Science.gov

Sample records for flexion knee deformity

  1. Femoral shortening in correction of congenital knee flexion deformity with popliteal webbing.

    PubMed

    Saleh, M; Gibson, M F; Sharrard, W J

    1989-01-01

    Severe knee flexion deformity with popliteal webbing or pterygium is considered to be uncorrectable. The soft tissues and, in particular, the main nerves and vessels are short relative to the bone. Femoral shortening was used in correction of such a deformity in a child with arthrogryposis. The operative procedure is described. Femoral shortening should be considered as an aid to correction of any severe knee flexion deformity.

  2. Successful Correction of Idiopathic Bilateral Flexion Deformity of Knee: A Rare Case Report

    PubMed Central

    Mugalur, Aakash; Pathak, Aditya C; Shahane, Sunil M; Samant, Ashwin

    2015-01-01

    Introduction: Bilateral Flexion Deformity commonly results secondary to cerebral palsy, poliomyelitis, haemophilia etc. It is accompanied by valgus deformity and external rotation at knee in long standing cases secondary to the contracture of the iliotibial tract. Flexion deformity at knees is an impediment to the normal ambulation and is difficult to address. Case Report: A 34 year old male presented with bilateral knee stiffness. He had multifocal tuberculosis and was bed ridden for almost a year and consequently developed bilateral knee flexion deformity of 60o with further flexion upto 120o. Patient was treated with gradual distraction using a modified external fixator and achieved full correction at the end of 6 weeks. At final followup patient was walking comfortably and was able to squat and sit crossed legged. Conclusion: Idiopathic isolated bilateral flexion deformity of knees is very rare and is an impediment to normal ambulation. Arthrodiastasis with indigenously designed fixator using the Ilizarov principle and modified fixator is a simple, efficient and cost effective treatment for flexion deformity of knee. PMID:27299020

  3. Severe Bilateral Fixed Flexion Deformity-Simultaneous or Staged Total Knee Arthroplasty?

    PubMed

    Lee, Wu Chean; Kwan, Yu Heng; Yeo, Seng Jin

    2016-01-01

    Outcomes of 29 simultaneous (SimBTKA) and 38 staged bilateral total knee arthroplasty (StaBTKA) subjects with severe (≥16°) bilateral fixed flexion deformity (FFD) were retrospectively investigated. SimBTKA patients were significantly younger (63 ± 8 vs 68 ± 7, P > .01). At 2 years, SimBTKA subjects had significantly better residual FFD (2.5° ± 5.1° vs 5.4° ± 6.6°, P = .02) and Knee Society function score (75.7 ± 25.7 vs 69.3 ± 24.1, P = .02). However, Knee Society knee scores, Oxford Knee Scores, and Short Form-36 scores were similar. These suggest no large clinical advantage of SimBTKA over StaBTKA. We feel that severe bilateral FFD is not an absolute indication for SimBTKA.

  4. Global analysis of sagittal spinal alignment in major deformities: correlation between lack of lumbar lordosis and flexion of the knee.

    PubMed

    Obeid, Ibrahim; Hauger, Olivier; Aunoble, Stéphane; Bourghli, Anouar; Pellet, Nicolas; Vital, Jean-Marc

    2011-09-01

    It has become well recognised that sagittal balance of the spine is the result of an interaction between the spine and the pelvis. Knee flexion is considered to be the last compensatory mechanism in case of sagittal imbalance, but only few studies have insisted on the relationship between spino-pelvic parameters and lower extremity parameters. Correlation between the lack of lumbar lordosis and knee flexion has not yet been established. A retrospective study was carried out on 28 patients with major spinal deformities. The EOS system was used to measure spinal and pelvic parameters and the knee flexion angle; the lack of lumbar lordosis was calculated after prediction of lumbar lordosis with two different formulas. Correlation analysis between the different measured parameters was performed. Lumbar lordosis correlated with sacral slope (r = -0.71) and moderately with knee flexion angle (r = 0.42). Pelvic tilt correlated moderately with knee flexion angle (r = 0.55). Lack of lumbar lordosis correlated best with knee flexion angle (r = 0.72 and r = 0.63 using the two formulas, respectively). Knee flexion as a compensatory mechanism to sagittal imbalance was well correlated to the lack of lordosis and, depending on the importance of the former parameter, the best procedure to correct sagittal imbalance could be chosen.

  5. Posterior cruciate-substituting total knee replacement recovers the flexion arc faster in the early postoperative period in knees with high varus deformity: a prospective randomized study.

    PubMed

    Öztürk, Alpaslan; Akalın, Yavuz; Çevik, Nazan; Otuzbir, Ali; Özkan, Yüksel; Dostabakan, Yasin

    2016-07-01

    Posterior cruciate retention (CR) and substitution (PS) has been controversial in knee replacement surgery. Satisfactory medium and long-term results have been reported in knees with and without deformity but there are limited studies about early functional comparison in terms of recovery of flexion arc, stair activity, walking ability and straight leg raising, especially, in early postoperative period in knees with deformity. Therefore, we aimed to compare the flexion arc in CR and PS knees in postoperative first year including early postoperative days prospectively. Consecutive patients with a deformity of >10° were included and allocated to CR and PS groups randomly. KSS and Feller-patella scores were recorded both preoperatively and postoperatively (1st, 2nd, 3rd and 12th months). Flexion and extension were measured both preoperatively and postoperatively (1st, 2nd, 3rd day and discharge day as well as 1st, 2nd, 3rd and 12th months). Visual analog scale (VAS) was recorded postoperatively at the 1st, 2nd, 3rd and discharge day and at 1st, 2nd, 3rd and 12th months. The walking ability, stair activity and straight leg raising were recorded. Patients were also examined at the last visit with minimum 7-year follow-up with KSS, Feller-patella and VAS scores. Their mean flexion arcs were measured and recorded. There were 61 TKR evaluated. KSS knee and function scores at the 3rd month and KSS Knee Score at 1st year were superior in PS knees (p = 0.029, p = 0.046, p = 0.026). Flexion arc was found larger on day 1, 2, 3 and discharge day, and at 1st, 2nd, 3rd and 12th month in PS group (p = 0.048, p = 0.002, p = 0.027, p = 0.043, p = 0.014, p = 0.003, p = 0.002, p = 0.018). Walking and stair activity showed no difference but straight leg raising was better in CR knees (p = 0.02). Mean flexion arc was larger in PS knees at the last visit after 7 years (119.0° ± 7.5° in PS and 113.8° ± 8.7° in CR, p = 0.02). There was no revision

  6. Total Knee Arthroplasty for Severe Flexion Contracture in Rheumatoid Arthritis Knees

    PubMed Central

    Hwang, Youn Soo; Moon, Kyu Pill; Kim, Kyung Taek; Kim, Jin Wan; Park, Won Seok

    2016-01-01

    Flexion contracture deformities, as well as severe varus and valgus deformities of the knee joint, accompany osteoarthritis or rheumatoid arthritis (RA). In particular, severe flexion contracture deformity of the knee joint is often found in patients with RA, which renders them nonambulatory. This report describes a 26-year-old female patient diagnosed with RA 10 years ago. She had chronic joint pain, severe flexion contracture, valgus deformity in both knees, and limited range of motion in both knees and became nonambulatory. She underwent a total knee arthroplasty (TKA) and serial casting and physical therapy to restore stable joint movement and correct knee joint deformity. Her pain was successfully relieved, and she was able to walk after surgery. Here, we report the excellent results of TKA in this RA patient with severe flexion contracture of both knees. PMID:27894181

  7. Effect of implant design on knee flexion.

    PubMed

    Dennis, Douglas A; Heekin, R David; Clark, Charles R; Murphy, Jeffrey A; O'Dell, Tammy L; Dwyer, Kimberly A

    2013-03-01

    From March 2006 to August 2008, 93 subjects (186 knees) underwent simultaneous bilateral total knee arthroplasty performed by eight surgeons at North American centers. This randomized study was conducted to determine whether non-weight-bearing passive flexion was superior for knees receiving a posterior stabilized high flexion device compared to a posterior stabilized standard device in the contra-lateral knee. Weight-bearing single leg active flexion was one secondary endpoint. Follow-up compliance was 92.5%. Results show small, but significant superiority in the motion metrics for the high flexion device compared to the standard device 12 months after surgery, especially for a subgroup of patients with pre-operative flexion less than 120° in both knees. Thus, the ideal candidate for the high flexion device may be one with lesser pre-operative flexion.

  8. [Management of Flexion Contracture in Primary Total Knee Arthroplasty].

    PubMed

    Hube, R; Mayr, H O; Pfitzner, T; von Roth, P

    2015-06-01

    Flexion contracture is a common deformity of the arthritic knee. The present publication describes causes, clinical relevance and surgical technique in the presence of flexion contractures in total knee arthroplasty. Flexion contracture can be attributed to different causes. Basically it is a mismatch between flexion and extension gaps. Moderate and severe deformities have to be corrected by additional surgical interventions. In most cases soft tissue techniques with release of contracted structures, the removal of osteophytes and additional distal femoral bone resection are necessary. The goal of these interventions is to achieve full extension of the knee. During rehabilitation attention has to be paid to maintain it with intensive physical therapy. A remaining flexion contracture is associated with inferior functional outcome and persistent pain.

  9. Measured flexion following total knee arthroplasty.

    PubMed

    Mai, Kenny T; Verioti, Christopher A; Hardwick, Mary E; Ezzet, Kace A; Copp, Steven N; Colwell, Clifford W

    2012-10-01

    Postoperative flexion is an important factor in the outcome of total knee arthroplasty. Although normal activities of daily living require a minimum of 105° to 110° of flexion, patients from non-Western cultures often engage in activities such as kneeling and squatting that require higher flexion. The desire to achieve greater flexion serves as the driving force for prosthetic modifications, including high-flexion designs. Techniques used to measure knee flexion and knee position during measurement are not often described or are different depending on the examiner. The purpose of this study was to compare active (self) and passive (assisted) flexion after successful total knee arthroplasty for 5 prostheses (2 standard and 3 high-flexion) using clinical (goniometer) and radiographic (true lateral radiograph) measurement techniques by different independent examiners.At a mean follow-up of 2.7 years (range, 1-5.6 years), a total of 108 patients (144 total knee arthroplasties) had completed the study. Mean postoperative active flexion was 111° clinically and 109° radiographically for the standard designs and 114° clinically and 117° radiographically for the high-flexion designs. Adding passive flexion increased flexion to 115° clinically and 117° radiographically for the standard designs and 119° clinically and 124° radiographically for the high-flexion designs. Flexion differences between the 2 measurement techniques (active vs passive and clinically vs radiographically) were statistically significant (P<.05). These findings demonstrate the importance of describing how flexion is measured in studies and understanding how the method of measurement can affect the findings.

  10. Anterior distal femoral stapling for correcting knee flexion contracture in children with arthrogryposis--preliminary results.

    PubMed

    Palocaren, Thomas; Thabet, Ahmed M; Rogers, Kenneth; Holmes, Laurens; Donohoe, Maureen; King, Marilyn Marnie; Kumar, Shanmuga Jay

    2010-03-01

    Fixed flexion contractures of the knee are more common and disabling than extension contractures in children with arthrogryposis. For correcting these deformities, there are various surgical options such as soft tissue release, distal femoral osteotomy, and frame distraction. We sought in this study to examine the effectiveness of anterior distal femoral stapling using 8-plates for correcting knee flexion contracture in children with arthrogryposis. We retrospectively assessed 16 knees in 10 children using clinical and radiographic measures. To determine the outcome, we assessed the Functional Mobility Scale (FMS) as well. Statistically, a paired t test, independent t test, and Wilcoxon signed-rank test were used to analyze the results. After anterior distal femoral stapling, there was a reduction in the flexion deformity of the knee in children with arthrogryposis, P<0.05. There was an estimated 18-degree correction comparing the mean preoperative flexion deformity and the mean postoperative flexion deformity. This correction was significant in children when the knee flexion deformity was less than 45 degrees. The FMS also improved in those patients where the residual flexion contracture was less than 30 degrees at follow-up, suggesting an improvement in their ambulatory capacity, P<0.05. Among children with arthrogryposis who present with knee flexion contractures, anterior distal femoral stapling with 8-plates improved their flexion deformity and ambulatory capacity. This technique is less invasive than soft tissue releases, distal femoral osteotomy, or frame distraction and is most rewarding in children with arthrogryposis whose flexion contractures is less than 45 degrees.

  11. Total knee arthroplasty treatment of rheumatoid arthritis with severe versus moderate flexion contracture.

    PubMed

    Yan, Denglu; Yang, Jing; Pei, Fuxing

    2013-11-15

    This study aims to explore the technique of soft tissue balance and joint tension maintenance in total knee arthroplasty (TKA) for the rheumatoid arthritis (RA) patients with flexion contracture of the knee. This retrospective study reviewed flexion contracture deformity of RA patients who underwent primary TKA and ligament and soft tissue balancing. Based on the flexion contracture deformity, the remaining 76 patients available for analysis were divided into two groups, i.e., severe flexion group (SF) and moderate flexion group (MF). There were no intraoperative complications in this study. All patients had improved Knee Society Rating System scores and range of motion. The flexion contracture was completely corrected in MF and SF patients. There were no cases of patellar dislocation, but three cases had mild mediolateral instability in severe flexion group. Four knees (two knees in SF versus two knees in MF) had transient peroneal nerve palsy but recovered after conservative therapy. TKA can be performed successfully in the RA knees with severe flexion contracture. It is very important in TKA to maintain the joint stability in the condition of severe flexion contracture deformity of the RA knee.

  12. Total knee arthroplasty treatment of rheumatoid arthritis with severe versus moderate flexion contracture

    PubMed Central

    2013-01-01

    Background This study aims to explore the technique of soft tissue balance and joint tension maintenance in total knee arthroplasty (TKA) for the rheumatoid arthritis (RA) patients with flexion contracture of the knee. Methods This retrospective study reviewed flexion contracture deformity of RA patients who underwent primary TKA and ligament and soft tissue balancing. Based on the flexion contracture deformity, the remaining 76 patients available for analysis were divided into two groups, i.e., severe flexion group (SF) and moderate flexion group (MF). Results There were no intraoperative complications in this study. All patients had improved Knee Society Rating System scores and range of motion. The flexion contracture was completely corrected in MF and SF patients. There were no cases of patellar dislocation, but three cases had mild mediolateral instability in severe flexion group. Four knees (two knees in SF versus two knees in MF) had transient peroneal nerve palsy but recovered after conservative therapy. Conclusions TKA can be performed successfully in the RA knees with severe flexion contracture. It is very important in TKA to maintain the joint stability in the condition of severe flexion contracture deformity of the RA knee. PMID:24229435

  13. Is high flexion following total knee arthroplasty safe?: evaluation of knee joint loads in the patients during maximal flexion.

    PubMed

    Nagura, Takeo; Otani, Toshiro; Suda, Yasunori; Matsumoto, Hideo; Toyama, Yoshiaki

    2005-08-01

    The purpose of this study was to indicate the mechanical loads and the flexion angle at the knee during rise from maximal flexion following total knee arthroplasty (TKA). Twenty three knees were evaluated using skin marker-based motion analysis system during four different activities of daily living. The average maximum flexion was 90 degrees (34 degrees less than passive flexion) and all subjects required support for their weight to rise from maximal flexion. The external moments and the external forces at the knee during the maximal flexion were smaller than those during the stair descending activity. The results indicate that capable flexion angle for the patients following TKA is approximately 90 degrees which has smaller mechanical loads at the knee than the stair descending activity.

  14. Knee flexion contracture in haemophilia: treatment with circular external fixator.

    PubMed

    Balci, H I; Kocaoglu, M; Eralp, L; Bilen, F E

    2014-11-01

    Haemophilia, a bleeding disorder, causes recurrent intra-articular bleeding of the joints result-ing in chronic haemophilic arthropathy with fixed knee flexion deformity. Mid-long-term results (between 2002 and 2006) of deformity correction in haemophilic patients with Ilizarov type circular external fixators were retrospectively evaluated. There were six patients (five haemophilia A and one haemophilia B). The mean age was 14.7 years (range, 8-22 years) at the time of initial surgery. The mean knee flexion contracture was 45 degrees (range, 30-75 degrees). The mean arc of motion was 58.3 degrees (range, 40-100) before the surgery. The mean duration of follow-up was 8 years (range, 5.5-10 years). The mean duration of external fixation was 4.4 months (range, 2.5-10.5 months). Full extension of the knee joint was obtained in all patients in the early postoperative period. No bleeding, neurological or vascular complications were encountered. The mean amount of recurrence in knee flexion contracture was 10 degrees (range, 0-15 degrees). The amount of the correction was significant (P = 0.0012) and the mean arc of motion was 51.6 degrees (range, 25-90 degrees) that show a decrease of 6.7 degrees (P = 0.04) at the end of follow-up. The circular external fixator is an important, safe and less invasive alternative surgical treatment modality with low recurrence rate. Using the external hinges and distraction during the correction has a protective effect on the joint. It requires a team-work consisting of a haematologist, an orthopaedic surgeon and a physical therapist. © 2014 John Wiley & Sons Ltd.

  15. In Vivo Healthy Knee Kinematics during Dynamic Full Flexion

    PubMed Central

    Hamai, Satoshi; Moro-oka, Taka-aki; Dunbar, Nicholas J.; Miura, Hiromasa; Iwamoto, Yukihide; Banks, Scott A.

    2013-01-01

    Healthy knee kinematics during dynamic full flexion were evaluated using 3D-to-2D model registration techniques. Continuous knee motions were recorded during full flexion in a lunge from 85° to 150°. Medial and lateral tibiofemoral contacts and femoral internal-external and varus-valgus rotations were analyzed as a function of knee flexion angle. The medial tibiofemoral contact translated anteroposteriorly, but remained on the center of the medial compartment. On the other hand, the lateral tibiofemoral contact translated posteriorly to the edge of the tibial surface at 150° flexion. The femur exhibited external and valgus rotation relative to the tibia over the entire activity and reached 30° external and 5° valgus rotations at 150° flexion. Kinematics' data during dynamic full flexion may provide important insight as to the designing of high-flexion total knee prostheses. PMID:23509767

  16. In vivo healthy knee kinematics during dynamic full flexion.

    PubMed

    Hamai, Satoshi; Moro-oka, Taka-aki; Dunbar, Nicholas J; Miura, Hiromasa; Iwamoto, Yukihide; Banks, Scott A

    2013-01-01

    Healthy knee kinematics during dynamic full flexion were evaluated using 3D-to-2D model registration techniques. Continuous knee motions were recorded during full flexion in a lunge from 85° to 150°. Medial and lateral tibiofemoral contacts and femoral internal-external and varus-valgus rotations were analyzed as a function of knee flexion angle. The medial tibiofemoral contact translated anteroposteriorly, but remained on the center of the medial compartment. On the other hand, the lateral tibiofemoral contact translated posteriorly to the edge of the tibial surface at 150° flexion. The femur exhibited external and valgus rotation relative to the tibia over the entire activity and reached 30° external and 5° valgus rotations at 150° flexion. Kinematics' data during dynamic full flexion may provide important insight as to the designing of high-flexion total knee prostheses.

  17. Development of a knee joint motion simulator to evaluate deep knee flexion of artificial knee joints.

    PubMed

    Takano, Y; Ueno, M; Kiguchi, K; Ito, J; Mawatari, M; Hotokebuchi, T

    2008-01-01

    A purpose of this study is to examine the effect that quadriceps femoris force gives to rotation angle and joint reaction force of total knee prosthesis during deep knee flexion such as a unique sitting style called 'seiza' in Japanese. For the evaluation, we developed the knee motion simulator which could bend to 180 degrees continually simulating the passive flexion performed by clinicians. A total knee prosthesis, which is a specially-devised posterior stabilized type and capable of flexion up to 180 degrees, was inserted into bone model. And this prosthesis pulled by three kinds of quadriceps femoris forces to perform parameter study. The results obtained in this study were showed the same tendency with those in the past cadaveric experiment. It is suggested that the rotation angle and joint reaction force of total knee prosthesis are affected by shape of prosthesis, a vector of quadriceps femoris force, and bony aliments during deep knee flexion.

  18. Tibiofemoral contact areas and pressures in six high flexion knees

    PubMed Central

    Vizesi, Frank; Bruce, Warwick; Herrmann, Sebastian; Walsh, William R

    2007-01-01

    The tibiofemoral articulating interfaces of six high flexion knee designs were examined using a standard testing protocol developed by Harris et al. [J Biomech 32:951–958 (1999)] to investigate the polyethylene insert contact areas and pressures. A load of 3600 N was applied for 10 s at 0, 30, 60, 90, 110, 135 and 155° of flexion. Contact areas and pressures at the femoral–polyethylene insert interface were measured with a I-scan 4000 system. Up to 110°of flexion, the VANGUARD RP HI-FLEX showed the highest contact area and lowest pressure. At the deep flexion angles, contact area decreased and contact pressure increased significantly in all knees. The NexGen series showed a constant contact area throughout the various flexion angles. In general, all high flexion knees could result in almost point contact in an extremely high range of motion. PMID:18034243

  19. Association of increased knee flexion and patella clunk syndrome after mini-subvastus total knee arthroplasty.

    PubMed

    Schroer, William C; Diesfeld, Paul J; Reedy, Mary E; LeMarr, Angela

    2009-02-01

    This study reviewed 747 consecutive posterior stabilized total knee arthroplasty (TKA) to explain the increased incidence of patella clunk syndrome that occurred when the surgeon switched from a medial parapatellar arthrotomy to a mini-subvastus (MIS) TKA technique. The incidence of patella clunk syndrome increased with increased postoperative knee flexion. Six weeks after surgery, knees that developed patella clunk had a mean flexion of 124 degrees vs 117 degrees for knees that did not develop this syndrome (P = .016). As the MIS approach resulted in increased knee flexion, this approach was indirectly associated with the increased incidence of patella clunk. Knee flexion at 6 weeks postoperatively was 117 degrees for the MIS knees vs 108 degrees for traditional medial parapatellar arthrotomy knees (P < .001). The effect of increased knee flexion achieved with the MIS approach, which resulted in an increase in patella clunk, was mitigated by using a new posterior stabilized femoral component designed to minimize soft tissue entrapment.

  20. Computer-assisted navigation for the assessment of fixed flexion in knee arthroplasty

    PubMed Central

    Gallie, Price A.M.; Davis, Edward T.; Macgroarty, Kelly; Waddell, James P.; Schemitsch, Emil H.

    2010-01-01

    Background Correction of a fixed flexion deformity is an important goal when performing total knee arthroplasty. The purpose of this study was to assess the accuracy of clinical assessment compared with imageless computer navigation in determining the degree of fixed flexion. Methods We performed navigation anatomy registration using 14 cadaver knees. The knees were held in various degrees of flexion with 2 crossed pins. The degree of flexion was first recorded on the computer and then on lateral radiographs. The cadaver knees were draped as they would be for a total knee arthroplasty, and 9 examiners were asked to clinically assess by visual observation the amount of fixed flexion. Three examiners repeated the process 1 week later. Results The mean error from the radiographs in the navigation group was 2.18° (95% confidence interval [CI] 1.23°–3.01°) compared with 5.57° (95%CI 4.86°–6.29°) in the observer group. The navigation was more consistent, with a range of error of −5° to +5.5° compared with −18.5° to +17.5° in the observer group. The observers tended to underestimate the amount of knee flexion (median error −4°), whereas the navigation group was more evenly distributed (median error 0). The highest concordance coefficient was found between navigation and radiography (0.96). The concordance coefficient was 0.88 for the 3 surgeons who repeated the measurements 1 week later (mean error 3.5°, range 15°). Conclusion The use of computer navigation appears to be a more accurate method for assessing the degree of knee flexion, with a reduced range of error compared with clinical assessment. The use of computer-assisted surgery may therefore provide surgeons with the information required to more consistently restore full extension during total knee arthroplasty. PMID:20100412

  1. Trapezoid supracondylar femoral extension osteotomy for knee flexion contractures in patients with haemophilia.

    PubMed

    Mortazavi, S M J; Heidari, P; Esfandiari, H; Motamedi, M

    2008-01-01

    Flexion deformity of the haemophilic knee is a considerable cause of disability and may need to be managed surgically in severe cases. We have used a trapezoid supracondylar femoral extension osteotomy to correct severe knee flexion deformity. Nine severe haemophilic patients with contractures >30 degrees that were unresponsive to conservative measures underwent 11 trapezoid osteotomies. The angle of deformity was measured using anteroposterior and lateral knee X-ray films at maximum extension. Factor levels of 80-100% were achieved before the operation. A trapezoid osteotomy of the distal femur bone was performed using a lateral approach. The frontal plane angular deformity (if any) was corrected at the same time. The osteotomy site was fixed using an Arbeitsgemeinschaft für Osteo synthesefragen (AO) condylar blade plate. Following surgery, the knee was supported by a plaster splint at 20 degrees of flexion. Physiotherapy was started on third postoperative day and continued three times a week. There was no serious complication. The deformities were corrected in all of the patients and the mean range of motion increased form 68.6 degrees to 98.1 degrees . Bleeding episodes decreased in all four knees which had a bleeding score of 3 before surgery. Using the Orthopaedic Advisory Committee of the World Federation of Haemophilia scores, nine good and two fair results were obtained. All patients regained the ability to walk for both short and long distance without any aid, climb the stairs, bath, and use public transportation. Trapezoid supracondylar femoral extension osteotomy should be considered in the surgical management of severe haemophilic flexion deformity of the knee joint.

  2. Dynamic splinting for knee flexion contracture following total knee arthroplasty: a case report.

    PubMed

    Finger, Eric; Willis, F Buck

    2008-12-29

    Total Knee Arthroplasty operations are increasing in frequency, and knee flexion contracture is a common pathology, both pre-existing and post-operative. A 61-year-old male presented with knee flexion contracture following a total knee arthroplasty. Physical therapy alone did not fully reduce the contracture and dynamic splinting was then prescribed for daily low-load, prolonged-duration stretch. After 28 physical therapy sessions, the active range of motion improved from -20 degrees to -12 degrees (stiff knee still lacking full extension), and after eight additional weeks with nightly wear of dynamic splint, the patient regained full knee extension, (active extension improved from -12 degrees to 0 degrees ).

  3. Posterior femoral condylar offset after total knee replacement in the risk of knee flexion contracture.

    PubMed

    Onodera, Tomohiro; Majima, Tokifumi; Nishiike, Osamu; Kasahara, Yasuhiko; Takahashi, Daisuke

    2013-08-01

    The aim of this study was to clarify the risk of knee flexion contracture associated with a posterior femoral condylar offset after total knee replacement (TKR). Radiographs from 100 healthy Japanese volunteers were included in the study. We evaluated femoral component posterior offset in various implants and compared them with the normal Japanese knee. Posterior offset of the femoral condyle is up to a maximum of 4.7 times greater than that of the healthy Japanese knee in all knee implants. Excess posterior offset of the femoral condyle in TKR prostheses may cause knee joint flexion contracture due to the relative shortening of the posterior soft tissue.

  4. Active Flexion in Weight Bearing Better Correlates with Functional Outcomes of Total Knee Arthroplasty than Passive Flexion

    PubMed Central

    Song, Young Dong; Jain, Nimash; Kang, Yeon Gwi; Kim, Tae Yune

    2016-01-01

    Purpose Correlations between maximum flexion and functional outcomes in total knee arthroplasty (TKA) patients are reportedly weak. We investigated whether there are differences between passive maximum flexion in nonweight bearing and other types of maximum flexion and whether the type of maximum flexion correlates with functional outcomes. Materials and Methods A total of 210 patients (359 knees) underwent preoperative evaluation and postoperative follow-up evaluations (6, 12, and 24 months) for the assessment of clinical outcomes including maximum knee flexion. Maximum flexion was measured under five conditions: passive nonweight bearing, passive weight bearing, active nonweight bearing, and active weight bearing with or without arm support. Data were analyzed for relationships between passive maximum flexion in nonweight bearing by Pearson correlation analyses, and a variance comparison between measurement techniques via paired t test. Results We observed substantial differences between passive maximum flexion in nonweight bearing and the other four maximum flexion types. At all time points, passive maximum flexion in nonweight bearing correlated poorly with active maximum flexion in weight bearing with or without arm support. Active maximum flexion in weight bearing better correlated with functional outcomes than the other maximum flexion types. Conclusions Our study suggests active maximum flexion in weight bearing should be reported together with passive maximum flexion in nonweight bearing in research on the knee motion arc after TKA. PMID:27274468

  5. Effect of patellar thickness on knee flexion in total knee arthroplasty: a biomechanical and experimental study.

    PubMed

    Abolghasemian, Mansour; Samiezadeh, Saeid; Sternheim, Amir; Bougherara, Habiba; Barnes, C Lowry; Backstein, David J

    2014-01-01

    A biomechanical computer-based model was developed to simulate the influence of patellar thickness on passive knee flexion after arthroplasty. Using the computer model of a single-radius, PCL-sacrificing knee prosthesis, a range of patella-implant composite thicknesses was simulated. The biomechanical model was then replicated using two cadaveric knees. A patellar-thickness range of 15 mm was applied to each of the knees. Knee flexion was found to decrease exponentially with increased patellar thickness in both the biomechanical and experimental studies. Importantly, this flexion loss followed an exponential pattern with higher patellar thicknesses in both studies. In order to avoid adverse biomechanical and functional consequences, it is recommended to restore patellar thickness to that of the native knee during total knee arthroplasty.

  6. Intraoperative Manipulation for Flexion Contracture During Total Knee Arthroplasty.

    PubMed

    Matsui, Yoshio; Minoda, Yukihide; Fumiaki, Inori; Nakagawa, Sigeru; Okajima, Yoshiaki; Kobayashi, Akio

    2016-11-01

    Joint gap balancing during total knee arthroplasty (TKA) is important for ensuring postoperative joint stability and range of motion. Although the joint gap should be balanced to ensure joint stability, it is not easy to achieve perfect balancing during TKA. In particular, relative extension gap shortening can induce flexion contracture. Intraoperative manipulation is often empirically performed. This study evaluated the tension required for this manipulation and investigated the influence of intraoperative manipulation on the joint gap in cadaveric knees. Total knee arthroplasty was performed in 6 cadaveric knees from whole body cadavers. Flexion contracture was induced using an insert that was 4 mm thicker than the extension gap, and intraoperative manipulation was performed. Study measurements included the changes in the joint gap after manipulation at 6 positions, with the knee bending from extension to 120° flexion, and the manipulation tension that was required to create a 4-mm increase in the gap. The manipulation tension needed to create a 4-mm increase in the extension gap was 303±17 N. The changes in the joint gap after manipulation were 0.4 mm, 0.6 mm, 0.2 mm, -0.2 mm, -0.4 mm, and -0.6 mm at 0°, 30°, 45°, 60°, 90°, and 120° flexion, respectively. Therefore, the joint gap was not significantly changed by the manipulation. Intraoperative manipulation does not resolve flexion contracture. Therefore, if flexion contracture occurs during TKA, treatment with additional bone cutting and soft tissue release is likely more appropriate than manipulation. [Orthopedics. 2016; 39(6):e1070-e1074.].

  7. Peak knee flexion angles during stair descent in TKA patients.

    PubMed

    Bjerke, Joakim; Öhberg, Fredrik; Nilsson, Kjell G; Foss, Olav A; Stensdotter, Ann K

    2014-04-01

    Reduced peak knee flexion during stair descent (PKSD) is demonstrated in subjects with total knee arthroplasty (TKA), but the underlying factors are not well studied. 3D gait patterns during stair descent, peak passive knee flexion (PPKF), quadriceps strength, pain, proprioception, demographics, and anthropometrics were assessed in 23 unilateral TKA-subjects ~19 months post-operatively, and in 23 controls. PKSD, PPKF and quadriceps strength were reduced in the TKA-side, but also in the contralateral side. A multiple regression analysis identified PPKF as the only predictor (57%) to explain the relationship with PKSD. PPKF was, however sufficient for normal PKSD. Deficits in quadriceps strength in TKA-group suggest that strength is also contributing to smaller PKSD. Increased hip adduction at PKSD may indicate both compensatory strategy and reduced hip strength.

  8. A case report of successful treatment of 90° knee flexion contracture in a patient with adult-onset Still's disease.

    PubMed

    He, Qiang; Xiao, Lin; Ma, Jianbing; Zhao, Guanghui

    2016-02-09

    Severe knee flexion contractures greater than 80° are rare and challenging to manage. Previous studies have demonstrated unsatisfactory clinical results after correcting these deformities because residual flexion contractures were not corrected within a short period of time. We herein report the case of a patient with adult-onset Still's disease with 90° of bilateral knee flexion contracture, which was successfully corrected by total knee arthroplasty and serial casting over a period of five weeks. A 47-year-old male was admitted to our orthopedic department for bilateral knee pain and a preoperative fixed flexion contracture of 90°. A diagnosis of adult-onset Still's disease was made based on the patient's medical history of a high spiking fever, salmon-colored rash and bilateral knee and wrist pain. Bilateral total knee arthroplasty was carried out to address these deformities, but residual flexion contracture was present. Subsequently, serial casting was used to achieve full extension at four weeks after surgery. Excellent function and patient satisfaction were observed at two years of follow-up. The new protocol of total knee arthroplasty with subsequent serial casting seems to be an efficient solution for knee flexion contractures greater than 80°. This report adds to the very small number of reported cases of adult-onset Still's disease with severe knee flexion contractures and describes a patient who was successfully treated with a new protocol.

  9. Surgical Release of Severe Flexion Contracture for Oncologic Knee Arthroplasty

    PubMed Central

    Ng, Vincent Y.

    2017-01-01

    Background: Severe postoperative knee contractures after arthroplasty or megaprosthesis reconstruction occur rarely, but are devastating complications. Management of preoperative flexion contractures is well-described, but there is a paucity of literature for surgical treatment of postoperative contractures. A retrospective chart review was performed for a single surgeon of cases between 1996 and 2014. Results: Nine patients (5 of 66 for pediatrics; 4 of 95 for adults) underwent surgical release for severe stiffness after implantation of knee megaprosthesis. The total arc of motion was improved from a preoperative mean of 34° (range, 10° to 70°) to a postoperative mean 89° (63° to 125°). The amount of extension improved by a mean of 27° (range, -3° to +70°) and the amount of flexion improved by a mean of 28° (range, -10° to +75°). Conclusion: Surgical release of severe postoperative knee contracture is a challenging procedure, but in most cases, the amount of extension and flexion can be improved, yielding a greater total arc of motion. PMID:28400872

  10. The effect of posterior tibial slope on knee flexion in posterior-stabilized total knee arthroplasty.

    PubMed

    Shi, Xiaojun; Shen, Bin; Kang, Pengde; Yang, Jing; Zhou, Zongke; Pei, Fuxing

    2013-12-01

    To evaluate and quantify the effect of the tibial slope on the postoperative maximal knee flexion and stability in the posterior-stabilized total knee arthroplasty (TKA). Fifty-six patients (65 knees) who had undergone TKA with the posterior-stabilized prostheses were divided into the following 3 groups according to the measured tibial slopes: Group 1: ≤4°, Group 2: 4°-7° and Group 3: >7°. The preoperative range of the motion, the change in the posterior condylar offset, the elevation of the joint line, the postoperative tibiofemoral angle and the preoperative and postoperative Hospital for Special Surgery (HSS) scores were recorded. The tibial anteroposterior translation was measured using the Kneelax 3 Arthrometer at both the 30° and the 90° flexion angles. The mean values of the postoperative maximal knee flexion were 101° (SD 5), 106° (SD 5) and 113° (SD 9) in Groups 1, 2 and 3, respectively. A significant difference was found in the postoperative maximal flexion between the 3 groups (P < 0.001). However, no significant differences were found between the 3 groups in the postoperative HSS scores, the changes in the posterior condylar offset, the elevation of the joint line or the tibial anteroposterior translation at either the 30° or the 90° flexion angles. A 1° increase in the tibial slope resulted in a 1.8° flexion increment (r = 1.8, R (2) = 0.463, P < 0.001). An increase in the posterior tibial slope can significantly increase the postoperative maximal knee flexion. The tibial slope with an appropriate flexion and extension gap balance during the operation does not affect the joint stability.

  11. Sagittal plane joint loading is related to knee flexion in osteoarthritic gait.

    PubMed

    Creaby, Mark W; Hunt, Michael A; Hinman, Rana S; Bennell, Kim L

    2013-10-01

    High mechanical loading has been consistently linked with medial tibiofemoral osteoarthritis, and is considered to play a central role in the pathogenesis of the disease. Evidence from healthy adults indicates that knee flexion kinematics may influence knee load. The purpose of this study therefore, was to investigate the association between knee flexion kinematics and indicators of joint loading during walking (peak moments and vertical ground reaction force), in individuals with medial tibiofemoral osteoarthritis. In this cross-sectional study, 89 participants with painful medial tibiofemoral osteoarthritis completed three-dimensional walking gait analysis to measure stance phase ground reaction forces, knee joint moments, and knee flexion kinematics. In stepwise regression, greater knee flexion excursion was associated with higher peak vertical ground reaction force, accounting for 10% of its variance (B=0.62 [95% CI 0.34, 0.89], P<0.001). Greater peak knee flexion was associated with a higher flexion moment, accounting for 44% of its variance (B=0.12 [95% CI 0.09, 0.15], P<0.001). No association was found between the knee adduction moment and knee flexion kinematics during walking. Our data suggest that greater knee flexion is associated with higher joint loads in the sagittal plane (i.e. a higher peak knee flexion moment). However, knee flexion kinematics were not associated with the knee adduction moment - a proxy measure of medial compartment knee load. Thus, high knee flexion should be considered an undesirable gait characteristic with respect to knee load in individuals with medial tibiofemoral osteoarthritis. © 2013.

  12. Mechanisms underpinning the peak knee flexion moment increase over 2-years following arthroscopic partial meniscectomy.

    PubMed

    Hall, Michelle; Wrigley, Tim V; Metcalf, Ben R; Hinman, Rana S; Cicuttini, Flavia M; Dempsey, Alasdair R; Mills, Peter M; Lloyd, David G; Bennell, Kim L

    2015-12-01

    Knee osteoarthritis is common in people who have undergone partial meniscectomy, and a higher external knee flexion moment during gait may be a potential contributor. Although the peak external knee flexion moment has been shown to increase from 3 months to 2 years following partial meniscectomy, mechanisms underpinning the increase in the peak knee flexion moment are unknown. Sixty-six participants with partial meniscectomy completed three-dimensional gait (normal and fast pace) and quadriceps strength assessment at baseline (3 months following partial meniscectomy) and again 2 years later. Variables included external knee flexion moment, vertical ground reaction force, knee flexion kinematics, and quadriceps peak torque. For normal pace walking, the main significant predictors of change in peak knee flexion moment were an increase in peak vertical ground reaction force (R(2)=0.55), mostly due to an increase in walking speed, and increase in peak knee flexion angle (R(2)=0.19). For fast pace walking, the main significant predictors of change in peak knee flexion moment were an in increase in peak vertical ground reaction force (R(2)=0.51) and increase in knee flexion angle at initial contact (R(2)=0.17). Change in peak vertical force was mostly due to an increase in walking speed. Findings suggest that increases in vertical ground reaction force and peak knee flexion angle during stance are predominant contributors to the 2-year change in peak knee flexion moment. Future studies are necessary to refine our understanding of joint loading and its determinants following meniscectomy. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. The natural history of a newly developed flexion contracture following primary total knee arthroplasty.

    PubMed

    Anania, Andres; Abdel, Matthew P; Lee, Yuo-yu; Lyman, Stephen; González Della Valle, Alejandro

    2013-10-01

    We investigated the incidence, natural history, and functional consequences of a newly developed flexion contracture after total knee arthroplasty (TKA). Forty patients with full knee extension preoperatively who developed a postoperative flexion contracture were match-paired 1:2 with 80 patients who had full extension. The incidence of a newly developed flexion contracture, ROM, and Knee Society scores (KSS) at six weeks, four months, and one year were analysed. The incidence of a new flexion contracture at six weeks was 14%, but diminished to 5% and 0.3% at four months and one year, respectively. One year after surgery, there was no difference in the KSS (p = 0.5). This study showed that the majority of patients who developed a new flexion contracture after TKA have full knee extension one year postoperatively. Moreover, knee extension and KSS at one year are equivalent to those patients who did not developed a flexion contracture.

  14. Modelling knee flexion effects on joint power absorption and adduction moment.

    PubMed

    Nagano, Hanatsu; Tatsumi, Ichiroh; Sarashina, Eri; Sparrow, W A; Begg, Rezaul K

    2015-12-01

    Knee osteoarthritis is commonly associated with ageing and long-term walking. In this study the effects of flexing motions on knee kinetics during stance were simulated. Extended knees do not facilitate efficient loading. It was therefore, hypothesised that knee flexion would promote power absorption and negative work, while possibly reducing knee adduction moment. Three-dimensional (3D) position and ground reaction forces were collected from the right lower limb stance phase of one healthy young male subject. 3D position was sampled at 100 Hz using three Optotrak Certus (Northern Digital Inc.) motion analysis camera units, set up around an eight metre walkway. Force plates (AMTI) recorded ground reaction forces for inverse dynamics calculations. The Visual 3D (C-motion) 'Landmark' function was used to change knee joint positions to simulate three knee flexion angles during static standing. Effects of the flexion angles on joint kinetics during the stance phase were then modelled. The static modelling showed that each 2.7° increment in knee flexion angle produced 2.74°-2.76° increments in knee flexion during stance. Increased peak extension moment was 6.61 Nm per 2.7° of increased knee flexion. Knee flexion enhanced peak power absorption and negative work, while decreasing adduction moment. Excessive knee extension impairs quadriceps' power absorption and reduces eccentric muscle activity, potentially leading to knee osteoarthritis. A more flexed knee is accompanied by reduced adduction moment. Research is required to determine the optimum knee flexion to prevent further damage to knee-joint structures affected by osteoarthritis. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Dynamic knee behaviour: does the knee deformity change as it is flexed-an assessment and classification with computer navigation.

    PubMed

    Deep, Kamal; Picard, Frederic; Baines, Joseph

    2016-11-01

    The aim of this study was to assess the kinematics of arthritic knees prior to TKA. The hypothesis was that the arthritic knee follows distinct patterns with regard to deformity in coronal plane as it flexes from extended position. Data from 585 consecutive arthritic knees that had undergone TKA using two non-image-based navigation systems were included in the study. Coronal plane alignment given by the femoro-tibial mechanical angle (FTMA) was recorded in extension, 30°, 60°, 90° and maximum flexion prior to making any bony cuts or ligamentous releases. Complete data were available for 512 (87.5 %) of arthritic knees. It was found that pre-implant arthritic knees behaved in different distinct patterns from full extension to 90° flexion. These patterns in FTMA from extension through to 90° of flexion were classified into 4 major types (1, 2, 3, and 4) and 8 subgroups (1A, 1B, 2A, 2B, 3, 4A, 4B, 4C) for varus and valgus knees. Beyond 90° of flexion, there were no distinct or consistent patterns. There were differences between varus and valgus knee deformities not only in overall numbers (73.8 % varus vs. 21.1 % valgus) but also in kinematic behaviour. Only 14.1 % of total knees had a consistent deformity (Type 1A) which remained the same throughout the range of flexion. 14.1 % knees actually become opposite deformity as the knee flexes; thus, varus becomes valgus and valgus becomes varus as the knee flexes (Type 3 and 4C). This study has observed and categorised distinct patterns which arthritic knees follow in the coronal plane as it flexes. This dynamic change during flexion will have bearing on collateral releases that are traditionally done based on deformity in extension or 90° flexion mainly. This may be the underlying cause of flexion instability especially for Types 3 and 4C knees if collateral soft tissue release is done based on deformity in extension. Full significance of this remains unknown and will need further investigation. III.

  16. HINGED CAST BRACE FOR PERSISTENT FLEXION CONTRACTURE FOLLOWING TOTAL KNEE REPLACEMENT

    PubMed Central

    Karam, Matthew D; Pugely, Andrew; Callaghan, John J; Shurr, Donald

    2011-01-01

    The reported incidence of persistent knee flexion contracture following total knee arthroplasty (TKA) has varied from 1-15 percent Various treatment modalities have been described in attempts to manage this often difficult problem. This paper describes a novel method of treatment by using a hinged cast brace (previously reported for treatment of femur fractures and knee contractures secondary to hemophilia and cerebral palsy) for use in patients with symptomatic knee flexion contractures. Application of this cast brace with frequent adjustment (every three to four days, initially) toward full extension can often improve knee extension, after physical therapy and other modalities such as extension-assist braces have failed. Care must be taken in the application and use of this device which utilizes frequent manipulations to reduce and maintain the knee flexion angle. We report two clinical cases in which this protocol was effectively used in decreasing symptomatic knee flexion contractures. PMID:22096423

  17. Influence of trunk flexion on hip and knee joint kinematics during a controlled drop landing.

    PubMed

    Blackburn, J Troy; Padua, Darin A

    2008-03-01

    An erect posture and greater knee valgus during landing have been implicated as anterior cruciate ligament injury risk factors. While previous research suggests coupling of knee and hip kinematics, the influence of trunk positioning on lower extremity kinematics has yet to be determined. We hypothesized that greater trunk flexion during landing would result in greater knee and hip flexion and lesser knee valgus. Identification of a modifiable factor (e.g. trunk flexion) which positively influences kinematics of multiple lower extremity joints would be invaluable for anterior cruciate ligament injury prevention efforts. Forty healthy individuals completed two drop landing tasks while knee, hip, and trunk kinematics were sampled. The first task constituted the natural/preferred landing strategy (Preferred), while in the second task, subjects actively flexed the trunk upon landing (Flexed). Peak trunk flexion angle was 47 degrees greater for Flexed compared to Preferred (P<0.001), and was associated with increases in peak hip flexion angle of 31 degrees (P<0.001) and peak knee flexion angle of 22 degrees (P<0.001). Active trunk flexion during landing produces concomitant increases in knee and hip flexion angles. A more flexed/less erect posture during landing is associated with a reduced anterior cruciate ligament injury risk. As such, incorporating greater trunk flexion as an integral component of anterior cruciate ligament injury prevention programs may be warranted.

  18. Isokinetic strength during knee flexion and extension in elite fencers.

    PubMed

    Poulis, I; Chatzis, S; Christopoulou, K; Tsolakis, Ch

    2009-06-01

    The relation of leg preference and muscular strength in elite fencers was examined. The dominant and nondominant extensor and flexor muscles of 30 elite fencers (M age = 18.2 yr., SD = 2.0 yr.; M height = 173 cm, SD=7.4 cm; M weight = 62.7 kg, SD=8.9 kg), who were members of the Greek national team, and 14 healthy, young, sedentary adults (8 men, 6 women; M age 23.4 yr., SD = 1.9; M height = 169 cm, SD = 10.5 cm; M weight = 66.3 kg, SD = 9.9) were tested for concentric isokinetic contraction at slow (30 to 60 degrees/sec.) and fast (240 degrees/sec.) angular velocities. Significant multivariate differences were found between groups for knee extension, angle of knee extension, knee flexion, and flexor/extensor peak torque ratio. In contrast, no significant difference was found between the dominant and nondominant legs. There was no significant difference in the flexor/extensor peak torque ratio among any of the concentric angular velocities tested. These findings suggest that long-term training in fencing influences the strength characteristics of the lower limbs.

  19. Transepicondylar axes for femoral component rotation might produce flexion asymmetry during total knee arthroplasty in knees with proximal tibia vara.

    PubMed

    Park, Il Seok; Ong, Alvin; Nam, Chang Hyun; Ahn, Nong Kyum; Ahn, Hye Sun; Lee, Su Chan; Jung, Kwang Am

    2014-03-01

    Adequate rotation of the femoral component in total knee arthroplasty is mandatory for prevention of numerous adverse sequelae. Therefore, we investigate whether there is the distal femoral deformity in knees with tibia vara. The purpose of this study was to evaluate the reliability of the transepicondylar axis as a rotational landmark in knees with tibia vara. We retrospectively reviewed and selected 101 osteoarthritic knees with proximal tibia vara and 150 osteoarthritic knees without tibia vara for inclusion in this study. The transepicondylar axis (TEA), anteroposterior (AP) axis and posterior condylar (PC) line were measured using the axial image from magnetic resonance imaging axial images. We compared the external rotation angle of the TEA relative to the PC line between groups in order to investigate the presence of distal femoral anatomical adaptation in the tibia vara group. The TEA in the tibia vara group had 6.1º of external rotation relative to the PC line, which was not significantly different from the 6.0º of external rotation in the non-tibia vara group. The line perpendicular to the AP axis in the tibia vara group had 6.1º of external rotation relative to the PC line, which was not significantly different from the 5.4º of external rotation in the non-tibia vara group. Distal femoral geometry was unaffected by the tibia vara deformity. The use of transepicondylar axes in determining femoral rotation may produce flexion asymmetry in knees with tibia vara. Level III. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Knee extension and flexion: MR delineation of normal and torn anterior cruciate ligaments

    SciTech Connect

    Niitsu, Mamoru; Ikeda, Kotaroh; Fukubayashi, Tohru; Anno, Izumi; Itai, Yuji

    1996-03-01

    Our goal was to assess the effect of joint position of semiflexed and extended knees in MR delineation of the anterior cruciate ligament (ACL). With a mobile knee brace and a flexible surface coil, the knee joint was either fully extended or bent to a semiflexed position (average 45{degrees} of flexion) within the magnet bore. Sets of oblique sagittal MR images were obtained for both extended and flexed knee positions. Thirty-two knees with intact ACLs and 43 knees with arthroscopically proven ACL tears were evaluated. Two observers compared paired MR images of both extended and flexed positions and rated them by a relative three point scale. Anatomic correlation in MR images was obtained by a cadaveric knee with incremental flexion. The MR images of flexed knees were more useful than of extended knees in 53% of the case reviews of femoral attachments and 36% of reviews of midportions of normal ACLs. Compared with knee extensions, the MR images for knee flexion provided better clarity in 48% of reviews of disrupted sites and 52% of residual bundles of torn ACLs. Normal ACL appeared taut in the knee extension and lax in semiflexion. Compared with MR images of knees in extension, MR images of knees in flexion more clearly delineate the femoral side of the ligament with wider space under the intercondylar roof and with decreased volume-averaging artifacts, providing superior visualization of normal and torn ACLs. 13 refs., 7 figs., 1 tab.

  1. Quengel Casting for the Management of Pediatric Knee Flexion Contractures: A 26-Year Single Institution Experience.

    PubMed

    Wiley, Marcel R; Riccio, Anthony I; Felton, Kevin; Rodgers, Jennifer A; Wimberly, Robert L; Johnston, Charles E

    Quengel casting was introduced in 1922 for nonsurgical treatment of knee flexion contractures (KFC) associated with hemophilic arthropathy. It consists of an extension-desubluxation hinge fixed to a cast allowing for gradual correction of a flexion deformity while preventing posterior tibial subluxation. The purpose of this study is to report 1 center's experience with this technique for the treatment of pediatric KFC. A retrospective review was conducted over a 26-year period. All patients with KFC treated with Quengel casting were included. Demographic data, associated medical conditions, adjunctive soft tissue releases, complications, and the need for late surgical intervention were recorded. Tibiofemoral angle measurements in maximal extension were recorded at initiation and termination of casting, 1-year follow-up, and final follow-up. Success was defined as no symptomatic recurrence of KFC or need for subsequent surgery. Eighteen patients (26 knees) were treated for KFC with Quengel casting. Average age at initiation of casting was 8.1 years with average follow-up of 59.9 months. Fifteen knees (58%) underwent soft tissue releases before casting. An average of 1.5 casts per knee were applied over an average of 23.9 days. Average KFC before casting was 50.6 degrees (range, 15 to 100 degrees) which improved to 5.96 degrees (0 to 40 degrees) at cast removal (P<0.00001). Sixteen patients (22 knees) had 1-year follow-up or failed casting before 1 year. Of these, 11 knees (50%) had a successful outcome. Residual KFC of those treated successfully was 6.8 degrees (range, 0 to 30 degrees) at 1 year and 8.2 degrees (range, 0 to 30 degrees) at final follow-up, averaging 71.4 months (P=0.81). Of the 11 knees deemed failures, all had recurrence of deformity within an average of 1 year from cast removal. Surgical release before Quengel casting did not improve the chances for success (P=0.09). Quengel casting can improve pediatric KFC an average of 44.2 degrees with minimal

  2. In-vivo spinal cord deformation in flexion

    NASA Astrophysics Data System (ADS)

    Yuan, Qing; Dougherty, Lawrence; Margulies, Susan S.

    1997-05-01

    Traumatic mechanical loading of the head-neck complex results cervical spinal cord injury when the distortion of the cord is sufficient to produce functional or structural failure of the cord's neural and/or vascular components. Characterizing cervical spinal cord deformation during physiological loading conditions is an important step to defining a comprehensive injury threshold associated with acute spinal cord injury. In this study, in vivo quasi- static deformation of the cervical spinal cord during flexion of the neck in human volunteers was measured using magnetic resonance (MR) imaging of motion with spatial modulation of magnetization (SPAMM). A custom-designed device was built to guide the motion of the neck and enhance more reproducibility. the SPAMM pulse sequence labeled the tissue with a series of parallel tagging lines. A single- shot gradient-recalled-echo sequence was used to acquire the mid-sagittal image of the cervical spine. A comparison of the tagged line pattern in each MR reference and deformed image pair revealed the distortion of the spinal cord. The results showed the cervical spinal cord elongates during head flexion. The elongation experienced by the spinal cord varies linearly with head flexion, with the posterior surface of the cord stretching more than the anterior surface. The maximal elongation of the cord is about 12 percent of its original length.

  3. LIMITED HIP AND KNEE FLEXION DURING LANDING IS ASSOCIATED WITH INCREASED FRONTAL PLANE KNEE MOTION AND MOMENTS

    PubMed Central

    Pollard, Christine D.; Sigward, Susan M.; Powers, Christopher M.

    2009-01-01

    Background It has been proposed that female athletes who limit knee and hip flexion during athletic tasks rely more on the passive restraints in the frontal plane to deceleration their body center of mass. This biomechanical pattern is thought to increase the risk for anterior cruciate ligament injury. To date, the relationship between sagittal plane kinematics and frontal plane knee motion and moments has not been explored. Methods Subjects consisted of fifty-eight female club soccer players (age range: 11 to 20 years) with no history of knee injury. Kinematics, ground reaction forces, and surface electromyography were collected while each subject performed a drop landing task. Subjects were divided into two groups based on combined sagittal plane knee and hip flexion angles during the deceleration phase of landing (high flexion and low flexion). Findings Subjects in the low flexion group demonstrated increased knee valgus angles (P = 0.02, effect size 0.27), increased knee adductor moments (P = 0.03, effect size 0.24), decreased energy absorption at the knee and hip (P = 0.02, effect size 0.25; and P< 0.001, effect size 0.59), and increased vastus lateralis EMG when compared to subjects in the high flexion group (P = 0.005, effect size 0.35). Interpretation Female athletes with limited sagittal plane motion during landing exhibit a biomechanical profile that may put these individuals at greater risk for anterior cruciate ligament injury. PMID:19913961

  4. Crouched gait in myelomeningocele: a comparison between the degree of knee flexion contracture in the clinical examination and during gait.

    PubMed

    Moen, Todd; Gryfakis, Nicholas; Dias, Luciano; Lemke, Laura

    2005-01-01

    The purpose of this study was to quantitatively evaluate, in patients with low lumbar and sacral level myelomeningocele who have knee flexion contractures, whether there are significant differences between the degree of knee flexion contracture measured clinically and the degree of actual knee flexion during gait, measured by computerized gait analysis. Patients were divided into two groups, those who walked with ankle-foot orthoses (AFOs) alone and those who walked with AFOs and crutches. In both groups, the patient's knee flexion contractures were measured clinically, and the degree of knee flexion was measured dynamically at two representative points in the gait cycle. In both groups and at both points of the gait cycle, the degree of knee flexion during gait was significantly greater than the degree of clinical knee flexion contracture. This should be taken into account when evaluating the crouch gait of children with myelomeningocele and planning the proper treatment.

  5. Analysis of muscle activation patterns during transitions into and out of high knee flexion postures.

    PubMed

    Tennant, Liana M; Maly, Monica R; Callaghan, Jack P; Acker, Stacey M

    2014-10-01

    Increased risk of medial tibiofemoral osteoarthritis (OA) is linked to occupations that require frequent transitions into and out of postures which require high knee flexion (>90°). Muscle forces are major contributors to joint loading, and an association between compressive forces due to muscle activations and the degeneration of joint cartilage has been suggested. The purpose of this study was to evaluate muscle activation patterns of muscles crossing the knee during transitions into and out of full-flexion kneeling and squatting, sitting in a low chair, and gait. Both net and co-activation were greater when transitioning out of high flexion postures, with maximum activation occurring at knee angles greater than 100°. Compared to gait, co-activation levels during high flexion transitions were up to approximately 3 times greater. Co-activation was significantly greater in the lateral muscle group compared to the medial group during transitions into and out of high flexion postures. These results suggest that compression due to activation of the medial musculature of the knee may not be the link between high knee flexion postures and increased medial knee OA observed in occupational settings. Further research on a larger subject group and workers with varying degrees of knee OA is necessary.

  6. External Knee Adduction and Flexion Moments during Gait and Medial Tibiofemoral Disease Progression in Knee Osteoarthritis

    PubMed Central

    Chang, Alison H.; Moisio, Kirsten C.; Chmiel, Joan S.; Eckstein, Felix; Guermazi, Ali; Prasad, Pottumarthi V.; Zhang, Yunhui; Almagor, Orit; Belisle, Laura; Hayes, Karen; Sharma, Leena

    2015-01-01

    Objective Test the hypothesis that greater baseline peak external knee adduction moment (KAM), KAM impulse, and peak external knee flexion moment (KFM) during the stance phase of gait are associated with baseline-to-2-year medial tibiofemoral cartilage damage and bone marrow lesion progression, and cartilage thickness loss. Methods Participants all had knee OA in at least one knee. Baseline peak KAM, KAM impulse, and peak KFM (normalized to body weight and height) were captured and computed using a motion analysis system and 6 force plates. Participants underwent MRI of both knees at baseline and two years later. To assess the association between baseline moments and baseline-to-2-year semiquantitative cartilage damage and bone marrow lesion progression and quantitative cartilage thickness loss, we used logistic regression with generalized estimating equations (GEE), adjusting for gait speed, age, gender, disease severity, knee pain severity, and medication use. Results The sample consisted of 391 knees (204 persons): mean age 64.2 years (SD 10.0); BMI 28.4 kg/m2 (5.7); 156 (76.5%) women. Greater baseline peak KAM and KAM impulse were each associated with worsening of medial bone marrow lesions, but not cartilage damage. Higher baseline KAM impulse was associated with 2-year medial cartilage thickness loss assessed both as % loss and as a threshold of loss, whereas peak KAM was related only to % loss. There was no relationship between baseline peak KFM and any medial disease progression outcome measures. Conclusion Findings support targeting KAM parameters in an effort to delay medial OA disease progression. PMID:25677110

  7. Clinical evaluation of 292 Genesis II posterior stabilized high-flexion total knee arthroplasty: range of motion and predictors.

    PubMed

    Fuchs, Mathijs C H W; Janssen, Rob P A

    2015-01-01

    The primary aim of the study was to evaluate the range of motion and complications after Genesis II total knee arthroplasty with high-flexion tibia insert (TKA-HF). Furthermore, difference in knee flexion between high flexion and standard inserts was compared. The hypothesis was that knee flexion is better after high-flexion TKA. A total of 292 TKA-HF were retrospectively reviewed. Mean follow-up was 24.3 months. The range of motion was compared between TKA-HF (high-flexion group) and a comparable cohort of 86 Genesis II TKA with a standard tibia insert (control group). Surgeries were performed by one experienced knee orthopedic surgeon. Knee flexion in the high-flexion group increased from 114.8° preoperatively to 118.0° postoperatively (P < 0.01). Knee extension in the high-flexion group increased from -4.5° preoperatively to -0.4° after surgery (P < 0.01). Mean knee flexion was 5.52° (± 1.46°) better in the high-flexion group compared with the control group (P < 0.01). Preoperative range of motion, body mass index, diabetes mellitus and patellofemoral pain significantly influenced range of motion. Few complications occurred after TKA-HF. The Genesis II TKA-HF showed good short-term results with limited complications. Knee flexion after Genesis II TKA-HF was better compared with a standard tibia insert.

  8. The Effect of Patellar Thickness on Intraoperative Knee Flexion and Patellar Tracking in Patients With Arthrofibrosis Undergoing Total Knee Arthroplasty.

    PubMed

    Kim, Abraham D; Shah, Vivek M; Scott, Richard D

    2016-05-01

    We evaluated the intraoperative effect of patellar thickness on intraoperative passive knee flexion and patellar tracking during total knee arthroplasty (TKA) in patients with preoperative arthrofibrosis and compared them to patients with normal preoperative range of motion (ROM) documented in a prior study. Routine posterior cruciate ligament-retaining TKA was performed in a total of 34 knees, 23 with normal ROM and 11 with arthrofibrosis, defined as ≤100° of passive knee flexion against gravity under anesthesia. Once clinical balance and congruent patellar tracking were established, custom trial patellar components thicker than the standard trial by 2-mm increments (2-8 mm) were sequentially placed and trialed. Passive flexion against gravity was recorded using digital photograph goniometry. Gross mechanics of patellofemoral tracking were visually assessed. On average, passive knee flexion decreased 2° for every 2-mm increment of patellar thickness (P < .0001), which was similar to patients with normal preoperative ROM. In addition, increased patellar thickness had no gross effect on patellar subluxation and tilt in patients with arthrofibrosis as well as those with normal ROM. Patellar thickness had a modest effect on intraoperative passive flexion and no effect on patellar tracking in patients with arthrofibrosis undergoing TKA. There was no marked difference in intraoperative flexion and patellar tracking between patients with arthrofibrosis and patients with normal preoperative ROM. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Stance controlled knee flexion improves stimulation driven walking after spinal cord injury

    PubMed Central

    2013-01-01

    Background Functional neuromuscular stimulation (FNS) restores walking function after paralysis from spinal cord injury via electrical activation of muscles in a coordinated fashion. Combining FNS with a controllable orthosis to create a hybrid neuroprosthesis (HNP) has the potential to extend walking distance and time by mechanically locking the knee joint during stance to allow knee extensor muscle to rest with stimulation turned off. Recent efforts have focused on creating advanced HNPs which couple joint motion (e.g., hip and knee or knee and ankle) to improve joint coordination during swing phase while maintaining a stiff-leg during stance phase. Methods The goal of this study was to investigate the effects of incorporating stance controlled knee flexion during loading response and pre-swing phases on restored gait. Knee control in the HNP was achieved by a specially designed variable impedance knee mechanism (VIKM). One subject with a T7 level spinal cord injury was enrolled and served as his own control in examining two techniques to restore level over-ground walking: FNS-only (which retained a stiff knee during stance) and VIKM-HNP (which allowed controlled knee motion during stance). The stimulation pattern driving the walking motion remained the same for both techniques; the only difference was that knee extensor stimulation was constant during stance with FNS-only and modulated together with the VIKM to control knee motion during stance with VIKM-HNP. Results Stance phase knee angle was more natural during VIKM-HNP gait while knee hyperextension persisted during stiff-legged FNS-only walking. During loading response phase, vertical ground reaction force was less impulsive and instantaneous gait speed was increased with VIKM-HNP, suggesting that knee flexion assisted in weight transfer to the leading limb. Enhanced knee flexion during pre-swing phase also aided flexion during swing, especially when response to stimulation was compromised. Conclusions

  10. Differences in knee flexion between the Genium and C-Leg microprocessor knees while walking on level ground and ramps.

    PubMed

    Lura, Derek J; Wernke, Matthew M; Carey, Stephanie L; Kahle, Jason T; Miro, Rebecca M; Highsmith, M Jason

    2015-02-01

    Microprocessor knees have improved the gait and functional abilities of persons with transfemoral amputation. The Genium prosthetic knee offers an advanced sensor and control system designed to decrease impairment by: allowing greater stance phase flexion, easing transitions between gait phases, and compensating for changes in terrain. The aim of this study was to determine differences between the knee flexion angle of persons using the Genium knee, the C-Leg knee, and non-amputee controls; and to evaluate the impact the prostheses on gait and level of impairment of the user. This study used a randomized experimental crossover of persons with transfemoral amputation using the Genium and C-Leg microprocessor knees (n=25), with an observational sample of non-amputee controls (n=5). Gait analysis by 3D motion tracking of subjects ambulating at different speeds on level ground and on 5° and 10° ramps was completed. Use of the Genium resulted in a significant increase in peak knee flexion for swing (5°, p<0.01, d=0.34) and stance (2°, p<0.01, d=0.19) phases relative to C-Leg use. There was a high degree of variability between subjects, and significant differences still remain between the Genium group and the control group's knee flexion angles for most speeds and slopes. The Genium knee generally increases flexion in swing and stance, potentially decreasing the level of impairment for persons with transfemoral amputation. This study demonstrates functional differences between the C-Leg and Genium knees to help prosthetists determine if the Genium will provide functional benefits to individual patients. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. A new static progressive splint for treatment of knee and elbow flexion contractures.

    PubMed

    Suksathien, Rachawan; Suksathien, Yingyong

    2010-07-01

    Knee and elbow flexion contractures are a frequent cause of ambulation and function problems that often require extensive rehabilitation. Traditional methods are of limited benefit in severe and fixed contracture. A new static progressive splint was developed from daily-use knee and elbow orthosis and a newly invented gradual telescopic rod, which is designed to provide low load, and gradual and prolonged stretching. The splint was used in ten cases (11 knees) of knee flexion contracture and three cases of elbow flexion contracture. There were multiple etiologies of contracture such as burn scar contractures, intra-articular fractures, septic arthritis, juvenile rheumatoid arthritis, and immobilization. The average timing of the contracture before splinting was 14.6 months (range, 2 to 36) in the knee group and 16.7 months (range, 6 to 30) in the elbow group. The average initial extension was -53.6 degrees (range, -30 to -85) in the knee group and -70 degrees (range -65 to -80) in the elbow group. The average post treatment extension was -15 degrees (range, 0 to -30) in the knee group and -38.3 degrees (range, -30 to -45) in the elbow group. The average duration of treatment was 9.2 weeks (range, 4 to 16) in the knee group and 14 weeks (range, 11 to 20) in the elbow group. The most dramatic result was found in the patient who had burn scar flexion contractures of both knees for 20 months. The knee extensions increased from -60 and-85 degrees to full extension in four and 14 weeks after treatment, respectively. There were no recurrences or complications from the use of this splint. The patients were able to easily adjust the gradual telescopic rod themselves to provide the appropriate force for stretching. The static progressive splint is a new, effective, and low cost method for treatment of knee and elbow flexion contracture from multiple etiologies. The excellent result was found in extra-articular contracture.

  12. Adjustable bracing technique for the prevention of knee flexion contracture during tibial lengthening.

    PubMed

    Segev, Eitan; Hayek, Shlomo

    2003-01-01

    The authors present a simple thigh-knee brace that prevents flexion contracture during tibial lengthening. The brace is strapped to the thigh and connected to the Ilizarov frame via two simple hinges. While in the brace the knee can be mobilized for physiotherapy and locked in extension during rest.

  13. Computer navigation results in less severe flexion contracture following total knee arthroplasty.

    PubMed

    Bin Abd Razak, Hamid Rahmatullah; Yeo Jin, Seng; Chong Chi, Hwei

    2014-12-01

    We compared postoperative flexion contracture in navigated total knee arthroplasty (TKA) versus conventional TKA. Two groups (Group 1: conventional, Group 2: navigated) of 235 consecutive patients matched for age and gender were retrospectively compared. Range of motion, mechanical axes, Knee Society Scores, Oxford Knee Scores and Short Form-36® (SF-36) scores were collected prospectively and compared preoperatively and at 2years following TKA. At 2years, patients who underwent navigated TKA averaged significantly lesser flexion contracture of 1 degree compared to 6 degrees in patients who underwent conventional TKA. There were a significantly larger proportion of outliers in the conventional group. Computer navigation results in less severe flexion contracture and less frequent flexion contracture of more than 5 degrees as compared to conventional techniques. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Kinematics of passive flexion following balanced and overstuffed fixed bearing unicondylar knee arthroplasty.

