression were observed in TDSC than BMSC upon chondrogenic induction. There were more oil droplets and expression of an adipogenic marker in TDSC than BMSC upon adipogenic induction. TDSC expressed higher Oct4 levels, which was reported to positively regulate mesendodermal lineage differentiation, showed higher clonogenicity and proliferative capacity, and had greater tenogenic, osteogenic, chondrogenic, and adipogenic markers and differentiation potential than BMSC. TDSC might be a better cell source than BMSC for musculoskeletal tissue regeneration.

Tan, Qi; Rui, Yun Feng; Wong, Yin Mei

2012-01-01

77

A biomechanical comparison of patellar tendon repair materials in a bovine model.  

PubMed

We evaluated the biomechanical properties of FiberWire (Arthrex, Inc, Naples, Florida), a new suture material, for both repair and augmentation as compared to standard Ethibond suture (Ethicon, Inc, Somerville, New Jersey), hypothesizing that primary repair and cerclage augmentation with the new suture material would have similar biomechanical properties as a standard repair with wire augmentation. Forty-five fresh bovine knees were placed in 3 groups of equal size: (1) #5 Ethibond tendon repair plus 18-gauge wire augmentation; (2) #5 FiberWire repair plus #5 FiberWire augmentation; and (3) #5 Ethibond repair plus #5 FiberWire augmentation. A straight static pullout test was performed, randomly alternating between the different groups. Gap formation was measured at the center of the repair by a metric ruler, with the examiner blinded to the developing force-tension readout. For each millimeter of gap formation (1-10 mm), the force on the repair was recorded, as well as the force at the ultimate failure of the repair, designated by breakage of any repair material. Analysis showed no significant difference between the standard Ethibond/wire repair and the FiberWire/FiberWire repair. The Ethibond/FiberWire repair was shown to be significantly weaker than the other 2 groups. Ultimate failure data indicated that the Ethibond/wire repair was significantly stronger than both other groups. No significant differences were found between the FiberWire/FiberWire repair and the Ethibond/FiberWire repair. Newer, stronger suture material for both primary repair and augmentation may provide equivalent biomechanical strength at clinically significant levels. PMID:21815574

Flanigan, David C; Bloomfield, Michael; Koh, Jason

2011-08-08

78

Latissimus Dorsi and Teres Major Tears in Professional Baseball PitchersA Case Series  

Microsoft Academic Search

Background: Latissimus dorsi and teres major tendon tears are uncommon injuries. Only a few case reports exist, mainly in high-level athletes.Purpose: To describe a series of latissimus dorsi and teres major tendon tears in professional baseball pitchers.Study Design: Case series; Level of evidence, 4.Methods: Injury data from 3 Major League Baseball clubs were collected over a total of 10 seasons.

Mark S. Schickendantz; Scott G. Kaar; Keith Meister; Pamela Lund; Laurel Beverley

2009-01-01

79

Imaging the infrapatellar tendon in the elite athlete.  

PubMed

Extensor mechanism injuries constitute a major cause of anterior knee pain in the elite athlete. Sonography and magnetic resonance imaging (MRI) are the imaging methods of choice when assessing the infrapatellar tendon. A comprehensive imaging review of infrapatellar tendon normal anatomy, tendinopathy, and partial/full-thickness tendon tears is provided. The value of imaging the infrapatellar tendon in clinical practice, including whether sonography can predict symptoms in asymptomatic athletes, is discussed. Acute avulsion fractures, including periosteal sleeve avulsion, and chronic avulsion injuries, including Sinding-Larsen-Johansson and Osgood-Schlatter syndromes, are shown. Mimics of infrapatellar tendon pathology, including infrapatellar plica injury, patellar tendon-lateral femoral condyle friction syndrome, and Hoffa's syndrome, are illustrated. PMID:16784942

Peace, K A L; Lee, J C; Healy, J

2006-07-01

80

Isokinetic quadriceps and hamstring muscle strength and knee function 5 years after anterior cruciate ligament reconstruction: comparison between bone-patellar tendon-bone and hamstring tendon autografts.  

PubMed

Existing clinical studies have not proven which graft is to be preferred in anterior cruciate ligament (ACL) reconstruction. In recent years, bone-patellar tendon-bone and hamstring tendons have been the most frequently used graft types. Muscle strength deficit is one of the consequences after ACL reconstruction. The aim of this study was to evaluate possible differences in hamstring and quadriceps muscle strength and knee function 5 years after ACL reconstruction between the BPTB and the STG groups. The study group consisted of 288 patients (132 women, 156 men) with a unilateral ACL rupture who had received a BPTB (175 patients) or STG (113 patients) ACL reconstruction. Lower extremity concentric isokinetic peak extension and flexion torques were assessed at the angular velocities of 60 degrees /s and 180 degrees /s. The International Knee Documentation Committee (IKDC), the Tegner activity level, the Lysholm knee and the Kujala patellofemoral scores were also collected. Isokinetic quadriceps peak torque (percentage of the contralateral side) was 3.9% higher in the STG group than in the BPTB group at the velocity of 60 degrees /s and 3.2% higher at the velocity of 180 degrees /s and the isokinetic hamstring peak torque 2% higher in the BPTB group than in the STG group at the velocity of 60 degrees /s and 2.5% higher at the velocity of 180 degrees /s. In both groups the subjects had weaker quadriceps and hamstring muscle strength in the injured extremity compared with the uninjured one. In the single-leg hop test (according to the IKDC recommendations) there was a statistically significant difference (P = 0.040) between the groups. In the STG group, 68% of the patients had the single-leg hop ratio (injured vs. uninjured extremity) > or =90%, 31% of the patients 75-89% and 1% of the patients <75%, while in the BPTB group the corresponding percentages were 72, 21 and 7%. However, no statistically significant differences in clinical outcome were found between the groups as determined by the IKDC, Tegner activity level, Lysholm knee and Kujala patellofemoral scores. PMID:18712355

Lautamies, Riitta; Harilainen, Arsi; Kettunen, Jyrki; Sandelin, Jerker; Kujala, Urho M

2008-08-19

81

Role of metalloproteinases in rotator cuff tear.  

PubMed

The role of matrix metalloproteinases (MMPs) and their inhibitors (TIMPS) in the pathophysiology of rotator cuff tears has not been established yet. Recent advances empathize about the role of MMPs and TIMPS in extracellular matrix (ECM) remodeling and degradation in rotator cuff tears pathogenesis and healing after surgical repair. An increase in MMPs synthesis and the resulting MMPs mediated alterations in the ECM of tendons have been implicated in the etiopathogenesis of tendinopathy, and there is an increase in the expression of MMPs and a decrease in TIMP messenger ribonucleic acid expression in tenocytes from degenerative or ruptured tendons. Importantly, MMPs are amenable to inhibition by cheap, safe, and widely available drugs such as the tetracycline antibiotics and bisphosphonates. A better understanding of relationship and activity of these molecules could provide better strategies to optimize outcomes of rotator cuff therapy. PMID:21822103

Garofalo, Raffaele; Cesari, Eugenio; Vinci, Enzo; Castagna, Alessandro

2011-09-01

82

Stress-induced molecular rearrangement in tendon collagen.  

PubMed

Tension-induced molecular rearrangements in wet native fibres of rat-tail tendons and human finger flexor tendons are registered with the help of time-resolved diffraction spectra using synchrotron radiation. The tension-induced increase of the 67 nm D period is combined with changes in the intensities of some orders of the meridional small angle reflection. Both effects are reversible when unloading the fibre, but are preserved when the load is held constant until the fibre tears. The increase in the D period is partly due to a sliding of the triple helices relative to each other and partly due to a stretching of the triple helices themselves. The sliding of the triple helices results in an alteration of the D stagger, leading to a change in the length of the gap and overlap regions, and to a stretching of the cross-linked telopeptides. This interpretation is supported by comparison with the relative intensities derived from a model with varying length of gap and overlap regions, as well as by comparison with model calculations that include the telopeptides. PMID:4009715

Mosler, E; Folkhard, W; Knörzer, E; Nemetschek-Gansler, H; Nemetschek, T; Koch, M H

1985-04-20

83

Comparison of tear osmolarity and ocular comfort between daily disposable contact lenses: hilafilcon B hydrogel versus narafilcon A silicone hydrogel.  

PubMed

The aim of this study was to evaluate tear osmolarity and ocular comfort with two different types of hydrogel daily disposable lenses. The right eyes of 15 first-time contact lens users were included in this prospective study. All eyes wore hilafilcon B silicone hydrogel contact lenses for 8 h (group 1). After 1 week without contact lenses, all eyes wore narafilcon A silicone hydrogel contact lenses for 8 h (group 2). Tear osmolarity measurement was performed before and after 4 and 8 h of each contact lens wear. Ocular comfort was assessed after 4 and 8 h of each contact lens wear. In group 1, the mean baseline, 4- and 8-h tear osmolarity values were 293 ± 10.57, 303.00 ± 10.5 mOsm/L (p = 0.023), and 295.0 ± 1.4 mOsm/L (p > 0.05), respectively. In group 2, the mean baseline, 4- and 8-h tear osmolarity values were 294 ± 13.65, 300.9 ± 11.3 mOsm/L (p = 0.007), and 298.80 ± 7.2 mOsm/L (p > 0.05), respectively. In group 1, the mean comfort score was 7.20 ± 0.45 and 8.60 ± 0.45 at 4 and 8 h, respectively (p = 0.038). In group 2, the mean comfort score significantly decreased from 9.80 ± 0.45 to 7.80 ± 0.84 at 4 h (p = 0.039). Both hydrogel and silicone hydrogel daily disposable contact lenses elevated tear osmolarity during 8 h of contact lens wear. The increase in tear osmolarity with both contact lenses was below the cut-off value for dry eye and was not associated with ocular comfort. PMID:22484700

Sarac, Ozge; Gurdal, Canan; Bostanc?-Ceran, Basak; Can, Izzet

2012-04-07

84

Blocked tear duct  

MedlinePLUS

... is blocked, the tears will build up and overflow onto the cheek, even when you are not ... The symptom is increased tearing , which overflows onto the face or ... during the first 2 - 3 weeks after birth. Sometimes, the tears ...

85

MR Imaging of the Shoulder: Appearance of the Supraspinatus Tendon in Asymptomatic Volunteers  

Microsoft Academic Search

MR imaging has been shown to be accurate in the diagnosis of rotator cuff disruption and tear. Uncertainty remains about the significance of Increased signal intensity in the critical zone of the supraspinatus tendon without visible disruption of tendon fibers and about the significance of other secondary findings commonly encountered with rotator cuff abnormalities, such as musculotendinous retraction or obliteration

Christian H. Neumann; R. Gary Holt; Lynne S. Steinbach; Anon H. Jahnke; Steve A. Petersen

86

MR assessment of the repaired rotator cuff: prevalence, size, location, and clinical relevance of tendon rerupture  

Microsoft Academic Search

The objectives of this study were to use magnetic resonance (MR) imaging to evaluate the prevalence, size, location, and clinical relevance of tendon rerupture following complete repair of full-thickness rotator cuff tear (RCT). A total of 78 surgically proven full-thickness rotator cuff tears in 74 patients were retrospectively included in the study. Clinical assessment was performed using the University of

J. M. Mellado; J. Calmet; M. Olona; J. Ballabriga; A. Camins; L. Pérez del Palomar; J. Giné

2006-01-01

87

Proximal Humeral Migration in Shoulders with Symptomatic and Asymptomatic Rotator Cuff Tears  

PubMed Central

Background: Proximal humeral migration is commonly seen in rotator-cuff-deficient shoulders. The specific effects of the size of the rotator cuff tear and of pain on glenohumeral kinematics have been poorly defined. The purpose of this study was to examine the influences of cuff tear size and pain, separately, on humeral migration in a series of patients with symptomatic and asymptomatic rotator cuff tears. Methods: Ninety-eight asymptomatic and sixty-two symptomatic shoulders were identified from a cohort of patients with unilateral shoulder pain related to rotator cuff disease. All shoulders underwent ultrasonographic evaluation of the rotator cuff and standardized radiographic evaluation. Humeral migration was measured by three observers using software-enhanced radiographic analysis. Results: There was no significant difference in rotator cuff tear size between the asymptomatic and symptomatic shoulders, although more tears involved the infraspinatus in the symptomatic group (p = 0.01). Proximal humeral migration was greater in the shoulders with a symptomatic tear than it was in those with an asymptomatic tear (p = 0.03). Tears that involved the infraspinatus resulted in more migration than did isolated supraspinatus tears in both the symptomatic (p = 0.01) and the asymptomatic shoulders (p = 0.03). When the symptomatic tears of ?175 mm2 were analyzed separately, the size of the tear was found to correlate strongly with humeral migration (p = 0.01). However, when the symptomatic tears that were <175 mm2 were analyzed, neither tear size nor pain was found to have a significant relationship with migration. When the analysis was limited to full-thickness symptomatic tears of ?175 mm2, both pain (p = 0.002) and tear area (p = 0.0002) were found to have a significant effect on migration. Multivariate analysis showed that tear size (p = 0.01) was the strongest predictor of migration in symptomatic shoulders. Conclusions: Proximal humeral migration correlates with rotator cuff tear size. Tears extending into the infraspinatus tendon are associated with greater humeral migration than is seen with isolated supraspinatus tears. Humeral migration resulting from symptomatic rotator cuff tears is greater than that resulting from asymptomatic tears. Additionally, there is a critical size for tendon tears resulting in humeral migration in painful shoulders. Although both pain and tear size influence glenohumeral kinematics in symptomatic shoulders, only tear size is an independent predictor of humeral migration. Level of Evidence: Prognostic Level II. See Instructions to Authors for a complete description of levels of evidence.

Keener, Jay D.; Wei, Anthony S.; Kim, H. Mike; Steger-May, Karen; Yamaguchi, Ken

2009-01-01

88

[Treatment of acute and chronic peroneal tendon disorders.  

PubMed

Peroneal tendon injuries are recognized with increasing frequency to be the cause of persistent lateral ankle symptoms. The lesions are frequently found in patients with concomitant anatomical or biomechanical abnormalities, such as chronic lateral instability or cavovarus deformity. The most common mechanism involves a sudden inversion injury or repetitive activities. Three categories of injuries can be distinguished: (1) tendinitis and tenosynovitis, (2) tendon subluxation and dislocation and (3) tendon tears and ruptures. Many of these conditions respond to conservative therapy. However, when left untreated, the disorders can lead to persistent lateral ankle pain and substantial functional deficits. This is particularly true in patients with an underlying anatomical predisposition to lesions. PMID:21061115

Knupp, M; Hintermann, B

2010-11-01

89

Arthroscopic repair of full-thicknessrotator cuff tears: Operative technique  

Microsoft Academic Search

Arthroscopic repair of full-thickness rotator cuff tears is currently performed by a number of surgeons. The goals, indications, and postoperative rehabilitation are identical to traditional open repair. The principles of the operative technique are also identical to open repair, with the differences occurring in the manner in which the tendon is repaired to bone. This article describes in detail the

Gary M. Gartsman; Steven M. Hammerman

1998-01-01

90

ACL tear.  

PubMed

Anterior cruciate ligament (ACL) reconstruction has evolved considerably over the past 30 years. This has largely been due to a better understanding of ACL anatomy and in particular a precise description of the femoral and tibial insertions of its two bundles. In the 1980s, the gold standard was anteromedial bundle reconstruction using the middle third of the patellar ligament. Insufficient control of rotational laxity led to the development of double bundle ACL reconstruction. This concept, combined with a growing interest in preservation of the ACL remnant, led in turn to selective reconstruction in partial tears, and more recently to biological reconstruction with ACL remnant conservation. Current ACL reconstruction techniques are not uniform, depending on precise analysis of the type of lesion and the aspect of the ACL remnant in the intercondylar notch. PMID:23333126

Chambat, P

2013-01-16

91

Prospective randomized clinical comparison of femoral transfixation versus bioscrew fixation in hamstring tendon ACL reconstruction—a preliminary report  

Microsoft Academic Search

The purpose of this study is to clinically evaluate hamstring tendon anterior cruciate ligament (ACL)-reconstruction using femoral fixation with bioresorbable interference screws and with a bioresorbable transfixation device. The ACL-reconstruction using the transfixation device at the femoral side leads to less knee laxity and therefore to a better clinical outcome for the patient. Prospective randomized clinical outcome study. From February

Tim Rose; Pierre Hepp; Julia Venus; Christoph Stockmar; Christoph Josten; Helmut Lill

2006-01-01

92

Comparison of anterior cruciate ligament reconstruction in male and female athletes using the patellar tendon and hamstring autografts  

Microsoft Academic Search

Despite the higher incidence of anterior cruciate ligament (ACL) injuries in female than in male athletes few authors have studied the effects of gender on the outcome of ACL reconstruction. This prospective study compared the results of ACL reconstruction using the patellar tendon and hamstring techniques in men and women. We prospectively followed 80 comparable athletes (46 males, 32 females)

Alberto Gobbi; Marcin Domzalski; Jose Pascual

2004-01-01

93

Midterm results and quantitative comparison of postoperative shoulder function in traumatic and non-traumatic rotator cuff tears  

Microsoft Academic Search

IntroductionThe objective of this study was to compare the postoperative range of motion (ROM) and patient satisfaction after surgical reconstruction of traumatic and non-traumatic rotator cuff tears.Materials and methodsThe cases of 46 consecutive patients who underwent the same standardised surgical reconstruction and postoperative rehabilitation protocol between 1993 and 1998 were reviewed. Traumatic (group I, n=20, average age 34.2 years, range 15–49 years)

Carsten Braune; Ruediger von Eisenhart-Rothe; Frederic Welsch; Matthias Teufel; Alwin Jaeger

2003-01-01

94

Meniscus tears that can be left in situ, with or without trephination or synovial abrasion to stimulate healing.  

PubMed

To determine which meniscus tears to leave in situ, the clinician must know whether the meniscus tear is degenerative or nondegenerative, stable or unstable, in an anterior cruciate ligament (ACL)-stable or ACL-unstable knee, and whether it is in the medial or lateral compartment. Symptomatic medial meniscus tears in ACL-intact knees are almost always degenerative in nature and should be removed. Generally, the only type of medial meniscus that can be left in situ is a peripheral, vertical, nondegenerative tear, but these tears are not displaceable, are asymptomatic, and are usually seen in a patient with an ACL tear. In the lateral compartment, most tears can be left in situ and the only tears that need to be repaired are displaceable tears that extend anterior to the popliteus tendon. Although many meniscus repair techniques and fixation devices are available, all factors related to healing and stability should be considered to determine treatment. PMID:22555202

Shelbourne, K Donald; Gray, Tinker

2012-06-01

95

The spherical tearing mode  

Microsoft Academic Search

The spherical tearing mode is the three-dimensional analog of the classical tearing mode in two dimensions. In three dimensions, loops of field lines connecting magnetic nulls play the role of separatrices. A numerical study of the tearing instability of a three-dimensional analytic equilibrium containing a closed spherical tearing surface composed of null-null lines is presented. A new fast tearing instability

S. Hu; A. Bhattacharjee; J. Dorelli; J. M. Greene

2004-01-01

96

Tendon, tendon healing, hyperlipidemia and statins  

PubMed Central

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.

Esenkaya, Irfan; Unay, Koray

2011-01-01

97

Results of the repair of acute rotator cuff tears is not influenced by tear retraction  

PubMed Central

Purpose: This study evaluated retraction in the setting of acute rotator cuff tears and determined its effects on patient outcomes and tendon repair integrity. Materials and Methods: A total of 22 patients had surgery within 6 weeks or less from the time of injury. Fifteen of these patients were prospectively followed at a minimum of 2 years; average 40.5 months (range 24-69). Pre-operative objective and subjective outcomes were compared. Tendon repair integrity was assessed with ultrasound at a minimum of 1 year from surgery. The population was stratified into Group 1 (8 patients) with minimal intra-operative medial tendon retraction to the mid-line level of the humeral head and Group 2 (7 patients) with a large medial tendon retraction to the glenohumeral joint or greater. Results: The average time to surgery from the onset of symptoms was 27 days (range, 6-42). Post-operative motion increased significantly for external rotation and forward elevation, 77% of patients were pain free, 80% were completely satisfied, and 100% would have the surgery again. Group 1 (small retraction) versus Group 2 (large retraction) showed that post-operative pain levels, satisfaction, range of motion, strength, subjective shoulder value (95.4% vs. 92.3%), Constant Score (80.8 vs. 78.1), and American Society of Shoulder and Elbow Surgeons (96.2 vs. 93.5) scores were not statistically different. Ultrasound showed a tendon repair integrity rate of 87%. 2 patients who did have a re-tear were in Group 2, yet had comparative outcomes. Conclusion: In acute rotator cuff tears, equal patient satisfaction, pain scores, range of motion, strength, and outcome measures should be expected with surgical repair despite the level of retraction. Level of Evidence: Therapeutic level IV

Butler, Bryan R.; Byrne, Abigail N.; Higgins, Laurence D.; Shah, Anup; Fowler, Rachel L.

2013-01-01

98

Popliteus tendon tenosynovitis.  

PubMed

This series of case suggests that the entity of tenosynovitis of the popliteus tendon is more common than once recognized. A high index of sucpicion and accurate palpation of the lateral aspect of the knee lead one to the diagnosis. Knowledge of this entity may prevent future misdiagnosis of tear of the lateral meniscus and unnecessary meniscectomy as experienced by Helfet, Holden, and myself. There is a definite correlation with activities requiring downhill walking or running. The runners invariably complained of the oneset of symptoms during downhill running rather than uphill running. Back packing enthusiastscomplained of no symptoms for several days after ascending into the mountains, only to experience the symptoms at the end of a long, rapid descent out of the mountains. The pathomechanics of this inflammation of the popliteus tendon is not fully understood. Preliminary analysis of gait movies suggests that in downhill running there is an increased vector to displace the weight-bearing femur forward on the relatively fixed tibia as the knee is increasingly flexed (Fig. 5). Previously mentioned EMG functional studies indicate that the popliteus muscle is active during this weight-bearing phase of gait and may act to retard the femur from forward displacement on the tibia in conjunction with the quadriceps. More specifically, it may help to retard the lateral femoral condyle from rotating forward off the lateral tibial plateau. Downhill running or walking therefore may cause increased stress on the popliteus muscle-tendon unit in an effort to decelerate the body weight against the altered angle of gravitational pull, with resultant tenosynovitis and symptoms. In this series there were no top flight competitive runners. The typical patient was a 31-year-old physician who was jogging 1 to 5 miles and decided to increase his pace and distance, particularly while jogging downhill. The average age of this series of patients (31 years) at the time of onset, coupled with the fact many of these persons were relatively sedentary until stressing the knee by increased activity, suggests that there will be an increasing number of these patients in the future as jogging and running are prescribed for cardiovascular system conditioning. PMID:848633

Mayfield, G W

99

Intratendinous gouty tophus mimics patellar tendonitis in an athlete.  

PubMed

We describe the imaging and pathologic features of a case of intratendinous patellar gouty tophus incidentally discovered in a patient with knee pain. The possibility of intratendinous gouty tophus must be kept in mind by sports physicians, especially in the management of patellar tendinopathy in athletes. It may be associated with other injuries, such as enthesopathies or partial tendon tears. PMID:22457228

Rodas, Gil; Pedret, Carles; Català, Jordi; Soler, Robert; Orozco, Lluís; Cusi, Manuel

2012-03-27

100

[Diagnosis and treatment of rotator cuff tears].  

PubMed

A rotator cuff tear is a highly prevalent disorder, occurring in 25% of people over 60 years of age. In two thirds of patients the tear is small and asymptomatic. Acute, symptomatic cuff tears may occur in active sportsmen and women aged 30-50. There is often a considerable delay in diagnosis in this group, due to a lack of recognition by either the patient or the doctor. Recently identified risk factors for the development of cuff tear are nicotine abuse, hypercholesterolaemia, contralateral cuff tear and genetic predisposition. Conservative treatment can be very successful and consists of physical therapy and effective analgesics. Repeated steroid injections are harmful to the tendinous tissue and should be avoided. The aim of surgery is anatomical reinsertion of the ruptured tendon using an open or arthroscopic procedure. The arthroscopic procedure enables the surgeon to perform a more extensive evaluation and treatment of the joint. The arthroscopic procedure is technically more demanding than the open procedure, but seems to have a shorter rehabilitation period. PMID:21871139

van der Zwaal, Peer; Pekelharing, Janneke F; Thomassen, Bregje J W; Swen, Jan-Willem A; van Arkel, Ewoud R A

2011-01-01

101

Evaluation of cartilage degeneration in a rat model of rotator cuff tear arthropathy.  

PubMed

BACKGROUND AND HYPOTHESIS: Rotator cuff tears are the most common injury seen by shoulder surgeons. Glenohumeral osteoarthritis develops in many late-stage rotator cuff tear patients as a result of torn cuff tendons, termed "cuff tear arthropathy." However, the mechanisms of cuff tear arthropathy have not been fully established. It has been hypothesized that a combination of synovial and mechanical factors contribute equally to the development of cuff tear arthropathy. The goal of this study was to assess the utility of this model in investigating cuff tear arthropathy. MATERIALS AND METHODS: We used a rat model that accurately reflects rotator cuff muscle degradation after massive rotator cuff tears through either infraspinatus and supraspinatus tenotomy or suprascapular nerve transection. Using a modified Mankin scoring system, we found significant glenohumeral cartilage damage after both rotator cuff tenotomy and suprascapular nerve transection after only 12 weeks. RESULTS: Cartilage degeneration was similar between groups and was present on both the humeral head and the glenoid. Denervation of the supraspinatus and infraspinatus muscles without opening the joint capsule caused cartilage degeneration similar to that found in the tendon transection group. CONCLUSIONS: Our results suggest that altered mechanical loading after rotator cuff tears is the primary factor in cartilage degeneration after rotator cuff tears. Clinically, understanding the process of cartilage degeneration after rotator cuff injury will help guide treatment decisions in the setting of rotator cuff tears. PMID:23664745

Kramer, Erik J; Bodendorfer, Blake M; Laron, Dominique; Wong, Jason; Kim, Hubert T; Liu, Xuhui; Feeley, Brian T

2013-05-01

102

Histopathological, radiographic, and arthrographic comparison of the biceps tendon in normal dogs and dogs with biceps tenosynovitis.  

PubMed

In dogs surgically treated for biceps tenosynovitis, the most common histopathological findings were fibrosis and collagen degeneration (n=13), synovial villous or vascular hyperplasia (n=10), lymphocytic-plasmacytic infiltrates (n=10), cartilaginous metaplasia (n=8), and ischemic necrosis (n=5). Degree of histopathological changes was associated with degree (p equals 0.000), but not duration (p equals 0.543), of lameness. Furthermore, there was no association between histopathological changes and age or radiographic and arthrographic findings. Cartilage metaplasia was the only histopathological finding in both affected tendons (8/18) and normal control dogs (13/13). Age and size of the control dogs were not determined; however, since all these dogs were clinically normal, fibrocartilaginous metaplasia can be present as an incidental finding in the biceps tendon of origin in dogs. PMID:11105890

Davidson, E B; Griffey, S M; Vasseur, P B; Shields, S L

103

Comparison of corneal sensitivity, tear function and corneal staining following laser in situ keratomileusis with two femtosecond laser platforms  

PubMed Central

Purpose To evaluate longitudinal changes in corneal sensitivity, tear function, and corneal staining in patients who underwent laser in situ keratomileusis (LASIK) using two different femtosecond lasers. Methods In a prospective, randomized clinical trial, contralateral eyes of 45 patients underwent flap creation by either VisuMax or IntraLase™ femtosecond laser. Corneal sensitivity, tear break up time (TBUT), Schirmer’s test, and corneal fluorescein staining were assessed preoperatively and at 1 week, 1 month, and 3 months postoperatively. Results There were no statistical differences in any clinical outcome measure between the two femtosecond lasers (P > 0.05), although there was a trend towards slightly lower reductions for corneal sensitivity and TBUT in VisuMax-operated eyes. Overall, corneal sensitivity was significantly reduced at 1 week (P < 0.05), 1 month (P < 0 .001), and 3 months (P < 0.001) postoperatively. A significantly greater reduction of corneal sensitivity was noted in eyes with a myopic spherical equivalent of ?6.00 diopters (D) to ?11.25 D as compared with eyes that had a relatively lower level of myopia of less than ?6.00 D (P < 0.001). TBUT and Schirmer’s test values were significantly diminished at 1 week postoperatively (P < 0.04). Overall, corneal staining was significantly increased at 1 week postoperatively (P < 0.001). The level of myopia did not significantly affect postoperative changes in TBUT, Schirmer’s test values, or corneal staining (P > 0.05). Conclusion This study showed that changes in corneal sensitivity, tear function, and corneal staining were statistically similar in LASIK using VisuMax and IntraLase femtosecond lasers for flap creation. However, the trend towards faster recovery of corneal sensitivity and TBUT observed in VisuMax-operated eyes may be attributable to improved technical specifications.

Petznick, Andrea; Chew, Annabel; Hall, Reece C; Chan, Cordelia ML; Rosman, Mohamad; Tan, Donald; Tong, Louis; Mehta, Jodhbir S

2013-01-01

104

Clinical comparison of freeze-dried and fresh frozen patellar tendon allografts for anterior cruciate ligament reconstruction of the knee  

Microsoft Academic Search

The aim of this study was to evaluate the clinical outcome of freeze-dried compared to fresh frozen al lograft tissue used as a substitute for a ruptured ACL of the knee. In addition, the incidence of any graft rejection phenomena was recorded. Forty-one patients with ACL deficient knees underwent reconstructive sur gery using a patellar bone-tendon-bone allograft that had been

Peter A. Indelicato; Edward S. Bittar; Troy J. Prevot; Gregory A. Woods; Thomas P. Branch; Marty Huegel

1990-01-01

105

Iliopsoas Tendon Reformation after Psoas Tendon Release  

PubMed Central

Internal snapping hip syndrome, or psoas tendonitis, is a recognised cause of nonarthritic hip pain. The majority of patients are treated conservatively; however, occasionally patients require surgical intervention. The two surgical options for iliopsoas tendinopathy are step lengthening of the iliopsoas tendon or releasing the tendon at the lesser trochanter. Although unusual, refractory snapping usually occurs soon after tenotomy. We report a case of a 47-year-old active female with internal snapping and pain following an open psoas tenotomy. Postoperatively she was symptom free for 13 years. An MRI arthrogram revealed reformation of a pseudo iliopsoas tendon reinserting into the lesser trochanter. The pain and snapping resolved after repeat iliopsoas tendon release. Reformation of tendons is an uncommon sequela of tenotomies. However the lack of long-term studies makes it difficult to calculate prevalence rates. Tendon reformation should be included in the differential diagnosis of failed tenotomy procedures after a period of symptom relief.

Garala, K.; Power, R. A.

2013-01-01

106

Recovery of calf muscle strength following acute achilles tendon rupture treatment: a comparison between minimally invasive surgery and conservative treatment.  

PubMed

The aim of this study was to measure the effect of treatment of acute Achilles tendon ruptures on calf muscle strength recovery. Eighty-three patients with acute Achilles tendon rupture were randomly allocated to either minimally invasive surgery with functional after-treatment or conservative treatment by functional bracing. Calf muscle strength using isokinetic testing was evaluated at 3 months and after 6 or more months posttreatment. To exclusively investigate the effect of treatment on outcome, the authors excluded patients with major complications from the analysis. In 31 of 39 patients in the surgical treatment group and 25 of 34 patients in the conservative treatment group, isokinetic strength tests were performed. In the analysis of differences in mean peak torque, no statistically significant differences were found between surgery and conservative treatment, except for plantar flexion strength at 90 degrees per second at the second measurement, favoring conservative treatment. After 8 to 10 months follow- up, loss of plantar flexion strength was still present in the injured leg in both treatment groups. In conclusion, isokinetic muscle strength testing did not detect a statistically significant difference between minimally invasive surgical treatment with functional after-treatment and conservative treatment by functional bracing of acute Achilles tendon ruptures. PMID:19825777

Metz, Roderik; van der Heijden, Geert J M G; Verleisdonk, Egbert-Jan M M; Tamminga, Rob; van der Werken, Christiaan

2009-09-04

107

Oral toxicity of pefloxacin, norfloxacin, ofloxacin and ciprofloxacin: comparison of biomechanical and histopathological effects on Achilles tendon in rats.  

PubMed

Four fluoroquinolones (pefloxacin, norfloxacin, ofloxacin and ciprofloxacin) were compared according to their biomechanical and histopathological effects on rat Achilles tendon. Wistar rats were divided into one untreated control and four treatment groups in parallel. Pefloxacin mesylate dihydrate (40 mg/kg), norfloxacin (40 mg/kg), ofloxacin (20 mg/kg) and ciprofloxacin (50 mg/kg) were administered by gavage twice daily for three consecutive weeks. 6 weeks after treatment, the test animals were euthanised and Achilles tendon specimens were collected. A computer monitored tensile testing machine was utilised for biomechanical testing. The mean elastic modulus of the control group was significantly higher than that of the norfloxacin and pefloxacin groups (p<0.05 and p<0.01, respectively). The mean yield force (YF) of the control group was significantly higher than those of ciprofloxacin, norfloxacin and pefloxacin groups (p<0.001, p<0.05 and p<0.01, respectively). The mean ultimate tensile force (UTF) of the control group was significantly higher than of the ciprofloxacin, norfloxacin, and pefloxacin groups (p<0.001, p<0.05 and p<0.01, respectively). Hyaline degeneration and fibre disarrangement were observed in the tendons of the ciprofloxacin, pefloxacin, and ofloxacin treated-groups, whereas myxomatous degeneration was observed only in the ciprofloxacin and pefloxacin groups. In conclusion, these findings in our rat model reveal significant deterioration of biomechanical parameters following fluoroquinolone exposure, and indicate significantly higher biomechanical toxicity for ciprofloxacin and pefloxacin. PMID:21628961

Olcay, Ercan; Beytemur, Ozan; Kaleagasioglu, Ferda; Gulmez, Turgut; Mutlu, Zihni; Olgac, Vakur

2011-06-01

108

In vivo comparison of biomechanical, histological, and radiological properties of three techniques for tendon lengthening: an experimental study in rabbits.  

PubMed

Biomechanical, histological, and radiological properties of three different techniques of tendon lengthening - Z-plasty, modified Vulpius, and modified Baker - were investigated and compared. Sixty white female Angora rabbits (mean weight 4.1 kg, range 3.9 kg- 4.2 kg) were randomly divided into three groups: Z-plasty, V-Y plasty (modified Vulpius technique), and U-T plasty (modified Baker technique). Histopathological, radiological, and biomechanical properties were evaluated at the third and sixth postoperative week. Qualitative analysis of ultrasound examination showed that Z-plasty had the most irregular echo pattern at the third postoperative week, and had less echogenic areas at the sixth postoperative week. Histological evaluation showed that Z-plasty had significantly more formation of fibrosis and adhesion and less parallel homogeneous collagen fibres at the sixth postoperative week (p<0.05). U-T plasty had a significantly higher mean (SD) failure load (15.35 (1.89) N) than the other two methods during the third postoperative week (p<0.05). There was no significant difference in failure load between the groups at the sixth postoperative week. U-T plasty is a good alternative to Z-plasty technique for lengthening tendons, and it may be the first choice in those who need moderate lengthening of tendons and early rehabilitation because it is easy to do, heals better, and has good biomechanical properties. PMID:19153875

Gideroglu, Kaan; Akan, Mithat; Orhun, Haldun; Bozdag, Ergun; Gül, Aylin Ege; Akgun, Erdal; Akoz, Tayfun

2009-01-01

109

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

PubMed

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

Lui, Tun Hing

2013-09-17

110

Comparison of step-cut and Pulvertaft attachment for flexor tendon graft: a biomechanics evaluation in an in vitro canine model  

PubMed Central

The purpose of this study was to compare two different methods of joining tendons of similar and dissimilar sizes between recipient and donor tendons for flexor tendon grafts. Flexor digitorum profundus (FDP) and peroneus longus (PL) canine tendons were harvested and divided into four groups. The repair technique we compared was a step-cut (SC) suture and a Pulvertaft weave (PW). FDP tendons were significantly larger in diameter than PL tendons (p < 0.05). The volume of the SC repairs using either FDP or PL tendon as a graft was significantly smaller than PW repairs (p < 0.05). The ultimate load to failure and repair stiffness in FDP graft tendons significantly increased compared with the PL graft tendons (p < 0.05). The SC suture can be used as an alternative to the PW, with similar strength and less bulk for repairs using graft tendons of similar diameter. Surgeons should be aware of the effect of graft tendon size and repair method on strength and bulk when performing flexor tendon grafts.

Hashimoto, T; Thoreson, A. R.; An, K.-N.; Amadio, P. C.; Zhao, C.

2013-01-01

111

Arthroscopic repair techniques for massive rotator cuff tears.  

PubMed

Patients with massive rotator cuff tears present with pain, weakness, and loss of function. Candidates for arthroscopic repair include symptomatic, young, active patients; those with an acute tear or tears with early changes of atrophy; and patients willing to comply with recovery and rehabilitation processes after surgery. As massive rotator cuff tears extend, the glenohumeral articulation is destabilized, allowing superior migration. Repair of the force couples and reinforcement of the anterosuperior rotator cuff cable can restore functional elevation via the deltoid. Muscle changes, including rotator cuff atrophy and fatty infiltration, will affect shoulder strength and function. As chronic changes become more extensive (such as the absence of the acromiohumeral interval and degenerative joint changes), other repair options may be more durable. Other arthroscopic options, including partial rotator cuff closure, graft to augment the repair, and use of the long head of the biceps tendon, have been helpful in pain relief and functional gains. PMID:22301227

Abrams, Jeffrey S; Song, Frederick S

2012-01-01

112

Simultaneous acute rotator cuff tear and distal biceps rupture in a strongman competitor.  

PubMed

Acute rotator cuff tear is commonly associated with tearing of the proximal biceps tendon, but has never been reported to occur simultaneously with a distal biceps tendon rupture. A 38-year-old right-hand-dominant strongman competitor attempted a 300-pound overhead axle press and experienced immediate pain in the right shoulder and elbow. He had no known systemic risk factors for tendon ruptures including hyperparathyroidism, hemodialysis, alcoholism, rheumatoid arthritis, statin medications, fluoroquinolones, and steroid use.Right shoulder magnetic resonance imaging (MRI) showed a full-thickness supraspinatus tear with 3 cm of retraction. There was minimal fatty infiltration of the supraspinatus on the sagittal cuts consistent with acute rupture. The subscapularis was intact. The long head of the biceps tendon had mild medial subluxation but was completely within the bicipital groove. Right elbow MRI showed a complete distal biceps tendon rupture. Thirteen days after his injury, the patient underwent arthroscopic supraspinatus repair and proximal biceps tenodesis. Distal biceps tendon repair was performed using the modified 2-incision muscle-splitting technique. At 24-month follow-up, the patient was pain free and had returned to full activity including weightlifting but had not returned to strongman competition.This is the first report of simultaneous acute full thickness ruptures of the rotator cuff and distal biceps tendon. This case report underscores the importance of a complete physical examination and a high index of suspicion for additional concomitant injuries, particularly in athletes with unusually high stresses to the body. PMID:20415310

George, Michael S

2010-04-16

113

Multiple cemental tears.  

PubMed

A cemental tear is a pathologic condition in which a complete or incomplete separation of the cementum occurs along the root surface and is usually accompanied by a deep periodontal pocket. Past articles report that the incidence of cemental tears has usually been limited to 1 tooth per individual. We encountered a clinical case with cemental tears involving 14 teeth in 1 individual. Multiple cemental tears in 1 individual have not been previously described in the dental literature. We present the clinical and pathologic features of this rare case and suggest that the probable cause of multiple cemental tears is structural weakness of the cementum. PMID:22862978

Watanabe, Chie; Watanabe, Yoshihisa; Miyauchi, Mutsumi; Fujita, Minoru; Watanabe, Yoshiyuki

2012-03-05

114

Comparison of Achilles tendon repair techniques in a sheep model using a cross-linked acellular porcine dermal patch and platelet-rich plasma fibrin matrix for augmentation.  