    PubMed

    Cassidy, Kevin A; Tucker, Scott M; Rajak, Yogesh; Kia, Mohammad; Imhauser, Carl W; Westrich, Geoffrey H; Heyse, Thomas J

    2015-12-01

    Progression of osteoarthritis in the unreplaced compartment following unicondylar knee arthroplasty (UKA) may be hastened if kinematics is disturbed following UKA implantation. The purpose of this study was to analyze tibiofemoral kinematics of the balanced and overstuffed UKA in comparison with the native knee during passive flexion since this is a common clinical assessment. Ten cadaveric knees were mounted to robotic manipulator and underwent passive flexion from 0 to 90°. The kinematic pathway was recorded in the native knee and in the balanced, fixed bearing UKA. The medial UKA was implanted using a measured resection technique. Additionally, a one millimeter thicker tibial insert was installed to simulate the effects of overstuffing. Tibial kinematics in relation to the femur was recorded. Following UKA the tibia was externally rotated, and in valgus relative to the native knee near extension. In flexion, installing the UKA caused the knee to be translated medially and anteriorly. The tibia was translated distally through the entire range of flexion after UKA. Compared to the balanced UKA, overstuffing further increased valgus at full extension and distal translation of the tibia from full extension to 45° flexion. UKA implantation altered tibiofemoral kinematics in all planes. Differences were small; nevertheless, they may affect tibiofemoral loading patterns. Alterations in tibiofemoral kinematics following UKA might have implications for prosthesis failure and progression of osteoarthritis in the remaining compartment. Overstuffing should be avoided as it further increased valgus and did not improve the remaining kinematics. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. In vivo knee laxity in flexion and extension: a radiographic study in 30 older healthy subjects.

    PubMed

    Heesterbeek, P J C; Verdonschot, N; Wymenga, A B

    2008-01-01

    In order to determine how "tight" a total knee prosthesis should be implanted, it is important to know the amount of laxity in a healthy knee. The objective of this study was to determine knee laxity in extension and flexion in healthy, non-arthritic knees of subjects similar in age to patients undergoing a total knee arthroplasty and to provide guidelines for the orthopaedic surgeon in his attempt to restore the stability of an osteoarthritic knee to normal. Thirty healthy subjects (15 male, 15 female), mean age 62 (SD 6.4) years, were included in the study. For each subject one, randomly selected, knee was stressed in extension and in 70 degrees flexion (15 Nm). Varus and valgus laxity were measured on radiographs. The passive range of motion and active flexion was assessed. Mean valgus laxity in extension was 2.3 degrees (SD 0.9, range 0.2 degrees -4.1 degrees ). In extension mean varus laxity was 2.8 degrees (SD 1.3, range 0.6 degrees -5.4 degrees ). In flexion, mean valgus laxity was 2.5 degrees (SD 1.5, range 0.0 degrees -6.0 degrees ) and mean varus laxity was 3.1 degrees (SD 2.0, range 0.1 degrees -7.0 degrees ). Varus and valgus knee laxity in extension and in flexion were comparable. This study shows that the normal knee in this age group has an inherent degree of varus-valgus laxity. Whether the results of the present study can be used to optimise the total knee arthroplasty implantation technique requires further investigation.

  16. Increased risk of revision for high flexion total knee replacement with thicker tibial liners.

    PubMed

    Namba, R S; Inacio, M C S; Cafri, G

    2014-02-01

    The outcome of total knee replacement (TKR) using components designed to increase the range of flexion is not fully understood. The short- to mid-term risk of aseptic revision in high flexion TKR was evaluated. The endpoint of the study was aseptic revision and the following variables were investigated: implant design (high flexion vs non-high flexion), the thickness of the tibial insert (≤ 14 mm vs > 14 mm), cruciate ligament (posterior stabilised (PS) vs cruciate retaining), mobility (fixed vs rotating), and the manufacturer (Zimmer, Smith & Nephew and DePuy). Covariates included patient, implant, surgeon and hospital factors. Marginal Cox proportional hazard models were used. In a cohort of 64 000 TKRs, high flexion components were used in 8035 (12.5%). The high flexion knees with tibial liners of thickness > 14 mm had a density of revision of 1.45/100 years of observation, compared with 0.37/100 in non-high flexion TKR with liners ≤ 14 mm thick. Relative to a standard fixed PS TKR, the NexGen (Zimmer, Warsaw, Indiana) Gender Specific Female high flexion fixed PS TKR had an increased risk of revision (hazard ratio (HR) 2.27 (95% confidence interval (CI) 1.48 to 3.50)), an effect that was magnified when a thicker tibial insert was used (HR 8.10 (95% CI 4.41 to 14.89)). Surgeons should be cautious when choosing high flexion TKRs, particularly when thicker tibial liners might be required.

  17. The Effect of Stabilization on Isokinetic Knee Extension and Flexion Torque Production

    PubMed Central

    Magnusson, S. Peter; Geismar, Richard A.; Gleim, Gilbert W.; Nicholas, James A.

    1993-01-01

    The purpose of this study was to examine the effect of four methods of stabilization on maximal reciprocal isokinetic knee extension and flexion. Left knee extension/flexion was tested at 60°/s in 20 subjects. Warm-up consisted of five submaximal and one maximal effort followed by three maximal efforts in each of four randomized stabilization conditions: 1) Hands and back stabilization; the trunk was strapped to the back rest and the hands grasped the seat. 2) Back stabilization; the trunk was strapped to the back rest and the hands were folded across the chest. 3) Hand stabilization; the hands grasped the seat and the back rest was removed. 4) No stabilization; the hands were folded across the chest and the back rest was removed. One-way repeated measures ANOVA showed a significant effect of stabilization for knee extension (F(3,57)=17.44, p=.0001) and knee flexion (F(3,57)= 5.37, p=.002). Paired, two-tailed student's t-tests with Bonferroni correction showed that, in knee extension, no stabilization was significantly less than all others, p<.001. In addition, back stabilization was less than hands and back stabilization, p<.005. In knee flexion, no stabilization was significantly less than all others, p<.01. In conclusion, the method of trunk stabilization significantly affected maximal reciprocal isokinetic knee extension/flexion strength measurements. Maximal knee extension/flexion torque production was achieved when the trunk was strapped to the back support and when the hands grasped the seat. ImagesFig 1a.Fig 1b.Fig 1c.Fig 1d. PMID:16558235

  18. Bilateral Medial Tibiofemoral Joint Stiffness in Full Extension and 20° of Knee Flexion

    PubMed Central

    Aronson, Patricia A; Rijke, Arie M; Ingersoll, Christopher D

    2008-01-01

    Context: The valgus stress test is used clinically to assess injury to the medial knee structures in 2 positions: full extension and some degree of flexion. The amount of flexion used to “isolate” the medial collateral ligament is not consistent in the literature, but most studies have shown that stiffness of the ligaments was consistent between the limbs. Objective: To determine (1) if the stiffness of the medial knee structures was the same bilaterally, and (2) if the stiffness was different in full extension compared with 20° of knee flexion. Design: Criterion standard, before-after design. Setting: University research laboratory. Patients or Other Participants: Both knees of 45 healthy and active volunteers (26 females, 19 males; age  =  23.2 ± 3.96 years, height  =  170.6 ± 7.75 cm, mass  =  74.2 ± 15.14 kg) were studied. Intervention(s): A valgus force of 60 N was applied to the lateral aspect of both knees in full extension and in 20° of flexion. Main Outcome Measure(s): The slope of the force-strain line of the medial knee during a valgus force was calculated using the LigMaster arthrometer. Results: Slope means in full extension were 16.1 ± 3.3 (right knee) and 15.8 ± 3.1(left knee). Means for 20° of flexion were 12.2 ± 3.1 (right) and 11.7 ± 2.8 (left). Stiffness was greater when the knee was in full extension versus 20° of flexion (t44  =  12.04, P < .001). No difference was noted between the slopes of the 2 knees in extension (t44  =  0.74, P  =  .46) or in flexion (t44  =  1.2, P  =  .27). Conclusions: These findings support the use of the contralateral knee as a control. Further, the valgus stress test should be performed in full extension and in some degree of flexion to assess the different restraining structures of the medial tibiofemoral joint. PMID:18345340

  19. Intraoperative medial pivot affects deep knee flexion angle and patient-reported outcomes after total knee arthroplasty.

    PubMed

    Nishio, Yusuke; Onodera, Tomohiro; Kasahara, Yasuhiko; Takahashi, Daisuke; Iwasaki, Norimasa; Majima, Tokifumi

    2014-04-01

    The aim of this study was to evaluate the relationship between clinical results including patient-reported outcomes and intraoperative knee kinematic patterns after total knee arthroplasty (TKA). A cross-sectional survey of forty consecutive medial osteoarthritis patients who had a primary TKA using a CT-based navigation system was conducted. Subjects were divided into two groups based on intraoperative kinematic patterns: a medial pivot group (n = 20) and a non-medial pivot group (n = 20). Subjective outcomes with the new Knee Society Score and clinical outcomes were evaluated. The functional activities, patient satisfaction and the knee flexion angle of the medial pivot group were significantly better than those of the non-medial pivot group. An intraoperative medial pivot pattern positively influences deep knee flexion and patient-reported outcomes.

  20. Physical therapy intervention for an adolescent with a knee flexion contracture and diagnosis of multiple pterygium syndrome.

    PubMed

    Bellamy, Sandra Gail; Gibbs, Karen; Lazaro, Rolando

    2007-01-01

    The purpose of this case report is to describe a course of physical therapy for a client with a rare genetic condition, multiple pterygium syndrome (MPS). MPS is a rare genetic disorder characterized by connective tissue webbing across multiple joints, dysmorphic facies, and various visceral and skeletal deformities. Before the patient commenced physical therapy, surgical amputation was recommended for the client's knee flexion contracture. The client's treatment plan included stretching, manual therapy, and resisted exercise. Long-term outcomes were decreased back and knee pain and improved range of motion, strength, and ambulation. Therapists using techniques to improve joint range of motion in clients with MPS should be aware that pterygia may include contractile tissue, nerves, and blood vessels and there may be underlying skeletal deformity or weakness in these areas. Children with MPS are at high risk of developing scoliosis and should be appropriately assessed in early childhood.

  1. Significant effect of the posterior tibial slope and medial/lateral ligament balance on knee flexion in total knee arthroplasty.

    PubMed

    Fujimoto, Eisaku; Sasashige, Yoshiaki; Masuda, Yasuji; Hisatome, Takashi; Eguchi, Akio; Masuda, Tetsuo; Sawa, Mikiya; Nagata, Yoshinori

    2013-12-01

    The intra-operative femorotibial joint gap and ligament balance, the predictors affecting these gaps and their balances, as well as the postoperative knee flexion, were examined. These factors were assessed radiographically after a posterior cruciate-retaining total knee arthroplasty (TKA). The posterior condylar offset and posterior tibial slope have been reported as the most important intra-operative factors affecting cruciate-retaining-type TKAs. The joint gap and balance have not been investigated in assessments of the posterior condylar offset and the posterior tibial slope. The femorotibial gap and medial/lateral ligament balance were measured with an offset-type tensor. The femorotibial gaps were measured at 0°, 45°, 90° and 135° of knee flexion, and various gap changes were calculated at 0°-90° and 0°-135°. Cruciate-retaining-type arthroplasties were performed in 98 knees with varus osteoarthritis. The 0°-90° femorotibial gap change was strongly affected by the posterior condylar offset value (postoperative posterior condylar offset subtracted by the preoperative posterior condylar offset). The 0°-135° femorotibial gap change was significantly correlated with the posterior tibial slope and the 135° medial/lateral ligament balance. The postoperative flexion angle was positively correlated with the preoperative flexion angle, γ angle and the posterior tibial slope. Multiple-regression analysis demonstrated that the preoperative flexion angle, γ angle, posterior tibial slope and 90° medial/lateral ligament balance were significant independent factors for the postoperative knee flexion angle. The flexion angle change (postoperative flexion angle subtracted by the preoperative flexion angle) was also strongly correlated with the preoperative flexion angle, posterior tibial slope and 90° medial/lateral ligament balance. The postoperative flexion angle is affected by multiple factors, especially in cruciate-retaining-type TKAs. However, it is

  2. Adaptations during the stance phase of gait for simulated flexion contractures at the knee.

    PubMed

    Cerny, K; Perry, J; Walker, J M

    1994-06-01

    Adaptations in the stance phase of gait to knee flexion contractures simulated by a knee-ankle-foot orthosis were studied in 20 healthy women (mean age: 25 +/- 3.6 years). Stride characteristics, joint postures, floor reactions, and indwelling electromyographic activity of the lower gluteus maximus, vastus lateralis, long head of the biceps femoris, and soleus muscles were measured during walking with the orthosis, with and without contracture simulation. Simulated knee flexion contracture resulted in decreased stride length and velocity and increased forefoot weight bearing and flexion posture in stance. Increases were also seen in magnitude and/or duration of flexion floor reaction torques and gluteus maximus, vastus lateralis, and soleus muscle activity. The addition of a restriction of plantar flexion resulted in a further decrease in velocity and stride length and a small increase in hip extension posture. These results show that knee flexion contractures, simulated in healthy subjects, cause a decrease in gait function with a simultaneous increase in muscular demand.

  3. Patellofemoral overstuff and its relationship to flexion after total knee arthroplasty.

    PubMed

    Mihalko, William; Fishkin, Zair; Krackow, Kenneth; Krakow, Kenneth

    2006-08-01

    Flexion is an important outcome variable after total knee arthroplasty. Traditionally, matched implant-bone resections of the distal and posterior aspects of the femur are used to prevent loss of knee flexion or extension. However, given limited implant sizes, resection of these portions of the femur may affect the shape of the knee. Variations in the anterior aspects of the femur along with implant size constraints may increase trochlear groove height in the anterior compartment, increase the arc that the extensor mechanism must travel, and thereby decrease passive flexion. We determined the trochlear groove height change in 55 patients after primary total knee arthroplasties. The thickness of the replaced lateral and medial anterior flanges increased by 1.1 +/- 2.6 mm and 0.5 +/- 2.2 mm, respectively, whereas the change in trochlear groove thickness was 0 +/- 1.1 mm. We examined varying amounts of patellofemoral buildup in a cadaver model to observe the effect on passive range of motion of the knee. A 2-mm and 4-mm buildup of the anterior cortex resulted in flexion loss of 1.8 degrees and 4.4 degrees, respectively. The change in the shape of the anterior aspect of the femur may have small effects on flexion but they may not be clinically important.

  4. Effects of hamstring stretching on passive muscle stiffness vary between hip flexion and knee extension maneuvers.

    PubMed

    Miyamoto, N; Hirata, K; Kanehisa, H

    2017-01-01

    The purpose of this study was to examine whether the effects of hamstring stretching on the passive stiffness of each of the long head of the biceps femoris (BFl), semitendinosus (ST), and semimembranosus (SM) vary between passive knee extension and hip flexion stretching maneuvers. In 12 male subjects, before and after five sets of 90 s static stretching, passive lengthening measurements where knee or hip joint was passively rotated to the maximal range of motion (ROM) were performed. During the passive lengthening, shear modulus of each muscle was measured by ultrasound shear wave elastography. Both stretching maneuvers significantly increased maximal ROM and decreased passive torque at a given joint angle. Passive knee extension stretching maneuver significantly reduced shear modulus at a given knee joint angle in all of BFl, ST, and SM. In contrast, the stretching effect by passive hip flexion maneuver was significant only in ST and SM. The present findings indicate that the effects of hamstring stretching on individual passive muscles' stiffness vary between passive knee extension and hip flexion stretching maneuvers. In terms of reducing the muscle stiffness of BFl, stretching of the hamstring should be performed by passive knee extension rather than hip flexion.

  5. Non-surgical Intervention of Knee Flexion Contracture in Children with Spina Bifida: Case Report

    PubMed Central

    Al-Oraibi, Saleh

    2014-01-01

    [Purpose] The purpose of this case report is to describe for the first time, the use of serial casting in the management of knee joint flexion contracture for a young child with spina bifida. [Case Description] The child was 6 years old, and had L3–L4 spina bifida level lesion with quadriceps muscle strength grade 3 +. The child had previously received weekly physiotherapy including stretching for knee flexion contracture on both lower limbs, but without improvement. [Results] The knee flexion contracture, which was not corrected with passive stretching, improved with casting from −40° knee extension to −5° knee extension as measured by a standard goniometer over a period of 4 weeks. Careful measures were taken to ensure skin integrity. At follow up after one-year, the child could ambulate independently with the help of walking aids. [Conclusion] The outcome indicates that using serial casting and follow-up with the use of bracing may be useful for enhancing the walking ability of a young child with spina bifida with knee flexion contractures. Further investigations of serial casting as well as investigation of serial casting with other interventions are warranted. PMID:24926155

  6. Factors affecting the achievement of Japanese-style deep knee flexion after total knee arthroplasty using posterior-stabilized prosthesis with high-flex knee design.

    PubMed

    Niki, Yasuo; Takeda, Yuki; Harato, Kengo; Suda, Yasunori

    2015-11-01

    Achievement of very deep knee flexion after total knee arthroplasty (TKA) can play a critical role in the satisfaction of patients who demand a floor-sitting lifestyle and engage in high-flexion daily activities (e.g., seiza-sitting). Seiza-sitting is characterized by the knees flexed >145º and feet turned sole upwards underneath the buttocks with the tibia internally rotated. The present study investigated factors affecting the achievement of seiza-sitting after TKA using posterior-stabilized total knee prosthesis with high-flex knee design. Subjects comprised 32 patients who underwent TKA with high-flex knee prosthesis and achieved seiza-sitting (knee flexion >145º) postoperatively. Another 32 patients served as controls who were capable of knee flexion >145º preoperatively, but failed to achieve seiza-sitting postoperatively. Accuracy of femoral and tibial component positions was assessed in terms of deviation from the ideal position using a two-dimensional to three-dimensional matching technique. Accuracies of the component position, posterior condylar offset ratio and intraoperative gap length were compared between the two groups. The proportion of patients with >3º internally rotated tibial component was significantly higher in patients who failed at seiza-sitting (41 %) than among patients who achieved it (13 %, p = 0.021). Comparison of intraoperative gap length between patient groups revealed that gap length at 135º flexion was significantly larger in patients who achieved seiza-sitting (4.2 ± 0.4 mm) than in patients who failed at it (2.7 ± 0.4 mm, p = 0.007). Conversely, no significant differences in gap inclination were seen between the groups. From the perspective of surgical factors, accurate implant positioning, particularly rotational alignment of the tibial component, and maintenance of a sufficient joint gap at 135º flexion appear to represent critical factors for achieving >145º of deep knee flexion after TKA.

  7. Measurement of knee flexion/extension angle using wearable UWB radios.

    PubMed

    Qi, Yongbin; Soh, Cheong Boon; Gunawan, Erry; Low, Kay-Soon; Maskooki, Arash

    2013-01-01

    This paper proposes a wearable system using UWB transceivers to measure the knee flexion/extension angle parameter, who is known to be of clinical importance. First, a pair of very small and light antennas is placed on the adjacent segments of knee joint. Then, the range data between these two antennas is acquired using Time of Arrival (TOA) estimator. We further use the measured distance to compute the flexion/extension angle using the law of cosines. The performance of the method was compared with a flexible goniometer by simultaneously measuring knee flexion-extension angle. The experimental results show that the system has reasonable performance and has sufficient accuracy for clinical applications.

  8. A descriptive profile of age‐specific knee extension flexion strength in elite junior tennis players

    PubMed Central

    Ellenbecker, Todd S; Roetert, E Paul; Sueyoshi, Tetsuro; Riewald, Scott

    2007-01-01

    Background Tennis requires repetitive multidirectional movement patterns that can lead to lower extremity injury. Knowledge of population and age‐specific strength parameters can be used during performance enhancement training and rehabilitation of tennis players. Objectives The purpose of this study was to generate population and age‐specific descriptive profiles of concentric isokinetic knee extension and flexion strength in elite junior tennis players, and determine whether bilateral differences exist between extremities and across age ranges. Methods A total of 103 elite male tennis players (mean (SD) 15.92 (2.14), range 11–21) and 53 female tennis players (mean (SD) 15.0 (2.30, range 11–21) were isokinetically tested on a Cybex 6000 isokinetic dynamometer at 180 and 300°/s to assess bilateral concentric knee extension and flexion strength using a standard bilateral testing protocol. Results No significant bilateral difference between the dominant (racquet side) lower extremity and the contralateral non‐dominant side were measured in lower extremity knee extension or flexion strength normalised to body weight, or in the hamstring quadriceps strength ratios in male and female subjects. Male subjects did show significant (p<0.001) increases in knee extension and flexion strength across the age ranges from 11–15 years of age to 16–21 years. Female subjects did not show any significant change in the normalised knee extension or flexion strength across age ranges. Hamstring/quadriceps strength ratios were bilaterally symmetric and remained clinically and statistically constant across age ranges for the male and female elite tennis players. Conclusions Population and age‐specific isokinetic descriptive data from elite tennis players can provide guidance in the development and monitoring of performance enhancement and rehabilitation programs for elite tennis players. The changes identified in normalised knee extension and flexion strength in elite

  9. Innovative application of Cox Flexion Distraction Decompression to the knee: a retrospective case series.

    PubMed

    Albano, Luigi

    2017-08-01

    The purpose of this study is to introduce the application of Cox flexion distraction decompression as an innovative approach to treating knee pain and osteoarthritis. Six months of clinical files from one chiropractic practice were retrospectively screened for patients who had been treated for knee pain. Twenty-five patients met the criteria for inclusion. The treatment provided was Cox flexion distraction decompression. Pre-treatment and post-treatment visual analog pain scales (VAS) were used to measure the results. In total, eight patients presented with acute knee pain (less than three months' duration) and 18 patients presented with chronic knee pain (greater than three months) including two patients with continued knee pain after prosthetic replacement surgery. For all 25 patients, a change was observed in the mean VAS scores from 7.7 to 1.8. The mean number of treatments was 5.3 over an average of 3.0 weeks. Acute patient mean VAS scores dropped from 8.1 to 1.1 within 4.8 treatments over 2.4 weeks. Chronic patient mean VAS scores dropped from 7.5 to 2.2 within 5.4 treatments over 3.3 weeks. No adverse events were reported. This study showed clinical improvement in patients with knee pain who were managed with Cox flexion distraction decompression applied to the knee.

  10. Retrospective comparison of functional and radiological outcome, between two contemporary high flexion knee designs

    PubMed Central

    Kapoor, Vikash; Chatterjee, Daipayan; Hazra, Sutanu; Chatterjee, Anirban; Garg, Parag; Debnath, Kaustav; Mandal, Soham; Sarkar, Sudipto

    2016-01-01

    Introduction: Patient satisfaction after total knee replacement (TKR) depends on the amount of pain relief and the functional activities achieved. An important criterion of good functional outcome is the amount of flexion achieved and whether the patient can manage high flexion activities. In order to increase the amount of safe flexion, various implant designs have been developed. This study aims to compare the outcome after TKR using two contemporary high flexion knee designs: Sigma CR150 High Flex Knee prosthesis (Depuy, Warsaw, Indiana) and NexGen High Flex Knee prosthesis (Zimmer, Warsaw, Indiana). Material: A retrospective study was conducted with 100 cases of each design and their functional and radiological outcome was assessed after two years of follow-up. Results: The two groups had comparable results in terms of subjective satisfaction, range of motion achieved and radiological outcome. Depuy group fared better than Zimmer in terms of functional outcome (modified Oxford knee score). Conclusion: Depuy group was found to have fared better than Zimmer in terms of functional outcome. However, it is very difficult to rate one design above the other based on our small sample size and short duration of follow-up. PMID:27748254

  11. [Investigation of body weight ratios on joint structures at different knee flexion angles in patients with unilateral knee arthroplasty].

    PubMed

    Bakırhan, Serkan; Unver, Bayram; Karatosun, Vasfi

    2013-01-01

    The study aims to determine body weight ratios between extremities in patients with unilateral total knee arthroplasty (TKA) at 12 months postoperatively at the static-standing position at 30, 60 and 90 degrees of knee flexion. The study included 52 female patients (mean age 65.6±10.6 years; range 40 to 83 years) who underwent unilateral primary TKA. The force-platform was used to calculate the body-weight ratios of the patients. Body weight ratios on the operated and non-operated limbs of the unilateral TKA patients were examined at standing-static position at 30, 60 and 90 degrees of knee flexion on the force-platform according to their age and body mass index (BMI). The pain levels of the patients were evaluated using the visual analog scale. It was found that unilateral TKA patients placed their body weight on the non-operated limb more at the standing-static position, and 30, 60 and 90 degrees of knee flexion at 12 months postoperatively (p<0.05). It was also found that as the knee flexion degree increased with age, so did TKA patients place their body weight on the nonoperated limb more (p<0.05), and that BMI had no effect on the load distribution difference over the two extremities (p>0.05). During the postoperative period, load asymmetry between the two extremities in patients with unilateral TKA remains the same due to advancing age. This accelerates the osteoarthritis process on the non-operated knee. It is concluded that the age factor should be taken into account while planning physiotherapy and rehabilitation programs for unilateral TKA patients and knee exercise programs aiming to place load over the operated limb should be arranged.

  12. Measurement of the knee flexion angle with smartphone applications: Which technology is better?

    PubMed

    Jenny, Jean-Yves; Bureggah, Abdullah; Diesinger, Yann

    2016-09-01

    The range of motion of the knee is a critical element of clinical assessment. The tested hypothesis was that the measurement of the knee flexion angle measured with two specific smartphone applications using either inclinometer or camera technology was different from the reference measurement with a navigation system designed for total knee arthroplasty (TKA). Ten consecutive patients were selected for navigation-assisted TKA. Five navigated, five inclinometer and five camera measurements of knee flexion angle were obtained for each patient throughout the complete range of motion. The difference, the correlation and the coherence between all measurements and all paired sub-groups were analysed. There was a strong correlation and a good coherence between the three techniques of measurements, but the knee flexion angle reported by the inclinometer differed substantially from the camera- and navigation-based measurements. The camera-based measurement was clinically identical to the navigated data, with a mean difference of <1° and only 1/50 difference >3°. Camera-based smartphone measurement of the knee range of motion is fit for purpose in a routine clinical setting. The accuracy may be higher than other conventional measurement techniques, allowing a more precise rating of the clinical outcomes after TKA. II.

  13. Quasi-stiffness of the knee joint in flexion and extension during the golf swing.

    PubMed

    Choi, Ahnryul; Sim, Taeyong; Mun, Joung Hwan

    2015-01-01

    Biomechanical understanding of the knee joint during a golf swing is essential to improve performance and prevent injury. In this study, we quantified the flexion/extension angle and moment as the primary knee movement, and evaluated quasi-stiffness represented by moment-angle coupling in the knee joint. Eighteen skilled and 23 unskilled golfers participated in this study. Six infrared cameras and two force platforms were used to record a swing motion. The anatomical angle and moment were calculated from kinematic and kinetic models, and quasi-stiffness of the knee joint was determined as an instantaneous slope of moment-angle curves. The lead knee of the skilled group had decreased resistance duration compared with the unskilled group (P < 0.05), and the resistance duration of the lead knee was lower than that of the trail knee in the skilled group (P < 0.01). The lead knee of the skilled golfers had greater flexible excursion duration than the trail knee of the skilled golfers, and of both the lead and trail knees of the unskilled golfers. These results provide critical information for preventing knee injuries during a golf swing and developing rehabilitation strategies following surgery.

  14. In vivo kinematic evaluation and design considerations related to high flexion in total knee arthroplasty.

    PubMed

    Argenson, Jean-Noël A; Scuderi, Giles R; Komistek, Richard D; Scott, W Norman; Kelly, Michael A; Aubaniac, Jean-Manuel

    2005-02-01

    In designing a posterior-stabilized total knee arthroplasty (TKA) it is preferable that when the cam engages the tibial spine the contact point of the cam move down the tibial spine. This provides greater stability in flexion by creating a greater jump distance and reduces the stress on the tibial spine. In order to eliminate edge loading of the femoral component on the posterior tibial articular surface, the posterior femoral condyles need to be extended. This provides an ideal femoral contact with the tibial articular surface during high flexion angles. To reduce extensor mechanism impingement in deep flexion, the anterior margin of the tibial articular component should be recessed. This provides clearance for the patella and patella tendon. An in vivo kinematic analysis that determined three dimensional motions of the femorotibial joint was performed during a deep knee bend using fluoroscopy for 20 subjects having a TKA designed for deep flexion. The average weight-bearing range-of-motion was 125 degrees . On average, TKA subjects experienced 4.9 degrees of normal axial rotation and all subjects experienced at least -4.4 mm of posterior femoral rollback. It is assumed that femorotibial kinematics can play a major role in patellofemoral kinematics. In this study, subjects implanted with a high-flexion TKA design experienced kinematic patterns that were similar to the normal knee. It can be hypothesized that forces acting on the patella were not substantially increased for TKA subjects compared with the normal subjects.

  15. Navigation-based femorotibial rotation pattern correlated with flexion angle after total knee arthroplasty.

    PubMed

    Ishida, Kazunari; Shibanuma, Nao; Matsumoto, Tomoyuki; Sasaki, Hiroshi; Takayama, Koji; Matsuzaki, Tokio; Tei, Katsumasa; Kuroda, Ryosuke; Kurosaka, Masahiro

    2016-01-01

    To investigate whether intraoperative kinematics obtained by navigation systems can be divided into several kinematic patterns and to assess the correlation between the intraoperative kinematics with maximum flexion angles before and after total knee arthroplasty (TKA). Fifty-four posterior-stabilised (PS) TKA implanted using an image-free navigation system were evaluated. At registration and after implantation, tibial internal rotation angles at maximum extension, 30°, 45°, 60°, 90°, and maximum flexion were collected. The rotational patterns were divided into four groups and were examined the correlation with maximum flexion before and after operation. Tibial internal rotation from 90° of flexion to maximum flexion at registration was correlated with maximum flexion angles pre- and postoperatively. The four groups showed statistically different kinematic patterns. The group with tibial external rotation up to 90° of flexion, following tibial internal rotation at registration, achieved better flexion angles, compared to those of another groups (126.7° ± 12.0°, p < 0.05). The group with tibial external rotation showed the worst flexion angles (80.0° ± 40.4°, p < 0.05). Furthermore, the group with limited extension showed worse flexion angles (111.6° ± 8.9°, p < 0.05). Navigation-based kinematic patterns found at registration predict postoperative maximum flexion angle in PS TKA. Navigation-based kinematics can be useful information during TKA surgery. Diagnostic studies, development of diagnostic criteria in a consecutive series of patients and a universally applied "gold" standard, Level II.

  16. Quantitative measurement of lower limb mechanical alignment and coronal knee laxity in early flexion.

    PubMed

    Russell, David F; Deakin, Angela H; Fogg, Quentin A; Picard, Frederic

    2014-12-01

    Non-invasive quantification of lower limb alignment using navigation technology is now possible throughout knee flexion owing to software developments. We report the precision and accuracy of a non-invasive system measuring mechanical alignment of the lower limb including coronal stress testing of the knee. Twelve cadaveric limbs were tested with a commercial invasive navigation system against the non-invasive system. Coronal mechanical femorotibial (MFT) alignment was measured with no stress, then 15 Nm varus and valgus applied moments. Measurements were recorded at 10° intervals from extension to 90° flexion. At each flexion interval, coefficient of repeatability (CR) tested precision within each system, and limits of agreement (LOA) tested agreement between the two systems. Limits for CR & LOA were set at 3° based on requirements for surgical planning and evaluation. Precision was acceptable throughout flexion in all conditions of stress using the invasive system (CR ≤ 1.9°). Precision was acceptable using the non-invasive system from extension to 50° flexion (CR ≤ 2.4°), beyond which precision was unacceptable (> 3.4°). With no coronal stress applied, agreement remained acceptable from extension to 40° (LOA ≤ 2.4°), and when 15 Nm varus or valgus stress was applied agreement was acceptable from extension to 30° (LOA ≤ 2.9°). Higher angles of knee flexion had a negative impact on precision and accuracy. The non-invasive system provides reliable quantitative data in-vitro on coronal MFT alignment and laxity in the range relevant to assessment of collateral ligament injury, pre-operative planning of arthroplasty and flexion instability following arthroplasty. In-vivo validation should be performed. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Knee flexion with quadriceps cocontraction: A new therapeutic exercise for the early stage of ACL rehabilitation.

    PubMed

    Biscarini, Andrea; Contemori, Samuele; Busti, Daniele; Botti, Fabio M; Pettorossi, Vito E

    2016-12-08

    Quadriceps strengthening exercises designed for the early phase of anterior cruciate ligament (ACL) rehabilitation should limit the anterior tibial translation developed by quadriceps contraction near full knee extension, in order to avoid excessive strain on the healing tissue. We hypothesize that knee-flexion exercises with simultaneous voluntary contraction of quadriceps (voluntary quadriceps cocontraction) can yield considerable levels of quadriceps activation while preventing the tibia from translating forward relative to the femur. Electromyographic activity in quadriceps and hamstring muscles was measured in 20 healthy males during isometric knee-flexion exercises executed near full knee extension with maximal voluntary effort of quadriceps cocontraction and external resistance (R) ranging from 0% to 60% of the 1-repetition maximum (1RM). Biomechanical modeling was applied to derive the shear (anterior/posterior) tibiofemoral force developed in each exercise condition. Isometric knee-flexion exercises with small external resistance (R=10% 1RM) and maximal voluntary effort of quadriceps cocontraction yielded a net posterior (ACL-unloading) tibial pull (P=0.005) and levels of activation of 32%, 50%, and 45% of maximum voluntary isometric contraction, for the rectus femoris, vastus medialis, and vastus lateralis, respectively. This exercise might potentially rank as one of the most appropriate quadriceps strengthening interventions in the early phase of ACL rehabilitation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Effects of knee extension constraint training on knee flexion angle and peak impact ground-reaction force.

    PubMed

    Liu, Hui; Wu, Will; Yao, Wanxiang; Spang, Jeffrey T; Creighton, R Alexander; Garrett, William E; Yu, Bing

    2014-04-01

    Low compliance with training programs is likely to be one of the major reasons for inconsistency of the data regarding the effectiveness of current anterior cruciate ligament (ACL) injury prevention programs. Training methods that reduce training time and cost could favorably influence the effectiveness of ACL injury prevention programs. A newly designed knee extension constraint training device may serve this purpose. (1) Knee extension constraint training for 4 weeks would significantly increase the knee flexion angle at the time of peak impact posterior ground-reaction force and decrease peak impact ground-reaction forces during landing of a stop-jump task and a side-cutting task, and (2) the training effects would be retained 4 weeks after completion of the training program. Controlled laboratory study. Twenty-four recreational athletes were randomly assigned to group A or B. Participants in group A played sports without wearing a knee extension constraint device for 4 weeks and then played sports while wearing the device for 4 weeks, while participants in group B underwent a reversed protocol. Both groups were tested at the beginning of week 1 and at the ends of weeks 4 and 8 without wearing the device. Knee joint angles were obtained from 3-dimensional videographic data, while ground-reaction forces were measured simultaneously using force plates. Analyses of variance were performed to determine the training effects and the retention of training effects. Participants in group A significantly increased knee flexion angles and decreased ground-reaction forces at the end of week 8 (P ≤ .012). Participants in group B significantly increased knee flexion angles and decreased ground-reaction forces at the ends of weeks 4 and 8 (P ≤ .007). However, participants in group B decreased knee flexion angles and increased ground-reaction forces at the end of week 8 in comparison with the end of week 4 (P ≤ .009). Knee extension constraint training for 4 weeks

  19. Measurement of the knee flexion angle with a Smartphone-application is precise and accurate.

    PubMed

    Jenny, Jean-Yves

    2013-05-01

    We hypothesized that the measurement of the knee flexion angle measured with a specific Smartphone application was different from the reference measurement with a navigation system designed for total knee arthroplasty (TKA). Ten consecutive patients operated on for navigation assisted TKA were selected. Six navigated and 6 Smartphone measurements of knee flexion angle were obtained for each patient. The paired difference between measurements and their correlation were analyzed. The mean paired difference between navigated and Smartphone measurements was -1.1° ± 6.8° (n.s.). There was a significant correlation between both measurements. The coherence between both measurements was good. The intra-observer and inter-observer reproducibility were good. The Smartphone application used may be considered as precise and accurate. The accuracy may be higher than other conventional measurement techniques. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. Investigating the Effects of Knee Flexion during the Eccentric Heel-Drop Exercise.

    PubMed

    Weinert-Aplin, Robert A; Bull, Anthony M J; McGregor, Alison H

    2015-06-01

    This study aimed to characterise the biomechanics of the widely practiced eccentric heel-drop exercises used in the management of Achilles tendinosis. Specifically, the aim was to quantify changes in lower limb kinematics, muscle lengths and Achilles tendon force, when performing the exercise with a flexed knee instead of an extended knee. A musculoskeletal modelling approach was used to quantify any differences between these versions of the eccentric heel drop exercises used to treat Achilles tendinosis. 19 healthy volunteers provided a group from which optical motion, forceplate and plantar pressure data were recorded while performing both the extended and flexed knee eccentric heel-drop exercises over a wooden step when barefoot or wearing running shoes. This data was used as inputs into a scaled musculoskeletal model of the lower limb. Range of ankle motion was unaffected by knee flexion. However, knee flexion was found to significantly affect lower limb kinematics, inter-segmental loads and triceps muscle lengths. Peak Achilles load was not influenced despite significantly reduced peak ankle plantarflexion moments (p < 0.001). The combination of reduced triceps lengths and greater ankle dorsiflexion, coupled with reduced ankle plantarflexion moments were used to provide a basis for previously unexplained observations regarding the effect of knee flexion on the relative loading of the triceps muscles during the eccentric heel drop exercises. This finding questions the role of the flexed knee heel drop exercise when specifically treating Achilles tendinosis. Key pointsA more dorsiflexed ankle and a flexing knee are characteristics of performing the flexed knee heel-drop eccentric exercise.Peak ankle plantarflexion moments were reduced with knee flexion, but did not reduce peak Achilles tendon force.Kinematic changes at the knee and ankle affected the triceps muscle length and resulted in a reduction in the amount of Achilles tendon work performed.A version of

  1. Investigating the Effects of Knee Flexion during the Eccentric Heel-Drop Exercise

    PubMed Central

    Weinert-Aplin, Robert A.; Bull, Anthony M.J.; McGregor, Alison H.

    2015-01-01

    This study aimed to characterise the biomechanics of the widely practiced eccentric heel-drop exercises used in the management of Achilles tendinosis. Specifically, the aim was to quantify changes in lower limb kinematics, muscle lengths and Achilles tendon force, when performing the exercise with a flexed knee instead of an extended knee. A musculoskeletal modelling approach was used to quantify any differences between these versions of the eccentric heel drop exercises used to treat Achilles tendinosis. 19 healthy volunteers provided a group from which optical motion, forceplate and plantar pressure data were recorded while performing both the extended and flexed knee eccentric heel-drop exercises over a wooden step when barefoot or wearing running shoes. This data was used as inputs into a scaled musculoskeletal model of the lower limb. Range of ankle motion was unaffected by knee flexion. However, knee flexion was found to significantly affect lower limb kinematics, inter-segmental loads and triceps muscle lengths. Peak Achilles load was not influenced despite significantly reduced peak ankle plantarflexion moments (p < 0.001). The combination of reduced triceps lengths and greater ankle dorsiflexion, coupled with reduced ankle plantarflexion moments were used to provide a basis for previously unexplained observations regarding the effect of knee flexion on the relative loading of the triceps muscles during the eccentric heel drop exercises. This finding questions the role of the flexed knee heel drop exercise when specifically treating Achilles tendinosis. Key points A more dorsiflexed ankle and a flexing knee are characteristics of performing the flexed knee heel-drop eccentric exercise. Peak ankle plantarflexion moments were reduced with knee flexion, but did not reduce peak Achilles tendon force. Kinematic changes at the knee and ankle affected the triceps muscle length and resulted in a reduction in the amount of Achilles tendon work performed. A version

  2. Absolute reliability of isokinetic knee flexion and extension measurements adopting a prone position.

    PubMed

    Ayala, F; De Ste Croix, M; Sainz de Baranda, P; Santonja, F

    2013-01-01

    The main purpose of this study was to determine the absolute and relative reliability of isokinetic peak torque (PT), angle of peak torque (APT), average power (PW) and total work (TW) for knee flexion and extension during concentric and eccentric actions measured in a prone position at 60, 180 and 240° s(-1). A total of 50 recreational athletes completed the study. PT, APT, PW and TW for concentric and eccentric knee extension and flexion were recorded at three different angular velocities (60, 180 and 240° s(-1)) on three different occasions with a 72- to 96-h rest interval between consecutive testing sessions. Absolute reliability was examined through typical percentage error (CV(TE)), percentage change in the mean (ChM) and relative reliability with intraclass correlations (ICC(3,1)). For both the knee extensor and flexor muscle groups, all strength data (except APT during knee flexion movements) demonstrated moderate absolute reliability (ChM < 3%; ICCs > 0·70; and CV(TE) < 20%) independent of the knee movement (flexion and extension), type of muscle action (concentric and eccentric) and angular velocity (60, 180 and 240° s(-1)). Therefore, the current study suggests that the CV(TE) values reported for PT (8-20%), APT (8-18%) (only during knee extension movements), PW (14-20%) and TW (12-28%) may be acceptable to detect the large changes usually observed after rehabilitation programmes, but not acceptable to examine the effect of preventative training programmes in healthy individuals.

  3. Effect of chronic knee osteoarthritis on flexion-relaxation phenomenon of the erector spinae in elderly females

    PubMed Central

    Jeong, Yeon-Gyu; Jeong, Yeon-Jae; Koo, Jung-Wan

    2016-01-01

    [Purpose] This study investigated the flexion-relaxation phenomenon of the erector spinae in elderly women with chronic knee osteoarthritis and determined whether the flexion-relaxation phenomenon can be used as a pain evaluation tool in such cases. [Subjects and Methods] Seventeen elderly females with chronic knee osteoarthritis and 13 healthy young females voluntarily participated in this study. They performed three postural positions in 15 s: trunk flexion, complete trunk flexion, and trunk extension, each for 5 s. While these positions were held, muscle activation of the thoracic and lumbar erector spinae were measured using surface electromyography. The flexion-relaxation rate was determined by dividing the values for trunk extension by those of complete trunk flexion and by dividing the values for trunk flexion by those of complete trunk flexion. [Results] According to our results, the flexion-relaxation phenomenon was different between healthy young and elderly females with chronic knee osteoarthritis. Specifically, there was a difference in the left thoracic erector spinae muscle, but not in the left and right lumbar erector spinae or right thoracic spinae muscle. [Conclusion] Our study demonstrated that the erector spinae muscle flexion-relaxation phenomenon can be used as a pain evaluation tool in elderly females with chronic knee osteoarthritis. PMID:27512244

  4. Stepwise surgical correction of instability in flexion after total knee replacement.

    PubMed

    Abdel, M P; Pulido, L; Severson, E P; Hanssen, A D

    2014-12-01

    Instability in flexion after total knee replacement (TKR) typically occurs as a result of mismatched flexion and extension gaps. The goals of this study were to identify factors leading to instability in flexion, the degree of correction, determined radiologically, required at revision surgery, and the subsequent clinical outcomes. Between 2000 and 2010, 60 TKRs in 60 patients underwent revision for instability in flexion associated with well-fixed components. There were 33 women (55%) and 27 men (45%); their mean age was 65 years (43 to 82). Radiological measurements and the Knee Society score (KSS) were used to assess outcome after revision surgery. The mean follow-up was 3.6 years (2 to 9.8). Decreased condylar offset (p < 0.001), distalisation of the joint line (p < 0.001) and increased posterior tibial slope (p < 0.001) contributed to instability in flexion and required correction at revision to regain stability. The combined mean correction of posterior condylar offset and joint line resection was 9.5 mm, and a mean of 5° of posterior tibial slope was removed. At the most recent follow-up, there was a significant improvement in the mean KSS for the knee and function (both p < 0.001), no patient reported instability and no patient underwent further surgery for instability. The following step-wise approach is recommended: reduction of tibial slope, correction of malalignment, and improvement of condylar offset. Additional joint line elevation is needed if the above steps do not equalise the flexion and extension gaps.

  5. A Textile-Based Wearable Sensing Device Designed for Monitoring the Flexion Angle of Elbow and Knee Movements

    PubMed Central

    Shyr, Tien-Wei; Shie, Jing-Wen; Jiang, Chang-Han; Li, Jung-Jen

    2014-01-01

    In this work a wearable gesture sensing device consisting of a textile strain sensor, using elastic conductive webbing, was designed for monitoring the flexion angle of elbow and knee movements. The elastic conductive webbing shows a linear response of resistance to the flexion angle. The wearable gesture sensing device was calibrated and then the flexion angle-resistance equation was established using an assembled gesture sensing apparatus with a variable resistor and a protractor. The proposed device successfully monitored the flexion angle during elbow and knee movements. PMID:24577526

  6. Influence of the posterior tibial slope on the flexion gap in total knee arthroplasty.

    PubMed

    Okazaki, Ken; Tashiro, Yasutaka; Mizu-uchi, Hideki; Hamai, Satoshi; Doi, Toshio; Iwamoto, Yukihide

    2014-08-01

    Adjusting the joint gap length to be equal in both extension and flexion is an important issue in total knee arthroplasty (TKA). It is generally acknowledged that posterior tibial slope affects the flexion gap; however, the extent to which changes in the tibial slope angle directly affect the flexion gap remains unclear. This study aimed to clarify the influence of tibial slope changes on the flexion gap in cruciate-retaining (CR) or posterior-stabilizing (PS) TKA. The flexion gap was measured using a tensor device with the femoral trial component in 20 cases each of CR- and PS-TKA. A wedge plate with a 5° inclination was placed on the tibial cut surface by switching its front-back direction to increase or decrease the tibial slope by 5°. The flexion gap after changing the tibial slope was compared to that of the neutral slope measured with a flat plate that had the same thickness as that of the wedge plate center. When the tibial slope decreased or increased by 5°, the flexion gap decreased or increased by 1.9 ± 0.6mm or 1.8 ± 0.4mm, respectively, with CR-TKA and 1.2 ± 0.4mm or 1.1 ± 0.3mm, respectively, with PS-TKA. The influence of changing the tibial slope by 5° on the flexion gap was approximately 2mm with CR-TKA and 1mm with PS-TKA. This information is useful when considering the effect of manipulating the tibial slope on the flexion gap when performing CR- or PS-TKA. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. DOES RECTUS FEMORIS TRANSFER INCREASE KNEE FLEXION DURING STANCE PHASE IN CEREBRAL PALSY?

    PubMed Central

    de Morais, Mauro César; Blumetti, Francesco Camara; Kawamura, Cátia Miyuki; Lopes, José Augusto Fernandes; Neves, Daniella Lins; Cardoso, Michelle de Oliveira

    2016-01-01

    ABSTRACT Objective: To evaluate whether distal rectus femoris transfer (DRFT) is related to postoperative increase of knee flexion during the stance phase in cerebral palsy (CP). Methods: The inclusion criteria were Gross Motor Function Classification System (GMFCS) levels I-III, kinematic criteria for stiff-knee gait at baseline, and individuals who underwent orthopaedic surgery and had gait analyses performed before and after intervention. The patients included were divided into the following two groups: NO-DRFT (133 patients), which included patients who underwent orthopaedic surgery without DRFT, and DRFT (83 patients), which included patients who underwent orthopaedic surgery that included DRFT. The primary outcome was to evaluate in each group if minimum knee flexion in stance phase (FMJFA) changed after treatment. Results: The mean FMJFA increased from 13.19° to 16.74° (p=0.003) and from 10.60° to 14.80° (p=0.001) in Groups NO-DRFT and DRFT, respectively. The post-operative FMJFA was similar between groups NO-DRFT and DRFT (p=0.534). The increase of FMJFA during the second exam (from 13.01° to 22.51°) was higher among the GMFCS III patients in the DRFT group (p<0.001). Conclusion: In this study, DRFT did not generate additional increase of knee flexion during stance phase when compared to the control group. Level of Evidence III, Retrospective Comparative Study. PMID:26997910

  8. A new hybrid spring brake orthosis for controlling hip and knee flexion in the swing phase.

    PubMed

    Gharooni, S; Heller, B; Tokhi, M O

    2001-03-01

    In this study it is proposed that active contraction of muscles might be artificially replaced by a spring brake orthosis (SBO) to provide near-natural knee and hip swing phase trajectories for gait in spinal cord injured subjects. The SBO is a new gait restoration system in which stored spring elastic energy and potential energy of limb segments are utilized to aid gait. It is also shown that hip flexion can be produced without the need for withdrawal reflex, hip flexor stimulus or any mechanical actuator at the hip. A hip flexion angle of 21 degrees was achieved by a nonimpaired subject wearing a prototype orthosis.

  9. Treatment for flexion contracture of the knee during Ilizarov reconstruction of tibia with passive knee extension splint.

    PubMed

    Kwan, M K; Penafort, R; Saw, A

    2004-12-01

    Joint stiffness is one of the complications of limb procedure. It developes as a result of failure of knee flexors to lengthen in tandem with the bone, especially when there is inadequate physical therapy to provide active and passive mobilization of the affected joint. We are reporting four patients who developed fixed flexion contracture of their knees during bone lengthening procedure for the tibia with Ilizarov external fixator. Three of them were treated for congenital pseudoarthrosis and one was for fibular hemimelia. None of them were able to visit the physiotherapist even on a weekly basis. A splint was constructed from components of Ilizarov external fixator and applied on to the existing frame to passively extend the affected knee. Patients and their family members were taught to perform this exercise regularly and eventually near complete correction were achieved. With this result, we would like to recommend the use of this "Passive Knee Extension Splint" to avoid knee flexion Contracture during limb lengthening procedures with Ilizarov external fixators.

  10. Changes in sarcomere lengths of the human vastus lateralis muscle with knee flexion measured using in vivo microendoscopy.

    PubMed

    Chen, Xuefeng; Sanchez, Gabriel N; Schnitzer, Mark J; Delp, Scott L

    2016-09-06

    Sarcomeres are the basic contractile units of muscle, and their lengths influence muscle force-generating capacity. Despite their importance, in vivo sarcomere lengths remain unknown for many human muscles. Second harmonic generation (SHG) microendoscopy is a minimally invasive technique for imaging sarcomeres in vivo and measuring their lengths. In this study, we used SHG microendoscopy to visualize sarcomeres of the human vastus lateralis, a large knee extensor muscle important for mobility, to examine how sarcomere lengths change with knee flexion and thus affect the muscle׳s force-generating capacity. We acquired in vivo sarcomere images of several muscle fibers of the resting vastus lateralis in six healthy individuals. Mean sarcomere lengths increased (p=0.031) from 2.84±0.16μm at 50° of knee flexion to 3.17±0.13μm at 110° of knee flexion. The standard deviation of sarcomere lengths among different fibers within a muscle was 0.21±0.09μm. Our results suggest that the sarcomeres of the resting vastus lateralis at 50° of knee flexion are near optimal length. At a knee flexion angle of 110° the resting sarcomeres of vastus lateralis are longer than optimal length. These results show a smaller sarcomere length change and greater conservation of force-generating capacity with knee flexion than estimated in previous studies.

  11. The effect of knee flexion and rotation on the tibial tuberosity-trochlear groove distance.

    PubMed

    Camathias, Carlo; Pagenstert, Geert; Stutz, Ulrich; Barg, Alexej; Müller-Gerbl, Magdalena; Nowakowski, Andrej M

    2016-09-01

    The purpose was to measure the effect of flexion and additional rotation of the femur relative to the tibia on the tuberosity-trochlear groove distance (TT-TG) in the same subject in 20 cadaveric knees joint. In 20 human adult cadavers, formal fixed knees (age: 81.9 years, SD 12.3; 10 female) CT scans were performed in extension and 30° of flexion as well as in neutral, maximal possible internal (IR), and external rotation (ER). On superimposed CT scan images, TT-TG was measured in each position. TT-TG measurements were correlated in all knee positions. TT-TG in full extension/neutral rotation was 7.8 mm (SD 3.4, range, 2.4-15.3). TT-TG in full extension and IR was significantly lower, and TT-TG in full extension and ER was significantly higher than in neutral rotation (5.4 ± 2.3 vs. 10.9 ± 4.8 mm; P < 0.001). IR and ER varied between 1.0°-7.6° and 0.2°-9.2°, respectively. TT-TG in 30° flexion/neutral rotation was 3.9 mm (SD 1.8, range, 1.3-7.8), which was significantly lower than in full extension and neutral rotation (P < 0.001). TT-TG in 30° flexion and IR was significantly lower, and TT-TG in 30° flexion and ER was significantly higher than values obtained in neutral rotation (2.7 ± 1.2 vs. 6.5 ± 3.4 mm; P < 0.001). IR and ER in 30° flexion varied between 0.6°-10.7° and 1.9°-13.0°, respectively. Flexion as well as rotation of the knee joint significantly alters the TT-TG. These results may have wider clinical relevance in assessing TT-TG and further decisions based on it.

  12. Variability of Measurement of Patellofemoral Indices with Knee Flexion and Quadriceps Contraction: An MRI-Based Anatomical Study

    PubMed Central

    Laugharne, Edward; Bali, Navi; Purushothamdas, Sanjay; Almallah, Faris; Kundra, Rik

    2016-01-01

    Purpose The purpose of this study was to investigate the impact of varying knee flexion and quadriceps activity on patellofemoral indices measured on magnetic resonance imaging (MRI). Materials and Methods MRI of the knee was performed in 20 patients for indications other than patellar or patellofemoral pathology. Axial and sagittal sequences were performed in full extension of the knee with the quadriceps relaxed, full extension of the knee with the quadriceps contracted, 30° flexion of the knee with the quadriceps relaxed, and 30° flexion with the quadriceps contracted. Bisect offset, patella tilt angle, Insall-Salvati ratio and Caton-Deschamps index were measured. Results With the knee flexed to 30° and quadriceps relaxed, the mean values of patellar tilt angle, bisect offset, Insall-Salvati ratio and Caton-Deschamps index were all within normal limits. With the knee extended and quadriceps contracted, the mean patellar tilt angle (normal value, <15°) was 14.6° and the bisect offset (normal value, <65%) was 65%, while the Caton-Deschamps index was 1.34 (normal range, 0.6 to 1.3). With the knee extended and quadriceps relaxed, the mean Caton-Deschamps index was 1.31. Conclusions MRI scanning of the knee in extension with the quadriceps contracted leads to elevated patellofemoral indices. MRI taken with the knee in 30° of flexion allows more reliable assessment of the patellofemoral joint and minimises the confounding effect of quadriceps contraction. PMID:27894177

  13. Monolateral external fixation for the progressive correction of neurological spastic knee flexion contracture in children

    PubMed Central

    Valero, Jose Valiente; Fernández, Pedro Doménech; Vicente-Franqueira, Javier Roca

    2007-01-01

    The purpose of this study was to report the results of the surgical treatment of spastic knee flexion contracture using tenotomy and progressive correction by external fixator–distractor devices. The study design involved a prospective observational study of 16 knees in nine patients with spastic flexion contracture greater than 30°. Treatment was indicated for both ambulatory and nonambulatory patients; and, in the latter group when sitting or personal hygiene was compromised. The average age was 11.6 years (range 10–17). Five of the patients were male and four female. There was one case of hemiplegia (11.1%), two cases of paraplegia (22.2%), and six cases of quadriplegia (66.7%). Six patients retained some walking capacity, while three had none. In all cases, distal lengthening of the hamstrings was carried out. A monolateral fixator with a gradual correction device was applied for a period of 4.8 weeks. The average follow-up was 26.6 months. The preoperative straight-leg raise was 55°. The popliteal angle was 58° preoperatively (range 30–80°), 8.5° on removal of the fixator, and 20° at the end of the follow-up. Complications: There were no superficial or deep infections, and no fractures or distal sensory–motor alterations. There was one case of arthrodiatasis of the knee (6.3%) which was resolved when the fixator was removed, and 11 cases of pin-track infection (68.7%) which were resolved with local care and oral antibiotics. To conclude, spastic knee flexion contracture can be treated gradually with monolateral external fixator with distraction devices, and with distraction modules which prevent acute stretching of the posterior neurovascular structures of the knee. PMID:18427750

  14. Defining the knee joint flexion-extension axis for purposes of quantitative gait analysis: an evaluation of methods.

    PubMed

    Schache, Anthony G; Baker, Richard; Lamoreux, Larry W

    2006-08-01

    Minimising measurement variability associated with hip axial rotation and avoiding knee joint angle cross-talk are two fundamental objectives of any method used to define the knee joint flexion-extension axis for purposes of quantitative gait analysis. The aim of this experiment was to compare three different methods of defining this axis: the knee alignment device (KAD) method, a method based on the transepicondylar axis (TEA) and an alternative numerical method (Dynamic). The former two methods are common approaches that have been applied clinically in many quantitative gait analysis laboratories; the latter is an optimisation procedure. A cohort of 20 subjects performed three different functional tasks (normal gait; squat; non-weight bearing knee flexion) on repeated occasions. Three-dimensional hip and knee angles were computed using the three alternative methods of defining the knee joint flexion-extension axis. The repeatability of hip axial rotation measurements during normal gait was found to be significantly better for the Dynamic method (p<0.01). Furthermore, both the variance in the knee varus-valgus kinematic profile and the degree of knee joint angle cross-talk were smallest for the Dynamic method across all functional tasks. The Dynamic method therefore provided superior results in comparison to the KAD and TEA-based methods and thus represents an attractive solution for orientating the knee joint flexion-extension axis for purposes of quantitative gait analysis.

  15. Knee flexion contracture treated with botulinum toxin type A in patients with haemophilia (PWH).

    PubMed

    Daffunchio, C; Caviglia, H; Nassif, J; Morettil, N; Galatro, G

    2016-01-01

    Knee flexion contracture (KFC) remains a common complication of haemoarthrosis in children and young adults with haemophilia. If the KFC is not treated properly it produces disability, postural and gait abnormalities. Evaluate the effectiveness of conservative treatment of KFC with Botulinum toxin type A (BTX-A) in PWH. Seventeen patients were treated, with 21 affected knees. Mean age was 26 years. The mean follow up was 12 months. We evaluated flexion and KFC pretreatment BTX-A and up to 12 months posttreatment. BTX-A application was in hamstring and calf muscles. To evaluate the function, a questionnaire about different activities was made, and it was checked 3, 6 and 12 months after BTX-A. According to the degree of KFC, knees were divided into 3 groups: Group 1: -10° to -30° (n = 10), Group 2: -31° to -45° (n = 6) Group 3: -46° or more (n = 5). The average KFC improved from -38° to -24°. The improvement was 14° (P < 0.001). The average KFC improvement was 9° in group 1, 17° in group 2, and 23° in group 3. There was a high correlation between the improvement in KFC and the total score of the questionnaire R = 0.77. Treatment of KFC with BTX-A improves knee-related functional activities, with the advantage of being a low-cost procedure and easy to apply. © 2015 John Wiley & Sons Ltd.

  16. The Influence of Body Position on Load Range During Isokinetic Knee Extension/Flexion

    PubMed Central

    W. Findley, Brian; E. Brown, Lee; Whitehurst, Michael; Keating, Tedd; P. Murray, Daniel; M. Gardner, Lisa

    2006-01-01

    Isokinetic range of motion (ROM) has three distinct phases: rate of velocity development (RVD), load range (LR), and deceleration (DCC). The purpose of this study was to determine if differences in isokinetic knee extension/flexion LR exist between body positions. Ten subjects (4 males and 6 females, age 29.3 ± 5.4 yrs, ht 1.71 ± 0.10 m, wt 71.9 ± 12.9 kg) volunteered to participate in the seated vs. prone investigation and nine different subjects (4 males and 5 females, age 29.5 ± 6.9 yrs, ht 1.72 ± 0.09 m, wt 69.0 ± 13.8 kg) volunteered to participate in the seated vs. supine study. Each subject completed 3 maximal reciprocal concentric/concentric repetitions of dominant knee extension/flexion on a Biodex System 2 isokinetic dynamometer at 60, 120, 180, 240 and 360 deg·sec-1 in the supine or prone and seated positions. Repeated measures ANOVA revealed that only seated flexion at 360 deg·sec-1 (57.6 ± 1.7 degrees) elicited significantly (p < 0.05) greater LR than prone (49.2 ± 2.8 degrees). No significant differences in LR extension or flexion existed at any velocity between the supine vs. seated positions. ANOVA also demonstrated differences between seated vs. prone torque, work and power at most velocities while there was no difference between seated vs. supine. LR is the only phase of an isokinetic repetition where quantifiable resistance is maintained and this data appears to support that it may not be position-dependent but position may alter traditional performance variables. Key Points Load range is the constant velocity phase where torque is collected. Load range has an inverse relationship with velocity. Load range may not be position dependent for the knee extensors or flexors. PMID:24353457

  17. Knee joint moments during high flexion movements: Timing of peak moments and the effect of safety footwear.

    PubMed

    Chong, Helen C; Tennant, Liana M; Kingston, David C; Acker, Stacey M

    2017-03-01

    (1) Characterize knee joint moments and peak knee flexion moment timing during kneeling transitions, with the intent of identifying high-risk postures. (2) Determine whether safety footwear worn by kneeling workers (construction workers, tile setters, masons, roofers) alters high flexion kneeling mechanics. Fifteen males performed high flexion kneeling transitions. Kinetics and kinematics were analyzed for differences in ascent and descent in the lead and trail legs. Mean±standard deviation peak external knee adduction and flexion moments during transitions ranged from 1.01±0.31 to 2.04±0.66% body weight times height (BW∗Ht) and from 3.33 to 12.6% BW∗Ht respectively. The lead leg experienced significantly higher adduction moments compared to the trail leg during descent, when work boots were worn (interaction, p=0.005). There was a main effect of leg (higher lead vs. trail) on the internal rotation moment in both descent (p=0.0119) and ascent (p=0.0129) phases. Peak external knee adduction moments during transitions did not exceed those exhibited during level walking, thus increased knee adduction moment magnitude is likely not a main factor in the development of knee OA in occupational kneelers. Additionally, work boots only significantly increased the adduction moment in the lead leg during descent. In cases where one knee is painful, diseased, or injured, the unaffected knee should be used as the lead leg during asymmetric bilateral kneeling. Peak flexion moments occurred at flexion angles above the maximum flexion angle exhibited during walking (approximately 60°), supporting the theory that the loading of atypical surfaces may aid disease development or progression. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Gender differences in tibio-femoral kinematics and quadriceps muscle force during weight-bearing knee flexion in vitro.

    PubMed

    Wünschel, Markus; Wülker, Nikolaus; Müller, Otto

    2013-11-01

    Females have a higher risk in terms of anterior cruciate ligament injuries during sports than males. Reasons for this fact may be different anatomy and muscle recruitment patterns leading to less protection for the cruciate- and collateral-ligaments. This in vitro study aims to evaluate gender differences in knee joint kinematics and muscle force during weight-bearing knee flexions. Thirty-four human knee specimens (17 females/17 males) were mounted on a dynamic knee simulator. Weight-bearing single-leg knee flexions were performed with different amounts of simulated body weight (BW). Gender-specific kinematics was measured with an ultrasonic motion capture system and different loading conditions were examined. Knee joint kinematics did not show significant differences regarding anteroposterior and medial-lateral movement as well as tibial varus-valgus and internal-external rotation. This applied to all simulated amounts of BW. Simulating 100 N BW in contrast to AF50 led to a significant higher quadriceps overall force in female knees from 45° to 85° of flexion in contrast to BW 50 N. In these female specimens, the quadriceps overall force was about 20 % higher than in male knees being constant in higher flexion angles. It is indicated by our results that in a squatting movement females compared with males produce higher muscle forces, suggesting an increased demand for muscular stabilization, whereas tibio-femoral kinematics was similar for both genders.

  19. Decreased flexion contracture after total knee arthroplasty using Botulinum toxin A: a randomized controlled trial.

    PubMed

    Smith, Eric B; Shafi, Karim A; Greis, Ari C; Maltenfort, Mitchell G; Chen, Antonia F

    2016-10-01

    Flexion contracture after total knee arthroplasty (TKA) can cause significant dissatisfaction. Botulinum toxin A has shown improved extension in patients with spastic flexion contractures after TKA. The purpose of this study was to evaluate whether Botulinum toxin A improves knee extension for any patient with flexion contractures following TKA. A prospective, double-blinded, randomized controlled trial was conducted. Fourteen patients (15 knees), with a flexion contracture (≥10°) one month postoperatively, were randomized to receive either Botulinum toxin A or saline placebo to the affected hamstrings. The subject, surgeon, and administering physiatrist were blinded to the treatment group throughout the study. Subject range of motion (ROM) was evaluated at 1, 6, and 12 months following injection. Differences were tested using mixed-effects regression to control for multiple measurements. The initial post-operative flexion contracture averaged 19° ± 6° in the Botulinum toxin A group and 13° ± 3° in the saline group. Injections were performed 53 and 57 days after TKA in the Botulinum toxin A and saline groups, respectively. Post-injection extension improved to an average of 8, 5, and 1 degrees for BTX and 4, 2, and 1 degrees for SAL, at 1, 6, and 12 months, respectively, compared to pre-injection extension (p < 0.0001). Improvement in knee extension at 1 year improved 18° ± 7.5° for Botulinum toxin A and 12° ± 2° for saline (p = 0.04). No complications resulted from either injection. Patients who received Botulinum toxin A or placebo were able to achieve near full extension one year after surgery. There was a statistically significant improvement in the amount of extension achieved at 1 year with Botulinum toxin A, but this may be of little clinical significance. Since achieving full extension is important for patient function and satisfaction, novel techniques to address this issue deserve special attention. I.

  20. Nucleus pulposus deformation in response to lumbar spine lateral flexion: an in vivo MRI investigation.

    PubMed

    Fazey, Peter J; Takasaki, Hiroshi; Singer, Kevin P

    2010-07-01

    Whilst there are numerous studies examining aspects of sagittal plane motion in the lumbar spine, few consider coronal plane range of motion and there are no in vivo reports of nucleus pulposus (NP) displacement in lateral flexion. This study quantified in vivo NP deformation in response to side flexion in healthy volunteers. Concomitant lateral flexion and axial rotation range were also examined to evaluate the direction and extent of NP deformation. Axial T2- and coronal T1-weighted magnetic resonance images (MRI) were obtained from 21 subjects (mean age, 24.8 years) from L1 to S1 in the neutral and left laterally flexed position. Images were evaluated for intersegmental ranges of lateral flexion and axial rotation. A novel methodology derived linear pixel samples across the width of the disc from T2 images, from which the magnitude and direction of displacement of the NP was determined. This profiling technique represented the relative hydration pattern within the disc. The NP was displaced away from the direction of lateral flexion in 95/105 discs (p < 0.001). The extent of NP displacement was associated strongly with lateral flexion at L2-3 (p < 0.01). The greatest range of lateral flexion occurred at L2-3, L3-4 and L4-5. Small intersegmental ranges of axial rotation occurred at all levels, but were not associated with NP displacement. The direction of NP deformation was highly predictable in laterally flexed healthy lumbar spines; however, the magnitude of displacement was not consistent with the degree of intersegmental lateral flexion or rotation.

  1. Analysis for Sit-to-Stand Performance According to the Angle of Knee Flexion in Individuals with Hemiparesis.

    PubMed

    Lee, Mi Young; Lee, Hae Yong

    2013-12-01

    [Purpose] Sit-to-stand (STS) is one of the important functional tasks people perform throughout the day. This study investigated whether varying angles of knee flexion affect STS patterns in individuals with hemiparesis by using a foot plantar pressure measurement system. [Methods] Fifteen stroke patients with hemiparesis participated for this study. They performed sit-to-stand with three angles of knee flexion (70°, 90°, and 110°). We measured the trajectory of the center of pressure, peak plantar pressure, and symmetry index using a Mat-scan system (Tekscan, South Boston, MA, USA). [Results] As a result, we found that there were significant differences among the three angle conditions (trajectory of center of pressure, peak plantar pressure on the affected side, and symmetry index). However, there was no significant difference in peak pressure according to the knee flexion on the unaffected side. [Conclusion] In the current study, we found that stroke patients with hemiparesis had a compensated STS pattern according to knee flexion angles. This indicates that the peak value of plantar pressure increased and that the trajectory of the center of pressure widened as the angle of knee flexion increased. We also suggest that hemiparesis patients should be more concerned about proper knee angle for symmetrical STS pattern.