PubMed

The primary goal of this study was to evaluate a cross-linked acellular porcine dermal patch (APD), as well as platelet-rich plasma fibrin matrix (PRPFM), for repair of acute Achilles tendon rupture in a sheep model. The 2 surgically transected tendon ends were reapproximated in groups 1 and 2, whereas a gap was left between the tendon ends in group 3. APD was used to reinforce the repair in group 2, and autologous PRPFM was used to fill the gap, which was also reinforced with APD, in group 3. All sheep were humanely euthanized at 24 weeks after the repair, and biomechanical and histological testing were performed. Tensile strength testing showed a statistically significant difference in elongation between the operated limb and the unoperated contralateral limb in groups 1 and 3, but not in group 2. All operated tendons appeared healed with no apparent fibrosis under light and polarized microscopy. In group 1, all surgical separation sites were identifiable, and healing occurred via increasing tendon thickness. In group 2, healing occurred with new tendon fibers across the separation, without increasing tendon thickness in 2 out of 6 animals. Group 3 showed complete bridging of the gap, with no change in tendon thickness in 2 out of 6 animals. In groups 2 and 3, peripheral integration of the APD to tendon fibers was observed. These findings support the use of APD, alone or with PRPFM, to augment Achilles tendon repair in a sheep model. PMID:20137980

Sarrafian, Tiffany L; Wang, Hali; Hackett, Eileen S; Yao, Jian Q; Shih, Mei-Shu; Ramsay, Heather L; Turner, A Simon

2010-02-04

115

Achilles tendon rupture - aftercare  

MedlinePLUS

The Achilles tendon connects your calf muscles to your heel bone. Together, they help you push your heel off the ... your toes. You use these muscles and your Achilles tendon when you walk, run, and jump. If your ...

116

Musculoskeletal diseases--tendon  

PubMed Central

Introduction Tendons establish specific connections between muscles and the skeleton by transferring contraction forces from skeletal muscle to bone thereby allowing body movement. Tendon physiology and pathology are heavily dependent on mechanical stimuli. Tendon injuries clinically represent a serious and still unresolved problem since damaged tendon tissues heal very slowly and no surgical treatment can restore a damaged tendon to its normal structural integrity and mechanical strength. Understanding how mechanical stimuli regulate tendon tissue homeostasis and regeneration will improve the treatment of adult tendon injuries that still pose a great challenge in today's medicine. Source of data This review summarizes the current status of tendon treatment and discusses new directions from the point of view of cell-based therapy and regenerative medicine approach. We searched the available literature using PubMed for relevant original articles and reviews. Growing points Identification of tendon cell markers has enabled us to study precisely tendon healing and homeostasis. Clinically, tissue engineering for tendon injuries is an emerging technology comprising elements from the fields of cellular source, scaffold materials, growth factors/cytokines and gene delivering systems. Areas timely for developing research The clinical settings to establish appropriate microenvironment for injured tendons with the combination of these novel cellular- and molecular-based scaffolds will be critical for the treatment.

Sakabe, Tomoya; Sakai, Takao

2011-01-01

117

Shielding of augmented tendon-tendon repair  

Microsoft Academic Search

Strength and function of autogenic and xenogenic reconstruction of digital extensor tendons was examined in an ovine model. In this study, tendon-graft junctions were formed by either suture augmented with a woven polyester tube (A), or augmented and shielded from surrounding tissues by chemically-treated bovine pericardium (S). By 12 wk, both A and S sheep had returned to full range

G. J. Rogers; B. K. Milthorpe; K. Schindhelm; C. R. Howlett; S. Roe

1995-01-01

118

[Lower limb dysaesthesia after anterior cruciate ligament reconstructions with hamstring tendons. A comparison of vertical versus oblique harvest site incisions].  

PubMed

The purpose of this retrospective study was to compare early lower limb dysaesthesia after anterior cruciate ligament (ACL) reconstructions. The procedures were performed with ST and GR tendons using vertical or oblique harvest site incisions. In the year 2006 52 patients were treated due to total ACL rupture. In 35 we performed vertical harvest site incision and in 17 oblique incision were performed. Average follow-up was 1 month. At this time patients were asked to draw any dysaesthesia area on a knee diagram, if present. In the vertical harvest site incision 31 patients had dysaesthesia about the knee, and the average dysaesthesia area was 46.8 cm2. In the oblique harvest site incision 15 patients had dysaesthesia about the knee and the average dysaesthesia area was 44.3 cm2. The dysaesthesia areas were mostly of ellipse-like shape. There was no signigicant difference between two groups. PMID:18078276

Kaczmarczyk, Jacek; Sergiew, Marcin; Adamcewicz, Filip; Kruczy?ski, Jacek

119

Shoulder Joint Tear (Glenoid Labrum Tear)  

MedlinePLUS

... can occur from acute trauma or repetitive shoulder motion. Examples of traumatic injury include: Falling on an ... labrum tears as a result of repetitive shoulder motion. Top of page Symptoms The symptoms of a ...

120

A comparison of accuracy between clinical examination and magnetic resonance imaging in the diagnosis of meniscal and anterior cruciate ligament tears  

Microsoft Academic Search

A prospective and retrospective study was undertaken to compare the accuracy of magnetic resonance imaging (MRI) with clinical examination in diagnosing meniscal and anterior cruciate ligament (ACL) tears. Pathological findings were then confirmed during arthroscopy. One hundred fifty-four patients clinically diagnosed with a meniscal or ACL tear who ultimately had arthroscopic knee surgery were evaluated; 100 patients underwent clinical examination

Nicholas E. Rose; Stuart M. Gold

1996-01-01

121

Achilles tendinopathy and partial tear diagnosis using dual-energy computed tomography collagen material decomposition application.  

PubMed

Computed tomographic (CT) scans of the ankle and foot are frequently obtained with in-patients with hind foot and ankle pain to identify fractures, arthritis, and bone lesions. Soft tissue detail is limited, however. Dual-energy CT provides additional information on soft tissue structures, including tendons, with no additional radiation dose to the patient. We present a case of an Achilles tendon tear visualized on DECT, which was subsequently confirmed with magnetic resonance imaging. PMID:23674025

Mallinson, Paul I; Stevens, Chris; Reisinger, Clemens; Nicolaou, Savvas; Munk, Peter L; Ouellette, Hugue

122

Tibial fixation comparison of semitendinosus-bone composite allografts fixed with bioabsorbable screws and bone-patella tendon-bone grafts fixed with titanium screws.  

PubMed

Tibial fixation remains the weak link of ACL reconstruction over the first 8-12 weeks postoperatively. This study compared the biomechanical properties of tibial fixation for a bone-patellar tendon-bone (BPTB) graft and a novel semitendinosus-bone composite (SBC) allograft with mixed cortical-cancellous bone dowels at each end. Seven paired, fresh frozen cadaveric knees (20-45 years) were stripped of all soft tissue attachments and randomly assigned to receive either the BPTB graft or SBC allograft. Grafts were placed into tibial tunnels via a standard protocol and secured with either a 10 mmx28 mm bioabsorbable (SBC) or titanium (BPTB) screw. Grafts were cycled ten times in a servo hydraulic device from 10-50 N prior to pull to failure testing at a rate of 20 mm/min with the force vector aligned with the tibial tunnel ("worst case scenario"). Wilcoxon Signed Rank Tests were used to evaluate biomechanical differences between graft types ( p<0.05). Tibial bone mineral density and interference screw insertion torque were statistically equivalent between graft types. The mode of failure for all constructs was direct screw and graft construct pullout from the tibial tunnel. Significant differences were not observed between graft types for maximum load at failure strength (BPTB=620.8+/-209 N vs. SBC=601.2+/-140 N, p=0.74) or stiffness (BPTB=69.8 N/mm+/-29 N/mm vs SBC=47.1+/-31.6 N/mm, p=0.24). The SBC allograft yielded significantly more displacement prior to failure than the BPTB graft (15.1+/-4.9 mm vs 9.2+/-1.3 mm, p=0.04). Increased construct displacement appeared to be due to fixation failure, with some evidence of graft tissue tearing around the sutures: Bioabsorbable screw (10 x 28 mm) fixation of the SBC allograft produced unacceptable displacement levels during testing. Further study is recommended using a titanium interference screw or a longer bioabsorbable screw for SBC graft fixation under cyclic loading conditions. PMID:12845425

Kocabey, Y; Klein, S; Nyland, J; Caborn, D

2003-07-04

123

Tendon repair and healing.  

PubMed

Tendon connects muscle to bone and functions to transmit muscular forces across joints to stabilize or move those joints. Tendons in the foot and ankle are subject to enormous loads and consequently make up a substantial portion of the body's tendon injuries. Understanding the mechanisms of these injuries requires an understanding of the relative rates of muscle, tendon, osteotendinous junction, and myotendinous junction adaptation. This article provides the practitioner with an overview of tendon anatomy, physiology, healing, and repair and correlates didactic and clinical aspects so that practitioners can better treat patients and get them back to normal functioning as quickly and as close to anatomic and physiologic capabilities as possible. PMID:16213379

Platt, Marc A

2005-10-01

124

Rotator cuff tears: assessment with MR arthrography in 275 patients with arthroscopic correlation  

Microsoft Academic Search

We assessed the diagnostic performance of magnetic resonance (MR) arthrography in the diagnosis of articular-sided partial-thickness\\u000a and full-thickness rotator cuff tears in a large symptomatic population. MR arthrograms obtained in 275 patients including\\u000a a study group of 139 patients with rotator cuff tears proved by arthroscopy and a control group of 136 patients with arthroscopically\\u000a intact rotator cuff tendons were

S. Waldt; M. Bruegel; D. Mueller; K. Holzapfel; A. B. Imhoff; E. J. Rummeny; K. Woertler

2007-01-01

125

Characterization of fluoroquinolone-induced Achilles tendon toxicity in rats: comparison of toxicities of 10 fluoroquinolones and effects of anti-inflammatory compounds.  

PubMed Central

Fluoroquinolone antibacterial agents have been reported to induce tendon lesions in juvenile rats. In the present study, we characterized fluoroquinolone-induced Achilles tendon lesions by comparing the effects of 10 fluoroquinolones and examining the potential of one of these antimicrobial agents, pefloxacin, to induce tendon lesions when coadministered with one of nine anti-inflammatory compounds. Among the 10 fluoroquinolones tested, fleroxacin and pefloxacin were the most toxic, inducing lesions at a dose of 100 mg/kg of body weight or more, while lomefloxacin, levofloxacin, and ofloxacin or sparfloxacin and enoxacin induced lesions at 300 mg/kg or more and 900 mg/kg, respectively. In contrast, norfloxacin, ciprofloxacin, and tosufloxacin had no effect even at the high dose of 900 mg/kg. The severity of the Achilles tendon lesions appeared to correlate with the structure of the substituent at the seventh position. Furthermore, pefloxacin-induced tendon lesions were inhibited by coadministration with dexamethasone and N-nitro-L-arginine methyl ester. Phenidone (1-phenyl-3-pyrazolidinone) and 2-(12-hydroxydodeca-5,10-diynyl)3,5,6-trimethyl-1,4-benzoqui none (AA861) also decreased the incidence of tendon lesions. In contrast, catalase, dimethyl sulfoxide, indomethacin, pyrilamine, and cimetidine did not modify these tendon lesions. These results suggest that nitric oxide and 5-lipoxigenase products partly mediate fluoroquinolone-induced tendon lesions.

Kashida, Y; Kato, M

1997-01-01

126

Recruitment viscoelasticity of the tendon.  

PubMed

There is still no agreement on the nature of tissues' viscoelasticity and on its reliable modeling. We speculate that disagreements between previous observations stem from difficulties of separating between viscoelastic and preconditioning effects, since both are manifested by similar response features. Here, this and related issues were studied in the tendon as a prototype for other soft tissues. Sheep digital tendons were preconditioned under strain that was higher by 1% than the one used in subsequent testing. Each specimen was then subjected to stress relaxation, and quick release or creep. A stochastic microstructural viscoelastic theory was developed based on the collagen fibers' properties and on their gradual recruitment with stretch. Model parameters were estimated from stress relaxation data and predictions were compared with the creep data. Following its validation, the new recruitment viscoelasticity (RVE) model was compared, both theoretically and experimentally, with the quasilinear viscoelastic (QLV) theory. The applied preconditioning protocol produced subsequent pure viscoelastic response. The proposed RVE model provided excellent fit to both stress relaxation and creep data. Both analytical and numerical comparisons showed that the new RVE theory and the popular QLV one are equivalent under deformation schemes at which no fibers buckle. Otherwise, the equivalence breaks down; QLV may predict negative stress, in contrast to data of the quick release tests, while RVE predicts no such negative stress. The results are consistent with the following conclusions: (1) fully preconditioned tendon exhibits pure viscoelastic response, (2) nonlinearity of the tendon viscoelasticity is induced by gradual recruitment of its fibers, (3) a new structure-based RVE theory is a reliable representation of the tendon viscoelastic properties under both stress relaxation and creep tests, and (4) the QLV theory is equivalent to the RVE one (and valid) only under deformations in which no fibers buckle. The results also suggest that the collagen fibers themselves are linear viscoelastic. PMID:20353259

Einat, Raz; Yoram, Lanir

2009-11-01

127

The Use of an Intra-Articular Depth Guide in the Measurement of Partial Thickness Rotator Cuff Tears  

PubMed Central

Purpose. The purpose of this study was to compare the accuracy of the conventional method for determining the percentage of partial thickness rotator cuff tears to a method using an intra-articular depth guide. The clinical utility of the intra-articular depth guide was also examined. Methods. Partial rotator cuff tears were created in cadaveric shoulders. Exposed footprint, total tendon thickness, and percentage of tendon thickness torn were determined using both techniques. The results from the conventional and intra-articular depth guide methods were correlated with the true anatomic measurements. Thirty-two patients were evaluated in the clinical study. Results. Estimates of total tendon thickness (r = 0.41, P = 0.31) or percentage of thickness tears (r = 0.67, P = 0.07) using the conventional method did not correlate well with true tendon thickness. Using the intra-articular depth guide, estimates of exposed footprint (r = 0.92, P = 0.001), total tendon thickness (r = 0.96, P = 0.0001), and percentage of tendon thickness torn (r = 0.88, P = 0.004) correlated with true anatomic measurements. Seven of 32 patients had their treatment plan altered based on the measurements made by the intra-articular depth guide. Conclusions. The intra-articular depth guide appeared to better correlate with true anatomic measurements. It may be useful during the evaluation and development of treatment plans for partial thickness articular surface rotator cuff tears.

Carroll, Michael J.; More, Kristie D.; Sohmer, Stephen; Nelson, Atiba A.; Sciore, Paul; Boorman, Richard; Hollinshead, Robert; Lo, Ian K. Y.

2013-01-01

128

Blocked Tear Duct  

MedlinePLUS

... cancer treatment. If you've had radiation or chemotherapy to treat cancer, particularly if the radiation was focused on your face or head, you're at higher risk of developing a blocked tear duct. Complications Because your tears aren't draining the way ...

129

Tears and Their Secretion  

Microsoft Academic Search

The exposed surface of the eye is continuously covered by a thin film of fluid, the tear film, which covers the entire ocular surface, including the cornea (the clear “window” of the eye) and conjunctiva (the white part of the eye, which extends under the eyelid). The tear film is a complex fluid that is secreted by several different glands

Darlene A. Dartt; Robin R. Hodges; Driss Zoukhri

2005-01-01

130

Surgical technique for repair of acute proximal hamstring tears.  

PubMed

The surgical technique for repair of acute proximal hamstring tears is relatively recent. Installation of the patient is critical. The approach is either vertical under the gluteal fold in case of a complete tear with tendon retraction of more than 6 cm, or horizontal in the gluteal fold for retraction of less than 6 cm or for partial tears. After identification and neurolysis of the sciatic nerve, transosseous tendon reinsertion is performed with three or four metal or resorbable suture anchors. A rigid brace keeping the leg at 30° of flexion is worn for few days, then replaced by an articulated knee brace for 45 days, which limits extension but allows full flexion. Rehabilitation is begun early. Thirty-four patients underwent surgery for acute proximal hamstring tear and received this treatment. All of the athletic patients were able to return to their pre-injury activities after a mean 5.7 ± 1.6 months (2.3-9.3 months). PMID:22926295

Lefevre, N; Bohu, Y; Klouche, S; Herman, S

2012-08-25

131

Partial-Thickness Rotator Cuff Tears  

PubMed Central

Although the incidence of partial-thickness rotator cuff tears (PTRCTs) was reported to be from 13% to 32% in cadaveric studies, the actual incidence is not yet known. The causes of PTRCTs can be explained by either extrinsic or intrinsic theories. Studies suggest that intrinsic degeneration within the rotator cuff is the principal factor in the pathogenesis of rotator cuff tears. Extrinsic causes include subacromial impingement, acute traumatic events, and repetitive microtrauma. However, acromially initiated rotator cuff pathology does not occur and extrinsic impingement does not cause pathology on the articular side of the tendon. An arthroscopic classification system has been developed based on the location and depth of the tear. These include the articular, bursal, and intratendinous areas. Both ultrasound and magnetic resonance image are reported with a high accuracy of 87%. Conservative treatment, such as subacromial or intra-articular injections and suprascapular nerve block with or without block of the articular branches of the circumflex nerve, should be considered prior to operative treatment for PTRCTs.

2011-01-01

132

Riser and tendon management system  

SciTech Connect

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.

Devlin, P.V.

1992-02-18

133

Tendon and ligament imaging  

PubMed Central

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.

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

2012-01-01

134

Biomimetic Scaffold Design for Functional and Integrative Tendon Repair  

PubMed Central

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.

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

2012-01-01

135

Biomimetic scaffold design for functional and integrative tendon repair.  

PubMed

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 underscores the clinical need for alternative grafting solutions. The 2 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 discussion of future directions. PMID:22244070

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

2012-02-01

136

The relevance of long head biceps degeneration in the presence of rotator cuff tears  

Microsoft Academic Search

BACKGROUND: Long head biceps (LHB) degeneration in combination with rotator cuff tears can be a source of chronic shoulder pain. LHB tenotomy is an approved surgical procedure for pain reduction and improvement of joint function, however, the pathophysiology of LHB degeneration is not fully understood. In the literature, neoangiogenesis in tendon tissue has previously been shown to be associated with

Stefan Lakemeier; Johannes JA Reichelt; Nina Timmesfeld; Susanne Fuchs-Winkelmann; Juergen RJ Paletta; Markus D Schofer

2010-01-01

137

Glenoid cartilage mechanical properties decrease after rotator cuff tears in a rat model.  

PubMed

Rotator cuff repairs are commonly performed to reduce pain and restore function. Tears are also treated successfully without surgical intervention; however, the effect that a torn tendon has on the glenohumeral cartilage remains unknown. Clinically, a correlation between massive rotator cuff tears and glenohumeral arthritis has often been observed. This may be due to a disruption in the balance of forces at the shoulder, resulting in migration of the humeral head and subsequently, abnormal loading of the glenoid. Our lab previously demonstrated changes in ambulation and intact tendon mechanical properties following supraspinatus and infraspinatus rotator cuff tendon tears in a rat model. Therefore, the purpose of this study was to investigate the effects of supraspinatus and infraspinatus rotator cuff tears on the glenoid cartilage. Nine rats underwent unilateral detachment of the supraspinatus and infraspinatus tendons and were sacrificed after 4 weeks. Cartilage thickness significantly decreased in the antero-inferior region of injured shoulders. In addition, equilibrium elastic modulus significantly decreased in the center, antero-superior, antero-inferior, and superior regions. These results suggest that altered loading after rotator cuff injury may lead to damage to the joint with significant pain and dysfunction. Clinically, understanding the mechanical processes involved with joint damage will allow physicians to better advise patients. PMID:22407524

Reuther, Katherine E; Sarver, Joseph J; Schultz, Susan M; Lee, Chang Soo; Sehgal, Chandra M; Glaser, David L; Soslowsky, Louis J

2012-03-09

138

The Spherical Tearing Mode  

NASA Astrophysics Data System (ADS)

While our understanding of resistive tearing modes in two-dimensional magnetic configurations is quite complete, relatively little is known is known about the geometry and dynamics of tearing modes in truly three-dimensional magnetic configurations like the Earth's magnetosphere. We present new results on the spherical tearing mode, which is the three dimensional generalization of the classical tearing mode first discovered by Furth, Killeen, and Rosenbluth (FKR). In this model, loops of field lines connecting magnetic nulls play the role of X-lines lines in two-dimensional slab geometry. In the initial equilibrium, a closed spherical surface composed of null-null lines separates an inner region of closed field lines from an outer region of open field lines. A new fast tearing instability of this three-dimensional equilibrium, which contains a closed spherical separatrix composed of null-null lines, is identified. The instability growth rate scales as S-1/4, where S is the Lundquist number, and is thus significantly faster than the FKR tearing mode. The spherical tearing surface breaks up, enabling the closed field lines to break and reconnect with open field lines. The new geometry thus realized is relevant to the type of 3D magnetic geometries realized in global 3D MHD codes in which reconnection is usually forced by the solar wind. Implications for 3D reconnection in the Earth's magnetosphere will be discussed.

Bhattacharjee, A.; Dorelli, J.; Raeder, J.

2004-05-01

139

An Artificial Tendon with Durable Muscle Interface  

PubMed Central

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.

Melvin, Alan; Litsky, Alan; Mayerson, Joel; Witte, David; Melvin, David; Juncosa-Melvin, Natalia

2010-01-01

140

Physical Therapist's Guide to Rotator Cuff Tear  

MedlinePLUS

... bring with you to your health care provider. Longo UG, Franceschi F, Berton A, et al. Conservative treatment and rotator cuff tear progression. Med Sport Sci . 2012;57:90–99. Article Summary on PubMed . Düzgün I, Baltac? G, Atay OA. Comparison of slow and accelerated rehabilitation ...

141

The tibialis posterior tendon  

PubMed Central

The tibialis posterior tendon is the largest and anteriormost tendon in the medial ankle. It produces plantar flexion and supination of the ankle and stabilizes the plantar vault. Sonographic assessment of this tendon is done with high-frequency, linear-array transducers; an optimal examination requires transverse retromalleolar, longitudinal retromalleolar, and distal longitudinal scans, as well as dynamic studies. Disorders of the posterior tibial tendon include chronic tendinopathy with progressive rupture, tenosynovitis, acute rupture, dislocation and instability, enthesopathies. The most common lesion is a progressive “chewing gum” lesion that develops in a setting of chronic tendinopathy; it is usually seen in overweight women over 50 years of age with valgus flat feet. Medial ankle pain must also be carefully investigated, and the presence of instability assessed with dynamic maneuvers (forced inversion, or dorsiflexion) of the foot. Sonography plays an important role in the investigation of disorders involving the posterior tibial tendon.

Lhoste-Trouilloud, A.

2012-01-01

142

Acellular Flexor Tendon Allografts: A New Horizon for Tendon Reconstruction.  

PubMed

Flexor tendon injuries continue to pose a significant challenge to the hand surgeon. In particular, chronic tendon ruptures with adhesions of the tendons and sheath, damage or loss of the intrasynovial flexor tendons in zone II, and combined soft tissue and bone injuries present especially difficult problems for restoring satisfactory digital function. This challenge in flexor tendon reconstruction has motivated hand surgeons to explore and develop novel solutions for nearly a century. Recent advances and techniques in processing and decellularizing allograft human flexor tendon constructs may prove to be a new horizon for tendon reconstruction. PMID:23707595

Drake, David B; Tilt, Alexandra C; Degeorge, Brent R

2013-05-24

143

[Contribution of MRI to the preoperative evaluation of rotator cuff tears].  

PubMed

The authors report a series of 38 patients who had been examined by MRI and then operated for a rotator cuff syndrome. The correlation between the description of the cuff lesions after MRI and the surgical observations were excellent for 37 patients. In one case MRI showed a false image of tear of the supra spinatus m. on its anterior edge. This was due to a bad knowledge of the anatomy of the muscle and tendon and to a poor orientation of the frontal cut plane. This study was completed with MRI and anatomic study of 12 non embalmed cadaveric shoulders. The results showed that MRI was very sensitive (0.93) and specific (0.94) for the diagnosis of rotator cuff tears. MRI allowed also to show partial tears of the tendons of the rotator cuff. The authors propose a MRI classification of cuff lesions which permits to establish a good surgical planning. PMID:1812516

Gagey, N; Desmoineaux, P; Gagey, O; Idy-Peretti, I; Mazas, F

1991-01-01

144

The Spherical Tearing Mode  

NASA Astrophysics Data System (ADS)

We present new results on the spherical tearing mode, which is the three dimensional generalization of the classical tearing mode for toroidal devices with closed field lines. In this model, loops of field lines connecting magnetic nulls play the role of closed field lines in toroidal geometry. In the initial equilibrium, a closed spherical surface composed of null-null lines separates a region containing closed field lines from a region of open field lines. The instability growth rate scales as S-1/4, where S is the Lundquist number, and is thus faster than the classical tearing mode. The spherical tearing surface breaks up, enabling the closed field lines to break and reconnect with open field lines. The new geometry thus realized is relevant to the type of 3D magnetospheric geometries seen in global 3D MHD codes in which reconnection is usually forced by the solar wind. Implications for observations of reconnection at the dayside magnetopause will be discussed.

Bhattacharjee, A.; Dorelli, J.; Greene, J. M.; Hu, S.

2004-11-01

145

Hip Labral Tear  

MedlinePLUS

... a hip labral tear: Overuse. People who participate in sports or other activities that require repeated twisting or ... injuries, and hip arthroscopy in the athlete. Clinics in Sports Medicine. 2006;25:279. Kovacevic D, et al. ...

146

Magnetic resonance imaging of the elbow. Part II: Abnormalities of the ligaments, tendons, and nerves  

Microsoft Academic Search

Part II of this comprehensive review on magnetic resonance imaging of the elbow discusses the role of magnetic resonance imaging in evaluating patients with abnormalities of the ligaments, tendons, and nerves of the elbow. Magnetic resonance imaging can yield high-quality multiplanar images which are useful in evaluating the soft tissue structures of the elbow. Magnetic resonance imaging can detect tears

Richard Kijowski; Michael Tuite; Matthew Sanford

2005-01-01

147

Tears at the rotator cuff footprint: Prevalence and imaging characteristics in 305 MR arthrograms of the shoulder  

Microsoft Academic Search

Objectives  To evaluate the prevalence, imaging characteristics and anatomical distribution of tears at the rotator cuff (RC) footprint\\u000a with MR arthrography (MR-A) of the shoulder.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  MR arthrograms obtained in 305 patients were retrospectively reviewed. Partial articular-sided supraspinatus tendon avulsions\\u000a (PASTA), concealed interstitial delaminations (CID), reverse PASTA lesions and full-thickness tears (FT) at the humeral tendon\\u000a insertion were depicted. Anatomical locations were

Christoph Schaeffeler; Dirk Mueller; Chlodwig Kirchhoff; Petra Wolf; Ernst J. Rummeny; Klaus Woertler

2011-01-01

148

CREEP RUPTURE OF WALLABY TAIL TENDONS  

Microsoft Academic Search

The tail tendons from wallabies ( Macropus rufogriseus) suffer creep rupture at stresses of 10 MPa or above, whereas their yield stress in a dynamic test is about 144 MPa. At stresses between 20 and 80 MPa, the time-to- rupture decreases exponentially with stress, but at 10 MPa, the lifetime is well above this exponential. For comparison, the stress on

XIAO TONG WANG; ROBERT F. KER

149

Tendon gradient mineralization for tendon to bone interface integration.  

PubMed

Tendon-to-bone integration is a great challenge for tendon or ligament reconstruction regardless of use of autograft or allograft tendons. We mineralized the tendon, thus transforming the tendon-to-bone into a "bone-to-bone" interface for healing. Sixty dog flexor digitorum profundus (FDP) tendons were divided randomly into five groups: (1) normal FDP tendon, (2) CaP (non-extraction and mineralization without fetuin), (3) CaPEXT (Extraction by Na2 HPO4 and mineralization without fetuin), (4) CaPFetuin (non-extraction and mineralization with fetuin), and (5) CaPEXTFetuin (extraction and mineralization with fetuin). The calcium and phosphate content significantly increased in tendons treated with combination of extraction and fetuin compared to the other treatments. Histology also revealed a dense mineral deposition throughout the tendon outer layers and penetrated into the tendon to a depth of 200?µm in a graded manner. Compressive moduli were significantly lower in the four mineralized groups compared with normal control group. No significant differences in maximum failure strength or stiffness were found in the suture pull-out test among all groups. Mineralization of tendon alters the interface from tendon to bone into mineralized tendon to bone, which may facilitate tendon-to-bone junction healing following tendon or ligament reconstruction. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31:1713-1719, 2013. PMID:23939935

Qu, Jin; Thoreson, Andrew R; Chen, Qingshan; An, Kai-Nan; Amadio, Peter C; Zhao, Chunfeng

2013-08-12

150

Tendinopathy of the tendon of the long head of the biceps.  

PubMed

Pathologies of tendon of the long head of the biceps (LHB) are an important cause of shoulder pain. They include tendinopathy, rupture, superior labrum anterior and posterior lesions, pulley tears, and tendon instability. Conservative management of symptomatic LHB tendinopathy is commonly accepted as the first-line treatment. It consists of rest, nonsteroidal anti-inflammatory drugs, corticosteroid injections, and physical therapy. Biceps tenotomy and tenodesis are the most common surgical procedures to manage both isolated LHB pathology and biceps-glenoid complex tears combined with rotator cuff tears. However, controversy persists about the superiority of one of them because there is no evidence of significant differences in functional scores or patient satisfaction between the 2 techniques. This article provides an overview on biomechanical function of the LHB and current strategies for treatment of LHB disorders. PMID:22089281

Longo, Umile Giuseppe; Loppini, Mattia; Marineo, Gianluca; Khan, Wasim S; Maffulli, Nicola; Denaro, Vincenzo

2011-12-01

151

Risk factors associated with anal sphincter tear: A comparison of primiparous patients, vaginal births after cesarean deliveries, and patients with previous vaginal delivery  

Microsoft Academic Search

Objective: This study was conducted to identify obstetric risk factors for anal sphincter tear in primiparous patients, patients with a previous cesarean delivery (VBAC), and patients with a previous vaginal delivery (PVD). Study Design: An obstetrics automated record system was accessed to retrospectively review records of all singleton vaginal deliveries at greater than 36 weeks' gestation (excluding breech and stillbirth)

Holly E. Richter; Cynthia G. Brumfield; Suzanne P. Cliver; Kathryn L. Burgio; Cherry L. Neely; R. Edward Varner

2002-01-01

152

Human tears contain a chemosignal.  

PubMed

Emotional tearing is a poorly understood behavior that is considered uniquely human. In mice, tears serve as a chemosignal. We therefore hypothesized that human tears may similarly serve a chemosignaling function. We found that merely sniffing negative-emotion-related odorless tears obtained from women donors induced reductions in sexual appeal attributed by men to pictures of women's faces. Moreover, after sniffing such tears, men experienced reduced self-rated sexual arousal, reduced physiological measures of arousal, and reduced levels of testosterone. Finally, functional magnetic resonance imaging revealed that sniffing women's tears selectively reduced activity in brain substrates of sexual arousal in men. PMID:21212322

Gelstein, Shani; Yeshurun, Yaara; Rozenkrantz, Liron; Shushan, Sagit; Frumin, Idan; Roth, Yehudah; Sobel, Noam

2011-01-06

153

Rotator cuff repair with periosteum for enhancing tendon–bone healing: a biomechanical and histological study in rabbits  

Microsoft Academic Search

During rotator cuff repair surgery, fixation and incorporation of ruptured rotator cuff tendon into the bone is a major concern.\\u000a The repair usually fails at the tendon–bone interface, especially in cases where the tear is massive. The periosteum contains\\u000a multipotent stem cells that have the potential to differentiate into osteogenic and chondrogenic tissues, which may restore\\u000a the original structure at

Chih-Hsiang Chang; Chih-Hwa Chen; Chun-Yi Su; Hsien-Tao Liu; Chung-Ming Yu

2009-01-01

154

Identification, quantification and comparison of major non-polar lipids in normal and dry eye tear lipidomes by electrospray tandem mass spectrometry  

PubMed Central

Millions of individuals suffer from a health condition known as keratoconjunctivitis sicca (KCS, also known as ‘dry eye’). Studies have indicated that the lipids in the tear film layer, which covers the outer portion of the eye, may be directly correlated with the existence of dry eye syndrome. By identifying and comparing the major, non-polar lipids in normal eye tears with a dry eye model, it may be possible to identify a symptom of, or a contributing factor to, dry eye. Electrospray tandem mass spectrometry (ES-MS/MS) was used to identify and compare the non-polar lipids, detected as lithium adducts, from normal and dry eye tear samples obtained from rabbits. A limited number of normal human tear samples were also examined for lipid content, and a close resemblance to rabbit was observed. Three distinct regions were delineated in the ES mass spectra of the non polar lipids, m/z 20–500, 500–800 and 800–1100. A common feature noted among identified lipid components was a glycerol backbone with fatty acyl substituents attached. Product ion spectra were obtained for lithiated monoacyl-, 1,2- and 1,3-diacyl- and triacylglyceride standards. Newly proposed structures and fragmentation pathways for the major product ions are presented for the 1,2- and 1,3-diglycerides, and also for the monoglyceride. New approaches to distinguishing asymmetric 1,2-diglycerides and 1,2- from 1,3-diglycerides are proposed. For the rabbit tear samples, the m/z 20–500 range contains monoester diols with empirical formulas CnH2nO4, the m/z 500–800 range includes diesters with empirical formulas CnH2n?2O5 and the m/z 800–1100 range contains triesters with empirical formulas CnH2n?4O6. Also found in the extracts were three isoprene acetals (terpenoids).

Ham, Bryan M.; Jacob, Jean T.; Keese, Monica M.; Cole, Richard B.

2008-01-01

155

The tendons: Interventional sonography  

PubMed Central

While blind or fluoroscopically guided infiltration works well for intra-articular injections, injections into the tendon sheath are much more difficult. Ultrasound guidance with high-frequency transducers now allows visualization and infiltration of tendon sheaths. The interventional phase should be preceded by a diagnostic scan. Patients should be questioned to identify possible contraindications to the procedure and informed of the potential risks. Strict asepsis must be maintained for both patient and operator. This review includes separate discussions of the tendons in different areas of the body that are most commonly treated with ultrasound-guided injections, with descriptions of the lesions that are treated and the approach used for each. Interventional sonography is currently the only technique that allows visualization of the tendon being infiltrated. It requires training and experience as well as good knowledge of the indications and equipment used for the procedures, and the anatomy of the areas being treated.

Campagna, R.; Guerini, H.

2012-01-01

156

Achilles Tendon Rupture  

MedlinePLUS

... recreational sports. Achilles tendon injuries occur more often in sports that involve running, jumping and sudden starts and ... may also need to consult with doctors specializing in sports medicine or orthopedic surgery. What you can do ...

157

Measurement of stress strain and vibrational properties of tendons  

NASA Astrophysics Data System (ADS)

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.

Revel, Gian Marco; Scalise, Alessandro; Scalise, Lorenzo

2003-08-01

158

Common Disorders of the Achilles Tendon  

MedlinePLUS

... Text Size Print Bookmark Common Disorders of the Achilles Tendon What Is the Achilles Tendon? A tendon is a band of tissue that connects a muscle to a bone. The Achilles tendon runs down the back of the lower leg ...

159

A comparison of techniques for fixation of the quadriceps muscle–tendon complex for in vitro biomechanical testing of the knee joint in sheep  

Microsoft Academic Search

Whilst in vitro testing can contribute to a better understanding of the biomechanical interactions at the knee joint, the application of physiological-like muscle forces in vitro remains challenging. One main difficulty seems to be the adequate fixation of the muscle–tendon complex to the mechanical apparatus that provides the forces in vitro. The goal of this study was to compare the

Philip Schöttle; Ioannis Goudakos; Nikolaus Rosenstiel; Jan-Erik Hoffmann; William R. Taylor; Georg N. Duda; Markus O. Heller

2009-01-01

160

Comparison of the holding capacity of round monofilament, round multifilament, and flat multifilament nitinol suture loops in human cadaveric flexor tendon.  

PubMed

Tendon repairs done with strong suture materials fail by suture pull out. To avoid pull out, suture loop needs to have a strong grip on the tendon. The aim of this study was to determine whether a single suture loop has a better grip of the tendon when multifilament or flat sutures are used compared with a conventional monofilament round suture. A cross-locking or simple grasping suture loop was placed into the distal end of a human cadaveric tendon using nitinol wire sutures in the following configurations: round monofilament (200 µm), round multifilament (4 × 100 µm), and flat multifilament (4 × 30 µm × 445 µm). The mean pull-out strength of the round multifilament (49.4 N) and flat multifilament sutures (50.7 N) were significantly higher than that of the round monofilament nitinol suture (36.5 N) when a locking loop was used. Suture grip can be improved by using a multifilament suture and a locking type of suture configuration. PMID:22117009

Karjalainen, T; He, M; Chong, A K S; Lim, A Y T; Göransson, H; Ryhänen, J

2011-11-24

161

Management of tendon disorders in cattle.  

PubMed

This article describes tendon disorders in cattle and treatments for such disorders. Tendon injuries causing loss of a production animal or a decreased level of production result in significant economic loss to the cattle producer. Tendon disorders may be congenital or acquired. Congenital abnormalities may include tendon laxity, contracted tendons, or tendon displacement. Acquired tendon disorders may include tendon laxity, contracture, luxation, tendinitis, laceration, avulsion, rupture, and tenosynovitis. PMID:18929961

Anderson, David E; Desrochers, André; St Jean, Guy

2008-11-01

162

New Solution for Massive, Irreparable Rotator Cuff Tears: The Subacromial "Biodegradable Spacer"  

PubMed Central

Massive, irreparable rotator cuff tears are a source of pain and disability. Although most rotator cuff tears can be completely repaired, a significant number are considered massive and irreparable. Numerous operative techniques have been described for the treatment of these kinds of tears including arthroscopic debridement, biceps tenotomy, tendon transfer, grafting, and reverse arthroplasty. We describe a surgical technique using a biodegradable subacromial balloon spacer (InSpace; OrthoSpace, Kfar Saba, Israel) implanted between the humeral head and acromion that permits smooth, frictionless gliding, restoring the shoulder biomechanics. The technique is easy to perform and is less invasive than the conventional surgical techniques available, and it may potentially serve as a bridging option in patients with massive, irreparable tears who are normally candidates for reverse arthroplasty.

Savarese, Eugenio; Romeo, Rocco

2012-01-01

163

Operative management of partial- and full-thickness rotator cuff tears.  

PubMed

Repair of rotator cuff tears (RCT) is challenging. In RC tears, a partial (PTRCTs) or full (RCTs) discontinuation of one or more of the muscles or tendons and may occur as a result of traumatic injury or degeneration over a period of years. Many factors seem to contribute to the final outcome and a considerable number of variations during the decision-making process of patients with RCTs exist. Accurate diagnosis is fundamental to guide correct management, and the tear pattern should be carefully evaluated to plan the appropriate repair. Both non-operative and operative treatments are used to relieve pain and restore movement and function of the shoulder. Different surgical options are available. The present review describes the current evidence about diagnosis and management of partial and complete rotator tears. PMID:21986049

Franceschi, Francesco; Papalia, Rocco; Palumbo, Alessio; Del Buono, Angelo; Maffulli, Nicola; Denaro, Vincenzo

2011-10-04

164

[Repair of Achilles tendon rupture and early rehabilitation].  

PubMed

The frequency of Achilles tendon tear has increased worldwide. Several factors have been described that help explain the mechanism of injury. The treatment of choice continues to be surgery; conservative treatment is reserved for patients with a high morbidity and mortality. Surgical treatment consists of an open or percutaneous technique. In both modalities we try to achieve prompt mobilization of the operated tendon to obtain better and quicker healing. This prospective study describes our experience with 35 patients enrolled from February 2004 to August 2010. They were treated with open repair, physical rehabilitation and active ankle mobilization before the second postoperative week, and with colchicine. We obtained satisfactory results. Patients recovered complete mobility approximately at postoperative week 6, and from weeks 8 to 10 they could resume their daily work activities and participate in sports and recreational activities. Patients were assessed according to the ATRS classification to measure their clinical results. We had no infections or other major complications. We conclude that the open surgical repair of Achilles tendon tear, prompt mobility, and colchicine provide good results. PMID:23323299

Delgado-Brambila, H A; Cristiani, D G; Tinajero, E C; Burgos-Elías, V

165

Fibrocartilage in tendons and ligaments -- an adaptation to compressive load  

PubMed Central

Where tendons and ligaments are subject to compression, they are frequently fibrocartilaginous. This occurs at 2 principal sites: where tendons (and sometimes ligaments) wrap around bony or fibrous pulleys, and in the region where they attach to bone, i.e. at their entheses. Wrap-around tendons are most characteristic of the limbs and are commonly wider at their point of bony contact so that the pressure is reduced. The most fibrocartilaginous tendons are heavily loaded and permanently bent around their pulleys. There is often pronounced interweaving of collagen fibres that prevents the tendons from splaying apart under compression. The fibrocartilage can be located within fascicles, or in endo- or epitenon (where it may protect blood vessels from compression or allow fascicles to slide). Fibrocartilage cells are commonly packed with intermediate filaments which could be involved in transducing mechanical load. The ECM often contains aggrecan which allows the tendon to imbibe water and withstand compression. Type II collagen may also be present, particularly in tendons that are heavily loaded. Fibrocartilage is a dynamic tissue that disappears when the tendons are rerouted surgically and can be maintained in vitro when discs of tendon are compressed. Finite element analyses provide a good correlation between its distribution and levels of compressive stress, but at some locations fibrocartilage is a sign of pathology. Enthesis fibrocartilage is most typical of tendons or ligaments that attach to the epiphyses of long bones where it may also be accompanied by sesamoid and periosteal fibrocartilages. It is characteristic of sites where the angle of attachment changes throughout the range of joint movement and it reduces wear and tear by dissipating stress concentration at the bony interface. There is a good correlation between the distribution of fibrocartilage within an enthesis and the levels of compressive stress. The complex interlocking between calcified fibrocartilage and bone contributes to the mechanical strength of the enthesis and cartilage-like molecules (e.g. aggrecan and type II collagen) in the ECM contribute to its ability to withstand compression. Pathological changes are common and are known as enthesopathies.

BENJAMIN, M.; RALPHS, J. R.

1998-01-01

166

Surgical approach to acute pectoralis major tendon rupture.  

PubMed

Pectoralis major rupture is a very uncommon injury first time described by Patissier in 1822. Tears are classified on the type (partial and complete) or on the site (tendinous, myotendinous junction, intramuscular). Ruptures are reported in young high-performance athletes as results of eccentric contractions of the musculotendinous unit. The most probable mechanism in elderly patients is a brisk tearing movement applied to stiff atrophic muscle. Injuries generally involve the sternal portion; the localization to the clavicular portion is rare and can be misdiagnosed as muscle sprain. Preoperative planning include MRI as gold standard regarding operative versus non operative treatment decisions. Surgical repair is recommended in cases of complete tears because of loss of strenght in adduction, flexion and internal rotation. Aim of the current study is to describe the surgical repair of acute pectoralis major tendon rupture in 5 patients. Surgery was performed through a modified delto-pectoral approach; pectoralis major tendon was attached at its anatomic insertion using two metallic anchors. The patient as been immobilized in a sling for 30 days and then assisted physiotherapy begun; strenght exercises were allowed at 90 days. At a mean follow-up of 24 months results were excellent in all cases with restoration of strenght and coming back to previously sports activity. PMID:19272235

Merolla, G; Campi, F; Paladini, P; Porcellini, G

167

The influence of radiofrequency ablation patterns on length, histological and mechanical properties of tendons  

PubMed Central

Summary The use of radiofrequency ablation for thermomodulation of connective tissues has gained acceptance with some surgeons. It is now mainly used for shoulder instability, and two techniques are commonly applied – ablation in a uniform pattern (paintbrush) and ablation in a linearly dispersed fashion (grid). The use of these techniques for shrinkage of tendons or cruciate ligaments is not widely accepted but may be utilized in selected cases. We assessed the effects of thermo-modulation via monopolar radiofrequency ablation using these two techniques on the histological and biomechanical properties of rabbit Achilles tendons. 16 paired rabbit achilles tendons were divided into two treatment groups. Using a Monopolar RF device, eight tendons were treated using the paintbrush technique, and eight using the grid technique. The tendons were shrunk to about 90% of their original length, and the paired tendons were used as control. Following thermomodulation, tendons were pulled to tear using the Instron 4502 (Instron, Mass.) device. We found treated tendons were significantly less resistant to tear when compared to control; the average load to failure of the treatment group was 19.4% lower (p=0.05) than the control group values and the average tissue stiffness in the treatment group was 11.3% lower (p=0.051) than the control group. We found a tendency towards a lower resistance to pull in the tendon group treated using the grid technique. Histological analysis demonstrated areas of collagen denaturation correlated to areas of thermomodulation. A random point of failure was found along the tendons in the paintbrush group whereas the typical point of failure in the grid group was located at the treatment point or at its margins. Our findings demonstrate that use of the grid technique in ablation of tendons creates typical failure points (locus minoris resistenci) which bring about failure and alter the biomechanical properties of the thermomodulated tendons. Thermomodulation of tendons may be used efficiently in selected cases but its detrimental effects to the biomechanical attributes of the tissue should be considered.

Oron, Amir; Reshef, Noam; Beer, Yiftah; Brosh, Tamar; Agar, Gabriel

2012-01-01

168

Operative reconstruction after transverse rupture of the tendons of both peroneus longus and brevis. Surgical reconstruction by transfer of the flexor digitorum longus tendon.  

PubMed

Rupture of the tendons of both peroneus longus and peroneus brevis results in considerable disability. We have performed transfer of flexor digitorum longus (FDL) to peroneus brevis in two patients with lateral instability of the hindfoot due to chronic transverse tears of both tendons for which end-to-end repair was not possible. Both patients had excellent function when reviewed after eight and six years, respectively, with no symptoms. CT showed a normal appearance of the FDL in both patients, but the peroneal muscles looked abnormal. Transfer of the FDL provides a reliable solution to lateral instability of the hindfoot resulting from loss of function of both peronei. PMID:9768886

Borton, D C; Lucas, P; Jomha, N M; Cross, M J; Slater, K

1998-09-01

169

[Achilles tendon rupture].  

PubMed

The treatment of acute of Achilles tendon rupture experienced a dynamic development in the last ten years. Decisive for this development was the application of MRI and above all the ultrasonography in the diagnostics of the pathological changes and injuries of tendons. The question of rupture morphology as well as different courses of healing could be now evaluated objectively. These advances led consequently to new modalities in treatment concepts and rehabilitation protocols. The decisive input for improvements of the outcome results and particularly the shortening of the rehabilitation period came with introduction of the early functional treatment in contrast to immobilizing plaster treatment. In a prospective randomized study (1987-1989) at the Trauma Dept. of the Hannover Medical School could show no statistical differences comparing functional non-operative with functional operative therapy with a special therapy boot (Variostabil/Adidas). The crucial criteria for therapy selection results from the sonographically measured position of the tendon stumps in plantar flexion (20 degrees). With complete adaptation of the tendons' ends surgical treatment does not achieve better results than non-operative functional treatment in term of tendon healing and functional outcome. Regarding the current therapeutic standards each method has is advantages and disadvantages. Both, the operative and non-operative functional treatment enable a stable tendon healing with a low risk of re-rupture (1-2%). Meanwhile there is consensus for early functional after-treatment of the operated Achilles' tendons. There seems to be a trend towards non-operative functional treatment in cases of adequate sonographical findings, or to minimal invasive surgical techniques. PMID:10798233

Thermann, H; Hüfner, T; Tscherne, H

2000-03-01

170

Latissimus dorsi transfer for treatment of irreparable rotator cuff tears.  

PubMed

Massive rotator cuff tendon ruptures are not uncommon in older patients. We propose the transfer of the latissimus dorsi muscle for treatment of irreparable ruptures associated with functional impairment and chronic pain. Five women and 11 men were so treated and reviewed with an average follow-up of 26 months. The mean age was 60 years. Four patients also had subscapularis deficiency. Results were assessed with the Constant score and the Oxford shoulder score. Humeral head position was analysed. Statistical analysis was performed by the Wilcoxon non-parametrical test. The Constant score increased by 24.2% (p?=?0.001) with all parameters showing improvement. Nine patients showed improved humeral head positioning in internal rotation. Three of four patients with a deficient subscapularis had unfavourable results. Latissimus dorsi transfer for the treatment of irreparable massive rotator cuff tears leads to a substantial clinical improvement. An intact subscapularis tendon is mandatory. PMID:20155494

Weening, Alexander A; Willems, W Jaap

2010-02-16

171

Rotator Cuff Tear Pain and Tear Size and Scapulohumeral Rhythm  

PubMed Central

Context: The body of knowledge concerning shoulder kinematics in patients with rotator cuff tears is increasing. However, the level of understanding regarding how pain and tear size affect these kinematic patterns is minimal. Objective: To identify relationships between pain associated with a full-thickness rotator cuff tear, tear size, and scapulohumeral rhythm (SHR) and to determine whether pain and tear size serve as predictors of SHR. Design: A test-retest design was used to quantify pain and SHR before and after a subacromial lidocaine injection. Correlation and multivariate analyses were used to identify relationships among pain, tear size, and SHR. Setting: Orthopaedic biomechanics research laboratory. Patients or Other Participants: Fifteen patients (age range, 40–75 years) with diagnosed full-thickness rotator cuff tears participated. They were experiencing pain at the time of testing. Intervention(s): Shoulder kinematic data were collected with an electromagnetic tracking system before and after the patient received a lidocaine injection. Main Outcome Measure(s): Pain was rated using a visual analog scale. Three-dimensional scapular kinematics and glenohumeral elevation were assessed. Scapular kinematics included anterior-posterior tilt, medial-lateral tilt, and upward-downward rotation. A regression model was used to calculate SHR (scapular kinematics to glenohumeral elevation) for phases of humeral elevation and lowering. Results: Linear relationships were identified between initial pain scores and SHR and between tear size and SHR, representing an increased reliance on scapular motion with increasing pain and tear size. Pain was identified as an independent predictor of SHR, whereas significant findings for the effect of tear size on SHR and the interaction between pain and tear size were limited. Conclusions: We noted an increased reliance on scapular contributions to overall humeral elevation with increasing levels of pain and rotator cuff tear size. Pain associated with a rotator cuff tear serves as a primary contributor to the kinematic patterns exhibited in patients with rotator cuff tears.

Scibek, Jason S; Carpenter, James E; Hughes, Richard E

2009-01-01

172

Tears of Wine  

ERIC Educational Resources Information Center

The unique occurrence of the upward motion of a thin film of wine, and its formation into drops inside the wall of a wine glass is explained. Evaporation of alcohol generates a surface tension gradient, moving the film of wine upwards on the internal sides of a wine glass, where it collects and forms into drops or tears.

Gugliotti, Marcos

2004-01-01

173

Tears of Wine  

ERIC Educational Resources Information Center

|The unique occurrence of the upward motion of a thin film of wine, and its formation into drops inside the wall of a wine glass is explained. Evaporation of alcohol generates a surface tension gradient, moving the film of wine upwards on the internal sides of a wine glass, where it collects and forms into drops or tears.|

Gugliotti, Marcos

2004-01-01

174

Integrated Approach for Prediction of Hot Tearing  

NASA Astrophysics Data System (ADS)

Shrinkage, imposed strain rate, and (lack of) feeding are considered the main factors that determine cavity formation or the formation of hot tears. A hot-tearing model is proposed that will combine a macroscopic description of the casting process and a microscopic model. The micromodel predicts whether porosity will form or a hot tear will develop. Results for an Al-4.5 pct Cu alloy are presented as a function of the constant strain rate and cooling rate. Also, incorporation of the model in a finite element method (FEM) simulation of the direct-chill (DC) casting process is reported. The model shows features well known from literature such as increasing hot-tearing sensitivity with increasing deformation rate, cooling rate, and grain size. Similar trends are found for the porosity formation as well. The model also predicts a beneficial effect of applying a ramping procedure during the start-up phase, which is an improvement in comparison with earlier findings obtained with alternative models. In principle, the model does not contain adjustable parameters, but several parameters are not well known. A full quantitative validation not only requires detailed casting trials but also independent determination of some thermophysical parameters of the semisolid mush.

Suyitno; Kool, W. H.; Katgerman, L.

2009-10-01

175

Neuronal regulation of tendon homoeostasis.  

PubMed

The regulation of tendon homoeostasis, including adaptation to loading, is still not fully understood. Accumulating data, however, demonstrates that in addition to afferent (sensory) functions, the nervous system, via efferent pathways which are associated with through specific neuronal mediators plays an active role in regulating pain, inflammation and tendon homeostasis. This neuronal regulation of intact-, healing- and tendinopathic tendons has been shown to be mediated by three major groups of molecules including opioid, autonomic and excitatory glutamatergic neuroregulators. In intact healthy tendons the neuromediators are found in the surrounding structures: paratenon, endotenon and epitenon, whereas the proper tendon itself is practically devoid of neurovascular supply. This neuroanatomy reflects that normal tendon homoeostasis is regulated from the tendon surroundings. After injury and during tendon repair, however, there is extensive nerve ingrowth into the tendon proper, followed by a time-dependent emergence of sensory, autonomic and glutamatergic mediators, which amplify and fine-tune inflammation and regulate tendon regeneration. In tendinopathic condition, excessive and protracted presence of sensory and glutamatergic neuromediators has been identified, suggesting involvement in inflammatory, nociceptive and hypertrophic (degenerative) tissue responses. Under experimental and clinical conditions of impaired (e.g. diabetes) as well as excessive (e.g. tendinopathy) neuromediator release, dysfunctional tendon homoeostasis develops resulting in chronic pain and gradual degeneration. Thus there is a prospect that in the future pharmacotherapy and tissue engineering approaches targeting neuronal mediators and their receptors may prove to be effective therapies for painful, degenerative and traumatic tendon disorders. PMID:23718724

Ackermann, Paul W

2013-05-30

176

Principles of arthroscopic repair of large and massive rotator cuff tears.  

PubMed

Minimally invasive arthroscopic techniques for rotator cuff tears have been greatly advanced during the past decade. It is important to review the clinical presentation and common physical findings of a large or massive rotator cuff tear, essential preoperative imaging, and the principles and technical aspects of all-arthroscopic repair. An anatomic repair of the footprint must begin with an understanding of the three-dimensional morphology of the rotator cuff tear and an accurate reduction of the tear. A contracted, immobile massive rotator cuff tear is challenging. Advanced arthroscopic mobilization techniques and margin convergence principles may allow repair of an otherwise irreparable tear. Failure of tendon healing is common but can be minimized by using dual-row, transosseous-equivalent techniques. A relatively slow rehabilitation program is paramount to protect the repair. The result of using arthroscopic techniques for a large or massive rotator cuff tear is comparable to that of a traditional open repair. Pain relief has been a far more reliable result than gains in function or strength. PMID:20415385

MacDonald, Peter B; Altamimi, Sahal

2010-01-01

177

A prospective comparison of bone-patellar tendon-bone and hamstring grafts for anterior cruciate ligament reconstruction in female patients  

Microsoft Academic Search

The aim of the study is to compare the results after arthroscopic anterior cruciate ligament (ACL) reconstruction using central-third, bone-patellar tendon-bone (BTB group) (n=28) and four-strand semitendinosus\\/gracilis (ST\\/G group) (n=31) autografts in female patients. The type of study was non-randomised prospective consecutive series. A consecutive series of 61 female patients, all with unilateral ACL ruptures, was included in the study.

Michael Svensson; Ninni Sernert; Lars Ejerhed; Jon Karlsson; Jüri T. Kartus

2006-01-01

178

ACL Reconstruction with Autologous Hamstring Tendon: Comparison of Short Term Clinical Results between Rigid-fix and PINN-ACL Cross Pin  

PubMed Central

Purpose To compare the short term clinical results of anterior cruciate ligament (ACL) reconstruction with autologous hamstring tendon between Rigid-fix and PINN-ACL Cross Pin for femoral side fixation. Materials and Methods 127 patients who underwent arthroscopic ACL reconstruction using autologous hamstring tendon and had been followedup for over than one year were enrolled for the present study. Rigid-fix was used in 71 cases (group 1), and PINN-ACL Cross Pin was used in 56 cases (group 2). Clinical and radiological results, operation time, and perioperative complications were compared amongst the two groups. Results The International Knee Documentation Committee subjective score and Lysholm score were 94 and 95 in group 1 and 87 and 91 in group 2, with no statistical difference (p=0.892, p=0.833), respectively. However, significant difference was observed in one-leg hop test between the two groups (p=0.032). Five cases in group 1 and 40 cases in group 2 were found to be associated with perioperative complications with statistical difference (p<0.0001). Conclusions There was no resultant difference between the employment of PINN-ACL Cross Pin and Rigid-fix as femoral graft fixation for ACL reconstruction with hamstring tendon. However, PINN-ACL Cross Pin led to complications with extensive operation times. Hence, it needs further improvement of tools for minimization of complications.

Seo, Seung-Suk; Nam, Tae-Seok; Choi, Sang-Yeong

2011-01-01

179

Tendon injuries in dance.  

PubMed

Professional ballet dancers require an extraordinary anatomic, physiologic, and psychologic makeup to achieve and sustain their level of ability and activity. They are subject to a myriad of injuries as a result of the extreme demands of this profession. Tendon injuries are common and often coexist with other pathologies of the bone, ligaments, and psyche. It is critical that the dance doctor not examine the tendon injury in isolation, but rather the cause of the injury, either intrinsic from anatomic malalignment or from external sources, including poor form. PMID:18346542

Hodgkins, Christopher W; Kennedy, John G; O'Loughlin, Padhraigh F

2008-04-01

180

Autologous tenocyte implantation, a novel treatment for partial-thickness rotator cuff tear and tendinopathy in an elite athlete.  

PubMed

Tendinopathy and small partial-thickness tears of the rotator cuff tendon are common presentations in sports medicine. No promising treatment has yet been established. Corticosteroid injections may improve symptoms in the short term but do not primarily treat the tendon pathology. Ultrasound-guided autologous tenocyte implantation (ATI) is a novel bioengineered treatment approach for treating tendinopathy. We report the first clinical case of ATI in a 20-year-old elite gymnast with a rotator cuff tendon injury. The patient presented with 12 months of increasing pain during gymnastics being unable to perform most skills. At 1 year after ATI the patient reported substantial improvement of clinical symptoms. Pretreatment and follow-up MRIs were reported and scored independently by two experienced musculoskeletal radiologists. Tendinopathy was improved and the partial-thickness tear healed on 3 T MRI. The patient was able to return to national-level competition. PMID:23314880

Wang, Allan W; Bauer, Stefan; Goonatillake, Matthew; Breidahl, William; Zheng, Ming-Hao

2013-01-11

181

Arthroscopically Assisted Semitendinosus and Gracilis Tendon Graft in Reconstruction for Acute Anterior Cruciate Ligament Injuries in Athletes  

Microsoft Academic Search

We evaluated 69 arthroscopically assisted anterior cru ciate ligament reconstructions for acute tears at an average followup of 60 months. We used a distally based single semitendinosus and gracilis tendon graft passed over the top and fixed to the femur. Combined medial collateral ligament lesions were seen in 30 knees, and they were repaired when found in the distal third

Paolo Aglietti; Roberto Buzzi; Pier Paolo M. Menchetti; Francesco Giron

1996-01-01

182

Outlet biceps tenodesis: a new technique for treatment of biceps long head tendon injury.  

PubMed

Degeneration and tearing of the long head of the biceps brachii tendon (LHBT) are common intra-articular findings, and surgical intervention including tenodesis or tenotomy is beneficial. A new arthroscopic shoulder technique may be performed through an anterior portal while one is viewing from a posterior portal: (1) Visualize the intra-articular biceps tendon. (2) Identify the segment of the LHBT to be enlarged. (3) Use a tissue modulation wand to enlarge the tendon. (4) Evaluate the diameter of the enlarged segment. It should be twice the original diameter. (5) Cut the biceps tendon at the proximal end of the enlarged segment. (6) View the tendon within the tunnel. (7) Identify and cut the remaining stump of the biceps tendon. Seventeen cadaveric shoulders were used to compare the pullout force, stiffness, and displacement of outlet tenodesis versus tenotomy. There was a significant increase in pullout force for the outlet tenodesis group when compared with tenotomy. This technique is used to operatively treat LHBT intra-articular pathology in patients who would benefit from tenotomy and traditional biceps tenodesis and may minimize the retraction of the biceps tendon distally. PMID:23875155

Lemos, David; Esquivel, Amanda; Duncan, Douglas; Marsh, Stephanie; Lemos, Stephen

2013-03-17

183

Molecular targets for tendon neoformation  

PubMed Central

Tendons and ligaments are unique forms of connective tissue that are considered an integral part of the musculoskeletal system. The ultimate function of tendon is to connect muscles to bones and to conduct the forces generated by muscle contraction into movements of the joints, whereas ligaments connect bone to bone and provide joint stabilization. Unfortunately, the almost acellular and collagen I–rich structure of tendons and ligaments makes them very poorly regenerating tissues. Injured tendons and ligaments are considered a major clinical challenge in orthopedic and sports medicine. This Review discusses the several factors that might serve as molecular targets that upon activation can enhance or lead to tendon neoformation.

Aslan, Hadi; Kimelman-Bleich, Nadav; Pelled, Gadi; Gazit, Dan

2008-01-01

184

Comparison of viscoelastic, structural, and material properties of double-looped anterior cruciate ligament grafts made from bovine digital extensor and human hamstring tendons.  

PubMed

Due to ready availability, decreased cost, and freedom from transmissible diseases in humans such as hepatitis and AIDS, it would be advantageous to use tendon grafts from farm animals as a substitute for human tendon grafts in in vitro experiments aimed at improving the outcome of anterior cruciate ligament (ACL) reconstructive surgery. Thus the objective of this study was to determine whether an anterior cruciate ligament (ACL) graft composed of two loops of bovine common digital extensor tendon has the same viscoelastic, structural, and material properties as a graft composed of a double loop of semitendinosus and gracilis tendons from humans. To satisfy this objective, grafts were constructed from each tissue source. The cross-sectional area was measured using an area micrometer, and each graft was then pulled using a materials testing system while submerged in a saline bath. Using two groups of tendon grafts (n = 10), viscoelastic tests were conducted over a three-day period during which a constant displacement load relaxation test was followed by a constant amplitude, cyclic load creep test (first day), a constant load creep test (second day), and an incremental cyclic load creep test (third day). Load-to-failure tests were performed on two different groups of grafts (n = 8). When the viscoelastic behavior was compared, there were no significant differences in the rate of load decay or the final load (relaxation test) and rates of displacement increase or final displacements (creep tests) (p > 0.115). To compare both the structural and material properties in the toe region (i.e., < 250 N) of the load-elongation curve, the tangent stiffness and modulus functions were computed from parameters used in an exponential model fit to the load (stress)-elongation (strain) data. Although one of the two parameters in the functions was different statistically, this difference translated into a difference of only 0.03 mm in displacement at 250 N of load. In the linear region (i.e., 50-75 percent of ultimate load) of the load-elongation curve, the linear stiffness of the two graft types compared closely (444 N/mm for bovine and 418 N/mm for human) (p = 0.341). At failure, the ultimate loads (2901 N and 2914 N for bovine and human, respectively) and the ultimate stresses (71.8 MPa and 65.6 MPa for bovine and human, respectively) were not significantly different (p > 0.261). The theoretical effect of any differences in properties between these two grafts on the results of two types of in vitro experiments (i.e., effect of surgical variables on knee laxity and structural properties of fixation devices) are discussed. Despite some statistical differences in the properties evaluated, these differences do not translate into important effects on the dependent variables of interest in the experiments. Thus the bovine tendon graft can be substituted for the human tendon graft in both types of experiments. PMID:11340877

Donahue, T L; Gregersen, C; Hull, M L; Howell, S M

2001-04-01

185

Pele's tears and spheres  

NASA Astrophysics Data System (ADS)

Pele's tears are a well known curiosity commonly associated with low viscosity basaltic explosive eruptions. However, these pyroclasts are rarely studied in detail and there is no full explanation for their formation. These intriguing pyroclasts have smooth glassy surfaces, vesiculated interiors, and fluidal morphologies tending towards droplets and then spheres as they decrease in size to <2 mm. We present a detailed characterisation of Pele's tears from the 1959 fire-fountaining eruption of Kilauea Iki involving size and density measurements. Using thin section and SEM analysis we also consider their internal and external morphologies, porosity and bubble size distributions, and surface textures. Finally we consider the mechanisms of magma fragmentation, timescales of relaxation, and cooling rates that are responsible for their formation.

Porritt, L. A.; Quane, S.; Russell, K.

2011-12-01

186

Flexor tendon surgery. Part 2: Free tendon grafts and tenolysis.  

PubMed

We have attempted to review the development and current status of flexor tendon surgery. The methods of acute flexor tendon repair, conventional free tendon grafting, staged flexor tendon reconstruction, tenolysis and pulley restoration have been discussed, with the published results included for each procedure. The role of rehabilitation has also been reviewed and the ongoing quest for an active flexor tendon prosthetic implant has been briefly mentioned. It may be seen that flexor tendon surgery is a complex and difficult art which requires a thorough appreciation of the normal flexor tendon system, the exact status of that system following injury and surgery and a strong understanding of the techniques which may be best utilised to restore tendon gliding and digital joint motion. The procedures described require both technical skill and experience and the post-operative therapy programmes must be carefully chosen for each patient. With the important laboratory and clinical advancements occurring in many areas of flexor tendon surgery, it is realistic to believe that in the future the techniques described here will be substantially altered and modified and to hope that results will continue to improve until the patient and surgeon can expect to restore most digits to nearly full function after flexor tendon interruption. PMID:2695588

Strickland, J W

1989-11-01

187

Long Head of the Biceps Pathology Combined with Rotator Cuff Tears  

PubMed Central

The long head of the biceps tendon (LHBT) is an anatomic structure commonly involved in painful shoulder conditions as a result of trauma, degeneration, or overuse. Recent studies have pointed out the close correlation between LHBT lesions and rotator cuff (RCT) tears. Clinicians need to take into account the importance of the LHBT in the presence of other shoulder pathologies. This paper provides an up-to-date overview of recent publications on anatomy, pathophysiology, diagnosis, classification, and current treatment strategies.

Ditsios, Konstantinos; Agathangelidis, Filon; Boutsiadis, Achilleas; Karataglis, Dimitrios; Papadopoulos, Pericles

2012-01-01

188

Scaffolds in Tendon Tissue Engineering  

PubMed Central

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.

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

2012-01-01

189

Tear Cholesterol Levels in Blepharitis  

Microsoft Academic Search

The tear levels of cholesterol of 17 patients with chronic blepharitis and 17 healthy subjects were determined by the photometric method. The mean cholesterol level of the patients was determined to be 56.1 ± 8.9 (SEM) mg\\/dl. No statistically significant difference between the tear cholesterol levels of the two groups could be detected.

A. O. Saatçi; N. Ünlü

1990-01-01

190

Meniscal Tear Film Fluid Dynamics Near Marx's Line.  

PubMed

Extensive studies have explored the dynamics of the ocular surface fluid, though theoretical investigations are typically limited to the use of the lubrication approximation, which is not guaranteed to be uniformly valid a-priori throughout the tear meniscus. However, resolving tear film behaviour within the meniscus and especially its apices is required to characterise the flow dynamics where the tear film is especially thin, and thus most susceptible to evaporatively induced hyperosmolarity and subsequent epithelial damage. Hence, we have explored the accuracy of the standard lubrication approximation for the tear film by explicit comparisons with the 2D Navier-Stokes model, considering both stationary and moving eyelids. Our results demonstrate that the lubrication model is qualitatively accurate except in the vicinity of the eyelids. In particular, and in contrast to lubrication theory, the solution of the full Navier-Stokes equations predict a distinct absence of fluid flow, and thus convective mixing in the region adjacent to the tear film contact line. These observations not only support emergent hypotheses concerning the formation of Marx's line, a region of epithelial cell staining adjacent to the contact line on the eyelid, but also enhance our understanding of the pathophysiological consequences of the flow profile near the tear film contact line. PMID:23820726

Zubkov, V S; Breward, C J W; Gaffney, E A

2013-07-03

191

High-intensity focused ultrasound ablation of ex vivo bovine achilles tendon.  

PubMed

Small tears in tendons are a common occurrence in athletes and others involved in strenuous physical activity. Natural healing in damaged tendons can result in disordered regrowth of the underlying collagen matrix of the tendon. These disordered regions are weaker than surrounding ordered regions of normal tendon and are prone to re-injury. Multiple cycles of injury and repair can lead to chronic tendinosis. Current treatment options either are invasive or are relatively ineffective in tendinosis without calcifications. High-intensity focused ultrasound (HIFU) has the potential to treat tendinosis noninvasively. HIFU ablation of tendons is based on a currently-used surgical analog, viz., needle tenotomy. This study tested the ability of HIFU beams to ablate bovine tendons ex vivo. Two ex vivo animal models were employed: a bare bovine Achilles tendon (deep digital flexor) on an acoustically absorbent rubber pad, and a layered model (chicken breast proximal, bovine Achilles tendon central and a glass plate distal to the transducer). The bare-tendon model enables examination of lesion formation under simple, ideal conditions; the layered model enables detection of possible damage to intervening soft tissue and consideration of the possibly confounding effects of distal bone. In both models, the tissues were degassed in normal phosphate-buffered saline. The bare tendon was brought to 23 degrees C or 37 degrees C before insonification; the layered model was brought to 37 degrees C before insonification. The annular array therapy transducer had an outer diameter of 33 mm, a focal length of 35 mm and a 14-mm diameter central hole to admit a confocal diagnostic transducer. The therapy transducer was excited with a continuous sinusoidal wave at 5.25 MHz to produce nominal in situ intensities from 0.23-2.6 kW/cm(2). Insonification times varied from 2-10 s. The focus was set over the range from the proximal tendon surface to 7 mm deep. The angle of incidence ranged from 0 degrees (normal to the tissue surface) to 15 degrees . After insonification, tendons were dissected and photographed, and the dimensions of the lesions were measured. Transmission electron micrographs were obtained from treated and untreated tissue regions. Insonification produced lesions that mimicked the shape of the focal region. When lesions were produced below the proximal tendon surface, no apparent damage to overlying soft tissue was apparent. The low intensities and short durations required for consistent lesion formation, and the relative insensitivity of ablation to small variations in the angle of incidence, highlight the potential of HIFU as a noninvasive treatment option for chronic tendinosis. PMID:18692293

Muratore, Robert; Akabas, Tal; Muratore, Isabella B

2008-08-09

192

Response of tibialis anterior tendon to a chronic exposure of stretch-shortening cycles: age effects  

PubMed Central

Background The purpose of the current study was to investigate the effects of aging on tendon response to repetitive exposures of stretch-shortening cycles (SSC's). Methods The left hind limb from young (3 mo, N = 4) and old (30 mo, N = 9) male Fisher 344 × Brown Norway rats were exposed to 80 maximal SSCs (60 deg/s, 50 deg range of motion) 3x/week for 4.5 weeks in vivo. After the last exposure, tendons from the tibialis anterior muscle were isolated, stored at -80°C, and then tested using a micro-mechanical testing machine. Deformation of each tendon was evaluated using both relative grip-to-grip displacements and reference marks via a video system. Results At failure, the young control tendons had higher strain magnitude than the young exposed (p < 0.01) and the old control tendons (p < .0001). Total load at inflection was affected by age only (p < 0.01). Old exposed and control tendons exhibited significantly higher loads at the inflection point than their young counterparts (p < 0.05 for both comparisons). At failure, the old exposed tendons carried higher loads than the young exposed tendons (p < 0.05). Stiffness was affected by age only at failure where the old tendons exhibited higher stiffness in both exposed and control tendons than their young counterparts (p < 0.05 and p < 0.01, respectively). Conclusion The chronic protocol enhanced the elastic stiffness of young tendon and the loads in both the young and old tendons. The old exposed tendons were found to exhibit higher load capacity than their younger counterparts, which differed from our initial hypothesis.

Ensey, James S; Hollander, Melinda S; Wu, John Z; Kashon, Michael L; Baker, Brent B; Cutlip, Robert G

2009-01-01

193

Linear stability of tearing modes  

SciTech Connect

This paper examines the stability of tearing modes in a sheared slab when the width of the tearing layer is much smaller than the ion Larmor radius. The ion response is nonlocal, and the quasineutrality retains its full integal form. An expansion procedure is introduced to solve the quasineutrality equation in powers of the width of the tearing layer over the ion Larmor radius. The expansion procedure is applied to the collisionless and semi-collisional tearing modes. The first order terms in the expansion we find to be strongly stabilizing. The physics of the mode and of the stabilization is discussed. Tearing modes are observed in experiments even though the slab theory predicts stability. It is proposed that these modes grow from an equilibrium with islands at the rational surfaces. If the equilibrium islands are wider than the ion Larmor radius, the mode is unstable when ..delta..' is positive.

Cowley, S.C.; Kulsrud, R.M.; Hahm, T.S.

1986-05-01

194

Tear-ducts in wine  

NASA Astrophysics Data System (ADS)

We examine the radial spoke pattern evident in the meniscus region in glasses of strong alcoholic beverages exhibiting the `tears-in-wine' phenomenon. We demonstrate that the pattern results from ridge-like elevations of the free surface which are supported by evaporatively-driven Marangoni convection in the meniscus region. Vortices associated with the convective motions are aligned in the radial direction by the surface tension gradient responsible for the generation of tears. The radial flow is focussed into the ridges, which thus serve as the principal conduits of fluid for the tears; consequently, we refer to the ridges as `tear-ducts'. The phenomenon is examined experimentally, and a numerical model of evaporatively-driven Marangoni convection is developed which reproduces the salient features of the tear-duct phenomenon.

Bush, John W. M.

1999-11-01

195

Tear proteomics in keratoconus  

PubMed Central

Purpose The purpose of this work was to identify potential tear-film based proteins expressed in keratoconus. Methods Recruited subjects were normal gas permeable (GP) contact lens wearers, keratoconus subjects wearing GP contact lenses, and keratoconus subjects without contact lenses. Subjects wearing soft lenses or having previous ocular surgeries were excluded from participating. Approximately 5 µl of tears were sampled from both eye of each subject using glass microcapillaries. Additional testing included a brief history, visual acuity, slit lamp examination, and topography. Proteomic analyses used to compare samples included Bradford assays, cytokine arrays, SDS–PAGE, and mass spectrometry. Results Forty-four subjects were enrolled in the study including 20 normals (GP wearers), 18 with keratoconus and wearing GPs, and six with keratoconus (non-lens wearers). Across all proteomic approaches, several proteins were identified as possibly being unique to keratoconus. Increased expression of matrix metalloproteinase-1 (MMP-1) was found in keratoconus subjects with and without gas permeable contact lenses (p=0.02). Unique proteins more associated with keratoconus included several keratins, immunoglobulins alpha and kappa, precursors to prolactin, lysozyme C, and lipocalin. Conclusions Initial analyses indicate that keratoconus may be associated with the differential expression of several proteins. Further testing is needed to determine any causal relationship or correlation with the etiology of this condition.

Pannebaker, Catherine; Chandler, Heather L.

2010-01-01

196

Tear secretion and tear film function in insulin dependent diabetics  

PubMed Central

BACKGROUND—Diabetic patients often complain of dry eye symptoms, such as burning and/or foreign body sensation. The aim of the present study was to investigate whether diabetes mellitus is correlated with tear film dysfunction and/or tear hyposecretion.?METHODS—In 86 consecutive insulin dependent diabetics with retinopathy and 84 non-diabetic controls (age and sex matched) we performed fluorophotometry of tear secretion, the Schirmer test, and impression cytology of the conjunctival epithelium and determined the tear film break up time.?RESULTS—When compared with the healthy control group diabetics showed decreased Schirmer test readings (?37%, p <0.001) and significantly more frequent and pronounced signs of conjunctival metaplasia. None of the other values differed between groups.?CONCLUSION—In insulin dependent diabetics, reflex tearing was demonstrated to be significantly decreased. In contrast, unstimulated basal tear flow and tear film break up time were found to be normal. However, a majority of insulin dependent diabetics shows distinct signs of conjunctival surface disease.??

Goebbels, M.

2000-01-01

197

Biomechanical comparison between single-bundle and double-bundle anterior cruciate ligament reconstruction with hamstring tendon under cyclic loading condition  

PubMed Central

Purpose The purpose of this study was to compare the anterior tibial translation (ATT) of the anterior cruciate ligament (ACL) reconstructed-knee between single-bundle and double-bundle ACL reconstruction under cyclic loading. Methods Single-bundle and double-bundle reconstructions of the knee were performed sequentially in randomized order on the same side using eight human amputated knees. After each reconstruction, the reconstructed-knee was subjected to 500-cycles of 0 to 100-N anterior tibial loads using a material testing machine. The ATT before and after cyclic loading and “laxity increase”, which indicated a permanent elongation of the graft construct, was also determined. Results The ATT after cyclic loading increased in both single-bundle and double-bundle reconstruction techniques compared to that without cyclic loading. Changes in ATT before and after cyclic loading were 3.9?±?0.9 mm and 2.9?±?0.6 mm respectively, and were significantly different. Laxity increase was also significantly different (4.3?±?0.9 mm and 3.2?±?0.8 mm respectively). Although no graft rupture or graft fixation failure was found during cyclic loading, the graft deviated into an eccentric position within the tunnel. Conclusions Although ATT was significantly increased in both single-bundle and double-bundle reconstruction with hamstring tendon after cyclic loading test, there was significant difference. Double-bundle reconstruction might be superior to prevent increasing ATT under cyclic loading. Deformation of hamstring tendon after cyclic loading might result in deterioration of knee stability after ACL reconstruction, and is one of disadvantages of soft tissue graft.

2012-01-01

198

Suture-bridge subscapularis tendon repair technique using low anterior portals.  

PubMed

A suture-bridge technique has been introduced to facilitate fixation procedures and to achieve increased holding strength in posterosuperior rotator cuff. Based on biomechanical studies, this technique has been suggested as an effective method that could optimize rotator cuff tendon-footprint contact area and mean pressure, as well as holding strength. In this technique, the suture-bridge creation is adapted for arthroscopic subscapularis repair to attain the ideal cuff integrity and footprint restoration. To obtain enough working portals and space, two accessory portals were made on the anterior aspect of the shoulder and use an elevator to retract the conjoined tendons and deltoid muscle. This technique could be useful for the repair of subscapularis tears, which are not easily approached using other arthroscopic techniques. From a biomechanical point of view, the subscapularis tendon could be restored more ideally using the suture-bridge technique. PMID:20890701

Park, Jin-Young; Park, Jun-Suk; Jung, Jae-Kyung; Kumar, Praveen; Oh, Kyung-Soo

2010-10-02

199

Correlation of acromial morphology with impingement syndrome and rotator cuff tears  

PubMed Central

Background and purpose Indications for acromioplasty are based on clinical symptoms and are generally supported by typical changes in acromial morphology on standard radiographs. We evaluated 5 commonly used radiographic parameters of acromial morphology and assessed the association between different radiographic characteristics on the one hand and subacromial impingement or rotator cuff tears on the other. Patients and methods We measured acromial type (Bigliani), acromial slope (AS), acromial tilt (AT), lateral acromial angle (LAA), and acromion index (AI) on standard radiographs from 50 patients with full-thickness supraspinatus tendon tears, 50 patients with subacromial impingement, and 50 controls without subacromial pathology. Results The acromial type according to Bigliani was not associated with any particular cuff lesion. A statistically significant difference between controls and impingement patients was found for AS. AT of controls was significantly smaller than that of impingement patients and cuff-tear patients. LAA of cuff-tear patients differed significantly from that of controls and impingement patients, but LAA of controls was not significantly different from that of impingement patients. Differences between impingement patients and cuff-tear patients were also significant. AI of controls was significantly lower than of impingement patients and of cuff-tear patients. A good correlation was found between acromial type and AS. Interpretation A low lateral acromial angle and a large lateral extension of the acromion were associated with a higher prevalence of impingement and rotator cuff tears. An extremely hooked anterior acromion with a slope of more than 43° and an LAA of less than 70° only occurred in patients with rotator cuff tears.

2013-01-01

200

Tear lipocalin: structure and function.  

PubMed

Lipocalins are a family of diverse low molecular weight proteins that act extracellularly. They use multiple recognition properties that include 1) ligand binding to small hydrophobic molecules, 2) macromolecular complexation with other soluble macromolecules, and 3) binding to specific cell surface receptors to deliver cargo. Tear lipocalin (TLC) is a major protein in tears and has a large ligand-binding cavity that allows the lipocalin to bind an extensive and diverse set of lipophilic molecules. TLC can also bind to macromolecules, including the tear proteins lactoferin and lysozyme. The receptor to which TLC binds is termed tear lipocalin-interacting membrane receptor (LIMR). LIMR appears to work by endocytosis. TLC has a variety of suggested functions in tears, including regulation of tear viscosity, binding and release of lipids, endonuclease inactivation of viral DNA, binding of microbial siderophores (iron chelators used to deliver essential iron to bacteria), serving as a biomarker for dry eye, and possessing anti-inflammatory activity. Additional research is warranted to determine the actual functions of TLC in tears and the presence of its receptor on the ocular surface. PMID:21791187

Dartt, Darlene A

2011-07-01

201

The subaortic tendon as a mimic of hypertrophic cardiomyopathy.  