  2. Identifying the Functional Flexion-extension Axis of the Knee: An In-Vivo Kinematics Study

    PubMed Central

    Yin, Li; Chen, Kaining; Guo, Lin; Cheng, Liangjun; Wang, Fuyou; Yang, Liu

    2015-01-01

    Purpose This study aimed to calculate the flexion-extension axis (FEA) of the knee through in-vivo knee kinematics data, and then compare it with two major anatomical axes of the femoral condyles: the transepicondylar axis (TEA) defined by connecting the medial sulcus and lateral prominence, and the cylinder axis (CA) defined by connecting the centers of posterior condyles. Methods The knee kinematics data of 20 healthy subjects were acquired under weight-bearing condition using bi-planar x-ray imaging and 3D-2D registration techniques. By tracking the vertical coordinate change of all points on the surface of femur during knee flexion, the FEA was determined as the line connecting the points with the least vertical shift in the medial and lateral condyles respectively. Angular deviation and distance among the TEA, CA and FEA were measured. Results The TEA-FEA angular deviation was significantly larger than that of the CA-FEA in 3D and transverse plane (3.45° vs. 1.98°, p < 0.001; 2.72° vs. 1.19°, p = 0.002), but not in the coronal plane (1.61° vs. 0.83°, p = 0.076). The TEA-FEA distance was significantly greater than that of the CA-FEA in the medial side (6.7 mm vs. 1.9 mm, p < 0.001), but not in the lateral side (3.2 mm vs. 2.0 mm, p = 0.16). Conclusion The CA is closer to the FEA compared with the TEA; it can better serve as an anatomical surrogate for the functional knee axis. PMID:26039711

  3. Soleus and vastus medialis H-reflexes: similarities and differences while standing or lying during varied knee flexion angles.

    PubMed

    Alrowayeh, Hesham N; Sabbahi, Mohamed A; Etnyre, Bruce

    2005-06-15

    The H-reflex may be a useful measure to examine the lower extremity muscles activation and inhibition following an injury. Recording the vastus medialis H-reflex amplitudes in healthy subjects while standing or lying during varied knee flexion angles may establish a reference for comparison for patients with ACL injury. Vastus medialis and soleus H-reflexes were recorded from 14 healthy subjects while lying and standing during 0, 30, 45, and 60 degrees knee flexion. EMG unit was used to electrically stimulate the tibial and femoral nerves (using 0.5 ms pulses at 0.2 pps of H-maximum amplitude) and to record four traces of the soleus and vastus medialis H-wave and one trace of the M-wave peak-to-peak amplitudes. Repeated measures three-way ANOVAs were calculated with the global alpha=0.05. Results showed that (1) the average soleus H-reflex amplitude was significantly less during standing than lying across all knee flexion conditions, (2) the average vastus medialis H-reflex amplitudes showed no measurable significant differences between neutral standing compared with lying, (3) the average vastus medialis H-reflex amplitudes were significantly greater during standing knee flexion conditions (30, 45, and 60 degrees ) than lying or neutral standing, and (4) there were no differences between soleus and vastus medialis H-reflex amplitudes during lying across all knee flexion conditions. Data from H/M ratio follow the same pattern of H-amplitude. Recording the vastus medialis H-reflex amplitude during standing and knee flexion may be a reflective of the knee function. It is more specific than the soleus H-reflex because it reflects the changes in the excitability of the quadriceps motoneurons acting directly around the knee joint.

  4. Osteotomy around young deformed knees: 38-year super-long-term follow-up to detect osteoarthritis

    PubMed Central

    2009-01-01

    Since 1969 corrective osteotomy has been performed at our institute in young patients (under 40 years) with bowlegs, knock knees and flexion or rotational deformities around the knee. Fifty-seven knees (29 left, 28 right) of 45 patients (19 boys, 26 girls) were followed-up for a period ranging from 30 to 38 years in seven patients with seven knees, from 20 to 29 years in nine patients with 11 knees, and from ten to 19 years in 29 patients with 39 knees. Supracondylar femoral osteotomy was performed on 12 knees (11 patients), high tibial osteotomy above the tibial tuberosity on eight knees (six patients) and below the tuberosity on 37 knees (28 patients). At the final follow-up (age range 42–73 years), all of the deformities were satisfactorily corrected, with no symptoms apart from nine knees, seven of which had dull pain after strenuous sport with osteophytes, etc. in the radiograph. Total knee arthroplasty was performed in the remaining two knees, at ten and 26 years, respectively, after the initial osteotomy. Osteoarthritis developed in the contralateral knee to the initial osteotomy in two patients after 34 years at age 73 and after 33 years at age 67. PMID:19777231

  5. Knee flexion contractures in institutionalized elderly: prevalence, severity, stability, and related variables.

    PubMed

    Mollinger, L A; Steffen, T M

    1993-07-01

    The purpose of this study was to document the prevalence, severity, and progression of knee flexion contractures (KFCs) in a population of institutionalized elderly and to identify relationships between knee extension and other variables. The subjects were 112 nursing home residents who exhibited a broad range of ambulation and cognitive function abilities. Data were collected initially (T1) and after a 10-month period (T2). Only 25% of the population had extension in the 0- to 5-degree (lacking full extension) range bilaterally at T1 and T2, leaving the majority of subjects with some degree of unilateral KFC. Most of the subjects with a KFC greater than 20 degrees were nonambulatory and had a significantly higher occurrence of resistance to motion than did nonambulators with a KFC of less than 20 degrees. Knee extension measurements did not change in most subjects between T1 and T2. The knees that did show a change in KFC (either an increase or a decrease) had a significantly higher occurrence of resistance to passive motion than did other knees. Compared with the subjects who gained extension, the subjects who lost extension over the study period more frequently had minimal KFC at T1, were ambulatory at T1, showed a regression in ambulation at T2, and developed resistance to motion at T2. The data confirmed significant positive correlations between degree of KFC and presence of resistance to passive knee motion, cognitive impairment, impaired ambulation, and presence of knee pain. Physical therapy assessment and intervention may be appropriate in nonambulatory nursing home residents with resistance to passive motion, residents with KFC approaching 20 degrees, and ambulatory residents with minimal KFC who develop resistance and begin to regress in ambulation. Several areas for future study are suggested.

  6. In Vivo Cervical Facet Joint Capsule Deformation During Flexion-Extension

    PubMed Central

    Anderst, William J; Lee, Joon Y; Kang, James D

    2014-01-01

    Study Design Non-randomized controlled cohort. Objective To characterize subaxial cervical facet joint kinematics and facet joint capsule (FJC) deformation during in vivo, dynamic flexion-extension. To assess the effect of single-level anterior arthrodesis on adjacent segment FJC deformation. Summary of Background Data The cervical facet joint has been identified as the most common source of neck pain and it is thought to play a role in chronic neck pain related to whiplash injury. Our current knowledge of cervical facet joint kinematics is based on cadaveric mechanical testing. Methods 14 asymptomatic controls and 9 C5-C6 arthrodesis patients performed full range of motion (ROM) flexion-extension while biplane radiographs were collected at 30 Hz. A volumetric model-based tracking process determined 3D vertebral position with sub-millimeter accuracy. FJC fibers were modeled and grouped into anterior, lateral, posterior-lateral, posterior, and posterior-medial regions. FJC fiber deformations (total, shear and compression-distraction) relative to the static position were determined for each cervical motion segment (C2-C3 through C6-C7) during flexion-extension. Results No significant differences in the rate of fiber deformation in flexion were identified among motion segments (p = .159), however, significant differences were observed among fiber regions (p < .001). Significant differences in the rate of fiber deformation in extension were identified among motion segments (p < .001) and among fiber regions (p = .001). The rate of FJC deformation in extension adjacent to the arthrodesis was 45% less than in corresponding motion segments in control subjects (p = .001). Conclusion In control subjects, facet joint capsule deformations are significantly different among vertebral levels and capsule regions when vertebrae are in an extended orientation. In a flexed orientation, FJC deformations are only different among capsule regions. Single-level anterior arthrodesis is

  7. Extension gap needs more than 1-mm laxity after implantation to avoid post-operative flexion contracture in total knee arthroplasty.

    PubMed

    Okamoto, Shigetoshi; Okazaki, Ken; Mitsuyasu, Hiroaki; Matsuda, Shuichi; Mizu-Uchi, Hideki; Hamai, Satoshi; Tashiro, Yasutaka; Iwamoto, Yukihide

    2014-12-01

    In total knee arthroplasty (TKA), a high soft-tissue tension in extension at the time of operation would cause a post-operative flexion contracture. However, how tight the extension gap should be during surgery to avoid a post-operative flexion contracture remains unclear. The hypothesis is that some laxity in the intraoperative extension gap is necessary to avoid the post-operative flexion contracture. A posterior-stabilized TKA was performed for 75 osteoarthritic knees with a varus deformity. The intraoperative extension gap was measured using a tensor device that provides the gap length and the angle between the femoral component and the tibial cut surface. The medial component gap was defined as the gap calculated by subtracting the selected thickness of the tibial component, including the polyethylene liner, from the extension gap at the medial side. Then, the patients were divided into three groups according to the medial component gap, and post-operative extension angle measured 1 year after the surgery was compared between each groups. One year post-operatively, a flexion contracture of more than 5° was found in 0/34 patients when the medial component gap was more than 1 mm, in 2/26 (8%) patients when the gap was between 0 and 1 mm, and in 3/15 (20%) patients when the gap was <0 mm. Three factors were associated significantly with the post-operative extension angle: age, preoperative extension angle, and medial component gap. The intraoperative extension gap is related to the post-operative extension angle. Surgeons should leave more than 1-mm laxity after the implantation to avoid the post-operative flexion contracture. As a clinical relevance, this study clarified the optimal extension gap to avoid the post-operative flexion contracture. Prospective comparative study, Level II.

  8. Pigmented villonodular synovitis diagnosed during revision total knee arthroplasty for flexion instability and patellar fracture.

    PubMed

    Camp, Christopher L; Yuan, Brandon J; Wood, Adam J; Lewallen, David G

    2016-03-01

    Occurring in either a localized or diffuse form, pigmented villonodular synovitis (PVNS) is a disease of unknown etiology that typically presents with insidious onset of pain, swelling, stiffness, or mechanical symptoms as a result of synovial tissue proliferation. PVNS preferentially affects large joints, most commonly the knee. Currently there is no known association with PVNS and total knee arthroplasty (TKA), and to date, there are only a few cases reported in the orthopedic literature in which PVNS was diagnosed after primary TKA. To our knowledge, this is the first case of diffuse PVNS that was discovered at the time of revision TKA for flexion instability and patellar fracture. In this patient, with no known history of PVNS, the diagnosis of diffuse PVNS was made at the time of surgery. She underwent revision TKA, partial patellectomy, and extensive synovectomy. Level of evidence: V, Case Report.

  9. Application of a vibrating device for the prevention of flexion contracture after total knee arthroplasty.

    PubMed

    Manó, Sándor; Pálinkás, Judit; Szabó, János; Nagy, Judit T; Bakó, Katalin; Csernátony, Zoltán

    2015-01-01

    Our research team developed a new, heel support-based static and vibrating complementary treatment method for the prevention of flexion contractures often arising after total knee arthroplasty. We examined the efficiency of the method performing a randomized clinical trial with 144 patients undergoing total knee replacement. Seventy-nine patients were treated for 1 week with a generally used continuous passive motion (CPM) device complemented with our new method, which was based on the application of a static and an alternating heel support. The 65 patients in the control group were treated with only a CPM device as in usual clinical practice. The femoro-tibial angle was measured immediately following surgery, and after 1 week of treatment. At the end of the 1 week treatment, the target extension angle (0° ± 5°) was achieved by significantly more patients with the new combined method. This way the elevated heel rest and the vibrating device proved to be a good adjunct treatment along with the CPM used in routine clinical practice in the first place for the prevention of flexion contractures.

  10. Dynamometric indicators of fatigue from repeated maximal concentric isokinetic plantar flexion contractions are independent of knee flexion angles and age but differ for males and females.

    PubMed

    Hébert-Losier, Kim; Holmberg, Hans-Christer

    2014-03-01

    Sex and age are reported to influence the maximal dynamometric performance of major muscle groups, inclusive of ankle plantar flexors. Knee flexion (KF) also impacts plantar flexion function from where stems use of 0° and 45° angles of KF for clinical assessment of gastrocnemius and soleus, respectively. The influence of KF, sex, and age on dynamometric indicators of plantar flexion fatigue was examined in 28 males and 28 females recruited in 2 different age groups (older and younger than 40 years). Each subject performed 50 maximal concentric isokinetic plantar flexions at 60-degree angle per·second with 0° and 45° angles of KF. Maximal voluntary isometric contractions were determined before and after isokinetic trials and maximal, minimal, and normalized linear slopes of peak power during testing. Main effects of and 2-way interactions between KF, sex, age, and order of testing were explored using mixed-effect models and stepwise regressions. At angles of 0° and 45°, the fatigue indicators in younger and older individuals were similar and not influenced by testing order. However, peak isokinetic power and isometric torque declined to greater extents in males than females and, moreover, KF exerted greater impacts on the absolute plantar flexion performance and maximal-to-minimal reduction in isokinetic power in males. Because KF wielded no pronounced effect on fatigue indicators, this test may perhaps be used over time with no major concern regarding the exact knee angle. Our findings indicate that sex, rather than age, should be considered when interpreting dynamometric indicators of fatigue from repeated maximal concentric isokinetic plantar flexions, for example, when establishing normative values or comparing outcomes.

  11. Effect of a pelvic wedge and belt on the medial and lateral hamstring muscles during knee flexion

    PubMed Central

    Yoo, Won-gyu

    2017-01-01

    [Purpose] This study developed a pelvic wedge and belt and investigated their effects on the selective activation of medial and lateral hamstring muscles during knee flexion. [Subjects and Methods] Nine adults were enrolled. The participants performed exercises without and with the pelvic wedge and belt, and the electromyographic activities of the medial and lateral hamstring muscles were recorded. [Results] The activity of the medial hamstring was increased significantly when using the pelvic wedge and belt, while the activity of the lateral hamstring did not differ significantly. [Conclusion] The pelvic wedge and belt provide a self-locked position during knee flexion in the prone position. Prone knee flexion in this position is an effective self-exercise for balanced strengthening of the medial hamstring. PMID:28210048

  12. Serial casting versus stretching technique to treat knee flexion contracture in children with spina bifida: a comparative study.

    PubMed

    Al-Oraibi, S; Tariah, Hashem Abu; Alanazi, Abdullah

    2013-01-01

    Severe knee contractures that develop soon after muscle imbalance may not improve with stretching exercises and splinting. An alternative treatment is serial casting, which has been used to promote increased range of motion. The purpose of this study was to compare the effectiveness of using serial casting and passive stretching approaches to treat knee flexion contracture in children with spina bifida. In a pre/post randomized controlled study, ten participants were included in the serial casting group, while eight participants were included in the passive stretching intervention group. The degree of knee extension was measured at baseline, immediately after intervention, and at a one-year follow-up using a standard goniometer. Both groups showed significant improvements in the degree of flexion contracture at the post-treatment evaluation and the follow-up evaluation. The serial casting group showed significant improvements in knee flexion contracture at the post-treatment evaluation, t (9)=13.4, p < 0.001, and the one-year follow-up evaluation, t (9) = 7.46, p < 0.001. The passive stretching group also showed significant improvements in knee flexion contracture at the post-treatment evaluation, t (7) =2.6, p < 0.05, and the one-year follow-up evaluation, t (7) = 3.6, p < 0.05. However, statistically significant improvements in the serial casting group compared with passive stretching group in relation to the degree of flexion contracture were found at the immediate post-treatment evaluation, F(1, 15)=246, p=0.0001, and the one-year follow-up evaluation, F (1, 15)=51.5, p=0.0001. The outcomes of this study provide the first evidence that serial casting may be a useful intervention in treating knee flexion contracture in children with spina bifida. However, further investigations into serial casting, as well as investigations into the use of serial casting with other interventions, are warranted.

  13. In-situ mechanical behavior and slackness of the anterior cruciate ligament at multiple knee flexion angles.

    PubMed

    Rachmat, H H; Janssen, D; Verkerke, G J; Diercks, R L; Verdonschot, N

    2016-03-01

    In this study the in-situ tensile behavior and slackness of the anterior cruciate ligament (ACL) was evaluated at various knee flexion angles. In four cadaveric knees the ACL was released at the tibial insertion, after which it was re-connected to a tensiometer. After pre-tensioning (10 N) the ACL in full-extension, the knee was flexed from 0° to 150° at 15° increments, during which the ACL tension was measured. At each angle the ACL was subsequently elongated and shortened under displacement control, while measuring the ACL tension. In this manner, the pre-tension or the slackness, and the mechanical response of the ACL were measured. All ACL's displayed a higher tension at low (0°-60°) and high (120°-150°) flexion angles. The ACL slackness depended on flexion angle, with the highest slackness found at 75°-90°. Additionally, the ACL stiffness also varied with flexion angle, with the ACL behaving stiffer at low and high flexion angels. In general, the ACL was stiffest at 150°, and most compliant at 90°. The results of this study contribute to understanding the mechanical behavior of the ACL in-situ, and may help tuning and validating computational knee models studying ACL function.

  14. Spontaneous Improvement of Compensatory Knee Flexion After Surgical Correction of Mismatch Between Pelvic Incidence and Lumbar Lordosis.

    PubMed

    Cheng, Xiaofei; Zhang, Feng; Wu, Jigong; Zhu, Zhenan; Dai, Kerong; Zhao, Jie

    2016-08-15

    A retrospective study. The aim of this study was to investigate the correlation between pelvic incidence (PI) and lumbar lordosis (LL) mismatch and knee flexion during standing in patients with lumbar degenerative diseases and to examine the effects of surgical correction of the PI-LL mismatch on knee flexion. Only several studies focused on knee flexion as a compensatory mechanism of the PI-LL mismatch. Little information is currently available on the effects of lumbar correction on knee flexion in patients with the PI-LL mismatch. A group of patients with lumbar degenerative diseases were divided into PI-LL match group (PI-LL ≤ 10°) and PI-LL mismatch group (PI-LL > 10°). A series of radiographic parameters and knee flexion angle (KFA) were compared between the two groups. The PI-LL mismatch group was further subdivided into operative and nonoperative group. The changes in KFA with PI-LL were examined. The PI-LL mismatch group exhibited significantly greater sagittal vertical axis (SVA), pelvic tilt (PT) and KFA, and smaller LL, thoracic kyphosis (TK), and sacral slope than the PI-LL match group. PI-LL, LL, PI, SVA, and PT were significantly correlated with KFA in the PI-LL mismatch group. From baseline to 6-month follow-up, all variables were significantly different in the operative group with the exception of PI, although there was no significant difference in any variable in the nonoperative group. The magnitude of surgical correction in the PI-LL mismatch was significantly correlated with the degree of spontaneous changes in KFA, PT, and TK. The PI-LL mismatch would contribute to compensatory knee flexion during standing in patients with lumbar degenerative disease. Surgical correction of the PI-LL mismatch could lead to a spontaneous improvement of compensatory knee flexion. The degree of improvement in knee flexion depends in part on the amount of correction in the PI-LL mismatch. 3.

  15. Influence of knee flexion angle and age on triceps surae muscle fatigue during heel raises.

    PubMed

    Hébert-Losier, Kim; Schneiders, Anthony G; García, José A; Sullivan, S John; Simoneau, Guy G

    2012-11-01

    The triceps surae (TS) muscle-tendon unit is 1 of the most commonly injured in elite and recreational athletes, with a high prevalence in middle-aged adults. The performance of maximal numbers of unilateral heel raises is used to assess, train, and rehabilitate TS endurance and conventionally prescribed in 0° knee flexion (KF) for the gastrocnemius and 45° for the soleus (SOL). However, the extent of muscle selectivity conferred through the change in the knee angle is lacking for heel raises performed to volitional fatigue. This study investigated the influence of knee angle on TS muscle fatigue during heel raises and determined whether fatigue differed between middle-aged and younger-aged adults. Forty-eight healthy individuals aged 18-25 and 35-45 years performed maximal numbers of unilateral heel raises in 0° and 45° KF. Median frequencies and linear regression slopes were calculated from the SOL, gastrocnemius medialis (GM), and gastrocnemius lateralis (GL) surface electromyographic signals. Stepwise mixed-effect regressions were used for analysis. The subjects completed an average of 45 and 48 heel raises in 0° and 45° KF, respectively. The results indicated that the 3 muscles fatigued during testing as all median frequencies decreased, and regression slopes were negative. Consistent with muscle physiology and fiber typing, fatigue was greater in the GM and GL than in the SOL (p < 0.001). However, knee angle did not influence TS muscle fatigue parameters (p = 0.814), with similar SOL, GM, and GL fatigue in 0° and 45° KF. These findings are in contrast with the traditionally described clinical use of heel raises in select knee angles for the gastrocnemius and the SOL. Furthermore, no difference in TS fatigue between the 2 age groups was able to be determined, despite the reported higher prevalence of injury in middle-aged individuals.

  16. The Mediolateral Excursion of the Meniscal Bearing during Flexion and Extension of the Knee after Medial Mobile-Bearing Unicompartmental Knee Arthroplasty.

    PubMed

    Lee, Seung-Yup; Bae, Ji-Hoon; Suh, Dong-Won; Kim, Han-Ju; Lim, Hong-Chul

    2017-02-01

    This mediolateral excursion of the bearing during knee motion is supposed to be caused by external rotation of the tibia during knee extension. However, to our knowledge, there is no published clinical evidence supporting these hypotheses. The current study aimed to evaluate the mediolateral excursion of the bearing during flexion-extension motion of the knee after medial unicompartmental knee arthroplasty (UKA). In 52 knees, varus/valgus (F-VarVal) or rotational position (F-Rot) of the femoral component and relative location of the bearing were measured with the standing anteroposterior and modified axial view, respectively. We adopted the modified axial radiographs that are simple to assess the bearing position in the flexed knee. The modified axial view showed excellent inter- and intraobserver agreements. F-Rot in the modified axial view and CT showed a high agreement in terms of validity (r = 0.98; p < 0.0001). On average, the bearing showed more medial position in extension than flexion of the knee. No correlation was found between the femoral component positions (F-VarVal and F-Rot) and mediolateral bearing excursion (p = 0.68 and 0.80, respectively). In conclusion, coronal location of bearing according to flexion-extension of the knee is not influenced by the coronal and axial alignment of the femoral component. With simple radiographic method, more medial position of the bearing according to flexion-extension of the knee. Our method could be used to assess axial rotation of the femoral component and spin-out phenomenon of the bearing following the medial UKA.

  17. Development and evaluation of a novel low-cost sensor-based knee flexion angle measurement system.

    PubMed

    Saggio, Giovanni; Quitadamo, Lucia R; Albero, Lorenzo

    2014-10-01

    Knee injuries form a large part of musculoskeletal trauma in sporting activities and the rehabilitation can require a long period, for both the patients and the specialists, to restore healthy condition. A reliable, portable, and low-cost system that could allow quick, simple, and effective measurement of knee flexion angles would greatly improve the evaluation of the rehabilitation process and the subsequent planning procedure, with meaningful reduction of recovery time and cost. A novel tool for nonstop measurements of knee flexion angles based on the adoption of an elastic sensor embedded in an easy-to-realize wearable kneepad has been proposed. We fully characterized this tool in terms of accuracy, repeatability, and reliability of measure, and validated it against the gold-standard Vicon. Our tool demonstrated good reproducibility and repeatability among testers (mean range of measures=5.82° ± 1.93°) and high accuracy (root mean square error<1.28°), together with good reliability (intraclass correlation coefficient between 0.80 and 0.91). The proposed tool demonstrates good performance, is portable, cheap, easy to use, and allows automatic measurements, so as to be a valuable system for accurate nonstop measurement of knee angles. Our sensor-based measurement system is suitable for the evaluation of the rehabilitation course after knee traumas, because it furnishes a low-cost but accurate monitor of knee flexion movements, during an amount of time as long as desired. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Effect of Posterior Tibial Slope on Flexion and Anterior-Posterior Tibial Translation in Posterior Cruciate-Retaining Total Knee Arthroplasty.

    PubMed

    Chambers, Andrew W; Wood, Addison R; Kosmopoulos, Victor; Sanchez, Hugo B; Wagner, Russell A

    2016-01-01

    Reduced posterior tibial slope (PTS) and posterior tibiofemoral translation (PTFT) in posterior cruciate-retaining (PCR) total knee arthroplasty (TKA) may result in suboptimal flexion. We evaluated the relationship between PTS, PTFT, and total knee flexion after PCR TKA in a cadaveric model. We performed a balanced PCR TKA using 9 transfemoral cadaver specimens and changed postoperative PTS in 1° increments. We measured maximal flexion and relative PTFT at maximal flexion. We determined significant changes in flexion and PTFT as a function of PTS. Findings showed an average increase in flexion of 2.3° and average PTFT increase of 1mm per degree of PTS increase when increasing PTS from 1° to 4° (P<.05). Small initial increases in PTS appear to significantly increase knee flexion and PTFT. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Pre-operative flexion contracture determines the functional outcome of haemophilic arthropathy treated with total knee arthroplasty.

    PubMed

    Atilla, B; Caglar, O; Pekmezci, M; Buyukasik, Y; Tokgozoglu, A M; Alpaslan, M

    2012-05-01

    End-stage haemophiliac arthropathy can be successfully treated with total knee arthroplasty. However, the functional results may not be as good as anticipated and certain pre-op knee characteristics may alter the functional results. The purpose of this study was to evaluate the functional outcome of TKA in haemophilic patients with specific attention to final range of motion and residual flexion contracture of the joint. Twenty-one consecutive patients were retrospectively reviewed. The average age was 34 years with an average follow-up of 5.7 years. Functional status was evaluated with Hospital for Special Surgery Knee Score. Receiving Operating Characteristics analysis was used to determine the threshold of pre-operative flexion contracture degree to avoid residual knee contracture. The range of motion was increased in 16 joints and unchanged in three joints and decreased in the remaining two. Preoperative average range of motion was 37.6°, improved to 57.1° post-operatively. The average knee score increased from 27.85 (15-30) points pre-operatively to 79.42 (12-94) points at the last follow-up. The degree of pre-operative flexion contracture was found to be a good predictor for residual flexion contracture. (Specificity: 85.7%, sensitivity: 100%, cut-off: 27.5°). Total knee replacement improves the quality of life in patients with advanced haemophilic arthropathy. Statistical analysis revealed that pre-op flexion contracture of 27.5° is an important threshold. Patients should be operated before that stage to gain maximum benefit with minimal gait abnormalities. © 2011 Blackwell Publishing Ltd.

  20. Contributions of knee swing initiation and ankle plantar flexion to the walking mechanics of amputees using a powered prosthesis.

    PubMed

    Ingraham, Kimberly A; Fey, Nicholas P; Simon, Ann M; Hargrove, Levi J

    2014-01-01

    Recently developed powered prostheses are capable of producing near-physiological joint torque at the knee and/or ankle joints. Based on previous studies of biological joint impedance and the mechanics of able-bodied gait, an impedance-based controller has been developed for a powered knee and ankle prosthesis that integrates knee swing initiation and powered plantar flexion in late stance with increasing ankle stiffness throughout stance. In this study, five prosthesis configuration conditions were tested to investigate the individual contributions of each sub-strategy to the overall walking mechanics of four unilateral transfemoral amputees as they completed a clinical 10-m walk test using a powered knee and ankle prosthesis. The baseline condition featured constant ankle stiffness and no swing initiation or powered plantar flexion. The four remaining conditions featured knee swing initiation alone (SI) or in combination with powered plantar flexion (SI+PF), increasing ankle stiffness (SI+IK), or both (SI+PF+IK). Self-selected walking speed did not significantly change between conditions, although subjects tended to walk the slowest in the baseline condition compared to conditions with swing initiation. The addition of powered plantar flexion resulted in significantly higher ankle power generation in late stance irrespective of ankle stiffness. The inclusion of swing initiation resulted in a significantly more flexed knee at toe off and a significantly higher average extensor knee torque following toe off. Identifying individual contributions of intrinsic control strategies to prosthesis biomechanics could help inform the refinement of impedance-based prosthesis controllers and simplify future designs of prostheses and lower-limb assistive devices alike.

  1. Abdominal Bracing Increases Ground Reaction Forces and Reduces Knee and Hip Flexion During Landing.

    PubMed

    Campbell, Amity; Kemp-Smith, Kevin; O'Sullivan, Peter; Straker, Leon

    2016-04-01

    Controlled laboratory study. Abdominal bracing (AB) is a widely advocated method of increasing spine stability, yet the influence of AB on the execution of sporting movements has not been quantified. Landing is a common task during sporting endeavors; therefore, investigating the effect of performing AB during a drop-landing task is relevant. To quantify the effect of AB on kinematics (ankle, knee, hip, and regional lumbar spine peak flexion angles) and peak vertical ground reaction force (vGRF) during a drop-landing task. Sixteen healthy adults (7 female, 9 male; mean ± SD age, 27 ± 7 years; height, 170.6 ± 8.1 cm; mass, 68.0 ± 11.3 kg) were assessed using 3-D motion analysis, electromyography (EMG), and a force platform while performing a drop-landing task with and without AB. Abdominal bracing was achieved with the assistance of real-time internal oblique EMG feedback. Lower-limb and regional lumbar spine kinematics, peak vGRF, and normalized EMG of the left and right internal obliques and lumbar multifidus were quantified. Paired-samples t tests were used to compare variables between the AB and no-AB conditions. Abdominal bracing resulted in significantly reduced knee and hip flexion and increased peak vGRF during landing. No differences in lumbar multifidus EMG or lumbar spine kinematics were observed. Abdominal bracing reduces impact attenuation during landing. These altered biomechanics may have implications for lower-limb and spinal injury risk during dynamic tasks.

  2. Peak triceps surae muscle activity is not specific to knee flexion angles during MVIC.

    PubMed

    Hébert-Losier, Kim; Schneiders, Anthony G; García, José A; Sullivan, S John; Simoneau, Guy G

    2011-10-01

    There is limited research on peak activity of the separate triceps surae muscles in select knee flexion (KF) positions during a maximum voluntary isometric contraction (MVIC) used to normalize EMG signals. The aim of this study was to determine how frequent peak activity occurred during an MVIC for soleus (SOL), gastrocnemius medialis (GM), and gastrocnemius lateralis (GL) in select KF positions, and if these peaks were recorded in similar KF positions. Forty-eight healthy individuals performed unilateral plantar-flexion MVIC in standing with 0°KF and 45°KF, and in sitting with 90°KF. Surface EMG of SOL, GM, and GL were collected and processed in 250 ms epochs to determine peak root-mean-square amplitude. Peak activity was most frequently captured in standing and rarely in sitting, with no position selective to SOL, GM or GL activity. Peak GM and GL activity was more frequent in 0°KF than 45°KF, and more often in similar KF positions than not. Peak SOL activity was just as likely in 45°KF as 0°KF, and more in positions similar to GM, but not GL. The EMG amplitudes were at least 20% greater in positions that captured peak activity over those that did not. The overall findings support performing an MVIC in more than one KF position to normalize triceps surae EMG. It is emphasized that no KF position is selective to SOL, GM, or GL alone.

  3. Larger plantar flexion torque variability implies less stable balance in the young: an association affected by knee position.

    PubMed

    Mello, Emanuele Moraes; Magalhães, Fernando Henrique; Kohn, André Fabio

    2013-12-01

    The present study examined the association between plantar flexion torque variability during isolated isometric contractions and during quiet bipedal standing. For plantar flexion torque measurements in quiet stance (QS), subjects stood still over a force plate. The mean plantar flexion torque level exerted by each subject in QS (divided by 2 to give the torque due to a single leg) served as the target torque level for right leg force-matching tasks in extended knee (KE) and flexed knee (KF) conditions. Muscle activation levels (EMG amplitudes) of the triceps surae and mean, standard deviation and coefficient of variation of plantar flexion torque were computed from signals acquired during periods with and without visual feedback. No significant correlations were found between EMG amplitudes and torque variability, regardless of the condition and muscle being analyzed. A significant correlation was found between torque variability in QS and KE, whereas no significant correlation was found between torque variability in QS and KF, regardless of vision availability. Therefore, torque variability measured in a controlled extended knee plantar flexion contraction is a predictor of torque variability in the anterior-posterior direction when the subjects are in quiet standing. In other words, larger plantar flexion torque variability in KE (but not in KF) implies less stable balance. The mechanisms underlying the findings above are probably associated with the similar proprioceptive feedback from the triceps surae in QS and KE and poorer proprioceptive feedback from the triceps surae in KF due to the slackening of the gastrocnemii. An additional putative mechanism includes the different torque contributions of each component of the triceps surae in the two knee angles. From a clinical and research standpoint, it would be advantageous to be able to estimate changes in balance ability by means of simple measurements of torque variability in a force matching task.

  4. Correlation of isokinetic and novel hand-held dynamometry measures of knee flexion and extension strength testing.

    PubMed

    Whiteley, Rod; Jacobsen, Phillip; Prior, Simon; Skazalski, Christopher; Otten, Roald; Johnson, Amanda

    2012-09-01

    Describe inter-rater reliability of, and correlations between a novel method of isometric knee extension and flexion and eccentric knee flexion strength using hand-held dynamometry and isokinetic testing for flexion/extension in the knees of athletic participants. Document strength data normalized to the individual's limb muscle mass. Observational and reliability study. Inter-rater reliability for each of the hand-held dynamometry measures was established in both legs of 10 volunteers (6 male). During routine annual screening, 216 male professional football (soccer) players were examined using these same measures in addition to performing an isokinetic evaluation of knee flexion and extension strength. Intra-class correlation coefficients for inter-rater reliability, Pearson r correlations between hand-held dynamometry and isokinetic dynamometry were calculated. Peak torque, peak torque normalized to: body weight; lean body mass; and lean limb mass were documented. Excellent inter-rater reliability was demonstrated with intra-class correlation₂,₁ values of 0.90, 0.91, and 0.96, for the eccentric hamstrings, isometric hamstrings, and isometric quadriceps measures respectively. Medium to high correlations (r=0.322-0.617) which were all significant (p<0.001) were found for the comparisons between the hand-held dynamometry and isokinetic measures. We present 3 novel and reliable methods of examining knee flexion and extension strength using hand-held dynamometry which require less skill and strength on the part of the examiner than previous measures. Correlations between these measures and isokinetic dynamometry are documented. The hand-held dynamometry examinations took less than 4 min per player to conduct and may be useful in clinical practice where isokinetic examination can be difficult to implement. Copyright © 2012 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  5. A Multibody Knee Model Corroborates Subject-Specific Experimental Measurements of Low Ligament Forces and Kinematic Coupling During Passive Flexion.

    PubMed

    Kia, Mohammad; Schafer, Kevin; Lipman, Joseph; Cross, Michael; Mayman, David; Pearle, Andrew; Wickiewicz, Thomas; Imhauser, Carl

    2016-05-01

    A multibody model of the knee was developed and the predicted ligament forces and kinematics during passive flexion corroborated subject-specific measurements obtained from a human cadaveric knee that was tested using a robotic manipulator. The model incorporated a novel strategy to estimate the slack length of ligament fibers based on experimentally measured ligament forces at full extension and included multifiber representations for the cruciates. The model captured experimentally measured ligament forces (≤ 5.7 N root mean square (RMS) difference), coupled internal rotation (≤ 1.6 deg RMS difference), and coupled anterior translation (≤ 0.4 mm RMS difference) through 130 deg of passive flexion. This integrated framework of model and experiment improves our understanding of how passive structures, such as ligaments and articular geometries, interact to generate knee kinematics and ligament forces.

  6. Blocking collagen fibril formation in injured knees reduces flexion contracture in a rabbit model.

    PubMed

    Steplewski, Andrzej; Fertala, Jolanta; Beredjiklian, Pedro K; Abboud, Joseph A; Wang, Mark L Y; Namdari, Surena; Barlow, Jonathan; Rivlin, Michael; Arnold, William V; Kostas, James; Hou, Cheryl; Fertala, Andrzej

    2017-05-01

    Post-traumatic joint contracture is a frequent orthopaedic complication that limits the movement of injured joints, thereby severely impairing affected patients. Non-surgical and surgical treatments for joint contracture often fail to improve the range of motion. In this study, we tested a hypothesis that limiting the formation of collagen-rich tissue in the capsules of injured joints would reduce the consequences of the fibrotic response and improve joint mobility. We targeted the formation of collagen fibrils, the main component of fibrotic deposits formed within the tissues of injured joints, by employing a relevant rabbit model to test the utility of a custom-engineered antibody. The antibody was delivered directly to the cavities of injured knees in order to block the formation of collagen fibrils produced in response to injury. In comparison to the non-treated control, mechanical tests of the antibody-treated knees demonstrated a significant reduction of flexion contracture. Detailed microscopic and biochemical studies verified that this reduction resulted from the antibody-mediated blocking of the assembly of collagen fibrils. These findings indicate that extracellular processes associated with excessive formation of fibrotic tissue represent a valid target for limiting post-traumatic joint stiffness. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1038-1046, 2017. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  7. The Effect of Tibial Rotation on the Contribution of Medial and Lateral Hamstrings During Isometric Knee Flexion

    PubMed Central

    Jónasson, Gunnlaugur; Helgason, Andri; Ingvarsson, Þorsteinn; Kristjánsson, Arnar Már; Briem, Kristín

    2015-01-01

    Background: Selective atrophy of hamstring components may result from muscle strain or graft harvesting for anterior cruciate ligament reconstruction. Assessment and rehabilitation that specifically targets medial (MH) or lateral (LH) hamstring components may improve patient outcomes. The purpose of this study was to evaluate effects of volitional tibial rotation medially (MR) versus laterally (LR) on activation levels of MH versus LH and strength measures during isometric testing of knee flexors. Hypothesis: Muscle activation of MH and LH during knee flexor strength testing will be augmented when coupled with MR and LR of the tibia, respectively, without affecting knee flexor strength measures. Study Design: Cross-sectional laboratory study. Level of Evidence: Level 3. Methods: Surface electrodes were used to record neuromuscular activity from MH and LH of the right lower limb in 40 healthy young men and women during isometric knee flexor strength testing at 40° of knee flexion, where participants maintained concurrent volitional MR or LR of the tibia. Statistical analyses of variance included general linear models for repeated measures. Results: A significant interaction was found for tibial rotation and hamstring component variables (P < 0.01). When isometric knee flexion was coupled with LR, normalized activation levels were similar for MH and LH. When performed with MR, a significant drop in LH activation led to dissimilar activation levels of the 2 components. Significantly greater strength measures were found when isometric knee flexion was performed with concurrent LR of the tibia (P < 0.01). Both sexes demonstrated the same rotation-dependent differences. Conclusion: Coupling tibial rotation with knee flexor activities primarily affects the LH component. Clinical Relevance: Strategies involving volitional tibial rotation may be considered for specific assessment/rehabilitation of the MH or LH component. PMID:26721286

  8. The Effect of Tibial Rotation on the Contribution of Medial and Lateral Hamstrings During Isometric Knee Flexion.

    PubMed

    Jónasson, Gunnlaugur; Helgason, Andri; Ingvarsson, Þorsteinn; Kristjánsson, Arnar Már; Briem, Kristín

    2016-01-01

    Selective atrophy of hamstring components may result from muscle strain or graft harvesting for anterior cruciate ligament reconstruction. Assessment and rehabilitation that specifically targets medial (MH) or lateral (LH) hamstring components may improve patient outcomes. The purpose of this study was to evaluate effects of volitional tibial rotation medially (MR) versus laterally (LR) on activation levels of MH versus LH and strength measures during isometric testing of knee flexors. Muscle activation of MH and LH during knee flexor strength testing will be augmented when coupled with MR and LR of the tibia, respectively, without affecting knee flexor strength measures. Cross-sectional laboratory study. Level 3. Surface electrodes were used to record neuromuscular activity from MH and LH of the right lower limb in 40 healthy young men and women during isometric knee flexor strength testing at 40° of knee flexion, where participants maintained concurrent volitional MR or LR of the tibia. Statistical analyses of variance included general linear models for repeated measures. A significant interaction was found for tibial rotation and hamstring component variables (P < 0.01). When isometric knee flexion was coupled with LR, normalized activation levels were similar for MH and LH. When performed with MR, a significant drop in LH activation led to dissimilar activation levels of the 2 components. Significantly greater strength measures were found when isometric knee flexion was performed with concurrent LR of the tibia (P < 0.01). Both sexes demonstrated the same rotation-dependent differences. Coupling tibial rotation with knee flexor activities primarily affects the LH component. Strategies involving volitional tibial rotation may be considered for specific assessment/rehabilitation of the MH or LH component.

  9. Comparison of Mobile-Bearing and Fixed-Bearing Designs in High Flexion Total Knee Arthroplasty: Using a Navigation System

    PubMed Central

    Kim, Tae Wan; Park, Shi Hwan

    2012-01-01

    Purpose We compared and analyzed the short term results of high flexion total knee arthroplasty (TKA) with mobile-bearing and fixed bearing designs. Materials and Methods We studied 32 patients that had undergone TKA with LPS-Flex Mobile and 34 patients with LPS-Flex Fixed using an electromagnetic navigation system between January 2010 and June 2010, and were followed up for at least 1 year. Results Knee Society Functional Score (KSFS) and Knee Society Knee Score (KSKS) of the mobile-bearing group were 94.5 and 93.8 points, respectively, and were 48.2 and 45.3 points preoperatively, whereas those of the fixed-bearing group were 95.1 and 94.2 points, respectively, and were 49.5 and 46.9 points preoperatively. Postoperative mechanical axis deviation and implant position of the femoral and tibial component both on the coronal and sigittal planes showed no significant differences between the two groups. Range of motion (ROM) and maximal flexion angle (MFA) of the knee joint also showed no significant differences between the two groups. The possibility of crossed-legged sitting and kneeling position also showed no significant differences between the two groups. Conclusions Clinical and radiologic parameters, ROM and MFA of knee joints showed no significant differences in both the groups, but long term follow-up results may be necessary, including survival rate. PMID:22570849

  10. Analysis of Impingement between Patella Bone and Bearing Post in Cruciate-Substituting High-Flexion Total Knee Arthroplasty.

    PubMed

    Chon, Jegyun; Lee, Bongju; Shin, Sangyeop; Jang, Gunil; Jeon, Taehyeon

    2016-06-01

    We investigated the causes of impingement between the patella bone and the bearing post during high flexion in cruciate-substituting total knee arthroplasty and proposed a treatment strategy. This prospective cohort study included 218 cases that had undergone cruciate-substituting total knee arthroplasty from February 2014 to January 2015; a single surgeon performed the operation using the same method without patellar resurfacing in all patients. In these patients, the occurrence of impingement was determined by performing more than 120° high knee flexion after inserting a bearing perioperatively. The incidence of impingement was significantly associated with bearing design, femoral implant size, patella bone length, and patella inferior pole angle (p < 0.05). The impingement was resolved by resection of the lower articular side of the patella bone. In the cruciate-substituting high-flexion total knee arthroplasty, impingement between the patella bone and bearing post was more common in patients with mobile bearing, small-size femoral component, and a long patella or a large inferior pole angle. In cases of intraoperative impingement between the patella bone and the bearing post, resection in the lower portion of the patella prevented impingement of the bearing with soft tissue or the patella by widening the space between the patella and the bearing post, which in turn prevented postoperative reduction in range of motion.

  11. Analysis of Impingement between Patella Bone and Bearing Post in Cruciate-Substituting High-Flexion Total Knee Arthroplasty

    PubMed Central

    Chon, Jegyun; Shin, Sangyeop; Jang, Gunil; Jeon, Taehyeon

    2016-01-01

    Background We investigated the causes of impingement between the patella bone and the bearing post during high flexion in cruciate-substituting total knee arthroplasty and proposed a treatment strategy. Methods This prospective cohort study included 218 cases that had undergone cruciate-substituting total knee arthroplasty from February 2014 to January 2015; a single surgeon performed the operation using the same method without patellar resurfacing in all patients. Results In these patients, the occurrence of impingement was determined by performing more than 120° high knee flexion after inserting a bearing perioperatively. The incidence of impingement was significantly associated with bearing design, femoral implant size, patella bone length, and patella inferior pole angle (p < 0.05). The impingement was resolved by resection of the lower articular side of the patella bone. Conclusions In the cruciate-substituting high-flexion total knee arthroplasty, impingement between the patella bone and bearing post was more common in patients with mobile bearing, small-size femoral component, and a long patella or a large inferior pole angle. In cases of intraoperative impingement between the patella bone and the bearing post, resection in the lower portion of the patella prevented impingement of the bearing with soft tissue or the patella by widening the space between the patella and the bearing post, which in turn prevented postoperative reduction in range of motion. PMID:27247740

  12. Quadriceps and patellar tendon pie-crusting as a treatment for limited flexion in total knee arthroplasty.

    PubMed

    Burge, J Ross; Sanchez, Hugo B; Wagner, Russell A

    2014-04-01

    The pie-crusting method of ligament and tendon lengthening has been used successfully in various tissues but is not reported in the literature as an option for patellar or quadriceps tendons to address flexion limitation. Our case report discusses a patient with longstanding flexion limitation who underwent primary total knee arthroplasty. The report reviews the literature on intraoperative treatments, which primarily pertains to the condition of patella baja, and demonstrates that the pie-crusting technique should be included as a treatment option for a tight extensor mechanism while having some advantages over tibial tubercle osteotomy or Z-plasty.

  13. Influence of knee flexion angle and age on triceps surae muscle activity during heel raises.

    PubMed

    Hébert-Losier, Kim; Schneiders, Anthony G; García, José A; Sullivan, S John; Simoneau, Guy G

    2012-11-01

    Triceps surae and Achilles tendon injuries are frequent in sports medicine, particularly in middle-aged adults. Muscle imbalances and weakness are suggested to be involved in the etiology of these conditions, with heel-raise testing often used to assess and treat triceps surae (TS) injuries. Although heel raises are recommended with the knee straight for gastrocnemius and bent for soleus (SOL), the extent of muscle selectivity in these positions is not clear. This study aimed to determine the influence of knee angle and age on TS muscle activity during heel raises. Forty-eight healthy men and women were recruited from a younger-aged (18-25 years) and middle-aged (35-45 years) population. All the subjects performed unilateral heel raises in 0° and 45° knee flexion (KF). Soleus, gastrocnemius medialis (GM) and gastrocnemius lateralis (GL) surface electromyography signals were processed to compute root-mean-square amplitudes, and data were analyzed using mixed-effects models and stepwise regression. The mean TS activity during heel raises was 23% of maximum voluntary isometric contraction when performed in 0° KF and 21% when in 45°. Amplitudes were significantly different between TS muscles (p < 0.001) and KF angles (p < 0.001), with a significant interaction (p < 0.001). However, the age of the population did not influence the results (p = 0.193). The findings demonstrate that SOL activity was 4% greater when tested in 45° compared with 0° KF and 5% lower in the GM and GL. The results are consistent with the recommended use of heel raises in select knee positions for assessing, training, and rehabilitating the SOL and gastrocnemius muscles; however, the 4-5% documented change in activity might not be enough to significantly influence clinical outcome measures or muscle-specific benefits. Contrary to expectations, TS activity did not distinguish between middle-aged and younger-aged adults, despite the higher injury prevalence in middle age.

  14. Reciprocal activation of gastrocnemius and soleus motor units is associated with fascicle length change during knee flexion

    PubMed Central

    Lauber, Benedikt; Lichtwark, Glen A.; Cresswell, Andrew G.

    2014-01-01

    Abstract While medial gastrocnemius (MG) and soleus (SOL) are considered synergists, they are anatomically exclusive in that SOL crosses only the ankle, while MG crosses both the knee and ankle. Due to the force‐length properties of both active and passive structures, activation of SOL and MG must be constantly regulated to provide the required joint torques for any planned movement. As such, the aim of this study was to investigate the neural regulation of MG and SOL when independently changing their length by changing only the knee joint angle, thus exclusively altering the length of MG fibers. MG and SOL motor units (MU) were recorded intramuscularly along with ultrasound imaging of MG and SOL fascicle lengths, while moving the knee through 60° of rotation and maintaining a low level of voluntary plantar flexor torque. The results showed a reciprocal activation of MG and SOL as the knee was moved into flexion and extension. A clear reduction in MG MU firing rates occurred as the knee was flexed (MG fascicles shortening), with de‐recruitment of most MG MU occurring at close to full knee flexion. A concomitant increase in SOL MU activity was observed while no change in the length of its fascicles was found. The opposite effects were found when the knee was moved into extension. A strong correlation (ICC = 0.78) was found between the fascicle length at which MG MUs were de‐recruited and subsequently re‐recruited. This was stronger than the relationship of de‐recruitment and re‐recruitment with knee angle (ICC = 0.52), indicating that in this instance, muscle fascicle length rather than joint angle is more influential in regulating MG recruitment. Such a reciprocal arrangement like the one presented here for SOL and MG is essential for human voluntary movements such as walking or cycling. PMID:24920126

  15. Bi-cruciate substituting total knee arthroplasty improved medio-lateral instability in mid-flexion range.

    PubMed

    Kaneko, Takao; Kono, Norihiko; Mochizuki, Yuta; Hada, Masaru; Toyoda, Shinya; Musha, Yoshiro

    2017-03-01

    Appropriate medio-lateral (ML) stability is an important factor of good clinical outcome following total knee arthroplasty (TKA). We hypothesized that a newly introduced Bi-Cruciate Stabilized substituting (BCS) prosthesis reduces the medio-lateral instability in mid-flexion range. The purpose of this study was to measure the ML stability (varus ligament balance) using a new tensor device after implantation of BCS TKA and to analysis the association between varus ligament balance and clinical results after TKA. We evaluated 33 patients who underwent 39 Journey. 2. BCS TKA using the measured resection technique. We measured the gaps after implantation from extension to full flexion with reduced patella by constant distraction force with 120N. The varus ligament balance gap was defined as the gap calculated by subtracting from Lateral to medial component gap. The clinical results at 2years after operation was compared with intraoperative varus ligament balance. Varus ligament balance showed its maximum gap at full knee extension and 120° flexion. Varus ligament balance at 30°, 60° and 90° of flexion were significant differences in the varus ligament balance at full extension. (* p < 0.05). The varus ligament balance gap was negatively corrected with postoperative 2011 Knee society score (patient's satisfaction) (r = 0.661, p = 0.001). The most important findings of the present study are that BCS TKA can reduces the ML instability in mid-flexion range, and improve simultaneously the patient's satisfaction. Therapeutic study, Level III.

  16. Early clinical results of a high-flexion, posterior-stabilized, mobile-bearing total knee arthroplasty: a US investigational device exemption trial.

    PubMed

    Scuderi, Giles R; Hedden, David R; Maltry, John A; Traina, Steven M; Sheinkop, Mitchell B; Hartzband, Mark A

    2012-03-01

    Between May 2001 and June 2004, 388 total knee arthroplasty cases were enrolled in a prospective, randomized, multicenter investigational device exemption trial. Patients received either the investigational high-flexion mobile-bearing knee or a fixed-bearing control. At 2 to 4 years of follow-up, results in 293 patients with degenerative joint disease were compared using Knee Society Assessment and Function scores, radiographic results, complications analysis, and survival estimates. The mobile-bearing and fixed-bearing groups demonstrated similar, significant improvement over preoperative assessments in Knee Scores, maximum flexion, and range of motion. One mobile-bearing arthroplasty required revision. Radiographic results were unremarkable, and implant-related complications were rare in both groups. At this early follow-up, the investigational high-flexion mobile-bearing knee and its fixed-bearing counterpart demonstrated comparable, effective performance. Copyright © 2012 Elsevier Inc. All rights reserved.

  17. Genome wide gene expression analysis of the posterior capsule in patients with osteoarthritis and knee flexion contracture.

    PubMed

    Campbell, Thomas Mark; Trudel, Guy; Wong, Kayleigh Kristin; Laneuville, Odette

    2014-11-01

    Knee flexion contractures (KFC) are limitations in the ability to fully extend the knee joint. In people with knee osteoarthritis (OA), KFC are common, impair function, and worsen outcomes after arthroplasty. In KFC, the posterior knee capsule is believed to play a key role, but the pathophysiology remains poorly understood. We sought to identify gene expression differences in the posterior knee capsule of patients with OA with and without KFC. Capsule tissue was obtained from the knees of 12 subjects diagnosed with advanced-stage OA at the time of knee arthroplasty surgery. The presence or absence of KFC allocated patients into 2 groups using a case-control design. Genomewide capsular gene expression was compared between the 2 patient groups. Confirmation of differential expression of the corresponding proteins was performed by immunohistochemistry on tissue sections. There were no significant demographic differences between the patients with OA with KFC and without KFC save for reduced extension in their surgical knee (p<0.01). KFC patients showed a 6.4-fold decrease in CSN1S1 (p=0.017) gene expression and a 3.7-, 2.0-, and 2.6-fold increase in CHAD, Sox9, and Cyr61 gene expression, respectively (p=0.001, 0.004, 0.001, respectively). There were corresponding increases in protein levels for chondroadherin, sex determining region Y-box 9, and casein alphaS1 (all p<0.05). Functional analysis of the differentially expressed genes indicated a strong association with pathways related to the extracellular matrix and to tissue fibrosis. Posterior capsules in endstage OA knees with KFC exhibited differential expression of 4 genes all previously documented to be associated with tissue fibrosis.

  18. The effect of velocity and gender on load range during knee extension and flexion exercise on an isokinetic device.

    PubMed

    Brown, L E; Whitehurst, M; Gilbert, R; Buchalter, D N

    1995-02-01

    Limb acceleration and deceleration during exercise on an isokinetic device encounter no machine-offered resistance. The purpose of this study was to quantify the relationship between velocity and range of motion that is sustained at a predetermined isokinetic velocity, termed load range, during concentric knee extension and flexion exercise. Nine male and nine female subjects performed three maximal concentric reciprocal knee extension and flexion repetitions at 60, 120, 180, 240, 360, and 450 degrees/sec. Extension and flexion results revealed a significant (p < 0.05) increase in acceleration and deceleration range of motion while load range significantly decreased with increasing velocity. Males exhibited greater load range and less acceleration range of motion than females at 240, 360, and 450 degrees/sec, while deceleration range of motion was not different between genders at any speed. These results demonstrate an inverse relationship between isokinetic velocity and load range and suggest a need to carefully consider velocity selection when performing exercise on an isokinetic device.

  19. The functional anatomy of the iliotibial band during flexion and extension of the knee: implications for understanding iliotibial band syndrome.

    PubMed

    Fairclough, John; Hayashi, Koji; Toumi, Hechmi; Lyons, Kathleen; Bydder, Graeme; Phillips, Nicola; Best, Thomas M; Benjamin, Mike

    2006-03-01

    Iliotibial band (ITB) syndrome is a common overuse injury in runners and cyclists. It is regarded as a friction syndrome where the ITB rubs against (and 'rolls over') the lateral femoral epicondyle. Here, we re-evaluate the clinical anatomy of the region to challenge the view that the ITB moves antero-posteriorly over the epicondyle. Gross anatomical and microscopical studies were conducted on the distal portion of the ITB in 15 cadavers. This was complemented by magnetic resonance (MR) imaging of six asymptomatic volunteers and studies of two athletes with acute ITB syndrome. In all cadavers, the ITB was anchored to the distal femur by fibrous strands, associated with a layer of richly innervated and vascularized fat. In no cadaver, volunteer or patient was a bursa seen. The MR scans showed that the ITB was compressed against the epicondyle at 30 degrees of knee flexion as a consequence of tibial internal rotation, but moved laterally in extension. MR signal changes in the patients with ITB syndrome were present in the region occupied by fat, deep to the ITB. The ITB is prevented from rolling over the epicondyle by its femoral anchorage and because it is a part of the fascia lata. We suggest that it creates the illusion of movement, because of changing tension in its anterior and posterior fibres during knee flexion. Thus, on anatomical grounds, ITB overuse injuries may be more likely to be associated with fat compression beneath the tract, rather than with repetitive friction as the knee flexes and extends.

  20. Correction of angular deformities of the knee by percutaneous hemiepiphysiodesis.

    PubMed

    Inan, Muharrem; Chan, Gilbert; Bowen, J Richard

    2007-03-01

    Predicting patients' remaining angular growth and timing for hemiepiphysiodesis are crucial for correcting coronal plane knee deformities in children. We asked whether the Angular Deformity Versus Growth Remaining Chart predicted correction of coronal angular deformities of the knee in children. Serial orthoroentgenograms and the predictive chart were used to time percutaneous hemiepiphysiodesis, and the children were followed until skeletal maturity. Twenty-five consecutive children (35 extremities) with a mean skeletal age of 13 years (range, 9.6-16 years) had percutaneous hemiepiphysiodeses as described by Bowen and Johnson, and were followed up until skeletal maturity. At skeletal maturity, correction of varus and valgus coronal plane deformities were within 2 degrees (range, 0 degrees - 6 degrees) of the predicted value. The maximum limb-length discrepancy resulting from the procedure was 1.5 cm. The only complication was failure of a physeal bar formation hemiepiphysiodesis; this was treated successfully with a repeat percutaneous hemiepiphysiodesis. The percutaneous hemiepiphysiodesis is effective and has a low complication rate. Angular correction and timing for hemiepiphysiodesis can be predicted by using the Angular Deformity Versus Growth Remaining Chart in children with coronal plain knee deformities.

  1. Patellar clunk syndrome in a current high flexion total knee design.

    PubMed

    Agarwala, Sanjay R; Mohrir, Ganesh S; Patel, Aashish G

    2013-12-01

    This retrospective study of 208 (204 patients) total knee arthroplasties evaluated the incidence of patellar clunk syndrome for two high-flex posterior stabilized knee prostheses; a high-flex fixed bearing prosthesis and a high-flex mobile bearing prosthesis. Patients were followed for up to two years and were evaluated for patellar clunk and component position. Knees receiving the mobile bearing had a significantly higher (p < 0.001) incidence of patellar clunk (15%) than knees receiving the fixed bearing (0%). There was a significantly higher incidence of patellar clunk in males (34.1%; p < 0.01) compared to females (8.6%). Fibrous nodules were treated surgically in 11 of the knees with patellar clunk. The design of this particular mobile bearing knee seems to contribute to patellar clunk syndrome. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Evaluation of Postoperative Range of Motion and Functional Outcomes after Cruciate-Retaining and Posterior-Stabilized High-Flexion Total Knee Arthroplasty

    PubMed Central

    Han, Chang Wook; Yang, Ick Hwan; Lee, Woo Suk; Park, Kwan Kyu

    2012-01-01

    Purpose The purpose of this study was to compare postoperative range of motion and functional outcomes among patients who received high-flexion total knee arthroplasty using cruciate-retaining (CR-Flex) and posterior-stabilized (PS-Flex) type prostheses. Materials and Methods Among 127 patients (186 knees) who underwent high-flexion total knee arthroplasty between 2005 and 2007, 92 knees were placed in the CR-Flex group, and 94 knees were placed in the PS-Flex group. After two years of postoperative follow-up, clinical and radiographic data were reviewed. Postoperative non-weight-bearing range of knee motion, angle of flexion contracture and functional outcomes based on the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) functional sub-scale were assessed and compared between the two groups. Results After the 2-year postoperative period, the mean range of motion was 131° in the CR-Flex group and 133° in the PS-Flex group. There were no significant differences in postoperative range of motion between the two groups. Only age at operation and preoperative range of motion were significantly associated with postoperative range of motion after high-flexion total knee arthroplasty. Postoperative functional outcomes based on the WOMAC functional sub-scale were slightly better in the CR-Flex group (9.2±9.1 points) than in the PS-Flex group (11.9±9.6 points); however, this difference was not statistically significant (p=non-significant). Conclusion The retention or substitution of the posterior cruciate ligament does not affect postoperative range of motion (ROM) or functional outcomes, according to 2 years of postoperative follow-up of high-flexion total knee arthroplasty. PMID:22665348

  3. Focusing on Increasing Velocity during Heavy Resistance Knee Flexion Exercise Boosts Hamstring Muscle Activity in Chronic Stroke Patients

    PubMed Central

    Jakobsen, Markus D.

    2016-01-01

    Background. Muscle strength is markedly reduced in stroke patients, which has negative implications for functional capacity and work ability. Different types of feedback during strength training exercises may alter neuromuscular activity and functional gains. Objective. To compare levels of muscle activity during conditions of blindfolding and intended high contraction speed with a normal condition of high-intensity knee flexions. Methods. Eighteen patients performed unilateral machine knee flexions with a 10-repetition maximum load. Surface electromyography (EMG) was recorded from the quadrics and hamstring muscles and normalized to maximal EMG (nEMG) of the nonparetic limb. Results. For the paretic leg, the speed condition showed higher values of muscle activity compared with the normal and blindfolded conditions for both biceps femoris and semitendinosus. Likewise, the speed condition showed higher co-contraction values compared with the normal and blindfolded conditions for the vastus lateralis. No differences were observed between exercise conditions for the nonparetic leg. Conclusion. Chronic stroke patients are capable of performing heavy resistance training with intended high speed of contraction. Focusing on speed during the concentric phase elicited higher levels of muscle activity of the hamstrings compared to normal and blindfolded conditions, which may have implications for regaining fast muscle strength in stroke survivors. PMID:27525118

  4. The functional anatomy of the iliotibial band during flexion and extension of the knee: implications for understanding iliotibial band syndrome

    PubMed Central

    Fairclough, John; Hayashi, Koji; Toumi, Hechmi; Lyons, Kathleen; Bydder, Graeme; Phillips, Nicola; Best, Thomas M; Benjamin, Mike

    2006-01-01

    Iliotibial band (ITB) syndrome is a common overuse injury in runners and cyclists. It is regarded as a friction syndrome where the ITB rubs against (and ‘rolls over’) the lateral femoral epicondyle. Here, we re-evaluate the clinical anatomy of the region to challenge the view that the ITB moves antero-posteriorly over the epicondyle. Gross anatomical and microscopical studies were conducted on the distal portion of the ITB in 15 cadavers. This was complemented by magnetic resonance (MR) imaging of six asymptomatic volunteers and studies of two athletes with acute ITB syndrome. In all cadavers, the ITB was anchored to the distal femur by fibrous strands, associated with a layer of richly innervated and vascularized fat. In no cadaver, volunteer or patient was a bursa seen. The MR scans showed that the ITB was compressed against the epicondyle at 30° of knee flexion as a consequence of tibial internal rotation, but moved laterally in extension. MR signal changes in the patients with ITB syndrome were present in the region occupied by fat, deep to the ITB. The ITB is prevented from rolling over the epicondyle by its femoral anchorage and because it is a part of the fascia lata. We suggest that it creates the illusion of movement, because of changing tension in its anterior and posterior fibres during knee flexion. Thus, on anatomical grounds, ITB overuse injuries may be more likely to be associated with fat compression beneath the tract, rather than with repetitive friction as the knee flexes and extends. PMID:16533314

  5. An individual approach for optimizing ankle-foot orthoses to improve mobility in children with spastic cerebral palsy walking with excessive knee flexion.

    PubMed

    Kerkum, Yvette L; Harlaar, Jaap; Buizer, Annemieke I; van den Noort, Josien C; Becher, Jules G; Brehm, Merel-Anne

    2016-05-01

    Ankle-Foot Orthoses (AFOs) are commonly prescribed to promote gait in children with cerebral palsy (CP). The AFO prescription process is however largely dependent on clinical experience, resulting in confusing results regarding treatment efficacy. To maximize efficacy, the AFO's mechanical properties should be tuned to the patient's underlying impairments. This study aimed to investigate whether the efficacy of a ventral shell AFO (vAFO) to reduce knee flexion and walking energy cost could be improved by individually optimizing AFO stiffness in children with CP walking with excessive knee flexion. Secondarily, the effect of the optimized vAFO on daily walking activity was investigated. Fifteen children with spastic CP were prescribed with a hinged vAFO with adjustable stiffness. Effects of a rigid, stiff, and flexible setting on knee angle and the net energy cost (EC) [Jkg(-1)m(-1)] were assessed to individually select the optimal stiffness. After three months, net EC, daily walking activity [stridesmin(-1)] and knee angle [deg] while walking with the optimized vAFO were compared to walking with shoes-only. A near significant 9% (p=0.077) decrease in net EC (-0.5Jkg(-1)m(-1)) was found for walking with the optimized vAFO compared to shoes-only. Daily activity remained unchanged. Knee flexion in stance was reduced by 2.4° (p=0.006). These results show that children with CP who walk with excessive knee flexion show a small, but significant reduction of knee flexion in stance as a result of wearing individually optimized vAFOs. Data suggest that this also improves gait efficiency for which an individual approach to AFO prescription is emphasized.

  6. Ranges of Cervical Intervertebral Disc Deformation during an In-Vivo Dynamic Flexion-Extension of the Neck.

    PubMed

    Yu, Yan; Mao, Haiqing; Li, Jing-Sheng; Tsai, Tsung-Yuan; Cheng, Liming; Wood, Kirkham B; Li, Guoan; Cha, Thomas D

    2017-03-23

    While abnormal loading is widely believed to cause cervical spine disc diseases, in-vivo cervical disc deformation during dynamic neck motion has not been well delineated. This study investigated the range of cervical disc deformation during an in-vivo functional flexion-extension of the neck. Ten asymptomatic human subjects were tested using a combined dual fluoroscopic imaging system and MRI based 3D modeling technique. Overall disc deformation was determined using the changes of the space geometry between upper and lower endplates of each intervertebral segment (C3/4, C4/5, C5/6 and C6/7). Five points (anterior, center, posterior, left and right) of each disc were analyzed to examine the disc deformation distributions. The data indicated that between the functional maximum flexion and extension of the neck, the anterior points of the discs experienced large changes of distraction/compression deformation and shear deformation. The higher level discs experienced higher ranges of disc deformation. No significant difference was found in deformation ranges at posterior points of all discs. The data indicated that the range of disc deformation is disc level dependent and the anterior region experienced larger changes of deformation than the center and posterior regions, except for the C6/7 disc. The data obtained from this study could serve as baseline knowledge for the understanding of the cervical spine disc biomechanics and for investigation of the biomechanical etiology of disc diseases. These data could also provide insights for development of motion preservation surgeries for cervical spine.

  7. Fixation of high-flexion total knee prostheses: five-year follow-up results of a four-arm randomized controlled clinical and roentgen stereophotogrammetric analysis study.

    PubMed

    Nieuwenhuijse, Marc J; van der Voort, Paul; Kaptein, Bart L; van der Linden-van der Zwaag, H M J; Valstar, Edward R; Nelissen, Rob G H H

    2013-10-02

    High-flexion total knee arthroplasty was introduced to meet the demands of daily activity requiring increased knee flexion. However, concerns have been raised regarding the fixation of high-flexion total knee arthroplasty components and increased rates of loosening have been reported. To date, migration, and thus fixation, of high-flexion total knee arthroplasty components has not been analyzed and the preferential bearing type (mobile or fixed) is unknown. Of eighty-six consecutive eligible patients, seventy-four patients (seventy-eight knees) scheduled for total knee arthroplasty were randomized to one of four Legacy Posterior Stabilized (LPS) total knee prosthesis designs: (1) LPS-Flex mobile, (2) LPS-Flex fixed, (3) LPS mobile, and (4) LPS fixed. The primary outcome was component migration measured with use of Roentgen stereophotogrammetric analysis, and secondary outcomes were postoperative knee flexion and extension and Knee Society Score. Patients were evaluated postoperatively at six, twelve, twenty-six, and fifty-two weeks and annually thereafter. At the five-year follow-up, eight patients had died and two patients were lost to follow-up. Seventy-seven tibial and forty-two femoral components were suitable for migration measurements. The overall five-year migration of the seventy-seven tibial components was not significantly different among the four total knee prosthesis designs (compared with the LPS fixed design, the range of overall mean differences for the other three designs was 0.02 to 0.25 mm) and migration was comparable at the two and five-year follow-up. Migration stabilized in all but three components (two LPS-Flex mobile and one LPS fixed); one of these components has already been revised and was aseptically loose. The overall five-year migration of the forty-two femoral components was comparable among the four designs (compared with the LPS fixed design, the range of overall mean differences for the other three designs was 0.01 to 0.18 mm) and

  8. Study of the influence of degenerative intervertebral disc changes on the deformation behavior of the cervical spine segment in flexion

    NASA Astrophysics Data System (ADS)

    Kolmakova, Tatyana V.

    2016-11-01

    The paper describes the model of the cervical spine segment (C3-C4) and the calculation results of the deformation behavior of the segment under degenerative changes of the intervertebral disc. The segment model was built based on the experimental literature data taking into account the presence of the cortical and cancellous bone tissue of vertebral bodies. The calculation results show that degenerative changes of the intervertebral disc cause the immobility of the C3 vertebra at flexion.