PubMed

Originally described by Brock and Teare, today hypertrophic cardiomyopathy is clinically defined as left (or right) ventricular hypertrophy without a known cardiac or systemic cause, such as systemic hypertension, Fabry's disease or aortic stenosis.Also appreciated today is the enormous genotypic and phenotypic heterogeneity of this disease with more than 300 mutations over more than 24 genes, encoding various sarcomeric, mitochondrial and calcium-handling proteins, all as genetic causes for hypertrophic cardiomyopathy.Phenotypically, the disease can vary from negligible to extreme hypertrophy, affecting either the left and/or right ventricle in an apical, midventricular or subaortic location.Left ventricular false tendons are thin, fibrous or fibromuscular structures that traverse the left ventricular cavity. Recently, a case report was presented where it was shown that such a false tendon, originating from a subaortic location, was responsible for striking ST-segment elevation on the surface electrocardiogram.In this case report, a case is presented where such a subaortic tendon led to the classic echocardiographic appearance of hypertrophic cardiomyopathy, thus in the assessment of hypertrophic cardiomyopathy, this entity needs to be excluded in order to prevent a false positive diagnosis of hypertrophic cardiomyopathy. PMID:19573250

Ker, James

2009-07-03

202

Temporary tendon strengthening by preconditioning  

Microsoft Academic Search

BackgroundTendon is frequently injured structure in sports activities. Stretching before activities has been recommended to prevent athletes from injuries. Clinical studies reported that stretching had effects to reduce passive muscle stiffness and leads to an increased range of motion. Recent biomechanical studies suggested that stretching might also temporary affect tensile property of tendon. However, the detailed information regarding optimizing this

Atsushi Teramoto; Zong-Ping Luo

2008-01-01

203

ACL reconstruction by patellar tendon  

Microsoft Academic Search

In 50 knees the length of the anterior cruciate ligament (ACL), the patellar tendon, and the distance between the tibial tuberosity and the femoral origin of the ACL were evaluated by means of three-dimensional magnetic resonance imaging (MRI), which permits subsequent reconstruction of any sectional view. The measurements showed that the patellar tendon was always markedly longer than the ACL

S. Högerle; R. Letsch; K. W. Sievers

1998-01-01

204

Fatigue damage of human tendons  

Microsoft Academic Search

The study was designed to examine the effects of partial fatigue on specific mechanical parameters which characterise human tendons in vitro. Specimens prepared from 12 intact Extensor digitorum longus tendons of the foot were subjected to partial fatigue, equivalent to 25% of the median fatigue life, by a cyclic square tension–tension stress waveform at the physiological frequency of 4Hz. The

H. Schechtman; D. L. Bader

2002-01-01

205

Creep rupture of wallaby tail tendons.  

PubMed

The tail tendons from wallabies (Macropus rufogriseus) suffer creep rupture at stresses of 10 MPa or above, whereas their yield stress in a dynamic test is about 144 MPa. At stresses between 20 and 80 MPa, the time-to-rupture decreases exponentially with stress, but at 10 MPa, the lifetime is well above this exponential. For comparison, the stress on a wallaby tail tendon, when its muscle contracts isometrically, is about 13.5 MPa. Creep lifetime depends sharply on temperature and on specimen length, in contrast to strength and stiffness as observed in dynamic tests. The creep curve (strain versus time) can be considered as a combination of primary creep (decelerating strain) and tertiary creep (accelerating strain). Primary creep is non-damaging, but tertiary creep is accompanied by accumulating damage, with loss of stiffness and strength. 'Damage' is quantitatively defined as the fractional loss of stiffness. A creep theory is developed in which the whole of tertiary creep and, in particular, the creep lifetime are predicted from measurements made at the onset of creep, when the tendon is undamaged. This theory is based on a 'damage hypothesis', which can be stated as: damaged material no longer contributes to stiffness and strength, whereas intact material makes its full contribution to both. PMID:9244804

Wang, X T; Ker, R F

1995-03-01

206

Achilles tendon rehabilitation.  

PubMed

The operative management of acute Achilles tendon rupture marks the beginning of a comprehensive rehabilitation program. The goals of the rehabilitation program start with the reduction of pain and swelling and the recovery of ankle motion and power. They conclude with the restoration of coordinated activity and safe return to athletic activity. The rehabilitation protocol is directed by the injury and the quality of the repair, along with the patient's age, medical and social history, and athletic inclination. The protocol is dynamic and responsive to changing clinical findings. PMID:19857848

Strom, Adam C; Casillas, Mark M

2009-12-01

207

Greater tuberosity notch: an important indicator of articular-side partial rotator cuff tears in the shoulders of throwing athletes.  

PubMed

We examined the location of rotator cuff tears, associated labral injuries, and notches on the greater tuberosity of the humeral head in shoulders of throwing athletes. Arthroscopic findings (rotator cuff tear, labral condition, and greater tuberosity notch) as well as other factors (duration of playing baseball, range of motion, and joint laxity) of 61 baseball players were retrospectively studied. The presence of a greater tuberosity notch was also evaluated for by plain radiographs. Forty patients had articular-side partial rotator cuff tears, most of which occurred in the interval between the supraspinatus and infraspinatus tendons. The existence of a rotator cuff tear was not related to the range of motion, joint laxity, the detachment of the superior glenoid labrum, or posterosuperior labral injury. Greater tuberosity notches were recognized in 38 shoulders by arthroscopy and most were detected on plain radiographs. The presence of a notch was significantly related to the existence of a rotator cuff tear, while the size of the notch was significantly related to the depth and width of the tear. The greater tuberosity notch seems to be one of the most important diagnostic indicators for a rotator cuff tear in throwing athletes. PMID:11734490

Nakagawa, S; Yoneda, M; Hayashida, K; Wakitani, S; Okamura, K

208

Tearing-mode instability in cylindrical plasma configurations  

Microsoft Academic Search

The effect of cylindrical neutral sheet geometry on the tearing-mode (disruptive) instability is studied in detail. The instability growth rates are found for all the pertinent cases. Cylindrical effects come into play when the distance from the neutral sheet to the axis is small in comparison with the characteristic thickness of the sheet. The ultimate result is that the electron

L. M. Zelenyi

1979-01-01

209

Lactoferrin levels in normal human tears  

Microsoft Academic Search

Using commercially available reagents we developed an enzyme-linked immunosorbent assay to measure lactoferrin in normal human tears. Tears obtained from 38 normal human subjects contained a mean lactoferrin content of 2.2 mg\\/ml (g\\/l). No differences in the mean level of lactoferrin were found when tears were collected by either Schirmer tear strips or by glass capillaries after short tear gas

A Kijlstra; S H Jeurissen; K M Koning

1983-01-01

210

Long term results of surgical intervention for osteoarthritis of the trapeziometacarpal joint : comparison of resection arthroplasty, trapeziectomy with tendon interposition and trapezio-metacarpal arthrodesis.  

PubMed

Trapeziometacarpal osteoarthritis is a common entity, often bilateral and predominantly affecting postmenopausal women. In the case of failure of conservative treatment, surgery is a good option. The aim of this study was to compare three surgical procedures. 63 patients (74 thumbs) with osteoarthritis of the trapezio-metacarpal joint were surgically treated; 54 patients were seen for follow-up, 7 had died and 2 were lost to follow-up. The patients were stratified according to treatment; resection arthroplasty (the joint surface's of the metacarpal and the trapezium are resected) (18 thumbs), trapeziectomy with tendon interposition (17 thumbs) or trapezio-metacarpal arthrodesis (28 thumbs). Baseline characteristics were comparable in the three groups for mean age at operation, Eaton classification, left right distribution and dominant hands operated. The average follow-up was 13 years for the resection group, 8 years for the trapeziectomy group and 9 years for the arthrodesis group. No statistically significant difference between the three groups was found for the visual analogue pain and satisfaction scale, pain frequency nor DASH score. Patients in the trapeziectomy group had significantly less pain compared to the arthrodesis group (p=0.025). Statistically, radial abduction was significantly better after trapeziectomy compared to resection arthroplasty (p<0.01) or arthrodesis (p=0.01). There was no difference among the three groups in grip and tip pinch strength nor in pain on palpation. None of the patients in the trapeziectomy group needed a re-operation, one patient in the resection arthroplasty group had a re-operation, and 22 patients in the arthrodesis group had one or more re-operations for hardware removal or because of a complication. This study shows that the resection arthroplasty has equally good long term results compared to trapeziectomy combined with tendon interposition or arthrodesis. Resection arthroplasty is performed through a single incision and is technically simple. In our clinic resection arthroplasty is therefore the preferred technique for the treatment of osteoarthritis of the trapeziometacarpal joint. PMID:17021835

Raven, E E J; Kerkhoffs, G M M J; Rutten, S; Marsman, A J W; Marti, R K; Albers, G H R

2006-09-22

211

Deposition of collagenous matrices by tendon fibroblasts in vitro: a comparison of fibroblast behavior in pellet cultures and a novel three-dimensional long-term scaffoldless culture system.  

PubMed

Tendons transmit tensile loads from muscle to bone. They consist primarily of parallel collagen fibers between longitudinally oriented rows of tendon fibroblasts. In this study, we describe a novel scaffoldless dialysis-roller culture system that allows tendon cells to form large, organized, tendon-like structures. We compare cell and collagen orientation and synthesis in these cultures with that of monolayer and high-density pellet cultures. Monolayers are unable to deposit a substantial matrix, losing most of their secreted collagen to the medium. High-density pellet cultures deposit more matrix, lose less to the medium, and become organized at their periphery but show signs of nutritional compromise in the center core. In the novel system, cells formed highly organized structures resembling embryonic tendons, synthesized much more collagen, and incorporated around 70% of the secreted collagen into the tendon-like extracellular matrix. The three-dimensional cultures appear to allow substantial cell-cell interactions and may mimic important aspects of the early development of tendons, including the formation of membrane-bound extracellular spaces to contain and organize the secreted collagen. PMID:19366312

de Wreede, Rhiannon; Ralphs, James R

2009-09-01

212

Congenital Aberrant Tearing: A Re-Look  

PubMed Central

Purpose Congenital aberrant tearing is characterized by tearing when eating (“crocodile tears”), lack of emotional tearing, or both. Most reported cases are associated with Duane syndrome. In our previous studies we observed aberrant tearing in individuals with thalidomide embryopathy and Möbius sequence. This report summarizes the literature on the subject and adds 3 new studies that give information on this unusual condition. Methods Twenty-eight individuals with Möbius sequence were interviewed about tearing symptoms at a support group meeting in Italy. In Sweden 30 adults primarily from the original thalidomide series were reexamined. In this latter study, a Schirmer test was done at baseline and repeated 5 minutes after eating. Twenty families in Brazil who have children with Möbius sequence were questioned about tearing symptoms and exposure to misoprostol during pregnancy. Results In the 28 Italian individuals, either “crocodile tears” or lack of emotional tearing was noted in 7 cases. In the thalidomide study, 10 of 30 patients had tearing when eating and 7 had no emotional tearing. Low Schirmer scores or increased tearing after eating was noted in a few asymptomatic individuals. Among the 20 Brazilian children with Möbius sequence, 10 had some tearing abnormality. Conclusion Congenital anomalous lacrimation is rare but usually associated with Duane syndrome or abduction deficits, as in Möbius sequence and, less frequently, facial nerve palsy. Studies implicate an early insult in development at 4 to 6 weeks. At that time the facial nerve, sixth nerve, and lacrimal nucleus are in close proximity in the embryo.

Miller, Marilyn T.; Stromland, Kerstin; Ventura, Liana

2008-01-01

213

Human basic tear fluid osmolality. I. Importance of sample collection strategy.  

PubMed

Osmolalities of 200 human tear prism fluid samples collected from two subjects were determined from their melting-point temperatures with the Clifton Nanoliter Osmometer by calibration with 200 standard solution samples (290 mOsm/kg). Comparisons were made between tear fluid osmolalities obtained using a single-sample simultaneous-recalibration method: 1) for tear samples collected using finely-drawn microcapillaries without biomicroscopy, vs secondly with biomicroscopic observation by illumination of only the sampling area on the inferior tear prism, the two collections separated by an interval of 10 min; and 2) for samples collected without biomicroscopy before, vs after a 10-min interval. Tear fluid collection using a biomicroscope resulted in values that were significantly lower than those collected without (overall mean = 299.5 and 306.6 mOsm/kg, respectively; p < 0.0001). The difference (7.1 mOsm/kg) may have resulted from mechanical, photic, and/or psychogenic reflex stimulation due to biomicroscopy, as the 10-min interval had no osmotic effect on samples collected without biomicroscopy. Based on these results from two subjects, we suggest that relatively rapid, repetitive collections of human tear prism fluid can be made without significantly disturbing the osmotic outcome. However, physiological representation of basic human tear fluid is more accurate by avoidance of reflex-inducing collection methods that were formerly considered unobtrusive. Basic human tear prism fluid is more hypertonic, by at least 7 mOsm/kg, than generally realized. PMID:8249586

White, K M; Benjamin, W J; Hill, R M

1993-08-01

214

Multiple tendon ruptures of unknown etiology.  

PubMed

Tendon ruptures are common findings in foot and ankle practice. The etiology of tendon ruptures tends to be multifactorial-usually due to a combination of trauma, effects of systemic diseases, adverse effects of medications, and obesity. We present an unusual case of right Achilles tendinitis, left Achilles tendon rupture, bilateral peroneus longus tendon rupture, and left peroneus brevis tendon rupture of unknown etiology. This case report highlights the need for research for other possible, lesser known etiologies of tendon pathology. Level of Evidence: Therapeutic, Level IV, Case Study. PMID:23966259

Axibal, Derek P; Anderson, John G

2013-08-21

215

Quantitative tear ferning. Clinical investigations.  

PubMed

The tears of 225 subjects were examined for several disorders of the eye by means of a newly developed method, the quantitative tear ferning test. Of the 225 subjects, 89 were normal controls, 24 were examined before and after cataract extraction, and 112 had some disease of the external part of the eye. Using the quantitative tear ferning test, it was shown that compared to normals, the ferning area was significantly decreased in cases of keratoconjunctivitis sicca, in primary and in secondary Sjögren's syndrome. This was also the case in infectious conjunctivitis and after cataract extraction, possibly due to exudation from the conjunctival vessels. In simple conjunctivitis, however, the ferning area was normal. The ferning method has a sensitivity and a specificity of the same order as the commonly used tests for Sjögren's syndrome (Schirmer I, BUT, rose bengale, lactoferrin). PMID:7976270

Norn, M

1994-06-01

216

Radial side (1D) tears.  

PubMed

The triangular fibrocartilage complex (TFCC) is the key structure at the wrist that facilitates the rotation of the radius and the carpus on the distal ulnar. The radial or type 1D tears of the TFCC are uncommon, but they pose a major disruption of the articular contact between the carpus and the distal ulna. The tears can heal by arthroscopically repairing the TFCC back to the radius using sutures through bone tunnels. This procedure allows patients to return to their work and sports activities with significant recovery of strength and range of motion. PMID:21871347

Trumble, Thomas

2011-08-01

217

Bilateral patellar tendon ruptures without predisposing systemic disease or steroid use: a case report and review of the literature.  

PubMed

Simultaneous bilateral patellar tendon rupture occurs rarely and is even rarer in patients without systemic disease or predisposing conditions. We present a case of bilateral, midsubstance patellar tendon ruptures along with a partial anterior cruciate ligament tear from a fall from a standing height in an otherwise healthy adult without any predisposing conditions. Most patients that sustain a tendon rupture have risk factors for tendonopathy including chronic renal disease, systemic lupus erythematosus, rheumatoid arthritis, or exposure to medications (such as corticosteroids or fluoroquinolones). Currently, there are approximately 50 reported cases of bilateral patellar tendon rupture in the scientific literature; however, only a small minority occurred in patients without any predisposing factors. Most of the reports of a bilateral tendon rupture without systemic disease occurred in the inferior pole of the tendon, with only a few of these occurring in the midsubstance. Because of the rarity of this event in a patient without systemic disease, this condition is often misdiagnosed. Emergency physicians should maintain a high degree of suspicion in those patients with concerning clinical and/or radiographic findings. PMID:21185665

Sibley, Ted; Algren, D Adam; Ellison, Stefanie

2010-12-24

218

Finite Element Model of Subsynovial Connective Tissue Deformation due to Tendon Excursion in the Human Carpal Tunnel  

PubMed Central

Carpal Tunnel Syndrome (CTS) is a nerve entrapment disease which has been extensively studied by the engineering and medical community. Although the direct cause is unknown, in vivo and in vitro medical research has shown that tendon excursion creates micro tears in the subsynovial connective tissue (SSCT) surrounding the tendon in the carpal tunnel. One proposed mechanism for the SSCT injury is shearing which is believed to cause fibrosis of the SSCT. Few studies have reported quantitative observations of SSCT response to mechanical loading. Our proposed model is a 2-D section that consists of an FDS tendon, interstitial SSCT and adjacent stationary tendons. We believe that developing this model will allow the most complete quantitative observations of SSCT response to mechanical loading reported thus far. Boundary conditions were applied to the FEA model to simulate single finger flexion. A velocity was applied to the FDS tendon in the model to match loading conditions of the documented cadaver wrist kinematics studies. The cadaveric and FEA displacement results were compared to investigate the magnitude of stiffness required for the SSCT section of the model. The relative motions between the model and cadavers matched more closely than the absolute displacements. Since cadaveric models do not allow identification of the SSCT layers, an FEA model will help determine the displacement and stress experienced by each SSCT layer. Thus, we believe this conceptual model is a first step in understanding how the SSCT layers are recruited during tendon excursion.

Henderson, Jacqueline; Thoreson, Andrew; Yoshii, Yuichi; Zhao, Kristin D.; Amadio, Peter C.; An, Kai-Nan

2010-01-01

219

Hall resistive tearing mode: A variational formulation  

Microsoft Academic Search

A unified linear tearing-mode formulation is given incorporating both resistivity and Hall effects. A variational method is used that appears to be best suited to deal with the difficulties peculiar to the triple-deck structure associated with the Hall resistive tearing mode but also to lead to a convenient analytical dispersion relation for the Hall resisitive tearing mode. This analytical dispersion

B. K. Shivamoggi

2008-01-01

220

Locked bucket handle tears of the medial and lateral menisci with associated chronic ACL deficiency.  

PubMed

Bucket handle meniscal tears involving both the medial and lateral menisci are very rarely reported in the literature. Those that are, have generally been managed using a one-stage procedure, with concurrent reconstruction of the anterior cruciate ligament (ACL) in ACL-deficient cases. We report a case of an 18-year old male who presented with bi-compartmental bucket handle meniscal tears with an associated ACL deficiency, whereby the medial and lateral tears appear to have clearly occurred on separate occasions. A staged approach to management was adopted. We discuss the presentation and management of our case in comparison to previously reported cases. PMID:23402074

Shepherd, J; Abdul-Jabar, H B; Kumar, A

2012-12-01

221

A Overset Grid Method for Fourth Order Evolution Equations of Human Tear Film  

NASA Astrophysics Data System (ADS)

We developed an overset grid method to simulate the formation and relaxation of the human tear film over multiple blink cycles. We studied limiting cases of the absence and presence of insoluble surfactants on the film's free surface. The evolution is described by a single fourth order nonlinear partial differential equation that arises from lubrication theory on a domain whose length varies significantly with time. Numerical computations, found by implementing a finite difference based method of lines on a overset grid, explore the dynamics of the tear film including the effects of evaporation, gravity, intermolecular forces and reflex tearing. Comparison with in vivo measurements are made.

Maki, K. L.; Braun, R. J.; Driscoll, T. A.; Heryudono, A.; King-Smith, P. E.; Fast, P.

2007-11-01

222

Assessment of the long head of the biceps tendon of the shoulder with 3T magnetic resonance arthrography and CT arthrography.  

PubMed

We studied the assessment of proximal biceps tendon lesions including degeneration, tendon luxation, and partial and complete tendon tears with 3T MR arthrography and CT arthrography. Thirty-six patients who underwent both studies, as well as arthroscopy were included in the study. The images were randomized and blinded and independently reviewed by two musculoskeletal radiologists. The pooled sensitivity for lesion detection for CT arthrography was 31% and the specificity 95%. The pooled sensitivity for MR arthrography was 27% and the specificity 94%. There were no statistically significant differences between CT and MR. The interobserver agreement calculated with the kappa statistic was poor for CT and for MR. Both CT arthrography and MR arthrography perform poorly in the detection of biceps tendon pathology of the shoulder. PMID:21367551

De Maeseneer, Michel; Boulet, Cedric; Pouliart, Nicole; Kichouh, Mimoun; Buls, Nico; Verhelle, Filip; De Mey, Johan; Shahabpour, Maryam

2011-03-01

223

Footprint reconstruction in a rotator cuff tear associated cyst of the greater tuberosity: augmented anchorage.  

PubMed

Tears of the rotator cuff (RC) complicated by bone cysts at the footprint might represent a challenge for the shoulder surgeon. This might be additionally aggravated in elderly patients with inferior bone quality due to osteopenia or osteoporosis. In this report we present a technique for open repair of RC tears by augmenting the cystic lesion at the greater tuberosity using bone void filler in combination with a double row anchor reconstruction technique. Despite disadvantageous position and size of the cyst, using this technique the footprint can be restored by obtaining an anatomical position of the supraspinatus tendon. The application range of this technique is not limited to defined bony defects and presents a promising novel surgical approach. Level of evidence V. PMID:23070221

Postl, L K; Braunstein, V; von Eisenhart-Rothe, R; Kirchhoff, C

2012-10-16

224

[Fixed posterior sag position after ACL reconstruction for an apparently "isolated" ACL tear].  

PubMed

We present the case of a paraglider who suffered a valgus external rotation hyperextension injury of the right knee. The incomplete diagnosis of an isolated anterior cruciate ligament (ACL) intrasubstance tear was made and a reconstruction of the ACL with semitendinosus autograft was performed. The associated lesion of the posterior cruciate ligament (PCL) was overlooked and thus the ACL was fixed in a posterior sag position. This led to activity-related pain without any instability. The patient underwent revision surgery with débridement of the ACL and reconstruction of the PCL with quadriceps tendon. PMID:19517092

Hirschmann, M T; El Rabadi, J; Mueller, C; Friederich, N F

2009-07-01

225

Open repair of acute Achilles tendon ruptures.  

PubMed

Although the Achilles tendon is the strongest in the body, it also is the most often ruptured. Achilles tendon rupture most often occurs during sports activities in middle-aged men. Operative repair of a ruptured Achilles tendon can be accomplished with a variety of techniques, ranging from open repair, to minimally invasive technique, to endoscopic-assisted repair. This article focuses on open repair of acute Achilles tendon rupture. Surgical techniques, rehabilitation protocol, and the authors' preferred method are described. PMID:19857843

Rosenzweig, Seth; Azar, Frederick M

2009-12-01

226

Silastic tendon graft: its role in neglected tendon repair.  

PubMed

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

LaBarbiera, A P; Solitto, R J

227

Observation of nonlinear neoclassical {sub p}-driven tearing modes in TFTR  

Microsoft Academic Search

A quantitative comparison is made between the tearing-type modes observed supershot plasmas and the nonlinear, neoclassical pressure gradient ({sub p}) driven tearing mode theory. Good agreement is found on the nonlinear magnetic island evolution of a single helicity mode (m\\/n = 3\\/2, 4\\/3 or 5\\/4, where m and n are the poloidal and toroidal mode numbers, respectively). Statistical data on

Z. Chang; J. D. Callen; C. C. Hegna; E. D. Fredrickson; R. V. Budny; K. M. McGuire; M. C. Zarnstorff

1994-01-01

228

Human basic tear fluid osmolality. II. Importance of processing strategy.  

PubMed

Osmolalities of 100 human inferior tear prism fluid samples collected from two subjects and 100 standard solution samples (290 mOsm/Kg) were determined from their melting-point temperatures with the Clifton Nanoliter Osmometer. Accuracy and reliability comparisons were made for endpoints obtained using a single-sample simultaneous-recalibration (SS/SR) strategy, vs a lowest-of-six periodic-recalibration (LS/PR) strategy. Tear fluid osmolality values based on the LS/PR strategy were significantly lower (hypotonic) than for the SS/SR strategy (overall mean = 302.4 and 307.8 mOsm/Kg, respectively; p < 0.0012). The mean difference (5.4 mOsm/Kg) resulted from the combined effects of machine drift and reduced reliability of endpoint determination for tear fluid in comparison to that of a homogenous standard solution. LS/PR osmolality was linearly correlated to SS/SR osmolality with a slope of 0.433 and the two endpoint strategies resulted in equivalent values at 298.4 mOsm/Kg. Eighty-four percent (84%) of individual osmolality readings were greater than 298.4 mOsm/kg, and an 'averaging-type' effect caused LS/PR osmolalities to be increasingly less than SS/SR values above this value. These outcomes from two subjects were approximated by a parallel statistical model. We suggest that physiological representation of basic human tear fluid is more accurate using the single-sample simultaneous-recalibration strategy. Basic human tear prism fluid is more hypertonic and has a greater within-subject range in normal (non-dry eye) humans than previously realized. PMID:8249587

White, K M; Benjamin, W J; Hill, R M

1993-08-01

229

Current evidence for effectiveness of interventions to treat rotator cuff tears.  

PubMed

In this systematic review we assessed effectiveness of non-surgical and (post)surgical interventions for symptomatic rotator cuff tears (RotCuffTear). The Cochrane Library, PubMed, Embase, Cinahl, and Pedro were searched for relevant systematic reviews and randomized controlled trials (RCTs). Two reviewers independently selected relevant studies, extracted data and assessed the methodological quality. Three Cochrane reviews (7 RCTs) and 14 RCTs were included (3 non-surgery, 10 surgery, 8 post-surgery). For small or medium RotCufftears, moderate evidence was found in favour of surgery versus physiotherapy in mid- and long-term. In surgery, tendon-to-bone fixation with one metal suture anchor loaded with double sutures (TB) was more effective (moderate evidence) than a side-to-side repair with permanent sutures (SS) in the mid- and long-term; limited evidence for effectiveness was found in favour of debridement versus anchor replacement and suture repair of the type II SLAP tear in the long-term. Further, no evidence was found in favour of any non-surgical, surgical or post-surgical intervention. In conclusion, although surgery seems to give better results compared to non-surgery and TB is more effective than SS in rotator cuff repair (RCR), it remains hard to draw firm evidence-based conclusions for effectiveness of non-surgical or (post)surgical interventions to treat RotCuffTears. More research is clearly needed. PMID:21146445

Huisstede, Bionka M A; Koes, Bart W; Gebremariam, Lukas; Keijsers, Ellen; Verhaar, Jan A N

2010-12-10

230

Ultrasound Evaluation of Flexor Tendon Lacerations  

Microsoft Academic Search

Thirteen injured digits in 10 patients (10 hands) with 20 potentially injured flexor tendons were preoperatively evaluated using real-time ultrasonography. The time interval between injury and ultrasonographic evaluation averaged 22 days. If a complete tendon laceration was found, the location of the proximal tendon stump was determined. Surgery was performed an average of 4 days after the ultrasonographic evaluation to

Donald H. Lee; Michelle L. Robbin; Robert Galliott; Veronica A. Graveman

2000-01-01

231

Staged tendon grafts and soft tissue coverage  

PubMed Central

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.

Elliot, David

2011-01-01

232

Triceps tendon rupture in weight lifters  

Microsoft Academic Search

Triceps tendon avulsion injuries are rare. We report four weight lifters with triceps tendon raptures, two of whom had received local steroid injections for pain in the triceps. All four patients had taken oral anabolic steroids before injury. All patients had closed avulsion of the triceps tendon from its insertion into the olecranon. Three patients were injured while bench pressing

Jonathan L Sollender; Ghazi M Rayan; Glen A Barden

1998-01-01

233

Finger Exoskeleton for Treatment of Tendon Injuries  

Microsoft Academic Search

A finger exoskeleton has been developed to aid treatment of tendon injuries. The exoskeleton is designed to assist flexion\\/extension motions of a finger within its full range, in a natural and coordinated manner, \\u000awhile keeping the tendon tension within acceptable limits to avoid gap formation or rupture of the suture. In addition to offering robot assisted operation modes for tendon

Ismail Hakan Ertas; Elif Hocaoglu; Duygun Erol Barkana; Volkan Patoglu

2009-01-01

234

MRI of tibialis anterior tendon rupture  

Microsoft Academic Search

Ruptures of the tibialis anterior tendon are rare. We present the clinical histories and MRI findings of three recent male patients with tibialis anterior tendon rupture aged 58–67 years, all of whom presented with pain over the dorsum of the ankle. Two of the three patients presented with complete rupture showing discontinuity of the tendon, thickening of the retracted portion of

Robert A. Gallo; Brett H. Kolman; Richard H. Daffner; Robert L. Sciulli; Catherine C. Roberts; Patrick J. DeMeo

2004-01-01

235

Hot tearing studies in AA5182  

NASA Astrophysics Data System (ADS)

One of the major problems during direct chill (DC) casting is hot tearing. These tears initiate during solidification of the alloy and may run through the entire ingot. To study the hot tearing mechanism, tensile tests were carried out in semisolid state and at low strain rates, and crack propagation was studied in situ by scanning electron microscopy (SEM). These experimentally induced cracks were compared with hot tears developed in an AA5182 ingot during a casting trial in an industrial research facility. Similarities in the microstructure of the tensile test specimens and the hot tears indicate that hot tearing can be simulated by performing tensile tests at semisolid temperatures. The experimental data were compared with existing hot tearing models and it was concluded that the latter are restricted to relatively high liquid fractions because they do not take into account the existence of solid bridges in the crack.

van Haaften, W. M.; Kool, W. H.; Katgerman, L.

2002-10-01

236

Achilles tendon reflex measuring system  

NASA Astrophysics Data System (ADS)

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.

Szebeszczyk, Janina; Straszecka, Joanna

1995-06-01

237

Secondary tearing mode in the nonlinear evolution of magnetorotational instability  

Microsoft Academic Search

Numerical investigation of the two-dimensional magnetic reconnection is given in the context of the nonlinear evolution of the Magneto-Rotational Instability (MRI). With a careful comparison to various theories using both one- and two-dimensional analysis, it is found that a new stabilizing effect of the centrifugal force on tearing instability must be present in the specific geometry of the MRI. Magnetic

T. Tatsuno; W. Dorland

2008-01-01

238

REHABILITATION OF A PARTIALLY TORN DISTAL TRICEPS TENDON AFTER PLATELET RICH PLASMA INJECTION: A CASE REPORT  

PubMed Central

Background: Platelet Rich Plasma (PRP) is an emerging non?surgical intervention used for the treatment of tendon and ligament pathology. Despite the growing popularity of PRP in musculoskeletal medicine, there is a paucity of research that describes appropriate rehabilitation procedures following this intervention. Case Description: This case report presents the rehabilitation strategy used following a PRP injection for a patient with a partially torn distal triceps tendon who previously failed physical therapy interventions. Outcome: The patient returned to light weight training and coaching activity after completing 15 visits over a 3 month period. One month after discharge, the patient reported pain?free activities of daily living and a return to previously performed gym activities. Discussion: PRP presents a viable treatment option for individuals who are recalcitrant to conservative interventions yet elect to avoid more invasive surgical measures. Despite the growing popularity of PRP, a paucity of evidence exists to guide physical therapists in the rehabilitation process of these patients. The rehabilitation strategies used in a patient who had a PRP injection for a partial triceps tendon tear are outlined. Although this case report highlights a successful rehabilitation outcome, future research regarding the concomitant effects of PRP injection and rehabilitation for tendon pathology are needed. Level of Evidence: 4?Case Report

Kolber, Morey J.; Salamh, Paul A.; Hanney, William J.

2013-01-01

239

Wild-type transthyretin-derived amyloidosis in various ligaments and tendons.  

PubMed

Transthyretin-derived amyloid deposition is commonly found in intercarpal ligaments of patients with senile systemic amyloidosis. However, the frequency of transthyretin-derived amyloid deposits in ligaments of other tissues remains to be elucidated. This study aimed to determine the frequency of amyloid deposition and the precursor proteins of amyloid found in orthopedic disorders. We studied 111 specimens from patients with carpal tunnel syndrome (flexor tenosynovium specimens), rotator cuff tears (rotator cuff tendon specimens), and lumbar canal stenosis (yellow ligament specimens). To identify amyloid precursor proteins, we used immunohistochemical staining with antibodies that react with transthyretin, immunoglobulin light chain, amyloid A protein, and ?(2)-microglobulin. By means of Congo red staining, we identified 47 (42.3%) amyloid-positive samples, 39 of which contained transthyretin-derived amyloid (18 flexor tenosynovium specimens, 5 rotator cuff tendon specimens, and 16 yellow ligament specimens). Genetic testing and/or clinical findings suggested that all patients with transthyretin amyloid deposits did not have familial amyloidotic polyneuropathy. The occurrence of amyloid deposition in those tissues depended on age. These results suggest that transthyretin-derived amyloid deposits may occur more frequently in various ligaments and tendons than originally expected. In the future, such amyloid deposits may aid determination of the pathogenesis of ligament and tendon disorders in older patients. PMID:21334722

Sueyoshi, Takanao; Ueda, Mitsuharu; Jono, Hirofumi; Irie, Hiroki; Sei, Akira; Ide, Junji; Ando, Yukio; Mizuta, Hiroshi

2011-02-21

240

Magnetic resonance imaging appearance of the shoulder after subacromial injection with corticosteroids can mimic a rotator cuff tear.  

PubMed

Subacromial injections have been used to treat rotator cuff problems. Previous studies have noted the difficulty in performing accurate injections into this area. In addition, one must also question the effects that misplaced corticosteroids could have on the surrounding tissues. In this case, a 51-year-old woman presented with several weeks of left shoulder pain and was diagnosed with rotator cuff tendonitis. After a subacromial injection with betamethasone and lidocaine, the patient noted 3 weeks of near complete pain relief, followed by a return of her symptoms. A magnetic resonance imaging scan obtained 7 weeks after the injection showed a full-thickness tear of the supraspinatus tendon. Five weeks later, the patient underwent arthroscopic evaluation of the shoulder and subacromial decompression. The rotator cuff tendons were noted to be intact and normal in appearance. The patient eventually had full resolution of her symptoms. Six months postoperatively, she underwent a new scan that showed a normal supraspinatus tendon. Apparently, the subacromial injection penetrated the anterior half of the supraspinatus tendon, causing a transient effect and signal change. One should use caution in the interpretation of magnetic resonance imaging scans of the shoulder soon after the injection of corticosteroids. PMID:18589276

Borick, Jay M; Kurzweil, Peter R

2007-04-24

241

Work-related lesions of the supraspinatus tendon: a case–control study  

Microsoft Academic Search

Objectives  To examine the dose–response relationship between cumulative duration of work with highly elevated arms (work above shoulder\\u000a level) as well as of manual material handling and ruptures of the supraspinatus tendon in a population-based case–control\\u000a study.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  In 14 radiologic practices, we recruited 483 male patients aged 25–65 with radiographically confirmed partial (n = 385) or total (n = 98) supraspinatus tears associated with shoulder

Andreas Seidler; Ulrich Bolm-Audorff; Gabriela Petereit-Haack; Elke Ball; Magdalena Klupp; Noëlle Krauss; Gine Elsner

2011-01-01

242

[Symptomatic rotator cuff tear of the shoulder].  

PubMed

Rotator cuff tears of the shoulder are common in the middle age and elderly population and can cause chronic pain. The prevalence of rotator cuff tears in people in their 50s, 60s, 70s, and 80s is 12.8%, 25.6%, 45.8% and 50% respectively. Etiological theories for tear evolvement are divided into intrinsic (e.g. recurrent microtrauma) and extrinsic (e.g. subacromial impingement). The subacromial bursa is probably the source of pain in symptomatic patients with rotator cuff tear. It is uncertain whether the tear itself can produce pain because of the high prevalence of asymptomatic tears. The symptoms are of gradual increase in shoulder pain and weakness, however, it can happen acutely due to an injury. Difficulties in overhead activities and night pain are common. Evaluation of shoulder muscle strength can imply on cuff tear. Shoulder radiograph is essential specifically to rule out other diagnosis. Imaging such as ultrasound and magnetic resonance can further define the tear, however they should be used only if they will affect the management of the condition. Common indications for surgical repair are acute tear in a relatively young and active patient or when the treatment of symptomatic patient with chronic tear had failed. Most repairs are currently performed in an all arthroscopic technique which is minimally invasive with easier rehabilitation and less pain. PMID:22741212

Haviv, Barak; Bronak, Shlomo; Thein, Rafael

2012-02-01

243

Transcription factor EGR1 directs tendon differentiation and promotes tendon repair.  

PubMed

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-?2. 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

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

2013-07-25

244

Tissue engineering for tendon repair  

Microsoft Academic Search

Tissue engineering aims to induce tissue self-regeneration in vivo or to produce a functional tissue replacement in vitro to be then implanted in the body. To produce a viable and functional tendon, a uniaxially orientated collagen type I matrix has to be generated. Biochemical and physical factors can potentially alter both the production and the organisation of this matrix, and

Pierre-Olivier Bagnaninchi; Ying Yang; Alicia J El Haj; Nicola Maffulli; U Bosch

2007-01-01

245

Arthroscopy of the shoulder in the management of partial tears of the rotator cuff: a preliminary report.  

PubMed

Thirty-six patients with partial tears of the supraspinatus portion of the rotator cuff underwent arthroscopic examination and debridement of the lesion. All patients, whose average age was 22 years, were involved in competitive athletics; 64% were baseball pitchers. The average duration of symptoms prior to arthroscopy was 12 months. The most common presenting complaint was pain felt in the shoulder during overhead activities. Associated pathology included tears of the glenoid labrum and partial tearing or tendinitis of the long head of the biceps tendon. Of the 34 patients available for follow-up, 26 (76%) had excellent results, three (9%) had good results, and five (15%) had poor results. Eighty-five percent of the patients returned satisfactorily to their preoperative athletic activity. Our preliminary experience with arthroscopy of the shoulder in the management of patients with partial rotator cuff tears is encouraging. Not only can a partial rotator cuff tear be debrided to initiate a healing response, but a definitive diagnosis can also be made and associated pathology identified, permitting the establishment of an appropriate rehabilitation program. PMID:4091915

Andrews, J R; Broussard, T S; Carson, W G

1985-01-01

246

Snapping knee caused by a popliteomeniscal fascicle tear of the lateral meniscus in a professional Taekwondo athlete.  

PubMed

A 19-year-old male professional Taekwondo athlete presented with a 2-year history of pain-free snapping of his right knee. He reported that his right knee joint gave way during games and training and that he could induce pain-free snapping between the proximal-to-fibular head and the lateral knee joint line. None of these physical findings suggested a meniscal pathology or ligamentous instability. Routine radiographs were normal. Magnetic resonance imaging of his right knee joint showed that the shape of the lateral meniscus was normal, and no lateral meniscus tears existed. On arthroscopic examination, popliteal hiatus view showed a posterosuperior popliteomeniscal fascicle tear between the posterior horn of the lateral meniscus and the posterior joint capsule just posteromedial to the popliteus tendon. With medial traction by probing, this popliteomeniscal tear made visible the significant subluxation of the posterior horn of the lateral meniscus to the center or anterior half of the tibial plateau. Based on the diagnosis of a posterosuperior popliteomeniscal tear of the right knee, Fast-Fix (Smith & Nephew, Andover, Massachusetts) was used for the direct repair of the peripheral portion of the lateral meniscus and joint capsule, targeting the popliteomeniscal junction. At 24 months postoperatively, the patient was performing athletic exercises relevant to his profession and was taking part in Taekwondo games, with no pain or recurrence of snapping. To the authors' knowledge, this is the first report of snapping of the lateral aspect of the knee due to a popliteomeniscal fascicle tear. PMID:22784909

Park, Jong-Hoon; Ro, Kyung-Han; Lee, Dae-Hee

2012-07-01

247

Nanoparticle-Induced Superior Hot Tearing Resistance of A206 Alloy  

NASA Astrophysics Data System (ADS)

Al- Cu alloys (such as A206) offer high strength and high fracture toughness at both room and elevated temperatures. However, their widespread applications are limited because of their high susceptibility to hot tearing. This article presents a nanotechnology approach to enhance hot-tearing resistance for A206. Specifically, ?-Al2O3 nanoparticles were used, and their effects on the hot-tearing resistance of the as-cast Al-4.5Cu alloy (A206) were investigated. While it is well known that grain refinement can improve the hot-tearing resistance of cast Al alloys, the current study demonstrated that nanoparticles can be much more effective in the case of A206. The hot-tearing susceptibilities (HTSs) of A206 alloy and its Al2O3 nanocomposite were evaluated by constrained rod casting (CRC) with a steel mold. Monolithic A206 and M206 (the Ti-free version of A206) alloys with the B contents of 20, 40, and 300 ppm from an Al-5Ti-1B master alloy addition were also cast under the same conditions for comparison. The results showed that with an addition of 1 wt pct ?-Al2O3 nanoparticles, the extent of hot tearing in A206 alloys was markedly reduced to nearly that of A356, an Al-Si alloy highly resistant to hot tearing. As compared with grain-refined A206 or M206, the hot-tearing resistance of the nanocomposites was significantly better, even though the grain size was not reduced as much. Microstructural analysis suggested that ?-Al2O3 nanoparticles modified the solidification microstructure of the eutectic of ?-Al2Cu and ?-Al, as well as refined primary grains, resulting in the enhancement of the hot-tearing resistance of A206 to a level similar to that of A356 alloy.