  9. Reliability of knee extension and flexion measurements using the Con-Trex isokinetic dynamometer.

    PubMed

    Maffiuletti, Nicola A; Bizzini, Mario; Desbrosses, Kevin; Babault, Nicolas; Munzinger, Urs

    2007-11-01

    The aim of this study was to evaluate the reliability of isokinetic and isometric assessments of the knee extensor and the flexor muscle function using the Con-Trex isokinetic dynamometer. Thirty healthy subjects (15 males, 15 females) were tested and retested 7 days later for maximal strength (isokinetic peak torque, work, power and angle of peak torque as well as isometric maximal voluntary contraction torque and rate of torque development) and fatigue (per cent loss and linear slope of torque and work across a series of 20 contractions). For both the knee extensor and the flexor muscle groups, all strength data - except angle of peak torque - demonstrated moderate-to-high reliability, with intraclass correlation coefficients (ICC) higher than 0.86. The highest reliability was observed for concentric peak torque of the knee extensor muscles (ICC = 0.99). Test-retest reliability of fatigue variables was moderate for the knee extensor (ICC range 0.84-0.89) and insufficient-to-moderate for the knee flexor muscles (ICC range 0.78-0.81). The more reliable index of muscle fatigue was the linear slope of the decline in work output. These findings establish the reliability of isokinetic and isometric measurements using the Con-Trex machine.

  10. Restoring the anatomical tibial slope and limb axis may maximise post-operative flexion in posterior-stabilised total knee replacements.

    PubMed

    Singh, G; Tan, J H; Sng, B Y; Awiszus, F; Lohmann, C H; Nathan, S S

    2013-10-01

    The optimal management of the tibial slope in achieving a high flexion angle in posterior-stabilised (PS) total knee replacement (TKR) is not well understood, and most studies evaluating the posterior tibial slope have been conducted on cruciate-retaining TKRs. We analysed pre- and post-operative tibial slope differences, pre- and post-operative coronal knee alignment and post-operative maximum flexion angle in 167 patients undergoing 209 TKRs. The mean pre-operative posterior tibial slope was 8.6° (1.3° to 17°) and post-operatively it was 8.0° (0.1° to 16.7°). Multiple linear regression analysis showed that the absolute difference between pre- and post-operative tibial slope (p < 0.001), post-operative coronal alignment (p = 0.02) and pre-operative range of movement (p < 0.001) predicted post-operative flexion. The variance of change in tibial slope became larger as the post-operative maximum flexion angle decreased. The odds ratio of having a post-operative flexion angle < 100° was 17.6 if the slope change was > 2°. Our data suggest that recreation of the anatomical tibial slope appears to improve maximum flexion after posterior-stabilised TKR, provided coronal alignment has been restored.

  11. Baseline knee adduction and flexion moments during walking are both associated with five year cartilage changes in patients with medial knee osteoarthritis

    PubMed Central

    Chehab, Eric F.; Favre, Julien; Erhart-Hledik, Jennifer C.; Andriacchi, Thomas P.

    2014-01-01

    Objective To test the hypothesis that knee cartilage changes over five years are associated with baseline peak knee adduction moment (KAM) and peak knee flexion moment (KFM) during early stance. Design Baseline KAM and KFM were measured in sixteen subjects with medial knee OA. Regional changes in cartilage thickness and changes in medial-to-lateral thickness ratio were quantified using magnetic resonance imaging at baseline and again after five years. Multiple regression was used to determine whether baseline measures of KAM and KFM were associated with cartilage changes over five years. Associations with baseline pain score, Kellgren-Lawrence grade, walking speed, age, gender, and body mass index were tested one-by-one in the presence of KAM and KFM. Results Changes over five years in femoral medial-to-lateral thickness ratio were associated with baseline KAM, KFM, and pain score (R2=0.60, p=0.010), and most significantly with KAM (R2=0.33, p=0.019). Changes in tibial medial-to-lateral thickness ratio were associated with baseline KAM, KFM, and walking speed (R2=0.49, p=0.039), with KFM driving this association (R2=0.40, p=0.009). Changes in medial tibial thickness were associated with baseline KAM, KFM, and walking speed (R2=0.49, p=0.041); KFM also drove this association (R2=0.42, p=0.006). Conclusions The findings that the KAM has a greater influence on femoral cartilage change and the KFM has a greater influence on tibial cartilage change provide new insight into the tibiofemoral variations in cartilage changes associated with walking kinetics. These results suggest that both KAM and KFM should be considered when designing disease interventions as well as when assessing the risk for OA progression. PMID:25211281

  12. Relationship between electromyographic activity of the vastus lateralis while standing and the extent of bilateral simulated knee-flexion contractures.

    PubMed

    Potter, P J; Kirby, R L

    1991-12-01

    The effect of simulated bilateral knee-flexion contractures (KFC) on the electromyographic (EMG) activity of the vastus lateralis was studied by testing 10 normal subjects using surface EMG to test the hypothesis that the activity of the knee extensors would increase as a function of the severity of the contracture. The root mean square of the EMG activity was determined from four 4-s samples taken at 30-s intervals, during 2 min of standing in each of five positions of simulated KFC (0 degree, 10 degrees, 20 degrees, 30 degrees and 40 degrees). A randomly balanced order of conditions was used. KFC were simulated in each subject by means of an adjustable line from the subject's waist to the sole of each foot. An analysis of variance was used to contrast EMG activity, and a significant difference was found between each of the positions (P less than 0.05). The mean (+/- 1 SD) EMG activity, expressed as a percentage of the maximum voluntary contraction, was 0.3% (+/- 0.2) at 0 degree, 7.6% (+/- 5.6) at 10 degrees, 10.9% (+/- 7.6) at 20 degrees, 16.6% (+/- 12.4) at 30 degrees and 24.0% (+/- 14.0) at 40 degrees. A linear relationship was found (r2 = 0.986), expressed by the equation y = 0.62 + 0.56 x, where y represents EMG activity and x represents the extent of simulated KFC (P = 0.0007). The results provide insight into the increased knee extensor activity necessary to stand with KFC and underline the importance of treating this common disorder.

  13. Total Knee Arthroplasty in Severe Valgus Osteoarthritis Excellent Early Results in a 90-Year-Old Patient with a Valgus Deformity of 47°

    PubMed Central

    Kernen, Rolf; Mueller, Sebastian Andreas

    2017-01-01

    Grade III valgus deformity (tibiofemoral alignment > 20°) is present in only 0.5% of patients receiving total knee arthroplasty. Furthermore, cases with a valgus deformity exceeding 40° are even rarer. Since they mostly affect elderly, polymorbid patients, successful outcome means a great challenge. We report on a case of a 90-year-old patient with a valgus deformity of 47°. The patient was preoperatively restricted to a wheel chair, unable to walk, and only able to stand for a few seconds. The maximal knee flexion was 100°, and there was an extension deficit of 15°. The WOMAC score was 91; the EQ-5D-5L Index was 0.048. She was treated with a constrained hinged prosthesis. Postoperatively, the axis was 6° valgus. After 3 months of rehabilitation, she was independent using a wheeled walker. The maximal flexion of the knee was 110° and there was no extension deficit. The WOMAC score was 45; the EQ-5D-5L Index was 0.813. This case demonstrates the possibility of a satisfactory result and an improvement in quality of life and mobility with a plausible timetable and with reasonable use of resources even in advanced age and severe valgus deformity. PMID:28386499

  14. Effects of upright weight bearing and the knee flexion angle on patellofemoral indices using magnetic resonance imaging in patients with patellofemoral instability.

    PubMed

    Becher, Christoph; Fleischer, Benjamin; Rase, Marten; Schumacher, Thees; Ettinger, Max; Ostermeier, Sven; Smith, Tomas

    2017-08-01

    This study analysed the effects of upright weight bearing and the knee flexion angle on patellofemoral indices, determined using magnetic resonance imaging (MRI), in patients with patellofemoral instability (PI). Healthy volunteers (control group, n = 9) and PI patients (PI group, n = 16) were scanned in an open-configuration MRI scanner during upright weight bearing and supine non-weight bearing positions at full extension (0° flexion) and at 15°, 30°, and 45° flexion. Patellofemoral indices included the Insall-Salvati Index, Caton-Deschamp Index, and Patellotrochlear Index (PTI) to determine patellar height and the patellar tilt angle (PTA), bisect offset (BO), and the tibial tubercle-trochlear groove (TT-TG) distance to assess patellar rotation and translation with respect to the femur and alignment of the extensor mechanism. A significant interaction effect of weight bearing by flexion angle was observed for the PTI, PTA, and BO for subjects with PI. At full extension, post hoc pairwise comparisons revealed a significant effect of weight bearing on the indices, with increased patellar height and increased PTA and BO in the PI group. Except for the BO, no such changes were seen in the control group. Independent of weight bearing, flexing the knee caused the PTA, BO, and TT-TG distance to be significantly reduced. Upright weight bearing and the knee flexion angle affected patellofemoral MRI indices in PI patients, with significantly increased values at full extension. The observations of this study provide a caution to be considered by professionals when treating PI patients. These patients should be evaluated clinically and radiographically at full extension and various flexion angles in context with quadriceps engagement. Explorative case-control study, Level III.

  15. Measurement of the end-to-end distances between the femoral and tibial insertion sites of the anterior cruciate ligament during knee flexion and with rotational torque.

    PubMed

    Wang, Joon Ho; Kato, Yuki; Ingham, Sheila J M; Maeyama, Akira; Linde-Rosen, Monica; Smolinski, Patrick; Fu, Freddie H

    2012-10-01

    The aim of this study was to determine the end-to-end distance changes in anterior cruciate ligament (ACL) fibers during flexion/extension and internal/external rotation of the knee. The positional relation between the femur and tibia of 10 knees was digitized on a robotic system during flexion/extension and with an internal/external rotational torque (5 Nm). The ACL insertion site data, acquired by 3-dimensional scanning, were superimposed on the positional data. The end-to-end distances of 5 representative points on the femoral and tibial insertion sites of the ACL were calculated. The end-to-end distances of all representative points except the most anterior points were longest at full extension and shortest at 90°. The distances of the anteromedial (AM) and posterolateral (PL) bundles were 37.2 ± 2.1 mm and 27.5 ± 2.8 mm, respectively, at full extension and 34.7 ± 2.4 mm and 20.7 ± 2.3 mm, respectively, at 90°. Only 4 knees had an isometric point, which was 1 of the 3 anterior points. Under an internal torque, both bundles became longer with statistical meaning at all flexion angles (P = .005). The end-to-end distances of all points became longest with internal torque at full extension and shortest with an external torque at 90°. Only 4 of 10 specimens had an isometric point at a variable anterior point. The end-to-end distances of the AM and PL bundles were longer in extension and shorter in flexion. The nonisometric tendency of the ACL and the end-to-end distance change during knee flexion/extension and internal/external rotation should be considered during ACL reconstruction to avoid overconstraint of the graft. Copyright © 2012 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  16. Severe valgus deformity of the knee with permanent patellar dislocation associated with melorheostosis: a case report and review of the literature.

    PubMed

    Kitta, Yuki; Niki, Yasuo; Udagawa, Kazuhiko; Enomoto, Hiroyuki; Toyama, Yoshiaki; Suda, Yasunori

    2014-03-01

    We present a case of an 8-year-old boy diagnosed with melorheostosis who was suffering from severe genu valgum, permanent dislocation of the patella, knee flexion contracture and leg length shortening. Soft tissue contracture of the limb and subsequent joint deformities were reported to represent clinical manifestations of pediatric melorheostosis. As the epiphyseal plate had not closed, patellar reduction was achieved by soft tissue surgical stabilization, including lateral retinacular release, medial retinaculum plication, and transfer of the lateral half of the patellar tendon. At 4 years postoperatively, as a result of improved limb alignment and knee flexion contracture, the leg length shortening has improved, and the patient does not limp and participates in sports activities. Surgical intervention should be performed as early as possible, because genu valgum and external rotation of the tibia may deteriorate with age, rendering the patellar dislocation irreversible in patients with melorheostosis before epiphyseal closure. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Kinematically aligned total knee arthroplasty limits high tibial forces, differences in tibial forces between compartments, and abnormal tibial contact kinematics during passive flexion.

    PubMed

    Roth, Joshua D; Howell, Stephen M; Hull, Maury L

    2017-09-07

    Following total knee arthroplasty (TKA), high tibial forces, large differences in tibial forces between the medial and lateral compartments, and anterior translation of the contact locations of the femoral component on the tibial component during passive flexion indicate abnormal knee function. Because the goal of kinematically aligned TKA is to restore native knee function without soft tissue release, the objectives were to determine how well kinematically aligned TKA limits high tibial forces, differences in tibial forces between compartments, and anterior translation of the contact locations of the femoral component on the tibial component during passive flexion. Using cruciate retaining components, kinematically aligned TKA was performed on thirteen human cadaveric knee specimens with use of manual instruments without soft tissue release. The tibial forces and tibial contact locations were measured in both the medial and lateral compartments from 0° to 120° of passive flexion using a custom tibial force sensor. The average total tibial force (i.e. sum of medial + lateral) ranged from 5 to 116 N. The only significant average differences in tibial force between compartments occurred at 0° of flexion (29 N, p = 0.0008). The contact locations in both compartments translated posteriorly in all thirteen kinematically aligned TKAs by an average of 14 mm (p < 0.0001) and 18 mm (p < 0.0001) in the medial and lateral compartments, respectively, from 0° to 120° of flexion. After kinematically aligned TKA, average total tibial forces due to the soft tissue restraints were limited to 116 N, average differences in tibial forces between compartments were limited to 29 N, and a net posterior translation of the tibial contact locations was observed in all kinematically aligned TKAs during passive flexion from 0° to 120°, which are similar to what has been measured previously in native knees. While confirmation in vivo is warranted, these findings give

  18. Effect of knee flexion angle on ground reaction forces, knee moments and muscle co-contraction during an impact-like deceleration landing: implications for the non-contact mechanism of ACL injury.

    PubMed

    Podraza, Jeffery T; White, Scott C

    2010-08-01

    Investigating landing kinetics and neuromuscular control strategies during rapid deceleration movements is a prerequisite to understanding the non-contact mechanism of ACL injury. The purpose of this study was to quantify the effect of knee flexion angle on ground reaction forces, net knee joint moments, muscle co-contraction and lower extremity muscles during an impact-like, deceleration task. Ground reaction forces and knee joint moments were determined from video and force plate records of 10 healthy male subjects performing rapid deceleration single leg landings from a 10.5 cm height with different degrees of knee flexion at landing. Muscle co-contraction was based on muscle moments calculated from an EMG-to-moment processing model. Ground reaction forces and co-contraction indices decreased while knee extensor moments increased significantly with increased degrees of knee flexion at landing (all p<0.005). Higher ground reaction forces when landing in an extended knee position suggests they are a contributing factor in non-contact ACL injuries. Increased knee extensor moments and less co-contraction with flexed knee landings suggest that quadriceps overload may not be the primary cause of non-contact ACL injuries. The results bring into question the counterbalancing role of the hamstrings during dynamic movements. The soleus may be a valuable synergist stabilizing the tibia against anterior translation at landing. Movement strategies that lessen the propagation of reaction forces up the kinetic chain may help prevent non-contact ACL injuries. The relative interaction of all involved thigh and lower leg muscles, not just the quadriceps and hamstrings should be considered when interpreting non-contact ACL injury mechanisms. Copyright 2010 Elsevier B.V. All rights reserved.

  19. Total Knee Arthroplasty in Patients with Blount Disease or Blount-Like Deformity.

    PubMed

    Natoli, Roman M; Nypaver, Chrissy M; Schiff, Adam P; Hopkinson, William J; Rees, Harold W

    2016-01-01

    Blount disease is associated with complex deformity of the proximal tibia, and some patients will develop knee osteoarthritis. Five patients (eight knees) with Blount disease or Blount-like deformity underwent total knee arthroplasty. Mean proximal tibial metaphyseal-diaphyseal angle was 20.75°. Each patient had substantial posteromedial tibial bony defects and six knees required extensive medial releases. Two knees required increased constraint at index procedure. One patient has undergone bilateral revision surgery with rotating hinge prostheses. Mean WOMAC scores were 13.5 and Knee Society scores were 212.5 at average 75.2 month follow-up. Despite technical challenges, patients with these deformities can have successful outcomes after total knee arthroplasty. Surgeons should be prepared to address posteromedial tibial bony defects and consider constrained arthroplasty at the index procedure.

  20. Radiographic Measurement of Joint Space Width Using the Fixed Flexion View in 1,102 Knees of Japanese Patients with Osteoarthritis in Comparison with the Standing Extended View

    PubMed Central

    Kan, Hiroyuki; Arai, Yuji; Kobayashi, Masashi; Nakagawa, Shuji; Inoue, Hiroaki; Hino, Manabu; Komaki, Shintaro; Ikoma, Kazuya; Ueshima, Keiichiro; Fujiwara, Hiroyoshi; Kubo, Toshikazu

    2017-01-01

    Purpose The fixed flexion view (FFV) of the knee is considered useful for evaluating the joint space when assessing the severity of osteoarthritis (OA) of the knee. To clarify the usefulness of FFV for evaluation of the joint space and severity of knee OA, this study evaluated changes in the joint space on the FFV and standing extended view (SEV) in patients with knee OA. Materials and Methods The SEV and FFV images were acquired in 567 patients (1,102 knees) who visited the hospital with a chief complaint of knee joint pain. Medial joint space width (MJSW) and Kellgren-Lawrence (K-L) classification assessed using the SEV and FFV images were compared. Results Mean MJSW was significantly smaller when assessed on the FFV than on the SEV (3.02±1.55 mm vs. 4.31±1.30 mm; p<0.001). The K-L grade was the same or higher on the FFV than on the SEV. Conclusions The FFV is more useful than the SEV for evaluating the joint space in OA knees. Treatment strategies in patients with knee OA should be determined based on routinely acquired FFV images. PMID:28231651

  1. Side effects and potential risk factors of botulinum toxin type A intramuscular injections in knee flexion contractures of hemophiliacs.

    PubMed

    Rodriguez-Merchan, E Carlos; De la Corte-Rodriguez, Hortensia

    2017-07-01

    Knee flexion contracture (KFC) is a common complication of recurrent hemarthrosis in children and young adults with hemophilia. If the KFC is not prevented (by means of primary prophylaxis) and treated properly and early (be means of physical medicine and rehabilitation), it will become fixed. Areas covered: The aim of this article is to review the potential role of botulinum toxin type A (BTX-A) intramuscular injections for the treatment of KFC in people with hemophilia (PWH). Expert commentary: Although two recent reports have mentioned the benefits of intramuscular injections of BTX-A in PWH with KFC, the data are still scant and too preliminary. The use of intramuscular injections of BTX-A in PWH today should not be recommended until more case studies/small series (ideally well-designed clinical trials) fully demonstrate that this is safe and effective. The risks of intramuscular injections to a hemophilia patient cannot be underestimated (iatrogenic muscle hematomas and pseudotumors). This paper calls the attention of hemophilia treaters on the potential risks of this apparently interesting technique. The current use of BTX-A intramuscular injections in KFC of PWH could make no sense. Raising false expectations in these patients should be avoided.

  2. The Effects of Varying Ankle Foot Orthosis Stiffness on Gait in Children with Spastic Cerebral Palsy Who Walk with Excessive Knee Flexion

    PubMed Central

    Kerkum, Yvette L.; Buizer, Annemieke I.; van den Noort, Josien C.; Becher, Jules G.; Harlaar, Jaap; Brehm, Merel-Anne

    2015-01-01

    Introduction Rigid Ankle-Foot Orthoses (AFOs) are commonly prescribed to counteract excessive knee flexion during the stance phase of gait in children with cerebral palsy (CP). While rigid AFOs may normalize knee kinematics and kinetics effectively, it has the disadvantage of impeding push-off power. A spring-like AFO may enhance push-off power, which may come at the cost of reducing the knee flexion less effectively. Optimizing this trade-off between enhancing push-off power and normalizing knee flexion in stance is expected to maximize gait efficiency. This study investigated the effects of varying AFO stiffness on gait biomechanics and efficiency in children with CP who walk with excessive knee flexion in stance. Fifteen children with spastic CP (11 boys, 10±2 years) were prescribed with a ventral shell spring-hinged AFO (vAFO). The hinge was set into a rigid, or spring-like setting, using both a stiff and flexible performance. At baseline (i.e. shoes-only) and for each vAFO, a 3D-gait analysis and 6-minute walk test with breath-gas analysis were performed at comfortable speed. Lower limb joint kinematics and kinetics were calculated. From the 6-minute walk test, walking speed and the net energy cost were determined. A generalized estimation equation (p<0.05) was used to analyze the effects of different conditions. Compared to shoes-only, all vAFOs improved the knee angle and net moment similarly. Ankle power generation and work were preserved only by the spring-like vAFOs. All vAFOs decreased the net energy cost compared to shoes-only, but no differences were found between vAFOs, showing that the effects of spring-like vAFOs to promote push-off power did not lead to greater reductions in walking energy cost. These findings suggest that, in this specific group of children with spastic CP, the vAFO stiffness that maximizes gait efficiency is primarily determined by its effect on knee kinematics and kinetics rather than by its effect on push-off power. Trial

  3. Surgical correction of angular deformity of the knee in children with renal osteodystrophy.

    PubMed

    Oppenheim, W L; Fischer, S R; Salusky, I B

    1997-01-01

    Twenty-nine children with renal osteodystrophy (RO) and angular deformities about the knee were studied, including 19 in whom 36 corrective operations were performed. Corrective osteotomy of the distal femur was performed in 20 knees, osteotomy of the proximal tibia in 11 knees, combined femoral/tibial osteotomy in three knees, and medial physeal stapling in two knees. The indication for surgery was a deformity significant enough to interfere with gait. Complications occurred in three patients and recurrence severe enough to require repeated surgery occurred in four patients. Patients who required repeated osteotomy appeared to have had poor metabolic control during the initial surgery, as measured by an increased alkaline phosphatase. Surgery for children with RO and knee deformities is quite feasible but requires careful surgical planning and preoperative metabolic stabilization. Whether to correct the femur or tibia can be determined by evaluating full-length films of the lower extremities.

  4. Measurement of knee joint gaps without bone resection: "physiologic" extension and flexion gaps in total knee arthroplasty are asymmetric and unequal and anterior and posterior cruciate ligament resections produce different gap changes.

    PubMed

    Nowakowski, Andrej Maria; Majewski, Martin; Müller-Gerbl, Magdalena; Valderrabano, Victor

    2012-04-01

    General agreement is that flexion and extension gaps should be equal and symmetrical in total knee arthroplasty (TKA) procedures. However, comparisons using a standard TKA approach to normal knee joints that have not undergone bone resection are currently unavailable. Since bony preparation can influence capsule and ligament tension, our purpose was to perform measurements without this influence. Ten normal cadaveric knees were assessed using a standard medial parapatellar TKA approach with patellar subluxation. Gap measurements were carried out twice each alternating 100 and 200 N per compartment using a prototypical force-determining ligament balancer without the need for bony resection. Initial measurements were performed in extension, followed by 908 of flexion. The ACL was then resected, and finally the PCL was resected, and measurements were carried out in an analogous fashion. In general, the lateral compartment could be stretched further than the medial compartment, and the corresponding flexion gap values were significantly larger. ACL resection predominantly increased extension gaps, while PCL resection increased flexion gaps. Distraction force of 100 N per compartment appeared adequate; increasing to 200 N did not improve the results.

  5. Comparison of reaction forces on the anterior cruciate and anterolateral ligaments during internal rotation and anterior drawer forces at different flexion angles of the knee joint.

    PubMed

    Uğur, Levent

    2017-03-02

    Having a complicated anatomy, the knee joint has been further detailed and a new formation defined, the anterolateral ligament (ALL), in recent studies. While the importance of this ligament, which previously was associated with Segond fractures, was explained via clinical, radiologic and biomechanical studies, and basically, is thought to be a fixator structures for the tibia against internal rotation stress. Although in recent studies efficient surgical treatment was applied to patients who underwent anterior cruciate ligament (ACL) operation, some patients having a positive pivot test highlights the clinical importance of the ALL. The aim of this study is to evaluate reaction forces of different flexion angles on the tibia during internal rotation and anterior drawer tests on both the ALL and ACL, and to examine theimportance of this ligament in knee biomechanics by a finite element analysis method. In this study, normal anatomy knee joint was modelled using Computed Tomography images from lower extremity length in DICOM format. 0°, 15°,30°,45°,60°,75° and 90° angles of flexion were applied, respectively, to these models and reaction force vectors formed on both ligaments were examined separately and as total vector and size by applying internal rotation and anterior drawer forces on each model. Non-linear analysis was conducted using ANSYS (version 17) with the same limit conditions applied to all models. After all models were examined, in general when comparing reaction forces, those on the ACL were found to be higher. However, when vectoral directions were examined, forces on ALL increased with increased flexion ratio and internal rotation momentum. Beyond 30° flexion, the tensile force on the ALL is increased and compressive overload on the ACL occurs. The ALL plays an important role in stability, especially against internal rotation forces, and an increased knee joint flexion ratio increases the stability contribution ratio. In particular, at 30

  6. Higher Knee Flexion Moment During the Second Half of the Stance Phase of Gait Is Associated With the Progression of Osteoarthritis of the Patellofemoral Joint on Magnetic Resonance Imaging

    PubMed Central

    Teng, Hsiang-Ling; Macleod, Toran D.; Link, Thomas M.; Majumdar, Sharmila; Souza, Richard B.

    2016-01-01

    STUDY DESIGN Controlled laboratory study, longitudinal design. OBJECTIVE To examine whether baseline knee flexion moment or impulse during walking is associated with the progression of osteoarthritis (OA) with magnetic resonance imaging of the patellofemoral joint (PFJ) at 1 year. BACKGROUND Patellofemoral joint OA is highly prevalent and a major source of pain and dysfunction. The biomechanical factors associated with the progression of PFJ OA remain unclear. METHODS Three-dimensional gait analyses were performed at baseline. Magnetic resonance imaging of the knee (high-resolution, 3-D, fast spin-echo sequence) was used to identify PFJ cartilage and bone marrow edema–like lesions at baseline and a 1-year follow-up. The severity of PFJ OA progression was defined using the modified Whole-Organ Magnetic Resonance Imaging Score when new or increased cartilage or bone marrow edema–like lesions were observed at 1 year. Peak external knee flexion moment and flexion moment impulse during the first and second halves of the stance phase of gait were compared between progressors and nonprogressors, and used to predict progression after adjusting for age, sex, body mass index, and presence of baseline PFJ OA. RESULTS Sixty-one participants with no knee OA or isolated PFJ OA were included. Patellofemoral joint OA progressors (n = 10) demonstrated significantly higher peak knee flexion moment (P = .01) and flexion moment impulse (P = .04) during the second half of stance at baseline compared to nonprogressors. Logistic regression showed that higher peak knee flexion moment during the second half of the stance phase was significantly associated with progression at 1 year (adjusted odds ratio = 3.3, P = .01). CONCLUSION Peak knee flexion moment and flexion moment impulse during the second half of stance are related to the progression of PFJ OA and may need to be considered when treating individuals who are at risk of or who have PFJ OA. PMID:26161626

  7. Navigation-based tibial rotation at 90° of flexion is associated with better range of motion in navigated total knee arthroplasty.

    PubMed

    Ishida, Kazunari; Shibanuma, Nao; Matsumoto, Tomoyuki; Sasaki, Hiroshi; Takayama, Koji; Hiroshima, Yuji; Kuroda, Ryosuke; Kurosaka, Masahiro

    2016-08-01

    In clinical practice, people with better femorotibial rotation in the flexed position often achieve a favourable postoperative maximum flexion angle (MFA). However, no objective data have been reported to support this clinical observation. In the present study, we aimed to investigate the correlation between the amount of intraoperative rotation and the pre- and postoperative flexion angles. Fifty-five patients with varus osteoarthritis undergoing computer-assisted posterior-stabilized total knee arthroplasty (TKA) were enrolled. After registration, rotational stress was applied towards the knee joint, and the rotational angles were recorded by using a navigation system at maximum extension and 90° of flexion. After implantation, rotational stress was applied for a second time, and the angles were recorded once more. The MFA was measured before surgery and 1 month after surgery, and the correlation between the amount of femorotibial rotation during surgery and the MFA was statistically evaluated. Although the amount of tibial rotation at maximum extension was not correlated with the MFA, the amount of tibial rotation at 90° of flexion after registration was positively correlated with the pre- and postoperative MFA (both p < 0.005). However, no significant relationship was observed between the amount of tibial rotation after implantation and the postoperative MFA (n.s.). The results showed that better femorotibial rotation at 90° of flexion is associated with a favourable postoperative MFA, suggesting that the flexibility of the surrounding soft tissues is an important factor for obtaining a better MFA, which has important clinical relevance. Hence, further evaluation of navigation-based kinematics during TKA may provide useful information on MFA. Diagnostic studies, development of diagnostic criteria in a consecutive series of patients, and a universally applied "gold" standard, Level II.

  8. Computer-assisted surgery patterns of ligamentous deformity of the knee: a clinical and cadaveric study.

    PubMed

    Schwarzkopf, Ran; Hadley, Scott; Abbasi, Mohammed; Meere, Patrick A

    2013-08-01

    Knee malalignment during total knee arthroplasty (TKA) is commonly classified as either varus or valgus on the basis of a standing anteroposterior radiograph. Computer-assisted surgery (CAS) navigation TKA provides precise dynamic evaluation of knee alignment throughout the full range of motion (FROM). The goal of this study was to classify patterns of CAS-generated knee deformity curves that match specific soft tissue contracture combinations. This can then be applied as an algorithm for soft tissue balancing on the basis of the preoperative knee deformity curve. Computer navigation-generated graphs from 65 consecutive TKA procedures performed by a single surgeon were analyzed. A stress-strain curve of the coronal alignment of the knee was recorded throughout FROM before bony resection. All graphs were classified into groups according to their pattern. Cadaveric knee models were then used to test the correlation between isolated and combined ligamentous contractures and identified CAS deformity curves. An analysis of the intraoperative knee alignment graphs revealed four distinct patterns of coronal deformity on the basis of intraoperative data: 13% diagonal, 18.5% C-shaped, 43.5% comma shaped, and 25% S-shaped. Each represents the change in varus and valgus alignment during FROM. All patterns were reproduced with cadaveric knees by recreating specific contracture constellations. A tight posterior capsule gave an S-shaped curve, a tight lateral collateral ligament gave a C-shaped curve, tight medial collateral ligament gave a diagonal curve, and a tight posterior lateral corner gave a comma-shaped curve. Release of the specific contractures resulted in correction of all patterns of deformity as measured by CAS. We propose a new classification system for coronal plane knee deformity throughout FROM. This system intends to match individual and combined soft tissue pathological contractures to specific stress-strain curves obtained through routine knee CAS

  9. Knee extension and flexion strength asymmetry in Human Immunodeficiency Virus positive subjects: a cross-sectional study.

    PubMed

    Oliveira, Vitor H F; Wiechmann, Susana L; Narciso, Argéria M S; Deminice, Rafael

    2017-07-03

    Human Immunodeficiency Virus positive subjects present impairment in muscle function, neural activation, balance, and gait. In other populations, all of these factors have been associated with muscle strength asymmetry. To investigate the existence of muscle strength asymmetry between dominant and non-dominant lower limbs and to determine the hamstrings-to-quadriceps strength ratio in Human Immunodeficiency Virus positive subjects. In this cross-sectional study, 48 subjects were included (22 men and 26 women; mean age 44.6 years), all of them under highly active antiretroviral therapy. They performed isokinetic strength efforts at speeds of 60°/s and 180°/s for knee extension and flexion in concentric-concentric mode. Peak torque was higher (p<0.01) at 60°/s for quadriceps (193, SD=57 vs. 173, SD=55% body mass) and hamstrings (97, SD=36 vs. 90, SD=37% body mass) in dominant compared to non-dominant. Similarly, peak torque was higher at 180°/s (quadriceps 128, SD=44 vs. 112, SD=42; hamstrings 64, SD=24 vs. 57, SD=26% body mass) in dominant. Average power was also higher for all muscle groups and speeds, comparing dominant with non-dominant. The hamstrings-to-quadriceps ratio at 60°/s was 0.50 for dominant and 0.52 for non-dominant, and at 180°/s, it was 0.51 for both limbs, with no significant difference between them. The percentage of subjects with strength asymmetry ranged from 46 to 58%, depending upon muscle group and speed analyzed. Human Immunodeficiency Virus positive subjects present muscle strength asymmetry between lower limbs, assessed through isokinetic dynamometry. Copyright © 2017 Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia. Publicado por Elsevier Editora Ltda. All rights reserved.

  10. [Relationship between angular deformity and primary osteoarthritis of the knee. Review article].

    PubMed

    Álvarez-López, C A; García-Lorenzo, Y C

    2015-01-01

    Osteoarthritis of the knee is a common disease and angular deformities are usually associated to this degenerative affection. Secondary causes of angular deformities are well known in the scientific literature, but there are not many articles about the relationship between angular deformities and primary osteoarthritis. To deepen in the relationship between angular deformities and primary osteoarthritis of the knee. We conducted a literature review of a total of 300 articles in PubMed, Medline and Hinari locator information by EndNote, 52 of them were used and selected quotes to do the review, 47 of them in the last five years, including five books. A revision of important biochemical and biomechanics aspects were made in regards to the relationship between angular deformities and primary osteoarthritis of the knee. Causes of deformities according to the sagittal, coronal and rotational axis were taken into account. Factors related to deformities could be osseous or soft tissues of the knee joint. Deformities of the knee in patients suffering from primary osteoarthritis are common and there are osseous and soft tissues causes to justified the presence of these deformities.

  11. Computer-assisted total knee arthroplasty for arthritis with extra-articular deformity.

    PubMed

    Mullaji, Arun; Shetty, Gautam M

    2009-12-01

    Forty extra-articular deformities (22 femoral and 18 tibial) in 34 patients (mean age, 63.1 years) were studied. Mean coronal extra-articular deformity was 9.3 degrees ; mean preoperative limb alignment was 166.7 degrees . Three limbs underwent simultaneous corrective osteotomy; the rest were treated with intra-articular correction during computer-assisted total knee arthroplasty (TKA). Mean postoperative limb alignment was 179.1 degrees . At a mean follow-up of 26.4 months, the Knee Society knee score improved from a mean preoperative score of 49.7 to 90.4 points postoperatively; function score improved from 47.3 to 84.9 points. Computer-assisted TKA is a useful alternative to conventional TKA for knee arthritis with extra-articular deformity where accurate restoration of limb alignment may be challenging because of the presence of a deformed tibia or femur or in the presence of hardware.

  12. Relief of knee flexion contracture and gait improvement following adaptive training for an assist device in a transtibial amputee: A case study.

    PubMed

    Kim, Sol-Bi; Ko, Chang-Yong; Son, Jinho; Kang, Sungjae; Ryu, Jeicheong; Mun, Museong

    2017-01-01

    Management of a knee contracture is important for regaining gait ability in transtibial amputees. However, there has been little study of prosthesis training for enhancing mobility and improving range of motion in cases of restricted knee extension. This study aimed to evaluate the effects of adaptive training for an assist device (ATAD) for a transtibial amputee with a knee flexion contracture (KFC). A male transtibial amputee with KFC performed 4 months of ATAD with a multidisciplinary team. During the ATAD, the passive range of motion (PROM) in the knee, amputee mobility predictor (AMP) assessment, center of pressure (COP) on a force plate-equipped treadmill, gait features determined by three-dimensional motion analysis, and Short-Form 36 Item Health Survey (SF-36) scores were evaluated. Following ATAD, PROM showed immediate improvement (135.6 ± 2.4° at baseline, 142.5 ± 1.7° at Step 1, 152.1 ± 1.8° at Step 2, 165.8 ± 1.9° at Step 3, and 166.0 ± 1.4° at Step 4); this was followed by an enhanced COP. Gradually, gait features also improved. Additionally, the AMP score (5 at baseline to 29 at Step 4) and K-level (K0 at baseline to K3 at Step 4) increased after ATAD. Along with these improvements, the SF-36 score also improved. ATAD could be beneficial for transtibial amputees by relieving knee contractures and improving gait.

  13. Hemi-wedge osteotomy in the management of large angular deformities around the knee joint.

    PubMed

    El-Alfy, Barakat Sayed

    2016-08-01

    Angular deformity around the knee joint is a common orthopedic problem. Many options are available for the management of such problem with varying degrees of success and failure. The aim of the present study was to assess the results of hemi-wedge osteotomy in the management of big angular deformities about the knee joint. Twenty-eight limbs in 21 patients with large angular deformities around the knee joint were treated by the hemi-wedge osteotomy technique. The ages ranged from 12 to 43 years with an average of 19.8 years. The deformity ranged from 20° to 40° with a mean of 30.39° ± 5.99°. The deformities were genu varum in 12 cases and genu valgum in 9 cases. Seven cases had bilateral deformities. Small wedge was removed from the convex side of the bone and put in the gap created in the other side after correction of the deformity. At the final follow-up, the deformity was corrected in all cases except two. Full range of knee movement was regained in all cases. The complications included superficial wound infection in two cases, overcorrection in one case, pain along the lateral aspect of the knee in one case and recurrence of the deformity in one case. No cases were complicated by nerve injury or vascular injury. Hemi-wedge osteotomy is a good method for treatment of deformities around the knee joint. It can correct large angular deformities without major complications.

  14. Effects of Reduction Osteotomy on Gap Balancing During Total Knee Arthroplasty for Severe Varus Deformity.

    PubMed

    Niki, Yasuo; Harato, Kengo; Nagai, Katsuya; Suda, Yasunori; Nakamura, Masaya; Matsumoto, Morio

    2015-12-01

    This study aimed to assess the effects of down-sizing and lateralizing of the tibial component (reduction osteotomy) on gap balancing in TKA, and the clinical feasibility of an uncemented modular trabecular metal tibial tray in this technique. Reduction osteotomy was performed for 39 knees of 36 patients with knee OA with a mean tibiofemoral angle of 21° varus. In 20 knees, appropriate gap balance was achieved by release of the deep medial collateral ligament alone. Flexion gap imbalance could be reduced by approximately 1.7° and 2.8° for 4-mm osteotomy and 8-mm osteotomy, respectively. Within the first postoperative year, clinically-stable tibial component subsidence was observed in 9 knees, but it was not progressive, and the clinical results were excellent at a mean follow-up of 3.3 years.

  15. Factors affecting angular deformities of the knees in Nigerian children--Ilorin experience.

    PubMed

    Agaja, S B

    2001-01-01

    44 children with angular knee deformities were studied at the University of Ilorin Teaching Hospital from September 1994 to December, 1997. There were 19 males (43.2%) and 25 females (56.8%). The commonest age range was 0-5 years age range (81.5%). Bilateral angular deformities are more common than unilateral angular deformities. Windswept deformities accounted for 16 cases(36.4%), bilateral Genu Varum accounted for 15 cases (34.0%), and unilateral Genu Valgum, 8 cases (18.2%). It was found in the study that 40 cases (90.9%) were from urban communities while 4 cases (9.1%) were from rural communities. The angular knee deformities affect both Christian and Moslem children alike; however, the environmental factor is the restriction of children indoors which is a serious factor in the causation of Nutritional Rickets. Angular deformities of the knee were far more common amongst urban dwellers than in children from rural area (Ratio 10:1) while involvement of both knees (88.6%) simultaneously is also more common than single knee involvement (11.4%). Some of the objectives of the investigation were to find out the implications of the angular deformities to parents and children; and ways to prevent occurrence were also discussed in this paper.

  16. Passive knee kinematics before and after total knee arthroplasty: are we correcting pathologic motion?

    PubMed

    Mihalko, William M; Ali, Mounawar; Phillips, Matthew J; Bayers-Thering, Mary; Krackow, Kenneth A

    2008-01-01

    The change in coronal plane deformity throughout a range of flexion before and after total knee arthroplasty (TKA) has not been reported. Unlike most alignment assessments traditionally reporting coronal plane alignment in a standing position under static conditions, this study reports deformity throughout the flexion arc before and after deformity correction. One hundred fifty-two TKA patients using the anteroposterior axis for femoral component rotation and computer navigation techniques were included in the study. Deformity before TKA ranged from 17.5 degrees varus (deformity apex away from the midline) to 20.5 degrees valgus (deformity apex toward the midline) in full extension. Before TKA, deformity was not constant through an arc of motion and significantly decreased with flexion of 60 degrees and more (P < .01). The deformity after performing a TKA was not different (P = .478) throughout the flexion arc. The data determined that deformity is not constant throughout flexion in osteoarthritic knees preoperatively and that deformity throughout flexion can be corrected with the use of conventional alignment techniques during TKA.

  17. The choice of a constitutive formulation for modeling limb flexion-induced deformations and stresses in the human femoropopliteal arteries of different ages.

    PubMed

    Desyatova, Anastasia; MacTaggart, Jason; Poulson, William; Deegan, Paul; Lomneth, Carol; Sandip, Anjali; Kamenskiy, Alexey

    2016-11-21

    Open and endovascular treatments for peripheral arterial disease are notorious for high failure rates. Severe mechanical deformations experienced by the femoropopliteal artery (FPA) during limb flexion and interactions between the artery and repair materials play important roles and may contribute to poor clinical outcomes. Computational modeling can help optimize FPA repair, but these simulations heavily depend on the choice of constitutive model describing the arterial behavior. In this study finite element model of the FPA in the standing (straight) and gardening (acutely bent) postures was built using computed tomography data, longitudinal pre-stretch and biaxially determined mechanical properties. Springs and dashpots were used to represent surrounding tissue forces associated with limb flexion-induced deformations. These forces were then used with age-specific longitudinal pre-stretch and mechanical properties to obtain deformed FPA configurations for seven age groups. Four commonly used invariant-based constitutive models were compared to determine the accuracy of capturing deformations and stresses in each age group. The four-fiber FPA model most accurately portrayed arterial behavior in all ages, but in subjects younger than 40 years, the performance of all constitutive formulations was similar. In older subjects, Demiray (Delfino) and classic two-fiber Holzapfel-Gasser-Ogden formulations were better than the Neo-Hookean model for predicting deformations due to limb flexion, but both significantly overestimated principal stresses compared to the FPA or Neo-Hookean models.

  18. Growth arrest of the proximal tibial physis with recurvatum and valgus deformity of the knee.

    PubMed

    Domzalski, Marcin; Mackenzie, William

    2009-10-01

    Two cases of asymmetrical closure of the proximal tibial epiphysis without a clear aetiological factor were presented. In both cases premature closure of the growth plate resulted in progressive recurvatum and valgus deformity of the knee with leg length discrepancy. The correction of deformity was obtained using Taylor Spatial frame with excellent results at 2 years follow-up. We hypothesize that repetitive trauma or chronic overloading during sports activities might be a factor of growth arrest in reported cases. Orthopedic surgeons should be aware of the possibility of subtle physeal injuries, causing angular deformities, in the cases of even minor knee trauma in skeletally immature population.

  19. A Novel Medial Soft Tissue Release Method for Varus Deformity during Total Knee Arthroplasty: Femoral Origin Release of the Medial Collateral Ligament

    PubMed Central

    Lee, Seung-Yup; Yang, Jae-Hyuk; Lee, Yong-In

    2016-01-01

    Introduction Numerous methods of medial soft tissue release for severe varus deformity during total knee arthroplasty (TKA) have been reported. These include tibial stripping of the superficial medial collateral ligament (MCL), pie-crusting technique, and medial epicondylar osteotomy. However, there are inherent disadvantages in these techniques. Authors hereby present a novel quantitative method: femoral origin release of the medial collateral ligament (FORM). Surgical Technique For medial tightness remaining even after the release of the deep MCL and semimembranosus, the FORM is initiated with identification of the femoral insertion area of the MCL with the knee in flexion. Starting from the most posterior part of the femoral insertion, one third of the MCL femoral insertion is released from its attachment. If necessary, further sequential medial release is performed. Materials and Methods Seventeen knees that underwent the FORM were evaluated for radiological and clinical outcomes. Results Regardless of the extent of the FORM, no knees showed residual valgus instability at 24 weeks after surgery. Conclusions As the FORM is performed in a stepwise manner, fine adjustment during medial release might be beneficial to prevent inadvertent over-release of the medial structures of the knee. PMID:27274473

  20. The Effect of Malrotation of Tibial Component of Total Knee Arthroplasty on Tibial Insert during High Flexion Using a Finite Element Analysis

    PubMed Central

    Todo, Mitsugu

    2014-01-01

    One of the most common errors of total knee arthroplasty procedure is a malrotation of tibial component. The stress on tibial insert is closely related to polyethylene failure. The objective of this study is to analyze the effect of malrotation of tibial component for the stress on tibial insert during high flexion using a finite element analysis. We used Stryker NRG PS for analysis. Three different initial conditions of tibial component including normal, 15° internal malrotation, and 15° external malrotation were analyzed. The tibial insert made from ultra-high-molecular-weight polyethylene was assumed to be elastic-plastic while femoral and tibial metal components were assumed to be rigid. Four nonlinear springs attached to tibial component represented soft tissues around the knee. Vertical load was applied to femoral component which rotated from 0° to 135° while horizontal load along the anterior posterior axis was applied to tibial component during flexion. Maximum equivalent stresses on the surface were analyzed. Internal malrotation caused the highest stress which arose up to 160% of normal position. External malrotation also caused higher stress. Implanting prosthesis in correct position is important for reducing the risk of abnormal wear and failure. PMID:24895658

  1. Selective lengthening of the psoas and rectus femoris and preservation of the iliacus for flexion deformity of the hip in cerebral palsy patients.

    PubMed

    Matsuo, T; Hara, H; Tada, S

    1987-01-01

    Between 1978 and 1983, 52 Japanese patients with cerebral palsy underwent operative correction of flexion deformity of the hip. The results of lengthening of the psoas, rectus femoris, and proximal hamstrings were satisfactory. The iliacus was left intact. Improvement in gait and activities of daily living was attained. Concentric reduction was obtained in 27 of 33 dislocated or subluxated hips. Sitting and perineal care were facilitated, and pain was alleviated. We conclude that preservation of the iliacus is important.

  2. Optimising Ankle Foot Orthoses for children with Cerebral Palsy walking with excessive knee flexion to improve their mobility and participation; protocol of the AFO-CP study

    PubMed Central

    2013-01-01

    Background Ankle-Foot-Orthoses with a ventral shell, also known as Floor Reaction Orthoses (FROs), are often used to reduce gait-related problems in children with spastic cerebral palsy (SCP), walking with excessive knee flexion. However, current evidence for the effectiveness (e.g. in terms of walking energy cost) of FROs is both limited and inconclusive. Much of this ambiguity may be due to a mismatch between the FRO ankle stiffness and the patient’s gait deviations. The primary aim of this study is to evaluate the effect of FROs optimised for ankle stiffness on the walking energy cost in children with SCP, compared to walking with shoes alone. In addition, effects on various secondary outcome measures will be evaluated in order to identify possible working mechanisms and potential predictors of FRO treatment success. Method/Design A pre-post experimental study design will include 32 children with SCP, walking with excessive knee flexion in midstance, recruited from our university hospital and affiliated rehabilitation centres. All participants will receive a newly designed FRO, allowing ankle stiffness to be varied into three configurations by means of a hinge. Gait biomechanics will be assessed for each FRO configuration. The FRO that results in the greatest reduction in knee flexion during the single stance phase will be selected as the subject’s optimal FRO. Subsequently, the effects of wearing this optimal FRO will be evaluated after 12–20 weeks. The primary study parameter will be walking energy cost, with the most important secondary outcomes being intensity of participation, daily activity, walking speed and gait biomechanics. Discussion The AFO-CP trial will be the first experimental study to evaluate the effect of individually optimised FROs on mobility and participation. The evaluation will include outcome measures at all levels of the International Classification of Functioning, Disability and Health, providing a unique set of data with which to

  3. Optimising Ankle Foot Orthoses for children with cerebral palsy walking with excessive knee flexion to improve their mobility and participation; protocol of the AFO-CP study.

    PubMed

    Kerkum, Yvette L; Harlaar, Jaap; Buizer, Annemieke I; van den Noort, Josien C; Becher, Jules G; Brehm, Merel-Anne

    2013-02-01

    Ankle-Foot-Orthoses with a ventral shell, also known as Floor Reaction Orthoses (FROs), are often used to reduce gait-related problems in children with spastic cerebral palsy (SCP), walking with excessive knee flexion. However, current evidence for the effectiveness (e.g. in terms of walking energy cost) of FROs is both limited and inconclusive. Much of this ambiguity may be due to a mismatch between the FRO ankle stiffness and the patient's gait deviations.The primary aim of this study is to evaluate the effect of FROs optimised for ankle stiffness on the walking energy cost in children with SCP, compared to walking with shoes alone. In addition, effects on various secondary outcome measures will be evaluated in order to identify possible working mechanisms and potential predictors of FRO treatment success. A pre-post experimental study design will include 32 children with SCP, walking with excessive knee flexion in midstance, recruited from our university hospital and affiliated rehabilitation centres. All participants will receive a newly designed FRO, allowing ankle stiffness to be varied into three configurations by means of a hinge. Gait biomechanics will be assessed for each FRO configuration. The FRO that results in the greatest reduction in knee flexion during the single stance phase will be selected as the subject's optimal FRO. Subsequently, the effects of wearing this optimal FRO will be evaluated after 12-20 weeks. The primary study parameter will be walking energy cost, with the most important secondary outcomes being intensity of participation, daily activity, walking speed and gait biomechanics. The AFO-CP trial will be the first experimental study to evaluate the effect of individually optimised FROs on mobility and participation. The evaluation will include outcome measures at all levels of the International Classification of Functioning, Disability and Health, providing a unique set of data with which to assess relationships between outcome

  4. Fixed-flexion knee radiography using a new positioning device produced highly repeatable measurements of joint space width: ELSA-Brasil Musculoskeletal Study (ELSA-Brasil MSK).

    PubMed

    Telles, Rosa Weiss; Costa-Silva, Luciana; Machado, Luciana A C; Reis, Rodrigo Citton Padilha Dos; Barreto, Sandhi Maria

    To describe the performance of a non-fluoroscopic fixed-flexion PA radiographic protocol with a new positioning device, developed for the assessment of knee osteoarthritis (OA) in Brazilian Longitudinal Study of Adult Health Musculoskeletal Study (ELSA-Brasil MSK). A test-retest design including 19 adults (38 knee images) was conducted. Feasibility of the radiographic protocol was assessed by image quality parameters and presence of radioanatomic alignment according to intermargin distance (IMD) values. Repeatability was assessed for IMD and joint space width (JSW) measured at three different locations. Approximately 90% of knee images presented excellent quality. Frequencies of nearly perfect radioanatomic alignment (IMD ≤1mm) ranged from 29% to 50%, and satisfactory alignment was found in up to 71% and 76% of the images (IMD ≤1.5mm and ≤1.7mm, respectively). Repeatability analyses yielded the following results: IMD [SD of mean difference=1.08; coefficient of variation (%CV)=54.68%; intraclass correlation coefficient (ICC) (95%CI)=0.59 (0.34-0.77)]; JSW [SD of mean difference=0.34-0.61; %CV=4.48%-9.80%; ICC (95%CI)=0.74 (0.55-0.85)-0.94 (0.87-0.97)]. Adequately reproducible measurements of IMD and JSW were found in 68% and 87% of the images, respectively. Despite the difficulty in achieving consistent radioanatomic alignment between subsequent radiographs in terms of IMD, the protocol produced highly repeatable JSW measurements when these were taken at midpoint and 10mm from the medial extremity of the medial tibial plateau. Therefore, measurements of JSW at these locations can be considered adequate for the assessment of knee OA in ELSA-Brasil MSK. Copyright © 2016. Published by Elsevier Editora Ltda.

  5. Fixed-flexion knee radiography using a new positioning device produced highly repeatable measurements of joint space width: ELSA-Brasil Musculoskeletal Study (ELSA-Brasil MSK).

    PubMed

    Telles, Rosa Weiss; Costa-Silva, Luciana; Machado, Luciana A C; Reis, Rodrigo Citton Padilha Dos; Barreto, Sandhi Maria

    2016-11-26

    To describe the performance of a non-fluoroscopic fixed-flexion PA radiographic protocol with a new positioning device, developed for the assessment of knee osteoarthritis (OA) in ELSA-Brasil MSK. A test-retest design including 19 adults (38 knee images) was conducted. Feasibility of the radiographic protocol was assessed by image quality parameters and presence of radioanatomic alignment according to intermargin distance (IMD) values. Repeatability was assessed for IMD and joint space width (JSW) measured at three different locations. Approximately 90% of knee images presented excellent quality. Frequencies of nearly perfect radioanatomic alignment (IMD ≤1mm) ranged from 29% to 50%, and satisfactory alignment was found in up to 71% and 76% of the images (IMD ≤1.5mm and ≤1.7mm, respectively). Repeatability analyses yielded the following results: IMD [SD of mean difference=1.08; coefficient of variation (%CV)=54.68%; intraclass correlation coefficient (ICC) (95%CI)=0.59 (0.34-0.77)]; JSW [SD of mean difference=0.34 - 0.61; %CV=4.48% - 9.80%; ICC (95%CI)=0.74 (0.55-0.85) - 0.94 (0.87-0.97)]. Adequately reproducible measurements of IMD and JSW were found in 68% and 87% of the images, respectively. Despite the difficulty in achieving consistent radioanatomic alignment between subsequent radiographs in terms of IMD, the protocol produced highly repeatable JSW measurements when these were taken at midpoint and 10mm from the medial extremity of the medial tibial plateu. Therefore, measurements of JSW at these locations can be considered adequate for the assessment of knee OA in ELSA-Brasil MSK. Copyright © 2016. Published by Elsevier Editora Ltda.

  6. Effects of knee flexion angle and loading conditions on the end-to-end distance of the posterior cruciate ligament: a comparison of the roles of the anterolateral and posteromedial bundles.

    PubMed

    Wang, Joon Ho; Kato, Yuki; Ingham, Sheila J M; Maeyama, Akira; Linde-Rosen, Monica; Smolinski, Patrick; Fu, Freddie H; Harner, Christopher

    2014-12-01

    It is commonly accepted that the anterolateral (AL) bundle of the posterior cruciate ligament (PCL) is tight in flexion and that the posteromedial (PM) bundle is tight in extension. However, a recent in vivo study showed that both bundles were tight in extension. To investigate the effects of knee flexion angle, rotational torque, and anterior/posterior translational force on the end-to-end distance between the femoral and tibial insertion sites of each bundle of the PCL. Descriptive laboratory study. Cadaveric knees (10 specimens) were mounted on a robotic system, and the relative positional data between the femur and tibia were acquired during passive flexion/extension, with an applied 5-N·m rotational torque and an applied 89-N translational force. The bony surface and PCL insertion data were acquired with a 3-dimensional scanner after gross dissection and were superimposed onto the positional data. The end-to-end distance between the 2 PCL insertion sites of the femur and tibia was measured. The end-to-end distance increased from full extension to 90° for both the AL (9.2 ± 1.8 mm; from 30.0 to 39.2 mm) and PM bundles (5.8 ± 2.2 mm; from 32.0 to 37.7 mm). With an internal rotational torque, the end-to-end distance of the PM bundle increased significantly (P < .05) at 0°, 30°, and 60° of knee flexion. Under a posterior translational force at 90° of knee flexion, the length of both bundles increased to their longest measurements (AM bundle: 40.6 ± 4.2 mm; PM bundle: 38.4 ± 3.8 mm). The end-to-end distance of the AL and PM bundles of the PCL increased in flexion, and this pattern was maintained during tests with posterior translational force. The PM bundle was more affected by the rotational torque than was the AL bundle. Both bundles of the PCL may serve a greater functional role in flexion than in extension. The PM bundle might be more important for the control of rotation than the AL bundle. Posterior translation at 90° of knee flexion could be the

  7. Varus-valgus stability at 90° flexion correlates with the stability at midflexion range more widely than that at 0° extension in posterior-stabilized total knee arthroplasty.

    PubMed

    Hino, Kazunori; Kutsuna, Tatsuhiko; Watamori, Kunihiko; Kiyomatsu, Hiroshi; Ishimaru, Yasumitsu; Takeba, Jun; Watanabe, Seiji; Shiraishi, Yoshitaka; Miura, Hiromasa

    2017-08-28

    Midflexion stability can potentially improve the outcome of total knee arthroplasty (TKA). The purpose of this study was to evaluate the correlation between varus-valgus stability at 0° of extension and 90° of flexion and that at the midflexion range in posterior-stabilized (PS)-TKA. Forty-three knees that underwent PS-TKA were evaluated. Manual mild passive varus-valgus stress was applied to the knees, and the postoperative maximum varus-valgus stability was measured every 10° throughout range of motion, using a navigation system. Correlations between the stability at 0°, 90° of flexion, and that at each midflexion angle were evaluated using Spearman's correlation coefficients. The stability of 0° modestly correlated with that of 10°-20°, but it did not significantly correlate with that of 30°-80°. However, the stability of 90° strongly correlated with that of 60°-80°, modestly correlated with that of 40°-50°, weakly correlated with that of 20°-30°, and did not correlate with that of 10°. The present study confirmed the importance of acquiring stability at 90° flexion to achieve midflexion stability in PS-TKA. However, initial flexion stability did not strongly correlate with the stability at either 0° or 90°. Our findings can provide useful information for understanding varus-valgus stability throughout the range of motion in PS-TKA. Attention to soft tissue balancing is necessary to stabilize a knee at the initial flexion range in PS-TKA.

  8. Congenital dislocation of the knee in a 16-year-old girl.

    PubMed

    Kazemi, Seyyed Morteza; Abbasian, Mohammad Reza; Hosseinzadeh, Hamid Reza Seyyed; Zanganeh, Ramin Farhang; Eajazi, Alireza; Daftari Besheli, Laleh

    2010-05-12

    Congenital dislocation of the knee ranges from hyperextension of the knee to translation of the femur on the tibia. Treatment options include bracing, splinting, manipulation and casting, and surgery. A 16-year-old girl presented with an inability to walk, stand upright, or bend her knees. She exhibited deformity of both lower extremities. She had deformed knees from birth, and they had been put in a cast for 2 months. No other therapeutic measures were taken. The patient walked on her abnormally hyperextended knees and could hyperextend the knees to 150 degrees recurvatum. She was diagnosed with a grade III congenital dislocation of the knee, and a flexion-shortening osteotomy at the distal femur above the trochlear level was performed on her knees in 2 sessions. Postoperatively, range of motion changed from hyperextention to 80 degrees flexion. A femoral supracondylar osteotomy was also performed 2 years later, and as a result, a 15 degrees flexion and 15 degrees valgus were added to the limb. The patient is now able to stand and walk without a knee brace and has 90 degrees passive and 80 degrees active knee flexion on both sides. Congenital dislocation of the knee is a rare congenital disorder. The results of treatment are favorable if started before age 3 months, or sometimes before age 2 years, but there is no effective treatment for older, neglected cases; therefore, we believe this case report demonstrates a novel surgical approach. Copyright 2010, SLACK Incorporated.

  9. Shortening femoral osteotomy with stemmed resurfacing total knee arthroplasty for severe flexion contracture in Juvenile Rheumatoid Arthritis.

    PubMed

    Kitchen, Brock; Sanchez, Hugo B; Wagner, Russell A

    2015-06-01

    Juvenile Rheumatoid Arthritis (JRA) is a progressive disease characterized by pain, swelling, and loss of motion in the joints of adolescents. Total knee arthroplasty (TKA) can be indicated, during the adolescent years, in patients with advanced JRA to alleviate pain and improve function. Because of the relative infrequency of TKA in patients with JRA, evaluation of the type of TKA performed and the results merit review. This case report present two distinct operations performed to obtain full extension. 1. Distal femoral resection with conversion to hinged arthroplasty. 2. Femoral shortening osteotomy with resurfacing TKA.

  10. Shortening femoral osteotomy with stemmed resurfacing total knee arthroplasty for severe flexion contracture in Juvenile Rheumatoid Arthritis

    PubMed Central

    Kitchen, Brock; Sanchez, Hugo B.; Wagner, Russell A.

    2015-01-01

    Juvenile Rheumatoid Arthritis (JRA) is a progressive disease characterized by pain, swelling, and loss of motion in the joints of adolescents. Total knee arthroplasty (TKA) can be indicated, during the adolescent years, in patients with advanced JRA to alleviate pain and improve function. Because of the relative infrequency of TKA in patients with JRA, evaluation of the type of TKA performed and the results merit review. This case report present two distinct operations performed to obtain full extension. 1. Distal femoral resection with conversion to hinged arthroplasty. 2. Femoral shortening osteotomy with resurfacing TKA. PMID:25972704

  11. Probability of mechanical loosening of the femoral component in high flexion total knee arthroplasty can be reduced by rather simple surgical techniques.

    PubMed

    van de Groes, S; de Waal-Malefijt, M; Verdonschot, N

    2014-01-01

    Some follow-up studies of high flexion total knee arthoplasties report disturbingly high incidences of femoral component loosening. Femoral implant fixation is dependant on two interfaces: the cement-implant and the cement-bone interface. The present finite-element model (FEM) is the first to analyse both the cement-implant interface and cement-bone interface. The cement-bone interface is divided into cement-cancellous and cement-cortical bone interfaces, each having their own strength values. The research questions were: (1) which of the two interfaces is more prone to failure? and (2) what is the effect of different surgical preparation techniques for cortical bone on the risk of early failure.? FEM was used in which the posterior-stabilized PFC Sigma RP-F (DePuy) TKA components were incorporated. A full weight-bearing squatting cycle was simulated (ROM=50°-155°). An interface failure index (FI) was calculated for both interfaces. The cement-bone interface is more prone to failure than the cement implant interface. When drilling holes through the cortex behind the anterior flange instead of unprepared cortical bone, the area prone to early interface failure can be reduced from 31.3% to 2.6%. The results clearly demonstrate high risk of early failure at the cement-bone interface. This risk can be reduced by some simple preparation techniques of the cortex behind the anterior flange. High-flexion TKA is currently being introduced. Some reports show high failure rates. FEM can be helpful in understanding failure of implants. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Reliability of Concentric, Eccentric and Isometric Knee Extension and Flexion when using the REV9000 Isokinetic Dynamometer.

    PubMed

    de Carvalho Froufe Andrade, Alberto César Pereira; Caserotti, Paolo; de Carvalho, Carlos Manuel Pereira; de Azevedo Abade, Eduardo André; da Eira Sampaio, António Jaime

    2013-01-01

    The aim of this study was to assess the reliability of isokinetic and ISO knee extensor and flexor muscle strength when using the REV9000 (Technogym) isokinetic dynamometer. Moreover, the reliability of several strength imbalance indices and bilateral ratios were also examined. Twenty-four physically active healthy subjects (age 23±3 years) underwent three testing sessions, two on the same day and a third, 7 days later. All sessions proceeded in the same order: five concentric contractions at 60ºs-1 followed by an isometric contraction (5 seconds) and five eccentric contractions (60ºs-1). The results of this study showed a high reproducibility in eccentric (0.95-0.97), concentric (0.95-0.96) and isometric (0.93-0.96), isokinetic strength for knee extensor and flexor muscles, thus indicating that the REV9000 isokinetic dynamometer can be used in future sports performance studies. A low-to-moderate reliability was found in the isokinetic strength bilateral ratios while the Hamstring:Quadricep concentric ratio showed moderate reliability. The highest reliability (>0.90) was observed in the dynamic control ratio (Hamstring eccentric:Quadricep concentric) which consequently confirms that it is a more valid indicator for imbalanced reciprocal parameters and can be used in rehabilitation and sports medicine.

  13. Radiological and clinical effect of prosthesis design in varus knees?

    PubMed Central

    Isyar, Mehmet; Guler, Olcay; Cakmak, Selami; Kara, Adnan; Yalcin, Sercan; Mahirogullari, Mahir

    2015-01-01

    Purpose The aim of the study is to investigate the efficacy of the prosthesis design used in total knee arthroplasty in patients with varus malalignment. Methods After exclusion criteria we classified 90 patients underwent total knee arthroplasty according to prosthesis used into two groups: posterior cruciate ligament substituting and retaining. Mean follow up period was 25–98 months. We evaluated preoperative and postoperative radiological and as well as clinical parameters such as pain, knee function, flexion deformity. Results We found statistically significant difference in both groups in terms of deformity correction (p = 0.000). Conclusion Prosthesis design affects radiological outcomes in varus knees. PMID:26566321

  14. [Posttraumatic deformities of the knee joint : Intra-articular osteotomy after malreduction of tibial head fractures].

    PubMed

    Frosch, K-H; Krause, M; Frings, J; Drenck, T; Akoto, R; Müller, G; Madert, J

    2016-10-01

    Malreduction of tibial head fractures often leads to malalignment of the lower extremity, pain, limited range of motion and instability. The extent of the complaints and the degree of deformity requires an exact analysis and a standardized approach. True ligamentous instability should be distinguished from pseudoinstability of the joint. Also extra- and intra-articular deformities have to be differentiated. In intra-articular deformities the extent of articular surface displacement, defects and clefts must be accurately evaluated. A specific surgical approach is necessary, which allows adequate visualization, correct osteotomy and refixation of the fractured area of the tibial head. In the long-term course good clinical results are described for intra-articular osteotomies. If the joint is damaged to such an extent that it cannot be reconstructed or in cases of advanced posttraumatic osteoarthritis, total knee arthroplasty may be necessary; however, whenever possible and reasonable, anatomical reconstruction and preservation of the joint should be attempted.

  15. Ambulation gains after knee surgery in children with arthrogryposis.

    PubMed

    Yang, Stephen Su; Dahan-Oliel, Noémi; Montpetit, Kathleen; Hamdy, Reggie C

    2010-12-01

    Arthrogryposis multiplex congenita is a rare congenital disorder associated with multiple musculoskeletal contractures that causes substantial morbidity. Knee involvement is commonly seen among children with arthrogryposis, with flexion contracture of the knee being the most frequent knee deformity. Knee flexion contractures in the pediatric population are particularly debilitating as they affect ambulation. Treatment for knee flexion contractures requires numerous orthopaedic procedures and an extensive follow-up period. The purpose of this study was to assess the effectiveness of orthopaedic procedures, namely distal femoral supracondylar extension osteotomy and/or Ilizarov external fixator, on the ambulation status of children with knee flexion contracture and whether any functional gains are maintained at the latest follow-up. All children with arthrogryposis followed at our institution who had surgical correction for knee flexion contractures were included in this study. Fourteen patients were identified and their medical records were reviewed. The etiology for all patients was amyoplasia. The mean age at first surgery was 7.0 years (range, 2 to 16 y). The mean length of follow-up was 59.3 months (range, 12 to 117 mo). Contractures were treated with femoral extension osteotomy (n=8), Ilizarov external fixator (n=1), or both (n=5). Three patients earlier had posterior soft tissue releases, including hamstrings lengthenings, proximal gastrocnemius release, and release of posterior capsule. Preoperatively, 11 patients were nonambulatory, 2 patients were household ambulators, and 1 patient walked with orthoses in the community. There was an average of 1.8 knee surgeries done per patient, namely distal femoral extension osteotomy and/or Ilizarov external fixator. At the latest follow-up, 8 patients were ambulatory with technical aids (orthosis, walker, braces, or rollator walker), 2 patients were household ambulators, 1 patient used a wheelchair but was independent

  16. Kinematic evaluation of the finger's interphalangeal joints coupling mechanism--variability, flexion-extension differences, triggers, locking swanneck deformities, anthropometric correlations.

    PubMed

    Leijnse, J N A L; Quesada, P M; Spoor, C W

    2010-08-26

    The human finger contains tendon/ligament mechanisms essential for proper control. One mechanism couples the movements of the interphalangeal joints when the (unloaded) finger is flexed with active deep flexor. This study's aim was to accurately determine in a large finger sample the kinematics and variability of the coupled interphalangeal joint motions, for potential clinical and finger model validation applications. The data could also be applied to humanoid robotic hands. Sixty-eight fingers were measured in seventeen hands in nine subjects. Fingers exhibited great joint mobility variability, with passive proximal interphalangeal hyperextension ranging from zero to almost fifty degrees. Increased measurement accuracy was obtained by using marker frames to amplify finger segment motions. Gravitational forces on the marker frames were not found to invalidate measurements. The recorded interphalangeal joint trajectories were highly consistent, demonstrating the underlying coupling mechanism. The increased accuracy and large sample size allowed for evaluation of detailed trajectory variability, systematic differences between flexion and extension trajectories, and three trigger types, distinct from flexor tendon triggers, involving initial flexion deficits in either proximal or distal interphalangeal joint. The experimental methods, data and analysis should advance insight into normal and pathological finger biomechanics (e.g., swanneck deformities), and could help improve clinical differential diagnostics of trigger finger causes. The marker frame measuring method may be useful to quantify interphalangeal joints trajectories in surgical/rehabilitative outcome studies. The data as a whole provide the most comprehensive collection of interphalangeal joint trajectories for clinical reference and model validation known to us to date.

  17. Arthroscopic knee debridement can delay total knee replacement in painful moderate haemophilic arthropathy of the knee in adult patients.

    PubMed

    Rodriguez-Merchan, E Carlos; Gomez-Cardero, Primitivo

    2016-09-01

    The role of arthroscopic debridement of the knee in haemophilia is controversial in the literature. The purpose of this study is to describe the results of arthroscopic knee debridement (AKD), with the aim of determining whether it is possible to delay total knee replacement (TKR) for painful moderate haemophilic arthropathy of the knee in adult patients. In a 14-year period (1998-2011), AKD was performed for moderate haemophilic arthropathy of the knee in 27 patients with haemophilia A. Their average age at operation was 28.6 years (range 26-39 years). Indications for surgery were as follows: more than 90° of knee flexion, flexion deformity less than 30°, good axial alignment of the knee, good patellar alignment, and pain above >60 points in a visual analogue scale [0 (no pain) to 100 points]. Secondary haematological prophylaxis and rehabilitation (physiotherapy) was given for at least 3 months after surgery. Follow-up was for an average of 7.5 years (range 2-14 years). We assessed the clinical outcome before surgery and at the time of latest follow-up using the Knee Society pain and function scores, the range of motion, and the radiological score of the World Federation of Haemophilia. Knee Society pain scores improved from 39 preoperatively to 66 postoperatively, and function scores improved from 36 to 52. Range of motion improved on an average from -15° of extension and 90° of flexion before surgery, to -5° of extension and 110° of flexion at the last follow-up. A radiological deterioration of 2.8 points on average was found. There were two (7.4%) postoperative complications (haemarthroses resolved by joint aspiration). One patient (3.7%) required a TKR 12.5 years later. AKD should be considered in painful moderate haemophilic arthropathy of the knee in adult patients to delay TKR.

  18. [Total knee arthroplasty in severe valgus deformity in a patient with achondroplasia].

    PubMed

    Koudela, K; Koudela, K; Koudelová, J

    2011-01-01

    The authors present the results of total knee replacement in a 66-year-old woman with achondroplasia. The condition was diagnosed on the basis of clinical and radiographic findings; molecular genetic examination confirmed that the patient was heterozygous for the G1138A mutation responsible for substitution of an arginine for a glycine residue at position 380 (G380R). The patient presented with an unusual finding of severe fixed 20-degree valgus deformity, so far not published, which did not conform with the clinical features of achondroplasia. The authors presumed that the deformity had developed due to asymmetric growth of the distal femoral diaphysis resulting in a hypoplastic lateral femoral condyle and, consequently, valgus deformity. They put emphasis on thorough pre-operative radiography in order to define the size of components according to the templates, and on measurement of the valgus angle and femoral mechanical axis. They also drew attention to the problem of an extra-articular tibial alignment guide and recommended the use of its alternative or computer navigation. The surgery restored the mechanical axis, range of motion and stability of the knee, relieved pain and improved walking, which afforded a better quality of life for the patient.

  19. SEVERE VALGUS DEFORMITY OF THE KNEE: DESCRIPTION OF NEW SURGICAL TECHNIQUE FOR ITS CORRECTION

    PubMed Central

    da Silva, Robson Rocha; Matos, Marcos Almeida; Pimentel, Maurício; Martins, Bruno Jacomeli; Oliveira, Rafael Valadares

    2015-01-01

    Varus supracondylar osteotomy of the femur is the established procedure for treating painful knees that present lateral arthrosis and valgus deformity. In descriptions of the conventional surgical techniques, there are divergences regarding the location, access route, correction level, fixation type and area for synthesis insertion. This is most evident in cases of severe valgus with angles greater than 30° and distal femoral deformation, in association with hypoplasia of the lateral condyle. The authors describe a new surgical technique for distal femoral osteotomy, based on anatomical and geometrical criteria, which was developed in their clinic for treating severe valgus cases, and they present one of the cases treated. In the new technique, the wedge to be surgically resected has an oblique direction and the format of an isosceles triangle. This new proposal thus seeks to resolve problems that have been presented in such cases, through enabling valgus correction without causing any new deformity of the distal femur. Good cortical bone contact is promoted, and application of a stable synthesis system is made easier. However, the age limits for such patients and the degree of knee arthrosis that might contraindicate this procedure remain unknown. Hence, a larger sample and longer follow-up for operated cases are required. PMID:27042630

  20. Radiologic Outcomes According to Varus Deformity in Minimally Invasive Surgery Total Knee Arthroplasty

    PubMed Central

    Yoo, Ju-Hyung; Han, Chang-Dong; Oh, Hyun-Cheol; Park, Jun-Young; Choi, Seung-Jin

    2016-01-01

    Purpose To identify the accuracy of postoperative implant alignment in minimally invasive surgery total knee arthroplasty (MIS-TKA), based on the degree of varus deformity. Materials and Methods The research examined 627 cases of MIS-TKA from November 2005 to December 2007. The cases were categorized according to the preoperative degree of varus deformity in the knee joint in order to compare the postoperative alignment of the implant: less than 5° varus (Group 1, 351 cases), 5° to less than 10° varus (Group 2, 189 cases), 10° to less than 15° varus (Group 3, 59 cases), and 15° varus or more (Group 4, 28 cases). Results On average, the alignment of the tibial implant was 0.2±1.4°, 0.1±1.3°, 0.1±1.6°, and 0.3±1.7° varus, and the tibiofemoral alignment was 5.2±1.9°, 4.7±1.9°, 4.9±1.9°, and 5.1±2.0° valgus for Groups 1, 2, 3, and 4, respectively, in the preoperative stage, indicating no difference between the groups (p>0.05). With respect to the accuracy of the tibial implant alignment, 98.1%, 97.6%, 87.5%, and 86.7% of Groups 1, 2, 3, and 4, respectively, had 0±3° varus angulation, demonstrating a reduced level of accuracy in Groups 3 and 4 (p<0.0001). There was no difference in terms of tibiofemoral alignment, with 83.9%, 82.9%, 85.4%, and 86.7% of each group, respectively, showing 6±3° valgus angulation (p>0.05). Conclusion Satisfactory component alignment was achieved in minimally invasive surgery in total knee arthroplasty, regardless of the degree of varus deformity. PMID:26632405

  1. A Maximum Muscle Strength Prediction Formula Using Theoretical Grade 3 Muscle Strength Value in Daniels et al.'s Manual Muscle Test, in Consideration of Age: An Investigation of Hip and Knee Joint Flexion and Extension

    PubMed Central

    Matsumura, Masashi; Ichikawa, Kazuna; Takei, Hitoshi

    2017-01-01

    This study attempted to develop a formula for predicting maximum muscle strength value for young, middle-aged, and elderly adults using theoretical Grade 3 muscle strength value (moment fair: Mf)—the static muscular moment to support a limb segment against gravity—from the manual muscle test by Daniels et al. A total of 130 healthy Japanese individuals divided by age group performed isometric muscle contractions at maximum effort for various movements of hip joint flexion and extension and knee joint flexion and extension, and the accompanying resisting force was measured and maximum muscle strength value (moment max, Mm) was calculated. Body weight and limb segment length (thigh and lower leg length) were measured, and Mf was calculated using anthropometric measures and theoretical calculation. There was a linear correlation between Mf and Mm in each of the four movement types in all groups, excepting knee flexion in elderly. However, the formula for predicting maximum muscle strength was not sufficiently compatible in middle-aged and elderly adults, suggesting that the formula obtained in this study is applicable in young adults only. PMID:28133549

  2. A Maximum Muscle Strength Prediction Formula Using Theoretical Grade 3 Muscle Strength Value in Daniels et al.'s Manual Muscle Test, in Consideration of Age: An Investigation of Hip and Knee Joint Flexion and Extension.

    PubMed

    Usa, Hideyuki; Matsumura, Masashi; Ichikawa, Kazuna; Takei, Hitoshi

    2017-01-01

    This study attempted to develop a formula for predicting maximum muscle strength value for young, middle-aged, and elderly adults using theoretical Grade 3 muscle strength value (moment fair: Mf )-the static muscular moment to support a limb segment against gravity-from the manual muscle test by Daniels et al. A total of 130 healthy Japanese individuals divided by age group performed isometric muscle contractions at maximum effort for various movements of hip joint flexion and extension and knee joint flexion and extension, and the accompanying resisting force was measured and maximum muscle strength value (moment max, Mm ) was calculated. Body weight and limb segment length (thigh and lower leg length) were measured, and Mf was calculated using anthropometric measures and theoretical calculation. There was a linear correlation between Mf and Mm in each of the four movement types in all groups, excepting knee flexion in elderly. However, the formula for predicting maximum muscle strength was not sufficiently compatible in middle-aged and elderly adults, suggesting that the formula obtained in this study is applicable in young adults only.

  3. Neglected surgically intervened bilateral congenital dislocation of knee in an adolescent

    PubMed Central

    Kumar, Jaswant; Dhammi, Ish Kumar; Jain, Anil K

    2014-01-01

    Neglected bilateral congenital dislocation of knee is unusual. A 12 year old boy presented with inability to walk due to buckling of the knee. The symptoms were present since the child learnt walking. He preferred not to walk. Bilateral supracondylar femoral osteotomy was done at the age of 6 years. Patient had a fixed flexion deformity of both knees, 30° in the right (range of flexion from 30° to 45°) and 45° fixed flexion deformity in left knee respectively (range of flexion from 45° to 65°) when presented to us. The radiological examination revealed bilateral congenital dislocation of knee (CDK). No syndromic association was observed. He was planned for staged treatment. In stage I, the knee joints were distracted by Ilizarov ring fixators and this was followed by open reduction of both the knee joints in stage II. A bilateral supracondylar extension osteotomy was done 18 months after the previous surgery (stage III). The final followup visit at 4 years the patient presented with range of motion 5-100° and 5-80° on the right and left knee respectively with good functional outcome. The case is reported in view of lack of treatment guidelines for long standing neglected CDK in an adolescent child. PMID:24600070

  4. [Soft tissue balancing in total condylar knee arthroplasty].

    PubMed

    Trepte, C T; Pfanzelt, K

    2003-01-01

    Soft tissue balancing and correct bone cuts are an entity in correcting malalignment in total knee arthroplasty, and cannot be considered isolated. Distinct bony deformations/deviations need enlarged soft tissue management. The extent of resection of the bone stock has to be planned exactly before the operation. Exact soft tissue balancing is necessary to stabilize the corrected knee. Soft tissue balancing has to be done primarily on the side of the contracture by lengthening of the shortened and contracted structures. After balancing the ligaments should have the same tension in extension and flexion together with the same height of the extension and flexion gap. Because of the classic resection of the tibial head, the femoral resection must follow the Insall-Line, that means 3 degrees to 5 degrees outer rotation in relation to the condyles. Only in this way a symmetric flexion gap can be achieved in combination with ligamentous stability in extension and flexion.

  5. Partial knee replacement

    MedlinePlus

    ... minor deformity in the knee. You have good range of motion in your knee. The ligaments in your knee ... You will also need physical therapy to improve range of motion and strengthen the muscles around the knee.

  6. Osteogenesis imperfecta: a case with hand deformities.

    PubMed

    Oz, Bengi; Olmez, Nese; Memis, Asuman

    2005-09-01

    In a 51-year-old woman with a history of fractures and dislocations after low intensity trauma in childhood, intensive blue sclera, short stature, and hearing loss, the diagnosis of osteogenesis imperfecta (OI) was suspected. She was referred to our clinic with hand deformities and left knee pain and stiffness. She had difficulty in walking and reported a history of immobilization for 6 months because of knee pain. She had bilateral flexion contracture of the elbows which occurred following dislocations of the elbows in childhood. She had Z deformity of the first phalanges, reducible swan-neck deformity of the third finger of the left and the second finger of the right hand, flexion contracture of the proximal interphalangeal joint of the fifth finger of the left hand, and syndactyly of the third and fourth fingers of the right hand. Flexion contractures of both knees were observed. Pes planus and short toes were the deformities of the feet. Acute phase reactants of the patient were normal. She had no history of arthritis or morning stiffness. Bone mineral density evaluated by dual-energy X-ray absorptiometry (DEXA) showed severe osteoporosis of the femur and lumbar vertebrae. She had radiographic evidence of healed fractures of the left fibula, the third metacarpal, and the fourth and fifth middle phalanges of the right hand. OI, affecting the type I collagen tissue of the sclera, skin, ligaments, and skeleton, presenting with ligament laxity resulting in subluxations and hand deformities may be misdiagnosed as hand deformities of rheumatoid arthritis.

  7. Clinical Outcomes of Patients with Valgus Deformity Undergoing Minimally Invasive Total Knee Arthroplasty Through the Medial Approach

    PubMed Central

    Hamahashi, Kosuke; Mitani, Genya; Takagaki, Tomonori; Serigano, Kenji; Mochida, Joji; Sato, Masato; Watanabe, Masahiko

    2016-01-01

    Objective: The purpose of this study was to compare the clinical outcomes between patients with a valgus or varus deformity undergoing minimally invasive total knee arthroplasty through the medial approach. Methods: The patients were classified into 2 groups according to the preoperative femorotibial angle measured on an anteroposterior long leg roentgenogram. The valgus group comprised of 26 knees in 21 patients with a femorotibial angle <170° (163.5 ± 5.7), and the varus group comprised of 24 knees in 21 patients with a femorotibial angle >190° (195.9 ± 5.5). The following background variables were compared between the groups: age at the time of the operation, sex, causative disease, preoperative femoral mechanical–anatomical angle, and postoperative knee range of motion, Knee Society score, femorotibial angle, and implant position. Results: There were significant differences between the valgus and varus groups in the age (68.0 ± 6.9 vs 75.8 ± 6.2 years), percentage of males (23.8% vs 0%), percentage with rheumatoid arthritis (61.9% vs 4.8%), and preoperative femoral mechanical–anatomical angle (6.2 ± 1.0° vs 7.4 ± 2.1°). Clinical outcome variables of postoperative femorotibial angle (173.1 ± 3.9° vs 175.2 ± 1.6°) and α angle (96.6 ± 3.1° vs 95.0 ± 1.9°) also differed. Conclusion: It was assumed that over-valgus resection of the femur is a contributory factor to residual valgus alignment. However, knee range of motion and Knee Society score did not differ between the groups. We suggest that minimally invasive total knee arthroplasty through the medial approach is one of the treatment options for patients with valgus deformity. PMID:28144381

  8. Guided growth with a noncannulated screw-plate system for angular deformity of the knee: a preliminary report.

    PubMed

    Lee, Hyun-Joo; Oh, Chang-Wug; Song, Kwang-Soon; Kyung, Hee-Soo; Min, Woo-Kie; Park, Byung-Chul

    2012-07-01

    We assessed the result of guided growth for an angular knee deformity using a 3.5-mm noncannulated screw-plate system. Twenty-seven patients with angular deformities (10 distal femora, 13 proximal tibiae, and four both areas) underwent this procedure with the reconstruction plate and two noncannulated screws. Average age at the time of the procedure was 7.8 years and the average follow-up was 25.7 months. Except for one patient (two knees), 25 of 27 deformities showed a resolved outcome with a neutral alignment. The mechanical lateral distal femoral angle changed an average of 8.3° for 13 months and the medial proximal tibial angle changed an average of 7.7° for 11.8 months in the neutral state. The mean angle between the two screws was -2° in immediate postoperative radiographs and 23° in radiographs taken at the latest follow-up. Two patients showed a rebound outcome and one showed a failure of no correction. There was a superficial infection, but no mechanical failure of the screw and the plate was observed. The noncannulated screw-plate system may play a similar role of guided growth, to correct angular knee deformity, although a large series study with a long follow-up is required for a definitive conclusion.

  9. Magnitude of Deformity Correction May Influence Recovery of Quadriceps Strength After Total Knee Arthroplasty.

    PubMed

    Loyd, Brian J; Jennings, Jason M; Falvey, Jason R; Kim, Raymond H; Dennis, Douglas A; Stevens-Lapsley, Jennifer E

    2017-09-01

    Malalignment of the lower extremity is commonly seen in patients with severe osteoarthritis undergoing total knee arthroplasty (TKA) and is believed to play a role in quadriceps strength loss. Deformity correction is typically achieved through surgical techniques to provide appropriate ligamentous balancing. Therefore, this study examined the influence of change in lower extremity alignment on quadriceps strength outcomes after TKA. Seventy-three participants (36 male; mean age, 62 years; and mean body mass index, 29.7 kg/m(2)) undergoing primary unilateral TKA were used in this investigation. Before surgery and at 1 and 6 months after surgery, measures of isometric knee extensor strength, quadriceps activation, and long-standing plain films were collected. Using the films, measures of mechanical axis, distal femoral angle (DFA), proximal tibial angle, and patellofemoral angle were performed. Hierarchical linear regression was used to evaluate how change in alignment from baseline to 1 and 6 months influenced the change in quadriceps strength. DFA was found to significantly contribute to changes in quadriceps strength at 1 and 6 months after TKA above those contributed by associated covariates. None of the other measures of lower extremity alignment were found to contribute to quadriceps strength in this sample. Reductions in quadriceps strength experienced after TKA are likely to be influenced by changes in lower extremity alignment. Specifically, measures of DFA were found to significantly contribute to these changes. Future work is needed to prospectively examine measures of lower extremity alignment change and recovery after TKA. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Deformity correction of knee and leg lengthening by Ilizarov method in hypophosphatemic rickets: outcomes and significance of serum phosphate level.

    PubMed

    Choi, In Ho; Kim, Jae Kwang; Chung, Chin Youb; Cho, Tae-Joon; Lee, Seok Hyun; Suh, Seong Woo; Whang, Kuhn Sung; Park, Hui Wan; Song, Kwang Soon

    2002-01-01

    The authors evaluated 14 patients with hypophosphatemic rickets who underwent correction of a knee deformity along with a leg lengthening by the Ilizarov method. Deformity correction alone was performed in 8 femora and 4 tibiae-fibulae, and concomitant deformity correction and limb lengthening (>1.0 cm) in 9 femora and 19 tibiae-fibulae. The healing index correlated with the biochemical parameters. Knee deformities were satisfactorily corrected in all patients except one. There was a statistically significant negative correlation between the healing index and the serum phosphate level: those who had a serum phosphate level higher than 2.5 mg/dL showed a relatively rapid regenerate bone healing compared with those with less than 2.5 mg/dL. The authors conclude that a serum phosphate level of 2.5 mg/dL as a cut-off point should be considered in deciding whether deformity correction alone or with a concomitant leg lengthening should be undertaken.

  11. Lengthening and deformity correction about the knee using a magnetic internal lengthening nail

    PubMed Central

    Fragomen, Austin T.; Rozbruch, S. Robert

    2017-01-01

    Introduction: The introduction of the internal lengthening nail (ILN) has changed the treatment of complex malalignment and shortening about the knee. Acute correction of the deformity and gradual lengthening through this osteotomy site has greatly simplified postoperative recovery. This manuscript is a review of the techniques that are currently being used in surgery. Methods: The article is broken into two sections: distal femur osteotomy and tibia osteotomy. Each is addressed separately since they have different personalities. Also included are topics of particular interest that surface in ongoing conferences regarding the ILN. This work is a mix of expert opinion and best practice supported by peer reviewed publications on the topic. Results: Most published series demonstrate excellent results with the ILN. Certain precautions are reiterated including avoiding mechanical failure, need for a percutaneous osteotomy, need for over-reaming, and the need for blocking screws. Discussion: Current controversies will be brought to light and discussed. The reader should find this aspect particularly helpful in navigating this rapidly evolving field. PMID:28322717

  12. The mini-incision mid-vastus approach for total knee arthroplasty.

    PubMed

    Flören, Markus; Reichel, Heiko; Davis, Jack; Laskin, Richard S

    2008-12-01

    Rapid functional recovery and improved range of motion after total knee arthroplasty (TKA) without compromising implant position. Osteoarthritis of the knee requiring TKA. Preoperative flexion < 80 degrees. Flexion contracture > 20 degrees. Body mass index > 40 kg/m(2). Fixed valgus deformity > 15 degrees. Relative: previous open surgery on the knee; systematic steroids (skin fragility); tall muscular males. Straight skin incision over the medial third of the patella from 2 cm proximal to the patella, and then to the level of the tibial tuberosity. Extension of capsular incision 2 cm into the vastus medialis muscle from a point 2 cm proximal to the patella. Deep incision around the medial border of the patella and distally to the level of the tibial tuberosity. The patella is displaced laterally but is not everted in flexion. Knee flexion and extension as necessary to move the soft-tissue surgical window for proximal or distal exposure. Hyperflexion of the knee only for insertion of the tibial component. Knee flexion exercises extension/flexion 0-0-70 degrees using continuous passive motion the day after surgery. Weight bearing to tolerance allowed at 1st day after surgery (walker, two crutches). Thrombosis prophylaxis. 69 patients with 74 TKAs done through the mini-incision mid-vastus approach were available with a minimum 1-year follow-up. A control group was evaluated retrospectively including 52 patients with 57 total knee replacements in which a standard medial parapatellar arthrotomy with patella eversion was used. At all clinical evaluations flexion and the ability to climb stairs were significantly superior in the mid-vastus group indicating a faster recovery and return to functional activities. There were no complications and the radiographic evaluation found no implant or limb malalignment, or signs of early loosening.

  13. Three Point Extension Splint To Treat Flexion Contractures About Limb Synovial Hinge Joints.

    DTIC Science & Technology

    rehabilitating flexion contractures caused by soft tissue injury. More particularly, the invention relates to a three point extension splint to treat flexion contractures about the knee, elbow and/or finger.

  14. Rebound Deformity After Growth Modulation in Patients With Coronal Plane Angular Deformities About the Knee: Who Gets It and How Much?

    PubMed

    Leveille, Lise A; Razi, Ozan; Johnston, Charles E

    2017-05-18

    With observed success and increased popularity of growth modulation techniques, there has been a trend toward use in progressively younger patients. Younger age at growth modulation increases the likelihood of complete deformity correction and need for implant removal before skeletal maturity introducing the risk of rebound deformity. The purpose of this study was to quantify magnitude and identify risk factors for rebound deformity after growth modulation. We performed a retrospective review of all patients undergoing growth modulation with a tension band plate for coronal plane deformity about the knee with subsequent implant removal. Exclusion criteria included completion epiphysiodesis or osteotomy at implant removal, ongoing growth modulation, and <1 year radiographic follow-up without rebound deformity. Mechanical lateral distal femoral angle, mechanical medial proximal tibial angle, hip-knee-ankle angle (HKA), and mechanical axis station were measured before growth modulation, before implant removal, and at final follow-up. In total, 67 limbs in 45 patients met the inclusion criteria. Mean age at growth modulation was 9.8 years (range, 3.4 to 15.4 y) and mean age at implant removal was 11.4 years (range, 5.3 to 16.4 y). Mean change in HKA after implant removal was 6.9 degrees (range, 0 to 23 degrees). In total, 52% of patients had >5 degrees rebound and 30% had >10 degrees rebound in HKA after implant removal. Females below 10 years and males below 12 years at time of growth modulation had greater mean change in HKA after implant removal compared with older patients (8.4 vs. 4.7 degrees, P=0.012). Patients with initial deformity >20 degrees had an increased frequency of rebound >10 degrees compared with patients with less severe initial deformity (78% vs. 22%, P=0.002). Rebound deformity after growth modulation is common. Growth modulation at a young age and large initial deformity increases risk of rebound. However, rebound does not occur in all at risk

  15. Validation of a novel smartphone accelerometer-based knee goniometer.

    PubMed

    Ockendon, Matthew; Gilbert, Robin E

    2012-09-01

    Loss of full knee extension following anterior cruciate ligament surgery has been shown to impair knee function. However, there can be significant difficulties in accurately and reproducibly measuring a fixed flexion of the knee. We studied the interobserver and the intraobserver reliabilities of a novel, smartphone accelerometer-based, knee goniometer and compared it with a long-armed conventional goniometer for the assessment of fixed flexion knee deformity. Five healthy male volunteers (age range 30 to 40 years) were studied. Measurements of knee flexion angle were made with a telescopic-armed goniometer (Lafayette Instrument, Lafayette, IN) and compared with measurements using the smartphone (iPhone 3GS, Apple Inc., Cupertino, CA) knee goniometer using a novel trigonometric technique based on tibial inclination. Bland-Altman analysis of validity and reliability including statistical analysis of correlation by Pearson's method was undertaken. The iPhone goniometer had an interobserver correlation (r) of 0.994 compared with 0.952 for the Lafayette. The intraobserver correlation was r = 0.982 for the iPhone (compared with 0.927). The datasets from the two instruments correlate closely (r = 0.947) are proportional and have mean difference of only -0.4 degrees (SD 3.86 degrees). The Lafayette goniometer had an intraobserver reliability +/- 9.6 degrees. The interobserver reliability was +/- 8.4 degrees. By comparison the iPhone had an interobserver reliability +/- 2.7 degrees and an intraobserver reliability +/- 4.6 degrees. We found the iPhone goniometer to be a reliable tool for the measurement of subtle knee flexion in the clinic setting.

  16. Assessment of Knee Cartilage Stress Distribution and Deformation Using Motion Capture System and Wearable Sensors for Force Ratio Detection.

    PubMed

    Mijailovic, N; Vulovic, R; Milankovic, I; Radakovic, R; Filipovic, N; Peulic, A

    2015-01-01

    Knowledge about the knee cartilage deformation ratio as well as the knee cartilage stress distribution is of particular importance in clinical studies due to the fact that these represent some of the basic indicators of cartilage state and that they also provide information about joint cartilage wear so medical doctors can predict when it is necessary to perform surgery on a patient. In this research, we apply various kinds of sensors such as a system of infrared cameras and reflective markers, three-axis accelerometer, and force plate. The fluorescent marker and accelerometers are placed on the patient's hip, knee, and ankle, respectively. During a normal walk we are recording the space position of markers, acceleration, and ground reaction force by force plate. Measured data are included in the biomechanical model of the knee joint. Geometry for this model is defined from CT images. This model includes the impact of ground reaction forces, contact force between femur and tibia, patient body weight, ligaments, and muscle forces. The boundary conditions are created for the finite element method in order to noninvasively determine the cartilage stress distribution.

  17. Deformation of articular cartilage during static loading of a knee joint--experimental and finite element analysis.

    PubMed

    Halonen, K S; Mononen, M E; Jurvelin, J S; Töyräs, J; Salo, J; Korhonen, R K

    2014-07-18

    Novel conical beam CT-scanners offer high resolution imaging of knee structures with i.a. contrast media, even under weight bearing. With this new technology, we aimed to determine cartilage strains and meniscal movement in a human knee at 0, 1, 5, and 30 min of standing and compare them to the subject-specific 3D finite element (FE) model. The FE model of the volunteer׳s knee, based on the geometry obtained from magnetic resonance images, was created to simulate the creep. The effects of collagen fibril network stiffness, nonfibrillar matrix modulus, permeability and fluid flow boundary conditions on the creep response in cartilage were investigated. In the experiment, 80% of the maximum strain in cartilage developed immediately, after which the cartilage continued to deform slowly until the 30 min time point. Cartilage strains and meniscus movement obtained from the FE model matched adequately with the experimentally measured values. Reducing the fibril network stiffness increased the mean strains substantially, while the creep rate was primarily influenced by an increase in the nonfibrillar matrix modulus. Changing the initial permeability and preventing fluid flow through noncontacting surfaces had a negligible effect on cartilage strains. The present results improve understanding of the mechanisms controlling articular cartilage strains and meniscal movements in a knee joint under physiological static loading. Ultimately a validated model could be used as a noninvasive diagnostic tool to locate cartilage areas at risk for degeneration.

  18. A subdivision-based parametric deformable model for surface extraction and statistical shape modeling of the knee cartilages

    NASA Astrophysics Data System (ADS)

    Fripp, Jurgen; Crozier, Stuart; Warfield, Simon K.; Ourselin, Sébastien

    2006-03-01

    Subdivision surfaces and parameterization are desirable for many algorithms that are commonly used in Medical Image Analysis. However, extracting an accurate surface and parameterization can be difficult for many anatomical objects of interest, due to noisy segmentations and the inherent variability of the object. The thin cartilages of the knee are an example of this, especially after damage is incurred from injuries or conditions like osteoarthritis. As a result, the cartilages can have different topologies or exist in multiple pieces. In this paper we present a topology preserving (genus 0) subdivision-based parametric deformable model that is used to extract the surfaces of the patella and tibial cartilages in the knee. These surfaces have minimal thickness in areas without cartilage. The algorithm inherently incorporates several desirable properties, including: shape based interpolation, sub-division remeshing and parameterization. To illustrate the usefulness of this approach, the surfaces and parameterizations of the patella cartilage are used to generate a 3D statistical shape model.

  19. Comparison of crossed pins and external fixation for correction of angular deformities about the knee in children.

    PubMed

    Davis, C A; Maranji, K; Frederick, N; Dorey, F; Moseley, C F

    1998-01-01

    External fixation was compared to crossed Steinman pins and plaster for fixation after osteotomy about the knee in children. A group of 26 patients treated by external fixation was compared to a control group of 26 patients fixed with crossed Steinman pins and casting. The groups were matched for age, height, and weight. Overall there was a 100% union rate. Preoperative deformity and postoperative correction were similar in the two groups. The time to union was significantly longer, and there were significantly more complications in the external fixator group. There were 16 complications (62%) in the external fixator group and five (19%) in the control group. Complications included pin tract infections, peroneal nerve palsy, and delayed union. External fixation provides certain advantages for fixation after osteotomies about the knee in children but is associated with a variety of complications.

  20. Custom Knee Device for Knee Contractures After Internal Femoral Lengthening.

    PubMed

    Bhave, Anil; Shabtai, Lior; Ong, Peck-Hoon; Standard, Shawn C; Paley, Dror; Herzenberg, John E

    2015-07-01

    The development of knee flexion contractures is among the most common problems and complications associated with lengthening the femur with an internal device or external fixator. Conservative treatment strategies include physical therapy, serial casting, and low-load prolonged stretching with commercially available splinting systems. The authors developed an individually molded, low-cost custom knee device with polyester synthetic conformable casting material to treat knee flexion contractures. The goal of this study was to evaluate the results of treatment with a custom knee device and specialized physical therapy in patients who had knee flexion contracture during femoral lengthening with an intramedullary lengthening femoral nail. This retrospective study included 23 patients (27 limbs) who underwent femoral lengthening with an internal device for the treatment of limb length discrepancy. All patients had a knee flexion contracture raging from 10° to 90° during the lengthening process and were treated with a custom knee device and specialized physical therapy. The average flexion contracture before treatment was 36°. The mean amount of lengthening was 5.4 cm. After an average of 3.8 weeks of use of the custom knee device, only 2 of 27 limbs (7.5%) had not achieved complete resolution of the flexion contracture. The average final extension was 1.4°. Only 7 of 27 limbs (26%) required additional soft tissue release. The custom knee device is an inexpensive and effective method for treating knee flexion contracture after lengthening with an internal device.

  1. Polyethylene damage and deformation on fixed-bearing, non-conforming unicondylar knee replacements corresponding to progressive changes in alignment and fixation.

    PubMed

    Harman, Melinda K; Schmitt, Sabine; Rössing, Sven; Banks, Scott A; Sharf, Hans-Peter; Viceconti, Marco; Hodge, W Andrew

    2010-07-01

    Deviations from nominal alignment of unicondylar knee replacements impact knee biomechanics, including the load and stress distribution at the articular contact surfaces. This study characterizes relationships between the biomechanical environment, distinguished by progressive changes in alignment and fixation, and articular damage and deformation in a consecutive series of retrieved unicondylar knee replacements. Twenty seven fixed-bearing, non-conforming unicondylar knee replacements of one design were retrieved after 2 to 13 years of in vivo function. The in vivo biomechanical environment was characterized by grading component migration measured from full-length radiographs and grading component fixation based on intraoperative manual palpation. Articular damage patterns and linear deformation on the polyethylene inserts were measured using optical photogrammetry and contact point digitization. Articular damage patterns and surface deformation on the explanted polyethylene inserts corresponded to progressive changes in component alignment and fixation. Component migration produced higher deformation rates, whereas loosening contributed to larger damage areas but lower deformation rates. Migration and loosening of the femoral component, but not the tibial component, were factors contributing to large regions of abrasion concentrated on the articular periphery. Classifying component migration and fixation at revision proved useful for distinguishing common biomechanical conditions associated with the varied polyethylene damage patterns and linear deformation for this fixed-bearing, non-conforming design. Pre-clinical evaluations of unicondylar knee replacements that are capable of reproducing variations in clinical alignment and predicting the observed wear mechanisms are necessary to better understand the impact of knee biomechanics and design on unicondylar knee replacement longevity. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  2. The pendulum test as a tool to evaluate passive knee stiffness and viscosity of patients with rheumatoid arthritis

    PubMed Central

    Valle, Maria S; Casabona, Antonino; Sgarlata, Rosaria; Garozzo, Rosaria; Vinci, Maria; Cioni, Matteo

    2006-01-01

    Background The pendulum test of Wartenberg is a technique commonly used to measure passive knee motion with the aim to assess spasticity. We used this test to evaluate changes of the knee angular displacement, passive stiffness and viscosity in rheumatoid arthritis patients. Stiffness and viscosity represent passive resistances to joint motion associated with the structural properties of the joint tissue and of the muscular-tendon complex. Stiffness can be considered an intrinsic property of the tissues to resist deformation, while viscosity is related to cohesive forces between adjacent layers of tissues. Both parameters may influence the joint range of motion affecting angular displacement. Methods Nine women with rheumatoid arthritis were compared with a group of healthy women. With the subject half-lying, the relaxed knee was dropped from near-full extension and the characteristics of the ensuring damped unsustained knee oscillation evaluated. The kinematics of leg oscillations was recorded using ultrasonic markers (Zebris CMS HS 10) and the kinetic data were calculated from kinematic and anthropometric measures. Results Knee stiffness significantly increased (p < 0.001) in patients with respect to the control group, while differences in viscosity were not significant. Moreover, the amplitudes of first knee flexion (the maximal flexion excursion after knee release) and first knee extension (the maximal extension excursion after the first knee flexion) were significantly decreased (p < 0.001). A regression analysis showed that disease severity correlated moderately with stiffness (R2 = 0.68) and first flexion (R2 = 0.78). Using a multivariate regression, we found that increasing stiffness was the main factor for the reduction of flexion and extension motions. Conclusion We showed that the Wartenberg test can be considered a practical tool to measure mechanical changes of knee caused by rheumatoid arthritis. This novel application of Wartenberg test could be

  3. The pendulum test as a tool to evaluate passive knee stiffness and viscosity of patients with rheumatoid arthritis.

    PubMed

    Valle, Maria S; Casabona, Antonino; Sgarlata, Rosaria; Garozzo, Rosaria; Vinci, Maria; Cioni, Matteo

    2006-11-29

    The pendulum test of Wartenberg is a technique commonly used to measure passive knee motion with the aim to assess spasticity. We used this test to evaluate changes of the knee angular displacement, passive stiffness and viscosity in rheumatoid arthritis patients. Stiffness and viscosity represent passive resistances to joint motion associated with the structural properties of the joint tissue and of the muscular-tendon complex. Stiffness can be considered an intrinsic property of the tissues to resist deformation, while viscosity is related to cohesive forces between adjacent layers of tissues. Both parameters may influence the joint range of motion affecting angular displacement. Nine women with rheumatoid arthritis were compared with a group of healthy women. With the subject half-lying, the relaxed knee was dropped from near-full extension and the characteristics of the ensuring damped unsustained knee oscillation evaluated. The kinematics of leg oscillations was recorded using ultrasonic markers (Zebris CMS HS 10) and the kinetic data were calculated from kinematic and anthropometric measures. Knee stiffness significantly increased (p < 0.001) in patients with respect to the control group, while differences in viscosity were not significant. Moreover, the amplitudes of first knee flexion (the maximal flexion excursion after knee release) and first knee extension (the maximal extension excursion after the first knee flexion) were significantly decreased (p < 0.001). A regression analysis showed that disease severity correlated moderately with stiffness (R2 = 0.68) and first flexion (R2 = 0.78). Using a multivariate regression, we found that increasing stiffness was the main factor for the reduction of flexion and extension motions. We showed that the Wartenberg test can be considered a practical tool to measure mechanical changes of knee caused by rheumatoid arthritis. This novel application of Wartenberg test could be useful to follow up the effects of

  4. Non-invasive quantification of lower limb mechanical alignment in flexion

    PubMed Central

    Deakin, Angela; Fogg, Quentin A.; Picard, Frederic

    2014-01-01

    (coefficient ≤2°) was observed until 40° flexion; however, beyond 50° flexion, the repeatability coefficient was >3°. As was the case with precision, agreement between the invasive and non-invasive systems was satisfactory in extension and worsened with flexion. Mean limits of agreement between the invasive and non-invasive system using fabric strapping to assess MFTA were 3° (range: 2.3–3.8°) with no stress applied and 3.9° (range: 2.8–5.2°) with varus and valgus stress. Using rubber strapping, the corresponding values were 4.4° (range: 2.8–8.5°) with no stress applied, 5.5° (range: 3.3–9.0°) with varus stress, and 5.6° (range: 3.3–11.9°) with valgus stress. Discussion Acceptable precision and accuracy may be possible when measuring knee kinematics in early flexion using a non-invasive system; however, we do not believe passive trackers should be mounted with rubber strapping such as was used in this study. Flexing the knee appears to decrease the precision and accuracy of the system. The functions of this new software using image-free navigation technology have many potential clinical applications, including assessment of bony and soft tissue deformity, pre-operative planning, and post-operative evaluation, as well as in further pure research comparing kinematics of the normal and pathological knee. PMID:24856249

  5. Correction of coronal plane deformities around the knee using a tension band plate in children younger than 10 years

    PubMed Central

    Kulkarni, Ruta M; Ilyas Rushnaiwala, Faizaan M; Kulkarni, GS; Negandhi, Rajiv; Kulkarni, Milind G; Kulkarni, Sunil G

    2015-01-01

    Background: Guided growth through temporary hemiepiphysiodesis has gained acceptance as the preferred primary treatment in treating pediatric lower limb deformities as it is minimally invasive with a lesser morbidity than the traditional osteotomy. The tension band plate is the most recent development in implants used for temporary hemiepiphysiodesis. Our aim was to determine its safety and efficacy in correcting coronal plane deformities around the knee in children younger than 10 years. Materials and Methods: A total of 24 children under the age of 10 were operated for coronal plane deformities around the knee with a single extra periosteal tension band plate and two nonlocking screws. All the children had a pathological deformity for which a detailed preoperative work-up was carried out to ascertain the cause of the deformity and rule out physiological ones. The average age at hemiepiphysiodesis was 5 years 3 months (range: 2 years to 9 years 1 month). Results: The plates were inserted for an average of 15.625 months (range: 7 months to 29 months). All the patients showed improvement in the mechanical axis. Two patients showed partial correction. Two cases of screw loosening were observed. In the genu valgum group, the tibiofemoral angle improved from a preoperative mean of 19.89° valgus (range: 10° valgus to 40° valgus) to 5.72° valgus (range: 2° varus to 10° valgus). In patients with genu varum the tibiofemoral angle improved from a mean of 28.27° varus (range: 13° varus to 41° varus) to 1.59° valgus (range: 0-8° valgus). Conclusion: Temporary hemiepiphysiodesis through the application of the tension band plate is an effective method to correct coronal plane deformities around the knee with minimal complications. Its ease and accuracy of insertion has extended the indication of temporary hemiepiphysiodesis to patients younger than 10 years and across a wide variety of diagnosis including pathological physis, which were traditionally out of the

  6. Patterns of knee osteoarthritis in Arabian and American knees.

    PubMed

    Hodge, W Andrew; Harman, Melinda K; Banks, Scott A

    2009-04-01

    This study illustrates differences in the cartilage degeneration in osteoarthritic knees in patients with more frequent hyperflexion activities of daily living compared with Western patients. Proximal tibial articular cartilage wear and cruciate ligament condition were assessed in Saudi Arabian and North American patients with varus osteoarthritis undergoing total knee arthroplasty. In anterior cruciate ligament (ACL) intact knees, there were significant differences in wear location, with a clearly more anterior pattern in Saudi Arabian knees. Complete ACL deficiency occurred in 25% of North American knees but only 14% of Saudi Arabian knees. These ACL-deficient knees showed the most severe cartilage wear in both groups and posterior medial wear patterns. Biomechanical descriptions of knee flexion and axial rotation during kneeling or squatting are consistent with the more pronounced anteromedial and posterolateral cartilage wear patterns observed on the Saudi Arabian knees. These observations provide insight into altered knee mechanics in 2 culturally different populations with different demands on knee flexion.

  7. Postural deformities in congenital nephrotic syndrome.

    PubMed Central

    Morgan, G; Postlethwaite, R J; Lendon, M; Houston, I B; Savage, J M

    1981-01-01

    Six successive cases of congenital nephrotic syndrome are described. Each one showed flexion deformities of the knees and hips, widely open anterior and posterior fontanelles, and wide separation of the skull sutures. These abnormalities were present not only in cases in which the renal histology was of the microcystic Finnish type of congenital nephrotic syndrome, but also in those in which the histological picture was one of the variants associated with congenital nephrotic syndrome. It is suggested that such abnormalities are postural deformities, possibly produced by the large placenta. Images Fig. 1 Fig. 2 PMID:7332344

  8. Determining the Best Treatment for Coronal Angular Deformity of the Knee Joint in Growing Children: A Decision Analysis

    PubMed Central

    Sung, Ki Hyuk; Chung, Chin Youb; Lee, Kyoung Min; Lee, Seung Yeol; Choi, In Ho; Cho, Tae-Joon; Yoo, Won Joon; Park, Moon Seok

    2014-01-01

    This study aimed to determine the best treatment modality for coronal angular deformity of the knee joint in growing children using decision analysis. A decision tree was created to evaluate 3 treatment modalities for coronal angular deformity in growing children: temporary hemiepiphysiodesis using staples, percutaneous screws, or a tension band plate. A decision analysis model was constructed containing the final outcome score, probability of metal failure, and incomplete correction of deformity. The final outcome was defined as health-related quality of life and was used as a utility in the decision tree. The probabilities associated with each case were obtained by literature review, and health-related quality of life was evaluated by a questionnaire completed by 25 pediatric orthopedic experts. Our decision analysis model favored temporary hemiepiphysiodesis using a tension band plate over temporary hemiepiphysiodesis using percutaneous screws or stapling, with utilities of 0.969, 0.957, and 0.962, respectively. One-way sensitivity analysis showed that hemiepiphysiodesis using a tension band plate was better than temporary hemiepiphysiodesis using percutaneous screws, when the overall complication rate of hemiepiphysiodesis using a tension band plate was lower than 15.7%. Two-way sensitivity analysis showed that hemiepiphysiodesis using a tension band plate was more beneficial than temporary hemiepiphysiodesis using percutaneous screws. PMID:25276801

  9. Preliminary analysis of knee stress in Full Extension Landing

    PubMed Central

    Makinejad, Majid Davoodi; Abu Osman, Noor Azuan; Wan Abas, Wan Abu Bakar; Bayat, Mehdi

    2013-01-01

    OBJECTIVE: This study provides an experimental and finite element analysis of knee-joint structure during extended-knee landing based on the extracted impact force, and it numerically identifies the contact pressure, stress distribution and possibility of bone-to-bone contact when a subject lands from a safe height. METHODS: The impact time and loads were measured via inverse dynamic analysis of free landing without knee flexion from three different heights (25, 50 and 75 cm), using five subjects with an average body mass index of 18.8. Three-dimensional data were developed from computed tomography scans and were reprocessed with modeling software before being imported and analyzed by finite element analysis software. The whole leg was considered to be a fixed middle-hinged structure, while impact loads were applied to the femur in an upward direction. RESULTS: Straight landing exerted an enormous amount of pressure on the knee joint as a result of the body's inability to utilize the lower extremity muscles, thereby maximizing the threat of injury when the load exceeds the height-safety threshold. CONCLUSIONS: The researchers conclude that extended-knee landing results in serious deformation of the meniscus and cartilage and increases the risk of bone-to-bone contact and serious knee injury when the load exceeds the threshold safety height. This risk is considerably greater than the risk of injury associated with walking downhill or flexion landing activities. PMID:24141832

  10. Instability following total knee arthroplasty.

    PubMed

    Rodriguez-Merchan, E Carlos

    2011-10-01

    Background Knee prosthesis instability (KPI) is a frequent cause of failure of total knee arthroplasty. Moreover, the degree of constraint required to achieve immediate and long-term stability in total knee arthroplasty (TKA) is frequently debated. Questions This review aims to define the problem, analyze risk factors, and review strategies for prevention and treatment of KPI. Methods A PubMed (MEDLINE) search of the years 2000 to 2010 was performed using two key words: TKA and instability. One hundred and sixty-five initial articles were identified. The most important (17) articles as judged by the author were selected for this review. The main criteria for selection were that the articles addressed and provided solutions to the diagnosis and treatment of KPI. Results Patient-related risk factors predisposing to post-operative instability include deformity requiring a large surgical correction and aggressive ligament release, general or regional neuromuscular pathology, and hip or foot deformities. KPI can be prevented in most cases with appropriate selection of implants and good surgical technique. When ligament instability is anticipated post-operatively, the need for implants with a greater degree of constraint should be anticipated. In patients without significant varus or valgus malalignment and without significant flexion contracture, the posterior cruciate ligament (PCL) can be retained. However, the PCL should be sacrificed when deformity exists particularly in patients with rheumatoid arthritis, previous patellectomy, previous high tibial osteotomy or distal femoral osteotomy, and posttraumatic osteoarthritis with disruption of the PCL. In most cases, KPI requires revision surgery. Successful outcomes can only be obtained if the cause of KPI is identified and addressed. Conclusions Instability following TKA is a common cause of the need for revision. Typically, knees with deformity, rheumatoid arthritis, previous patellectomy or high tibial osteotomy, and

  11. Alterations in walking knee joint stiffness in individuals with knee osteoarthritis and self-reported knee instability.

    PubMed

    Gustafson, Jonathan A; Gorman, Shannon; Fitzgerald, G Kelley; Farrokhi, Shawn

    2016-01-01

    Increased walking knee joint stiffness has been reported in patients with knee osteoarthritis (OA) as a compensatory strategy to improve knee joint stability. However, presence of episodic self-reported knee instability in a large subgroup of patients with knee OA may be a sign of inadequate walking knee joint stiffness. The objective of this work was to evaluate the differences in walking knee joint stiffness in patients with knee OA with and without self-reported instability and examine the relationship between walking knee joint stiffness with quadriceps strength, knee joint laxity, and varus knee malalignment. Overground biomechanical data at a self-selected gait velocity was collected for 35 individuals with knee OA without self-reported instability (stable group) and 17 individuals with knee OA and episodic self-reported instability (unstable group). Knee joint stiffness was calculated during the weight-acceptance phase of gait as the change in the external knee joint moment divided by the change in the knee flexion angle. The unstable group walked with lower knee joint stiffness (p=0.01), mainly due to smaller heel-contact knee flexion angles (p<0.01) and greater knee flexion excursions (p<0.01) compared to their knee stable counterparts. No significant relationships were observed between walking knee joint stiffness and quadriceps strength, knee joint laxity or varus knee malalignment. Reduced walking knee joint stiffness appears to be associated with episodic knee instability and independent of quadriceps muscle weakness, knee joint laxity or varus malalignment. Further investigations of the temporal relationship between self-reported knee joint instability and walking knee joint stiffness are warranted.

  12. Alterations in walking knee joint stiffness in individuals with knee osteoarthritis and self-reported knee instability

    PubMed Central

    Gustafson, Jonathan A.; Gorman, Shannon; Fitzgerald, G. Kelley; Farrokhi, Shawn

    2017-01-01

    Increased walking knee joint stiffness has been reported in patients with knee osteoarthritis (OA) as a compensatory strategy to improve knee joint stability. However, presence of episodic self-reported knee instability in a large subgroup of patients with knee OA may be a sign of inadequate walking knee joint stiffness. The objective of this work was to evaluate the differences in walking knee joint stiffness in patients with knee OA with and without self-reported instability and examine the relationship between walking knee joint stiffness with quadriceps strength, knee joint laxity, and varus knee malalignment. Overground biomechanical data at a self-selected gait velocity was collected for 35 individuals with knee OA without self-reported instability (stable group) and 17 individuals with knee OA and episodic self-reported instability (unstable group). Knee joint stiffness was calculated during the weight-acceptance phase of gait as the change in the external knee joint moment divided by the change in the knee flexion angle. The unstable group walked with lower knee joint stiffness (p=0.01), mainly due to smaller heel-contact knee flexion angles (p<0.01) and greater knee flexion excursions (p<0.01) compared to their knee stable counterparts. No significant relationships were observed between walking knee joint stiffness and quadriceps strength, knee joint laxity or varus knee malalignment. Reduced walking knee joint stiffness appears to be associated with episodic knee instability and independent of quadriceps muscle weakness, knee joint laxity or varus malalignment. Further investigations of the temporal relationship between self-reported knee joint instability and walking knee joint stiffness are warranted. PMID:26481256

  13. [[INFLUENCES OF PREOPERATIVE SEVERE LOWER LIMB DEFORMITY ON PROSTHESIS INSTALLATION AND ALIGNMENT RESTORATION IN TOTAL KNEE ARTHROPLASTY].

    PubMed

    Yu, Baoxi; Fang, Shuying; Fu, Ming; Zhang, Zhiqi; Wu, Peihui; Huang Zhiyu; Sun, Hong

    2016-03-01

    To investigate the effect of preoperative valgus or varus deformity on the prosthesis installation and alignment restoration in total knee arthroplasty (TKA). Between January 2012 and December 2013, 198 patients (245 knees) with osteoarthritis underwent primary TKA, and the clinical data were retrospectively analyzed. There were 23 males and 175 females, with the average age of 67 years (range, 43-90 years). Single knee and double knees were involved in 151 and 47 cases respectively. The disease duration was from 1 month to 30 years (mean, 8.99 years). The anteroposterior X-ray films of whole lower limbs were taken, and the femorotibial angle (FT) was measured before operation and at 1 week after operation; the mechanical femoral angle (MF) and the anatomical tibial angle (AT) at 1 week after operation were measured. The correlation analysis was made for pre- and post-operative FT, MF, and AT. According to the valgus or varus deformity before operation, all patients were divided into 5 groups: ≥ 20 degrees varus (group A), 10-20 degrees varus (group B), ≤ 10 degrees varus (group C), < 10 degrees valgus (group D), and ≥ 10 degrees valgus (group E), and the above indicators were compared between groups. And the rate of the good limb alignment was recorded after operation. The pre- and post-operative FT were (171.53 ± 9.12) and (177.38 ± 3.57)degrees respectively, and postoperative MF and AT were (89.00 ± 2.68) and (88.62 ± 2.16) respectively. Preoperative FT was associated with postoperative FT and MF (r = 0.375, P = 0.000; r = 0.386, P = 0.000), but it was not correlated with AT (r = 0.024, P = 0.710). Postoperative FT was associated with MF and AT (r = 0.707, P = 0.000; r = 0.582, P = 0.000). Postoperative FT was significantly increased when compared with preoperative FT in each group (P < 0.05). There were significant differences in preoperative FT between groups (P < 0.05). There were significant differences in postoperative FT when compared group A

  14. Correction of static axial alignment in children with knee varus or valgus deformities through guided growth: Does it also correct dynamic frontal plane moments during walking?

    PubMed

    Böhm, Harald; Stief, Felix; Sander, Klaus; Hösl, Matthias; Döderlein, Leonhard

    2015-09-01

    Malaligned knees are predisposed to the development and progression of unicompartmental degenerations because of the excessive load placed on one side of the knee. Therefore, guided growth in skeletally immature patients is recommended. Indication for correction of varus/valgus deformities are based on static weight bearing radiographs. However, the dynamic knee abduction moment during walking showed only a weak correlation to malalignment determined by static radiographs. Therefore, the aim of the study was to measure the effects of guided growth on the normalization of frontal plane knee joint moments during walking. 15 legs of 8 patients (11-15 years) with idiopathic axial varus or valgus malalignment were analyzed. 16 typically developed peers served as controls. Instrumented gait analysis and clinical assessment were performed the day before implantation and explantation of eight-plates. Correlation between static mechanical tibiofemoral axis angle (MAA) and dynamic frontal plane knee joint moments and their change by guided growth were performed. The changes in dynamic knee moment in the frontal plane following guided growth showed high and significant correlation to the changes in static MAA (R=0.97, p<0.001). Contrary to the correlation of the changes, there was no correlation between static and dynamic measures in both sessions. In consequence two patients that had a natural knee moment before treatment showed a more pathological one after treatment. In conclusion, the changes in the dynamic load situation during walking can be predicted from the changes in static alignment. If pre-surgical gait analysis reveals a natural load situation, despite a static varus or valgus deformity, the intervention must be critically discussed.

  15. Importance of the different posterolateral knee static stabilizers: biomechanical study

    PubMed Central

    Lasmar, Rodrigo Campos Pace; Marques de Almeida, Adriano; Serbino, José Wilson; da Mota Albuquerque, Roberto Freire; Hernandez, Arnaldo José

    2010-01-01

    PURPOSE The purpose of this study was to evaluate the relative importance of the different static stabilizers of the posterolateral corner of the knee in cadavers. METHODS Tests were performed with the application of a varus and external rotation force to the knee in extension at 30 and 60 degrees of flexion using 10 cadaver knees. The forces were applied initially to an intact knee and then repeated after a selective sectioning of the ligaments into the following: section of the lateral collateral ligament; section of the lateral collateral ligament and the popliteofibular complex; and section of the lateral collateral ligament, the popliteofibular complex and the posterolateral capsule. The parameters studied were the angular deformity and stiffness when the knees were submitted to a 15 Newton-meter varus torque and a 6 Newton-meter external tibial torque. Statistical analysis was performed using the ANOVA (Analysis of Variance) and Tukey’s tests. RESULTS AND CONCLUSION Our findings showed that the lateral collateral ligament was important in varus stability at 0, 30 and 60 degrees. The popliteofibular complex was the most important structure for external rotation stability at all angles of flexion and was also important for varus stability at 30 and 60 degrees. The posterolateral capsule was important for varus stability at 0 and 30 degrees and for external rotation stability in extension. Level of evidence: Level IV (cadaver study). PMID:20454502

  16. Immediate effect of Masai Barefoot Technology shoes on knee joint moments in women with knee osteoarthritis.

    PubMed

    Tateuchi, Hiroshige; Taniguchi, Masashi; Takagi, Yui; Goto, Yusuke; Otsuka, Naoki; Koyama, Yumiko; Kobayashi, Masashi; Ichihashi, Noriaki

    2014-01-01

    Footwear modification can beneficially alter knee loading in patients with knee osteoarthritis. This study evaluated the effect of Masai Barefoot Technology shoes on reductions in external knee moments in patients with knee osteoarthritis. Three-dimensional motion analysis was used to examine the effect of Masai Barefoot Technology versus control shoes on the knee adduction and flexion moments in 17 women (mean age, 63.6 years) with radiographically confirmed knee osteoarthritis. The lateral and anterior trunk lean values, knee flexion and adduction angles, and ground reaction force were also evaluated. The influence of the original walking pattern on the changes in knee moments with Masai Barefoot Technology shoes was evaluated. The knee flexion moment in early stance was significantly reduced while walking with the Masai Barefoot Technology shoes (0.25±0.14Nm/kgm) as compared with walking with control shoes (0.30±0.19 Nm/kgm); whereas the knee adduction moment showed no changes. Masai Barefoot Technology shoes did not increase compensatory lateral and anterior trunk lean. The degree of knee flexion moment in the original walking pattern with control shoes was correlated directly with its reduction when wearing Masai Barefoot Technology shoes by multiple linear regression analysis (adjusted R2=0.44, P<0.01). Masai Barefoot Technology shoes reduced the knee flexion moment during walking without increasing the compensatory trunk lean and may therefore reduce external knee loading in women with knee osteoarthritis.

  17. Three-dimensional bending, torsion and axial compression of the femoropopliteal artery during limb flexion.

    PubMed

    MacTaggart, Jason N; Phillips, Nicholas Y; Lomneth, Carol S; Pipinos, Iraklis I; Bowen, Robert; Baxter, B Timothy; Johanning, Jason; Longo, G Matthew; Desyatova, Anastasia S; Moulton, Michael J; Dzenis, Yuris A; Kamenskiy, Alexey V

    2014-07-18

    High failure rates of femoropopliteal artery reconstruction are commonly attributed to complex 3D arterial deformations that occur with limb movement. The purpose of this study was to develop a method for accurate assessment of these deformations. Custom-made stainless-steel markers were deployed into 5 in situ cadaveric femoropopliteal arteries using fluoroscopy. Thin-section CT images were acquired with each limb in the straight and acutely bent states. Image segmentation and 3D reconstruction allowed comparison of the relative locations of each intra-arterial marker position for determination of the artery's bending, torsion and axial compression. After imaging, each artery was excised for histological analysis using Verhoeff-Van Gieson staining. Femoropopliteal arteries deformed non-uniformly with highly localized deformations in the proximal superficial femoral artery, and between the adductor hiatus and distal popliteal artery. The largest bending (11±3-6±1 mm radius of curvature), twisting (28±9-77±27°/cm) and axial compression (19±10-30±8%) were registered at the adductor hiatus and the below knee popliteal artery. These deformations were 3.7, 19 and 2.5 fold more severe than values currently reported in the literature. Histology demonstrated a distinct sub-adventitial layer of longitudinally oriented elastin fibers with intimal thickening in the segments with the largest deformations. This endovascular intra-arterial marker technique can quantify the non-uniform 3D deformations of the femoropopliteal artery during knee flexion without disturbing surrounding structures. We demonstrate that 3D arterial bending, torsion and compression in the flexed lower limb are highly localized and are substantially more severe than previously reported. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Postoperative femoral component rotation and femoral anteversion after total knee arthroplasty in patients with distal femoral deformity.

    PubMed

    Lim, Hong-Chul; Bae, Ji-Hoon; Kim, Seung-Ju

    2013-08-01

    We asked whether total knee arthroplasty (TKA) in patients with distal femoral deformity (DFD) would change femoral component rotation (FCR) and investigated the correlation between DFD and femoral anteversion (FA). 75 patients were divided into two groups according to the preoperative posterior condylar angle (PCA); group A without DFD (PCA<7°), group B with DFD (PCA>7°). We evaluated the different angles on the CT scan: (1) PCA, (2) angle between the line which is perpendicular to the Whiteside's line and PCL (WLP), and (3) FA. The mean FCRs were external rotation of 0.21°+2.75° in group A and internal rotation of 4.48°+2.51° in group B (P=0.001). The mean preoperative and postoperative FAs were similar in group A but were significantly different in group B (P=0.035). DFD resulted in excessive internal rotation of the femoral component. There was a secondary decrease in FA in patients with DFD. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. No difference between unicompartmental versus total knee arthroplasty for the management of medial osteoarthtritis of the knee in the same patient: a systematic review and pooling data analysis.

    PubMed

    Longo, Umile Giuseppe; Loppini, Mattia; Trovato, Ugo; Rizzello, Giacomo; Maffulli, Nicola; Denaro, Vincenzo

    2015-06-01

    One-third of patients with knee osteoarthritis (OA) has involvement of only one compartment, especially the medial one. We performed a comprehensive search of studies comparing unicompartmental knee arthoplasty (UKA) and total knee arthroplasty (TKA) in the same patient on PubMed, OVID/Medline, Cochrane, CINAHL, Google scholar and Embase databases. UKA is indicated in knee with medial OA, no flexion deformity, no joint instability and no varus deformity. Although high tibial osteotomy, UKA and TKA have been proposed to address medial OA of the knee, the best management is still controversial. Studies investigating surgical management of medial OA of the knee are increasingly frequent. Large, multicentre, powered, randomized trials comparing UKA and TKA are needed to identify the best management for medial OA of the knee. Moreover, new score systems for satisfaction of the patient should be formulated. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  20. Open Knee: Open Source Modeling and Simulation in Knee Biomechanics.

    PubMed

    Erdemir, Ahmet

    2016-02-01

    Virtual representations of the knee joint can provide clinicians, scientists, and engineers the tools to explore mechanical functions of the knee and its tissue structures in health and disease. Modeling and simulation approaches such as finite element analysis also provide the possibility to understand the influence of surgical procedures and implants on joint stresses and tissue deformations. A large number of knee joint models are described in the biomechanics literature. However, freely accessible, customizable, and easy-to-use models are scarce. Availability of such models can accelerate clinical translation of simulations, where labor-intensive reproduction of model development steps can be avoided. Interested parties can immediately utilize readily available models for scientific discovery and clinical care. Motivated by this gap, this study aims to describe an open source and freely available finite element representation of the tibiofemoral joint, namely Open Knee, which includes the detailed anatomical representation of the joint's major tissue structures and their nonlinear mechanical properties and interactions. Three use cases illustrate customization potential of the model, its predictive capacity, and its scientific and clinical utility: prediction of joint movements during passive flexion, examining the role of meniscectomy on contact mechanics and joint movements, and understanding anterior cruciate ligament mechanics. A summary of scientific and clinically directed studies conducted by other investigators are also provided. The utilization of this open source model by groups other than its developers emphasizes the premise of model sharing as an accelerator of simulation-based medicine. Finally, the imminent need to develop next-generation knee models is noted. These are anticipated to incorporate individualized anatomy and tissue properties supported by specimen-specific joint mechanics data for evaluation, all acquired in vitro from varying age

  1. The medial gastrocnemius muscle attenuates force fluctuations during plantar flexion.

    PubMed

    Shinohara, Minoru; Yoshitake, Yasuhide; Kouzaki, Motoki; Fukunaga, Tetsuo

    2006-02-01

    Force fluctuations during steady contractions of multiple agonist muscles may be influenced by the relative contribution of force by each muscle. The purpose of the study was to compare force fluctuations during steady contractions performed with the plantar flexor muscles in different knee positions. Nine men (25.8+/-5.1 years) performed steady contractions of the plantar flexor muscles in the knee-flexed and knee-extended (greater involvement of the gastrocnemii muscles) positions. The maximal voluntary contraction (MVC) force was 32% greater in the knee-extended position compared with the knee-flexed position. The target forces were 2.5-10% MVC force in the respective position. The amplitude of electromyogram in the medial gastrocnemius muscle was greater in the knee-extended position (10.50+/-9.80%) compared with the knee-flexed position (1.26+/-1.15%, P<0.01). The amplitude of electromyogram in the soleus muscle was not influenced by the knee position. The amplitude of electromyogram in the lateral gastrocnemius and tibialis anterior muscles was marginal and unaltered with knee position. At the same force (in Newtons), the standard deviation of force was lower in the knee-extended position compared with the knee-flexed position. These results indicate that force fluctuations during plantar flexion are attenuated with greater involvement of the medial gastrocnemius muscle.

  2. Femoral component rotation in total knee arthroplasty: an MRI-based evaluation of our options.

    PubMed

    Patel, Anay R; Talati, Rushi K; Yaffe, Mark A; McCoy, Brett W; Stulberg, S David

    2014-08-01

    Proper femoral component rotation is crucial in successful total knee arthroplasty. Rotation using anatomic landmarks has traditionally referenced the transepicondylar axis (TEA), Whiteside's Line (WSL), or posterior condylar axis (PCA). TEA is thought to best approximate the flexion-axis of the knee, however WSL or PCA are common surrogates in the operating room. This study evaluated 560 knees using MRI-based planning software to assess the relationship of WSL and PCA to the TEA and determine if the relationships were influenced by pre-operative coronal deformity. Results showed the WSL-TEA relationship has more variability than PCA-TEA and that the PCA is more internally rotated in females and valgus knees. Axis options and historical assumptions about axis relationships may need to be reassessed as imaging technology advances. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Arthrofibrosis after TKA - Influence factors on the absolute flexion and gain in flexion after manipulation under anaesthesia.

    PubMed

    Ipach, Ingmar; Mittag, Falk; Lahrmann, Julia; Kunze, Beate; Kluba, Torsten

    2011-08-12

    Stiffness with decreased range of motion (ROM) has been described as a frustrating complication after TKA. If all methods of physiotherapeutic treatment have been exhausted trying to develop ROM, manipulation under anaesthesia (MUA) can be discussed. The aim of the present study was to show the effect of MUA and to determine the influence of BMI, number of previous surgical procedures, pre-MUA ROM and timing of MUA for the results after MUA in regard to absolute flexion and gain in flexion. 858 patients underwent TKA at our institution between 2004 and 2009. 39 of these patients underwent MUA because of postoperative knee stiffness. The data were retrospective analysed for the influence of BMI, pre-MUA flexion (/≤ 30 days after TKA) and number of previous surgery on the results after MUA (absolute Flexion/gain in flexion). The prevalence for stiffness after TKA was 4.54%. There was a statistically significant improvement in flexion not only directly after MUA but also 6 weeks after MUA. Patients with two or more previous operations before TKA showed statistically significant worse results six weeks after MUA in absolute flexion and gain in flexion(p = 0.039) than patients with one or two previous operations. No statistical significance in absolute flexion (p = 0.655) and gain in flexion (p = 0.328) after MUA between "early" and "late" was detected. The stiffer knees with a flexion below 70° showed significantly worse results (p = 0.044) in absolute flexion six weeks after MUA, but they also had statistical statistically better results with regard to gain in flexion (p ≤ 0.001). MUA is a good instrument for improving ROM after TKA. The time between TKA and MUA seems less important, so different types of physiotherapeutic treatment could be tried before the procedure is started. MUA in patients with many previous operations and a flexion of less than 70° before MUA is not as effective as in other patients, but they also benefit from

  4. Arthrofibrosis after TKA - Influence factors on the absolute flexion and gain in flexion after manipulation under anaesthesia

    PubMed Central

    2011-01-01

    Background Stiffness with decreased range of motion (ROM) has been described as a frustrating complication after TKA. If all methods of physiotherapeutic treatment have been exhausted trying to develop ROM, manipulation under anaesthesia (MUA) can be discussed. The aim of the present study was to show the effect of MUA and to determine the influence of BMI, number of previous surgical procedures, pre-MUA ROM and timing of MUA for the results after MUA in regard to absolute flexion and gain in flexion. Methods 858 patients underwent TKA at our institution between 2004 and 2009. 39 of these patients underwent MUA because of postoperative knee stiffness. The data were retrospective analysed for the influence of BMI, pre-MUA flexion (/≤ 30 days after TKA) and number of previous surgery on the results after MUA (absolute Flexion/gain in flexion). Results The prevalence for stiffness after TKA was 4.54%. There was a statistically significant improvement in flexion not only directly after MUA but also 6 weeks after MUA. Patients with two or more previous operations before TKA showed statistically significant worse results six weeks after MUA in absolute flexion and gain in flexion (p = 0.039) than patients with one or two previous operations. No statistical significance in absolute flexion (p = 0.655) and gain in flexion (p = 0.328) after MUA between "early" and "late" was detected. The stiffer knees with a flexion below 70° showed significantly worse results (p = 0.044) in absolute flexion six weeks after MUA, but they also had statistical statistically better results with regard to gain in flexion (p ≤ 0.001). Conclusion MUA is a good instrument for improving ROM after TKA. The time between TKA and MUA seems less important, so different types of physiotherapeutic treatment could be tried before the procedure is started. MUA in patients with many previous operations and a flexion of less than 70° before MUA is not as effective as in

  5. Computer-assisted surgery as indication of choice: total knee arthroplasty in case of retained hardware or extra-articular deformity.

    PubMed

    Tigani, Domenico; Masetti, Gilberto; Sabbioni, Giacomo; Ben Ayad, Rida; Filanti, Mattia; Fosco, Matteo

    2012-07-01

    The use of traditional cutting guides during knee arthroplasty in some cases could be extremely difficult, if not impossible, because of angular deformities, IM sclerosis, long-stemmed hip implants, or hardware within the femoral canal that cannot be removed. In these difficult cases navigation-assisted knee arthroplasty should be considered as an effective and appealing option. We present 14 cases in which ideal mechanical and prosthetic alignment was achieved with different image-free, computer-assisted navigation systems, because of an extra-articular deformity (group A, nine patients) or because of a retained implant or hardware (group B, five patients). After a mean follow-up of 28 months (range 12-53 months), the average knee score increased overall from a mean of 33 points (range 12-63) to 78 points (range 63-90). The average functional score improved from a mean of 32 points (range 10-65) to 72 points (range 40-90). The postoperative mechanical axis ranged between 3° of varus and 3° of valgus. There was an implant revision in one patient who had a traumatic rupture of medial collateral ligament, which occurred 27 months after the index procedure. Based on our results we think that the navigation-assisted technique provides an alternative approach to the traditional instrumentation for treating these difficult patients in an effective and less invasive manner.