Choi, Hongseok; Cho, Woo-hyun; Konishi, Hiromi; Kou, Sindo; Li, Xiaochun

2013-04-01

248

Computational modeling of neoclassical and resistive MHD tearing modes in tokamaks  

SciTech Connect

Numerical studies of the nonlinear evolution of MHD-type tearing modes in three-dimensional toroidal geometry with neoclassical effects are presented. The inclusion of neoclassical physics introduces an additional free-energy source for the nonlinear formation of magnetic islands through the effects of a bootstrap current in Ohm`s law. The neoclassical tearing mode is demonstrated to be destabilized in plasmas which are otherwise {Delta}` stable, albeit once an island width threshold is exceeded. The plasma pressure dynamics and neoclassical tearing growth is shown to be sensitive to the choice of the ratio of the parallel to perpendicular diffusivity ({Chi}{parallel}/{Chi}{perpendicular}). The study is completed with a demonstration and theoretical comparison of the threshold for single helicity neoclassical MHD tearing modes, which is described based on parameter scans of the local pressure gradient, the ratio of perpendicular to parallel pressure diffusivities {Chi}{perpendicular}/{Chi}{parallel}, and the magnitude of an initial seed magnetic perturbation.

Gianakon, T.A.; Hegna, C.C.; Callen, J.D.

1996-06-24

249

Cell and matrix changes associated with pathological calcification of the human rotator cuff tendons.  

PubMed Central

The causative mechanism of tendon calcification ('calcifying tendinitis') is unknown. In this report, pathological human tendon samples were examined to give morphological and ultrastructural detail of the calcified regions and these findings were compared with those from normal tendon. Selected specimens were cryosectioned to enable histochemical and immunohistochemical comparison of the occurrence and distribution of specific matrix molecules in diseased and normal tendon tissues. The lack of collagen type II and alkaline phosphatase in the pathological regions suggests that the calcification process is not mediated through an endochondral transition. In contrast, the pathological areas were characterised by widespread labelling for chondroitin-4-sulphate/dermatan sulphate and intense pericellular localisation of chondroitin-6-sulphate. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9

Archer, R S; Bayley, J I; Archer, C W; Ali, S Y

1993-01-01

250

Anterior cruciate ligament injury: Evaluation of intraarticular reconstruction of acute tears without repairTwo to seven year followup of 155 athletes  

Microsoft Academic Search

To evaluate the effectiveness of our treatment regimen, we retrospectively studied the surgically treated knees of 155 athletes, aged 15 to 42 years, who had sustained acute ACL tears. All were treated with ligament excision and intraarticular bone-patellar tendon-bone recon struction followed by early motion with emphasis on full extension. The follow-up period ranged from 2 to 7 years. Of

K. Donald Shelbourne; H. Jeffrey Whitaker; John R. McCarroll; Arthur C. Rettig; Lynne D. Hirschman

1990-01-01

251

Human tendon behaviour and adaptation, in vivo  

PubMed Central

Tendon properties contribute to the complex interaction of the central nervous system, muscle–tendon unit and bony structures to produce joint movement. Until recently limited information on human tendon behaviour in vivo was available; however, novel methodological advancements have enabled new insights to be gained in this area. The present review summarizes the progress made with respect to human tendon and aponeurosis function in vivo, and how tendons adapt to ageing, loading and unloading conditions. During low tensile loading or with passive lengthening not only the muscle is elongated, but also the tendon undergoes significant length changes, which may have implications for reflex responses. During active loading, the length change of the tendon far exceeds that of the aponeurosis, indicating that the aponeurosis may more effectively transfer force onto the tendon, which lengthens and stores elastic energy subsequently released during unloading, in a spring-like manner. In fact, data recently obtained in vivo confirm that, during walking, the human Achilles tendon provides elastic strain energy that can decrease the energy cost of locomotion. Also, new experimental evidence shows that, contrary to earlier beliefs, the metabolic activity in human tendon is remarkably high and this affords the tendon the ability to adapt to changing demands. With ageing and disuse there is a reduction in tendon stiffness, which can be mitigated with resistance exercises. Such adaptations seem advantageous for maintaining movement rapidity, reducing tendon stress and risk of injury, and possibly, for enabling muscles to operate closer to the optimum region of the length–tension relationship.

Magnusson, S Peter; Narici, Marco V; Maganaris, Constantinos N; Kjaer, Michael

2008-01-01

252

Collisionless tearing modes in the presence of shear flow  

NASA Astrophysics Data System (ADS)

Tearing modes in a plane collisionless current sheet with shear bulk flow are investigated. An analytic expression for the growth rate is obtained, noting that the growth rates are larger and the unstable wave number domain is increased in comparison with the case without flow. Attention is given to the relevance of these results to time-dependent reconnection processes in the earth's magnetosphere. It is pointed out that the results obtained may have a bearing on applications in space physics. Even though in the near-earth plasma sheet the normal magnetic field component, which is present already in the equilibrium, rules out the electron tearing mode treated here, this might not be true in the far tail. There, one can expect the normal component to be extremely small and the flow to become more important than is the case closer to the earth.

Lakhina, G. S.; Schindler, K.

1983-01-01

253

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

PubMed Central

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 obtain their biomechanical properties. Specifically, we hope the reader will pay attention to how the properties of these tissues can be altered due to various experimental and biologic factors. Following this background material, we will present how biomechanics can be applied to gain an understanding of the mechanisms as well as clinical management of various ligament and tendon ailments. To conclude, new technology, including imaging and robotics as well as functional tissue engineering, that could form novel treatment strategies to enhance healing of ligament and tendon are presented.

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

2009-01-01

254

Mesenchymal stem cell applications to tendon healing  

PubMed Central

Summary Tendons are often subject to age related degenerative changes that coincide with a diminished regenerative capacity. Torn tendons often heal by forming scar tissue that is structurally weaker than healthy native tendon tissue, predisposing to mechanical failure. There is increasing interest in providing biological stimuli to increase the tendon reparative response. Stem cells in particular are an exciting and promising prospect as they have the potential to provide appropriate cellular signals to encourage neotendon formation during repair rather than scar tissue. Currently, a number of issues need to be investigated further before it can be determined whether stem cells are an effective and safe therapeutic option for encouraging tendon repair. This review explores the in-vitro and invivo evidence assessing the effect of stem cells on tendon healing, as well as the potential clinical applications.

Chaudhury, Salma

2012-01-01

255

Effect of therapeutic ultrasound on tendons.  

PubMed

Ultrasound is a therapeutic agent commonly used to treat sports-related musculoskeletal conditions, including tendon injuries or tendinopathy. Despite the widespread popularity of therapeutic ultrasound, few clinical studies have proved its efficacy. Several animal studies have been conducted to explore its effectiveness. In addition, a number of in vitro studies investigating the mechanisms underlying the ability of this physical modality to enhance tendon healing or to treat tendinopathy are in progress. There is strong supporting evidence from animal studies about the positive effects of ultrasound on tendon healing. In vitro studies have also demonstrated that ultrasound can stimulate cell migration, proliferation, and collagen synthesis of tendon cells that may benefit tendon healing. These positive effects of therapeutic ultrasound on tendon healing revealed by in vivo and in vitro studies help explain the physiologic responses to this physical modality and could serve as the foundation for clinical practice. PMID:21552108

Tsai, Wen-Chung; Tang, Sf-T; Liang, Fang-Chen

2011-12-01

256

Investigating tendon mineralisation in the avian hindlimb: a model for tendon ageing, injury and disease.  

PubMed

Mineralisation of the tendon tissue has been described in various models of injury, ageing and disease. Often resulting in painful and debilitating conditions, the processes underlying this mechanism are poorly understood. To elucidate the progression from healthy tendon to mineralised tendon, an appropriate model is required. In this study, we describe the spontaneous and non-pathological ossification and calcification of tendons of the hindlimb of the domestic chicken (Gallus gallus domesticus). The appearance of the ossified avian tendon has been described previously, although there have been no studies investigating the developmental processes and underlying mechanisms leading to the ossified avian tendon. The tissue and cells from three tendons - the ossifying extensor and flexor digitorum longus tendons and the non-ossifying Achilles tendon - were analysed for markers of ageing and mineralisation using histology, immunohistochemistry, cytochemistry and molecular analysis. Histologically, the adult tissue showed a loss of healthy tendon crimp morphology as well as markers of calcium deposits and mineralisation. The tissue showed a lowered expression of collagens inherent to the tendon extracellular matrix and presented proteins expressed by bone. The cells from the ossified tendons showed a chondrogenic and osteogenic phenotype as well as tenogenic phenotype and expressed the same markers of ossification and calcification as the tissue. A molecular analysis of the gene expression of the cells confirmed these results. Tendon ossification within the ossified avian tendon seems to be the result of an endochondral process driven by its cells, although the roles of the different cell populations have yet to be elucidated. Understanding the role of the tenocyte within this tissue and the process behind tendon ossification may help us prevent or treat ossification that occurs in injured, ageing or diseased tendon. PMID:23826786

Agabalyan, Natacha A; Evans, Darrell J R; Stanley, Rachael L

2013-07-05

257

Muscle Force and Power Following Tendon Repair at Altered Tendon Length  

PubMed Central

Background While a great deal is known regarding the performance of muscle with intact tendon, little is known about muscle performance when tendon is surgically lengthened or shortened. This knowledge may allow surgeons to more accurately predict functional outcome following tendon repair when correcting a simple tendon laceration or performing a more complex vascularized neuromuscular transfer. Materials and Methods We studied muscle performance 12 weeks following extensor tendon repairs producing altered tendon lengths. Forty male Fischer 344 rats underwent division of the proximal and distal tendons of the extensor digitorum longus muscle. Tendons were immediately repaired producing tendons with increased length, decreased length, or pre-surgical length (control). Observation confirmed that altered tendon length produced inverse changes in initial resting muscle tension. Results Muscle in the Decreased Tendon Length group demonstrated a 15.2% greater muscle mass, 4.9% greater muscle length, 9.6% greater physiologic cross-sectional area, 12.6% greater maximum isometric force, and 31.9% greater maximum power relative to the Control Tendon Length group (p < 0.05). The Increased Tendon Length group did not differ significantly from the Control Tendon Length group for any measurement. Histologically, muscles set with a decreased tendon length demonstrated normal appearing hypertrophied fibers, without evidence of detrimental histological effects such as fibrosis, denervation, necrosis, inflammation, fiber type changes, or fiber splitting. Conclusion These data support the clinical practice of setting muscles with increased passive tension when performing tendon transfer surgeries. Conversely, setting muscles with decreased tension does not necessarily result in a force or power deficit.

Krochmal, Daniel J.; Kuzon, William M.; Urbanchek, Melanie G.

2008-01-01

258

Intraarticular fibroma of tendon sheath  

PubMed Central

A 17-year-old male presented to us following a hyperflexion injury to his right knee sustained while playing soccer. Immediately after the traumatic event, he developed a large, tense knee effusion. Physical examination revealed limited range of motion. MRI revealed a lobulated mass in the posteromedial aspect of the knee joint. The mass was excised and sections submitted to pathology. A pathologic, microscopic, and immunohistochemical characteristics revealed the final diagnosis of fibroma of tendon sheath in the knee. At 12 months followup, the patient reported no subjective symptoms, such as pain or limitation of athletic activities and has full range of motion. Additionally, he has demonstrated no signs of recurrence. We report a case of fibroma of the tendon sheath originating from the synovial membrane of the joint capsule of the knee.

Griesser, Michael J; Wakely, Paul E; Mayerson, Joel

2011-01-01

259

Association of peripheral vertical meniscal tears with anterior cruciate ligament tears  

Microsoft Academic Search

Objective  The purpose of this article is to describe a type of meniscal tear seen on magnetic resonance (MR) imaging, the peripheral\\u000a vertical tear, and to determine the prevalence of anterior cruciate ligament (ACL) tears in knees with this type of meniscal\\u000a tear compared to knees with other types of meniscal tears.\\u000a \\u000a \\u000a \\u000a Materials and methods  Following Institutional Review Board approval, a retrospective

Emily N. Vinson; Jeffrey A. Gage; Joe N. Lacy

2008-01-01

260

Percutaneous Z Tendon Achilles Lengthening  

Microsoft Academic Search

\\u000a Achilles tendon lengthening is a delicate procedure whereby the risk of over lengthening (creating calcaneus), rupture, and\\u000a weakening of the gastrocnemius-soleus muscle is devastating. The Silfverskiöld test is clinically performed to differentiate\\u000a gastrocnemius equinus from gastrocnemius-soleus equinus. Many surgical techniques have been developed to treat negative results\\u000a of the Silfverskiöld test. The authors prefer a gastrocnemius-soleus recession in order to

Bradley M. Lamm; Dror Paley

261

Structure and function of tuna tail tendons.  

PubMed

The caudal tendons in tunas and other scombrid fish link myotomal muscle directly to the caudal fin rays, and thus serve to transfer muscle power to the hydrofoil-like tail during swimming. These robust collagenous tendons have structural and mechanical similarity to tendons found in other vertebrates, notably the leg tendons of terrestrial mammals. Biochemical studies indicate that tuna tendon collagen is composed of the (alpha1)(2),alpha2 heterotrimer that is typical of vertebrate Type I collagen, while tuna skin collagen has the unusual alpha1,alpha2,alpha3 trimer previously described in the skin of some other teleost species. Tuna collagen, like that of other fish, has high solubility due to the presence of an acid-labile intermolecular cross-link. Unlike collagen in mammalian tendons, no differences related to cross-link maturation were detected among tendons in tuna ranging from 0.05 to 72 kg (approx. 0.25-6 years). Tendons excised post-mortem were subjected to load cycling to determine the modulus of elasticity and resilience (mean of 1.3 GPa and 90%, respectively). These material properties compare closely to those of leg tendons from adult mammals that can function as effective biological springs in terrestrial locomotion, but the breaking strength is substantially lower. Peak tendon forces recorded during steady swimming appear to impose strains of much less than 1% of tendon length, and no more than 1.5% during bursts. Thus, the caudal tendons in tunas do not appear to function as elastic storage elements, even at maximal swimming effort. PMID:12485695

Shadwick, Robert E; Rapoport, H Scott; Fenger, Joelle M

2002-12-01

262

Intrarectal tear from water skiing.  

PubMed

We report a case of intrarectal tear and hemorrhage after a fall while water skiing. The injury resulted from rectal douche, or jet enema, which is dangerous because of the high pressure of the water jets forced into the rectum. The patient, a middle-aged woman, had colonoscopy, which revealed a deep rectal laceration. During subsequent colostomy, a full-thickness laceration and an extensive pelvic and retroperitoneal hematoma with some free blood were found. The patient's recovery was uneventful, and she subsequently had reanastomosis of her colostomy. We recommend protective apparel to prevent these injuries. PMID:1595660

Lee, R Y; Miller, S; Thorpe, C

1992-05-01

263

Technique for and an anatomic guide to forearm tendon repair.  

PubMed

Forearm lacerations involving muscle bellies are usually treated by repairing muscle fascia. Repair of tendons themselves is stronger and restores normal muscle anatomy better. Tendon repair requires good knowledge of forearm muscle and tendon anatomy. We have made cadaver measurements to produce graphical maps of locations of individual muscles tendons of origin and insertion, some practical guides for finding tendon ends and a simple grasping stitch for intramuscular tendons. PMID:21606787

Burnham, Jeremy M; Hollister, Anne M; Rush, David A; Avallone, Thomas J; Shi, Runhua; Jordan, Jenee' C

2011-06-01

264

Histopathological findings in spontaneous tendon ruptures.  

PubMed

A spontaneous rupture of a tendon may be defined as a rupture that occurs during movement and activity, that should not and usually does not damage the involved musculotendinous units (1). Spontaneous tendon ruptures were uncommon before the 1950s. Böhler found only 25 Achilles tendon ruptures in Wien between 1925 and 1948 (2). Mösender & Klatnek treated 20 Achilles tendon ruptures between 1953 and 1956, but 105 ruptures between 1964 and 1967 (3). Lawrence et al. found only 31 Achilles tendon ruptures in Boston during a period of 55 years (1900-1954) (4). During the recent decades tendon ruptures have, however, become relatively common in developed countries, especially in Europe and North America. A high incidence of tendon ruptures has been reported in Austria, Denmark, Finland, Germany. Hungary, Sweden, Switzerland and the USA; somewhat lower incidences have been reported in Canada, France, Great Britain and Spain. On the other hand, Greece, Japan, the Netherlands and Portugal have reported a clearly lower incidence. Interestingly, Achilles tendon ruptures are a rarity in developing countries, especially in Africa and East-Asia (5). In many developed countries, the increases in the rupture incidence have been dramatic. In the National Institute of Traumatology in Budapest, Hungary, the number of patients with an Achilles tendon rupture increased 285% in men and 500% in women between two successive 7-year periods, 1972-1978 and 1979-1985 (5). PMID:9211612

Józsa, L; Kannus, P

1997-04-01

265

Pectoralis Major Tendon Repair Post Surgical Rehabilitation  

PubMed Central

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.

Prohaska, Dan

2007-01-01

266

Triceps tendon rupture in weight lifters.  

PubMed

Triceps tendon avulsion injuries are rare. We report four weight lifters with triceps tendon raptures, two of whom had received local steroid injections for pain in the triceps. All four patients had taken oral anabolic steroids before injury. All patients had closed avulsion of the triceps tendon from its insertion into the olecranon. Three patients were injured while bench pressing heavy weights, and one patient was injured while swinging a baseball bat. Satisfactory results were achieved after surgical reinsertion of the tendon. PMID:9593095

Sollender, J L; Rayan, G M; Barden, G A

267

Tendon Regeneration and Repair with Stem Cells  

PubMed Central

The use of stems cells in tendon repair is of particular interest given the frequency of tendon injuries worldwide together with the technical difficulty often encountered when repairing or augmenting tendons. Stems cells have the capability to differentiate into a variety of different cell types including osteocytes and tenocytes, and if normal architecture of damaged tendon (either macroscopic or microscopic) could be restored, this would significantly improve the management of patients with these injuries. There is already encouraging research on the use of stems cells clinically although considerable further work is required to improve knowledge and clinical applications of stem cells in tissue engineering.

MacLean, S.; Khan, W. S.; Malik, A. A.; Snow, M.; Anand, S.

2012-01-01

268

Arthroscopic surgery for partial rotator cuff tears  

Microsoft Academic Search

Rotator cuff pathology is one of the most common disorders of the shoulder. However, partial rotator cuff tears, treatment, and natural history are still in a state of flux. We believe that partial rotator cuff tears should be treated surgically when the rotator cuff is torn more than 50% of the thickness or when substantial thinning of the rotator cuff

Richard C Lehman; Clayton R Perry

2003-01-01

269

Giant retinal tears after pars plana vitrectomy  

Microsoft Academic Search

Vitreous surgery is used to treat complicated vitreo-retinal pathology. Retinal tears are a serious complication of vitreous surgery. In this report, the development of giant retinal tears in four eyes after pars plana vitrectomy for posterior segment pathology is described. The pathogenesis and implications of this serious and infrequent complication are discussed.

Ahmed M Abu El-Asrar

1997-01-01

270

Suturing a tear of the anterior capsulorhexis  

PubMed Central

Aim To describe a new technique of suturing a tear in the anterior capsulorhexis. Methods Continuous curvilinear capsulorhexis (CCC) with lens removal was done in five fresh cadaver eyes. The diameter of the CCC was measured with a calliper. Using the same calliper a tear of the CCC was created while opening the calliper's arms. The distance between the calliper's arms needed to tear the CCC was documented. Using 9?0 Ethilon 9011, CS 160?6 sutures in two eyes, 9?0 Prolene, D?8229, CTC?6L sutures in two eyes, and 10?0 Prolene, 9090, CTC?6 suture in one eye, the tears were sutured. A tear in the CCC was created again in the same way as the first tear. The distance between the calliper's arms needed to tear the CCC was documented again. Results Suturing of the tear restored some of the strength/elasticity of the CCC. Better results were found while using the 9?0 Prolene, D?8229, CTC?6L sutures than with the two others sutures. Conclusions Suturing of a broken CCC can restore at least some of the strength/elasticity of the CCC. This can be important before intraocular lens (IOL) implantation for the safety of the implantation or after the implantation to ensure proper fixation of the IOL.

Kleinmann, G; Chew, J; Apple, D J; Assia, E I; Mamalis, N

2006-01-01

271

Raman point mapping of tear ferning patterns  

NASA Astrophysics Data System (ADS)

This study attempts to combine the tear ferning test and the drop coating deposition Raman spectroscopy (DCDRS) technique to analyze the biochemical composition of human tear fluid from healthy volunteers. DCDRS has been shown to be a highly reproducible and sensitive method of obtaining Raman spectra from low concentration protein solutions making it ideal for the analysis of tear fluid. On drying, tear samples were found to produce ring-shaped patterns, which are characteristic of the DCDRS technique, with additional fern-like structures produced inside the rings. The biochemical composition of the each drying pattern was studied by Raman point mapping and principal components analysis. Assignment of high-signal-to-noise tear spectra showed that tear proteins, urea, bicarbonate and lipid components were all present in the dried tear drop. Comparing an image time series of the drying process with the biochemical distributions from the Raman point map revealed the order of biochemical deposition in the drying pattern. The combination of DCDRS and the tear ferning test shows enough promise to be further studied as a near-patient technique for assisting the diagnosis of ocular infection, but further work is required to validate the technique.

Filik, Jacob; Stone, Nicholas

2008-03-01

272

Locked bucket-handle meniscal tears in knees with chronic anterior cruciate ligament deficiency.  

PubMed

Because we noticed patients had difficulty regaining full range of motion after surgery for a locked bucket-handle meniscal tear with simultaneous reconstruction for a chronic anterior cruciate ligament tear, we adopted a two-stage procedure for this group of patients. We evaluated the results of a two-stage procedure in the knees of 16 athletes (Group 1) and compared their outcome with the outcome of 16 matched athletes who had been treated with simultaneous repair or removal of the displaced bucket-handle meniscal tear and autogenous patellar tendon anterior cruciate ligament reconstruction (Group 2). Four patients in Group 2 required a second procedure or casting to regain full extension. No patient in Group 1 required a second procedure. One meniscal retear was detected in Group 1. The two-stage procedure also appears to have a number of theoretical advantages: 1) more aggressive use of repair rather than removal of a displaced torn meniscus, 2) prevention of problems in regaining range of motion, 3) allows a second look to judge the success of meniscal repair, and 4) allows time for the patient to prepare for anterior cruciate ligament reconstruction physically, mentally, academically, and socially. PMID:8291626

Shelbourne, K D; Johnson, G E

273

MRI-negative bucket-handle tears of the lateral meniscus in athletes: a case series.  

PubMed

Magnetic resonance imaging (MRI) is the most widely used non-invasive test for assessing intra-articular injuries of the knee. It has been suggested that a negative MRI can be useful in avoiding the need for diagnostic arthroscopy in cases where clinical examination is equivocal. However, the sensitivity and specificity of MRI is not 100%, particularly for tears of the lateral meniscus. Furthermore, a false negative MRI scan may result in premature return to play in athletes, resulting in increased risk of further damage to a torn meniscus. To illustrate this issue, we present a case series of eight elite athletes who all presented with mechanical knee symptoms and where MRI scans revealed no significant intra-articular pathology. Five of the athletes were allowed to return to sport on the basis of a negative MRI. All patients were subsequently found to have a bucket-handle tear of their lateral meniscus at arthroscopy. Two independent, experienced musculoskeletal radiologists were asked to review the MRI films without being given any clinical history of the cases. Although injuries to the popliteus tendon were noted in two of the athletes who had sustained a recent acute injury to their knee, no meniscal tears were identified. Thus arthroscopy remains the gold standard for the assessment and management of high-demand patients with a clinical suspicion of meniscal pathology. PMID:16311767

Makdissi, Michael; Eriksson, Karl O; Morris, Hayden G; Young, David A

2005-11-26

274

Tear ferning in contact lens wearers.  

PubMed

Tear ferning (TF) has shown good sensitivity and specificity in the diagnosis of dry eye, but is a relatively uncommon test, especially in contact lens wearers. The aim of this study was to investigate the relationship between TF, ocular comfort and tear film stability amongst contact lens (CL) wearers and non-contact lens (NCL) wearers. Subjects (36 NCL, 24 CL; mean age 23.2 +/- 4.8 years) underwent assessment of non-invasive tear break up time (NIBUT), fluorescein tear break up time (FBUT) and completed the Ocular Comfort Index (OCI) questionnaire. Non-stimulated tears were collected from the inferior tear meniscus with a glass capillary. Samples of 1.5 microL were air dried, observed by light microscopy and the TF pattern quantified according to Rolando's grading scale. Significantly higher grades of TF pattern and discomfort (higher OCI scores) were observed in CL wearers compared to NCL wearers (Mann-Whitney U-test; p < 0.005 and p < 0.05 respectively). Differences in tear film stability were not significant between groups. Even when asymptomatic (low OCI scores) CL and NCL subjects were compared, TF remained significantly different (p < 0.005). In both CL and NCL subjects, TF displayed poor correlation with tear film stability tests and OCI scores. Higher TF grades in CL wearers, even if asymptomatic, indicate an unfavourable ratio of salt to macromolecule concentration within the tear film of such subjects. The lack of significant difference in TF between symptomatic CL and NCL wearers could suggest similar aetiology (tear film hyperosmolarity) in each cohort. The TF technique demonstrates limited sensitivity and specificity for the prediction of ocular surface comfort in both CL and NCL wearers. PMID:19236590

Evans, Katharine S E; North, Rachel V; Purslow, Christine

2009-03-01

275

Elastic properties of the cat soleus tendon and their functional importance.  

PubMed Central

A new method has been used to measure the stiffness of the entire tendinous component of the soleus muscle of the cat. During sinusoidal stretching of the muscle-tendon combination, the motor nerves were stimulated repetitively in such a way that the force of contraction offset the movement, and the muscle fibres remained at constant length. The afferent endings of muscle spindles were used to detect extension of the muscle fibres. In this null situation, when the spindles did not 'see' any movement, all of the applied movement was assumed to have been taken up in the tendinous components, and measurements of the movement and force allowed the stiffness to be calculated. Precautions were taken to avoid the effects of fusimotor stimulation. The stiffness of the entire tendinous component increased with increasing muscle force by approximately 2 N/mm per Newton mean force from 2 N/mm at low force to about 25 N/mm at 11 N; the method could not be used for larger forces. Independent measurements of the stiffness of the external part of the tendon were made by both static and dynamic methods. The entire tendinous component was much less stiff than the external tendon. Measurements of the dimensions of the tendon allowed Young's modulus for the tendon to be calculated. It increased from about 250 N/mm2 at 2.5 N to about 450 N/mm2 at 10 N mean force. Measurements of dissected muscles allowed comparisons to be made between the stiffness of the external tendon and the stiffness of the entire tendinous component in the muscles. Scaling of the stiffness of the external part of the tendon to the length of the entire tendinous component gave a value of stiffness which was similar to that measured by the spindle null method. The compliance of tendons has implications for the control of movement which are discussed.

Rack, P M; Westbury, D R

1984-01-01

276

Tendon mineralization is accelerated bilaterally and creep of contralateral tendons is increased after unilateral needle injury of murine achilles tendons.  

PubMed

Heterotopic mineralization may result in tendon weakness, but effects on other biomechanical responses have not been reported. We used a needle injury, which accelerates spontaneous mineralization of murine Achilles tendons, to test two hypotheses: that injured tendons would demonstrate altered biomechanical responses; and that unilateral injury would accelerate mineralization bilaterally. Mice underwent left hind (LH) injury (I; n?=?11) and were euthanized after 20 weeks along with non-injured controls (C; n?=?9). All hind limbs were examined by micro computed tomography followed by biomechanical testing (I?=?7 and C?=?6). No differences were found in the biomechanical responses of injured tendons compared with controls. However, the right hind (RH) tendons contralateral to the LH injury exhibited greater static creep strain and total creep strain compared with those LH tendons (p???0.045) and RH tendons from controls (p???0.043). RH limb lesions of injured mice were three times larger compared with controls (p?=?0.030). Therefore, despite extensive mineralization, changes to the responses we measured were limited or absent 20 weeks postinjury. These results also suggest that bilateral occurrence should be considered where tendon mineralization is identified clinically. This experimental system may be useful to study the mechanisms of bilateral new bone formation in tendinopathy and other conditions. PMID:23754538

O'Brien, Etienne John Ogilvy; Shrive, Nigel G; Rosvold, Joshua M; Thornton, Gail M; Frank, Cyril B; Hart, David A

2013-06-10

277

Subscapularis Tendon Integrity: An Examination of Shoulder Index Tests  

PubMed Central

Abstract Reference: Hegedus EJ, Goode A, Campbell S, et al. Physical examination tests of the shoulder: a systematic review with meta-analysis of individual tests. Br J Sports Med. 2008;42(2):80–92. Clinical Question: The systematic review focused on various index tests for the shoulder. We concentrated on the subscapularis tendon results to determine the accuracy of reported index tests for clinically diagnosing subscapularis integrity. Data Sources: Studies were identified by an OVID search using MEDLINE, SPORTDiscus, and CINHAL databases (1966–2006) and a hand search by 2 authors (E.J.H. and S.C.). Primary search terms were shoulder, examination, and diagnosis. In addition to the database searches, personal files were hand searched by one of the authors (E.J.H.) for publications, posters, and abstracts. The reference lists in review articles were cross-checked, and all individual names of each special test were queried using MEDLINE and PubMed. Study Selection: The search was limited to English-language journals. Studies were eligible for inclusion if the criterion standard was surgery, magnetic resonance imaging, or injection (subacromial or acromioclavicular joint); at least 1 physical examination test or special test was studied; and one of the paired statistics of sensitivity and specificity was reported or could be determined. Excluded were studies in which the index test was performed under anesthesia or in cadavers, studies in which the index test was assigned the status of composite physical examination, and review articles. Studies were grouped according to the subscapularis index test assessed: lift off, internal-rotation lag sign, Napoleon sign, bear hug, belly off, and belly press. Data Extraction: Studies were selected in a 2-stage process. First, all abstracts and articles found through the search process were independently reviewed by 2 authors (E.J.H. and S.C.). Disagreement on inclusion of an article was resolved by consensus. Second, each selected study was assessed by each reviewer independently. A third reviewer made the final decision on any disagreements for the selected studies. The primary outcome measures were sensitivity and specificity and positive and negative likelihood ratios. The quality of a study was determined by assessing its internal and external validity. Validity was determined by the primary author (E.J.H.) using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) statement. Our work required data extraction from the original articles, which we used to generate 2 × 2 contingency tables for each index test. Pooled indices of clinical usefulness were then determined for each index test. Main Results: The specific search criteria identified 922 articles for review. Of these, 4 met the inclusion and exclusion criteria for subscapularis tendon tears, resulting in the number of studies assessing each index test as follows: 4 for lift off, 2 for internal-rotation lag sign, 2 for Napoleon sign, 1 for bear hug, 1 for belly off, and 1 for belly press. Subscapularis tears were identified by the criterion standard of surgery to visually assess the torn fibers. Across all 4 studies, a total of 304 shoulders were examined, 95 of which had a subscapularis tear (45 full thickness, 50 partial thickness), and 106 were injury free. Indices of clinical usefulness for full-thickness and partial-thickness subscapularis tears are reported in Tables 1 and 2, respectively.

Rigsby, Ruel; Sitler, Michael; Kelly, John D.

2010-01-01

278

Proteomic analysis of the tear film in patients with keratoconus  

PubMed Central

Purpose To identify proteins differentially expressed between the tear film of keratoconus (KC) patients and control subjects using two dimensional electrophoresis (2-DE) and mass spectrometry-based techniques. Methods Twenty two patients (44 eyes) diagnosed with bilateral KC and 22 control subjects (44 eyes) were studied in a prospective case-control study. Keratoconus screening programs and Orbscan II topographies were performed on all participants. Tear samples were collected by the Schirmer I method using filter paper. Proteins were extracted from the Schirmer strips and separated by 2-DE. Comparison of protein patterns was performed using PDQuest Software and protein differences were identified by mass spectrometry. Finally, results were validated by western-blot. Results Four spots were identified to be differentially expressed between KC patients and control subjects. Three of them were more expressed in healthy subjects and they were identified as zinc-?2-glycoprotein (ZAG), lactoferrin, and IGKC (immunoglobulin kappa chain). The other spot was more expressed in KC patients and it was identified as ZAG. Differences in ZAG seem controversial in two different spots because different posttranslational modifications, however, analysis of both spots revealed that globally, ZAG is overexpressed in healthy subjects. Founded differences in ZAG, lactoferrin, and IGKC expression were subsequently validated by western blot. Conclusions IGKC protein, ZAG, and lactoferrin are under-expressed in the tears of patients diagnosed with bilateral KC compared with healthy subjects. These differences could contribute to the knowledge of the pathophysiology of this disease.

Brea, David; Rodriguez-Gonzalez, Raquel; Diez-Feijoo, Elio; Sobrino, Tomas

2010-01-01

279

Tear mucus ferning in patients with Sjögren's syndrome.  

PubMed

The purpose of this study is to evaluate the possibility of using the mucus ferning phenomenon of the tears as a diagnostic test for Keratoconjunctivitis sicca in patients with Sjögren's syndrome. Using a polarising light microscope dried samples were tested for ferning phenomenon collected from (1) 36 healthy controls, (2) 21 patients with primary Sjögren's syndrome, and (3) 15 patients with secondary Sjögren's syndrome. Patients with Sjögren's had xerostomia, abnormal salivary gland biopsy and at least two positive tests for Kerato-conjunctivitis sicca. Patterns of mucus crystallization were classified into 5 types according to uniformity, branch spreading and integrity (types I, II normal, types III, IV, V abnormal). Abnormal ferning was found in tear samples of 8 out of 72 normal control eyes, 38 out of 42 with primary Sjögren's syndrome and 25 out of 30 with secondary Sjögren's syndrome. The differences between both primary and secondary Sjögren's syndrome, in comparison to healthy controls, were significant (p < 0.001). The sensitivity of the method was found 90% for primary Sjögren's syndrome and 80% for secondary Sjögren's syndrome. According to our data, tear mucus ferning test is a simple, sensitive and specific test to estimate Keratoconjunctivitis sicca in patients with Sjögren's syndrome. PMID:7835183

Vaikoussis, E; Georgiou, P; Nomicarios, D

1994-01-01

280

Calcific tendonitis of the tibialis posterior tendon at the navicular attachment  

PubMed Central

Calcific tendinosis (tendonosis/tendonitis) is a condition which results from the deposition of calcium hydroxyapatite crystals in any tendon of the body. Calcific tendonitis usually presents with pain, which can be exacerbated by prolonged use of the affected tendon. We report a case of calcific tendinosis in the posterior tibialis tendon at the navicular insertion. The pathology is rare in the foot, and extremely rare in the tibialis posterior tendon, indeed there are only 2 reported in the published literature. This case report highlights the need to consider calcific tendinosis in the foot despite its rarity. If this diagnosis is considered early, appropriate investigations can then be requested and unnecessary biopsies, use of antibiotics and surgery can be avoided. We also discuss possible causes of calcific tendinosis in the tibialis posterior tendon, the role of imaging modalities and review treatment methods.

Harries, Luke; Kempson, Susan; Watura, Roland

2011-01-01

281

Effect of prostaglandin analogues on tear proteomics and expression of cytokines and matrix metalloproteinases in the conjunctiva and cornea  

Microsoft Academic Search

The purpose of this work was to identify potential tear-film-based proteins and their effect on changes in the conjunctiva and cornea in eyes using prostaglandin (PG) analogues. Recruited subjects were individuals who had used PG for at least 1 year and comparison with eyes of normal controls and timolol using patients were done. Approximately 3–5 ?L of tears were sampled from

Hae-Young Lopilly Park; Jie Hyun Kim; Kyung Min Lee; Chan Kee Park

282

Posterior tibial tendon rupture in athletic people  

Microsoft Academic Search

We present our findings in six athletic patients with a ruptured or partially ruptured posterior tibial tendon. Pain in the midarch region, difficulty pushing off while running, and a pronated flattened longitudinal arch are the usual symptoms and physical findings of this injury. Surgical treatment, including reattachment of the rup tured posterior tibial tendon, is effective in restoring some but

Lee Woods; Robert E. Leach

1991-01-01

283

Retropharyngeal Calcific Tendonitis: Report of Two Cases  

Microsoft Academic Search

Retropharyngeal calcific tendonitis is an inflammatory process of the superior oblique tendons of the longus colli muscle, a neck flexor in the upper cervical spine, caused by deposition of calcium hydroxy- apatite crystals; the definitive diagnostic test is computed tomography (CT). Presented in this article are two cases seen at our institution. Patients typically present with acute onset of neck

Rhea Victoria; B. Razon; Asad Nasir; George S. Wu; Manal Soliman; Jeffrey Trilling

284

Prestress Tendons On Short Radius Curves.  

National Technical Information Service (NTIS)

This report discusses the friction factor and ultimate tensile strength achieved by multi-strand tendons stressed around short radius curves. It was found that a pre-fabricated tendon of as many as 33 one-half-inch diameter strands, stressed through 1.7 r...

T. J. Bezouska

1975-01-01

285

Ex vivo Mechanical Loading of Tendon  

PubMed Central

Injuries to the tendon (e.g., wrist tendonitis, epicondyltis) due to overuse are common in sports activities and the workplace. Most are associated with repetitive, high force hand activities. The mechanisms of cellular and structural damage due to cyclical loading are not well known. The purpose of this video is to present a new system that can simultaneously load four tendons in tissue culture. The video describes the methods of sterile tissue harvest and how the tendons are loaded onto a clamping system that is subsequently immersed into media and maintained at 37°C. One clamp is fixed while the other one is moved with a linear actuator. Tendon tensile force is monitored with a load cell in series with the mobile clamp. The actuators are controlled with a LabView program. The four tendons can be repetitively loaded with different patterns of loading, repetition rate, rate of loading, and duration. Loading can continue for a few minutes to 48 hours. At the end of loading, the tendons are removed and the mid-substance extracted for biochemical analyses. This system allows for the investigation of the effects of loading patterns on gene expression and structural changes in tendon. Ultimately, mechanisms of injury due to overuse can be studies with the findings applied to treatment and prevention.

Asundi, Krishna; Rempel, David

2007-01-01

286

Ultrasonic evaluation of flood gate tendons.  

National Technical Information Service (NTIS)

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. Moisture may seep into the grout around the tendons and cause corro...

G. Thomas A. Brown

1997-01-01

287

Temperature anisotropy effect on the tearing mode  

NASA Astrophysics Data System (ADS)

Effects of the temperature anisotropy on the tearing mode in an ion-scale thick current sheet have been investigated using the two-dimensional full particle simulations Systematic survey has been performed fixing the ion-to-electron mass ratio to 25 and varying D and alpha j T j perp T j para D the initial current sheet half thickness normalized by the ion inertial length alpha j the temperature anisotropy for species j ion or electron T j perp and T j para the temperatures perpendicular and parallel to the initial magnetic field for the species j When the system size is set to Lx lambda max 12D lambda max the fastest growing mode of the tearing mode D 0 6 is the critical thickness above which no significant growth of the tearing mode is expected for alpha e 1 However alpha e 1 allows both the growth rate and the saturation level of the tearing to increase rapidly at the super-critical thickness range via the excitations of the higher wave modes When Lx 24D and alpha e 1 the saturation level of the tearing mode becomes much larger than the Lx 12D case by way of the coalescence stage of the magnetic islands of lambda max Presence of the ion anisotropy alpha i 1 also enhances the growth rate of the tearing mode but the influence of alpha i on the tearing is not as significant as that of alpha e

Haijima, K.; Tanaka, K. G.; Fujimoto, M.; Shinohara, I.

288

Analysis of meibum and tear lipids.  