  6. Can an anterior quadriceps release improve range of motion in the stiff arthritic knee?

    PubMed

    Tarabichi, Samih; Tarabichi, Yasir

    2010-06-01

    We hypothesize that tethering adhesions of the quadriceps muscle are the major pathological structures responsible for a limited range of motion in the stiff arthritic knee. Forty-two modified quadriceps muscle releases were performed on 24 patients with advanced osteoarthritis scheduled for total knee arthroplasty. The ranges of motion were documented intraoperatively both before and immediately after the release. Passive flexion improved significantly in all patients (mean, 32.4 degrees of improvement, P < .001) following a modified quadriceps release, despite any presence of osteophytes or severe deformities. These results strongly implicate adhesions of the quadriceps muscle to the underlying femur, which prevent the distal excursion of the quadriceps tendon, as the restrictive pathology preventing deep flexion in patients with osteoarthritis.

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

    PubMed Central

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

    2012-01-01

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

  8. Knee rotation associated with dynamic knee valgus and toe direction.

    PubMed

    Ishida, Tomoya; Yamanaka, Masanori; Takeda, Naoki; Aoki, Yoshimitsu

    2014-03-01

    Dynamic knee valgus contributes to injuries of the anterior cruciate ligament (ACL). However, it is unclear how the knee rotates during dynamic knee valgus. Knee rotation significantly affects ACL strain. To understand knee rotation during dynamic knee valgus should help the clinician evaluate dynamic alignment. The purpose of this study was to determine how the knee rotates during dynamic knee valgus and whether the knee rotation is affected by toe direction (foot rotation). Sixteen females performed dynamic knee valgus in three toe directions (neutral, toe-out, and toe-in) while maintaining the knee flexion angle at 30°. The knee rotation angle was evaluated using a 7-camera motion analysis system. Knee rotation was compared between the start position and the dynamic knee valgus position, as well as among the three toe directions, using repeated measures ANOVA models. The knee significantly rotated externally in the dynamic knee valgus position compared with the start position in two toe directions (neutral and toe-out). A similar tendency was observed with the toe-in condition. Toe direction significantly affected the knee rotation angle. For toe-out and toe-in conditions, external and internal shifts of knee rotation compared with neutral were observed. The knee rotates externally during dynamic knee valgus, and the knee rotation is affected by toe direction. Because of knee abduction and external rotation, the ACL may impinge on the femoral condyle in the case of dynamic valgus, especially in the toe-out position. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Gap balancing in total knee arthroplasty.

    PubMed

    Bottros, John; Gad, Bishoy; Krebs, Viktor; Barsoum, Wael K

    2006-06-01

    It is well known that the success of total knee arthroplasty is collectively dependent on the proper recreation of the joint line, appropriate soft tissue balancing, and respectful management of the extensor mechanism. One of the most decisive factors within the surgeon's control is the reestablishment of proper knee kinematics through both medial-lateral and flexion-extension ligamentous balancing. This can be accomplished only by a comprehensive intraoperative evaluation in full flexion, mid flexion, and full extension to minimize potential gap mismatches. Most of the discussion will focus on this aspect of soft tissue balancing, but this does not undermine the importance of the other aforementioned principles of successful knee arthroplasty.

  10. Intraoperative passive kinematics of osteoarthritic knees before and after total knee arthroplasty.

    PubMed

    Siston, Robert A; Giori, Nicholas J; Goodman, Stuart B; Delp, Scott L

    2006-08-01

    Total knee arthroplasty is a successful procedure to treat pain and functional disability due to osteoarthritis. However, precisely how a total knee arthroplasty changes the kinematics of an osteoarthritic knee is unknown. We used a surgical navigation system to measure normal passive kinematics from 7 embalmed cadaver lower extremities and in vivo intraoperative passive kinematics on 17 patients undergoing primary total knee arthroplasty to address two questions: How do the kinematics of knees with advanced osteoarthritis differ from normal knees?; and, Does posterior substituting total knee arthroplasty restore kinematics towards normal? Osteoarthritic knees displayed a decreased screw-home motion and abnormal varus/valgus rotations between 10 degrees and 90 degrees of knee flexion when compared to normal knees. The anterior-posterior motion of the femur in osteoarthritic knees was not different than in normal knees. Following total knee arthroplasty, we found abnormal varus/valgus rotations in early flexion, a reduced screw-home motion when compared to the osteoarthritic knees, and an abnormal anterior translation of the femur during the first 60 degrees of flexion. Posterior substituting total knee arthroplasty does not appear to restore normal passive varus/valgus rotations or the screw motion and introduces an abnormal anterior translation of the femur during intraoperative evaluation.

  11. In vivo knee kinematics in patients with bilateral total knee arthroplasty of 2 designs.

    PubMed

    Okamoto, Nobukazu; Breslauer, Leigh; Hedley, Anthony K; Mizuta, Hiroshi; Banks, Scott A

    2011-09-01

    Many younger and highly active patients desire to achieve high flexion after total knee arthroplasty. This study's purpose was to determine if a contemporary total knee arthroplasty design improved functional knee flexion compared with a traditional total knee arthroplasty in patients living a Western lifestyle. Ten patients with bilateral total knee arthroplasty of 2 types were studied during weight-bearing lunge, kneeling, and stair activities using fluoroscopic imaging. There were no differences in maximum knee flexion during lunging or kneeling. Statistically significant differences in tibial rotation and condylar translation were observed during the 3 activities. Although several joint kinematic differences were observed, no important functional differences were observed in clinically excellent, high performing subjects with bilateral total knee arthroplasty of 2 types.

  12. Influence of hip-flexion angle on hamstrings isokinetic activity in sprinters.

    PubMed

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

    2012-01-01

    Hamstrings strains are common and debilitating injuries in many sports. Most hamstrings exercises are performed at an inadequately low hip-flexion angle because this angle surpasses 70° at the end of the sprinting leg's swing phase, when most injuries occur. To evaluate the influence of various hip-flexion angles on peak torques of knee flexors in isometric, concentric, and eccentric contractions and on the hamstrings-to-quadriceps ratio. Descriptive laboratory study. Research laboratory. Ten national-level sprinters (5 men, 5 women; age = 21.2 ± 3.6 years, height = 175 ± 6 cm, mass = 63.8 ± 9.9 kg). For each hip position (0°, 30°, 60°, and 90° of flexion), participants used the right leg to perform (1) 5 seconds of maximal isometric hamstrings contraction at 45° of knee flexion, (2) 5 maximal concentric knee flexion-extensions at 60° per second, (3) 5 maximal eccentric knee flexion-extensions at 60° per second, and (4) 5 maximal eccentric knee flexionextensions at 150° per second. Hamstrings and quadriceps peak torque, hamstrings-to-quadriceps ratio, lateral and medial hamstrings root mean square. We found no difference in quadriceps peak torque for any condition across all hip-flexion angles, whereas hamstrings peak torque was lower at 0° of hip flexion than at any other angle (P < .001) and greater at 90° of hip flexion than at 30° and 60° (P < .05), especially in eccentric conditions. As hip flexion increased, the hamstrings-to-quadriceps ratio increased. No difference in lateral or medial hamstrings root mean square was found for any condition across all hip-flexion angles (P > .05). Hip-flexion angle influenced hamstrings peak torque in all muscular contraction types; as hip flexion increased, hamstrings peak torque increased. Researchers should investigate further whether an eccentric resistance training program at sprint-specific hip-flexion angles (70° to 80°) could help prevent hamstrings injuries in sprinters. Moreover, hamstrings

  13. Nonuniform Weakness in the Paretic Knee and Compensatory Strength Gains in the Nonparetic Knee Occurs after Stroke

    PubMed Central

    Lomaglio, Melanie J.; Eng, Janice J.

    2015-01-01

    Background This study was designed to quantify torque production at different joint angles in the paretic and non-paretic knee joints of individuals with stroke. Methods Extension and flexion torques were measured at 6 angles of the knee joint and normalized to peak torque in 19 subjects with stroke and 19 controls. Results Paretic knee extension torque was lower than controls when the knee was positioned near extension. In contrast, nonparetic knee extension and flexion torques were higher than controls when the knee was positioned near full flexion. Conclusions The paretic knee extensors demonstrated exaggerated weakness at short muscle lengths and the nonparetic knee extensors and flexors demonstrated selective strength gains. Clinicians should therefore consider paretic knee extensor strengthening near full extension and promote symmetrical use of the legs to prevent compensatory overuse of the non-paretic leg. PMID:18946213

  14. Knee joint kinematics, fixation and function related to joint area design in total knee arthroplasty.

    PubMed

    Uvehammer, J

    2001-02-01

    The aim was to study the influence of different designs of the joint area on tibial component fixation, kinematics and clinical outcome after a cemented total knee arthroplasty (TKA). The HSS score and a special questionnaire were used at the clinical examination. Conventional radiography was done to record the positioning of the implants and development of radiolucencies. The migration and inducible displacement were evaluated using radiostereometry (RSA). The kinematics of the knee during active extension was studied using dynamic RSA. In randomised and prospective studies 87 knees in 83 patients (28 male, 55 female, age 69, range 50-83) received an AMK (DePuy, Johnson & Johnson) TKA. The patients were divided into two groups. In group 1 the patients had varus/valgus deformities of < or = 5 degrees and the PCL was retained. The PCL was resected in group 2 where the patients had deformities exceeding 5 degrees and/or fixed flexion deformities of more than 10 degrees. In group 1 a flat (F, n = 20) or a concave (C, n = 20) design was implanted (study 3). In group 2 (study 4) the patients received a concave (n = 25) or a posterior-stabilised (PS, n = 22) tibial plateau. The migration of the tibial component, positioning of the prosthesis, development of radiolucencies and the clinical outcome was evaluated after 1 and 2 years. Twenty-two patients (11 F, 11 C) in group 1 (study 1) and 22 knees in 20 patients in group 2 (study 2, 11 C, 11 PS) were examined 1 year post-operatively to evaluate the kinematics of the knee. Eleven normals served as controls. During active extension of the knee the inducible displacements of the tibial component were recorded in 16 knees (15 patients). Based on successful RSA examinations 5 knees (4 F, 1 C) from group 1 and 11 knees (5 C, 6 PS) from group 2 were selected (study 5). Abnormal kinematics and especially increased AP translations compared to normals (p < 0.0005) were recorded in all designs. The concave design showed the widest

  15. Effect of the knee position during wound closure after total knee arthroplasty on early knee function recovery

    PubMed Central

    2014-01-01

    Objective This study investigated the effect of the knee position during wound closure on early knee function recovery after total knee arthroplasty (TKA). Methods This study included 80 primary total knee arthroplasties due to osteoarthritis. The patients were randomized according to the type of wound closure: extension group for full extension and flexion group for 90° flexion. The incision of articular capsule was marked for precise wound alignment. In the flexion group, the knee was kept in high flexion for 1 to 2 min after wound closure. The two groups were treated with the same postoperative rehabilitation exercises. The range of motion (ROM), visual analogue scale (VAS) score of anterior knee pain, Knee Society Score (KSS) and postoperative complications were assessed at 6 weeks, 3 months and 6 months, postoperatively. Results At 6 weeks and 3 months postoperatively, the ROM in flexion group was 98.95 ± 10.33° and 110.05 ± 4.93° respectively, with 87.62 ± 8.92° and 95.62 ± 6.51° in extension group, respectively; The VAS score of anterior knee pain in flexion group was 2.02 ± 1.38 and 2.21 ± 0.87, respectively, with 2.57 ± 1.07 and 2.87 ± 0.83 in extension group, respectively. The ROM and VAS pain score of the two groups were significantly different at these two time points, with no significant difference at 6 months postoperatively. The two groups were not significantly different in KSS, and no apparent complication was observed at three time points. Conclusion Marking the articular capsule incision, wound closure in flexion and high flexion after wound closure can effectively decrease anterior knee pain after TKA and promote the early recovery of ROM. PMID:25149657

  16. Manipulation under anesthesia for post traumatic stiff knee-pearls, pitfalls and risk factors for failure.

    PubMed

    Saini, Pramod; Trikha, Vivek

    2016-10-01

    Stiffness is common following fractures around knee. Manipulation under anesthesia (MUA) is the initial noninvasive procedure usually performed for such patients. Though MUA has been extensively evaluated for knee arthroplasty, there is paucity of literature regarding its benefits in trauma cases. The purpose of this study was to define the role of manipulation in post traumatic stiff knees. Hospital inpatient and outpatient records from January 2010 to June 2014 were retrospectively reviewed to identify patients undergoing MUA at our institution. Patients with more than one year follow up and adequate data were included. Clinical and radiographic parameters were analyzed to assess outcomes, complications, effect of timing on flexion gain as well as identify risk factors associated with failure. Out of 45 patients undergoing manipulation, 41 patients with 48 knees (34 unilateral and 7 bilateral) met inclusion criteria. Thirty six manipulations were successful while 3 were abandoned due to tight tissues and 9 developed complications.Successful MUA resulted in immediate gain of 62.36° of flexion which decreased to 49.86° at 1year. There was statistically significant loss of flexion of 12.5° over a year (p value 0.0013). Arc of motion improved from 48.5° to 106.1° at 1year (p value <0.0001). Significant improvement was also seen in extension and fixed flexion deformity (p value <0.0001). No significant difference could be detected between early (<3 months) and late (>3 months) groups with respect to outcomes (p value 0.883)or complications (p value 0.3193). Failed group had significantly lower pre MUA flexion and pre MUA range of motion (p value 0.003). Univariate analysis showed that extensor mechanism ruptures during injury (p value <0.0001) and knees with Flexion <40° (p value 0.0022) or ROM<30° (p value 0.0002) were significantly associated with failures. MUA is a suitable non invasive treatment option for post traumatic stiffness. There is no effect of

  17. Creep and fatigue development in the low back in static flexion.

    PubMed

    Shin, Gwanseob; D'Souza, Clive; Liu, Yu-Hsun

    2009-08-01

    In vivo measurements of low back flexion posture and muscle activity before, during, and after static flexion. To identify the occurrence of creep and muscle fatigue development in the low back during static upper body deep flexion that resembled an above ground work posture. Static lumbar flexion has been related to the development of low back disorders, and its injury mechanism has been focused on the changes in passive spinal tissues. Potential influences of muscle fatigue of extensor muscles have not been explored. A total of 20 asymptomatic subjects performed submaximal isometric trunk extension exertions and an isokinetic trunk flexion before and immediately after 5-minute static flexion while the trunk sagittal flexion angle and the myoelectric activities (electromyography [EMG]) of back extensor muscles were recorded simultaneously. Changes in the flexion-relaxation onset angle, maximum flexion angle, muscle activity level, and the median power frequency of EMG associated with the static flexion were evaluated. Flexion-relaxation onset angle in isokinetic flexion and EMG amplitude of isometric extension were significantly greater after static flexion, indicating creep of spinal tissues in static flexion. Median power frequency of lumbar erector spinae EMG during isometric extension was significantly lower after static flexion, suggesting the development of muscle fatigue. Consistent but low level of EMG was observed together with sporadic muscle spasms during the static flexion period. Fatigue of low back extensor muscles may occur in static flexion due to prolonged passive stretching of the muscles. Low back extensor muscles are required to generate more active forces in weight holding or lifting after static flexion to compensate for the reduced contribution of creep deformed passive tissues in maintaining spinal stability and the posture. The degraded force generating capacity of the fatigued muscles can be a significant risk factor for low back pain.

  18. Validating Dual Fluoroscopy System Capabilities for Determining In-Vivo Knee Joint Soft Tissue Deformation: A Strategy for Registration Error Management.

    PubMed

    Sharma, Gulshan B; Kuntze, Gregor; Kukulski, Diane; Ronsky, Janet L

    2015-07-16

    Knee osteoarthritis (OA) causes structural and mechanical changes within tibiofemoral (TF) cartilage affecting tissue load deformation behavior. Quantifying in-vivo TF soft tissue deformations in healthy and early OA may provide a novel biomechanical marker, sensitive to alterations occurring prior to radiographic change. Dual Fluoroscopy (DF) allows accurate in-vivo TF soft tissue deformation assessment but requires validation. In-vivo healthy and early OA TF cartilage deforms 0.3-1.2mm during static standing full body-weight loading. Our aim was to establish minimum detectable displacement (MDD) for femoral translation in a DF system using a marker-based and markerless approach with variable image intensifier magnifications. An instrumented frame allowed controlled femur specimen translations. Bone positions were reconstructed from DF data using centroids of affixed steel beads (marker-based) and 2D-3D bone feature registration (markerless). Statistical analyses included independent samples t-tests and reliability analysis. Markerless measurements by three trained operators had large variations making it prudent to have an appropriate error management strategy when performing 2D-3D registration. Marker-based MDD improved with image resolution and was 0.05 mm at 3.2 LP/mm (LP: line pairs). Markerless MDD at 3.2 LP/mm was 0.08 mm. Average femur and tibia 2D-3D registrations yielded excellent reliability (84.4%). Therefore, DF images acquired at resolution greater than 3.2 LP/mm would be capable for determining accurate and reliable in-vivo healthy and early OA TF soft tissue deformation. This study provides a registration error management strategy for in-vivo TF soft tissue deformation assessment that could be applied for future clinical applications to establish non-invasive biomechanical markers for early OA diagnosis.

  19. Does the Q - H index show a stronger relationship than the H:Q ratio in regard to knee pain during daily activities in patients with knee osteoarthritis?

    PubMed

    Fujita, Remi; Matsui, Yasumoto; Harada, Atsushi; Takemura, Marie; Kondo, Izumi; Nemoto, Tetsuya; Sakai, Tadahiro; Hiraiwa, Hideki; Ota, Susumu

    2016-12-01

    [Purpose] The purpose of this study was to elucidate the relationship between knee muscle strength and knee pain in activities of daily living, based on consideration of the difference between extension and flexion strength (Q - H) and the hamstring:quadriceps (H:Q) ratio in patients with knee osteoarthritis. [Subjects and Methods] The participants were 78 females with knee osteoarthritis, and a total of 133 knees that had not been treated surgically were the targets of this research. The legs were divided according to dominance. Isometric knee extension and flexion muscle strength and knee pain during activities of daily living were measured. The H:Q ratio (flexion/extension muscle strength) and the difference between extension and flexion strength, (extension muscle strength/weight) minus (flexion muscle strength/weight), that is, Q - H, were calculated. The correlation between these indices and the knee pain score during activities of daily living was investigated. [Results] Greater knee pain during activities of daily living was related to lower knee extension muscle strength and Q - H in both the dominant and nondominant legs. Knee flexion muscle strength and the H:Q ratio were not significantly correlated with knee pain during any activities of daily living. [Conclusion] Knee extension muscle strength and Q - H were found to be significantly correlated with knee pain during activities of daily living, whereas the H:Q ratio was not.

  20. Arthrofibrosis following total knee replacement; does therapeutic warfarin make a difference?

    PubMed

    Walton, N P; Jahromi, I; Dobson, P J; Angel, K R; Lewis, P L; Campbell, D G

    2005-04-01

    Arthrofibrosis following total knee replacement (TKR) is a relatively common complication which results in a reduction in knee range of movement and patient dissatisfaction. A retrospective study examined the relationship between anticoagulation with therapeutic warfarin and rates of arthrofibrosis following TKR. Arthrofibrosis was defined as less than 80 degrees of knee flexion 6-8 weeks post-TKR. Patients were warfarinised if they had a history of thrombophilic tendencies or medical conditions necessitating anti-coagulation, rather than as routine thromboprophylaxis. All other patients received thromboprophylaxis using low molecular weight heparin. A total of 728 patients underwent 874 primary TKR between 1993 and 2002 in one centre, performed by four surgeons. Mean age was 68 years (range 48-89 years) and there were 483 female and 391 male knees. Eighty cases were warfarinised post-operatively (53 female, 27 male). Overall, 83 of 874 TKRs (9%) had arthrofibrosis (57 female, 26 male) requiring manipulation under anaesthetic (MUA). In the warfarinised group, 21 knees (26%) had an MUA (15 female, 6 male). This compared to 62 cases (8%) requiring MUA in the non-warfarinised group (42 female, 20 male). There was a statistically significant difference on Fisher's exact testing (P<0.0001) between groups. Following MUA, knee flexion improved in 95% cases to a minimum 95 degrees but 8 cases had a fixed flexion deformity of 5-10 degrees . In conclusion, therapeutic warfarinisation post-TKR leads to a statistically greater chance of the patient developing arthrofibrosis compared to prophylactic low molecular weight heparin and that patients should be counseled appropriately.

  1. Comparison of knee gait kinematics of workers exposed to knee straining posture to those of non-knee straining workers.

    PubMed

    Gaudreault, Nathaly; Hagemeister, Nicola; Poitras, Stéphane; de Guise, Jacques A

    2013-06-01

    Workers exposed to knee straining postures, such as kneeling and squatting, may present modifications in knee gait kinematics that can make them vulnerable to osteoarthritis. In this study, knee kinematics of workers exposed to occupational knee straining postures (KS workers) were compared to those of non-knee straining (non-KS) workers. Eighteen KS workers and 20 non-KS workers participated in the study. Three-dimensional gait kinematic data were recorded at the knee using an electromagnetic motion tracking system. The following parameters were extracted from flexion/extension, adduction/abduction and internal/external rotation angle data and used for group comparisons: knee angle at initial foot contact, peak angles, minimal angles and angle range during the entire gait cycle. Group comparisons were performed with Student t-tests. In the sagittal plane, KS workers had a greater knee flexion angle at initial foot contact, a lower peak knee flexion angle during the swing phase and a lower angle range than non-KS workers (p<0.05). In the frontal plane, all parameters indicated that KS workers had their knees more adducted than non-KS workers. External/internal rotation range was greater for KS workers. This study provides new knowledge on work related to KS postures and knee kinematics. The results support the concept that KS workers might exhibit knee kinematics that are different from those of non-KS workers.

  2. Evolution of knee kinematics three months after total knee replacement.

    PubMed

    Alice, Bonnefoy-Mazure; Stéphane, Armand; Yoshisama, Sagawa Junior; Pierre, Hoffmeyer; Domizio, Suvà; Hermes, Miozzari; Katia, Turcot

    2015-02-01

    In patients with debilitating knee osteoarthritis, total knee replacement is the most common surgical procedure. Numerous studies have demonstrated that knee kinematics one year after total knee replacement are still altered compared to the healthy joint. However, little is known regarding impairments and functional limitations of patients several months after total knee replacement. The aim of this study was to describe the evolution of the knee gait kinematic in patients with knee osteoarthritis before and three months after a total knee replacement. Ninety patients who were to undergo total knee replacement were included in this study. Twenty-three subjects were recruited as the control group. Three-dimensional gait analysis was performed before and three months after surgery. The spatio-temporal parameters and three-dimensional knee kinematics for the operated limb were evaluated during a comfortable gait and compared between groups (the before and after surgery groups and the control group). Three months after surgery, patients always walk with a slower gait velocity and lower knee flexion-extension movements compared to the control group. However, a degree of progress was observed in term of the stride and step length, gait velocity and knee alignment in the coronal plane. Our results suggest that the disability is still significant for most patients three months after total knee replacement. A better understand of the impairments and functional limitations following surgery would help clinicians design rehabilitation programs. Moreover, patients should be informed that rehabilitation after total knee replacement is a long process.

  3. The associations between quadriceps muscle strength, power, and knee joint mechanics in knee osteoarthritis: A cross-sectional study.

    PubMed

    Murray, Amanda M; Thomas, Abbey C; Armstrong, Charles W; Pietrosimone, Brian G; Tevald, Michael A

    2015-12-01

    Abnormal knee joint mechanics have been implicated in the pathogenesis and progression of knee osteoarthritis. Deficits in muscle function (i.e., strength and power) may contribute to abnormal knee joint loading. The associations between quadriceps strength, power and knee joint mechanics remain unclear in knee osteoarthritis. Three-dimensional motion analysis was used to collect peak knee joint angles and moments during the first 50% of stance phase of gait in 33 participants with knee osteoarthritis. Quadriceps strength and power were assessed using a knee extension machine. Strength was quantified as the one repetition maximum. Power was quantified as the peak power produced at 40-90% of the one repetition maximum. Quadriceps strength accounted for 15% of the variance in peak knee flexion angle (P=0.016). Quadriceps power accounted for 20-29% of the variance in peak knee flexion angle (P<0.05). Quadriceps power at 90% of one repetition maximum accounted for 9% of the variance in peak knee adduction moment (P=0.05). These data suggest that quadriceps power explains more variance in knee flexion angle and knee adduction moment during gait in knee osteoarthritis than quadriceps strength. Additionally, quadriceps power at multiple loads is associated with knee joint mechanics and therefore should be assessed at a variety of loads. Taken together, these results indicate that quadriceps power may be a potential target for interventions aimed at changing knee joint mechanics in knee osteoarthritis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Tibia valga morphology in osteoarthritic knees: importance of preoperative full limb radiographs in total knee arthroplasty.

    PubMed

    Alghamdi, Ahmed; Rahmé, Michel; Lavigne, Martin; Massé, Vincent; Vendittoli, Pascal-André

    2014-08-01

    Osteoarthritis of the knee is associated with deformities of the lower limb. Tibia valga is a contributing factor to lower limb alignment in valgus knees. We evaluated 97 valgus knees and 100 varus knees. Long-leg films were taken in weight bearing with both knees in full extension. For valgus knees, 52 knees (53%) had a tibia valga deformity. Average tibia valgus deformation was 5.0°. For varus knees, there was only 1 case of tibia valga (1%), with a deformation of 2.5°. The aim of this study was to assess the prevalence of primary tibia valga in valgus and varus knees and understand how it affects our approach to total knee arthroplasty (TKA). We recommend having full-leg length films when planning for TKA in valgus knees.

  5. Knee range of motion after total knee arthroplasty: how important is this as an outcome measure?

    PubMed

    Miner, Andrew L; Lingard, Elizabeth A; Wright, Elizabeth A; Sledge, Clement B; Katz, Jeffrey N

    2003-04-01

    We investigated the relationship of knee range of motion (ROM) and function in a prospective, observational study of primary total knee arthroplasty (TKA). Preoperative and 12-month data were collected on 684 patients, including knee ROM, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and function questionnaire scores, patient satisfaction, and perceived improvement in quality of life (QOL). Only modest correlations were found between knee ROM and WOMAC function (r<0.34). At 12 months we found significantly worse WOMAC function scores for patients with <95 degrees flexion compared with patients with > or =95 degrees (mean, 61.9 vs 75.0; P<.0001). In linear regression models, WOMAC pain and function scores at 12 months were both correlates of patient satisfaction and perceived improvement in QOL (standardized beta>3.5; P<.0001), but knee flexion was not. For assessment of these outcomes, WOMAC function appears to be more important than knee flexion.

  6. Knee-extension-assist for knee-ankle-foot orthoses.

    PubMed

    Spring, Alexander; Kofman, Jonathan; Lemaire, Edward

    2011-01-01

    Individuals with quadriceps muscle weakness often have difficulty generating the knee-extension moments required for common mobility tasks. A new device that provides a knee-extension moment was designed to help individuals perform sit-to-stand and stand-to-sit. The knee-extension-assist (KEA) was designed as a modular component to be incorporated into existing knee-ankle-foot-orthoses (KAFO). The KEA loads a set of springs as the knee flexes under bodyweight and returns the stored energy as an extension moment during knee extension. The springs can be locked in place at the end of flexion to prevent unwanted knee extension while seated. When the affected leg is unloaded, the device disengages, allowing free joint motion. A prototype KEA underwent mechanical testing and biomechanical evaluation on an able-bodied individual during sit-to-stand and stand-to-sit.

  7. Calcaneal Plantar Flexion During the Stance Phase of Gait.

    PubMed

    Stamm, Stacy E; Chiu, Loren Z F

    2016-04-01

    When the rear- and forefoot are constrained, calcaneal plantar flexion may occur, deforming the longitudinal arch. Previous research has reported calcaneal motion relative to the tibia or forefoot; these joint rotations may not accurately describe rotation of the calcaneus alone. This investigation: (1) characterized the calcaneus and leg segment and ankle joint rotations during stance in gait, and (2) described the range of calcaneal plantar flexion in different structural arch types. Men (n = 14) and women (n = 16) performed gait in a motion analysis laboratory. From heel strike to heel off, the leg rotated forward while the calcaneus plantar flexed. Before foot flat, calcaneal plantar flexion was greater than forward leg rotation, resulting in ankle plantar flexion. After foot flat, forward leg rotation was greater than calcaneal plantar flexion, resulting in ankle dorsiflexion. Structural arch type was classified using the longitudinal arch angle. The range of calcaneal plantar flexion from foot flat to heel off was small in low (-2° to -8°), moderate in high (-3° to -12°), and large in normal (-2° to -20°) structural arches. Calcaneal plantar flexion in gait during midstance may reflect functional arch characteristics, which vary depending on structural arch type.

  8. Patient function after a posterior stabilizing total knee arthroplasty: cam-post engagement and knee kinematics.

    PubMed

    Suggs, Jeremy F; Hanson, George R; Park, Sang Eun; Moynihan, Angela L; Li, Guoan

    2008-03-01

    Even though posterior substituting total knee arthroplasty has been widely used in surgery, how the cam-post mechanism (posterior substituting mechanism) affects knee joint kinematics and function in patients is not known. The objective of the present study was to investigate posterior femoral translation, internal tibial rotation, tibiofemoral contact, and cam-post engagement of total knee arthroplasty patients during in vivo weight-bearing flexion. Twenty-four knees with a PS TKA were investigated while performing a single leg weight-bearing lunge from full extension to maximum flexion as images were recorded using a dual fluoroscopic system. The in vivo knee position at each targeted flexion angle was reproduced using 3D TKA models and the fluoroscopic images. The kinematics of the knee was measured from the series of the total knee arthroplasty models. The cam-post engagement was determined when the surface model of the femoral cam overlapped with that of the tibial post. The mean maximum flexion angle for all the subjects was 112.5 +/- 13.1 degrees . The mean flexion angle where cam-post engagement was observed was 91.1 +/- 10.9 degrees . The femur moved anteriorly from 0 degrees to 30 degrees and posteriorly through the rest of the flexion range. The internal tibial rotation increased approximately 6 degrees from full extension to 90 degrees of flexion and decreased slightly with further flexion. Both the medial and lateral contact point moved posteriorly from 0 degrees to 30 degrees , remained relatively constant from 30 degrees to 90 degrees , and then moved further posterior from 90 degrees to maximum flexion. The in vivo cam-post engagement corresponded to increased posterior translation and reduced internal tibial rotation at high flexion of the posterior substituting total knee arthroplasty. The initial cam-post engagement was also mildly correlated with the maximum flexion angle of the knee (R = 0.51, p = 0.019). A later cam-post engagement might

  9. Is patient self-assessment of flexion after TKR able to identify risk of manipulation under anaesthesia?

    PubMed

    Maclean, C; Deakin, A H; Picard, F

    2012-10-01

    Patient self-assessment of postoperative knee flexion following knee replacement was introduced at our institution. This protocol had a dual objective: improve follow-up and act as an early indicator to identify patients at risk of requiring a manipulation under anaesthesia. The aim of our study was to audit the use of this patient self-assessment tool and evaluate whether these outcomes were being achieved. A prospective audit of patients admitted for total knee replacements under the care of one orthopaedic consultant between April and October 2009. Participants were asked to measure and record daily maximum knee flexion whilst sitting, from discharge through to six-week follow-up. Patients were advised to contact the arthroplasty team if flexion reduced by 10° or more for three consecutive days. Patient's documented knee flexion was compared to that measured on discharge and at six weeks postoperatively by clinicians. Seventy-nine participants (82 knees) were included with 61 participants (64 knees) returning data for analysis (78% compliance rate). Comparison of patient and clinician measurements showed a mean difference of +2° with limits of agreements from -12° to +15°. At a mean follow-up of six weeks maximum flexion (measured by clinician) was 99° (95%CI 97°, 102°) and 92% had a 90°flexion or greater. During the audit period, six patients met the criteria to contact the arthroplasty team, however none of them followed this instruction. Patient self-assessment of knee flexion at home with a simple goniometer was accurate enough to be useful and 92% of patients reached 90° maximum flexion at six weeks. However this self-assessment method was not successful as an early indicator to identify patients at risk of requiring a manipulation under anaesthesia. Future studies into alternative identifiers are required. Level III. Investigating a diagnostic test. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  10. Does patella position influence ligament balancing in total knee arthroplasty?

    PubMed

    Yoon, Jung-Ro; Oh, Kwang-Jun; Wang, Joon Ho; Yang, Jae-Hyuk

    2015-07-01

    In vivo comparative gap measurements were performed in three different patella positions (reduced, subluxated and everted) using offset-type-force-controlled-spreader-system. Prospectively, 50 knees were operated by total knee arthroplasty using a navigation-assisted gap-balancing technique. The offset-type-force-controlled-spreader-system was used for gap measurements. This commercially available instrument allows controllable tension in patella-reduced position. The mediolateral gaps of knee extension (0°) and flexion (90°) angle were recorded in three different patella positions; reduced, subluxated and everted. Any gap differences of more than 3 mm were considered as a meaningful difference. Correlation between the difference with the demographic data, preoperative radiologic alignment and intraoperative data was analysed. For statistical analysis, ANOVA and Pearson's correlation test were used. The gaps in patella eversion demonstrated smaller gaps both in knee extension and flexion position compared to the gaps of patella reduction position. The amount of decreased gaps was more definite in knee flexion position. Statistically significant difference was observed for the lateral gap of patella eversion compared to gap of patella reduction in knee flexion position (p < 0.05). There were notable cases of variability in knee flexion position. Significant portion of 12 (24 %) knees of patella subluxation and 33 (66 %) knees of patella evertion demonstrated either increased or decreased gaps in knee flexion position compared to the gaps of patella reduction position. The gaps in patella eversion demonstrated smaller gaps both in knee extension and flexion position compared to the gaps of patella reduction position. The amount of decreased gaps was more definite in knee flexion position. Therefore, the intraoperative patellar positioning has influence on the measurement of the joint gap. Keeping the patella in reduced position is important during gap balancing. I.

  11. Is the pie-crusting technique safe for MCL release in varus deformity correction in total knee arthroplasty?

    PubMed

    Meneghini, R Michael; Daluga, Andrew T; Sturgis, Lindsey A; Lieberman, Jay R

    2013-09-01

    Established for lateral release in TKA, the pie-crusting technique has not been studied for the medial collateral ligament (MCL). In cadaveric knees the MCL was release with a pie-crusting technique in one and traditional technique in the contralateral knee. Along with a control group, each MCL was subjected to mechanical testing. The stiffness, force and stress required to cause ligament elongation were less in the pie-crusting group (p < 0.05) compared to the control group, but were not statistically different than the traditional group. The pie-crusting group demonstrated a characteristic "stair-step" failure mode at the joint line, whereas the traditional group failed elastically at the tibial insertion. MCL pie-crusting is likely technique dependent since failure occurs within the ligament itself and further study is warranted.

  12. Immediate effects of a knee brace with a constraint to knee extension on knee kinematics and ground reaction forces in a stop-jump task.

    PubMed

    Yu, Bing; Herman, Daniel; Preston, Jennifer; Lu, William; Kirkendall, Donald T; Garrett, William E

    2004-01-01

    A small knee flexion angle in landing tasks was identified as a possible risk factor for noncontact anterior cruciate ligament injuries that are common in sports. A specially designed knee brace with a constraint to knee extension would significantly increase the knee flexion angle at the landing of athletic tasks preceded with horizontal movement components, such as stop-jump tasks. Repeated measure design for brace effects. Three-dimensional videographic and force plate data were collected for 10 male and 10 female recreational athletes performing a stop-jump task with and without the specially designed brace. Knee flexion angle at landing, maximum knee flexion angle, and peak ground reaction forces during the stance phase of the stop-jump task were determined for each subject with and without the knee brace. The knee brace decreased the knee flexion angle at the landing by 5 degrees for both genders but did not significantly affect the peak ground reaction forces during the landing. The specially designed knee brace may be a useful device in the prevention and rehabilitation of noncontact anterior cruciate ligament injuries in sports. Copyright 2004 American Orthopaedic Society for Sports Medicine

  13. Is routine splintage following primary total knee replacement necessary? A prospective randomised trial.

    PubMed

    Horton, T C; Jackson, R; Mohan, N; Hambidge, J E

    2002-09-01

    It was hypothesised that routine splintage following primary total knee replacement has no affect on flexion deformity and offers no benefit over simple wool and crepe. Fifty-five patients undergoing primary total knee replacement were entered into a prospective study. The patients were randomly assigned to two groups: The first group was rehabilitated without a splint and the second received an adjustable semi-rigid extension splint (Richards splint) for the first 48 h after surgery. Range of motion measurements were recorded pre-operatively and at 2 days, 1 week and 3 months post-operation by a research nurse blinded to the allocation. No statistically significant difference in flexion deformity was found at any stage (P>0.5). No difference was found in general or wound complications, or requirement for blood transfusion, and the post-operative stay was equal in the two groups. We conclude that routine use of a semi-rigid splint following primary total knee replacement has no advantage over simple wound dressings.

  14. Lessons Learned from Selective Soft-Tissue Release for Gap Balancing in Primary Total Knee Arthroplasty: An Analysis of 1216 Consecutive Total Knee Arthroplasties

    PubMed Central

    Peters, Christopher L.; Jimenez, Chris; Erickson, Jill; Anderson, Mike B.; Pelt, Christopher E.

    2013-01-01

    Background: Soft-tissue releases are commonly necessary to achieve symmetrical flexion and extension gaps in primary total knee arthroplasty performed with a measured resection technique. We reviewed the frequency of required releases according to preoperative alignment and the clinical and radiographic results; associations with failure, reoperations, and complications are presented. Methods: We reviewed 1216 knees that underwent primary total knee arthroplasty from 2004 to 2009; 774 (64%) were in female patients and 442 (36%), in male patients. In the coronal plane, 855 knees had preoperative varus deformity, 123 were neutral, and 238 had valgus deformity. The mean age at the time of the index procedure was 62.7 years (range, twenty-three to ninety-four years), and the mean body mass index was 32.7 kg/m2 (range, 17.4 to 87.9 kg/m2). Clinical outcomes included the Knee Society Score (KSS), implant failure, reoperation, and complications. Radiographs were analyzed for component alignment. Results: The only difference in the total KSS was found at the time of final follow-up between valgus knees with zero releases (total KSS = 178) and those with one or two releases (KSS = 160, p = 0.026). Overall, 407 knees (33.5%) required zero releases, 686 (56.4%) required oneor two releases, and 123 (10.1%) required three or more releases. Among varus knees, 37% required zero releases, 55% required one or two releases, and 7.5% required three or more releases. Among neutral knees, 39% required zero releases, 55% required one or two releases, and 5.7% required three or more releases. Only 17% of valgus knees required zero releases whereas 61% required one or two releases and 21.8% required three or more releases. Valgus knees required more releases than neutral or varus knees did (p < 0.001). Conclusions: Selective soft-tissue release for gap balancing in primary total knee arthroplasty is an effective technique that produced excellent clinical and radiographic results

  15. Surface marker cluster translation, rotation, scaling and deformation: Their contribution to soft tissue artefact and impact on knee joint kinematics.

    PubMed

    Benoit, D L; Damsgaard, M; Andersen, M S

    2015-07-16

    When recording human movement with stereophotogrammetry, skin deformation and displacement (soft tissue artefact; STA) inhibits surface markers' ability to validly represent the movement of the underlying bone. To resolve this issue, the components of marker motions which contribute to STA must be understood. The purpose of this study is to describe and quantify which components of this marker motion (cluster translation, rotation, scaling and deformation) contribute to STA during the stance phase of walking, a cutting manoeuvre, and one-legged hops. In vivo bone pin-based tibio-femoral kinematics of six healthy subjects were used to study skin marker-based STA. To quantify how total cluster translation, rotation, scaling and deformation contribute to STA, a resizable and deformable cluster model was constructed. STA was found to be greater in the thigh than the shank during all three movements. We found that the non-rigid (i.e. scaling and deformation) movements contribute very little to the overall amount of error, rendering surface marker optimisation methods aimed at minimising this component superfluous. The results of the current study indicate that procedures designed to account for cluster translation and rotation during human movement are required to correctly represent the motion of body segments, however reducing marker cluster scaling and deformation will have little effect on STA.

  16. The influence of body mass index and velocity on knee biomechanics during walking.

    PubMed

    Freedman Silvernail, Julia; Milner, Clare E; Thompson, Dixie; Zhang, Songning; Zhao, Xiaopeng

    2013-04-01

    Obesity has been associated with both the development and progression of knee osteoarthritis. Being overweight or obese from a young age is likely to decrease the age of onset for co-morbidities of obesity such as osteoarthritis. However, research on osteoarthritis has thus far focused on older adults. Therefore, the purpose of this study was to determine whether young adults who are overweight or obese exhibit biomechanical risk factors for knee osteoarthritis at either their preferred walking velocity or at 1m/s, which was slower than the preferred velocity. Thirty healthy young adults formed three equal groups according to body mass index. Three dimensional kinetics and kinematics were collected while participants walked overground at both velocities. Joint moments were normalized to fat free weight and height. The preferred walking velocity of obese participants was slower than that of normal weight individuals. There were no differences in knee flexion excursion, peak knee flexion angle, normalized peak knee flexion moment or normalized peak knee adduction moment among groups. Obese participants walked with lower peak knee adduction angle than both overweight and normal body mass index participants and several shifted towards knee abduction. All groups had smaller knee flexion excursion, peak knee flexion angle, peak knee flexion moment and peak knee adduction moment at 1m/s compared to preferred walking velocity. Overall, young and otherwise healthy overweight and obese participants have knee biomechanics during gait at preferred and slow walking velocities that are comparable to normal weight adults.

  17. Runner's Knee

    MedlinePlus

    ... Surgery? A Week of Healthy Breakfasts Shyness Runner's Knee KidsHealth > For Teens > Runner's Knee A A A ... told he had runner's knee. What Is Runner's Knee? Runner's knee is the term doctors use for ...

  18. The Biomechanical Function of the Anterolateral Ligament of the Knee

    PubMed Central

    Parsons, Erin M.; Gee, Albert O.; Spiekerman, Charles; Cavanagh, Peter R.

    2015-01-01

    Background Recent anatomic investigations of the lateral structures of the knee have identified a new ligament, called the anterolateral ligament (ALL). To date, the anterolateral ligament has not been biomechanically tested to determine its function. Hypothesis The ALL of the knee will resist internal rotation at high angles of flexion but will not resist anterior drawer forces. Study Design Controlled laboratory study. Methods Eleven cadaveric knees were subjected to 134 N of anterior drawer at flexion angles between 0° and 90° and separately to 5 N·m of internal rotation at the same flexion angles. The in situ forces of the ALL, anterior cruciate ligament (ACL), and lateral collateral ligament (LCL) were determined by the principle of superposition. Results The contribution of the ALL during internal rotation increased significantly with increasing flexion, whereas that of the ACL decreased significantly. At knee flexion angles greater than 30°, the contribution of the ALL exceeded that of the ACL. During anterior drawer, the forces in the ALL were significantly less than the forces in the ACL at all flexion angles (P < .001). The forces in the LCL were significantly less than those in either the ACL or the ALL at all flexion angles for both anterior drawer and internal rotation (P < .001). Conclusion The ALL is an important stabilizer of internal rotation at flexion angles greater than 35°; however, it is minimally loaded during anterior drawer at all flexion angles. The ACL is the primary resister during anterior drawer at all flexion angles and during internal rotation at flexion angles less than 35°. Clinical Relevance Damage to the ALL of the knee could result in knee instability at high angles of flexion. It is possible that a positive pivot-shift sign may be observed in some patients with an intact ACL but with damage to the ALL. This work may have implications for extra-articular reconstruction in patients with chronic anterolateral instability

  19. The biomechanical function of the anterolateral ligament of the knee.

    PubMed

    Parsons, Erin M; Gee, Albert O; Spiekerman, Charles; Cavanagh, Peter R

    2015-03-01

    Recent anatomic investigations of the lateral structures of the knee have identified a new ligament, called the anterolateral ligament (ALL). To date, the anterolateral ligament has not been biomechanically tested to determine its function. The ALL of the knee will resist internal rotation at high angles of flexion but will not resist anterior drawer forces. Controlled laboratory study. Eleven cadaveric knees were subjected to 134 N of anterior drawer at flexion angles between 0° and 90° and separately to 5 N·m of internal rotation at the same flexion angles. The in situ forces of the ALL, anterior cruciate ligament (ACL), and lateral collateral ligament (LCL) were determined by the principle of superposition. The contribution of the ALL during internal rotation increased significantly with increasing flexion, whereas that of the ACL decreased significantly. At knee flexion angles greater than 30°, the contribution of the ALL exceeded that of the ACL. During anterior drawer, the forces in the ALL were significantly less than the forces in the ACL at all flexion angles (P < .001). The forces in the LCL were significantly less than those in either the ACL or the ALL at all flexion angles for both anterior drawer and internal rotation (P < .001). The ALL is an important stabilizer of internal rotation at flexion angles greater than 35°; however, it is minimally loaded during anterior drawer at all flexion angles. The ACL is the primary resister during anterior drawer at all flexion angles and during internal rotation at flexion angles less than 35°. Damage to the ALL of the knee could result in knee instability at high angles of flexion. It is possible that a positive pivot-shift sign may be observed in some patients with an intact ACL but with damage to the ALL. This work may have implications for extra-articular reconstruction in patients with chronic anterolateral instability. © 2015 The Author(s).

  20. Knee Brace Would Lock And Unlock Automatically

    NASA Technical Reports Server (NTRS)

    Myers, Neill; Forbes, John; Shadoan, Mike; Baker, Kevin

    1995-01-01

    Proposed knee brace designed to aid rehabilitation of person who suffered some muscle damage in leg. Not limited to locking in straight-leg position and, instead, locks at any bend angle. Does not prevent knee from bearing weight. Instead, knee brace allows knee to bear weight and locks only when foot and lower leg bear weight. Thus, brace prevents flexion that wearer desired to prevent but could not prevent because of weakened muscles. Knee bends freely to exercise knee-related muscles. Knee brace strapped at upper end to leg above knee, and anchored at lower end by stirrup under foot. Joint mechanism (identical mechanisms used in left and right assemblies) allows knee joint to flex freely except when weight applied to heel.

  1. Knee Brace Would Lock And Unlock Automatically

    NASA Technical Reports Server (NTRS)

    Myers, Neill; Forbes, John; Shadoan, Mike; Baker, Kevin

    1995-01-01

    Proposed knee brace designed to aid rehabilitation of person who suffered some muscle damage in leg. Not limited to locking in straight-leg position and, instead, locks at any bend angle. Does not prevent knee from bearing weight. Instead, knee brace allows knee to bear weight and locks only when foot and lower leg bear weight. Thus, brace prevents flexion that wearer desired to prevent but could not prevent because of weakened muscles. Knee bends freely to exercise knee-related muscles. Knee brace strapped at upper end to leg above knee, and anchored at lower end by stirrup under foot. Joint mechanism (identical mechanisms used in left and right assemblies) allows knee joint to flex freely except when weight applied to heel.

  2. Forces and moments on the knee during kneeling and squatting.

    PubMed

    Pollard, Jonisha P; Porter, William L; Redfern, Mark S

    2011-08-01

    Euler angle decomposition and inverse dynamics were used to determine the knee angles and net forces and moments applied to the tibia during kneeling and squatting with and without kneepads for 10 subjects in four postures: squatting (Squat), kneeling on the right knee (One Knee), bilateral kneeling near full flexion (Near Full) and bilateral kneeling near 90° flexion (Near 90). Kneepads affected the knee flexion (p = .002), medial forces (p = .035), and internal rotation moments (p = .006). Squat created loading conditions that had higher varus (p < .001) and resultant moments (p = .027) than kneeling. One Knee resulted in the highest force magnitudes and net moments (p < .001) of the kneeling postures. Thigh-calf and heel-gluteus contact forces decreased the flexion moment on average by 48% during Squat and Near Full.

  3. Effects of childhood obesity on three-dimensional knee joint biomechanics during walking.

    PubMed

    Gushue, David L; Houck, Jeff; Lerner, Amy L

    2005-01-01

    Despite the increasing percentages of children who are overweight, few studies have investigated their gait patterns. The purpose of this study was to quantify the three-dimensional knee joint kinematics and kinetics during walking in children of varying body mass and to identify effects associated with obesity. Three-dimensional kinematics and kinetics were collected from children of normal weight and overweight during normal gait using surface-mounted infrared emitting diodes and a force plate. The overweight group walked with a significantly lower peak knee flexion angle during early stance, and no significant differences in peak internal knee extension moments were found between groups. However, the overweight group showed a significantly higher peak internal knee abduction moment during early stance. These data suggest that although overweight children may develop a gait adaptation to maintain a similar knee extensor load, they may not be able to compensate for alterations in the frontal plane, which may lead to increased medial compartment joint loads. Therefore, assuming that the development of varus angular deformities of the knee joint and, in the longer term, medial compartment osteoarthritis are influenced by cumulative stress, this study supports the understanding that childhood obesity may impart a greater risk for the development of these diseases.

  4. Reliability and measurement precision of concentric-to-isometric and eccentric-to-isometric knee active joint position sense tests in uninjured physically active adults.

    PubMed

    Clark, Nicholas C; Akins, Jonathan S; Heebner, Nicholas R; Sell, Timothy C; Abt, John P; Lovalekar, Mita; Lephart, Scott M

    2016-03-01

    Proprioception is important because it is used by the central nervous system to mediate muscle control of joint stability, posture, and movement. Knee active joint position sense (AJPS) is one representation of knee proprioception. The purpose of this study was to establish the intra-tester, inter-session, test-retest reliability of concentric-to-isometric (seated knee extension; prone knee flexion) and eccentric-to-isometric (seated knee flexion; prone knee extension) knee AJPS tests in uninjured adults. Descriptive. University laboratory. Six males, six females (age 26.2 ± 5.7 years; height 171.1 ± 9.6 cm; mass 71.1 ± 16.6 kg). Mean absolute error (AE; °); intraclass correlation coefficient (ICC) (2,1); standard error of measurement (SEM; °). Mean AE ranged from 3.18° to 5.97° across tests. The ICCs and SEMs were: seated knee extension 0.13, 1.3°; prone knee flexion 0.51, 1.2°; seated knee flexion 0.31, 1.7°; prone knee extension 0.87, 1.4°. The prone knee flexion and prone knee extension tests demonstrated moderate to good reliability. Prone knee flexion and prone knee extension AJPS tests may be useful in cross-sectional studies estimating how proprioception contributes to knee functional joint stability or prospective studies estimating the role of proprioception in the onset of knee injury. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Open Knee: Open Source Modeling & Simulation to Enable Scientific Discovery and Clinical Care in Knee Biomechanics

    PubMed Central

    Erdemir, Ahmet

    2016-01-01

    Virtual representations of the knee joint can provide clinicians, scientists, and engineers the tools to explore mechanical function of the knee and its tissue structures in health and disease. Modeling and simulation approaches such as finite element analysis also provide the possibility to understand the influence of surgical procedures and implants on joint stresses and tissue deformations. A large number of knee joint models are described in the biomechanics literature. However, freely accessible, customizable, and easy-to-use models are scarce. Availability of such models can accelerate clinical translation of simulations, where labor intensive reproduction of model development steps can be avoided. The interested parties can immediately utilize readily available models for scientific discovery and for clinical care. Motivated by this gap, this study aims to describe an open source and freely available finite element representation of the tibiofemoral joint, namely Open Knee, which includes detailed anatomical representation of the joint's major tissue structures, their nonlinear mechanical properties and interactions. Three use cases illustrate customization potential of the model, its predictive capacity, and its scientific and clinical utility: prediction of joint movements during passive flexion, examining the role of meniscectomy on contact mechanics and joint movements, and understanding anterior cruciate ligament mechanics. A summary of scientific and clinically directed studies conducted by other investigators are also provided. The utilization of this open source model by groups other than its developers emphasizes the premise of model sharing as an accelerator of simulation-based medicine. Finally, the imminent need to develop next generation knee models are noted. These are anticipated to incorporate individualized anatomy and tissue properties supported by specimen-specific joint mechanics data for evaluation, all acquired in vitro from varying age

  6. Does the Q − H index show a stronger relationship than the H:Q ratio in regard to knee pain during daily activities in patients with knee osteoarthritis?

    PubMed Central

    Fujita, Remi; Matsui, Yasumoto; Harada, Atsushi; Takemura, Marie; Kondo, Izumi; Nemoto, Tetsuya; Sakai, Tadahiro; Hiraiwa, Hideki; Ota, Susumu

    2016-01-01

    [Purpose] The purpose of this study was to elucidate the relationship between knee muscle strength and knee pain in activities of daily living, based on consideration of the difference between extension and flexion strength (Q − H) and the hamstring:quadriceps (H:Q) ratio in patients with knee osteoarthritis. [Subjects and Methods] The participants were 78 females with knee osteoarthritis, and a total of 133 knees that had not been treated surgically were the targets of this research. The legs were divided according to dominance. Isometric knee extension and flexion muscle strength and knee pain during activities of daily living were measured. The H:Q ratio (flexion/extension muscle strength) and the difference between extension and flexion strength, (extension muscle strength/weight) minus (flexion muscle strength/weight), that is, Q − H, were calculated. The correlation between these indices and the knee pain score during activities of daily living was investigated. [Results] Greater knee pain during activities of daily living was related to lower knee extension muscle strength and Q − H in both the dominant and nondominant legs. Knee flexion muscle strength and the H:Q ratio were not significantly correlated with knee pain during any activities of daily living. [Conclusion] Knee extension muscle strength and Q − H were found to be significantly correlated with knee pain during activities of daily living, whereas the H:Q ratio was not. PMID:28174444

  7. An improved OpenSim gait model with multiple degrees of freedom knee joint and knee ligaments.

    PubMed

    Xu, Hang; Bloswick, Donald; Merryweather, Andrew

    2015-08-01

    Musculoskeletal models are widely used to investigate joint kinematics and predict muscle force during gait. However, the knee is usually simplified as a one degree of freedom joint and knee ligaments are neglected. The aim of this study was to develop an OpenSim gait model with enhanced knee structures. The knee joint in this study included three rotations and three translations. The three knee rotations and mediolateral translation were independent, with proximodistal and anteroposterior translations occurring as a function of knee flexion/extension. Ten elastic elements described the geometrical and mechanical properties of the anterior and posterior cruciate ligaments (ACL and PCL), and the medial and lateral collateral ligaments (MCL and LCL). The three independent knee rotations were evaluated using OpenSim to observe ligament function. The results showed that the anterior and posterior bundles of ACL and PCL (aACL, pACL and aPCL, pPCL) intersected during knee flexion. The aACL and pACL mainly provided force during knee flexion and adduction, respectively. The aPCL was slack throughout the range of three knee rotations; however, the pPCL was utilised for knee abduction and internal rotation. The LCL was employed for knee adduction and rotation, but was slack beyond 20° of knee flexion. The MCL bundles were mainly used during knee adduction and external rotation. All these results suggest that the functions of knee ligaments in this model approximated the behaviour of the physical knee and the enhanced knee structures can improve the ability to investigate knee joint biomechanics during various gait activities.

  8. Structure, sex, and strength and knee and hip kinematics during landing.

    PubMed

    Howard, Jennifer S; Fazio, Melisa A; Mattacola, Carl G; Uhl, Timothy L; Jacobs, Cale A

    2011-01-01

    Researchers have observed that medial knee collapse is a mechanism of knee injury. Lower extremity alignment, sex, and strength have been cited as contributing to landing mechanics. To determine the relationship among measurements of asymmetry of unilateral hip rotation (AUHR); mobility of the foot, which we described as relative arch deformity (RAD); hip abduction-external rotation strength; sex; and medial collapse of the knee during a single-leg jump landing. We hypothesized that AUHR and RAD would be positively correlated with movements often associated with medial collapse of the knee, including hip adduction and internal rotation excursions and knee abduction and rotation excursions. Descriptive laboratory study. Research laboratory. Thirty women and 15 men (age = 21 ± 2 years, height = 171.7 ± 9.5 cm, mass = 68.4 ± 9.5 kg) who had no history of surgery or recent injury and who participated in regular physical activity volunteered. Participants performed 3 double-leg forward jumps with a single-leg landing. Three-dimensional kinematic data were sampled at 100 Hz using an electromagnetic tracking system. We evaluated AUHR and RAD on the preferred leg and evaluated isometric peak hip abductor-external rotation torque. We assessed AUHR by calculating the difference between internal and external hip rotation in the prone position (AUHR = internal rotation - external rotation). We evaluated RAD using the Arch Height Index Measurement System. Correlations and linear regression analyses were used to assess relationships among AUHR, RAD, sex, peak hip abduction-external rotation torque, and kinematic variables for 3-dimensional motion of the hip and knee. The dependent variables were joint angles at contact and joint excursions between contact and peak knee flexion. We found that AUHR was correlated with hip adduction excursion (R = 0.36, P = .02). Asymmetry of unilateral hip rotation, sex, and peak hip abduction-external rotation torque were predictive of knee

  9. Structure, Sex, and Strength and Knee and Hip Kinematics During Landing

    PubMed Central

    Howard, Jennifer S; Fazio, Melisa A.; Mattacola, Carl G.; Uhl, Timothy L.; Jacobs, Cale A.

    2011-01-01

    Context: Researchers have observed that medial knee collapse is a mechanism of knee injury. Lower extremity alignment, sex, and strength have been cited as contributing to landing mechanics. Objective: To determine the relationship among measurements of asymmetry of unilateral hip rotation (AUHR); mobility of the foot, which we described as relative arch deformity (RAD); hip abduction–external rotation strength; sex; and me-dial collapse of the knee during a single-leg jump landing. We hypothesized that AUHR and RAD would be positively correlated with movements often associated with medial collapse of the knee, including hip adduction and internal rotation excursions and knee abduction and rotation excursions. Design: Descriptive laboratory study. Setting: Research laboratory. Patients or Other Participants: Thirty women and 15 men (age = 21 ± 2 years, height = 171.7 ± 9.5 cm, mass = 68.4 ± 9.5 kg) who had no history of surgery or recent injury and who participated in regular physical activity volunteered. Interventions : Participants performed 3 double-leg forward jumps with a single-leg landing. Three-dimensional kinematic data were sampled at 100 Hz using an electromagnetic tracking system. We evaluated AUHR and RAD on the preferred leg and evaluated isometric peak hip abductor–external rotation torque. We assessed AUHR by calculating the difference between internal and external hip rotation in the prone position (AUHR = internal rotation – external rotation). We evaluated RAD using the Arch Height Index Measurement System. Correlations and linear regression analyses were used to assess relationships among AUHR, RAD, sex, peak hip abduction–external rotation torque, and kinematic variables for 3-dimensional motion of the hip and knee. Main Outcome Measure(s): The dependent variables were joint angles at contact and joint excursions between contact and peak knee flexion. Results: We found that AUHR was correlated with hip adduction excursion (R = 0

  10. Knee Proprioception and Strength and Landing Kinematics During a Single-Leg Stop-Jump Task

    PubMed Central

    Nagai, Takashi; Sell, Timothy C; House, Anthony J; Abt, John P; Lephart, Scott M

    2013-01-01

    Context The importance of the sensorimotor system in maintaining a stable knee joint has been recognized. As individual entities, knee-joint proprioception, landing kinematics, and knee muscles play important roles in functional joint stability. Preventing knee injuries during dynamic tasks requires accurate proprioceptive information and adequate muscular strength. Few investigators have evaluated the relationship between knee proprioception and strength and landing kinematics. Objective To examine the relationship between knee proprioception and strength and landing kinematics. Design Cross-sectional study. Setting University research laboratory. Patients or Other Participants Fifty physically active men (age = 26.4 ± 5.8 years, height = 176.5 ± 8.0 cm, mass = 79.8 ± 16.6 kg). Intervention(s) Three tests were performed. Knee conscious proprioception was evaluated via threshold to detect passive motion (TTDPM). Knee strength was evaluated with a dynamometer. A 3-dimensional biomechanical analysis of a single-legged stop-jump task was used to calculate initial contact (IC) knee-flexion angle and knee-flexion excursion. Main Outcome Measure(s) The TTDPM toward knee flexion and extension, peak knee flexion and extension torque, and IC knee-flexion angle and knee flexion excursion. Linear correlation and stepwise multiple linear regression analyses were used to evaluate the relationships of both proprioception and strength against landing kinematics. The α level was set a priori at .05. Results Enhanced TTDPM and greater knee strength were positively correlated with greater IC knee-flexion angle (r range = 0.281–0.479, P range = .001–.048). The regression analysis revealed that 27.4% of the variance in IC knee-flexion angle could be accounted for by knee-flexion peak torque and TTDPM toward flexion (P = .001). Conclusions The current research highlighted the relationship between knee proprioception and strength and landing kinematics. Individuals with enhanced

  11. Percutaneous quadriceps tendon pie-crusting release of extension contracture of the knee.

    PubMed

    Liu, H X; Wen, H; Hu, Y Z; Yu, H C; Pan, X Y

    2014-05-01

    To release extension contracture of the knee, the authors used a minimally invasive technique: percutaneous quadriceps tendon pie-crusting release. Percutaneous pie-crusting release was performed using an 18-gauge needle to puncture the stiff fibrous band of the distal and lateral quadriceps tendon under maximum knee flexion. Quadriceps contracture was gradually released by multiple needle punctures. A knee brace was prescribed for one week and knee flexion exercises were performed on the first postoperative day. This technique was performed in seven post-traumatic stiff knees and five stiff total knee arthroplasties. Mean maximum flexion increased from 37° preoperatively to 50° after arthrolysis and 107(o) after pie-crusting. At a mean follow-up of eight months, mean maximum flexion was 103°. There were no major complications. The technique of quadriceps tendon pie-crusting release is a simple, minimally invasive and effective treatment for knee extension contracture.

  12. In vivo articular cartilage deformation: noninvasive quantification of intratissue strain during joint contact in the human knee

    NASA Astrophysics Data System (ADS)

    Chan, Deva D.; Cai, Luyao; Butz, Kent D.; Trippel, Stephen B.; Nauman, Eric A.; Neu, Corey P.

    2016-01-01

    The in vivo measurement of articular cartilage deformation is essential to understand how mechanical forces distribute throughout the healthy tissue and change over time in the pathologic joint. Displacements or strain may serve as a functional imaging biomarker for healthy, diseased, and repaired tissues, but unfortunately intratissue cartilage deformation in vivo is largely unknown. Here, we directly quantified for the first time deformation patterns through the thickness of tibiofemoral articular cartilage in healthy human volunteers. Magnetic resonance imaging acquisitions were synchronized with physiologically relevant compressive loading and used to visualize and measure regional displacement and strain of tibiofemoral articular cartilage in a sagittal plane. We found that compression (of 1/2 body weight) applied at the foot produced a sliding, rigid-body displacement at the tibiofemoral cartilage interface, that loading generated subject- and gender-specific and regionally complex patterns of intratissue strains, and that dominant cartilage strains (approaching 12%) were in shear. Maximum principle and shear strain measures in the tibia were correlated with body mass index. Our MRI-based approach may accelerate the development of regenerative therapies for diseased or damaged cartilage, which is currently limited by the lack of reliable in vivo methods for noninvasive assessment of functional changes following treatment.

  13. In vivo articular cartilage deformation: noninvasive quantification of intratissue strain during joint contact in the human knee

    PubMed Central

    Chan, Deva D.; Cai, Luyao; Butz, Kent D.; Trippel, Stephen B.; Nauman, Eric A.; Neu, Corey P.

    2016-01-01

    The in vivo measurement of articular cartilage deformation is essential to understand how mechanical forces distribute throughout the healthy tissue and change over time in the pathologic joint. Displacements or strain may serve as a functional imaging biomarker for healthy, diseased, and repaired tissues, but unfortunately intratissue cartilage deformation in vivo is largely unknown. Here, we directly quantified for the first time deformation patterns through the thickness of tibiofemoral articular cartilage in healthy human volunteers. Magnetic resonance imaging acquisitions were synchronized with physiologically relevant compressive loading and used to visualize and measure regional displacement and strain of tibiofemoral articular cartilage in a sagittal plane. We found that compression (of 1/2 body weight) applied at the foot produced a sliding, rigid-body displacement at the tibiofemoral cartilage interface, that loading generated subject- and gender-specific and regionally complex patterns of intratissue strains, and that dominant cartilage strains (approaching 12%) were in shear. Maximum principle and shear strain measures in the tibia were correlated with body mass index. Our MRI-based approach may accelerate the development of regenerative therapies for diseased or damaged cartilage, which is currently limited by the lack of reliable in vivo methods for noninvasive assessment of functional changes following treatment. PMID:26752228

  14. Mobile Sensor Application for Kinematic Detection of the Knees

    PubMed Central

    Suputtitada, Areerat; Khovidhungij, Watcharapong

    2015-01-01

    Objective To correctly measure the knee joint angle, this study utilized a Qualisys motion capture system and also used it as the reference to assess the validity of the study's Inertial Measurement Unit (IMU) system that consisted of four IMU sensors and the Knee Angle Recorder software. The validity was evaluated by the root mean square (RMS) of different angles and the intraclass correlation coefficient (ICC) values between the Qualisys system and the IMU system. Methods Four functional knee movement tests for ten healthy participants were investigated, which were the knee flexion test, the hip and knee flexion test, the forward step test and the leg abduction test, and the walking test. Results The outcomes of the knee flexion test, the hip and knee flexion test, the forward step test, and the walking test showed that the RMS of different angles were less than 6°. The ICC values were in the range of 0.84 to 0.99. However, the leg abduction test showed a poor correlation in the measurement of the knee abduction-adduction movement. Conclusion The IMU system used in this study is a new good method to measure the knee flexion-extension movement. PMID:26361597

  15. Contralateral compensation with knee impairment.

    PubMed

    Nuzzo, R M; Jolly, J; Langrana, N A

    1987-10-01

    Knee motion of four healthy teenagers was unilaterally impaired by means of cast braces. Computerized analysis from video recording of walking was used to study the compensatory effects and to compare them with six patients. Restricted knee flexion caused little change in stance-phase knee motion on the restricted side. The unimpaired knee displayed exaggerated stance phase flexion and phase shifts, which in turn produced pelvic vaulting. The forces on the braces were high. Impairments to extension produced bilateral crouch without loss of flexion extension patterns within the limits of the impairment. Fatigue was more prominent than with blocks to flexion. Circumduction was found to be overrated as a compensation for stiff-leggedness. Lateral shift to the well side, combined with freezing of the well-side stance adduction, was a frequently used effective clearance mechanism. Phasic changes in motion of many body parts may combine to produce low-level pelvic displacement, especially when clinical weakness is present. Shortened stride length is the most sensitive indicator of this phenomenon. Graphs of individual joint motion do not easily convey the important phasic relationships that are fundamental to that motion and to the interpretation of its effects. Stick figures were better for analysis of this aspect of motion analysis, even though they are more subjective.

  16. Six degree-of-freedom knee joint kinematics in obese individuals with knee pain during gait.

    PubMed

    Li, Jing-Sheng; Tsai, Tsung-Yuan; Felson, David T; Li, Guoan; Lewis, Cara L

    2017-01-01

    Knee joint pain is a common symptom in obese individuals and walking is often prescribed as part of management programs. Past studies in obese individuals have focused on standing alignment and kinematics in the sagittal and coronal planes. Investigation of 6 degree-of-freedom (6DOF) knee joint kinematics during standing and gait is important to thoroughly understand knee function in obese individuals with knee pain. This study aimed to investigate the 6DOF knee joint kinematics in standing and during gait in obese patients using a validated fluoroscopic imaging system. Ten individuals with obesity and knee pain were recruited. While standing, the knee was in 7.4±6.3°of hyperextension, 2.8±3.3° of abduction and 5.6±7.3° of external rotation. The femoral center was located 0.7±3.1mm anterior and 5.1±1.5mm medial to the tibial center. During treadmill gait, the sagittal plane motion, i.e., flexion/extension and anterior-posterior translation, showed a clear pattern. Specifically, obese individuals with knee pain maintained the knee in more flexion and more anterior tibial translation during most of the stance phase of the gait cycle and had a reduced total range of knee flexion when compared to a healthy non-obese group. In conclusion, obese individuals with knee pain used hyperextension knee posture while standing, but maintained the knee in more flexion during gait with reduced overall range of motion in the 6DOF analysis.

  17. Six degree-of-freedom knee joint kinematics in obese individuals with knee pain during gait

    PubMed Central

    Li, Jing-Sheng; Tsai, Tsung-Yuan; Felson, David T.; Li, Guoan; Lewis, Cara L.

    2017-01-01

    Knee joint pain is a common symptom in obese individuals and walking is often prescribed as part of management programs. Past studies in obese individuals have focused on standing alignment and kinematics in the sagittal and coronal planes. Investigation of 6 degree-of-freedom (6DOF) knee joint kinematics during standing and gait is important to thoroughly understand knee function in obese individuals with knee pain. This study aimed to investigate the 6DOF knee joint kinematics in standing and during gait in obese patients using a validated fluoroscopic imaging system. Ten individuals with obesity and knee pain were recruited. While standing, the knee was in 7.4±6.3°of hyperextension, 2.8±3.3° of abduction and 5.6±7.3° of external rotation. The femoral center was located 0.7±3.1mm anterior and 5.1±1.5mm medial to the tibial center. During treadmill gait, the sagittal plane motion, i.e., flexion/extension and anterior-posterior translation, showed a clear pattern. Specifically, obese individuals with knee pain maintained the knee in more flexion and more anterior tibial translation during most of the stance phase of the gait cycle and had a reduced total range of knee flexion when compared to a healthy non-obese group. In conclusion, obese individuals with knee pain used hyperextension knee posture while standing, but maintained the knee in more flexion during gait with reduced overall range of motion in the 6DOF analysis. PMID:28339477

  18. Paraplegic flexion contracture of hip joints: An unsolvable problem

    PubMed Central

    Bhattacharyya, Sailendra

    2016-01-01

    Paraplegic flexion contracture of hip joints beyond 90° is a difficult condition to treat for any orthopedic surgeon. There is no fixed protocol of treatment described, by and large it is individualized. A 20 year old female presented with paraplegia for last 15 years due to irrecoverable spinal cord disease with complete sensory and motor loss of both lower extremities and was admitted with acute flexion contracture of both hip joints with trunk resting on thighs. She underwent bilateral proximal femoral resection. Both hip joints were straight immediately after surgery and patient could lie on her back. In a course of time, she started sitting on her buttocks, led a comfortable wheelchair life with a sitting balance. Proximal femoral resection is an effective method to treat long standing irrecoverable paraplegic acute flexion deformity of the hip joint. PMID:27904226

  19. Paraplegic flexion contracture of hip joints: An unsolvable problem.

    PubMed

    Bhattacharyya, Sailendra

    2016-01-01

    Paraplegic flexion contracture of hip joints beyond 90° is a difficult condition to treat for any orthopedic surgeon. There is no fixed protocol of treatment described, by and large it is individualized. A 20 year old female presented with paraplegia for last 15 years due to irrecoverable spinal cord disease with complete sensory and motor loss of both lower extremities and was admitted with acute flexion contracture of both hip joints with trunk resting on thighs. She underwent bilateral proximal femoral resection. Both hip joints were straight immediately after surgery and patient could lie on her back. In a course of time, she started sitting on her buttocks, led a comfortable wheelchair life with a sitting balance. Proximal femoral resection is an effective method to treat long standing irrecoverable paraplegic acute flexion deformity of the hip joint.

  20. A dynamic multibody model of the physiological knee to predict internal loads during movement in gravitational field.

    PubMed

    Bersini, Simone; Sansone, Valerio; Frigo, Carlo A

    2016-01-01

    Obtaining tibio-femoral (TF) contact forces, ligament deformations and loads during daily life motor tasks would be useful to better understand the aetiopathogenesis of knee joint diseases or the effects of ligament reconstruction and knee arthroplasty. However, methods to obtain this information are either too simplified or too computationally demanding to be used for clinical application. A multibody dynamic model of the lower limb reproducing knee joint contact surfaces and ligaments was developed on the basis of magnetic resonance imaging. Several clinically relevant conditions were simulated, including resistance to hyperextension, varus-valgus stability, anterior-posterior drawer, loaded squat movement. Quadriceps force, ligament deformations and loads, and TF contact forces were computed. During anterior drawer test the anterior cruciate ligament (ACL) was maximally loaded when the knee was extended (392 N) while the posterior cruciate ligament (PCL) was much more stressed during posterior drawer when the knee was flexed (319 N). The simulated loaded squat revealed that the anterior fibres of ACL become inactive after 60° of flexion in conjunction with PCL anterior bundle activation, while most components of the collateral ligaments exhibit limited length changes. Maximum quadriceps and TF forces achieved 3.2 and 4.2 body weight, respectively. The possibility to easily manage model parameters and the low computational cost of each simulation represent key points of the present project. The obtained results are consistent with in vivo measurements, suggesting that the model can be used to simulate complex and clinically relevant exercises.

  1. Posterior cruciate ligament balancing in total knee arthroplasty: a numerical study with a dynamic force controlled knee model

    PubMed Central

    2014-01-01

    Background Adequate soft tissue balancing is a key factor for a successful result after total knee arthroplasty (TKA). Posterior cruciate ligament (PCL) is the primary restraint to posterior translation of the tibia after cruciate retaining TKA and is also responsible for the amount of joint compression. However, it is complex to quantify the amount of ligament release with its effects on load bearing and kinematics in TKA and limited both in vivo and in vitro. The goal of this study was to create a dynamic and deformable finite element model of a full leg and analyze a stepwise release of the PCL regarding knee kinematics, pressure distribution and ligament stresses. Methods A dynamic finite element model was developed in Ansys V14.0 based on boundary conditions of an existing knee rig. A cruciate retraining knee prosthesis was virtually implanted. Ligament and muscle structures were simulated with modified spring elements. Linear elastic materials were defined for femoral component, inlay and patella cartilage. A restart algorithm was developed and implemented into the finite element simulation to hold the ground reaction force constant by adapting quadriceps force. After simulating the unreleased PCL model, two models were developed and calculated with the same boundary conditions with a 50% and 75% release of the PCL stiffness. Results From the beginning of the simulation to approximately 35° of flexion, tibia moves posterior related to the femur and with higher flexion anteriorly. Anterior translation of the tibia ranged from 5.8 mm for unreleased PCL to 3.7 mm for 75% PCL release (4.9 mm 50% release). A decrease of maximum von Mises equivalent stress on the inlay was given with PCL release, especially in higher flexion angles from 11.1 MPa for unreleased PCL to 8.9 MPa for 50% release of the PCL and 7.8 MPa for 75% release. Conclusions Our study showed that dynamic FEM is an effective method for simulation of PCL balancing in knee arthroplasty. A tight

  2. Strength does not influence knee function in the ACL-deficient knee but is a correlate of knee function in the and ACL-reconstructed knee.

    PubMed

    Hohmann, Erik; Bryant, Adam; Tetsworth, Kevin

    2016-04-01

    Knee function, whether anterior cruciate ligament (ACL)-deficient or ACL-reconstructed, is related to many conditions, and no single biomechanical variable can be used to definitively assess knee performance. The purpose of this study was to investigate the relationship between extension and flexion muscle strength and knee function in patients prior and following ACL reconstruction. 44 ACL-deficient patients with a mean age of 26.6 years were tested between 3 and 6 months following an acute injury and 2 years following ACL reconstruction. All reconstructed patients underwent surgical reconstruction within 6 months of ACL injury using bone-patellar tendon and interference screws. The Cincinnati knee rating system was used to assess knee function. Muscle strength was assessed with the Biodex™ Dynamometer. Isokinetic concentric and eccentric flexion and extension peak torque (Nm/kg) was tested at three different speeds: 60°/s, 120°/s and 180°/s. Isometric strength was tested in 30° and 60° of knee flexion. Both the involved and non-involved legs were tested to calculate symmetry indices. The mean Cincinnati score in the ACL-deficient patient was 62.0 ± 14.5 (range 36-84) and increased to 89.3 ± 9.5 (range 61-100) in the ACL-reconstructed patient. Significant relationships between knee function and muscle strength in the ACL-deficient group were observed for knee symmetry indices (r = 0.38-0.50, p = 0.0001-0.05). In the ACL-reconstructed group significant relationships between knee functionality were observed for isometric and isokinetic peak torque of the involved limb (r = 0.46-0.71, p = 0.0001-0.007). The findings of this study suggest that neither extension nor flexion peak torque were correlates of knee function in the ACL-deficient knee. However, leg symmetry indices were correlated to knee function. In the ACL-reconstructed knee, knee symmetry indices were not related to knee function but extension and flexion isokinetic concentric and

  3. Effects of a knee extension constraint brace on lower extremity movements after ACL reconstruction.

    PubMed

    Stanley, Christopher J; Creighton, R Alexander; Gross, Michael T; Garrett, William E; Yu, Bing

    2011-06-01

    Patients have high reinjury rates after ACL reconstruction. Small knee flexion angles and large peak posterior ground reaction forces in landing tasks increase ACL loading. We determined the effects of a knee extension constraint brace on knee flexion angle, peak posterior ground reaction force, and movement speed in functional activities of patients after ACL reconstruction. Six male and six female patients 3.5 to 6.5 months after ACL reconstruction participated in the study. Three-dimensional videographic and force plate data were collected while patients performed level walking, jogging, and stair descent wearing a knee extension constraint brace, wearing a nonconstraint brace, and not wearing a knee brace. Knee flexion angle at initial foot contact with the ground, peak posterior ground reaction force, and movement speed were compared across brace conditions and between genders. Wearing the knee extension constraint brace increased the knee flexion angle at initial foot contact for each activity when compared with the other two brace conditions. Wearing the knee extension constraint brace also decreased peak posterior ground reaction force during walking but not during jogging and stair descent. Although the knee extension constraint brace did not consistently reduce the peak posterior ground reaction force in all functional activities, it consistently increased knee flexion angle and should reduce ACL loading as suggested by previous studies. These results suggest the knee extension constraint brace has potential as a rehabilitation tool to alter lower extremity movement patterns of patients after ACL reconstruction to address high reinjury rates.

  4. The effectiveness of posterior knee capsulotomies and knee extension osteotomies in crouched gait in children with cerebral palsy.

    PubMed

    Taylor, Daveda; Connor, Justin; Church, Chris; Lennon, Nancy; Henley, John; Niiler, Tim; Miller, Freeman

    2016-11-01

    Crouched gait is common in children with cerebral palsy (CP), and there are various treatment options. This study evaluated the effectiveness of single-event multilevel surgery including posterior knee capsulotomy or distal femoral extension osteotomy to correct knee flexion contracture in children with CP. Gait analyses were carried out to evaluate gait preoperatively and postoperatively. Significant improvements were found in physical examination and kinematic measures, which showed that children with CP and crouched gait who develop knee flexion contractures can be treated effectively using single-event multilevel surgery including a posterior knee capsulotomy or distal femoral extension osteotomy.

  5. Anterolateral Tenodesis or Anterolateral Ligament Complex Reconstruction: Effect of Flexion Angle at Graft Fixation When Combined With ACL Reconstruction.

    PubMed

    Inderhaug, Eivind; Stephen, Joanna M; Williams, Andy; Amis, Andrew A

    2017-09-01

    Despite numerous technical descriptions of anterolateral procedures, knowledge is limited regarding the effect of knee flexion angle during graft fixation. To determine the effect of knee flexion angle during graft fixation on tibiofemoral joint kinematics for a modified Lemaire tenodesis or an anterolateral ligament (ALL) complex reconstruction combined with anterior cruciate ligament (ACL) reconstruction. Controlled laboratory study. Twelve cadaveric knees were mounted in a test rig with kinematics recorded from 0° to 90° flexion. Loads applied to the tibia were 90-N anterior translation, 5-N·m internal tibial rotation, and combined 90-N anterior force and 5-N·m internal rotation. Intact, ACL-deficient, and combined ACL plus anterolateral-deficient states were tested, and then ACL reconstruction was performed and testing was repeated. Thereafter, modified Lemaire tenodeses and ALL procedures with graft fixation at 0°, 30°, and 60° of knee flexion and 20-N graft tension were performed combined with the ACL reconstruction, and repeat testing was performed throughout. Repeated-measures analysis of variance and Bonferroni-adjusted t tests were used for statistical analysis. In combined ACL and anterolateral deficiency, isolated ACL reconstruction left residual laxity for both anterior translation and internal rotation. Anterior translation was restored for all combinations of ACL and anterolateral procedures. The combined ACL reconstruction and ALL procedure restored intact knee kinematics when the graft was fixed in full extension, but when the graft was fixed in 30° and 60°, the combined procedure left residual laxity in internal rotation ( P = .043). The combined ACL reconstruction and modified Lemaire procedure restored internal rotation regardless of knee flexion angle at graft fixation. When the combined ACL reconstruction and lateral procedure states were compared with the ACL-only reconstructed state, a significant reduction in internal rotation

  6. The effect of a knee ankle foot orthosis incorporating an active knee mechanism on gait of a person with poliomyelitis.

    PubMed

    Arazpour, Mokhtar; Chitsazan, Ahmad; Bani, Monireh Ahmadi; Rouhi, Gholamreza; Ghomshe, Farhad Tabatabai; Hutchins, Stephen W

    2013-10-01

    The aim of this case study was to identify the effect of a powered stance control knee ankle foot orthosis on the kinematics and temporospatial parameters of walking by a person with poliomyelitis when compared to a knee ankle foot orthosis. A knee ankle foot orthosis was initially manufactured by incorporating drop lock knee joints and custom molded ankle foot orthoses and fitted to a person with poliomyelitis. The orthosis was then adapted by adding electrically activated powered knee joints to provide knee extension torque during stance and also flexion torque in swing phase. Lower limb kinematic and kinetic data plus data for temporospatial parameters were acquired from three test walks using each orthosis. Walking speed, step length, and vertical and horizontal displacement of the pelvis decreased when walking with the powered stance control knee ankle foot orthosis compared to the knee ankle foot orthosis. When using the powered stance control knee ankle foot orthosis, the knee flexion achieved during swing and also the overall pattern of walking more closely matched that of normal human walking. The reduced walking speed may have caused the smaller compensatory motions detected when the powered stance control knee ankle foot orthosis was used. The new powered SCKAFO facilitated controlled knee flexion and extension during ambulation for a volunteer poliomyelitis person.

  7. Prosthetic knee design by simulation

    SciTech Connect

    Hollerbach, K; Hollister, A

    1999-07-30

    Although 150,000 total knee replacement surgeries are performed annually in North America, current designs of knee prostheses have mechanical problems that include a limited range of motion, abnormal gait patterns, patellofemoral joint dysfunction, implant loosening or subsidence, and excessive wear. These problems fall into three categories: failure to reproduce normal joint kinematics, which results in altered limb function; bone-implant interface failure; and material failure. Modern computer technology can be used to design, prototype, and test new total knee implants. The design team uses the full range of CAD-CAM to design and produce implant prototypes for mechanical and clinical testing. Closer approximation of natural knee kinematics and kinetics is essential for improved patient function and diminished implant loads. Current knee replacement designs are based on 19th Century theories that the knee moves about a variable axis of rotation. Recent research has shown, however, that knee motion occurs about two fixed, offset axes of rotation. These aces are not perpendicular to the long axes of the bones or to each other, and the axes do not intersect. Bearing surfaces of mechanisms that move about axes of rotation are surfaces of revolution of those axes which advanced CAD technology can produce. Solids with surfaces of revolution for the two axes of rotation for the knee have been made using an HP9000 workstation and Structural Ideas Master Series CAD software at ArthroMotion. The implant's CAD model should closely replicate movements of the normal knee. The knee model will have a range of flexion-extension (FE) from -5 to 120 degrees. Movements include varus, valgus, internal and external rotation, as well as flexion and extension. The patellofemoral joint is aligned perpendicular to the FE axis and replicates the natural joint more closely than those of existing prostheses. The bearing surfaces will be more congruent than current designs and should

  8. Tibialis posterior tendon transfer corrects the foot drop component of cavovarus foot deformity in Charcot-Marie-Tooth disease.

    PubMed

    Dreher, T; Wolf, S I; Heitzmann, D; Fremd, C; Klotz, M C; Wenz, W

    2014-03-19

    The foot drop component of cavovarus foot deformity in patients with Charcot-Marie-Tooth disease is commonly treated by tendon transfer to provide substitute foot dorsiflexion or by tenodesis to prevent the foot from dropping. Our goals were to use three-dimensional foot analysis to evaluate the outcome of tibialis posterior tendon transfer to the dorsum of the foot and to investigate whether the transfer works as an active substitution or as a tenodesis. We prospectively studied fourteen patients with Charcot-Marie-Tooth disease and cavovarus foot deformity in whom twenty-three feet were treated with tibialis posterior tendon transfer to correct the foot drop component as part of a foot deformity correction procedure. Five patients underwent unilateral treatment and nine underwent bilateral treatment; only one foot was analyzed in each of the latter patients. Standardized clinical examinations and three-dimensional gait analysis with a special foot model (Heidelberg Foot Measurement Method) were performed before and at a mean of 28.8 months after surgery. The three-dimensional gait analysis revealed significant increases in tibiotalar and foot-tibia dorsiflexion during the swing phase after surgery. These increases were accompanied by a significant reduction in maximum plantar flexion at the stance-swing transition but without a reduction in active range of motion. Passive ankle dorsiflexion measured in knee flexion and extension increased significantly without any relevant decrease in passive plantar flexion. The AOFAS (American Orthopaedic Foot & Ankle Society) score improved significantly. Tibialis posterior tendon transfer was effective at correcting the foot drop component of cavovarus foot deformity in patients with Charcot-Marie-Tooth disease, with the transfer apparently working as an active substitution. Although passive plantar flexion was not limited after surgery, active plantar flexion at push-off was significantly reduced and it is unknown whether

  9. Bicompartmental individualized knee replacement : Use of patient-specific implants and instruments (iDuo™).

    PubMed

    Steinert, A F; Beckmann, J; Holzapfel, B M; Rudert, M; Arnholdt, J

    2017-02-01

    Bicompartmental knee replacement in patients with combined osteoarthritis (OA) of the medial or lateral and patellofemoral compartment. Patient-specific instruments and implants (ConforMIS iDuo™) with a planning protocol for optimal implant fit. Bicompartmental OA of the knee (Kellgren & Lawrence stage IV) affecting both the medial or lateral and patellofemoral compartment after unsuccessful conservative or joint-preserving surgery. Tricompartmental OA, knee ligament instabilities, knee deformities >15° (varus, valgus, extension deficit). Relative contraindication: body mass index >40; prior unicompartmental knee replacement or osteotomies. Midline or parapatellar medial skin incision, medial arthrotomy; identify mechanical contact zone of the intact femoral condyle (linea terminalis); remove remaining cartilage and all osteophytes that may interfere with the correct placement of the individually designed instruments. Balance knee in extension with patient-specific balancing chips. Resection of proximal tibia with an individual cutting block; confirm axial alignment using an extramedullary alignment guide, balance flexion gap using spacer blocks in 90° flexion. Final femur preparation with resection of the anterior trochlea. After balancing and identification of insert heights, final tibial preparation is performed. Implant is cemented in 45° of knee flexion. Remove excess cement and final irrigation, followed by closure. Sterile wound dressing; compressive bandage. No limitation of active/passive range of motion (ROM). Partial weight bearing the first 2 weeks, then transition to full weight bearing. Follow-up directly after surgery, at 12 and 52 weeks, then every 1-2 years. In all, 44 patients with bicompartmental OA of the medial and patellofemoral compartment were treated. Mean age 59 years. Minimum follow-up 12 months. Implant converted to TKA due to tibial loosening (1 patient); patella resurfacing (3 patients). No further revisions or

  10. Dynamic activity dependence of in vivo normal knee kinematics.

    PubMed

    Moro-oka, Taka-aki; Hamai, Satoshi; Miura, Hiromasa; Shimoto, Takeshi; Higaki, Hidehiko; Fregly, Benjamin J; Iwamoto, Yukihide; Banks, Scott A

    2008-04-01

    Dynamic knee kinematics were analyzed for normal knees in three activities, including two different types of maximum knee flexion. Continuous X-ray images of kneel, squat, and stair climb motions were taken using a large flat panel detector. CT-derived bone models were used for model registration-based 3D kinematic measurement. Three-dimensional joint kinematics and contact locations were determined using three methods: bone-fixed coordinate systems, interrogation of CT-based bone model surfaces, and interrogation of MR-based articular cartilage model surfaces. The femur exhibited gradual external rotation throughout the flexion range. Tibiofemoral contact exhibited external rotation, with contact locations translating posterior while maintaining 15 degrees to 20 degrees external rotation from 20 degrees to 80 degrees of flexion. From 80 degrees to maximum flexion, contact locations showed a medial pivot pattern. Kinematics based on bone-fixed coordinate systems differed from kinematics based on interrogation of CT and MR surfaces. Knee kinematics varied significantly by activity, especially in deep flexion. No posterior subluxation occurred for either femoral condyle in maximum knee flexion. Normal knees accommodate a range of motions during various activities while maintaining geometric joint congruency.

  11. A self-aligning knee joint for walking assistance devices.

    PubMed

    Byungjune Choi; Younbaek Lee; Jeonghun Kim; Minhyung Lee; Jongwon Lee; Se-Gon Roh; Hyundo Choi; Yong-Jae Kim; Jung-Yun Choi

    2016-08-01

    This paper presents a novel self-aligning knee mechanism for walking assistance devices for the elderly to provide physical gait assistance. Self-aligning knee joints can assist in flexion/extension motions of the knee joint and compensate the knee's transitional movements in the sagittal plane. In order to compensate the center of rotation, which moves with the flexion/extension motion of the human knee joint, a self-aligning knee joint is proposed that adds redundant degrees of freedom (i.e., 2-DoF) to the 1-DoF revolute joint. The key idea of the proposed mechanism is to decouple joint rotations and translations for use in lower-extremity wearable devices. This paper describes the mechanical design of this self-aligning knee mechanism and its implementation on a wearable robot and in preliminary experiments. The performance of the proposed mechanism is verified by simulations and experiments.

  12. Skin mounted accelerometer system for measuring knee range of motion.

    PubMed

    McGinnis, Ryan S; Patel, Shyamal; Silva, Ikaro; Mahadevan, Nikhil; DiCristofaro, Steve; Jortberg, Elise; Ceruolo, Melissa; Aranyosi, A J

    2016-08-01

    Sufficient range of motion of the knee joint is necessary for performing many activities of daily living. Ambulatory monitoring of knee function can provide valuable information about progression of diseases like knee osteoarthritis and recovery after surgical interventions like total knee arthroplasty. In this paper, we describe a skin-mounted, conformal, accelerometer-based system for measuring knee angle and range of motion that does not require a skilled operator to apply devices. We establish the accuracy of this technique with respect to clinical gold standard goniometric measurements on a dataset collected from normative subjects during the performance of repeated bouts of knee flexion and extension tests. Results show that knee angle and range of motion estimates are highly correlated with goniometer measurements, and track differences in knee angle and range of motion to within 1%. These results demonstrate the ability of this system to characterize knee angle and range of motion, enabling future longitudinal monitoring of knee motion in naturalistic environments.

  13. The biomechanics of the knee during the parachute landing fall.

    PubMed

    Henderson, J M; Hunter, S C; Berry, W J

    1993-12-01

    Because anterior knee pain syndrome is common in young paratroopers, we studied the role of the extensor mechanism in deceleration during the parachute landing fall (PLF) and the extent of knee flexion resulting from use of proper and variant landing styles. The subjects were novice paratroopers. Data were gathered by electromyography and by cinematography. At impact, a period of myoelectric silence was found that increased during training. Knee flexion angles varied from 130 degrees in the proper PLF to a low of 110 degrees in the toes-knees-nose PLF and to a high of 160 degrees in the hypergenuflexion PLF. The improper PLFs had a duration of deceleration shorter than that of a proper PLF, with maximal knee flexion occurring later in the landing act. Our results give direction to more specific lower-body training.

  14. Posterior cruciate ligament removal contributes to abnormal knee motion during posterior stabilized total knee arthroplasty.

    PubMed

    Cromie, Melinda J; Siston, Robert A; Giori, Nicholas J; Delp, Scott L

    2008-11-01

    Abnormal anterior translation of the femur on the tibia has been observed in mid flexion (20-60 degrees ) following posterior stabilized total knee arthroplasty. The underlying biomechanical causes of this abnormal motion remain unknown. The purpose of this study was to isolate the effects of posterior cruciate ligament removal on knee motion after total knee arthroplasty. We posed two questions: Does removing the posterior cruciate ligament introduce abnormal anterior femoral translation? Does implanting a posterior stabilized prosthesis change the kinematics from the cruciate deficient case? Using a navigation system, we measured passive knee kinematics of ten male osteoarthritic patients during surgery after initial exposure, after removing the anterior cruciate ligament, after removing the posterior cruciate ligament, and after implanting the prosthesis. Passively flexing and extending the knee, we calculated anterior femoral translation and the flexion angle at which femoral rollback began. Removing the posterior cruciate ligament doubled anterior translation (from 5.1 +/- 4.3 mm to 10.4 +/- 5.1 mm) and increased the flexion angle at which femoral rollback began (from 31.2 +/- 9.6 degrees to 49.3 +/- 7.3 degrees). Implanting the prosthesis increased the amount of anterior translation (to 16.1 +/- 4.4 mm), and did not change the flexion angle at which femoral rollback began. Abnormal anterior translation was observed in low and mid flexion (0-60 degrees) after removing the posterior cruciate ligament, and normal motion was not restored by the posterior stabilized prosthesis.

  15. The role of knee joint moments and knee impairments on self-reported knee pain during gait in patients with knee osteoarthritis.

    PubMed

    O'Connell, Megan; Farrokhi, Shawn; Fitzgerald, G Kelley

    2016-01-01

    The association between high mechanical knee joint loading during gait with onset and progression of knee osteoarthritis has been extensively studied. However, less attention has been given to risk factors related to increased pain during gait. The purpose of this study was to evaluate knee joint moments and clinical characteristics that may be associated with gait-related knee pain in patients with knee osteoarthritis. Sixty-seven participants with knee osteoarthritis were stratified into three groups of no pain (n=18), mild pain (n=27), or moderate/severe pain (n=22) based on their self-reported symptoms during gait. All participants underwent three-dimensional gait analysis. Quadriceps strength, knee extension range of motion, radiographic knee alignment and self-reported measures of global pain and function were also quantified. The moderate/severe pain group demonstrated worse global pain (P<0.01) and physical function scores (P<0.01) compared to the no pain and the mild pain groups. The moderate/severe pain group also walked with greater knee flexion moments during the midstance phase of gait compared to the no pain group (P=0.02). Additionally, the moderate/severe pain group demonstrated greater varus knee malalignment (P=0.009), which was associated with higher weight acceptance peak knee adduction moments (P=0.003) and worse global pain (P=0.003) and physical function scores (P=0.006). Greater knee flexion moment is present during the midstance phase of gait in patients with knee osteoarthritis and moderate/severe pain during gait. Additionally, greater varus malalignment may be a sign of increased global knee joint dysfunction that can influence many activities of daily living beyond gait. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Knee joint functional range of movement prior to and following total knee arthroplasty measured using flexible electrogoniometry.

    PubMed

    Myles, Christine M; Rowe, Philip J; Walker, Colin R C; Nutton, Richard W

    2002-08-01

    The functional ranges of movement of the knee were investigated in a group of patients with knee osteoarthritis (n = 42, mean age 70 years) before, 4 months and at 18-24 months after total knee arthroplasty and then compared with age matched normal subjects (n = 20, mean age 67 years). Flexible electrogoniometry was used to record the maximum flexion-extension angle, the minimum flexion-extension angle and flexion-extension excursions of both knees during eleven functional activities along with the active and passive knee joint range of motion measured using a manual goniometer. Over the eleven functional activities the patients pre-operatively exhibited 28% less knee joint excursion than normal age matched subjects. By 18-24 months following total knee arthroplasty only 2% of this deficit was recovered. Statistically this recovery was only significant in level walking, slope ascent and slope descent. A greater range of movement was measured in a non-weight bearing position than was used in weight bearing functional activity. It is concluded that total knee arthroplasty gives rise to little improvement in knee motion during functional activities and that functional range of movement of the knee remains limited when compared to normal knee function for a minimum of 18 months following operation.

  17. Multiple needle puncturing: balancing the varus knee.

    PubMed

    Bellemans, Johan

    2011-09-09

    The so-called "pie crusting" technique using multiple stab incisions is a well-established procedure for correcting tightness of the iliotibial band in the valgus knee. It is, however, not applicable for balancing the medial side in varus knees because of the risk for iatrogenic transsection of the medial collateral ligament (MCL). This article presents our experience with a safer alternative and minimally invasive technique for medial soft tissue balancing, where we make multiple punctures in the MCL using a 19-gauge needle to progressively stretch the MCL until a correct ligament balance is achieved. Our technique requires minimal to no additional soft tissue dissection and can even be performed percutaneously when necessary. This technique, therefore, does not impact the length of the skin or soft tissue incisions. We analyzed 61 cases with varus deformity that were intraoperatively treated using this technique. In 4 other cases, the technique was used as a percutaneous procedure to correct postoperative medial tightness that caused persistent pain on the medial side. The procedure was considered successful when a 2- to 4-mm mediolateral joint line opening was obtained in extension and 2 to 6 mm in flexion. In 62 cases (95%), a progressive correction of medial tightness was achieved according to the above-described criteria. Three cases were overreleased and required compensatory release of the lateral structures and use of a thicker insert. Based on these results, we consider needle puncturing an effective and safe technique for progressive correction of MCL tightness during minimally invasive total knee arthroplasty.

  18. Patient Self-Assessed Passive Range of Motion of the Knee Cannot Replace Health Professional Measurements.

    PubMed

    Borgbjerg, Jens; Madsen, Frank; Odgaard, Anders

    2017-03-01

    The purpose of this study was to investigate whether patients can accurately self-assess their knee passive range of motion (PROM). A picture-based questionnaire for patient self-assessment of knee PROM was developed and posted to patients. The self-assessed PROM from 58 patients was compared with surgeon-assessed PROM using a short-arm goniometer. Agreement between the measurement methods was calculated with the Bland-Altman method. We calculated the sensitivity and specificity of patient-assessed PROM in dichotomously detecting knee motion impairment in both flexion (≤ 100 degrees) and extension (≥ 10-degree flexion contracture). Surgeon- and patient-assessed knee PROM showed a mean difference (95% limits of agreement) of -2.1 degrees (-42.5 to 38.3 degrees) for flexion and -8.1 degrees (-28.8 to 12.7 degrees) for extension. The sensitivity of patient self-assessed PROM in identifying knee flexion and extension impairments was 86 and 100%, respectively, whereas its specificity was 84 and 43%, respectively. Although wide limits of agreement were observed between surgeon- and patient-assessed knee PROM, the picture-based questionnaire for patient assessment of knee ROM was found to be a valid tool for dichotomously detecting knee motion impairment in flexion (≤ 100 degrees). However, the specificity of the questionnaire for detection of knee extension impairments (≥ 10-degree flexion contracture) was low, which limits is practical utility for this purpose.

  19. Intraoperative joint gaps and mediolateral balance affect postoperative knee kinematics in posterior-stabilized total knee arthroplasty.

    PubMed

    Watanabe, Toshifumi; Muneta, Takeshi; Sekiya, Ichiro; Banks, Scott A

    2015-12-01

    Adjusting joint gaps and establishing mediolateral (ML) soft tissue balance are considered essential interventions for better outcomes in total knee arthroplasty (TKA). However, the relationship between intraoperative laxity measurements and weightbearing knee kinematics has not been well explored. This study aimed to quantify the effect of intraoperative joint gaps and ML soft tissue balance on postoperative knee kinematics in posterior-stabilized (PS)-TKA. We investigated 44 knees in 34 patients who underwent primary PS-TKA by a single surgeon. The central joint gaps and ML tilting angles at 0°, 10°, 30°, 60°, 90°, 120° and 135° flexion were measured during surgery. At a minimum of two year follow-up, we analyzed in vivo kinematics of these knees and examined the influence of intraoperative measurements on postoperative kinematics. Gap difference of knee flexion at 135° minus 0° was correlated with the total posterior translation of lateral femoral condyle (r=0.336, p=0.042) and femoral external rotation (r=0.488, p=0.002) during squatting, anteroposterior position of lateral femoral condyle (r=-0.510, p=0.001) and maximum knee flexion (r=0.355, p=0.031) in kneeling. Similar correlations were observed between deep flexion gap differences with respect to the 90° reference and postoperative knee kinematics. Well-balanced knees showed less anterior translation of medial femoral condyle in mid- to deep flexion, consistent femoral external rotation, and the most neutral valgus/varus rotation compared with unbalanced knees. These findings indicate the importance of adequate intraoperative joint gaps in deep flexion and ML soft tissue balance throughout the range of motion. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Ankle strength impairments associated with knee osteoarthritis.

    PubMed

    Gonçalves, Glaucia Helena; Sendín, Francisco Alburquerque; da Silva Serrão, Paula Regina Mendes; Selistre, Luiz Fernando Approbato; Petrella, Marina; Carvalho, Cristiano; Mattiello, Stela Márcia

    2017-07-01

    Knee Osteoarthritis seems to negatively impact ankle biomechanics. However, the effect of knee osteoarthritis on ankle muscle strength has not been clearly established. This study aimed to evaluate the ankle strength of the plantar flexors and dorsiflexors of patients with knee osteoarthritis in different degrees of severity. Thirty-seven patients with knee osteoarthritis and 15 controls, subjected to clinical and radiographic analysis, were divided into three groups: control, mild, and moderate knee osteoarthritis. Participants answered a self-reported questionnaire and accomplished a muscle torque assessment of the ankle using the Biodex dynamometer in isometric, concentric and eccentric modes. The mild osteoarthritis group (peak torque=26.85(SD 3.58)) was significantly weaker than the control (peak torque=41.75(SD 4.42)) in concentric plantar flexion (P<0.05). The control and mild osteoarthritis groups were not significantly different from the moderate osteoarthritis group (peak torque=36.12(SD 4.61)) in concentric plantar flexion. There were no significant differences for dorsiflexion among the groups; however the control and moderate osteoarthritis groups presented large and medium standardized mean differences. The mild osteoarthritis group was significantly lower than the control and moderate osteoarthritis groups in the concentric plantar flexion by concentric dorsiflexion torque ratio. Ankle function exhibited impairments in patients with knee osteoarthritis, especially in the plantar flexion torque, in which the mild osteoarthritis group was weaker than the control. Interestingly, patients with moderate knee osteoarthritis showed results similar to the control group in plantar flexion torque. The results raise the possibility of a compensatory mechanism of the plantar flexors developed by patients in more advanced degrees to balance other muscle failures. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Repositioning the knee joint in human body FE models using a graphics-based technique.

    PubMed

    Jani, Dhaval; Chawla, Anoop; Mukherjee, Sudipto; Goyal, Rahul; Vusirikala, Nataraju; Jayaraman, Suresh

    2012-01-01

    Human body finite element models (FE-HBMs) are available in standard occupant or pedestrian postures. There is a need to have FE-HBMs in the same posture as a crash victim or to be configured in varying postures. Developing FE models for all possible positions is not practically viable. The current work aims at obtaining a posture-specific human lower extremity model by reconfiguring an existing one. A graphics-based technique was developed to reposition the lower extremity of an FE-HBM by specifying the flexion-extension angle. Elements of the model were segregated into rigid (bones) and deformable components (soft tissues). The bones were rotated about the flexion-extension axis followed by rotation about the longitudinal axis to capture the twisting of the tibia. The desired knee joint movement was thus achieved. Geometric heuristics were then used to reposition the skin. A mapping defined over the space between bones and the skin was used to regenerate the soft tissues. Mesh smoothing was then done to augment mesh quality. The developed method permits control over the kinematics of the joint and maintains the initial mesh quality of the model. For some critical areas (in the joint vicinity) where element distortion is large, mesh smoothing is done to improve mesh quality. A method to reposition the knee joint of a human body FE model was developed. Repositions of a model from 9 degrees of flexion to 90 degrees of flexion in just a few seconds without subjective interventions was demonstrated. Because the mesh quality of the repositioned model was maintained to a predefined level (typically to the level of a well-made model in the initial configuration), the model was suitable for subsequent simulations.

  2. Associations of knee muscle force, bone malalignment, and knee-joint laxity with osteoarthritis in elderly people

    PubMed Central

    Nakagawa, Kazumasa; Maeda, Misako

    2017-01-01

    [Purpose] From the viewpoint of prevention of knee osteoarthritis, the aim of this study was to verify how muscle strength and joint laxity are related to knee osteoarthritis. [Subjects and Methods] The study subjects consisted of 90 community-dwelling elderly people aged more than 60 years (22 males, 68 females). Femorotibial angle alignment, knee joint laxity, knee extensors and flexor muscle strengths were measured in all subjects. In addition, the subjects were divided into four groups based on the presence of laxity and knee joint deformation, and the muscle strength values were compared. [Results] There was no significant difference in knee extensor muscle strength among the four groups. However, there was significant weakness of the knee flexor muscle in the group with deformation and laxity was compared with the group without deformation and laxity. [Conclusion] Decreased knee flexor muscle strengths may be involved in knee joint deformation. The importance of muscle strength balance was also considered. PMID:28356631

  3. Associations of knee muscle force, bone malalignment, and knee-joint laxity with osteoarthritis in elderly people.

    PubMed

    Nakagawa, Kazumasa; Maeda, Misako

    2017-03-01

    [Purpose] From the viewpoint of prevention of knee osteoarthritis, the aim of this study was to verify how muscle strength and joint laxity are related to knee osteoarthritis. [Subjects and Methods] The study subjects consisted of 90 community-dwelling elderly people aged more than 60 years (22 males, 68 females). Femorotibial angle alignment, knee joint laxity, knee extensors and flexor muscle strengths were measured in all subjects. In addition, the subjects were divided into four groups based on the presence of laxity and knee joint deformation, and the muscle strength values were compared. [Results] There was no significant difference in knee extensor muscle strength among the four groups. However, there was significant weakness of the knee flexor muscle in the group with deformation and laxity was compared with the group without deformation and laxity. [Conclusion] Decreased knee flexor muscle strengths may be involved in knee joint deformation. The importance of muscle strength balance was also considered.

  4. Effect of static neck flexion in cervical flexion-relaxation phenomenon in healthy males and females.

    PubMed

    Mousavi-Khatir, Roghayeh; Talebian, Saeed; Maroufi, Nader; Olyaei, Gholam Reza

    2016-04-01

    Neck pain is a common musculoskeletal disorder, especially among skilled workers who must keep their necks in a flexed position frequently during the day. The present study investigated changes in cervical flexion-relaxation phenomenon parameters after sustained neck flexion. The participants were 40 healthy subjects grouped by gender (20 females, 20 males). They were exposed to static neck flexion at the full angle of cervical flexion for 10 min. Each subject underwent three trials of cervical flexion and re-extension before and after this period. Differences in onset and cessation angle of flexion-relaxation phenomenon, maximum neck flexion angle, amplitude of neck muscle activation and flexion-relaxation ratio were evaluated. The maximum neck flexion angle significantly increased after sustained flexion. The onset of flexion-relaxation was significantly delayed during flexion, but cessation angle remained unchanged. Myoelectric activity of the cervical erector spinae muscles increased significantly after maintaining flexion, especially in female subjects. The flexion-relaxation ratio also decreased significantly. It was concluded that 10 min of static flexion results in a delay in flexion-relaxation phenomenon and a shortened silence period. Also the cervical erector spinae muscles are required to be active longer and generate more activity. These neuromuscular changes may be a risk factor for neck pain. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Post-traumatic knee stiffness: surgical techniques.

    PubMed

    Pujol, N; Boisrenoult, P; Beaufils, P

    2015-02-01

    Post-traumatic knee stiffness and loss of range of motion is a common complication of injuries to the knee area. The causes of post-traumatic knee stiffness can be divided into flexion contractures, extension contractures, and combined contractures. Post-traumatic stiffness can be due to the presence of dense intra-articular adhesions and/or fibrotic transformation of peri-articular structures. Various open and arthroscopic surgical treatments are possible. A precise diagnosis and understanding of the pathology is mandatory prior to any surgical treatment. Failure is imminent if all pathologies are not addressed correctly. From a general point of view, a flexion contracture is due to posterior adhesions and/or anterior impingement. On the other hand, extension contractures are due to anterior adhesions and/or posterior impingement. This overview will describe the different modern surgical techniques for treating post-traumatic knee stiffness. Any bony impingements must be treated before soft tissue release is performed. Intra-articular stiff knees with a loss of flexion can be treated by an anterior arthroscopic arthrolysis. Extra-articular pathology causing a flexion contracture can be treated by open or endoscopic quadriceps release. Extension contractures can be treated by arthroscopic or open posterior arthrolysis. Postoperative care (analgesia, rehabilitation) is essential to maintaining the range of motion obtained intra-operatively. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  6. Total Knee Arthroplasty in Hemophiliacs: Gains in Range of Motion Realized beyond Twelve Months Postoperatively

    PubMed Central

    Horneff, John G.; Forsyth, Angela; Nikci, Valdet; Nelson, Charles L.

    2012-01-01

    Background Hemophiliacs have extrinsic tightness from quadriceps and flexion contractures. We sought to examine the effect of a focused physical therapy regimen geared to hemophilic total knee arthroplasty. Methods Twenty-four knees undergoing intensive hemophiliac-specific physical therapy after total knee arthroplasty, at an average age of 46 years, were followed to an average 50 months. Results For all patients, flexion contracture improved from -10.5 degrees preoperatively to -5.1 degrees at final follow-up (p = 0.02). Knees with preoperative flexion less than 90 degrees were compared to knees with preoperative flexion greater than 90 degrees. Patients with preoperative flexion less than 90 degrees experienced improved flexion (p = 0.02), along with improved arc range of motion (ROM) and decreased flexion contracture. For those patients with specific twelve-month and final follow-up data points, there was a significant gain in flexion between twelve months and final follow-up (p = 0.02). Conclusions Hemophiliacs with the poorest flexion benefited most from focused quadriceps stretching to a more functional length, with gains not usually seen in the osteoarthritic population. This data may challenge traditional views that ROM gains are not expected beyond 12-18 months. PMID:22662297

  7. Tibiofemoral Instability After Primary Total Knee Arthroplasty: Posterior-Stabilized Implants for Obese Patients.

    PubMed

    Can, Ata; Erdogan, Fahri; Erdogan, Ayse Ovul

    2017-06-15

    Tibiofemoral instability is a common complication after total knee arthroplasty (TKA), accounting for up to 22% of all revision procedures. Instability is the second most common cause of revision in the first 5 years after primary TKA. In this study, 13 knees with tibiofemoral instability after TKA were identified among 693 consecutive primary TKA procedures. Patient demographics, body mass index, clinical symptoms, previous deformity, previous knee surgery, complications, interval between index TKA and first tibiofemoral instability, causes of instability, and interval between index TKA and revision TKA were retrospectively reviewed. Clinical outcomes were assessed with the Lysholm Knee Scoring Scale. All patients were women, and mean body mass index was 37.7 kg/m(2) (range, 27.2-52.6 kg/m(2)). Mean interval between index TKA and first tibiofemoral instability was 23.4 months (range, 9-45 months), and mean interval between index TKA and revision TKA was 25.6 months (range, 14-48 months). All patients had posterior cruciate ligament-retaining implants. Of the 13 knees, 11 had flexion instability and 2 had global instability. In all patients, instability was caused by incompetence of the posterior cruciate ligament; additionally, 1 patient had undersized and malpositioned implants. In 4 knees, the polyethylene insert was broken as well. All patients underwent revision TKA. Lysholm Knee Scoring Scale score had improved from a mean of 35.8 (range, 30-46) to a mean of 68.3 (range, 66-76). All patients included in this study were female and obese. The main cause of instability was secondary posterior cruciate ligament rupture and incompetence. The use of posterior-stabilized implants for primary TKA may prevent secondary instability in obese patients. [Orthopedics. 201x; xx(x):xx-xx.]. Copyright 2017, SLACK Incorporated.

  8. Changes in the activity of trunk and hip extensor muscles during bridge exercises with variations in unilateral knee joint angle.

    PubMed

    Kim, Juseung; Park, Minchul

    2016-09-01

    [Purpose] This study compared abdominal and hip extensor muscle activity during a bridge exercise with various knee joint angles. [Subjects and Methods] Twenty-two healthy male subjects performed a bridge exercise in which the knee joint angle was altered. While subjects performed the bridge exercise, external oblique, internal oblique, gluteus maximus, and semitendinosus muscle activity was measured using electromyography. [Results] The bilateral external and internal oblique muscle activity was significantly higher at 0° knee flexion compared to 120°, 90°, and 60°. The bilateral gluteus maximus muscle activity was significantly different at 0° of knee flexion compared to 120°, 90°, and 60°. The ipsilateral semitendinosus muscle activity was significantly increased at 90° and 60° of knee flexion compared to 120°, and significantly decreased at 0° knee flexion compared with 120°, 90°, and 60°. The contralateral semitendinosus muscle activity was significantly higher at 60° of knee flexion than at 120°, and significantly higher at 0° of knee flexion than at 120°, 90°, and 60°. [Conclusion] Bridge exercises performed with knee flexion less than 90° may be used to train the ipsilateral semitendinosus. Furthermore, bridge exercise performed with one leg may be used to train abdominal and hip extensor muscles.

  9. Changes in the activity of trunk and hip extensor muscles during bridge exercises with variations in unilateral knee joint angle

    PubMed Central

    Kim, Juseung; Park, Minchul

    2016-01-01

    [Purpose] This study compared abdominal and hip extensor muscle activity during a bridge exercise with various knee joint angles. [Subjects and Methods] Twenty-two healthy male subjects performed a bridge exercise in which the knee joint angle was altered. While subjects performed the bridge exercise, external oblique, internal oblique, gluteus maximus, and semitendinosus muscle activity was measured using electromyography. [Results] The bilateral external and internal oblique muscle activity was significantly higher at 0° knee flexion compared to 120°, 90°, and 60°. The bilateral gluteus maximus muscle activity was significantly different at 0° of knee flexion compared to 120°, 90°, and 60°. The ipsilateral semitendinosus muscle activity was significantly increased at 90° and 60° of knee flexion compared to 120°, and significantly decreased at 0° knee flexion compared with 120°, 90°, and 60°. The contralateral semitendinosus muscle activity was significantly higher at 60° of knee flexion than at 120°, and significantly higher at 0° of knee flexion than at 120°, 90°, and 60°. [Conclusion] Bridge exercises performed with knee flexion less than 90° may be used to train the ipsilateral semitendinosus. Furthermore, bridge exercise performed with one leg may be used to train abdominal and hip extensor muscles. PMID:27799688

  10. Treatable Bedridden Elderly―Recovery from Flexion Contracture after Cortisol Replacement in a Patient with Isolated Adrenocorticotropic Hormone Deficiency

    PubMed Central

    Tanaka, Takamasa; Terada, Norihiko; Fujikawa, Yoshiki; Fujimoto, Takushi

    2016-01-01

    Isolated adrenocorticotropic hormone deficiency (IAD) is a rare disorder with diverse clinical presentations. A 79-year-old man was bedridden for six months due to flexion contractures of the bilateral hips and knees, along with hyponatremia. He was diagnosed with IAD based on the results of endocrine tests. After one month of corticosteroid replacement, he recovered and was able to stand up by himself. Although flexion contracture is a rare symptom of IAD, steroid replacement therapy may be effective, even for seemingly irreversibly bedridden elderly patients. In bedridden elderly patients with flexion contractures, we should consider and look for any signs of adrenal insufficiency. PMID:27746435

  11. Treatable Bedridden Elderly -Recovery from Flexion Contracture after Cortisol Replacement in a Patient with Isolated Adrenocorticotropic Hormone Deficiency.

    PubMed

    Tanaka, Takamasa; Terada, Norihiko; Fujikawa, Yoshiki; Fujimoto, Takushi

    Isolated adrenocorticotropic hormone deficiency (IAD) is a rare disorder with diverse clinical presentations. A 79-year-old man was bedridden for six months due to flexion contractures of the bilateral hips and knees, along with hyponatremia. He was diagnosed with IAD based on the results of endocrine tests. After one month of corticosteroid replacement, he recovered and was able to stand up by himself. Although flexion contracture is a rare symptom of IAD, steroid replacement therapy may be effective, even for seemingly irreversibly bedridden elderly patients. In bedridden elderly patients with flexion contractures, we should consider and look for any signs of adrenal insufficiency.

  12. [Correlation analysis on the disorders of patella-femoral joint and torsional deformity of tibia].

    PubMed

    Sun, Zhen-Jie; Yuan, Yi; Liu, Rui-Bo

    2015-03-01

    To reveal the possible mechanism involved in patella-femoral degenerative arthritis (PFDA) in- duced by torsion-deformity of tibia via analyzing the relationship between torsion-deformity of the tibia in patients with PFDA and the disorder of patella-femoral joint under the static and dynamic conditions. From October 2009 to October 2010, 50 patients (86 knees, 24 knees of male patients and 62 knees of female patients) with PFDA were classified as disease group and 16 people (23 knees, 7 knees of males and 16 knees of females) in the control group. The follow indexes were measured: the torsion-angle of tibia on CT scanning imagings, the patella-femoral congruence angle and lateral patella-femoral angle under static and dynamic conditions when the knee bent at 30 degrees of flexion. Based on the measurement results, the relationship between the torsion-deformity of tibias and the disorders of patella-femoral joints in patients with PFDA were analyzed. Finally,the patients were divided into three groups including large torsion-angle group, small torsion-angle group and normal group according to the size of torsion-angle, in order to analyze the relationship between torsion-deformity and disorders of patella-femoral joint, especially under the dynamic conditions. Compared with patients without PFDA, the ones with PFDA had bigger torsion-angle (30.30 ± 7.11)° of tibia, larger patella-femoral congruence angle (13.20 ± 3.94)° and smaller lateral patella-femoral angle (12.30 ± 3.04)°. The congruence angle and lateral patella-femoral angle under static and dynamic conditions had statistical differences respectively in both too-big torsion-angle group and too-small torsion-angle group. The congruence angle and lateral patella-femoral angle under static and dynamic conditions had no statistical differences in normal torsion-angle group. Torsion-deformity of tibia is the main reason for disorder of patella-femoral joint in the patients with PFDA. Torsion-deformity of

  13. The influence of knee position on ankle dorsiflexion - a biometric study

    PubMed Central

    2014-01-01

    Background Musculus gastrocnemius tightness (MGT) can be diagnosed by comparing ankle dorsiflexion (ADF) with the knee extended and flexed. Although various measurement techniques exist, the degree of knee flexion needed to eliminate the effect of the gastrocnemius on ADF is still unknown. The aim of this study was to identify the minimal degree of knee flexion required to eliminate the restricting effect of the musculus gastrocnemius on ADF. Methods Bilateral ADF of 20 asymptomatic volunteers aged 18-40 years (50% female) was assessed prospectively at six different degrees of knee flexion (0°, 20°, 30°, 45°, 60°, 75°, Lunge). Tests were performed following a standardized protocol, non weightbearing and weightbearing, by two observers. Statistics comprised of descriptive statistics, t-tests, repeated measurement ANOVA and ICC. Results 20 individuals with a mean age of 27 ± 4 years were tested. No significant side to side differences were observed. The average ADF [95% confidence interval] for non weightbearing was 4° [1°-8°] with the knee extended and 20° [16°-24°] for the knee 75° flexed. Mean weightbearing ADF was 25° [22°-28°] for the knee extended and 39° [36°-42°] for the knee 75° flexed. The mean differences between 20° knee flexion and full extension were 15° [12°-18°] non weightbearing and 13° [11°-16°] weightbearing. Significant differences of ADF were only found between full extension and 20° of knee flexion. Further knee flexion did not increase ADF. Conclusion Knee flexion of 20° fully eliminates the ADF restraining effect of the gastrocnemius. This knowledge is essential to design a standardized clinical examination assessing MGT. PMID:25053374

  14. Kinematic Analysis of a Posterior-stabilized Knee Prosthesis

    PubMed Central

    Zhao, Zhi-Xin; Wen, Liang; Qu, Tie-Bing; Hou, Li-Li; Xiang, Dong; Bin, Jia

    2015-01-01

    Background: The goal of total knee arthroplasty (TKA) is to restore knee kinematics. Knee prosthesis design plays a very important role in successful restoration. Here, kinematics models of normal and prosthetic knees were created and validated using previously published data. Methods: Computed tomography and magnetic resonance imaging scans of a healthy, anticorrosive female cadaver were used to establish a model of the entire lower limbs, including the femur, tibia, patella, fibula, distal femur cartilage, and medial and lateral menisci, as well as the anterior cruciate, posterior cruciate, medial collateral, and lateral collateral ligaments. The data from the three-dimensional models of the normal knee joint and a posterior-stabilized (PS) knee prosthesis were imported into finite element analysis software to create the final kinematic model of the TKA prosthesis, which was then validated by comparison with a previous study. The displacement of the medial/lateral femur and the internal rotation angle of the tibia were analyzed during 0–135° flexion. Results: Both the output data trends and the measured values derived from the normal knee's kinematics model were very close to the results reported in a previous in vivo study, suggesting that this model can be used for further analyses. The PS knee prosthesis underwent an abnormal forward displacement compared with the normal knee and has insufficient, or insufficiently aggressive, “rollback” compared with the lateral femur of the normal knee. In addition, a certain degree of reverse rotation occurs during flexion of the PS knee prosthesis. Conclusions: There were still several differences between the kinematics of the PS knee prosthesis and a normal knee, suggesting room for improving the design of the PS knee prosthesis. The abnormal kinematics during early flexion shows that the design of the articular surface played a vital role in improving the kinematics of the PS knee prosthesis. PMID:25591565

  15. Squat exercise to estimate knee megaprosthesis rehabilitation: a pilot study.

    PubMed

    Lovecchio, Nicola; Zago, Matteo; Sciumè, Luciana; Lopresti, Maurizio; Sforza, Chiarella

    2015-07-01

    [Purpose] This study evaluated a specific rehabilitation protocol using a half squat after total knee reconstruction with distal femur megaprosthesis and tibial allograft-prosthesis composite. [Subject and Methods] Squat execution was recorded by a three-dimensional system before and after a specific rehabilitation program on a 28-year-old patient. Squat duration, body center of mass trajectory, and vertical range of motion were determined. Step width and joint angles and symmetry (hip flexion, extension, and rotation, knee flexion, and ankle dorsal and plantar flexion) were estimated. Knee and hip joint symmetry was computed using a bilateral cyclogram technique. [Results] After rehabilitation, the squat duration was longer (75%), step width was similar, and vertical displacement was higher. Hip flexion increased by over 20%, and ankle dorsiflexion diminished by 14%. The knee had the highest symmetry gain (4.1-3.4%). Angle-angle plot subtended areas decreased from 108° to 40°(2) (hip) and from 204° to 85°(2) (knee), showing improvement in movement symmetry. [Conclusion] We concluded that the squat is an effective multifactorial exercise to estimate rehabilitation outcomes after megaprosthesis, also considering that compressive and shear forces are minimal up to 60-70° of knee flexion.

  16. Squat exercise to estimate knee megaprosthesis rehabilitation: a pilot study

    PubMed Central

    Lovecchio, Nicola; Zago, Matteo; Sciumè, Luciana; Lopresti, Maurizio; Sforza, Chiarella

    2015-01-01

    [Purpose] This study evaluated a specific rehabilitation protocol using a half squat after total knee reconstruction with distal femur megaprosthesis and tibial allograft-prosthesis composite. [Subject and Methods] Squat execution was recorded by a three-dimensional system before and after a specific rehabilitation program on a 28-year-old patient. Squat duration, body center of mass trajectory, and vertical range of motion were determined. Step width and joint angles and symmetry (hip flexion, extension, and rotation, knee flexion, and ankle dorsal and plantar flexion) were estimated. Knee and hip joint symmetry was computed using a bilateral cyclogram technique. [Results] After rehabilitation, the squat duration was longer (75%), step width was similar, and vertical displacement was higher. Hip flexion increased by over 20%, and ankle dorsiflexion diminished by 14%. The knee had the highest symmetry gain (4.1–3.4%). Angle-angle plot subtended areas decreased from 108° to 40°2 (hip) and from 204° to 85°2 (knee), showing improvement in movement symmetry. [Conclusion] We concluded that the squat is an effective multifactorial exercise to estimate rehabilitation outcomes after megaprosthesis, also considering that compressive and shear forces are minimal up to 60–70° of knee flexion. PMID:26311992

  17. The effect of trunk flexion on able-bodied gait.

    PubMed

    Saha, Devjani; Gard, Steven; Fatone, Stefania

    2008-05-01

    This study examined the effect of sagittal trunk posture on the gait of able-bodied subjects. Understanding the effect of trunk posture on gait is of clinical interest since alterations in trunk posture often occur with age or in the presence of spinal pathologies, such as lumbar flatback. Gait analysis was conducted on 14 adults walking at self-selected slow, normal, and fast walking speeds while maintaining three trunk postures: upright, and with 25+/-7 degrees and 50+/-7 degrees of trunk flexion from the vertical. During trunk-flexed gait, subjects adopted a crouch posture characterized by sustained knee flexion during stance and an increase in ankle dorsiflexion and hip flexion angles. During stance, these kinematic adaptations produced a posterior shift in the positions of the trunk and pelvis, which helped to offset the anterior shift in the trunk mass that occurred with trunk flexion. In this way, kinematic adaptations may have been used to maintain balance by shifting the body's center of mass to a position similar to that of upright walking. These changes in lower limb joint kinematics created a phase lag in the position of the hip joint center relative to that of the ankle joint center in the sagittal plane. Alterations in the sagittal alignment of the hip and ankle joint positions were associated with a phase lag in the vertical position, velocity, and acceleration of the body's center of mass (BCOM) relative to upright walking. Since the vertical ground reaction force (GRF(v)) is proportional to the vertical acceleration of the BCOM, significant changes were also seen in the GRF(v) during trunk-flexed gait. In summary, kinematic adaptations necessary to maintain dynamic balance altered the trajectory and acceleration of the BCOM in the vertical direction, which was reflected in the GRF(v). The results of this study may help clinicians better understand the nature and impact of compensatory mechanisms in patients who exhibit trunk-flexed postures during

  18. Primary and coupled motions of the native knee in response to applied varus and valgus load.

    PubMed

    Gladnick, Brian P; Boorman-Padgett, James; Stone, Kyle; Kent, Robert N; Cross, Michael B; Mayman, David J; Pearle, Andrew D; Imhauser, Carl W

    2016-06-01

    Knowledge of the complex kinematics of the native knee is a prerequisite for a successful reconstructive procedure. The aim of this study is to describe the primary and coupled motions of the native knee throughout the range of knee flexion, in response to applied varus and valgus loads. Twenty fresh-frozen cadaver knees were affixed to a six degree of freedom robotic arm with a universal force-moment sensor, and loaded with a 4Nm moment in varus and valgus at 0, 15, 30, 45, and 90° of knee flexion. The resulting tibiofemoral angulation, displacement, and rotation were recorded. For each parameter investigated, the knee joint demonstrated more laxity at higher flexion angles. Varus angulation increased progressively from zero (2.0° varus) to 90 (5.2° varus) degrees of knee flexion (p<0.001). Valgus angulation also increased progressively, from zero (1.5° valgus) to 90 (3.9° valgus) degrees of knee flexion (p<0.001). At all flexion angles, the magnitude of tibiofemoral angle deviation was larger with varus than with valgus loading (p<0.05). We conclude that the native knee exhibits small increases in coronal plane laxity as the flexion angle increases, and that the knee has generally more laxity under varus load than with valgus load throughout the Range of Motion (ROM). Larger differences in laxity of more than 2 to 3°, or peak laxity specifically during the range of mid-flexion, were not found in our cadaver model and are not likely to represent normal coronal plane kinematics. Level V, biomechanical cadaveric study. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. In Vivo Kinematics of the Anterior Cruciate Ligament Deficient Knee During Wide-Based Squat Using a 2D/3D Registration Technique.

    PubMed

    Miyaji, Takeshi; Gamada, Kazuyoshi; Kidera, Kenichi; Ikuta, Futoshi; Yoneta, Kei; Shindo, Hiroyuki; Osaki, Makoto; Yonekura, Akihiko

    2012-01-01

    Anterior cruciate ligament (ACL) deficiency increases the risk of early osteoarthritis (OA). Studies of ACL deficient knee kinematics would be important to reveal the disease process and therefore to find mechanisms which would potentially slow OA progression. The purpose of this study was to determine if in vivo kinematics of the anterior cruciate ligament deficient (ACLD) knee during a wide-based squat activity differ from kinematics of the contralateral intact knee. Thirty-three patients with a unilateral ACLD knee consented to participate in this institutional review board approved study with the contralateral intact knee serving as the control. In vivo knee kinematics during the wide-based squat were analyzed using a 2D/3D registration technique utilizing CT-based bone models and lateral fluoroscopy. Comparisons were performed using values between 0 and 100° flexion both in flexion and extension phases of the squat activity. Both the ACLD and intact knees demonstrated increasing tibial internal rotation with knee flexion, and no difference was observed in tibial rotation between the groups. The tibia in the ACLD knee was more anterior than that of the contralateral knees at 0 and 5° flexion in both phases (p < 0.05). Tibiofemoral medial contact points of the ACLD knees were more posterior than that of the contralateral knees at 5, 10 and 15° of knee flexion in the extension phase of the squat activity (p < 0.05). Tibiofemoral lateral contact points of the ACLD knees were more posterior than that of the contralateral knees at 0° flexion in the both phases (p < 0.05). The kinematics of the ACLD and contralateral intact knees were similar during the wide-based squat except at the low flexion angles. Therefore, we conclude the wide-based squat may be recommended for the ACLD knee by avoiding terminal extension.

  20. The effects of knee direction, physical activity and age on knee joint position sense.

    PubMed

    Relph, Nicola; Herrington, Lee

    2016-06-01

    Previous research has suggested a decline in knee proprioception with age. Furthermore, regular participation in physical activity may improve proprioceptive ability. However, there is no large scale data on uninjured populations to confirm these theories. The aim of this study was to provide normative knee joint position data (JPS) from healthy participants aged 18-82years to evaluate the effects of age, physical activity and knee direction. A sample of 116 participants across five age groups was used. The main outcome measures were knee JPS absolute error scores into flexion and extension, Tegner activity levels and General Practitioner Physical Activity Questionnaire results. Absolute error scores in to knee flexion were 3.6°, 3.9°, 3.5°, 3.7° and 3.1° and knee extension were 2.7°, 2.5°, 2.9°, 3.4° and 3.9° for ages 15-29, 30-44, 45-59, 60-74 and 75 years old respectively. Knee extension and flexion absolute error scores were significantly different when age group data were pooled. There was a significant effect of age and activity level on joint position sense into knee extension. Age and lower Tegner scores were also negatively correlated to joint position sense into knee extension. The results provide some evidence for a decline in knee joint position sense with age. Further, active populations may have heightened static proprioception compared to inactive groups. Normative knee joint position sense data is provided and may be used by practitioners to identify patients with reduced proprioceptive ability. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Estimating the probability of radiographic osteoarthritis in the older patient with knee pain.

    PubMed

    Peat, George; Thomas, Elaine; Duncan, Rachel; Wood, Laurence; Wilkie, Ross; Hill, Jonathan; Hay, Elaine M; Croft, Peter

    2007-06-15

    To determine whether clinical information can practically rule in or rule out the presence of radiographic osteoarthritis in older adults with knee pain. We conducted a cross-sectional diagnostic study involving 695 adults ages >/=50 years reporting knee pain within the last year identified by postal survey and attending a research clinic. Potential indicators of radiographic osteoarthritis were gathered by self-complete questionnaires, clinical interview, and physical examination. Participants underwent plain radiography (posteroanterior, skyline, and lateral views). Radiographic osteoarthritis was defined as the presence of definite osteophytes in at least 1 joint compartment of the index knee. Independent predictors of radiographic osteoarthritis were age, sex, body mass index, absence of whole leg pain, traumatic onset, difficulty descending stairs, palpable effusion, fixed-flexion deformity, restricted-flexion range of motion, and crepitus. Using this model, 245 participants had a predicted probability >/=80% (practical rule in), of whom 231 (94%) actually had radiographic osteoarthritis (specificity 93%). Twenty-one participants had a predicted probability <20% (practical rule out), of whom only 2 (10%) had radiographic osteoarthritis (sensitivity 99.6%). The predicted probability of radiographic osteoarthritis for the remaining 429 participants fell into an intermediate category (20-79%). Simple clinical information can be used to estimate the probability of radiographic osteoarthritis in individual patients. However, for the majority of community-dwelling older adults with knee pain this method enables the presence of radiographic osteoarthritis to be neither confidently ruled in nor ruled out. Prospective validation and updating of these findings in an independent sample is required.

  2. Custom rotating hinge total knee arthroplasty in patients with poliomyelitis affected limbs.

    PubMed

    Rahman, Jeeshan; Hanna, Sammy A; Kayani, Babar; Miles, Jonathan; Pollock, Robin C; Skinner, John A; Briggs, Timothy W; Carrington, Richard W

    2015-05-01

    Total knee arthroplasty (TKA) in limbs affected by poliomyelitis is a technically challenging procedure. These patients often demonstrate acquired articular and metaphyseal angular deformities, bone loss, narrowness of the intramedullary canals, impaired quadriceps strength, flexion contractures and ligamentous laxity producing painful hyperextension. Thus, using condylar knee designs in these patients will likely result in early failure because of instability and abnormal load distribution. The aim of this study was to assess the outcomes associated with use of the customised (SMILES) rotating-hinge knee system at our institution for TKA in poliomyelitis-affected limbs. We retrospectively reviewed the outcome of 14 TKAs using the (SMILES) prosthesis in 13 patients with limbs affected by poliomyelitis. All patients had painful unstable knees with hyperextension. There were ten females and three males with a mean age of 66 years (range 51-84) at time of surgery. Patients were followed up clinically, radiologically and functionally with the Oxford knee score (OKS). Mean follow-up was 72 months (16-156). There were no immediate or early complications. One patient fell and sustained a peri-prosthetic fracture at seven months requiring revision to a longer stem. Radiological evaluation showed satisfactory alignment with no signs of loosening in all cases. Mean OKS improved from 11.6 (4-18) to 31.5 (18-40) postoperatively (p < 0.001). The rotating hinge (SMILES) prosthesis is effective at relieving pain and improving function in patients with poliomyelitis. The device compensates well for ligamentous insufficiency as well as for any associated bony deformity.

  3. Knee Bursitis

    MedlinePlus

    ... make a diagnosis of knee bursitis during a physical exam. Your doctor will inspect your knee by: Comparing the condition of both knees, particularly if only one is painful Gently pressing on different areas of your knee to detect warmth, swelling and the source of pain Carefully moving ...

  4. Estimation of ACL forces by reproducing knee kinematics between sets of knees: A novel non-invasive methodology.

    PubMed

    Darcy, Shon P; Kilger, Robert H P; Woo, Savio L-Y; Debski, Richard E

    2006-01-01

    In situ force in the anterior cruciate ligament (ACL) has been quantified both in vitro in response to relatively simple loads by means of robotic technology, as well as in vivo in response to more complex loads by means of force transducers and computational models. However, a methodology has been suggested to indirectly estimate the in situ forces in the ACL in a non-invasive, non-contact manner by reproducing six-degree of freedom (six-DOF) in vivo kinematics on cadaveric knees using a robotic/UFS testing system. Therefore, the objective of this study was to determine the feasibility of this approach. Kinematics from eight porcine knees (source knees) were collected at 30 degrees , 60 degrees , and 90 degrees of flexion in response to: (1) an anterior load of 100 N and (2) a valgus load of 5 N m. The average of each kinematic data set was reproduced on a separate set of eight knees (target knees). The in situ forces in the ACL were determined for both sets of knees and compared. Significant differences (rho<0.05) were found between the source knees and the target knees for all flexion angles in response to an anterior load. However, in response to valgus loads, there was no significant difference between the source knees and the target knees at 30 degrees and 90 degrees of flexion. It was noted that there was a correlation between anterior knee laxity (the distance along the displacement axis from the origin to the beginning of the linear region of the load-displacement curve) and internal-external rotation. These data suggest that in order to obtain reproducible results one needs to first match knees to knees with comparable anterior knee laxity. Thus, an estimate of the in situ forces in the ACL during in vivo activities might be obtainable using this novel methodology.

  5. Fatigue Effects on Knee Joint Stability During Two Jump Tasks in Women

    PubMed Central

    Ortiz, Alexis; Olson, Sharon L.; Etnyre, Bruce; Trudelle-Jackson, Elaine E.; Bartlett, William; Venegas-Rios, Heidi L.