PubMed

The meibum is a lipid-rich secretion that is the primary component of the external layer of the tear film. The meibomian glands produce the meibum, and meibomian gland dysfunction can lead to degradation of the tear film. Such dysfunction can result in ocular irritation, inflammation, and clinical disease. Understanding this relationship is critical to preventing ocular disease; therefore, a search of peer-reviewed literature focusing on the collection, quantification, and analysis of normal and abnormal meibum and tear lipids was conducted. Numerous collection and quantification techniques are described, including their advantages and disadvantages. Studies indicate that the meibum and tear lipids consist of a large array of polar and nonpolar lipids; individual lipids or their classes can be correlated to pathology. Significant amounts of lipids are deposited on contact lenses, depending on the nature of their polymer chemistry. These findings taken together indicate that normal meibum and tear lipids are essential for normal ocular health. Additional studies are required to provide a better understanding of the meibum and tear film biomolecules so that more effective treatments for blepharitis, dry eye disease, and tear film-related contact lens complications can be devised. PMID:23084145

Pucker, Andrew D; Nichols, Jason J

2012-07-25

289

Validity and reliability of the achilles tendon total rupture score.  

PubMed

The best treatment of acute Achilles tendon rupture remains debated. Patient-reported outcome measures have become cornerstones in treatment evaluations. The Achilles tendon total rupture score (ATRS) has been developed for this purpose but requires additional validation. The purpose of the present study was to validate a Danish translation of the ATRS. The ATRS was translated into Danish according to internationally adopted standards. Of 142 patients, 90 with previous rupture of the Achilles tendon participated in the validity study and 52 in the reliability study. The ATRS showed moderately strong correlations with the physical subscores of the Medical Outcomes Study 36-item Short-Form Health Survey (r = .70 to .75; p < .0001) and Victorian Institute of Sports Assessment-Achilles questionnaire (r = .71; p < .0001). Test-retest of the ATRS showed no significant difference in the mean (2.41; p = .07). The limits of agreement were ±18.53. A strong correlation was found between test and retest (intercorrelation coefficient .908); the standard error of measurement was 6.7, and the minimal detectable change was 18.5. The Danish version of the ATRS showed moderately strong criterion validity. For study and follow-up purposes, the ATRS seems reliable for comparisons of groups of patients. Its usability is limited for repeated assessment of individual patients. The development of analysis guidelines would be desirable. PMID:23965178

Ganestam, Ann; Barfod, Kristoffer; Klit, Jakob; Troelsen, Anders

2013-08-18

290

Percutaneous and minimally invasive techniques of Achilles tendon repair.  

PubMed

Despite the controversy regarding the best treatment for an acute Achilles tendon rupture, percutaneous and minimally invasive techniques seem to offer good results in terms of low risks of rerupture and complications with satisfactory clinical and functional outcomes. A comparison between a percutaneous surgical technique and a minimally invasive one has not been reported in the literature. We consecutively evaluated 12 patients who had a modified Ma and Griffith percutaneous Achilles tendon repair and 12 patients who had a minimally invasive technique. The same semifunctional rehabilitation protocol was used after surgery in both groups. At a minimum followup of 24 months (mean, 33 months; range, 24-42 months), we observed no reruptures or major complications in either group. Both groups had similarly high values for the American Orthopaedic Foot and Ankle Society score. The two techniques allowed equivalent time for return to work and sports. In the group of patients treated with the modified Ma and Griffith suture only, the mean loss of calf circumference in the injured leg was greater, compared with the contralateral leg. The two groups were isokinetically similar. In this study, the percutaneous and minimally invasive techniques of repair of the Achilles tendon yielded essentially identical clinical and functional outcomes. PMID:17290155

Ceccarelli, Francesco; Berti, Lisa; Giuriati, Laura; Romagnoli, Matteo; Giannini, Sandro

2007-05-01

291

Secondary tearing mode in the nonlinear evolution of magnetorotational instability  

NASA Astrophysics Data System (ADS)

Numerical investigation of the two-dimensional magnetic reconnection is given in the context of the nonlinear evolution of the Magneto-Rotational Instability (MRI). With a careful comparison to various theories using both one- and two-dimensional analysis, it is found that a new stabilizing effect of the centrifugal force on tearing instability must be present in the specific geometry of the MRI. Magnetic reconnection might play a key role to the formation of the nonaxisymmetric structures observed in MRI experiments. The results may also be useful for the estimate of the accretion rate in various astrophysical objects.

Tatsuno, T.; Dorland, W.

2008-09-01

292

Current-interchange tearing modes: Conversion of interchange-type modes to tearing modes  

Microsoft Academic Search

It is shown that, in addition to usual neoclassical tearing modes, another type of nonclassical tearing mode exists in tokamaks: viz., current-interchange tearing modes (CITMs). CITMs are directly driven by unstable pressure-driven electromagnetic or electrostatic modes of the interchange type (e.g., interchange\\/ballooning modes, drift waves, etc.) due to the current gradient in tokamaks. Interchange-type modes exchange not only thermal and

L. J. Zheng; M. Furukawa

2010-01-01

293

Fast Growth and Sheared Flow Generation in Nonlinear Development of Double Tearing Modes  

Microsoft Academic Search

The nonlinear development of double tearing modes (DTMs) mediated by parallel electron viscosity in a large aspect ratio torus is simulated. The emphasis is placed on the mechanisms for the fast growth and sheared flow generation in the development of the DTMs. Four nonlinear developing stages: the early growth, transition, fast growth and decay, are found. In comparison with the

J. Q. Dong; Y. X. Long; Z. Z. Mou; Z. X. Wang; J. Q. Li; Y. Kishimoto

294

Artificial tendons: biomechanical design properties for prosthetic lower limbs  

Microsoft Academic Search

This paper reports on the design of an artificial tendon intended for use in a powered, lower limb prosthesis. To specify performance requirements, the properties of mammalian weight bearing tendons are drawn from the literature and compared with a number of existing tendon models. Based on the data, a mathematical model of an energy storing tendon is proposed and used

Glenn K. Klute; Joseph M. Czerniecki; Blake Hannaford

2000-01-01

295

An assessment of alternate keyboards using finger motion, wrist motion and tendon travel  

Microsoft Academic Search

Objective. To assess the biomechanical impact of commercially available alternate keyboard designs.Design. A repeated measures study was conducted in a laboratory setting, with planned comparisons of Pitch, Roll and Yaw angles of the keyboards. Ten keyboard conditions were tested. Dependent measures included tendon travel, wrist deviations, and wrist and finger kinematics.Background. Various alternate keyboard designs have recently been introduced, which

Delia E. Treaster; Williams S. Marras

2000-01-01

296

Tear Strength of Elastomers under Threshold Conditions.  

National Technical Information Service (NTIS)

Measurements have been made of the tear strength of several elastomeric materials under threshold conditions, i.e., in the swollen state and at high temperatures when dissipative contributions to the work of fracture are minimized. The materials studied w...

A. K. Bhowmick A. N. Gent C. T. R. Pulford

1983-01-01

297

Natural history of anterior cruciate tears  

Microsoft Academic Search

An evaluation of 361 patients with documented anterior cru ciate tears was carried out with analysis of mechanisms, symp tomatology, physical findings, and limitations. At the time of injury, patients generally heard a loud pop and felt their knee \\

James A. Arnold; Tom P. Coker; Lynn M. Heaton; John P. Park; Walter Duke Harris

1979-01-01

298

Dopamine and its metabolites in human tears.  

PubMed

Dopamine is known to stimulate ion transport in the corneal epithelium. Since epithelium is in contact with tears, we searched for dopamine and its metabolites in tears. Twenty normal subjects participated in this study. Twenty microliters of tears were collected in capillary tubes after trigeminal stimulation and immediately analyzed using high-performance liquid chromatography with electrochemical detection. Dopamine and two of its metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), were identified and measured. The mean concentration of dopamine was 8.9 +/- 5.1 ng/ml; DOPAC, 2.2 +/- 1.6 ng/ml; and HVA, 0.55 +/- 0.4 ng/ml. These results permit us to suggest that dopamine is deaminated by monoamine oxidase, then methylated by catechol-O-methyltransferase and that catabolism occurs in the lacrimal gland and perhaps in corneal epithelium. Finally, part of the dopamine involved in ion transport may come from tears. PMID:8353435

Martin, X D; Brennan, M C

299

Reconstruction of quadriceps tendon with Achilles tendon allograft in older children with congenital dislocation of the knee  

Microsoft Academic Search

This is a case report of two children with congenital dislocation of the knee. They have been treated surgically with Z-lengthening of the quadriceps tendon and additional reconstruction of the quadriceps tendon with Achilles tendon allograft to fill in the remaining average 6 cm gap of the tendon. The patients were two girls, 6 and 9 years old. One of them had

Yetkin Söyüncü; Ercan M?hç?; Haluk Özcanl?; Merter Özenci; Feyyaz Aky?ld?z; A. Turan Ayd?n

2006-01-01

300

Cup arthroplasty for rotator cuff tear arthropathy.  

PubMed

Cup arthroplasty is a conservative bone-sparing option for resurfacing of the humeral head. Earlier reports have shown its effectiveness in appropriately selected patients with osteoarthritis, osteonecrosis, and severe rheumatoid arthritis. Patients with cuff tear arthropathy may also benefit from a modified cup arthroplasty technique. The purpose of this article is to describe the surgical technique involved in humeral cup arthroplasty in cuff tear arthropathy patients. We will review the indications, contraindications, complications, and postoperative rehabilitation. PMID:21358516

Mariscalco, Michael W; Patterson, Ryan W; Seitz, William H

2011-03-01

301

Collisionless and Collisional Tearing Mode in Gyrokinetics  

Microsoft Academic Search

We present numerical results of linear tearing mode simulations for collisionless and collisional regimes in a strong guide magnetic field limit using the AstroGK astrophysical gyrokinetics code. In the collisionless regime, the two-fluid effect, instead of the resistivity, mediates reconnection. Mirnov et al. and Fitzpatrick et al. have derived linear and nonlinear versions of reduced two-fluid models for the tearing

Ryusuke Numata; Tomoya Tatsuno; William Dorland; Barret Rogers

2009-01-01

302

Human Tears Reveal Insights into Corneal Neovascularization  

PubMed Central

Corneal neovascularization results from the encroachment of blood vessels from the surrounding conjunctiva onto the normally avascular cornea. The aim of this study is to identify factors in human tears that are involved in development and/or maintenance of corneal neovascularization in humans. This could allow development of diagnostic tools for monitoring corneal neovascularization and combination monoclonal antibody therapies for its treatment. In an observational case-control study we enrolled a total of 12 patients with corneal neovascularization and 10 healthy volunteers. Basal tears along with reflex tears from the inferior fornix, superior fornix and using a corneal bath were collected along with blood serum samples. From all patients, ocular surface photographs were taken. Concentrations of the pro-angiogenic cytokines interleukin (IL)-6, IL-8, Vascular Endothelial Growth Factor (VEGF), Monocyte Chemoattractant Protein 1 (MCP-1) and Fas Ligand (FasL) were determined in blood and tear samples using a flow cytometric multiplex assay. Our results show that the concentration of pro-angiogenic cytokines in human tears are significantly higher compared to their concentrations in serum, with highest levels found in basal tears. Interestingly, we could detect a significantly higher concentration of IL- 6, IL-8 and VEGF in localized corneal tears of patients with neovascularized corneas when compared to the control group. This is the first study of its kind demonstrating a significant difference of defined factors in tears from patients with neovascularized corneas as compared to healthy controls. These results provide the basis for future research using animal models to further substantiate the role of these cytokines in the establishment and maintenance of corneal neovascularization.

Wouters, Kristien; Rozema, Jos; Koppen, Carina; Lion, Eva; Cools, Nathalie; Berneman, Zwi; Tassignon, Marie-Jose

2012-01-01

303

Biological Augmentation of Rotator Cuff Tendon Repair  

PubMed Central

A histologically normal insertion site does not regenerate following rotator cuff tendon-to-bone repair, which is likely due to abnormal or insufficient gene expression and/or cell differentiation at the repair site. Techniques to manipulate the biologic events following tendon repair may improve healing. We used a sheep infraspinatus repair model to evaluate the effect of osteoinductive growth factors and BMP-12 on tendon-to-bone healing. Magnetic resonance imaging and histology showed increased formation of new bone and fibrocartilage at the healing tendon attachment site in the treated animals, and biomechanical testing showed improved load-to-failure. Other techniques with potential to augment repair site biology include use of platelets isolated from autologous blood to deliver growth factors to a tendon repair site. Modalities that improve local vascularity, such as pulsed ultrasound, have the potential to augment rotator cuff healing. Important information about the biology of tendon healing can also be gained from studies of substances that inhibit healing, such as nicotine and antiinflammatory medications. Future approaches may include the use of stem cells and transcription factors to induce formation of the native tendon-bone insertion site after rotator cuff repair surgery.

Kovacevic, David

2008-01-01

304

Patellar tendonitis and anterior knee pain.  

PubMed

Patellar tendonitis or "jumper's knee" is an important cause of anterior knee pain. The natural history, classification of the lesion, and treatment methods, however, remain controversial. This article presents a retrospective review of 40 patients (50 knees) with various stages of patellar tendonitis and examines the etiology, presentation, clinical picture, investigation, and results of conservative treatment. Twenty-nine men and 11 women ranging in age from 17-48 years comprised the study population. Ten patients had bilateral involvement. The overall evaluation of patients' treatment was 70% with normal or nearly normal results and 30% with abnormal or very abnormal results; most required surgical treatment in the form of arthroscopy, anterior compartment decompression, and patellar tendon exploration. Thirty-seven percent of the patients had a previous history of anterior knee pain (25% had Osgood-Schlatter disease and 12.5% had anterior knee pain). Patellar tendon involvement is appraised according to a new concept. Since patellar tendonitis is part of the wider picture of anterior knee pain, patellar tendonitis is classified as primary or secondary according to presentation, magnetic resonance imaging in general, and the pathology of the patellar tendon in particular. Treatment is planned accordingly. PMID:10323501

Duri, Z A; Aichroth, P M; Wilkins, R; Jones, J

1999-01-01

305

Diagnostic accuracy of ACL tears according to tear morphology.  

PubMed

This retrospective analysis of 182 consecutive patients who underwent anterior cruciate ligament (ACL) reconstruction aimed to assess the clinical examination under anaesthetic and the MRI diagnostic accuracy of arthroscopically-proven, complete ACL ruptures, depending on the morphology of the torn ligament. Patients were then assigned to Group 1 (ACL not reattached) or Group 2 (ACL re-attached abnormally). Of 104 patients (57.1%) in Group 2, 94 (51.7%) had an abnormal re-attachment of the torn ACL to the posterior cruciate ligament (PCL). There was no significant difference between the groups on MRI reporting of a complete ACL tear (p = 0.123) and pivot shift test. On Lachman testing, more patients in Group 1 had an increased laxity compared with Group 2 (p = 0.014); similarly, more patients in Group 1 had an absent endpoint compared with Group 2 (p = 0.008). An ACL-deficient knee with an abnormal re-attachment of the torn ligament appears to be more difficult to diagnose than if there has been no re-attachment. PMID:23547520

Dhillon, Ajit K; Al-Dadah, Oday; Servant, Christopher T J

2013-02-01

306

Tensile properties of the in vivo human gastrocnemius tendon  

Microsoft Academic Search

In the present experiment we obtained the tensile properties of the human gastrocnemius tendon, a high-stressed tendon suitable for spring-like action during locomotion. Measurements were taken in vivo in six men. The gastrocnemius tendon elongation during tendon loading?unloading induced by muscle contraction?relaxation was measured using real-time ultrasonography. Tendon forces were calculated from the moment generated during isometric plantarflexion contraction, using

Constantinos N Maganaris; John P Paul

2002-01-01

307

Three-dimensional study of pectoralis major muscle and tendon architecture.  

PubMed

A thorough understanding of the normal structural anatomy of the pectoralis major (PM) is of paramount importance in the planning of PM tendon transfers or repairs following traumatic PM tears. However, there is little consensus regarding the complex musculotendinous architecture of the PM in the anatomic or surgical literature. The purpose of this study is to model and quantify the three-dimensional architecture of the pectoralis muscle and tendon. Eleven formalin embalmed cadaveric specimens were examined: five (2M/3F) were serially dissected, digitized, and modeled in 3D using Autodesk Maya; six (4M/2F) were dissected and photographed. The PM tendon consisted of longer anterior and shorter posterior layers that were continuous inferiorly. The muscle belly consisted of an architecturally uniform clavicular head (CH) and a segmented sternal head (SH) with 6-7 segments. The most inferior SH segment in all specimens was found to fold anteriorly forming a trough that cradled the inferior aspect of the adjacent superior segment. No twisting of either the PM muscle or tendon was noted. Within the CH, the fiber bundle lengths (FBL) were found to increase from superior to inferior, whereas the mean FBLs of SH were greatest in segments 3-5 found centrally. The mean lateral pennation angle was greater in the CH (29.4 +/- 6.9 degrees ) than in the SH (20.6 +/- 2.7 degrees ). The application of these findings could form the basis of future studies to optimize surgical planning and functional recovery of repair/reconstruction procedures. PMID:19291757

Fung, Lillia; Wong, Brian; Ravichandiran, Kajeandra; Agur, Anne; Rindlisbacher, Tim; Elmaraghy, Amr

2009-05-01

308

Tendon and ligament regeneration and repair: Clinical relevance and developmental paradigm.  

PubMed

As dense connective tissues connecting bone to muscle and bone to bone, respectively, tendon and ligament (T/L) arise from the somitic mesoderm, originating in a recently discovered somitic compartment, the syndetome. Inductive signals from the adjacent sclerotome and myotome upregulate expression of Scleraxis, a key transcription factor for tenogenic and ligamentogenic differentiation. Understanding T/L development is critical to establishing a knowledge base for improving the healing and repair of T/L injuries, a high-burden disease due to the intrinsically poor natural healing response. Current treatment of the three most common tendon injuries-tearing of the rotator cuff of the shoulder, flexor tendon of the hand, and Achilles tendon-include mostly surgical repair and/or conservative approaches, including biophysical modalities such as rehabilitation and cryotherapy. Unfortunately, the fibrovascular scar formed during healing possesses inferior mechanical and biochemical properties, resulting in compromised tissue functionality. Regenerative approaches have sought to augment the injured tissue with cells, scaffolds, bioactive agents, and mechanical stimulation to improve the natural healing response. The key challenges in restoring full T/L function following injury include optimal combination of these biological agents as well as their delivery to the injury site. A greater understanding of the molecular mechanisms involved in T/L development and natural healing, coupled with the capability of producing complex biomaterials to deliver multiple biofactors with high spatiotemporal resolution and specificity, should lead to regenerative procedures that more closely recapitulate T/L morphogenesis, thereby offering future patients the prospect of T/L regeneration, as opposed to simple tissue repair. Text. Birth Defects Research (Part C) 99:203-222, 2013. © 2013 Wiley Periodicals, Inc. PMID:24078497

Yang, Guang; Rothrauff, Benjamin B; Tuan, Rocky S

2013-09-01

309

Combined anterior tibial tendon rupture and posterior tibial tendon dysfunction in advanced flatfoot.  

PubMed

The combination of spontaneous anterior tibial tendon rupture and posterior tibial tendon dysfunction has rarely been reported in the literature. This is a case report of a 78-year-old patient presenting with a history of longstanding, progressive flatfoot deformity, clinically grade III posterior tibial tendon dysfunction, and dropfoot gait. Radiographic films revealed severe flatfoot, and the clinical examination was consistent with a complete rupture of the anterior tibial tendon and severe posterior tibial tendon degeneration as well as rupture of the spring and deltoid ligaments. Treatment by triple arthrodesis and repair of the anterior tibial tendon affected pain relief and clinical as well as radiographic correction at the 4-month postoperative assessment. PMID:17145469

Frigg, Arno Martin; Valderrabano, Victor; Kundert, Hans-Peter; Hintermann, Beat

310

An insight on multiscale tendon modeling in muscle–tendon integrated behavior  

Microsoft Academic Search

This paper aims to highlight the need for a refined tendon model to reproduce the main mechanical features of the integrated\\u000a muscle–tendon unit (MTU). Elastic nonlinearities of the tendon, both at the nano and microscale, are modeled by a multiscale\\u000a approach, accounting for the hierarchical arrangement (from molecules up to the fibers) of the collagen structures within\\u000a the tissue. This

Franco Maceri; Michele Marino; Giuseppe Vairo

311

Pathology of the posterior tibial tendon in posterior tibial tendon insufficiency.  

PubMed

Gross and histologic examinations of 15 normal cadaver and 15 surgical posterior tibial tendons from patients with posterior tibial tendon insufficiency were performed. All surgical specimens were abnormal with enlargement distal to the medial malleolus and a dull white appearance. At histologic examination, 12 of 15 cadaver tendons displayed normal tendon structure characterized by linear orientation of collagen bundles, normal fibroblast cellularity, low vascular density, and insertional chondroid metaplasia. The surgical specimens displayed a degenerative tendinosis characterized by increased mucin content, fibroblast hypercellularity, chondroid metaplasia, and neovascularization. This resulted in marked disruption of the linear orientation of the collagen bundles. PMID:9728698

Mosier, S M; Lucas, D R; Pomeroy, G; Manoli, A

1998-08-01

312

Intrasynovial Tendon Graft for Chronic Flexor Tendon Laceration of the Finger: A Case Report  

PubMed Central

We present the case of a patient with flexor digitorum profundus tendon laceration at the A2 pulley level caused by an injury to the base of the right ring finger by a knife. The patient was treated by flexor tendon reconstruction from the palm to the fingertip by using the left second toe flexor tendon as a graft, which improved the active range of motion. Further improvement was achieved by subsequent tenolysis, which eventually restored nearly normal function. Our experience with this case indicates that the intrasynovial tendon is a reasonable graft source for the synovial space in fingers and may enable restoration of excellent postoperative function.

Sasaki, Jun; Itsubo, Toshiro; Nakamura, Koichi; Hayashi, Masanori; Uchiyama, Shigeharu; Kato, Hiroyuki

2013-01-01

313

Clinical measurement of patellar tendon: accuracy and relationship to surgical tendon dimensions.  

PubMed

Patellar tendon width and length are commonly used for preoperative planning for anterior cruciate ligament reconstruction (ACLR). In the study reported here, we assessed the accuracy of preoperative measurements made by palpation through the skin, and correlated these measurements with the actual dimensions of the tendons at surgery. Before making incisions in 53 patients undergoing ACLR with patellar tendon autograft, we measured patellar tendon length with the knee in full extension and in 90° of flexion, and tendon width with the knee in 90° of flexion. The tendon was then exposed, and its width was measured with the knee in 90° of flexion. The length of the central third of the tendon was measured after the graft was prepared. Mean patellar tendon length and width with the knee in 90° of flexion were 39 mm and 32 mm, respectively. No clinical difference was found between the estimated pre-incision and surgical widths. However, the estimated pre-incision length with the knee in full extension and in 90° of flexion was significantly shorter than the surgical length. Skin measurements can be used to accurately determine patellar tendon width before surgery, but measurements of length are not as reliable. PMID:24078943

Zooker, Chad; Pandarinath, Rajeev; Kraeutler, Matthew J; Ciccotti, Michael G; Cohen, Steven B; Deluca, Peter F

2013-07-01

314

[Flexor and extensor tendon injuries in children (primary and secondary repair)].  

PubMed

Primary or secondary flexor tendon repair after laceration in children do not have any technical specificity in comparison with adults. However, tendon ruptures may occur more frequently in case of light postoperative immobilization, especially in young children as little cooperation can be expected in the postoperative period. A closed above elbow cast should therefore be applied for onemonth. Early mobilization program has no significant effect on the final result in young children. However, these observations must be relativized in teenagers who should be rehabilitated such as adults. For extensor tendon injuries, dynamic splintage was found to be unnecessary in children. In cases with total transection in zones I, II or III, it is necessary, especially in children younger than 5 years, to transfix the IP joint in extension with a smooth Kirschner wire during postoperative immobilization period. PMID:23628559

Dinh, A

2013-04-09

315

Biomicroscopy of the tear film: the tear film of the pekingese dog  

Microsoft Academic Search

Polarised light biomicroscopy was used to examine the normal pre-corneal tear film in 21 eyes of 12 pekingese dogs. The purpose of the study was to examine the influence of excessive exophthalmos on the pre-corneal tear film in the dog. The majority of the animals were found to have high levels of ocular surface contamination by particulate material and plaques

SD Carrington; PG Bedford; JP Guillon; EG Woodward

1989-01-01

316

Fiber Bragg grating displacement sensor for movement measurement of tendons and ligaments  

NASA Astrophysics Data System (ADS)

Biomechanical studies often involve measurements of the strains developed in tendons or ligaments in posture or locomotion. Fiber-optic sensors present an attractive option for the measurement of strains in tendons and ligaments because of their low cost, ease of implementation, and increased accuracy compared with other implantable transducers. A new displacement sensor based on a fiber Bragg grating and shape memory alloy technology is proposed for the monitoring of tendon and ligament strains in different postures and in locomotion. After sensor calibration in the laboratory, a comparison of the fiber sensors and traditional camera displacement sensors was carried out to evaluate the performance of the fiber sensor during the application of tension to the Achilles tendon. Additional experiments were performed in cadaver knees to assess the suitability of these fiber sensors to measure ligament deformation in a variety of simulated postures. The results demonstrate that the proposed fiber Bragg grating sensor is a highly accurate, easily implantable, and minimally invasive method of measuring tendon and ligament displacement.

Ren, Liang; Song, Gangbing; Conditt, Michael; Noble, Philip C.; Li, Hongnan

2007-10-01

317

Tendon Fibroplasia Induction by Exogenous Electrical Fields.  

National Technical Information Service (NTIS)

A parametric study is being undertaken of the effects of extra low frequency (ELF) conductive electric fields on chicken tendon explant fibroplasia, collagen synthesis and oriented migration. Independent variables are: pulse repetition rate, pulse duratio...

S. F. Cleary L. M. Liu R. Diegelmann

1986-01-01

318

Temperture anisotropy effect on the tearing mode  

NASA Astrophysics Data System (ADS)

Previous study of the Plasma temperature anisotropy in the current sheet have shown that ?j > 1 (?j = Tj,perp/Tj,para , j = ion or electron) significantly enhances the growth rate of tearing instability (TI), and the maximum growth wave length shift for shorter by the linear theory [Chen & Palmadesso, Phys. Fluds 1984; Ambrosiano, Geophys. Res. 1986]. Recent result of the two-dimensional (2- D) particle-in cell simulation with M=100 (M: ion to electron mass ratio) have demonstrated that presence of ?e efficiently boost up the reconnection flux in the linear phase [Karimabadi et al. 2004]. In contrast, Tanaka [et, al, 2004] have revealed a critical thickness D&cr above which no significant reconnection takes place by 2-D PIC isotopic simulation. Those results lead to some questions. 1. Does ?j really enable to take place reconnection with D > Dcr? (D: the initial current sheet thickness) 2. Is ?&&j still effective in the nonlinear phase as well as linear phase ? 3. Does ?j finally bring the sufficient development of the reconnection ? In order to clarify those questions, we have systematically investigated the effects of ?i and ?e on TI using 2-D PIC simulation varying M and D. The results are as follows 1. While ?e boosts up the growth rate of the shorter wavelengths in the early time, it dose not bring a sufficient development of the reconnection at D > Dcr in the nonlinear phase for M >= 100 [Haijima et al. 2006]. 2. In contrast, ?i boosts up the growth rate develop and contributes to sufficient development of the reconnection at D > Dcr even for M = 100. 3. A characteristic fastest growing wavelength is found in the early time for each ?j In this presentation, we will make a comparison between the effect of ?i and ?e on TI

Haijima, K.; Tanaka, K.; Fujimoto, M.; Shinohara, I.

2006-12-01

319

A new hot-tearing criterion  

NASA Astrophysics Data System (ADS)

A new criterion for the appearance of hot tears in metallic alloys is proposed. Based upon a mass balance performed over the liquid and solid phases, it accounts for the tensile deformation of the solid skeleton perpendicular to the growing dendrites and for the induced interdendritic liquid feeding. This model introduces a critical deformation rate (dot \\varepsilon _{p,max } ) beyond which cavitation, i.e., nucleation of a first void, occurs. As should be expected, this critical value is an increasing function of the thermal gradient and permeability and a decreasing function of the viscosity. The shrinkage contribution, which is also included in the model, is shown to be of the same order of magnitude as that associated with the tensile deformation of the solid skeleton. A hot-cracking sensitivity (HCS) index is then defined as dot \\varepsilon _{_{p,max } }^{ - 1} . When applied to a variable-concentration aluminum-copper alloy, this HCS criterion can reproduce the typical “? curves” previously deduced by Clyne and Davies on a phenomenological basis. The calculated values are in fairly good agreement with those obtained experimentally by Spittle and Cushway for a non-grain-refined alloy. A comparison of this criterion to hot cracks observed in ring-mold solidification tests indicates cavitation depression of a few kilo Pascal and tensile stresses in the coherent mushy zone of a few mega Pascal. These values are discussed in terms of those obtained by other means (coherency measurement, microporosity observation, and simulation). Even though this HCS criterion is based only upon the appearance of a first void and not on its propagation, it sets up for the first time a physically sound basis for the study of hot-crack formation.

Rappaz, M.; Drezet, J.-M.; Gremaud, M.

1999-02-01

320

Biological Augmentation of Rotator Cuff Tendon Repair  

Microsoft Academic Search

A histologically normal insertion site does not regenerate following rotator cuff tendon-to-bone repair, which is likely due\\u000a to abnormal or insufficient gene expression and\\/or cell differentiation at the repair site. Techniques to manipulate the biologic\\u000a events following tendon repair may improve healing. We used a sheep infraspinatus repair model to evaluate the effect of osteoinductive\\u000a growth factors and BMP-12 on

David Kovacevic; Scott A. Rodeo

2008-01-01

321

Three rare causes of extensor tendon rupture.  

PubMed

Three unusual cases of rupture of finger extensor tendons by attrition are reported. In one instance it was associated with long-standing nonunion of a scaphoid fracture, with a posttraumatic dorsal subluxation of the lower end of the ulna in another, and with a Madelung's deformity in the third. Extensor tendon rupture has not been previously recorded in the English-language literature after the first two conditions. PMID:2584656

Harvey, F J; Harvey, P M

1989-11-01

322

Mechanical properties of human patellar tendon at the hierarchical levels of tendon and fibril.  

PubMed

Tendons are strong hierarchical structures, but how tensile forces are transmitted between different levels remains incompletely understood. Collagen fibrils are thought to be primary determinants of whole tendon properties, and therefore we hypothesized that the whole human patellar tendon and its distinct collagen fibrils would display similar mechanical properties. Human patellar tendons (n = 5) were mechanically tested in vivo by ultrasonography. Biopsies were obtained from each tendon, and individual collagen fibrils were dissected and tested mechanically by atomic force microscopy. The Young's modulus was 2.0 ± 0.5 GPa, and the toe region reached 3.3 ± 1.9% strain in whole patellar tendons. Based on dry cross-sectional area, the Young's modulus of isolated collagen fibrils was 2.8 ± 0.3 GPa, and the toe region reached 0.86 ± 0.08% strain. The measured fibril modulus was insufficient to account for the modulus of the tendon in vivo when fibril content in the tendon was accounted for. Thus, our original hypothesis was not supported, although the in vitro fibril modulus corresponded well with reported in vitro tendon values. This correspondence together with the fibril modulus not being greater than that of tendon supports that fibrillar rather than interfibrillar properties govern the subfailure tendon response, making the fibrillar level a meaningful target of intervention. The lower modulus found in vitro suggests a possible adverse effect of removing the tissue from its natural environment. In addition to the primary work comparing the two hierarchical levels, we also verified the existence of viscoelastic behavior in isolated human collagen fibrils. PMID:22114175

Svensson, René B; Hansen, Philip; Hassenkam, Tue; Haraldsson, Bjarki T; Aagaard, Per; Kovanen, Vuokko; Krogsgaard, Michael; Kjaer, Michael; Magnusson, S Peter

2011-11-23

323

Achilles tendon suture deteriorates tendon capillary blood flow with sustained tissue oxygen saturation - an animal study  

PubMed Central

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.

Kraemer, Robert; Lorenzen, Johan; Rotter, Robert; Vogt, Peter M; Knobloch, Karsten

2009-01-01

324

Evolution of the Achilles tendon: The athlete's Achilles heel?  

PubMed

The Achilles tendon is believed to have first developed two million years ago enabling humans to run twice as fast. However if the Achilles tendon is so important in terms of evolution, then why is this tendon so prone to injury - especially for those more active like athletes. The Achilles tendon had an integral role in evolving apes from a herbivorous diet to early humans who started hunting for food over longer distances, resulting in bipedal locomotion. Evolutionary advantages of the Achilles tendon includes it being the strongest tendon in the body, having an energy-saving mechanism for fast locomotion, allows humans to jump and run, and additionally is a spring and shock absorber during gait. Considering these benefits it is therefore not surprising that studies have shown athletes have thicker Achilles tendons than subjects who are less active. However, contradictory to these findings that show the importance of the Achilles tendon for athletes, it is well known that obtaining an Achilles tendon injury for an athlete can be career-altering. A disadvantage of the Achilles tendon is that the aetiology of its pathology is complicated. Achilles tendon ruptures are believed to be caused by overloading the tensed tendon, like during sports. However studies have also shown athlete Achilles tendon ruptures to have degenerative changes in the tendon. Other flaws of the Achilles tendon are its non-uniform vascularity and incomplete repair system which may suggest the Achilles tendon is on the edge of evolution. Research has shown that there is a genetic influence on the predisposition a person has towards Achilles tendon injuries. So if this tendon is here to stay in our anatomy, and it probably is due to the slow rate of evolution in humans, research in genetic modification could be used to decrease athletes' predisposition to Achilles tendinopathy. PMID:21900004

Malvankar, S; Khan, W S

2011-09-06

325

Collisionless and Collisional Tearing Mode in Gyrokinetics  

NASA Astrophysics Data System (ADS)

We present numerical results of linear tearing mode simulations for collisionless and collisional regimes in a strong guide magnetic field limit using the AstroGK astrophysical gyrokinetics code. In the collisionless regime, the two-fluid effect, instead of the resistivity, mediates reconnection. Mirnov et al. and Fitzpatrick et al. have derived linear and nonlinear versions of reduced two-fluid models for the tearing mode in the presence of the guide field^1,2. We compare numerically obtained tearing mode growth rate with those theories. For the collisional regime, we compare gyrokinetic simulation results with the classical tearing mode theory by Furth, Kileen, and Rosenbluth, and with a fluid simulation. This benchmarks recently implemented resistivity term in the code. AstroGK can smoothly connect those two regimes. We also discuss the scaling of the growth rate against the collisionality in the intermediate regime, and how the kinetic effects play roles in the tearing mode. 1. V. V. Mirnov, C. C. Hegna, and S. C. Prager, Phys. Plasmas 11, 4468, (2004). 2. R. Fitzpatrick and F. Porcelli, Phys. Plasmas 11, 4713 (2004).

Numata, Ryusuke; Tatsuno, Tomoya; Dorland, William; Rogers, Barret

2009-05-01

326

[Functional tear production indices in thyroid eye disease].  

PubMed

Analysis of functional tear production indices in patients with Grave's disease and thyroid eye disease confirmed lacrimal gland involvement in inflammatory autoimmune process. Close direct correlation was found between tear production and main disease characteristics - severity and activity. PMID:23879029

Safonova, T N; Likhvantseva, V G; Gontiurova, O A; Rudenko, E I; Vygodin, V A

327

Long-term outcome and structural integrity following open repair of massive rotator cuff tears  

PubMed Central

Background: Surgical repair of massive rotator cuff tears is associated with less favorable clinical results and a higher retear rate than repair of smaller tears, which is attributed to irreversible degenerative changes of the musculotendinous unit. Materials and Methods: During the study period, 25 consecutive patients with a massive rotator cuff tear were enrolled in the study and the tears were repaired with an open suture anchor repair technique. Preoperative and postoperative clinical assessments were performed with the Constant score, the simple shoulder test (SST) and a pain visual analog scale (VAS). At the final follow-up, rotator cuff strength measurement was evaluated and assessment of tendon integrity, fatty degeneration and muscle atrophy was done using a standardized magnetic resonance imaging protocol. Results: The mean follow-up period was 70 months. The mean constant score improved significantly from 42.3 to 73.1 points at the final follow-up. Both the SST and the pain VAS improved significantly from 5.3 to 10.2 points and from 6.3 to 2.1, respectively. The overall retear rate was 44% after 6 years. Patients with an intact repair had better shoulder scores and rotator cuff strength than those with a failed repair, and also the retear group showed a significant clinical improvement (each P<0.05). Rotator cuff strength in all testing positions was significantly reduced for the operated compared to the contralateral shoulder. Muscle atrophy and fatty infiltration of the rotator cuff muscles did not recover in intact repairs, whereas both parameters progressed in retorn cuffs. Conclusions: Open repair of massive rotator tears achieved high patient satisfaction and a good clinical outcome at the long-term follow-up despite a high retear rate. Also, shoulders with retorn cuffs were significantly improved by the procedure. Muscle atrophy and fatty muscle degeneration could not be reversed after repair and rotator cuff strength still did not equal that of the contralateral shoulder after 6 years. Level of evidence: Level IV

Bartl, Christoph; Kouloumentas, Pannos; Holzapfel, Konstantin; Eichhorn, Stefan; Wortler, Klaus; Imhoff, Andreas; Salzmann, Gian M

2012-01-01

328

Rotator cuff tear measurement by arthropneumotomography  

SciTech Connect

Five years of experience with a method of shoulder arthrography using upright tomography in cases of suspected or known rotator cuff tears has demonstrated its effectiveness. The value of the procedure lies in its ability to demonstrate the size of the cuff tear and the thickness of the remaining cuff tissue. This information provides the surgeon with a preoperative estimate of the difficulty of the repair and the prognosis for a good functional recovery. In 33 cases, there was good correlation between the upright thin-section tomogram findings and the surgical results. The tomograms provided better information about the size of the tear and the quality of the remaining cuff than did plain arthrograms.

Kilcoyne, R.F.; Matsen, F.A. III

1983-02-01

329

Tear film dynamics with evaporation and osmolarity  

NASA Astrophysics Data System (ADS)

We consider a model problem for the evaporation and breakup up of tear film. The model includes the effects of surface tension, Marangoni stresses, insoluble surfactant transport, evaporation, osmolarity transport, osmosis and wetting of corneal surface. Evaporation is made dependent on surface concentration in order to mimic the lipid layer of the tear film when there is a single fluid layer in the model. In many cases for a single layer, the Marangoni effect seems to eliminate a localized area of increased evaporation due to reduced surfactant concentration. In this model the osmolarity in the tear film increases because of average evaporation rate rather than by a locally increased evaporation rate. If time permits, the effect of having a second fluid layer, representing the lipid layer, will be explored as well.

Siddique, Javed; Braun, Richard

2011-11-01

330

Arthroscopic repairs of triangular fibrocartilage complex tears.  

PubMed

Technical advancements in arthroscopic wrist procedures have improved our knowledge of normal and abnormal intraarticular wrist function. Triangular fibrocartilage complex (TFCC) tears from trauma injuries are a common source of ulnar-sided wrist pain. Fortunately, the TFCC is a structure that can be evaluated and treated arthroscopically with results that are comparable to open surgical procedures. Successful arthroscopic repairs of TFCC tears depend on a coordinated team effort between perioperative nurses, orthopedic surgeons, nurse practitioners, and occupational hand therapists, as well as cooperation from patients and family members. This article reviews the anatomy and physiology of the TFCC, the biomechanics of the wrist and mechanisms of injury, and arthroscopic repairs of TFCC tears. PMID:9220068

Baehser-Griffith, P; Bednar, J M; Osterman, A L; Culp, R

1997-07-01

331

Slab tears and intermediate-depth seismicity  

NASA Astrophysics Data System (ADS)

Active tectonic regions where plate boundaries transition from subduction to strike slip can take several forms, such as triple junctions, acute, and obtuse corners. Well-documented slab tears that are associated with high rates of intermediate-depth seismicity are considered here: Gibraltar arc, the southern and northern ends of the Lesser Antilles arc, and the northern end of Tonga trench. Seismicity at each of these locations occurs, at times, in the form of swarms or clusters, and various authors have proposed that each marks an active locus of tear propagation. The swarms and clusters start at the top of the slab below the asthenospheric wedge and extend 30-60 km vertically downward within the slab. We propose that these swarms and clusters are generated by fluid-related embrittlement of mantle rocks. Focal mechanisms of these swarms generally fit the shear motion that is thought to be associated with the tearing process.

Meighan, Hallie E.; Brink, Uri; Pulliam, Jay

2013-08-01

332

Arthroscopic Percutaneous Repair of Anterosuperior Rotator Cuff Tear Including Biceps Long Head: A 2-Year Follow-up  

PubMed Central

Background To report the results of an arthroscopic percutaneous repair technique for partial-thickness tears of the anterosuperior cuff combined with a biceps lesion. Methods The inclusion criteria were evidence of the upper subscapularis tendon tear and an articular side partial-thickness tear of the supraspinatus tendon, degeneration of the biceps long head or degenerative superior labrum anterior-posterior, above lesions treated by arthroscopic percutaneous repair, and follow-up duration > 24 months after the operation. American Shoulder and Elbow Surgeons (ASES) score, constant score, the pain level on a visual analogue scale, ranges of motion and strength were assessed. Results The mean (± standard deviation) age of the 20 enrolled patients was 56.0 ± 7.7 years. The forward flexion strength increased from 26.3 ± 6.7 Nm preoperatively to 38.9 ± 5.1 Nm at final follow-up. External and internal rotation strength was also significantly increased (14.2 ± 1.7 to 19.1 ± 3.03 Nm, 12.3 ± 3.2 to 18.1 ± 2.8 Nm, respectively). Significant improvement was observed in ASES and constant scores at 3 months, 1 year and the time of final follow-up when compared with preoperative scores (p < 0.001). The mean subjective shoulder value was 86% (range, 78% to 97%). Conclusions The implementation of complete rotator cuff repair with concomitant tenodesis of the biceps long head using arthroscopic percutaneous repair achieved full recovery of normal rotator cuff function, maximum therapeutic efficacy, and patient satisfaction.

Kim, Do-Young; Lee, Sang-Soo; Seo, Eun-Min; Hwang, Jung-Taek; Kwon, Sun-Chang; Lee, Jae-Won

2012-01-01

333

Quantitative Analysis of Tear Film Fluorescence and Discomfort During Tear Film Instability and Thinning  

PubMed Central

Purpose. The purpose of this study was to test the association between tear film fluorescence changes during tear break-up (TBU) or thinning and the concurrent ocular sensory response. Methods. Sixteen subjects kept one eye open as long as possible (MBI), indicated their discomfort level continuously, and rated ocular sensations of irritation, stinging, burning, pricking, and cooling using visual analog scales (VAS). Fluorescence of the tear film was quantified by a pixel-based analysis of the median pixel intensity (PI), TBU, and percentage of dark pixels (DarkPix) over time. A cutoff of 5% TBU was used to divide subjects into either break-up (BU) or minimal break-up (BUmin) groups. Results. Tear film fluorescence decreased (median PI) and the percentage of TBU and DarkPix increased in all trials, with the rate significantly greater in the BU than the BUmin group (Mann-Whitney U test, P < 0.05). The rate of increasing discomfort during trials was highly correlated with the rate of decrease in median PI and developing TBU (Spearman's, r ? 0.70). Significant correlations were found between corneal fluorescence, MBI, and sensory measures. Conclusions. Concentration quenching of fluorescein dye with tear film thinning best explains decreasing tear film fluorescence during trials. This was highly correlated with increasing ocular discomfort, suggesting that both tear film thinning and TBU stimulate underlying corneal nerves, although TBU produced more rapid stimulation. Slow increases in tear film hyperosmolarity may cause the gradual increase in discomfort during slow tear film thinning, whereas the sharp increases in discomfort during TBU suggest a more complex stimulus.

Begley, Carolyn; Simpson, Trefford; Liu, Haixia; Salvo, Eliza; Wu, Ziwei; Bradley, Arthur; Situ, Ping

2013-01-01

334

Crimp morphology in relaxed and stretched rat Achilles tendon  

PubMed Central

Fibrous extracellular matrix of tendon is considered to be an inextensible anatomical structure consisting of type I collagen fibrils arranged in parallel bundles. Under polarized light microscopy the collagen fibre bundles appear crimped with alternating dark and light transverse bands. This study describes the ultrastructure of the collagen fibrils in crimps of both relaxed and in vivo stretched rat Achilles tendon. Under polarized light microscopy crimps of relaxed Achilles tendons appear as isosceles or scalene triangles of different size. Tendon crimps observed via SEM and TEM show the single collagen fibrils that suddenly change their direction containing knots. The fibrils appear partially squeezed in the knots, bent on the same plane like bayonets, or twisted and bent. Moreover some of them lose their D-period, revealing their microfibrillar component. These particular aspects of collagen fibrils inside each tendon crimp have been termed ‘fibrillar crimps’ and may fulfil the same functional role. When tendon is physiologically stretched in vivo the tendon crimps decrease in number (46.7%) (P < 0.01) and appear more flattened with an increase in the crimp top angle (165° in stretched tendons vs. 148° in relaxed tendons, P < 0.005). Under SEM and TEM, the ‘fibrillar crimps’ are still present, never losing their structural identity in straightened collagen fibril bundles of stretched tendons even where tendon crimps are not detectable. These data suggest that the ‘fibrillar crimp’ may be the true structural component of the tendon crimp acting as a shock absorber during physiological stretching of Achilles tendon.

Franchi, Marco; Fini, Milena; Quaranta, Marilisa; De Pasquale, Viviana; Raspanti, Mario; Giavaresi, Gianluca; Ottani, Vittoria; Ruggeri, Alessandro

2007-01-01

335

Axial speed of sound is related to tendon's nonlinear elasticity.  

PubMed

Axial speed of sound (SOS) measurements have been successfully applied to noninvasively evaluate tendon load, while preliminary studies showed that this technique also has a potential clinical interest in the follow up of tendon injuries. The ultrasound propagation theory predicts that the SOS is determined by the effective stiffness, mass density and Poisson's ratio of the propagating medium. Tendon stiffness characterizes the tissue's mechanical quality, but it is often measured in quasi-static condition and for entire tendon segments, so it might not be the same as the effective stiffness which determines the SOS. The objectives of the present study were to investigate the relationship between axial SOS and tendon's nonlinear elasticity, measured in standard laboratory conditions, and to evaluate if tendon's mass density and cross-sectional area (CSA) affect the SOS level. Axial SOS was measured during in vitro cycling of 9 equine superficial digital tendons. Each tendon's stiffness was characterized with a tangent modulus (the continuous derivative of the true stress/true strain curve) and an elastic modulus (the slope of this curve's linear region). Tendon's SOS was found to linearly vary with the square root of the tangent modulus during loading; tendon's SOS level was found correlated to the elastic modulus's square root and inversely correlated to the tendon's CSA, but it was not affected by tendon's mass density. These results confirm that tendon's tangent and elastic moduli, measured in laboratory conditions, are related to axial SOS and they represent one of its primary determinants. PMID:22078274

Vergari, Claudio; Ravary-Plumioën, Bérangère; Evrard, Delphine; Laugier, Pascal; Mitton, David; Pourcelot, Philippe; Crevier-Denoix, Nathalie

2011-11-10

336

Indications for repair of full-thickness rotator cuff tears.  

PubMed

Rotator cuff repair surgery for full-thickness tears is common and accepted in orthopaedics today. Given that a significant number of people have asymptomatic rotator cuff tears, the indications for surgery are, however, somewhat unclear. Multiple factors such as duration of symptoms, acuity and size of the tear, patient age, and others require consideration and can influence the decision to perform surgery. This article reviews these variables and the indications for surgery to repair full-thickness rotator cuff tears. PMID:17337723

Wolf, Brian R; Dunn, Warren R; Wright, Rick W

2007-03-02

337

Superior labrum anterior-to-posterior tear.  

PubMed

The patient was a 25-year-old male college student with a chief complaint of right shoulder pain. The patient was initially diagnosed with bicipital tendinitis by his physician and had been treated for 4 weeks by a physical therapist. However, his symptoms did not improve and he was unable to return to his preinjury activity levels, so he sought the services of another physical therapist for a second opinion. Due to concern for a labrum tear, the physical therapist referred the patient to an orthopaedic surgeon. Magnetic resonance arthrography revealed findings consistent with a superior labrum anterior-to-posterior tear. PMID:23202247

Sum, Jonathan C; Omid, Reza

2012-11-30

338

Evaluation of medial meniscus tears and meniscal stability: weight-bearing MRI vs arthroscopy.  

PubMed

To assess the role of dedicated low-field standard and weight-bearing MRI in the evaluation of stable or unstable tears of medial meniscus in comparison with arthroscopy. Our series included 1750 knee MRI scans performed with a high-field MRI scanner from July 2010 to August 2011. We retrospectively reviewed and analyzed 20 MRI exams of normal knee and 57 MRI exams of knee with clinical evidence of tears of the medial meniscus. In the same session, after conventional 1.5T and "dedicated" 0.25T supine MRI exam, the patients underwent weight-bearing examination with the same dedicated MRI unit. In all cases sagittal and coronal PD-W were used. All patients underwent arthroscopy 18-25 days after the weight-bearing MRI. In the first group, no statistically significant anatomical modifications of shape, intensity and position of the medial meniscus between standard 1.5T, dedicated supine and upright MRI were observed. In group A, the images acquired in the supine position (dedicated and 1.5T MRI) documented in 21 cases a traumatic tear (group 2A) and in 36 cases a degenerative tear (group 2B). In group 2A, weight-bearing MRI showed presence of unstable tear a degenerative unstable meniscal tear only in 19 out of 36 cases. In group 2B, weight-bearing MRI showed only in 9 out 21 cases. Arthroscopy confirmed weight-bearing MRI diagnosis in all cases. This new approach to meniscus pathology gives an important contribution to a better management of a diagnostic-therapeutic approach in which standard MRI has not played a key role, so far. PMID:23199751

Barile, Antonio; Conti, Laura; Lanni, Giuseppe; Calvisi, Vittorio; Masciocchi, Carlo

2012-11-28

339

TREATMENT OPTIONS IN FULL THICKNESS ROTATOR CUFF TEARS  

Microsoft Academic Search

Increasing interest in shoulder pathology during the last decades has considerably diversified the possible treatment options of full thickness rotator cuff tears. This review of the recent literature combined with information gathered during recent European shoul- der meetings attempts to summarize present trends. Every full thickness cuff tear, except for the acute traumatic tear in younger patients, should always benefit

F. W. J. HANDELBERG

2001-01-01

340

Treatment Options for Rotator Cuff Tears: A Guide for Adults  

MedlinePLUS

... and how long treatment may take. Treating your rotator cuff tear without surgery Rotator cuff tears are treated without surgery in ... when you should start feeling better. Repairing your rotator cuff tear with surgery How long do I wait before choosing surgery? ...

341

Explosive tearing mode reconnection in the magnetospheric tail  

Microsoft Academic Search

A speculative model for the nonlinear phase of the collisionless tearing instability is developed for the case of a single long wavelength tearing mode. Using an energy principle formalism, we find that the nonlinear growth rate is linearly proportional to the mode amplitude. Hence in the nonlinear phase, the tearing mode grows explosively in time, and saturates when the width

A. A. Galeev; F. V. Coroniti; M. Ashour-Abdalla

1978-01-01

342

The tearing mode instability in a partially ionized plasma  

Microsoft Academic Search

The resistive tearing mode instability is a mechanism that in some cases will render unstable an MHD equilibrium of a plasma that is ideally stable, i.e., stable if no dissipative processes are taken into account. The tearing instability can be pictured as a tearing and reconnection of magnetic field lines that have a local reversal in direction, due to a

N. F. Cramer; I. J. Donnelly

1979-01-01

343

Biomechanical study on tibialis posterior tendon transfers.  

PubMed

Two methods are used to route the tibialis posterior tendon anteriorly to achieve dorsiflexion: (1) around the medial side of the tibia, or the subcutaneous route; and (2) through the interosseous membrane, or the interosseous route. This study determined the effect of site of tendon insertion on ankle and foot motions and compared the efficacy of both routes. Eleven fresh normal cadaveric legs were used. The detached tibialis posterior tendon was transferred anteriorly through the interosseous membrane and anchored to the first cuneiform along the first metatarsal axis by a barbed staple. The specimen was mounted on a mechanical testing machine. Tension was applied to the tendon and ankle and foot motions were measured. The experimental procedure was repeated with tendon insertion along the second metatarsal axis and serially through to the fifth metatarsal axis. The entire experiment was repeated using the subcutaneous route. The interosseous route was more effective in achieving maximum dorsiflexion with minimal pronation. Shifting the insertion medially caused supination, whereas a more lateral insertion caused pronation. PMID:7554643

Goh, J C; Lee, P Y; Lee, E H; Bose, K

1995-10-01

344

Percutaneous repair of acute Achilles tendon rupture.  

PubMed

Various studies have shown that the operative treatment of a freshly ruptured Achilles tendon is generally considered to be more appropriate than a nonoperative regimen. However, complications in open reconstructions are reported to occur in 11-29%. The method used in this study reduced the risk of complications arising from operation, but simultaneously allowed early postoperative mobilization and functional treatment. It was a percutaneous repair of the Achilles tendon, using two Lengemann extension wires for coadaptation of the ruptured tendon. To fix the rupture site, the authors used a fibrin sealant. The spikes of the wire were hooked in at the fascia of the soleus muscle. Via a big, curved needle, the wire was placed in the distal stumps of the ruptured tendon and guided out laterally and medially above the calcaneus. After blocking the wires distally, the fibrin sealant was applied at the rupture site. The current report describes this method of treatment in 66 patients. The postoperative observation period was 1 year. Sixty-four patients were male and two were female. Their average age was 42 years. The Achilles tendon ruptures occurred during sporting activities and were treated by operation within 22 hours on average. The outcome was very good in 98%. One patient (2%) suffered a rerupture due to trauma. There were no other complications. PMID:15132929

Gorschewsky, Ottmar; Pitzl, Martin; Pütz, Andrej; Klakow, Andreas; Neumann, Wolfram

2004-04-01

345

Posterior tibial tendon dysfunction and MR imaging in rheumatoid arthritis.  

PubMed

We present the case of a patient with long-standing rheumatoid arthritis and an acute onset of total dysfunction of the posterior tibial tendon. On MRI, a rupture of the tendon was apparent. Intraoperatively, however, massive tenosynovitis with stricture of the tendon was identified as the cause of posterior tibial tendon dysfunction. This case illustrates a pitfall in MRI imaging with potential diagnostic and therapeutic consequences. PMID:12120910

Hasler, Paul; Hintermann, Beat; Meier, Monika

2002-05-01

346

Gene transfer to the tendon-bone insertion site  

Microsoft Academic Search

This study investigated whether gene transfer to the tendon-bone insertion site is possible during early tendon-transplant healing using viral vectors. In addition, we evaluated the optimal gene delivery technique for an in vivo adenoviral gene transfer to a tendon-bone insertion site in a bone tunnel. Twenty-six rabbits underwent a bilateral transfer of the flexor digitorum longus tendon into a bone

Christian Lattermann; Boris A. Zelle; Janey D. Whalen; Axel W. A. Baltzer; Paul D. Robbins; Christopher Niyibizi; Christopher H. Evans; Freddie H. Fu

2004-01-01

347

Characterization of age-related changes of tendon stem cells from adult human tendons.  

PubMed

PURPOSE: The present study evaluated the presence of stem cells in hamstring tendons from adult subjects of different ages. The aim was to isolate, characterize and expand these cells in vitro, and to evaluate whether cell activities are influenced by age. METHODS: Tendon stem cells (TSCs) were isolated through magnetic sorting from the hamstring tendons of six patients. TSC percentage, morphology and clonogenic potential were evaluated, as well as the expression of specific surface markers. TSC multi-potency was also investigated as a function of age, and quantitative polimerase chain reaction was used to evaluate gene expression of TSCs cultured in suitable differentiating media. RESULTS: The presence of easily harvestable stem cell population within adult human hamstring tendons was demonstrated. These cells exhibit features such as clonogenicity, multi-potency and mesenchymal stem cells markers expression. The age-related variations in human TSCs affect the number of isolated cells and their self-renewal potential, while multi-potency assays are not influenced by tendon ageing, even though cells from younger individuals expressed higher levels of osteogenic and adipogenic genes, while chondrogenic genes were highly expressed in cells from older individuals. CONCLUSIONS: These results may open new opportunities to study TSCs to better understand tendon physiology, healing and pathological processes such as tendinopathy and degenerative age-related changes opening new frontiers in the management of tendinopathy and tendon ruptures. PMID:23503946

Ruzzini, Laura; Abbruzzese, Franca; Rainer, Alberto; Longo, Umile Giuseppe; Trombetta, Marcella; Maffulli, Nicola; Denaro, Vincenzo

2013-03-16

348

Closed Zone III Rupture of the Flexor Digitorum Profundus Tendons of the Right Index, Long, and Ring Fingers in a Bowler: Gutterball Syndrome  

Microsoft Academic Search

Zone III flexor tendon injuries are relatively rare in comparison to other flexor tendon injuries in zones I, II, IV, and\\u000a V. Often, these are open injuries resulting from an electrical device like a saw; however, closed injures are even rarer,\\u000a and those mid-substance ruptures resulting from bowling with no evidence of underlying tendinopathy from diseases like gout\\u000a are highly

Srdjan Andrei Ostric; Robert C. Russell; Jason Petrungaro

2010-01-01

349

Conservative treatment and rotator cuff tear progression.  

PubMed

There is no definite consensus on the best management for patients with rotator cuff tears. No randomized controlled studies have compared the outcome of surgical versus conservative treatment. The described successful rate of conservative treatment varies widely, from 33 to 92%. Even though current evidence is not sufficient to allow definitive conclusions on conservative treatment of rotator cuff tears, non-operative management is often recommended in such patients. Prognostic factors seem to be clinical presentation, duration of symptoms and tear size. The best programme for conservative treatment is not defined. Physical therapy consists of stretching and strengthening exercises. The characteristics of exercise programmes are not standardized. In clinical practice, intra-articular injections are commonly used for treatment of shoulder pain. Systemic pharmacotherapy for patients with shoulder pain consists of non-steroidal anti-inflammatory drugs. Recently, cyclo-oxygenase-2-selective inhibitors have been introduced for management of shoulder pain. To date, few randomized controlled trials are available on conservative management of rotator cuff tears, and therefore further studies are required to clarify its role in such patients. PMID:21986048

Longo, Umile Giuseppe; Franceschi, Francesco; Berton, Alessandar; Maffulli, Nicola; Droena, Vincenzo

2011-10-04

350

Temperture anisotropy effect on the tearing mode  

Microsoft Academic Search

Previous study of the Plasma temperature anisotropy in the current sheet have shown that alphaj > 1 (alphaj = Tj,perp\\/Tj,para , j = ion or electron) significantly enhances the growth rate of tearing instability (TI), and the maximum growth wave length shift for shorter by the linear theory [Chen & Palmadesso, Phys. Fluds 1984; Ambrosiano, Geophys. Res. 1986]. Recent result

K. Haijima; K. Tanaka; M. Fujimoto; I. Shinohara

2006-01-01

351

FLR effects in nonlinear tearing mode reconnection  

Microsoft Academic Search

The influence of ion Finite Larmor Radius (FLR) effects in the evolution of the tearing mode is studied analytically and numerically. We use a gyrofluid extension of the usual two-field, reduced MHD equations, where closure is provided by the Gyrokinetic Poisson's law. Two-dimensional slab geometry is adopted. In the linear regime it is shown that significative enhancement of the growth

Nuno Loureiro; Steve Cowley; William Dorland; Greg Hammett; Alexander Schekochihin

2006-01-01

352

Tensile and tear properties of dental dam.  

PubMed

The tensile and tear properties of highly extensible latex are sensitive to specimen shape. Three specimen shapes (ASTM D412 Die C dumbbell tensile specimen, rectangular tensile specimen with 1.74 mm hole, and ASTM D624 Die C tear specimen) were evaluated for proposed ANSI/ADA specification #90 for dental dams. Fresh and aged dental dams from two manufacturers (Aseptico and Hygenic) in three weights (thin, medium, and heavy) and from two other manufacturers (Ivory and Ivoclar) in one weight (medium) were tested. Means and standard deviations of 10 specimens for tensile strength (MPa), elongation (%), and tear strength (kN/m) are included herein. Data were analyzed by analysis of variance. Means were compared by a Tukey-Kramer interval calculated at the 0.05 significance level. The use of the dumbbell and tear specimens for the evaluation of dental dam should be reconsidered. The rectangular specimen with a hole is recommended for use in the proposed specification because of its sensitivity to condition (fresh versus aged) and manufacturer. PMID:8632138

Svec, T A; Powers, J M; Ladd, G D; Meyer, T N

1996-05-01

353

Work of flexion after tendon repair with various suture methods  

Microsoft Academic Search

After flexor tendon repair there is often increased resistance to tendon gliding at the repair site, which is greater for techniques using increased suture strands or suture material. This increased “friction” may be measured as the “work of flexion” in the laboratory setting. Tendon repairs performed in zone 2 in human cadaver hands using the two strand Kessler, the lateral

M. Aoki; P. R. Manske; D. L. Pruitt; B. J. Larson

1995-01-01

354

Giant cell tumour of the tendon sheath in the foot  

Microsoft Academic Search

Giant cell tumour of the tendon sheath is a benign, solitary lesion, which is less common in foot than in hand. Recurrence is the most common complication after excision. We report a case of GCT-TS in the flexor tendon of the right big toe in 28 years old lady. The mass was excised widely with preservation of the flexor tendon.

Mohie Eldin Fadel; Axel Schulz; Ralph Linker; Jörg Jerosch

2006-01-01

355

The role of tendon microcirculation in Achilles and patellar tendinopathy  

Microsoft Academic Search

Tendinopathy is of distinct interest as it describes a painful tendon disease with local tenderness, swelling and pain associated with sonographic features such as hypoechogenic texture and diameter enlargement. Recent research elucidated microcirculatory changes in tendinopathy using laser Doppler flowmetry and spectrophotometry such as at the Achilles tendon, the patellar tendon as well as at the elbow and the wrist

Karsten Knobloch

2008-01-01

356

Patellar tendon healing after removal of its central third  

Microsoft Academic Search

The central third of the patellar tendon of the right knee was removed in 40 adult New Zealand White (NZW) rabbits. The animals were divided into two groups of 20 animals each. In group 1 the tendon defect was left open and in group 2 the tendon defect was closed. The peritenon was closed in all cases. The animals were

Giuseppe Milano; Antonio Gigante; Alfredo Schiavone Panni; Pier Damiano Mulas; Carlo Fabbriciani

2001-01-01

357

[MRI diagnosis of injuries and diseases of peroneal tendons].  

PubMed

Injuries of the peroneus tendons are common and both the athlete and the older population are at risk. MR imaging is a useful technique for revealing injuries of the peroneus tendons as well as showing anatomic factors associated with these lesions. This article reviews clinical factors and MR imaging characteristics of injuries of the peroneus tendons. PMID:11402870

Rademaker, J; Teichgräber, U K; Schröder, R J; Oestmann, J W; Felix, R

2001-01-01

358

Measurement of stress strain and vibrational properties of tendons  

Microsoft Academic Search

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

Gian Marco Revel; Alessandro Scalise; Lorenzo Scalise

2003-01-01

359

Flucloxacillin reduces stiffness following flexor tendon repair.  

PubMed

To determine the benefit of antibiotic prophylaxis on postoperative mobility in flexor tendon repairs, case notes of 72 flexor tendon injuries in twenty four patients were analyzed retrospectively (2001-2003). Only patients with non-contaminated injuries from sharp instruments in flexor zone 2 were included in the study; 57% were male, average age was 31 years, and 24% were smokers. The majority of injuries were caused by metal blades (45%). Most tendons were repaired with modified Kessler technique (69%). Twenty-five percent received intravenous flucloxacillin or co-amoxiclav perioperatively. Reduced total active motion (TAM, found in 25% of patients more than 7 weeks after surgical repair) significantly complicated patients without perioperative intravenous flucloxacillin cover. The use of intravenous perioperative flucloxacillin is a plausible adjunct in surgery to prevent postoperatively reduced mobility. PMID:18780024

Schumacher, Hagen H A; James, Nick K

2008-04-24

360

Tendoscopy of the posterior tibial tendon.  

PubMed

Posteromedial ankle complaints are most often caused by a disorder of the posterior tibial tendon. Two predominant groups of patients can be distinguished: the first involves younger patients who have some form of systemic inflammatory disease; the second involves older patients whose dysfunction is caused by chronic overuse. This article illustrates endoscopy of the posterior tibial tendon in a group of patients who had diverse pathology. None of the patients showed postoperative complications. All showed a quick recovery, early mobilization, none or mild postoperative pain, and nice wound healing. Although not all patients were free of complaints, all were satisfied with the intervention itself. Tendoscopy of the poterior tibial tendon offers the advantage of less morbidity, reduction of the postoperative pain, early mobilization, no wound healing problems and outpatient treatment. PMID:16798520

Bulstra, Gythe H; Olsthoorn, Paul G M; Niek van Dijk, C

2006-06-01

361

Tendon-Derived Stem Cells (TDSCs): From Basic Science to Potential Roles in Tendon Pathology and Tissue Engineering Applications  

Microsoft Academic Search

Traditionally, tendons are considered to only contain tenocytes that are responsible for the maintenance, repair and remodeling\\u000a of tendons. Stem cells, which are termed tendon-derived stem cells (TDSCs), have recently been identified in tendons. This\\u000a review aims to summarize the current information about the in vitro characteristics of TDSCs, including issues related to TDSC isolation and culture, their cell morphology,

Pauline Po Yee Lui; Kai Ming Chan

362

Simultaneous rupture of the quadriceps tendon with contralateral patellar tendon rupture: an unusual case and a review of the literature  

Microsoft Academic Search

Simultaneous rupture of quadriceps tendon with contralateral patellar tendon is very rare. There are only two case reports\\u000a in English literature. We report the case of a healthy 41-year-old female with simultaneous rupture of her left quadriceps\\u000a tendon and right patellar tendon. There were no known precipitating factors for this injury. Surgical repair and early rehabilitation\\u000a achieved satisfactory outcome.

A. Jalgaonkar; A. Rafee; O. Haddo; S. Sarkar

2008-01-01

363

Exponentially Growing Tearing Modes in Rijnhuizen Tokamak Project Plasmas  

NASA Astrophysics Data System (ADS)

The local measurement of the island width w, around the resonant surface, allowed a direct test of the extended Rutherford model [P. H. Rutherford, PPPL Report-2277 (1985)], describing the evolution of radiation-induced tearing modes prior to disruptions of tokamak plasmas. It is found that this model accounts very well for the observed exponential growth and supports radiation losses as being the main driving mechanism. The model implies that the effective perpendicular electron heat conductivity in the island is smaller than the global one. Comparison of the local measurements of w with the magnetic perturbed field B~ showed that w~B~1/2 was valid for widths up to 18% of the minor radius.

Salzedas, F.; Schüller, F. C.; Oomens, A. A.; RTP Team

2002-02-01

364

Tendon ruptures: mallet, flexor digitorum profundus.  

PubMed

Mallet injuries are the most common closed tendon injury in the athlete. Flexor digitorum profundus ruptures are rare in baseball, but are common injuries in contact sports. The diagnosis for each condition is based on clinical examination, although radiographs should be evaluated for a possible bony component. Treatment for mallet injury depends on the athlete's goals of competition and understanding of the consequences of any treatment chosen. Gripping, throwing, and catching would be restricted or impossible with the injured finger immobilized. Treatment of FDP ruptures is almost always surgical and requires reattachment of the torn tendon to the distal phalanx. PMID:22883898

Yeh, Peter C; Shin, Steven S

2012-07-03

365

Percutaneous & Mini Invasive Achilles tendon repair  

PubMed Central

Rupture of the Achilles tendon is a considerable cause of morbidity with reduced function following injury. Recent studies have shown little difference in outcome between the techniques of open and non-operative treatment using an early active rehabilitation programme. Meta-analyses have shown that non-operative management has increased risk of re-rupture whereas surgical intervention has risks of complications related to the wound and iatrogenic nerve injury. Minimally invasive surgery has been adopted as a way of reducing infections rates and wound breakdown however avoiding iatrogenic nerve injury must be considered. We discuss the techniques and outcomes of percutaneous and minimally invasive repairs of the Achilles tendon.

2011-01-01

366

The Role of Wrist Magnetic Resonance Arthrography in Diagnosing Triangular Fibrocartilage Complex Tears  

PubMed Central

Objectives: The aims of the study were to evaluate the role of magnetic resonance arthrography (MRA) of the wrist in detecting full-thickness tears of the triangular fibrocartilage complex (TFCC) and to compare the results of the magnetic resonance arthrography (MRA) with the gold standard arthroscopic findings. Methods: The study was performed at King Hussein Medical Center, Amman, Jordan, between January 2008 and December 2011. A total of 42 patients (35 males and 7 females) who had ulnar-sided wrist pain and clinical suspicions of TFCC tears were included in the study. All patients underwent wrist magnetic resonance arthrography (MRA) and then a wrist arthroscopy. The results of MRA were compared with the arthroscopic findings. Results: After comparison with the arthroscopic findings, the MRA had three false-negative results (sensitivity = 93%) and no false-positive results. A total of 39 patients were able to return to work. Satisfaction was high in 38 of the patients and 33 had satisfactory pain relief. The sensitivity of the wrist MRA in detecting TFCC full-thickness tears was 93% (39), and specificity was 80% (16/20). The overall accuracy of wrist arthroscopy in detecting a full-thickness tear of the TFCC in our study was 85% (29/34). Conclusion: These results illustrate the role of wrist MRA in assessing the TFCC pathology and suggest its use as the first imaging technique, following a plain X-ray, in evaluating patients with chronic ulnar side wrist pain with suspected TFCC injuries.

Al-Hiari, Asem A.

2013-01-01

367

Postirradiation Dynamic Tear and Charpy-V Performance of 12-in. Thick A533-B Steel Plates and Weld Metal.  

National Technical Information Service (NTIS)

Charpy-V (C sub V) and dynamic tear (DT) test comparisons are developed for the irradiated condition of two 12 in. thick A533-B steel plates and a submerged arc weld deposit. Materials for the investigation were donated by the U.S. Atomic Energy Commissio...

J. R. Hawthorne

1971-01-01

368

Comparative biochemical analysis of sea urchin peristome and rat tail tendon collagen.  

PubMed

We report here a biochemical comparison between type 1 rat tail tendon collagen and collagen isolated from sea urchin peristome tissue. The sea urchin collagen consisted of two species of apparent mol masses, 140 and 116 kDa. Amino acid compositional analysis of the 140 and 116 kDa species revealed the presence of hydroxyproline and hydroxylysine as well as a glycine content of 28.1 mol.%. In solubility experiments the rat tail tendon collagen was found to precipitate at sodium chloride concentrations between 1 and 2 M while peristome collagen remained soluble at salt concentrations as high as 4 M. Incubation of the peristome and rat tail tendon collagen preparations with a sea urchin collagenase/gelatinase resulted in cleavage of the former but not the latter collagen. Upon heat denaturation at 60 degrees C, however, the rat tail tendon collagen served as a substrate for the gelatinase. Cyanogen bromide cleavage of rat tail and peristome collagens generated largely unique peptide maps. Collectively, these results suggest that structural differences exist between echinoderm and vertebrate type 1 collagens. PMID:9226889

Robinson, J J

1997-06-01

369

Achilles Tendon Rupture: Avoiding Tendon Lengthening during Surgical Repair and Rehabilitation  

PubMed Central

Achilles tendon rupture is a serious injury for which the best treatment is still controversial. Its primary goal should be to restore normal length and tension, thus obtaining an optimal function. Tendon elongation correlates significantly with clinical outcome; lengthening is an important cause of morbidity and may produce permanent functional impairment. In this article, we review all factors that may influence the repair, including the type of surgical technique, suture material, and rehabilitation program, among many others.

Maquirriain, Javier

2011-01-01

370

Morphology of deltoid origin and end tendons - a generic model  

PubMed Central

This study provides a model of the complex deltoid origin and end tendons, as a basis for further anatomical, biomechanical and clinical research. Although the deltoid is used in transpositions with upper limb paralysis, its detailed morphology and segmentation has not been object of much study. Morphologically, the deltoid faces two distinct challenges. It closely envelops a ball joint, and it reduces its width over a short distance from a very wide origin along clavicle, acromion and spina scapula, to an insertion as narrow as the humerus. These challenges necessitate specific morphological tendon adaptations. A qualitative model for these tendons is developed by the stepwise transformation of a unipennate muscle model into a functional deltoid muscle. Each step is the solution to one of the mentioned morphological challenges. The final model is of an end tendon consisting of a continuous succession of bipennate end tendon blades centrally interspaced by unipennate tendon parts. The origin tendon consists of lamellae that interdigitate with the end tendon blades, creating a natural segmentation. The model is illustrated by qualitative dissection results. In addition, in view of a proliferation of terms found in the literature to describe deltoid tendons, tendon concepts are reviewed and the systematic use of the unique and simple terminology of ‘origin and end tendons’ is proposed.

Leijnse, J N A L; Han, S-H; Kwon, Y H

2008-01-01

371

Tendon matrix composition and turnover in relation to functional requirements  

PubMed Central

Tendons are dense regular connective tissue structures that are defined based on their anatomical position of connecting muscle to bone. Despite these obvious commons features tendons from different locations within the body show remarkable variation in terms of their morphological, molecular and mechanical properties which relates to their specialized function. An appreciation of these differences is necessary to understand all aspects of tendon biology in health and disease. In our work, we have used a combination of mechanical assessment, histological measurements and molecular analysis of matrix in functionally distinct tendons to determine relationships between function and structure. We have found significant differences in material and molecular properties between spring-like tendons that are subjected to high strains during locomotion and positional tendons which are subjected to much lower strains. Furthermore, we have data to suggest that not only is the matrix composition different but also the ability of cells to synthesize and degrade the matrix (matrix turnover) varies between tendon types. We propose that these differences relate to the magnitude of strain that the tendon experiences during normal activities in life. Tendon cells may be preprogrammed during embryological development for the strain they will encounter in life or may simply respond to the particular strain environment they are subjected to. The elucidation of controlling mechanisms resulting in tendon cell specialization will have important consequences for cell based therapies and engineering strategies to repair damaged tendons.

Birch, Helen L

2007-01-01

372

Conflicts, snapping and instability of the tendons. Pictorial essay  

PubMed Central

Conflicts, snapping and instability of the tendons are common, and ultrasound (US) is the method of choice for evidencing these conditions thanks to the possibility to perform dynamic maneuvers during imaging studies. A conflict can occur between a tendon and a bone structure, other tendons, the retinacula or pulleys. Snapping can occur due to instability caused by rupture of the retinaculum, conflict between a thickened retinaculum and a bone prominence or due to an abnormal position of the tendon. Instability can occur due to insufficient ability of the retinaculum to keep the tendons in the bone groove or its failure to hold the tendons applied to the bone. The technique for evidencing conflicts, snapping and instability of the tendons is very demanding because it requires a thorough knowledge of the US appearance and dynamic maneuvers. However, at the present time US examination completed with dynamic maneuvers is the investigation of choice for evidencing these disorders and providing the clinicians with the necessary information.

Fantino, Olivier; Borne, J.; Bordet, Bertrand

2012-01-01

373

Cadaveric limb analysis of tendon length discrepancy of posterior tibial tendon transfer through the interosseous membrane.  

PubMed

The posterior tibial tendon transfer through the interosseous membrane, as popularized by Watkins in 1954, is a procedure for treating reducible eversion and dorsiflexory paresis used by lower extremity foot and ankle surgeons. The posterior tibial tendon has been transferred to various locations on the midfoot for equinus and equinovarus deformities. Dorsiflexory paresis is a common symptom in equinovarus deformity, clubfoot deformity, Charcot-Marie-Tooth disease, leprosy, mononeuropathy, trauma to the common peroneal nerve, cerebrovascular accident, and Duchenne's muscular dystrophy. The main difficulty with this procedure, often discussed by surgeons, is inadequate tendon length, making anchoring to the cuneiforms or cuboid difficult. The goal of our cadaveric study was threefold. First, we sought to determine whether the tendon length is sufficient when transferring the posterior tibial tendon to the dorsum of the foot through the interosseous membrane for a dynamic or a static transfer. Second, we wished to describe the surgical technique designed to obtain the maximal length. Finally, we sought to discuss the strategies used when the tendon length for transfer is insufficient. PMID:23369302

Pappas, Alexander J; Haffner, Kyle E; Mendicino, Samuel S

2013-01-28

374

Partial rupture of the distal biceps tendon  

Microsoft Academic Search

We report on 7 cases of partial rupture of the distal biceps tendon. The mean patient age was 52 years (range, 38-58 years). There were 5 men and 2 women. The dominant arm was affected in all 7 patients. Pain was the chief complaint in all patients. Immobilization and physiotherapy were attempted in all patients, and 4 had at least

Dimitris G. Vardakas; Douglas S. Musgrave; Sokratis E. Varitimidis; Felix Goebel; Dean G. Sotereanos

2001-01-01

375

Pectoralis major tendon ruptures: when to operate  

Microsoft Academic Search

The treatment of pectoralis major tendon ruptures has been the subject of much debate. The classical history of the injury is forced abduction and external rotation. The cases of two patients (an amateur rugby union player and a recreational snowboarder) are reported. The diagnosis was made by clinical examination in both patients, and both were operated on more than two

J F Quinlan; M Molloy; B J Hurson

2002-01-01

376

Engaging Stem Cells for Customized Tendon Regeneration  

PubMed Central

The need for a consistent therapeutic approach to tendon injury repair is long overdue. Patients with tendon microtears or full ruptures are eligible for a wide range of invasive and non invasive interventions, often subjectively decided by the physician. Surgery produces the best outcomes, and while studies have been conducted to optimize graft constructs and to track outcomes, the data from these studies have been inconclusive on the whole. What has been established is a clear understanding of healthy tendon architecture and the inherent process of healing. With this knowledge, tissue regeneration efforts have achieved immense progress in scaffold design, cell line selection, and, more recently, the appropriate use of cytokines and growth factors. This paper evaluates the plasticity of bone-marrow-derived stem cells and the elasticity of recently developed biomaterials towards tendon regeneration efforts. Mesenchymal stem cells (MSCs), hematopoietic progenitor cells, and poly(1,8-octanediol co-citrate) scaffolds (POC) are discussed in the context of established grafting strategies. With POC scaffolds to cradle the growth of MSCs and hematopoietic progenitor cells, developing a fibroelastic network guided by cytokines and growth factors may contribute towards consistent graft constructs, enhanced functionality, and better patient outcomes.

Thaker, Hatim; Sharma, Arun K.

2012-01-01

377

Prestressed concrete using KEVLAR reinforced tendons  

Microsoft Academic Search

KEVLAR is a high strength, high modulus synthetic fiber manufactured by the E.I. DuPont de Nemours Company. The fiber is resistant to chloride and alkali attack. The resistance is enhanced when the fibers are assembled into a resin matrix and fabricated as rods. These properties suggest that KEVLAR reinforced rods may be a substitute for high strength steel prestress tendons

Dolan

1989-01-01

378

Traumatic dislocations of the peroneal tendons  

Microsoft Academic Search

Traumatic dislocation of the peroneal tendons is an often unrecognized injury which has been reported to occur most commonly during snow skiing. The strength of the peroneal retinaculum is exceeded during resist ance to violent passive dorsiflexion or to inversion stress. Pain, swelling, and ecchymosis may hinder early diagnosis; however, intense retromalleolar pain on ac tive eversion is a specific,

Scott R. Arrowsmith; Lamar L. Fleming; Fred L. Allman

1983-01-01

379

How tendons buffer energy dissipation by muscle.  

PubMed

To decelerate the body and limbs, muscles lengthen actively to dissipate energy. During rapid energy-dissipating events, tendons buffer the work done on muscle by storing elastic energy temporarily, then releasing this energy to do work on the muscle. This elastic mechanism may reduce the risk of muscle damage by reducing peak forces and lengthening rates of active muscle. PMID:23873133

Roberts, Thomas J; Konow, Nicolai

2013-10-01

380

Mechanical Compromise of Partially Lacerated Flexor Tendons  

PubMed Central

Background Tendons function to transmit loads from muscle to move and stabilize joints and absorb impacts. Functionality of lacerated tendons is diminished, however clinical practice often considers surgical repair only after 50% or more of the tendon is lacerated, the “50% rule.” Few studies provide mechanical insight into the “50% rule.” Method of Approach In this study cyclic and static stress relaxation tests were performed on porcine flexor tendons before and after a 0.5, 1.0, 2.0, or 2.75mm deep transverse, mid-substance laceration. Elastic and viscoelastic properties, such as maximum stress, change in stress throughout each test, and stiffness, were measured and compared pre- and post-laceration. Results Nominal stress and stiffness parameters decreased, albeit disproportionately in magnitude, with increasing percent loss of cross-sectional area. Conversely, mean stress at the residual area (determined using remaining intact area at the laceration cross-section) exhibited a marked increase in stress concentration beginning at 47.2% laceration using both specified load and constant strain analyses. Conclusions The marked increase in stress concentration beginning near 50% laceration provides mechanical insight into the “50% rule.” Additionally, a drastic decrease in viscoelastic stress parameters after only an 8.2% laceration suggests that time-dependent mechanisms protecting tissues during impact loadings are highly compromised regardless of laceration size.

Kondratko, Jaclyn; Duenwald-Kuehl, Sarah; Lakes, Roderic; Vanderby, Ray

2013-01-01

381

Dynamics of goat distal hind limb muscle-tendon function in response to locomotor grade  

PubMed Central

Summary The functional roles of the lateral gastrocnemius (LG), medial gastrocnemius (MG) and superficial digital flexor (SDF) muscle–tendon units (MTUs) in domestic goats (N=6) were studied as a function of locomotor grade, testing the hypothesis that changes in distal limb muscle work would reflect changes in mechanical work requirements while goats walked or trotted on the level, 15 deg. decline and 15 deg. incline. As steep terrain-adapted animals, changes in muscle work output are expected to be particularly important for goats. In vivo muscle–tendon forces, fascicle length changes and muscle activation were recorded via tendon force buckles, sonomicrometry and electromyography to evaluate the work performance and elastic energy recovery of the three distal MTUs. These recordings confirmed that fascicle strain and force within goat distal hind limb muscles are adjusted in response to changes in mechanical work demand associated with locomotor grade. In general, muscle work was modulated most consistently by changes in fascicle strain, with increased net shortening (P<0.001) observed as goats switched from decline to level to incline locomotion. Peak muscle stresses increased as goats increased speed from a walk to a trot within each grade condition (P<0.05), and also increased significantly with grade (P<0.05 to P<0.01). Due to the increase in net fascicle shortening and muscle force, net muscle work per cycle also increased significantly (P<0.05 to P<0.005) as goats switched from decline to level to incline conditions (LG work: 20 mJ to 56 mJ to 209 mJ; MG work: –7 mJ to 34 mJ to 179 mJ; SDF work: –42 mJ to 14 mJ to 71 mJ, at a 2.5 ms–1 trot). Although muscle work was modulated in response to changes in grade, the amount of work produced by these three distal pennate muscles was small (being <3%) in comparison with the change in mechanical energy required of the limb as a whole. Elastic energy recovery in the SDF and gastrocnemius (GA) tendons was substantial across all three grades, with the SDF tendon recovering 2.4 times more energy, on average, than the GA tendon. In parallel with the increase in muscle–tendon force, tendon energy recovery also increased as goats increased speed and changed gait, reaching the highest levels when goats trotted on an incline at 2.5 ms–1 (GA: 173 mJ; SDF: 316 mJ). In general, tendon elastic energy exceeded net muscle work across all grade and gait conditions. These results demonstrate, for the first time in a quadruped, similar findings to those observed in ankle extensor muscles in humans, wallabies, turkeys and guinea fowl, suggesting that distal muscle–tendon architecture more generally favors a design for economic force production and tendon elastic energy recovery, with the majority of limb work during incline or decline running performed by larger proximal muscles.

McGuigan, M. Polly; Yoo, Edwin; Lee, David V.; Biewener, Andrew A.

2009-01-01

382

Tearing of free-standing graphene  

NASA Astrophysics Data System (ADS)

We examine the fracture mechanics of tearing graphene. We present a molecular dynamics simulation of the propagation of cracks in clamped, free-standing graphene as a function of the out-of-plane force. The geometry is motivated by experimental configurations that expose graphene sheets to out-of-plane forces, such as back-gate voltage. We establish the geometry and basic energetics of failure and obtain approximate analytical expressions for critical crack lengths and forces. We also propose a method to obtain graphene's toughness. We observe that the cracks’ path and the edge structure produced are dependent on the initial crack length. This work may help avoid the tearing of graphene sheets and aid the production of samples with specific edge structures.

Moura, M. J. B.; Marder, M.

2013-09-01

383

Blood supply of the flexor hallucis longus tendon with regard to dancer's tendinitis: injection and immunohistochemical studies of cadaver tendons.  

PubMed

The flexor hallucis longus is the most common site of lower extremity tendon disorders in ballet dancers. Reduced vascularity is an important factor contributing to tendon degeneration and rupture under strain. A study was conducted on the vascular pattern of the human flexor hallucis longus tendon with injection techniques and immunohistochemically by using antibodies against laminin. Blood supply arose from the posterior tibial and the medial plantar artery. Peritendinous blood vessels penetrated the tendon and anastomosed with a longitudinally oriented intratendinous network. Injection specimens and immunohistochemistry revealed one avascular zone in which the tendon passed behind the talus and a second in which the tendon wrapped around the first metatarsal head. These are the most typical areas for tendon degeneration and rupture. PMID:12956563

Petersen, Wolf; Pufe, Thomas; Zantop, Thore; Paulsen, Friedrich

2003-08-01

384

Apomictic maternal diploids in tetraploid Job's tears  

Microsoft Academic Search

Two cases of reversion to diploidy were observed in autotetraploid Job's tears (Coix lacryma-jobi L. 4n = 40) out of a total of 1,112 plants examined over a period of 7 years. One of these was a trisomie (2n = 21) and the other a disomic (2n = 20), derived from apomictic development ofn+1 andn maternal gametes of the tetraploid,

J. Venkateswarlu; Panuganti N. Rao

1975-01-01

385

[The group intoxication by tear-gas].  

PubMed

The case of group intoxication of 52 pupils by tear CS gas (2-chlorobenzelidenemaloninitrile) at school is presented. The most often clinical signs observed at hospital admitted children, at 13-16 year old were detail described. The special attend was given for 4 cases, heavy clinical intoxication observed for young girls. The clinical symptoms, action of xenobiotics and clinical treatment compare with literature data, were discussed. PMID:15517936

Borowiak, Krzysztof S; Waloszczy, Piotr; Machoy-Mokrzy?ska, Anna; Jarmo?owicz, Zofia

2004-04-01

386

Tearing Instability in Relativistic Magnetically Dominated Plasmas  

NASA Astrophysics Data System (ADS)

Many astrophysical sources of high energy emission, such as black hole magnetospheres, superstrongly magnetized neutron stars (magnetars), and probably relativistic jets in Active Galactic Nuclei and Gamma Ray Bursts involve relativistically magnetically dominated plasma. In such plasma the energy density of magnetic field greatly exceeds the thermal and the rest mass energy density of particles. Therefore the magnetic field is the main reservoir of energy and its dissipation may power the bursting emission from these sources, in close analogy to Solar flares. One of the principal dissipative instabilities that may lead to release of magnetic energy is the tearing instability. In this paper we study (see also10), both analytically and numerically, the development of tearing instability in relativistically magnetically-dominated plasma using the framework of resistive magnetodynamics. We confirm and elucidate the previously obtained result on the growth rate of the tearing mode: the shortest growth time is the same as in the case of classical non-relativistic MHD, namely ? = ? {? a ? d } where ?a is the Alfvén crossing time and ?d is the resistive time of a current layer. The reason for this coincidence is the close similarity between the governing equations, especially in the quasi-equilibrium approximation. In particular, the role of the mass density of nonrelativistic MHD is played by the mass-energy density of the magnetic field, ? = B2/8?c2.

Barkov, M. V.; Komissarov, S. S.; Lyutikov, M.

2008-09-01

387

Tearing instability in relativistic magnetically dominated plasmas  

NASA Astrophysics Data System (ADS)

Many astrophysical sources of high-energy emission such as black hole magnetospheres, superstrongly magnetized neutron stars (magnetars) and probably relativistic jets in active galactic nuclei and gamma-ray bursts involve relativistically magnetically dominated plasma. In such plasma the energy density of magnetic field greatly exceeds the thermal and the rest mass energy density of particles. Therefore, the magnetic field is the main reservoir of energy and its dissipation may power the bursting emission from these sources, in close analogy to solar flares. One of the principal dissipative instabilities that may lead to release of magnetic energy is the tearing instability. In this paper we study, both analytically and numerically, the development of tearing instability in relativistically magnetically dominated plasma using the framework of resistive magnetodynamics. We confirm and elucidate the previously obtained result on the growth rate of the tearing mode: the shortest growth time is the same as in the case of classical non-relativistic magnetohydrodynamics (MHD), namely , where ?a is the Alfvén crossing time and ?d is the resistive time of a current layer. The reason for this coincidence is the close similarity between the governing equations, especially in the quasi-equilibrium approximation. In particular, the role of the mass density of non-relativistic MHD is played by the mass-energy density of the magnetic field, ? = B2/8?c2.

Komissarov, S. S.; Barkov, M.; Lyutikov, M.

2007-01-01

388

Review of acetabular labral tears in dancers.  

PubMed

Over the past decade numerous articles have been published regarding the hip labrum. Injuries to the labrum are becoming better understood as biomechanical, kinematic, and diagnostic technologies improve. When the last article on acetabular labral tears appeared in the Journal of Dance Medicine and Science in 2006, this injury was widely handled surgically by debridement. Just 5 years later, we see a shift toward preservation and repair of the labrum and correction of morphology when possible. This change in philosophy has come about as new information on the function of the labrum and the stresses placed upon it at extremes of hip range of motion became available. It is now felt that an intact labrum is useful for preserving the hip's articular cartilage. The change in surgical technique has also necessitated a change in rehabilitation protocols focused on protecting the healing labrum and chondral surface. The vast majority of research available for analysis has not been addressed specifically to a dance population, yet most is relevant and helpful in determining better treatment for dancers. This article reviews the latest available data on labral function, stresses on the labrum resulting from dance, clinical and diagnostic detection of labral tears, and outcomes of labral tear treatment in the young athletic population, including dancers. Recommendations are offered to improve data collection and focus for future research. PMID:22687654

Kern-Scott, Ruth; Peterson, Judith R; Morgan, Patrick

2011-01-01

389

Glycosaminoglycans of human rotator cuff tendons: changes with age and in chronic rotator cuff tendinitis  

Microsoft Academic Search

OBJECTIVES--To analyse the glycosaminoglycans of the adult human rotator cuff tendon matrix, to characterise changes in the glycosaminoglycan composition with age and in chronic rotator cuff tendinitis. METHODS--Rotator cuff (supraspinatus) tendons (n = 84) and common biceps tendons (n = 26) were obtained from cadavers with no history of tendon pathology (age range 11-95 years). Biopsies of rotator cuff tendons

G P Riley; R L Harrall; C R Constant; M D Chard; T E Cawston; B L Hazleman

1994-01-01

390

An experimental study of the repair and gliding function of digital flexor tendon following injury  

Microsoft Academic Search

The profundus tendons of young adult chickens have been used to study flexor tendon healing within the digital sheath. Histological observation has shown that the preserved digital sheath prevented the tendon healing with adhesions and that the epitendon played a leading role in the process of tendon repair. Muscle tension must be removed from the sutured site for tendon repair

Yukuo Tokita; Akio Yamaya; Yoshiyasu Ito; Toshiyuki Fukuoka; Kenichiro Uchinishi; Yutaka Yabe

1977-01-01

391

Tearing modes with pressure gradient effect in pair plasmas  

SciTech Connect

The general dispersion relation of tearing mode with pressure gradient effect in pair plasmas is derived analytically. If the pressure gradients of positron and electron are not identical in pair plasmas, the pressure gradient has significant influence at tearing mode in both collisionless and collisional regimes. In collisionless regime, the effects of pressure gradient depend on its magnitude. For small pressure gradient, the growth rate of tearing mode is enhanced by pressure gradient. For large pressure gradient, the growth rate is reduced by pressure gradient. The tearing mode can even be stabilized if pressure gradient is large enough. In collisional regime, the growth rate of tearing mode is reduced by the pressure gradient. While the positron and electron have equal pressure gradient, tearing mode is not affected by pressure gradient in pair plasmas.

Cai Huishan; Li Ding; Zheng Jian [Key Laboratory of Basic Plasma Physics, School of Science, CAS, University of Science and Technology of China, Hefei 230026 (China)

2009-04-15

392

Design and performance of a fiber bragg grating displacement sensor for movement measurement of tendon and ligament  

NASA Astrophysics Data System (ADS)

Biomechanical studies often involve measurements of the strains developed in tendons or ligaments in posture or locomotion. Fiber optic sensors present an attractive option for measurement of strains in tendons and ligaments due to their low cost, ease of implementation, and increased accuracy compared to other implantable transducers. A new displacement sensor based on fiber Bragg grating and shape memory alloy technology is proposed for the monitoring of tendon and ligament strains in different postures and in locomotion. After sensor calibration in the laboratory, a comparison test between the fiber sensors and traditional camera displacement sensors was carried out to evaluate the performance of the fiber sensor during application of tension to the Achilles tendon. Additional experiments were performed in cadaver knees to assess the suitability of these fiber sensors for measuring ligament deformation in a variety of simulated postures. The results demonstrate that the proposed fiber Bragg grating sensor is a high-accuracy, easily implantable, and minimally invasive method of measuring tendon and ligament displacement.

Ren, Liang; Song, Gangbing; Conditt, Michael; Noble, Philip C.; Li, Hongnan

2007-05-01

393

Low frequency pulsed electromagnetic field affects proliferation, tissue-specific gene expression, and cytokines release of human tendon cells.  

PubMed

Low frequency pulsed electromagnetic field (PEMF) has proven to be effective in the modulation of bone and cartilage tissue functional responsiveness, but its effect on tendon tissue and tendon cells (TCs) is still underinvestigated. PEMF treatment (1.5 mT, 75 Hz) was assessed on primary TCs, harvested from semitendinosus and gracilis tendons of eight patients, under different experimental conditions (4, 8, 12 h). Quantitative PCR analyses were conducted to identify the possible effect of PEMF on tendon-specific gene transcription (scleraxis, SCX and type I collagen, COL1A1); the release of pro- and anti-inflammatory cytokines and of vascular endothelial growth factor (VEGF) was also assessed. Our findings show that PEMF exposure is not cytotoxic and is able to stimulate TCs' proliferation. The increase of SCX and COL1A1 in PEMF-treated cells was positively correlated to the treatment length. The release of anti-inflammatory cytokines in TCs treated with PEMF for 8 and 12 h was significantly higher in comparison with untreated cells, while the production of pro-inflammatory cytokines was not affected. A dramatically higher increase of VEGF-A mRNA transcription and of its related protein was observed after PEMF exposure. Our data demonstrated that PEMF positively influence, in a dose-dependent manner, the proliferation, tendon-specific marker expression, and release of anti-inflammatory cytokines and angiogenic factor in a healthy human TCs culture model. PMID:23345006

de Girolamo, L; Stanco, D; Galliera, E; Viganò, M; Colombini, A; Setti, S; Vianello, E; Corsi Romanelli, M M; Sansone, V

2013-07-01

394

EGR1 and EGR2 Involvement in Vertebrate Tendon Differentiation*  

PubMed Central

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.

Lejard, Veronique; Blais, Frederic; Guerquin, Marie-Justine; Bonnet, Aline; Bonnin, Marie-Ange; Havis, Emmanuelle; Malbouyres, Maryline; Bidaud, Christelle Bonod; Maro, Geraldine; Gilardi-Hebenstreit, Pascale; Rossert, Jerome; Ruggiero, Florence; Duprez, Delphine

2011-01-01

395

EGR1 and EGR2 involvement in vertebrate tendon differentiation.  

PubMed

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

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

2010-12-20

396

The Relationship between Meniscal Tears and Meniscal Position  

PubMed Central

Objective: To investigate how different types of meniscal tears predispose to different patterns of meniscal position in subjects with and without symptomatic knee osteoarthritis (OA). Methods: A cross-sectional analysis of 161 women participating in an observational study to evaluate knee OA progression was performed using baseline MRI data. Meniscal morphologic features were scored in three separate locations. Meniscal position measures were determined for extrusion and proportion of coverage. Analysis was performed using multiple linear regression models treating each tear type as an individual variable with a binary response. Results: Complex tears, cysts and maceration of the medial meniscus were associated with more medial (p=0.0004, p=0.004, p <0.0001, respectively) and anterior extrusion (p =0.03, p=0.03, p<0.0001, respectively) than normal menisci. Horizontal tears of the lateral meniscus had more lateral (p=0.005) and anterior extrusion (p<0.0001) than normal menisci. Anterior and body tears of the medial meniscus were associated with more anterior extrusion (p=0.0006, p=0.01, respectively), whereas meniscal body tears alone had more medial extrusion than normal menisci (p= 0.0002). Meniscal body tears of the lateral meniscus had more lateral extrusion than normal menisci (p=0.01). Conclusion: Anterior horn and meniscal body tears and the more severe macerated and complex tear types predisposed to more medial meniscal extrusion. Laterally, only meniscal body and horizontal tears significantly affected extrusion, potentially reflecting a lower overall prevalence of lateral meniscal tears. These results may have important implications in identifying tear types associated with more meniscal dysfunction, with the ultimate goal of identifying those at greatest risk for knee OA progression.

Allen, Deborah M.; Li, Ling; Crema, Michel D.; Marra, Monica D.; Guermazi, Ali; Wyman, Brad T.; Le Graverand, Marie-Pierre Hellio; Englund, Martin; Brandt, Kenneth D.; Hunter, David J.

2010-01-01

397

Sphincter tears in primiparous women: is age a factor?  

Microsoft Academic Search

Anal sphincter tears during vaginal delivery may result in serious sequelae. We examined whether younger primiparous patients\\u000a were at increased risk for sphincter tears during vaginal delivery. Data from an obstetric automated record were analyzed.\\u000a Primiparous women delivering term infants (n?=?5,937) were included to test for an association between age and sphincter tear rates. Three age groups were considered:\\u000a young

C. Bryce Bowling; Thomas L. Wheeler II; Kimberly A. Gerten; Victoria R. Chapman; Kathryn L. Burgio; Holly E. Richter

2009-01-01

398

Transtendon arthroscopic repair of partial-thickness, articular surface tears of the supraspinatus: results at 2 years.  

PubMed

Partial-thickness articular tears of the supraspinatus represent a not uncommon event in shoulder pathology, but their treatment remains controversial. We believe that these lesions must be treated with surgical repair: we hereby describe our technique of transtendon arthroscopic repair. We have treated 33 patients with an average age of 53.3 years (range 34-69). The average follow-up was 33 months (range 26-45). The post-operative Constant score values have shown a total increase of 48.2 points (from preoperative 44.4 points to post-operative 91.6 points). In the MRI follow-up assessment no cases of retears have occurred. The use of this technique enables the reconstitution of the tendon with complete reconstruction of its footprint without damaging its intact part. We believe that this can allow a better recovery. PMID:19711170

Castricini, R; Panfoli, N; Nittoli, R; Spurio, S; Pirani, O

2009-04-01

399

Tear proteins in health, disease, and contact lens wear.  

PubMed

Although well known as manifestations of sorrow, emotions, frustration, and blackmail, tears have a more prosaic and important function as a lubricant and as a blood substitute for the cornea. Tears transport oxygen and carbon dioxide and play a central role in the cellular economy of the ocular surface and conjunctiva. In addition to proteins, tears contain lipids and glycoproteins, which increase the wetting effect of the aqueous component and delay evaporation. The total protein concentration of tears is about 10% of that of the plasma. About 80 proteins and polypeptide components have been detected by electrophoresis. Among 30 proteins identified in tears, about 50% are enzymes. Some of the tear enzymes are secreted by the lacrimal glands; others are produced by or released from epithelial cells of the cornea and the conjunctiva. Finally, a few enzymes originate from plasma and appear in tears only in cases with increased permeability of the conjunctival vessels. The aim of this review is to provide clinical and biochemical information about tear enzymes both for ophthalmologists and for biochemists interested in clinical and experimental tear enzymology. PMID:18457567

Sariri, R; Ghafoori, H

2008-04-01

400

Foot posture is associated with morphometry of the peroneus longus muscle, tibialis anterior tendon, and Achilles tendon.  

PubMed

The aim of this study was to investigate the association between foot type and the morphometry of selected muscles and tendons of the lower limb. Sixty-one healthy participants (31 male, 30 female; aged 27.1?±?8.8 years) underwent gray-scale musculoskeletal ultrasound examination to determine the anterior-posterior (AP) thickness of tibialis anterior, tibialis posterior, and peroneus longus muscles and tendons as well as the Achilles tendon. Foot type was classified based on arch height and footprint measurements. Potentially confounding variables (height, weight, hip and waist circumference, rearfoot and ankle joint range of motion, and levels of physical activity) were also measured. Multiple linear regression models were used to determine the association between foot type with muscle and tendon morphometry accounting for potentially confounding variables. Foot type was significantly and independently associated with AP thickness of the tibialis anterior tendon, peroneus longus muscle, and Achilles tendon, accounting for approximately 7% to 16% of the variation. Flat-arched feet were associated with a thicker tibialis anterior tendon, a thicker peroneus longus muscle, and a thinner Achilles tendon. Foot type is associated with morphometry of tendons that control sagittal plane motion of the rearfoot; and the peroneus longus muscle that controls frontal plane motion of the rearfoot. These findings may be related to differences in tendon loading during gait. PMID:23301865

Murley, G S; Tan, J M; Edwards, R M; De Luca, J; Munteanu, S E; Cook, J L

2013-01-10

401

Asynchronous Muscle and Tendon Adaptation After Surgical Tensioning Procedures  

PubMed Central

Background: Donor muscles are often highly stretched in tendon transfer surgery. Despite literature reports that showed adaptation of the serial sarcomere number to moderate stretch, little is known regarding adaptation to stretch outside of the physiological range (commonly seen in clinical tendon transfer). This study was performed to evaluate muscle-tendon-unit adaptation to tendon transfer surgery in an animal model. Methods: Thirty-seven male New Zealand White rabbits were used for muscle analysis, and twenty-five of those rabbits were also used for biological analysis of the tendons after the experiment. The extensor digitorum muscle of the second toe was transferred at a specific sarcomere length of 3.7 ?m, chosen to be near the end of the descending limb of the rabbit sarcomere length-tension curve. Animals were killed at five time points, at which complete muscle architectural analysis as well as measurements of tendon dimension, tendon water content, and tendon cytokine transcript levels were performed. Results: As expected, a rapid increase in the serial sarcomere number (mean and standard error of the mean, 4658 ± 154 in the transferred muscle compared with 3609 ± 80 in the control muscle) was found one week after the surgery. From this time point until eight weeks, this increased serial sarcomere number paradoxically decreased, while the sarcomere length remained constant. Eventually, at eight weeks, it reached the same value (3749 ± 83) as that in the control muscle (3767 ± 61). Tendon adaptation was delayed relative to muscle adaptation, but it was no less dramatic. Tendon length increased by 1.43 ± 0.74 mm over the eight-week time period, corresponding to a strain of 15.55% ± 4.08%. Conclusions: To our knowledge, this is the first report of biphasic adaptation of the serial sarcomere number followed by tendon adaptation, and it indicates that muscle adapts more quickly than tendon does. Taken together, these results illustrate a complex and unique interaction between muscles and tendons that occurs during adaptation to stretching during tendon transfer. Clinical Relevance: Understanding the time course of muscle-tendon-unit adaptation can provide surgeons with information to guide postoperative care following tendon transfers as well as guidelines for tensioning muscles during tendon transfer.

Takahashi, Mitsuhiko; Ward, Samuel R.; Marchuk, Linda L.; Frank, Cyril B.; Lieber, Richard L.

2010-01-01

402

Patellar tendon ossification after anterior cruciate ligament reconstruction using bone - patellar tendon - bone autograft  

PubMed Central

Background Among the various complications described in literature, the patellar tendon ossification is an uncommon occurrence in anterior cruciate ligament (ACL) reconstruction using bone – patellar tendon – bone graft (BPTB). The heterotopic ossification is linked to knee traumatism, intramedullary nailing of the tibia and after partial patellectomy, but only two cases of this event linked to ACL surgery have been reported in literature. Case presentation We present a case of a 42-year-old Caucasian man affected by symptomatic extended heterotopic ossification of patellar tendon after 20 months from ACL reconstruction using BPTB. The clinical diagnosis was confirmed by Ultrasound, X-Ray and Computed Tomography studies, blood tests were performed to exclude metabolic diseases then the surgical removal of the lesion was performed. After three years from surgery, the patient did not report femoro-patellar pain, there was not range of motion limitation and the clinical-radiological examinations resulted negative. Conclusion The surgical removal of the ossifications followed by anti-inflammatory therapy, seems to be useful in order to relieve pain and to prevent relapses. Moreover, a thorough cleaning of the patellar tendon may reveal useful, in order to prevent bone fragments remain inside it and to reduce patellar tendon heterotopic ossification risk.

2013-01-01

403

[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

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

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

2008-11-13

404

Rupture of the Achilles and patellar tendons.  

PubMed

Certain similarities can clearly be appreciated between Achilles and patellar tendon ruptures. Both are strong tendons that transmit force bridging at least one joint of the lower limb. When healthy, both require massive forces to be disrupted, and both can be weakened through certain systemic disease processes, steroids, and fluoroquinones. Both allow for a variety of innovative management possibilities that ultimately lend themselves to individual surgical preference. We feel that, although surgical management plays an important role in restoring continuity in knee extension and in plantar flexion, functional outcome inevitably relies on patient motivation and a well-established physiotherapy regime. Sports physicians should be able to identify both conditions early in their presentation, but still hold a high index of suspicion for these problems in athletes who have an acute exacerbation of ongoing tendinopathy. PMID:14560546

Maffulli, Nicola; Wong, Jason

2003-10-01

405

Increasing incidence of Achilles tendon rupture.  

PubMed

During the period 1987-91, 153 cases of total Achilles tendon rupture were diagnosed in the city of Malmo (population 230,000). Almost two thirds were caused by sporting activities, notably badminton. Ruptures caused by nonsports injuries were found in older subjects. Compared to the age-specific incidence in 1950-73, a marked increase in both sports and nonsports injuries was found and patients in the latter group were older than in the former period. Patients with Achilles tendon ruptures can be classified into two subgroups with partly different etiologies: young or middle-aged athletes and older non-athletic persons. The increase in the former group is mostly explained by increased participation in recreational sports; the cause of increase in the latter group is unknown. PMID:8948254

Möller, A; Astron, M; Westlin, N

1996-10-01

406

77 FR 69508 - Inservice Inspection of Prestressed Concrete Containment Structures With Grouted Tendons  

Federal Register 2010, 2011, 2012, 2013

...of Prestressed Concrete Containment Structures With Grouted Tendons AGENCY: Nuclear...of Prestressed Concrete Containment Structures with Grouted Tendons.'' This guide...for prestressed concrete containment structures with grouted tendons. ADDRESSES:...

2012-11-19

407

Tibialis Anterior Tendon Transfer after Clubfoot Surgery  

Microsoft Academic Search

Recurrent dynamic and structural deformities following clubfoot surgery are commonly due to residual muscle imbalance from\\u000a a strong tibialis anterior muscle and weak antagonists. We asked whether subcutaneous tibialis anterior tendon transfer effectively\\u000a treated recurrent deformities following clubfoot surgery and whether the presence of structural deformities influenced the\\u000a outcome. The patients were divided into two groups: Group I, dynamic supination

George H. Thompson; Harry A. Hoyen; Tracey Barthel

2009-01-01

408

Fatigue rupture of wallaby tail tendons.  

PubMed

Wallaby tail tendons fail after repeated application of stresses much lower than would be needed to break them in a single pull. We show that this a fatigue phenomenon, distinct from the creep rupture that occurs after prolonged application of a constant stress. The two phenomena are disctinguished by experiments in which tensile stress is cycled at different frequencies, ranging from 1 to 50 Hz. PMID:9244805

Wang, X T; Ker, R F; Alexander, R M

1995-03-01

409

[What's new after an ACL tear?].  

PubMed

Following a severe knee sprain during which the anterior cruciate ligament has been torn, the patient and his doctor are facing the choice between a conservative treatment or a surgical approach. Reviewing the international literature allows us to build a pertinent opinion. If the conservative treatment is selected, one must be aware that the proportion of good results does not exceed 50%. This is why, this treatment is only recommended for little demanding and non-sports active persons. In various surgical options, the autologous anterior cruciate ligament reconstruction, using a graft of patellar or hamstrings tendons gives good, reliable and reproducible results. PMID:20822051

Fritschy, Daniel; Richard, Jean-Christophe

2010-08-11

410

Microstructure analysis of calcium phosphate formed in tendon  

Microsoft Academic Search

The surface of soft tendon tissue has been modified using calcium phosphate in order for the tendon to directly connect with hard bone and reconstruct an injured ligament. Calcium phosphate was coated onto the tendon in a soaking process using alternating a CaCl2 (200 mM) and a Na2HPO4 (120 mM) solution. According to SEM\\/EDX observations, calcium phosphate was formed, not

I. Yamaguchi; T. Kogure; M. Sakane; S. Tanaka; A. Osaka; J. Tanaka

2003-01-01

411

Dynamic viscoelastic behavior of lower extremity tendons during simulated running  

Microsoft Academic Search

De Zee, M., F. Bojsen-Møller, and M. Voigt. Dynamic viscoelastic behavior of lower extremity tendons during sim- ulated running. J Appl Physiol 89: 1352-1359, 2000.—The aim of this project was to see whether the tendon would show creep during long-term dynamic loading (here referred to as dynamic creep). Pig tendons were loaded by a material- testing machine with a human

M. DE ZEE; F. BOJSEN-MØLLER; M. VOIGT

412

Tenocyte contraction induces crimp formation in tendon-like tissue  

Microsoft Academic Search

Tendons are composed of longitudinally aligned collagen fibrils arranged in bundles with an undulating pattern, called crimp.\\u000a The crimp structure is established during embryonic development and plays a vital role in the mechanical behaviour of tendon,\\u000a acting as a shock-absorber during loading. However, the mechanism of crimp formation is unknown, partly because of the difficulties\\u000a of studying tendon development in

Andreas Herchenhan; Nicholas S. Kalson; David F. Holmes; Patrick Hill; Karl E. Kadler; Lee Margetts

413

Gender differences in the viscoelastic properties of tendon structures  

Microsoft Academic Search

.   The purpose of this study was to investigate the differences in the viscoelastic properties of human tendon structures (tendon\\u000a and aponeurosis) in the medial gastrocnemius muscle between men (n=16) and women (n=13). The elongation of the tendon and aponeurosis of the medial gastrocnemius muscle was measured directly by ultrasonography,\\u000a while the subjects performed ramp isometric plantar flexion up to

Keitaro Kubo; Hiroaki Kanehisa; Tetsuo Fukunaga

2003-01-01

414

Human wrist motors: Biomechanical design and application to tendon transfers  

Microsoft Academic Search

Moment arm, muscle architecture, and tendon compliance in cadaveric human forearms were determined and used to model the wrist torque-joint angle relation (i.e. wrist torque profile). Instantaneous moment arms were calculated by differentiating tendon excursion with respect to joint rotation. Maximum isometric tension of each wrist muscle-tendon unit was predicted based on muscle physiological cross-sectional area. Muscle forces were subsequently

G. J. Loren; S. D. Shoemaker; T. J. Burkholder; M. D. Jacobson; J. Fridén; R. L. Lieber

1996-01-01

415

Bilateral spontaneous rupture of Achilles tendons: a case report.  

PubMed

Spontaneous bilateral rupture of Achilles tendon is rare. Rupture of the Achilles tendon has been described in patients on oral corticosteroid therapy. The sudden dorsiflexion of the plantar-flexed foot is the usual mechanism of injury. Spontaneous bilateral rupture is common in the degenerated tendon, which is often seen in patients with long-term corticosteroid therapy. This case is unusual because the patient has never taken steroids. We discuss the mechanism of injury and other probable causes. PMID:16131683

Rao, S K; Navadgi, B C; Vasdev, A

2005-08-01

416

Biomechanical Analysis of Distal Biceps Tendon Repair Methods  

Microsoft Academic Search

Background: The 1-incision and 2-incision techniques are commonly used methods to repair a distal biceps rupture, and they differ in the location of reinsertion of tendon into bone.Hypothesis: The native distal biceps brachii tendon inserts on the posterior-ulnar aspect of the bicipital tuberosity, which functions as a cam, increasing the tendon's moment arm during its principal action of forearm supination.

Jon Henry; Jeff Feinblatt; Christopher C. Kaeding; James Latshaw; Alan Litsky; Roman Sibel; Julie A. Stephens; Grant L. Jones

2007-01-01

417

Repair of a complete anterior cruciate tear using prolotherapy: a case report  

PubMed Central

Objective and Importance Surgical reconstruction is considered definitive treatment for anterior cruciate ligament (ACL) tears but precise surgical indications are debated. Some patients are reluctant or inappropriate surgical candidates. Prolotherapy is a non-surgical injection therapy for chronic musculoskeletal pain and instability. This case report documents the non-surgical repair of a torn ACL using prolotherapy and at-home exercise. Clinical Presentation and Intervention The 18 year old female patient sustained a right knee injury during a downhill skiing accident. Magnetic Resonance Imaging (MRI) revealed a high-grade partial versus complete rupture; Lachman exam findings suggested a complete rupture. She deferred surgical treatment. At 21 weeks post-injury, with unstable gait, inability to climb stairs and more than 1 cm anterior drawer test, she consented to undergo prolotherapy injections. She received 7 prolotherapy sessions over a 15 week period. At-home exercises were initiated at the 3rd prolotherapy session. Results The patient improved. Walking on flat ground improved 4 weeks after initiation of prolotherapy; she could ride a stationary bicycle for 30 minutes by 12 weeks. By 15 weeks, the patient had no instability climbing and descending stairs, the anterior drawer test was negative and MRI showed an intact ACL with fibrosis. Subsequently, she returned to full sport activity. Conclusions We document the non-surgical repair of a high-grade partial or complete ACL tear using prolotherapy and at-home exercise. Prolotherapy may be an alternative to surgery in carefully selected patients. This report is consistent with findings of recent pilot-level studies and suggests the need for rigorous clinical trials assessing prolotherapy as treatment for ligament and tendon injury in selected patients.

Grote, Walter; Delucia, Rosa; Waxman, Robert; Zgierska, Aleksandra; Wilson, John; Rabago, David

2010-01-01

418

Repair of a complete anterior cruciate tear using prolotherapy: a case report.  

PubMed

OBJECTIVE AND IMPORTANCE: Surgical reconstruction is considered definitive treatment for anterior cruciate ligament (ACL) tears but precise surgical indications are debated. Some patients are reluctant or inappropriate surgical candidates. Prolotherapy is a non-surgical injection therapy for chronic musculoskeletal pain and instability. This case report documents the non-surgical repair of a torn ACL using prolotherapy and at-home exercise. CLINICAL PRESENTATION AND INTERVENTION: The 18 year old female patient sustained a right knee injury during a downhill skiing accident. Magnetic Resonance Imaging (MRI) revealed a high-grade partial versus complete rupture; Lachman exam findings suggested a complete rupture. She deferred surgical treatment. At 21 weeks post-injury, with unstable gait, inability to climb stairs and more than 1 cm anterior drawer test, she consented to undergo prolotherapy injections. She received 7 prolotherapy sessions over a 15 week period. At-home exercises were initiated at the 3(rd) prolotherapy session. RESULTS: The patient improved. Walking on flat ground improved 4 weeks after initiation of prolotherapy; she could ride a stationary bicycle for 30 minutes by 12 weeks. By 15 weeks, the patient had no instability climbing and descending stairs, the anterior drawer test was negative and MRI showed an intact ACL with fibrosis. Subsequently, she returned to full sport activity. CONCLUSIONS: We document the non-surgical repair of a high-grade partial or complete ACL tear using prolotherapy and at-home exercise. Prolotherapy may be an alternative to surgery in carefully selected patients. This report is consistent with findings of recent pilot-level studies and suggests the need for rigorous clinical trials assessing prolotherapy as treatment for ligament and tendon injury in selected patients. PMID:20802815

Grote, Walter; Delucia, Rosa; Waxman, Robert; Zgierska, Aleksandra; Wilson, John; Rabago, David

2009-12-01

419

Retropharyngeal Calcific Tendonitis Mimics a Retropharyngeal Abscess  

PubMed Central

Retropharyngeal calcific tendonitis (RCT) is an uncommon, self-limiting condition that is often omitted in the differential diagnosis of a retropharyngeal fluid collection. This condition mimics a retropharyngeal abscess and should be considered when evaluating a fluid collection in the retropharyngeal space. Although calcific tendonitis at other sites has been well described in the medical literature, it appears that this entity has been underreported in the otolaryngology literature where only a few case reports have been identified. Presumably, the actual incidence is higher than the reported incidence, due to lack of familiarity with this disorder. As an otolaryngologist's scope of practice includes the managements of retropharyngeal lesions, it is important for the otolaryngologist to recognize the presentation of acute RCT and be familiar with appropriate treatment strategies. Retropharyngeal calcific tendonitis presents with neck pain, limitation of neck range of motion and includes inflammation, calcifications, and a sterile effusion within the longus colli muscle. Treatment is medical with nonsteroidal anti-inflammatory medications. RCT does not require surgical treatment, and an accurate diagnosis can prevent unnecessary attempts at operative drainage. In this study, we discuss two cases of RCT, summarize the salient features in diagnosis, including key radiologic features, discuss treatment options, and review the literature.

Wexler, Sonya

2013-01-01

420

Complications of distal biceps tendon repairs.  

PubMed

Surgical repair is the most reliable method of restoring flexion and supination strength of the elbow and forearm after acute rupture of the distal biceps tendon. Although there may be small measurable deficits in power, endurance, and terminal forearm rotation when carefully evaluated, most of the patients regain near normal upper extremity motion and function and can return to preinjury activities. There are currently 2 basic surgical approaches for distal biceps tendon repair, using 1 anterior incision or using 1 anterior and 1 lateral incision. Anterior repair alone has the advantage of a minimal risk of heterotopic bone formation, but carries a greater chance of injury to the posterior interosseous nerve. In turn, the 2-incision technique markedly diminishes the risk of radial nerve palsy, but is associated with a greater likelihood of heterotopic bone formation limiting forearm rotation. Rerupture of the distal biceps tendon after repair is uncommon with either technique, and the risk of all complications seems to increase with a delay in surgical intervention after rupture. When motion limiting heterotopic ossification does occur, surgical resection can proceed when the process becomes mature as defined by plain radiographs. Fortunately, functional forearm motion can be commonly restored in these cases with careful attention to surgical details and postoperative rehabilitation. PMID:18703974

Cohen, Mark S

2008-09-01

421

Low level laser therapy in healing tendon  

NASA Astrophysics Data System (ADS)

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.

Carvalho, P. T. C.; Batista, Cheila O. C.; Fabíola, C.

2005-11-01

422

Ligamentation of the adductor hallucis tendon in bunionectomy.  

PubMed

Several techniques are available for the correction of hallux abducto valgus, but none of them provide a direct and mechanically sound attachment to the lateral aspect of the first metatarsal head. The author describes adductor hallucis tendon ligamentation, a technique that produces direct stability between the first and second metatarsals. This stability is achieved by transferring the adductor hallucis tendon. The tendon is attached to the distal aspects of the first and second metatarsals. Adductor hallucis tendon ligamentation is a dependable option in the correction of hallux abducto valgus, providing an excellent outcome with good long-term results. PMID:12381801

Shrum, Dale G

2002-10-01

423

Conservative management of rotator cuff tear.  

PubMed

Ranking among the most prevalent of shoulder disorders, lesions involving shoulder rotator cuff strike million of patients in the United States at different points in their lives. Despite the fact that rotator cuff disease is a very common cause of pain and disability of the upper arm, a high proportion of patients is asymptomatic and unaware of performing daily living activities despite of a shoulder lesion. Given these drawbacks, surgeons are trying exploring whether conservative treatment is a viable option for the management of these injuries. This study presents a rationale to consider nonoperative treatment an effective option when dealing with patients with rotator cuff tears. PMID:22089284

Pegreffi, Francesco; Paladini, Paolo; Campi, Fabrizio; Porcellini, Giuseppe

2011-12-01

424

Nonlinear growth of strongly unstable tearing modes  

SciTech Connect

Rutherford`s theory of the tearing instability is extended to cases where current nonlinearities are important, such as long wavelength modes in current slabs and the m = 1 instability in tokamaks with moderately large aspect-ratios. Of particular interest is the possibility that the associated magnetic islands, as a result of secondary instabilities, have a singular response to the Ohmic diffusion of the current. A family of islands is used to test this possibility; it is found that the response remains bounded.

Waelbroeck, F.L.

1993-11-01

425

Triangular fibrocartilage complex tears: a review.  

PubMed

Triangular fibrocartilage complex (TFCC) tears are a common source of ulnar sided wrist pain. Originally described by Palmer, in 1981, as a complex of several structures, our understanding of the anatomy and the function of the TFCC has been refined by histologic studies. The TFCC plays an important role in load bearing across the wrist as well as in distal radioulnar joint (DRUJ) stabilization. A thorough knowledge of the anatomy as well as the Palmer classification system helps to guide treatment options. PMID:17155920

Ahn, Anthony K; Chang, David; Plate, Ann-Marie