    2010-01-01

    Dynamic knee joint stability may be affected by the onset of metabolic fatigue during sports participation that could increase the risk for knee injury. The purpose of this investigation was to determine the effects of metabolic fatigue on knee muscle activation, peak knee joint angles, and peak knee internal moments in young women during 2 jumping tasks. Fifteen women (mean age: 24.6 ± 2.6 years) participated in one nonfatigued session and one fatigued session. During both sessions, peak knee landing flexion and valgus joint angles, peak knee extension and varus/valgus internal moments, electromyographic (EMG) muscle activity of the quadriceps and hamstrings, and quadriceps/hamstring EMG cocontraction ratio were measured. The tasks consisted of a single-legged drop jump from a 40-cm box and a 20-cm, up-down, repeated hop task. The fatigued session included a Wingate anaerobic protocol followed by performance of the 2 tasks. Although participants exhibited greater knee injury–predisposing factors during the fatigued session, such as lesser knee flexion joint angles, greater knee valgus joint angles, and greater varus/valgus internal joint moments for both tasks, only knee flexion during the up-down task was statistically significant (p = 0.028). Metabolic fatigue may perhaps predispose young women to knee injuries by impairing dynamic knee joint stability. Training strength-endurance components and the ability to maintain control of body movements in either rested or fatigued situations might help reduce injuries in young women athletes. PMID:20300024

  6. Fatigue effects on knee joint stability during two jump tasks in women.

    PubMed

    Ortiz, Alexis; Olson, Sharon L; Etnyre, Bruce; Trudelle-Jackson, Elaine E; Bartlett, William; Venegas-Rios, Heidi L

    2010-04-01

    Dynamic knee joint stability may be affected by the onset of metabolic fatigue during sports participation that could increase the risk for knee injury. The purpose of this investigation was to determine the effects of metabolic fatigue on knee muscle activation, peak knee joint angles, and peak knee internal moments in young women during 2 jumping tasks. Fifteen women (mean age: 24.6 +/- 2.6 years) participated in one nonfatigued session and one fatigued session. During both sessions, peak knee landing flexion and valgus joint angles, peak knee extension and varus/valgus internal moments, electromyographic (EMG) muscle activity of the quadriceps and hamstrings, and quadriceps/hamstring EMG cocontraction ratio were measured. The tasks consisted of a single-legged drop jump from a 40-cm box and a 20-cm, up-down, repeated hop task. The fatigued session included a Wingate anaerobic protocol followed by performance of the 2 tasks. Although participants exhibited greater knee injury-predisposing factors during the fatigued session, such as lesser knee flexion joint angles, greater knee valgus joint angles, and greater varus/valgus internal joint moments for both tasks, only knee flexion during the up-down task was statistically significant (p = 0.028). Metabolic fatigue may perhaps predispose young women to knee injuries by impairing dynamic knee joint stability. Training strength-endurance components and the ability to maintain control of body movements in either rested or fatigued situations might help reduce injuries in young women athletes.

  7. Knee rotation influences the femoral tunnel angle measurement after anterior cruciate ligament reconstruction: a 3-dimensional computed tomography model study.

    PubMed

    Tang, Jing; Thorhauer, Eric; Marsh, Chelsea; Fu, Freddie H; Tashman, Scott

    2014-07-01

    Femoral tunnel angle (FTA) has been proposed as a metric for evaluating whether ACL reconstruction was performed anatomically. In clinic, radiographic images are typically acquired with an uncertain amount of internal/external knee rotation. The extent to which knee rotation will influence FTA measurement is unclear. Furthermore, differences in FTA measurement between the two common positions (0° and 45° knee flexion) have not been established. The purpose of this study was to investigate the influence of knee rotation on FTA measurement after ACL reconstruction. Knee CT data from 16 subjects were segmented to produce 3D bone models. Central axes of tunnels were identified. The 0° and 45° flexion angles were simulated. Knee internal/external rotations were simulated in a range of ± 20°. FTA was defined as the angle between the tunnel axis and femoral shaft axis, orthogonally projected into the coronal plane. Femoral tunnel angle was positively/negatively correlated with knee rotation angle at 0°/45° knee flexion. At 0° knee flexion, FTA for anterio-medial (AM) tunnels was significantly decreased at 20° of external knee rotation. At 45° knee flexion, more than 16° external or 19° internal rotation significantly altered FTA measurements for single-bundle tunnels; smaller rotations (± 9° for AM, ± 5° for PL) created significant errors in FTA measurements after double-bundle reconstruction. Femoral tunnel angle measurements were correlated with knee rotation. Relatively small imaging malalignment introduced significant errors with knee flexed 45°. This study supports using the 0° flexion position for knee radiographs to reduce errors in FTA measurement due to knee internal/external rotation.

  8. 3D intersegmental knee loading in below-knee amputees across steady-state walking speeds.

    PubMed

    Fey, Nicholas P; Neptune, Richard R

    2012-05-01

    Unilateral below-knee amputees often develop comorbidities that include knee joint disorders (e.g., intact leg knee osteoarthritis), with the mechanisms leading to these comorbidities being poorly understood. Mechanical knee loading of non-amputees has been associated with joint disorders and shown to be influenced by walking speed. However, the relationships between amputee knee loading and speed have not been identified. This study examined three-dimensional mechanical knee loading of amputees across a wide range of steady-state walking speeds. Fourteen amputees and 10 non-amputee control subjects were analyzed at four overground walking speeds. At each speed, intersegmental joint moment and force impulses (i.e., time-integrals over the stance phase) were compared between the control, intact and residual knees using repeated-measures ANOVAs. There were no differences in joint force impulses between the intact and control knees. The intact knee abduction moment impulse was lower than the non-amputees at 0.6 and 0.9 m/s. The intact knee flexion moment impulses at 0.6, 1.2 and 1.5m/s and knee external rotation moment impulses at all speeds were greater than the residual knee. The residual knee extension moment and posterior force impulses were insensitive to speed increases, while these quantities increased in intact and control knees. These results suggest the intact knees of asymptomatic and relatively new amputees are not overloaded during walking compared to non-amputees. Increased knee loads may develop in response to prolonged prosthesis usage or joint disorder onset. Further study is needed to determine if the identified bilateral loading asymmetries across speeds lead to diminished knee joint health. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. The relationship between external knee moments and muscle co-activation in subjects with medial knee osteoarthritis.

    PubMed

    Selistre, Luiz Fernando Approbato; Mattiello, Stela Márcia; Nakagawa, Theresa Helissa; Gonçalves, Glaucia Helena; Petrella, Marina; Jones, Richard Keith

    2017-04-01

    External knee moments are reliable to measure knee load but it does not take into account muscle activity. Considering that muscle co-activation increases compressive forces at the knee joint, identifying relationships between muscle co-activations and knee joint load would complement the investigation of the knee loading in subjects with knee osteoarthritis. The purpose of this study was to identify relationships between muscle co-activation and external knee moments during walking in subjects with medial knee osteoarthritis. 19 controls (11 males, aged 56.6±5, and BMI 25.2±3.3) and 25 subjects with medial knee osteoarthritis (12 males, aged 57.3±5.3, and BMI 28.2±4) were included in this study. Knee adduction and flexion moments, and co-activation (ratios and sums of quadriceps, hamstring, and gastrocnemius) were assessed during walking and compared between groups. The relationship between knee moments and co-activation was investigated in both groups. Subjects with knee osteoarthritis presented a moderate and strong correlation between co-activation (ratios and sums) and knee moments. Muscle co-activation should be used to measure the contribution of quadriceps, hamstring, and gastrocnemius on knee loading. This information would cooperate to develop a more comprehensive approach of knee loading in this population. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. A national questionnaire survey on knee manipulation following total knee arthroplasty.

    PubMed

    Vun, Shen Hwa; Shields, David William; Sen, Aroop; Shareef, Sajan; Sinha, Satyajit; Campbell, Alexander Craig

    2015-12-01

    Adequate range of knee motion is critical for successful total knee arthroplasty. While aggressive physical therapy is an important component, manipulation may be a necessary supplement. There seems to be a lack of consensus with variable practices existing in managing stiff postoperative knees following arthroplasty. Hence we aim to determine the current practice and trend among knee surgeons throughout the United Kingdom. Postal questionnaires were sent out to 100 knee surgeons registered with British Association of Knee Surgeons, ensuring that the whole of United Kingdom was well represented. The questions included whether the surgeon used Manipulation Under Anaesthaesia (MUA) as an option for stiff postoperative knees; timing of MUA; use of Continuous Passive Motion (CPM) post-manipulation. We received 82 responses. 46% of respondents performed MUA routinely, 43% sometimes, and 11 never. Majority (71.23%) performed MUA within 3 months of the index procedure. 68% routinely used CPM post-manipulation while 7% of the respondents applied splints or serial cast post MUA. 41% of the surgeons routinely used Patient Controlled Analgaesia ± Regional blocks. Majority (55%) never performed open/arthroscopic debridement of fibrous tissue for adhesiolysis. Knee manipulation requires an additional anaesthetic and may result in complications such as: supracondylar femur fractures, wound dehiscence, patellar tendon avulsions, haemarthrosis, and heterotopic ossification. Moreover studies have shown that manipulation while being an important therapeutic adjunct does not increase the ultimate flexion achieved. Manipulation should be reserved for the patient with difficult and painful flexion in the early postoperative period.

  11. WEAK LENSING MASS RECONSTRUCTION: FLEXION VERSUS SHEAR

    SciTech Connect

    Pires, S.

    2010-11-10

    Weak gravitational lensing has proven to be a powerful tool to map directly the distribution of dark matter in the universe. The technique, currently used, relies on the accurate measurement of the gravitational shear that corresponds to the first-order distortion of the background galaxy images. More recently, a new technique has been introduced that relies on the accurate measurement of the gravitational flexion that corresponds to the second-order distortion of the background galaxy images. This technique should probe structures on smaller scales than that of shear analysis. The goal of this paper is to compare the ability of shear and flexion to reconstruct the dark matter distribution by taking into account the dispersion in shear and flexion measurements. Our results show that the flexion is less sensitive than shear for constructing the convergence maps on scales that are physically feasible for mapping, meaning that flexion alone should not be used to do convergence map reconstruction, even on small scales.

  12. Kinematic analysis of anterior cruciate ligament reconstruction in total knee arthroplasty.

    PubMed

    Liu, Hua-Wei; Ni, Ming; Zhang, Guo-Qiang; Li, Xiang; Chen, Hui; Zhang, Qiang; Chai, Wei; Zhou, Yong-Gang; Chen, Ji-Ying; Liu, Yu-Liang; Cheng, Cheng-Kung; Wang, Yan

    2016-01-01

    This study aims to retain normal knee kinematics after knee replacement surgeries by reconstructing anterior cruciate ligament during total knee arthroplasty. We use computational simulation tools to establish four dynamic knee models, including normal knee model, posterior cruciate ligament retaining knee model, posterior cruciate ligament substituting knee model, and anterior cruciate ligament reconstructing knee model. Our proposed method utilizes magnetic resonance images to reconstruct solid bones and attachments of ligaments, and assemble femoral and tibial components according representative literatures and operational specifications. Dynamic data of axial tibial rotation and femoral translation from full-extension to 135 were measured for analyzing the motion of knee models. The computational simulation results show that comparing with the posterior cruciate ligament retained knee model and the posterior cruciate ligament substituted knee model, reconstructing anterior cruciate ligament improves the posterior movement of the lateral condyle, medial condyle and tibial internal rotation through a full range of flexion. The maximum posterior translations of the lateral condyle, medial condyle and tibial internal rotation of the anterior cruciate ligament reconstructed knee are 15.3 mm, 4.6 mm and 20.6 at 135 of flexion. Reconstructing anterior cruciate ligament in total knee arthroplasty has been approved to be an more efficient way of maintaining normal knee kinematics comparing to posterior cruciate ligament retained and posterior cruciate ligament substituted total knee arthroplasty.

  13. Kinematic analysis of anterior cruciate ligament reconstruction in total knee arthroplasty

    PubMed Central

    Liu, Hua-Wei; Ni, Ming; Zhang, Guo-Qiang; Li, Xiang; Chen, Hui; Zhang, Qiang; Chai, Wei; Zhou, Yong-Gang; Chen, Ji-Ying; Liu, Yu-Liang; Cheng, Cheng-Kung; Wang, Yan

    2016-01-01

    Background: This study aims to retain normal knee kinematics after knee replacement surgeries by reconstructing anterior cruciate ligament during total knee arthroplasty. Method: We use computational simulation tools to establish four dynamic knee models, including normal knee model, posterior cruciate ligament retaining knee model, posterior cruciate ligament substituting knee model, and anterior cruciate ligament reconstructing knee model. Our proposed method utilizes magnetic resonance images to reconstruct solid bones and attachments of ligaments, and assemble femoral and tibial components according representative literatures and operational specifications. Dynamic data of axial tibial rotation and femoral translation from full-extension to 135 were measured for analyzing the motion of knee models. Findings: The computational simulation results show that comparing with the posterior cruciate ligament retained knee model and the posterior cruciate ligament substituted knee model, reconstructing anterior cruciate ligament improves the posterior movement of the lateral condyle, medial condyle and tibial internal rotation through a full range of flexion. The maximum posterior translations of the lateral condyle, medial condyle and tibial internal rotation of the anterior cruciate ligament reconstructed knee are 15.3 mm, 4.6 mm and 20.6 at 135 of flexion. Interpretation: Reconstructing anterior cruciate ligament in total knee arthroplasty has been approved to be an more efficient way of maintaining normal knee kinematics comparing to posterior cruciate ligament retained and posterior cruciate ligament substituted total knee arthroplasty. PMID:27347334

  14. Knee rotation in healthy individuals related to age and gender.

    PubMed

    Almquist, Per O; Ekdahl, Charlotte; Isberg, Per-Erik; Fridén, Thomas

    2013-01-01

    An external device ("the Rottometer") was especially designed to measure passive knee rotation in vivo. The device had earlier been evaluated with respect to it's validity and reliability. In the present study, we evaluated knee rotation in knee-healthy individuals and studied possible age and gender related differences. Measurements of total internal-external rotation were made at 90°, 60°, and 30° of flexion using 6 and 9 N m torques, as well as the examiner's apprehension of end-feel as displacing forces. The study group constituted of 120 healthy subjects (60 females and 60 males) with no prior or present knee disorders. The sample was divided into four age groups (15-30, 31-45, 46-60, and >60 years). The results showed no differences in knee rotation between the right and left knees or between the different flexion angles. The females showed 10-20% (p < 0.01) larger knee rotation than the males at all the three flexion angles and at all the three applied torques in all age-matched groups. In all age groups in both genders, the internal rotation accounted for 40-44% and the external for 56-60% of the total internal-external knee rotation. Copyright © 2012 Orthopaedic Research Society.

  15. Novel knee joint mechanism of transfemoral prosthesis for stair ascent.

    PubMed

    Inoue, Koh; Wada, Takahiro; Harada, Ryuchi; Tachiwana, Shinichi

    2013-06-01

    The stability of a transfemoral prosthesis when walking on flat ground has been established by recent advances in knee joint mechanisms and their control methods. It is, however, difficult for users of a transfemoral prosthesis to ascend stairs. This difficulty is mainly due to insufficient generation of extension moment around the knee joint of the prosthesis to lift the body to the next step on the staircase and prevent any unexpected flexion of the knee joint in the stance phase. Only a prosthesis with an actuator has facilitated stair ascent using a step-over-step gait (1 foot is placed per step). However, its use has issues associated with the durability, cost, maintenance, and usage environment. Therefore, the purpose of this research is to develop a novel knee joint mechanism for a prosthesis that generates an extension moment around the knee joint in the stance phase during stair ascent, without the use of any actuators. The proposed mechanism is based on the knowledge that the ground reaction force increases during the stance phase when the knee flexion occurs. Stair ascent experiments with the prosthesis showed that the proposed prosthesis can realize stair ascent without any undesirable knee flexion. In addition, the prosthesis is able to generate a positive knee joint moment power in the stance phase even without any power source.

  16. Double-bundle reconstruction cannot restore intact knee kinematics in the ACL/LCL-deficient knee.

    PubMed

    Zantop, Thore; Schumacher, Tobias; Schanz, Steffen; Raschke, Michael J; Petersen, Wolf

    2010-08-01

    The aim of this study was to evaluate the effect of single-bundle (SB) and anatomic double-bundle (DB) anterior cruciate ligament (ACL) reconstruction on the resulting knee kinematics in a simulated clinical setting with ACL rupture and associated extra-articular damage to the lateral structures. It was hypothesized that anatomic DB ACL reconstruction restores the intact knee kinematics in ACL/LCL-deficient knees, whereas SB ACL reconstruction fails to restore the intact knee kinematics. Ten fresh-frozen human cadaver knees were subjected to anterior tibial load of 134 N (simulated KT 1000) and combined rotatory load of 10-Nm valgus and 4-Nm internal tibial torque (simulated pivot shift) using a robotic/UFS testing system. The resulting knee kinematics was determined for intact, ACL/LCL-deficient, SB ACL-reconstructed/LCL-deficient, and DB ACL-reconstructed/LCL-deficient knee. Statistical analysis was performed using a two-way ANOVA test with the level of significance set at P < 0.05. Under a simulated KT 1000 test, anterior tibial translation (ATT) following SB ACL reconstruction was statistically significant at 0 degrees , 30 degrees and 60 degrees of knee flexion when compared to the intact knee. ATT after DB ACL reconstruction showed no statistically significant difference from the intact knee; however, there was a significant difference in SB reconstruction at 0 degrees and 30 degrees of knee flexion. Under a simulated pivot shift test, both SB and DB ACL reconstruction failed to restore the intact knee kinematics. The results of the study did not support our initial hypothesis. Though DB reconstructions were significantly superior to SB reconstruction under simulated KT 1000 test, SB as well as DB reconstruction failed to restore the intact kinematics under simulated pivot shift loads. The clinical relevance of this study is that caution and precise preoperative diagnostics are needed to avoid failure of intra-articular ACL reconstruction if the extra

  17. Reliability of an isokinetic dorsiflexion and plantar flexion apparatus.

    PubMed

    Wennerberg, D

    1991-01-01

    The insufficient amount of research to support high reliability of isokinetic ankle joint adaptations indicates a need for study in this area. Certain brands of isokinetic machinery and specific joint apparatuses have been studied for consistency in adequate numbers of investigations, while there has been little research done on other brands and all other joint adaptations besides the knee. We studied the Biodex B-2000 dorsiflexion and plantar flexion adaptation for reliability between two trials of contractions measuring peak torque. Our results showed generally low reliability coefficients between trials in every condition tested with respect to each ankle motion and two different isokinetic speeds. No connection was seen between ankle motion and isokinetic speed with respect to reliability. Attempts to pinpoint reasons behind inconsistencies concentrate upon such areas as the subject testing position, time between trials, and machine structure. Areas of further study might deal with different brands of isokinetic devices and also the different joint adaptations.

  18. How accurate are lockable orthotic knee braces? An objective gait analysis study.

    PubMed

    Khan, W S; Jones, R K; Nokes, L; Johnson, D S

    2007-12-01

    There has been an increasing use of orthotic knee braces in the management of knee injuries but, to our knowledge, there is no gait analysis study assessing the accuracy of these braces. Eight healthy male subjects were studied to determine the accuracy of immobilisation or splintage provided by a lockable orthotic knee brace using gait analysis. Six types of immobilisation were studied: locked at 0, 10, 20, 30 degrees and unlocked in an orthotic knee brace, and without a brace. The knee flexion angles measured using the kinematic instruments at 0 and 10 degrees were significantly greater than those set at the knee brace. The knee flexion angle measured using the unlocked knee brace was significantly greater than that measured in the absence of a brace. This study highlights inaccuracies in a knee brace at low knee flexion angles. The higher actual angles alter the biomechanics of the knee joint and result in greater forces across the knee joint and especially the extensor mechanism.

  19. A comparative analysis between fixed bearing total knee arthroplasty (PFC Sigma) and rotating platform total knee arthroplasty (PFC-RP) with minimum 3-year follow-up.

    PubMed

    Jawed, Akram; Kumar, Vijay; Malhotra, R; Yadav, C S; Bhan, S

    2012-06-01

    Since the introduction of mobile bearing total knee designs nearly 30 years back, many studies have been done to evaluate its long-term result. Comparison with fixed bearing designs has been done in the past, but the studies were confounded by variables such as disease, surgeon, bone quality, pain tolerance, etc. We attempt to eliminate these variables in this study. A total of 50 patients who had bilateral arthritis of the knee with similar deformity and pre-operative range of motion on both sides agreed to have one knee replaced with mobile bearing total knee design (PFC-RP) and the other with a fixed bearing design (PFC Sigma) were prospectively evaluated. Comparative analysis of both the designs was done at a mean follow-up of 40 months, minimizing patient, surgeon and observer related bias. Clinical and radiographic outcome, survival and complication rates were compared. At a mean follow-up of 40 months (range 36-47 months), no benefit of mobile bearing (PFC-RP) over fixed bearing design (PFC Sigma) could be demonstrated with respect to Knee Society scores, pain scores, range of flexion, subject preference or patello-femoral complication rates. Radiographs showed no difference in prosthetic alignment. No patient required a revision surgery till last follow-up. Our study demonstrated no advantage of the mobile-bearing arthroplasty over fixed bearing arthroplasty with regard to clinical results at short-term follow-up. However, longer follow-up is necessary to confirm whether these results are sustained.

  20. Biomechanical effect of electromechanical knee-ankle-foot-orthosis on knee joint control in patients with poliomyelitis.

    PubMed

    Hwang, Sungjae; Kang, Sungjae; Cho, Kanghee; Kim, Youngho

    2008-06-01

    In this study, an ideal electromechanical KAFO, satisfying stability in the stance and knee flexion in the swing phase during walking, was developed. Biomechanical evaluations were performed on four polio patients by means of three-dimensional gait analyses and energy consumption studies. From the three-dimensional gait analysis on poliomyelitis patients, a considerable amount of knee flexion during the swing phase was observed in controlled-knee gait, which resulted in approximately 33% less energy consumption than in locked-knee gait. The developed electromechanical KAFO in this study was helpful in poliomyelitis patients having partial or complete paralysis of the lower extremity, providing both stability in the stance and free swinging of the knee. This unit was efficient in the transfer of energy.

  1. How effective is multiple needle puncturing for medial soft tissue balancing during total knee arthroplasty? A cadaveric study.

    PubMed

    Koh, In Jun; Kwak, Dai-Soon; Kim, Tae Kyun; Park, In Joo; In, Yong

    2014-12-01

    We investigated the quantitative effect and risk factors for over-release during multiple needle puncturing (MNP) for medial gap balancing in varus total knee arthroplasty (TKA). Of the ten pairs of cadaveric knees, one knee from each pair was randomly assigned to undergo MNP in extension (E group), while the other knee underwent MNP in flexion (F group). The increased extension and 90° flexion gaps after every five needle punctures were measured until over-release occurred. The extension gap (< 4mm) and the 90° flexion gap (< 6mm) gradually increased in both groups. The 90° flexion gaps increased more selectively than did the extension gaps. MNP in the flexed knee, a narrow MCL, and severe osteoarthritis were associated with a smaller number of MNPs required to over-release.

  2. Anterior knee pain after total knee arthroplasty: does it correlate with patellar blood flow?

    PubMed

    Kohl, Sandro; Evangelopoulos, Dimitrios S; Hartel, Maximilian; Kohlhof, Hendrik; Roeder, Christoph; Eggli, Stefan

    2011-09-01

    Total knee arthroplasty (TKA) disturbs patellar blood flow, an unintended accompaniment to TKA that may be a cause of postoperative anterior knee pain. We examine whether disrupted patellar blood flow correlates with anterior knee pain following TKA. In 50 patients (21 men, 29 women) undergoing TKA, we compared patellar blood flow at flexions 0° to 30°, 60°, 90°, and 110° before and after medial parapatellar arthrotomy to pre- and postoperative anterior knee pain scores by means of a laser Doppler flowmeter (LDF) probe. Anterior knee pain was assessed using the pain intensity numeric rating scale (NRS) of 0-10 (0-no, 10-worst pain). Based on the NRS pain values, patients were divided into two main groups: group A (n = 34) with no pain or discomfort (NRS range 0-4) and group B (n = 16) with anterior knee pain (NRS range 5-10). Patients of group B demonstrated a significant decrease in blood flow before arthrotomy at flexions from 0° to 90°, and 110° and from 0° to 60°, 90°, and 110° after arthrotomy. For group A, a significant decrease in blood flow was detected at flexions from 0° to 90°, and 110° before and after arthrotomy. For both groups, medial arthrotomy did not have a statistically significant influence on patellar blood flow (margin of significance P < 0.05). Prior to TKA, 16 of the 50 patients of group B (32%) complained of anterior knee pain (mean NRS 7.1 ± 1.7). At 2-year follow-up, pain significantly decreased (NRS 3.1 ± 2.1) and only 4 of the 16 patients (25%) complained of moderate anterior pain (average NRS 5.7 ± 0.5), while 8 of 16 (50%) patients reported discomfort (mean NRS 3.5 ± 1.8) around the patella. Patients in group A also demonstrated a significant decrease in pain intensity (from NRS 1.5 ± 1.4 preoperatively to NRS 0.4 ± 1.5 at 2-year follow-up). Statistical analysis demonstrated no statistically significant correlation between pre-arthrotomy/post-arthrotomy patellar blood flow and the presence of preoperative and

  3. Bilateral total knee arthroplasty in a patient with hemophilia A, high inhibitor titre and aneurysma spurium of the popliteal artery. A case report.

    PubMed

    Frauchiger, Lars Henrik; Harstall, Roger; Kajahn, Jennifer; Anderson, Suzanne; Eggli, Stefan

    2010-08-24

    The authors report on bilateral simultaneous knee arthroplasty in a 40-year-old male patient with haemophilia A, high inhibitor titre and an aneurysma spurium of the right popliteal artery. Both knees showed a fixed flexion deformity of 20 degrees. To build up haemostasis, treatment with activated prothrombin complex concentrate (APCC) and recombinant activated factor seven (rFVIIa) was initiated preoperatively. A tourniquet was used on both sides during the operation and factor VIII (FVIII) was administered to further correct coagulopathy. On the eleventh postoperative day the patient complained of increasing pain and pressure in the right knee. An ultrasound suggested aneurysm, which was confirmed by substraction angiography. Under the protection of rFVIIa the aneurysm could be coiled and further rehabilitation was uneventful. At one year post-op the patient presented a range of motion of 90/5/0 degrees for both knees and had returned to full time office work. This case indicates that haemophiliacs with high antibody titre and destruction of both knees can be operated on in one session in order to diminish the operative risk of two consecutive surgical procedures, thus allowing an effective rehabilitation programme. Because of the significant frequency of popliteal aneurysms, preoperative angiography is recommended.

  4. Weight-bearing condyle motion of the knee before and after cruciate-retaining TKA: In-vivo surgical transepicondylar axis and geometric center axis analyses.

    PubMed

    Dimitriou, Dimitris; Tsai, Tsung-Yuan; Park, Kwan Kyu; Hosseini, Ali; Kwon, Young-Min; Rubash, Harry E; Li, Guoan

    2016-06-14

    An equal knee joint height during flexion and extension is of critical importance in optimizing soft-tissue balancing following total knee arthroplasty (TKA). However, there is a paucity of data regarding the in-vivo knee joint height behavior. This study evaluated in-vivo heights and anterior-posterior (AP) translations of the medial and lateral femoral condyles before and after a cruciate-retaining (CR)-TKA using two flexion axes: surgical transepicondylar axis (sTEA) and geometric center axis (GCA). Eleven osteoarthritis (OA) knee patients were studied during a weight-bearing single leg lunge, using a validated dual fluoroscopic imaging system (DFIS) based tracking technique. Eight healthy subjects were recruited as controls. The results demonstrated that following TKA, the medial and lateral femoral condyle heights were not equal at mid-flexion (15-45°, medial condyle lower then lateral by 2.4mm at least, p<0.01), although the knees were well-balanced at 0° and 90°. While the femoral condyle heights increased from the pre-operative values (>2mm increase on average, p<0.05), they were similar to the intact knees except that the medial sTEA was lower than the intact medial condyle between 0° and 90°. At deep flexion (>90°), both condyles were significantly higher (>2mm, p<0.01) than the healthy knees. Anterior femoral translation of the TKA knee was more pronounce at mid-flexion, whereas limited posterior translation was found at deep flexion. These data suggest that a well-balanced knee intra-operatively might not necessarily result in mid-flexion and deep flexion balance during functional weight-bearing motion, implying mid-flexion instability and deep flexion tightness of the knee.

  5. Knee pain, knee injury, knee osteoarthritis & work.

    PubMed

    Dulay, Gurdeep S; Cooper, C; Dennison, E M

    2015-06-01

    Symptomatic knee osteoarthritis (OA) can be viewed as the end result of a molecular cascade which ensues after certain triggers occur and ultimately results in irreversible damage to the articular cartilage. The clinical phenotype that knee OA can produce is variable and often difficult to accurately predict. This is further complicated by the often poor relationship between radiographic OA and knee pain. As a consequence, it can be difficult to compare studies that use different definitions of OA. However, the literature suggests that while there are multiple causes of knee OA, two have attracted particular attention over recent years; occupation related knee OA and OA subsequent to previous knee injury. The evidence of a relationship, and the strength of this association, is discussed in this chapter.

  6. Maximum Velocities in Flexion and Extension Actions for Sport

    PubMed Central

    Jessop, David M.

    2016-01-01

    Abstract Speed of movement is fundamental to the outcome of many human actions. A variety of techniques can be implemented in order to maximise movement speed depending on the goal of the movement, constraints, and the time available. Knowing maximum movement velocities is therefore useful for developing movement strategies but also as input into muscle models. The aim of this study was to determine maximum flexion and extension velocities about the major joints in upper and lower limbs. Seven university to international level male competitors performed flexion/extension at each of the major joints in the upper and lower limbs under three conditions: isolated; isolated with a countermovement; involvement of proximal segments. 500 Hz planar high speed video was used to calculate velocities. The highest angular velocities in the upper and lower limb were 50.0 rad·s-1 and 28.4 rad·s-1, at the wrist and knee, respectively. As was true for most joints, these were achieved with the involvement of proximal segments, however, ANOVA analysis showed few significant differences (p<0.05) between conditions. Different segment masses, structures and locations produced differing results, in the upper and lower limbs, highlighting the requirement of segment specific strategies for maximal movements. PMID:28149339

  7. The influence of a powered knee-ankle-foot orthosis on walking in poliomyelitis subjects: A pilot study.

    PubMed

    Arazpour, Mokhtar; Moradi, Alireza; Samadian, Mohammad; Bahramizadeh, Mahmood; Joghtaei, Mahmoud; Ahmadi Bani, Monireh; Hutchins, Stephen W; Mardani, Mohammad A

    2016-06-01

    Traditionally, the anatomical knee joint is locked in extension when walking with a conventional knee-ankle-foot orthosis. A powered knee-ankle-foot orthosis was developed to provide restriction of knee flexion during stance phase and active flexion and extension of the knee during swing phase of gait. The purpose of this study was to determine differences of the powered knee-ankle-foot orthosis compared to a locked knee-ankle-foot orthosis in kinematic data and temporospatial parameters during ambulation. Quasi-experimental design. Subjects with poliomyelitis (n = 7) volunteered for this study and undertook gait analysis with both the powered and the conventional knee-ankle-foot orthoses. Three trials per orthosis were collected while each subject walked along a 6-m walkway using a calibrated six-camera three-dimensional video-based motion analysis system. Walking with the powered knee-ankle-foot orthosis resulted in a significant reduction in both walking speed and step length (both 18%), but a significant increase in stance phase percentage compared to walking with the conventional knee-ankle-foot orthosis. Cadence was not significantly different between the two test conditions (p = 0.751). There was significantly higher knee flexion during swing phase and increased hip hiking when using the powered orthosis. The new powered orthosis permitted improved knee joint kinematic for knee-ankle-foot orthosis users while providing knee support in stance and active knee motion in swing in the gait cycle. Therefore, the new powered orthosis provided more natural knee flexion during swing for orthosis users compared to the locked knee-ankle-foot orthosis. This orthosis has the potential to improve knee joint kinematics and gait pattern in poliomyelitis subjects during walking activities. © The International Society for Prosthetics and Orthotics 2015.

  8. Evaluation of total knee mechanics using a crouching simulator with a synthetic knee substitute.

    PubMed

    Lowry, Michael; Rosenbaum, Heather; Walker, Peter S

    2016-05-01

    Mechanical evaluation of total knees is frequently required for aspects such as wear, strength, kinematics, contact areas, and force transmission. In order to carry out such tests, we developed a crouching simulator, based on the Oxford-type machine, with novel features including a synthetic knee including ligaments. The instrumentation and data processing methods enabled the determination of contact area locations and interface forces and moments, for a full flexion-extension cycle. To demonstrate the use of the simulator, we carried out a comparison of two different total knee designs, cruciate retaining and substituting. The first part of the study describes the simulator design and the methodology for testing the knees without requiring cadaveric knee specimens. The degrees of freedom of the anatomic hip and ankle joints were reproduced. Flexion-extension was obtained by changing quadriceps length, while variable hamstring forces were applied using springs. The knee joint was represented by three-dimensional printed blocks on to which the total knee components were fixed. Pretensioned elastomeric bands of realistic stiffnesses passed through holes in the block at anatomical locations to represent ligaments. Motion capture of the knees during flexion, together with laser scanning and computer modeling, was used to reconstruct contact areas on the bearing surfaces. A method was also developed for measuring tibial component interface forces and moments as a comparative assessment of fixation. The method involved interposing Tekscan pads at locations on the interface. Overall, the crouching machine and the methodology could be used for many different mechanical measurements of total knee designs, adapted especially for comparative or parametric studies.

  9. The influence of pain on knee motion in patients with osteoarthritis undergoing total knee arthroplasty.

    PubMed

    Bennett, Damien; Hanratty, Brian; Thompson, Neville; Beverland, David E

    2009-04-01

    Pain is the predominant symptom of degenerative knee arthritis and the main reason patients undergo total knee arthroplasty (TKA). Variation in patient response to pain has proved difficult to quantify. The effect of removing pain by testing TKA patients' range of motion (ROM) before and after the administration of anesthesia has not previously been analyzed. This study objectively quantifies the effect of eliminating pain on knee joint ROM for a typical group of TKA patients with osteoarthritis. We prospectively recruited 141 patients with osteoarthritis admitted for TKA to assess the inhibitory effect of pain on ROM. Passive maximum flexion, extension, and ROM were measured preoperatively before and after administration of anesthesia (spinal anesthetic followed by femoral and sciatic regional nerve blocks). Following pain abolition, passive maximum flexion increased by an average of 13.4 degrees (SD=11.9 degrees), passive maximum extension improved by an average of 3.0 degrees (SD=4.2 degrees), and passive ROM increased by an average of 16.4 degrees (SD=13.1 degrees). The change in each parameter was statistically significant (P<.0001). Improvements in flexion (P=.01) and ROM (P=.005) were significantly greater in women. Measurements taken before anesthesia reflect knee ROM that the patient will tolerate before pain becomes the limiting factor, while measurements taken after anesthesia is achieved suggest the knee ROM possible once pain is eliminated. Abolition of pain led to significant increases in knee flexion, extension, and ROM, suggesting that pain has a significant inhibitory effect on knee motion.

  10. [Congenital knee dislocation: case report].

    PubMed

    Arvinius, C; Luque, R; Díaz-Ceacero, C; Marco, F

    2016-01-01

    Congenital knee dislocation is an infrequent condition with unknown etiology. In some cases it occurs as an isolated condition, while in others it coexists with associated conditions or syndromes. The treatment of congenital knee dislocation is driven by the severity and flexibility of the deformity. The literature includes from serial casting or the Pavlik harness to quadriceps tendon plasty or femoral osteotomies. We report herein the case of a congenital dislocation treated with serial casting with a good outcome.

  11. Predictors of outcome after manipulation under anaesthesia in patients with a stiff total knee arthroplasty.

    PubMed

    Vanlommel, L; Luyckx, T; Vercruysse, G; Bellemans, J; Vandenneucker, H

    2016-12-29

    Flexion in a stiff total knee arthroplasty (TKA) can be improved by manipulation under anaesthesia (MUA). Although this intervention usually results in an improvement in range of motion, the expected result is not always achieved. The purpose of this study is to determine which factors affect range of motion after manipulation in patients with a stiff total knee. After exclusion (n = 22), the data of 158 patients (138 knees) with a stiff knee after TKA who received a manipulation under anaesthesia between 2004 and 2014 were retrospectively analysed. Pre-, peri- and post-operative variables were identified and examined for their influence on flexion after the manipulation using Kruskal-Wallis and Mann-Whitney U tests and Spearman correlations. After MUA, a mean improvement in flexion of 30.3° was observed at the final follow-up. Preoperative TKA flexion, design of TKA and interval between TKA procedure and MUA were positive associated with an increase in flexion after MUA. MUA performed 12 weeks or more after TKA procedure deteriorated the outcome. Three factors, pre-TKA flexion type of prosthesis and interval between TKA procedure and manipulation under anaesthesia, were found to have impact on flexion after TKA and MUA were identified. Results are expected to be inferior in patients with low flexion before TKA procedure or with a long interval (>12 weeks) between the TKA procedure and the manipulation under anaesthesia. IV.

  12. Head flexion angle while using a smartphone.

    PubMed

    Lee, Sojeong; Kang, Hwayeong; Shin, Gwanseob

    2015-01-01

    Repetitive or prolonged head flexion posture while using a smartphone is known as one of risk factors for pain symptoms in the neck. To quantitatively assess the amount and range of head flexion of smartphone users, head forward flexion angle was measured from 18 participants when they were conducing three common smartphone tasks (text messaging, web browsing, video watching) while sitting and standing in a laboratory setting. It was found that participants maintained head flexion of 33-45° (50th percentile angle) from vertical when using the smartphone. The head flexion angle was significantly larger (p < 0.05) for text messaging than for the other tasks, and significantly larger while sitting than while standing. Study results suggest that text messaging, which is one of the most frequently used app categories of smartphone, could be a main contributing factor to the occurrence of neck pain of heavy smartphone users. Practitioner Summary: In this laboratory study, the severity of head flexion of smartphone users was quantitatively evaluated when conducting text messaging, web browsing and video watching while sitting and standing. Study results indicate that text messaging while sitting caused the largest head flexion than that of other task conditions.

  13. Torso flexion modulates stiffness and reflex response.

    PubMed

    Granata, K P; Rogers, E

    2007-08-01

    Neuromuscular factors that contribute to spinal stability include trunk stiffness from passive and active tissues as well as active feedback from reflex response in the paraspinal muscles. Trunk flexion postures are a recognized risk factor for occupational low-back pain and may influence these stabilizing control factors. Sixteen healthy adult subjects participated in an experiment to record trunk stiffness and paraspinal muscle reflex gain during voluntary isometric trunk extension exertions. The protocol was designed to achieve trunk flexion without concomitant influences of external gravitational moment, i.e., decouple the effects of trunk flexion posture from trunk moment. Systems identification analyses identified reflex gain by quantifying the relation between applied force disturbances and time-dependent EMG response in the lumbar paraspinal muscles. Trunk stiffness was characterized from a second order model describing the dynamic relation between the force disturbances versus the kinematic response of the torso. Trunk stiffness increased significantly with flexion angle and exertion level. This was attributed to passive tissue contributions to stiffness. Reflex gain declined significantly with trunk flexion angle but increased with exertion level. These trends were attributed to correlated changes in baseline EMG recruitment in the lumbar paraspinal muscles. Female subjects demonstrated greater reflex gain than males and the decline in reflex gain with flexion angle was greater in females than in males. Results reveal that torso flexion influences neuromuscular factors that control spinal stability and suggest that posture may contribute to the risk of instability injury.

  14. Examining Ankle-Joint Laxity Using 2 Knee Positions and With Simulated Muscle Guarding

    PubMed Central

    Hanlon, Shawn; Caccese, Jaclyn; Knight, Christopher A.; Swanik, Charles “Buz”; Kaminski, Thomas W.

    2016-01-01

    Context:  Several factors affect the reliability of the anterior drawer and talar tilt tests, including the individual clinician's experience and skill, ankle and knee positioning, and muscle guarding. Objectives:  To compare gastrocnemius activity during the measurement of ankle-complex motion at different knee positions, and secondarily, to compare ankle-complex motion during a simulated trial of muscle guarding. Design:  Cross-sectional study. Setting:  Research laboratory. Patients or Other Participants:  Thirty-three participants aged 20.2 ± 1.7 years were tested. Intervention(s):  The ankle was loaded under 2 test conditions (relaxed, simulated muscle guarding) at 2 knee positions (0°, 90° of flexion) while gastrocnemius electromyography (EMG) activity was recorded. Main Outcome Measure(s):  Anterior displacement (mm), inversion-eversion motion (°), and peak EMG amplitude values of the gastrocnemius (μV). Results:  Anterior displacement did not differ between the positions of 0° and 90° of knee flexion (P = .193). Inversion-eversion motion was greater at 0° of knee flexion compared with 90° (P < .001). Additionally, peak EMG amplitude of the gastrocnemius was not different between 0° and 90° of knee flexion during anterior displacement (P = .101). As expected, the simulated muscle-guarding trial reduced anterior displacement compared with the relaxed condition (0° of knee flexion, P = .008; 90° of knee flexion, P = .016) and reduced inversion-eversion motion (0° of knee flexion, P = .03; 90° of knee flexion, P < .001). Conclusions:  In a relaxed state, the gastrocnemius muscle did not appear to affect anterior ankle laxity at the 2 most common knee positions for anterior drawer testing; however, talar tilt testing may be best performed with the knee in 0° of knee flexion. Finally, our outcomes from the simulated muscle-guarding condition suggest that clinicians should use caution and be aware of reduced perceived laxity when

  15. Intraoperative evaluation of total knee replacement: kinematic assessment with a navigation system.

    PubMed

    Casino, Daniela; Zaffagnini, Stefano; Martelli, Sandra; Lopomo, Nicola; Bignozzi, Simone; Iacono, Francesco; Russo, Alessandro; Marcacci, Maurilio

    2009-04-01

    Interest in the kinematics of reconstructed knees has increased since it was shown that the alteration of knee motion could lead to abnormal wear and damage to soft tissues. We performed intraoperative kinematic measurements using a navigation system to study knee kinematics before and after posterior substituting rotating platform total knee arthroplasty (TKA). We verified intraoperatively (1) if varus/valgus (VV) laxity and anterior/posterior (AP) laxity were restored after TKA; (2) if TKA induced abnormal femoral rollback; and (3) how tibial axial rotation was influenced by TKA throughout the range of flexion. We found that TKA improved alignment in preoperative osteoarthritic varus knees which became neutral after surgery and maintained a neutral alignment in neutral knees. The VV stability at 0 degrees was restored while AP laxity at 90 degrees significantly increased after TKA. Following TKA, the femur had an abnormal anterior translation up to 60 degrees of flexion, followed by a small rollback of 12 +/- 5 mm. TKA influenced the tibia rotation pattern during flexion, but not the total amount of internal/external rotation throughout whole range of flexion, which was preserved after TKA (6 degrees +/- 5 degrees ). This study showed that the protocol proposed might be useful to adjust knee stability at time zero and that knee kinematic outcome during total knee replacement can be monitored by a navigation system.

  16. Correction of tibial deformity in Paget's disease using the Taylor spatial frame.

    PubMed

    Tsaridis, E; Sarikloglou, S; Papasoulis, E; Lykoudis, S; Koutroumpas, I; Avtzakis, V

    2008-02-01

    A 64-year-old man presented with a severe deformity of the tibia caused by Paget's disease and osteoarthritis of the ipsilateral knee. Total knee replacement required preliminary correction of the tibial deformity. This was successfully achieved by tibial osteotomy followed by distraction osteogenesis using the Taylor spatial frame. The subsequent knee replacement was successful, with no recurrence of deformity.

  17. Image Segmentation and Analysis of Flexion-Extension Radiographs of Cervical Spines

    PubMed Central

    Enikov, Eniko T.

    2014-01-01

    We present a new analysis tool for cervical flexion-extension radiographs based on machine vision and computerized image processing. The method is based on semiautomatic image segmentation leading to detection of common landmarks such as the spinolaminar (SL) line or contour lines of the implanted anterior cervical plates. The technique allows for visualization of the local curvature of these landmarks during flexion-extension experiments. In addition to changes in the curvature of the SL line, it has been found that the cervical plates also deform during flexion-extension examination. While extension radiographs reveal larger curvature changes in the SL line, flexion radiographs on the other hand tend to generate larger curvature changes in the implanted cervical plates. Furthermore, while some lordosis is always present in the cervical plates by design, it actually decreases during extension and increases during flexion. Possible causes of this unexpected finding are also discussed. The described analysis may lead to a more precise interpretation of flexion-extension radiographs, allowing diagnosis of spinal instability and/or pseudoarthrosis in already seemingly fused spines. PMID:27006937

  18. Metatarsophalangeal Hyperextension Movement Pattern Related to Diabetic Forefoot Deformity

    PubMed Central

    Hastings, Mary K.; Mueller, Michael J.

    2016-01-01

    Background Metatarsophalangeal joint (MTPJ) hyperextension deformity is common in people with diabetic neuropathy and a known risk factor for ulceration and amputation. An MTPJ hyperextension movement pattern may contribute to the development of this acquired deformity. Objective The purpose of this study was to determine, in people with diabetes mellitus and peripheral neuropathy (DM+PN), the ankle and MTPJ ranges of motion that characterize an MTPJ hyperextension movement pattern and its relationship to MTPJ deformity severity. It was hypothesized that severity of MTPJ deformity would be related to limitations in maximum ankle dorsiflexion and increased MTPJ extension during active ankle dorsiflexion movement tasks. Design A cross-sectional study design was used that included 34 people with DM+PN (mean age=59 years, SD=9). Methods Computed tomography and 3-dimensional motion capture analysis were used to measure resting MTPJ angle and intersegmental foot motion during the tasks of ankle dorsiflexion and plantar flexion with the knee extended and flexed to 90 degrees, walking, and sit-to/from-stand. Results The MTPJ extension movement pattern during all tasks was directly correlated with severity of MTPJ deformity: maximum ankle dorsiflexion with knee extended (r=.35; 95% confidence interval [CI]=.02, .62), with knee flexed (r=.35; 95% CI=0.01, 0.61), during the swing phase of gait (r=.47; 95% CI=0.16, 0.70), during standing up (r=.48; 95% CI=0.17, 0.71), and during sitting down (r=.38; 95% CI=0.05, 0.64). All correlations were statistically significant. Limitations This study was cross-sectional, and causal relationships cannot be made. Conclusions A hyperextension MTPJ movement pattern associated with limited ankle dorsiflexion has been characterized in people with diabetic neuropathy. Increased MTPJ extension during movement and functional tasks was correlated with severity of resting MTPJ alignment. Repetition of this movement pattern could be an important

  19. The effect of different types of insoles or shoe modifications on medial loading of the knee in persons with medial knee osteoarthritis: a randomised trial

    PubMed Central

    Chapman, Graham J.; Parkes, Matthew J.; Forsythe, Laura.; Felson, David T.

    2015-01-01

    ABSTRACT Many conservative treatments exist for medial knee osteoarthritis (OA) which aims to reduce the external knee adduction moment (EKAM). The objective of this study was to determine the difference between different shoes and lateral wedge insoles on EKAM, knee adduction angular impulse (KAAI), external knee flexion moment, pain, and comfort when walking in individuals with medial knee OA. Seventy individuals with medial knee OA underwent three‐dimensional walking gait analysis in five conditions (barefoot, control shoe, typical wedge, supported wedge, and mobility shoe) with pain and comfort recorded concurrently. The change in EKAM, KAAI, external knee flexion moment, pain, and comfort were assessed using multiple linear regressions and pairwise comparisons. Compared with the control shoe, lateral wedge insoles and barefoot walking significantly reduced early stance EKAM and KAAI. The mobility shoe showed no effect. A significant reduction in latter stance EKAM was seen in the lateral wedge insoles compared to the other conditions, with only the barefoot condition reducing the external knee flexion moment. However, the mobility shoe showed significant immediate knee pain reduction and improved comfort scores. Different lateral wedge insoles show comparable reductions in medial knee loading and in our study, the mobility shoe did not affect medial loading. © 2015 The Authors. Journal of Orthopaedic Research Published by Wiley Periodicals, Inc. J Orthop Res 33:1646–1654, 2015. PMID:25991385

  20. The effect of different types of insoles or shoe modifications on medial loading of the knee in persons with medial knee osteoarthritis: a randomised trial.

    PubMed

    Jones, Richard K; Chapman, Graham J; Parkes, Matthew J; Forsythe, Laura; Felson, David T

    2015-11-01

    Many conservative treatments exist for medial knee osteoarthritis (OA) which aims to reduce the external knee adduction moment (EKAM). The objective of this study was to determine the difference between different shoes and lateral wedge insoles on EKAM, knee adduction angular impulse (KAAI), external knee flexion moment, pain, and comfort when walking in individuals with medial knee OA. Seventy individuals with medial knee OA underwent three-dimensional walking gait analysis in five conditions (barefoot, control shoe, typical wedge, supported wedge, and mobility shoe) with pain and comfort recorded concurrently. The change in EKAM, KAAI, external knee flexion moment, pain, and comfort were assessed using multiple linear regressions and pairwise comparisons. Compared with the control shoe, lateral wedge insoles and barefoot walking significantly reduced early stance EKAM and KAAI. The mobility shoe showed no effect. A significant reduction in latter stance EKAM was seen in the lateral wedge insoles compared to the other conditions, with only the barefoot condition reducing the external knee flexion moment. However, the mobility shoe showed significant immediate knee pain reduction and improved comfort scores. Different lateral wedge insoles show comparable reductions in medial knee loading and in our study, the mobility shoe did not affect medial loading.

  1. Knee kinematics in medial osteoarthritis during in vivo weight-bearing activities.

    PubMed

    Hamai, Satoshi; Moro-oka, Taka-Aki; Miura, Hiromasa; Shimoto, Takeshi; Higaki, Hidehiko; Fregly, Benjamin J; Iwamoto, Yukihide; Banks, Scott A

    2009-12-01

    Dynamic knee kinematics were analyzed for medial osteoarthritic (OA) knees in three activities, including two types of maximum knee flexion. Continuous x-ray images of kneeling, squatting, and stair climbing motions were taken using a large flat panel detector. CT-derived bone models were used for the model registration-based 3D kinematic measurements. Three-dimensional joint kinematics and contact locations were determined using two methods: bone-fixed coordinate systems and by interrogation of CT-based bone model surfaces. The femur exhibited gradual external rotation with knee flexion for kneeling and squatting activities, and gradual internal rotation with knee extension for stair climbing. From 100 degrees to 120 degrees flexion, contact locations showed a medial pivot pattern similar to normal knees. However, knees with medial OA displayed a femoral internal rotation bias and less posterior translation when compared with normal knees. A classic screw-home movement was not observed in OA knees near extension. Decreased variability with both activities and methods of calculation were demonstrated for all three activities. In conclusion, the weight-bearing kinematics of patients with medial OA differs from normal knees. Pathological changes of the articulating surfaces and the ligaments correspond to observed abnormalities in knee kinematics.

  2. Data Collection and Analysis Using Wearable Sensors for Monitoring Knee Range of Motion after Total Knee Arthroplasty.

    PubMed

    Chiang, Chih-Yen; Chen, Kun-Hui; Liu, Kai-Chun; Hsu, Steen Jun-Ping; Chan, Chia-Tai

    2017-02-22

    Total knee arthroplasty (TKA) is the most common treatment for degenerative osteoarthritis of that articulation. However, either in rehabilitation clinics or in hospital wards, the knee range of motion (ROM) can currently only be assessed using a goniometer. In order to provide continuous and objective measurements of knee ROM, we propose the use of wearable inertial sensors to record the knee ROM during the recovery progress. Digitalized and objective data can assist the surgeons to control the recovery status and flexibly adjust rehabilitation programs during the early acute inpatient stage. The more knee flexion ROM regained during the early inpatient period, the better the long-term knee recovery will be and the sooner early discharge can be achieved. The results of this work show that the proposed wearable sensor approach can provide an alternative for continuous monitoring and objective assessment of knee ROM recovery progress for TKA patients compared to the traditional goniometer measurements.

  3. Data Collection and Analysis Using Wearable Sensors for Monitoring Knee Range of Motion after Total Knee Arthroplasty

    PubMed Central

    Chiang, Chih-Yen; Chen, Kun-Hui; Liu, Kai-Chun; Hsu, Steen Jun-Ping; Chan, Chia-Tai

    2017-01-01

    Total knee arthroplasty (TKA) is the most common treatment for degenerative osteoarthritis of that articulation. However, either in rehabilitation clinics or in hospital wards, the knee range of motion (ROM) can currently only be assessed using a goniometer. In order to provide continuous and objective measurements of knee ROM, we propose the use of wearable inertial sensors to record the knee ROM during the recovery progress. Digitalized and objective data can assist the surgeons to control the recovery status and flexibly adjust rehabilitation programs during the early acute inpatient stage. The more knee flexion ROM regained during the early inpatient period, the better the long-term knee recovery will be and the sooner early discharge can be achieved. The results of this work show that the proposed wearable sensor approach can provide an alternative for continuous monitoring and objective assessment of knee ROM recovery progress for TKA patients compared to the traditional goniometer measurements. PMID:28241434

  4. Posterior Cruciate Ligament Removal Contributes to Abnormal Knee Motion during Posterior Stabilized Total Knee Arthroplasty

    PubMed Central

    Cromie, Melinda J.; Siston, Robert A.; Giori, Nicholas J.; Delp, Scott L.

    2017-01-01

    Abnormal anterior translation of the femur on the tibia has been observed in mid flexion (20–60°) following posterior stabilized total knee arthroplasty. The underlying biomechanical causes of this abnormal motion remain unknown. The purpose of this study was to isolate the effects of posterior cruciate ligament removal on knee motion after total knee arthroplasty. We posed two questions: Does removing the posterior cruciate ligament introduce abnormal anterior femoral translation? Does implanting a posterior stabilized prosthesis change the kinematics from the cruciate deficient case? Using a navigation system, we measured passive knee kinematics of ten male osteoarthritic patients during surgery after initial exposure, after removing the anterior cruciate ligament, after removing the posterior cruciate ligament, and after implanting the prosthesis. Passively flexing and extending the knee, we calculated anterior femoral translation and the flexion angle at which femoral rollback began. Removing the posterior cruciate ligament doubled anterior translation (from 5.1±4.3 mm to 10.4±5.1 mm) and increased the flexion angle at which femoral rollback began (from 31.2±9.6° to 49.3±7.3°). Implanting the prosthesis increased the amount of anterior translation (to 16.1±4.4 mm), and did not change the flexion angle at which femoral rollback began. Abnormal anterior translation was observed in low and mid flexion (0–60°) after removing the posterior cruciate ligament, and normal motion was not restored by the posterior stabilized prosthesis. PMID:18464260

  5. Differences in knee joint kinematics and forces after posterior cruciate retaining and stabilized total knee arthroplasty.

    PubMed

    Wünschel, Markus; Leasure, Jeremi M; Dalheimer, Philipp; Kraft, Nicole; Wülker, Nikolaus; Müller, Otto

    2013-12-01

    Posterior cruciate ligament (PCL) retaining (CR) and -sacrificing (PS) total knee arthroplasties (TKA) are widely-used to treat osteoarthritis of the knee joint. The PS design substitutes the function of the PCL with a cam-spine mechanism which may produce adverse changes to joint kinematics and kinetics. CR- and PS-TKA were performed on 11 human knee specimens. Joint kinematics were measured with a dynamic knee simulator and motion tracking equipment. In-situ loads of the PCL and cam-spine were measured with a robotic force sensor system. Partial weight bearing flexions were simulated and external forces were applied. The PS-TKA rotated significantly less throughout the whole flexion range compared to the CR-TKA. Femoral roll back was greater in the PS-TKA; however, this was not correlated with lower quadriceps forces. Application of external loads produced significantly different in-situ force profiles between the TKA systems. Our data demonstrate that the PS-design significantly alters kinematics of the knee joint. Our data also suggest the cam-spine mechanism may have little influence on high flexion kinematics (such as femoral rollback) with most of the load burden shared by supporting implant and soft-tissue structures. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. A Highly Backdrivable, Lightweight Knee Actuator for Investigating Gait in Stroke

    PubMed Central

    Sulzer, James S.; Roiz, Ronald A.; Peshkin, Michael A.; Patton, James L.

    2012-01-01

    Many of those who survive a stroke develop a gait disability known as stiff-knee gait (SKG). Characterized by reduced knee flexion angle during swing, people with SKG walk with poor energy efficiency and asymmetry due to the compensatory mechanisms required to clear the foot. Previous modeling studies have shown that knee flexion activity directly before the foot leaves the ground, and this should result in improved knee flexion angle during swing. The goal of this research is to physically test this hypothesis using robotic intervention. We developed a device that is capable of assisting knee flexion torque before swing but feels imperceptible (transparent) for the rest of the gait cycle. This device uses sheathed Bowden cable to control the deflection of a compliant torsional spring in a configuration known as a Series Elastic Remote Knee Actuator (SERKA). In this investigation, we describe the design and evaluation of SERKA, which includes a pilot experiment on stroke subjects. SERKA could supply a substantial torque (12 N· m) in less than 20 ms, with a maximum torque of 41 N·m. The device resisted knee flexion imperceptibly when desired, at less than 1 N·m rms torque during normal gait. With the remote location of the actuator, the user experiences a mass of only 1.2 kg on the knee. We found that the device was capable of increasing both peak knee flexion angle and velocity during gait in stroke subjects. Thus, the SERKA is a valid experimental device that selectively alters knee kinetics and kinematics in gait after stroke. PMID:22563305

  7. The Transseptal Arthroscopic Knee Portal Is in Close Proximity to the Popliteal Artery: A Cadaveric Study.

    PubMed

    Cancienne, Jourdan M; Werner, Brian C; Burrus, M Tyrrell; Kandil, Abdurrahman; Conte, Evan J; Gwathmey, Frank W; Miller, Mark D

    2017-03-10

    The purpose of this study was to use fluoroscopy to measure the distance between the transseptal portal and the popliteal artery under arthroscopic conditions with an intact posterior knee capsule, and to determine the difference between 90 degrees of knee flexion and full extension. The popliteal artery of eight fresh-frozen cadaveric knees was dissected and cannulated proximal to the knee joint. The posterolateral, posteromedial, and transseptal portals were then established at 90 degrees of flexion. A 4-mm switching stick was placed through the transseptal portal, and barium contrast was injected into the popliteal artery. A lateral fluoroscopic image was taken with the knee in 90 degrees of flexion and full extension, and the distance between the popliteal artery and the switching stick was measured and compared using a paired t-test. In knee flexion, the average distance between the transseptal portal and the anterior aspect of the popliteal artery for the eight cadaveric specimens was 12.0 mm ± 3.3 mm; in extension, this decreased to 9.0 mm ± 2.7 mm. The distance between the transseptal portal and popliteal artery was significantly higher at 90 degrees of knee flexion as compared with extension (p = 0.0005). The transseptal posterior knee arthroscopic portal must be carefully created due to the close proximity to the popliteal artery, and may be closer to the artery than previously reported in specimens with an intact posterior knee capsule. Creating the portal with the knee in flexion significantly displaces the popliteal artery away from the portal reducing the risk of arterial injury.

  8. Sagittal Plane Knee Biomechanics and Vertical Ground Reaction Forces Are Modified Following ACL Injury Prevention Programs

    PubMed Central

    Padua, Darin A.; DiStefano, Lindsay J.

    2009-01-01

    Context: Injuries to the anterior cruciate ligament (ACL) occur because of excessive loading on the knee. ACL injury prevention programs can influence sagittal plane ACL loading factors and vertical ground reaction force (VGRF). Objective: To determine the influence of ACL injury prevention programs on sagittal plane knee biomechanics (anterior tibial shear force, knee flexion angle/moments) and VGRF. Data Sources: The PubMed database was searched for studies published between January 1988 and June 2008. Reference lists of selected articles were also reviewed. Study Selection: Studies were included that evaluated healthy participants for knee flexion angle, sagittal plane knee kinetics, or VGRF after performing a multisession training program. Two individuals reviewed all articles and determined which articles met the selection criteria. Approximately 4% of the articles fulfilled the selection criteria. Data Extraction: Data were extracted regarding each program’s duration, frequency, exercise type, population, supervision, and testing procedures. Means and variability measures were recorded to calculate effect sizes. One reviewer extracted all data and assessed study quality using PEDro (Physiotherapy Evidence Database). A second reviewer (blinded) verified all information. Results: There is moderate evidence to indicate that knee flexion angle, external knee flexion moment, and VGRF can be successfully modified by an ACL injury prevention program. Programs utilizing multiple exercises (ie, integrated training) appear to produce the most improvement, in comparison to that of single-exercise programs. Knee flexion angle was improved following integrated training (combined balance and strength exercises or combined plyometric and strength exercises). Similarly, external knee flexion moment was improved following integrated training consisting of balance, plyometric, and strength exercises. VGRF was improved when incorporating supervision with instruction and

  9. Effect of antagonist muscle fatigue on knee extension torque.

    PubMed

    Beltman, J G M; Sargeant, A J; Ball, D; Maganaris, C N; de Haan, A

    2003-09-01

    The effect of hamstring fatigue on knee extension torque was examined at different knee angles for seven male subjects. Before and after a dynamic flexion fatigue protocol (180 degrees s(-1), until dynamic torque had declined by 50%), maximal voluntary contraction extension torque was measured at four knee flexion angles (90 degrees, 70 degrees, 50 degrees and 30 degrees ). Maximal torque generating capacity and voluntary activation of the quadriceps muscle were determined using electrical stimulation. Average rectified EMG of the biceps femoris was determined. Mean dynamic flexion torque declined by 48+/-11%. Extensor maximal voluntary contraction torque, maximal torque generating capacity, voluntary activation and average rectified EMG at the four knee angles were unaffected by the hamstring fatigue protocol. Only at 50 degrees knee angle was voluntary activation significantly lower (15.7%) after fatigue ( P<0.05). In addition, average rectified EMG before fatigue was not significantly influenced by knee angle. It was concluded that a fatigued hamstring muscle did not increase the maximal voluntary contraction extension torque and knee angle did not change coactivation. Three possible mechanisms may explain the results: a potential difference in recruited fibre populations in antagonist activity compared with the fibres which were fatigued in the protocol, a smaller loss in isometric torque generating capacity of the hamstring muscle than was expected from the dynamic measurements and/or a reduction in voluntary activation.

  10. External knee joint design based on normal motion.

    PubMed

    Walker, P S; Kurosawa, H; Rovick, J S; Zimmerman, R A

    1985-01-01

    There are several advantages to accurate reproduction of knee motion in an external joint assembly such as a knee brace: reduction of pistoning forces, better ligament protection, kinematic compatability. The geometry and kinematics of the normal human knee were studied and the results applied to external joint design. Geometrically, the posterior portions of the femoral condyles were found to be spherical in shape. These spherical surfaces are projected in sagittal plane radiographs as circles with center points coincident with those of the spheres. A line connecting these centers defines an axis system and enables three-dimensional orientation of the femur on the tibia to be determined using sagittal-plane radiographs. Knee kinematics was determined as a function of flexion angle for 14 fresh cadavers and 8 volunteers. Results were in the form of eulerian rotations and displacements. The data were normalized to the size of the average knee and the results from the 22 trials were averaged. The most obvious motion was internal rotation of the tibia with flexion; however, varus rotation and posterior translation of the origin were also evident. An external joint system was then designed to mimic "average" knee motion during flexion. The joints have been incorporated into a knee brace, and clinical evaluation has begun. Other applications include cast bracing and hinge distraction.

  11. The influence of posterior tibial slope changes on joint gap and range of motion in unicompartmental knee arthroplasty.

    PubMed

    Takayama, Koji; Matsumoto, Tomoyuki; Muratsu, Hirotsugu; Ishida, Kazunari; Araki, Daisuke; Matsushita, Takehiko; Kuroda, Ryosuke; Kurosaka, Masahiro

    2016-06-01

    The effect of posterior slope on joint gap in unicompartmental knee arthroplasty (UKA) has yet to be quantified. The purpose of this study was to quantify the effect of the tibial slope on the joint component gap and postoperative range of motion in UKA. Forty consecutive patients were prospectively enrolled. The correlation between the tibial slope changes and the component gap, the component gap difference between flexion angles, the postoperative extension or flexion angles was examined. The correlation of joint looseness with tibial slope changes and postoperative extension angle was also examined. Increased tibial slope positively correlated with the differences between the component gap at 90° and 10°, 120° and 10°, or 135° and 10° knee flexion angle. Although tibial slope change did not affect postoperative flexion angle, increased tibial slope reduced postoperative extension angle. Moreover, increased tibial slope resulted in decreased joint looseness during 10° of knee flexion and decreased joint looseness during 10° of knee flexion resulted in reduced postoperative extension angle. Increased tibial slope resulted in tight component gap at knee extension compared with that at knee flexion. Furthermore, tight component gap at extension lead to decreased postoperative extension angle. These results indicate that an individual anatomical tibial slope should be considered when tibial sagittal osteotomy was performed and increasing tibial slope should be avoided to achieve full extension angle after UKA. II. Copyright © 2016. Published by Elsevier B.V.

  12. Verification of predicted knee replacement kinematics during simulated gait in the Kansas knee simulator.

    PubMed

    Halloran, Jason P; Clary, Chadd W; Maletsky, Lorin P; Taylor, Mark; Petrella, Anthony J; Rullkoetter, Paul J

    2010-08-01

    Evaluating total knee replacement kinematics and contact pressure distributions is an important element of preclinical assessment of implant designs. Although physical testing is essential in the evaluation process, validated computational models can augment these experiments and efficiently evaluate perturbations of the design or surgical variables. The objective of the present study was to perform an initial kinematic verification of a dynamic finite element model of the Kansas knee simulator by comparing predicted tibio- and patellofemoral kinematics with experimental measurements during force-controlled gait simulation. A current semiconstrained, cruciate-retaining, fixed-bearing implant mounted in aluminum fixtures was utilized. An explicit finite element model of the simulator was developed from measured physical properties of the machine, and loading conditions were created from the measured experimental feedback data. The explicit finite element model allows both rigid body and fully deformable solutions to be chosen based on the application of interest. Six degrees-of-freedom kinematics were compared for both tibio- and patellofemoral joints during gait loading, with an average root mean square (rms) translational error of 1.1 mm and rotational rms error of 1.3 deg. Model sensitivity to interface friction and damping present in the experimental joints was also evaluated and served as a secondary goal of this paper. Modifying the metal-polyethylene coefficient of friction from 0.1 to 0.01 varied the patellar flexion-extension and tibiofemoral anterior-posterior predictions by 7 deg and 2 mm, respectively, while other kinematic outputs were largely insensitive.

  13. Intraoperative passive knee kinematics during total knee arthroplasty surgery.

    PubMed

    Young, Kathryn L; Dunbar, Michael J; Richardson, Glen; Astephen Wilson, Janie L

    2015-11-01

    Surgical navigation systems for total knee arthroplasty (TKA) surgery are capable of capturing passive three-dimensional (3D) angular joint movement patterns intraoperatively. Improved understanding of patient-specific knee kinematic changes between pre and post-implant states and their relationship with post-operative function may be important in optimizing TKA outcomes. However, a comprehensive characterization of the variability among patients has yet to be investigated. The objective of this study was to characterize the variability within frontal plane joint movement patterns intraoperatively during a passive knee flexion exercise. Three hundred and forty patients with severe knee osteoarthritis (OA) received a primary TKA using a navigation system. Passive kinematics were captured prior to (pre-implant), and after prosthesis insertion (post-implant). Principal component analysis (PCA) was used to capture characteristic patterns of knee angle kinematics among patients, to identify potential patient subgroups based on these patterns, and to examine the subgroup-specific changes in these patterns between pre- and post-implant states. The first four extracted patterns explained 99.9% of the diversity within the frontal plane angle patterns among the patients. Post-implant, the magnitude of the frontal plane angle shifted toward a neutral mechanical axis in all phenotypes, yet subtle pattern (shape of curvature) features of the pre-implant state persisted.

  14. Forward lunge knee biomechanics before and after partial meniscectomy.

    PubMed

    Hall, Michelle; Nielsen, Jonas Høberg; Holsgaard-Larsen, Anders; Nielsen, Dennis Brandborg; Creaby, Mark W; Thorlund, Jonas Bloch

    2015-12-01

    Patients following meniscectomy are at increased risk of developing knee osteoarthritis in the tibiofemoral compartment and at the patellofemoral joint. As osteoarthritis is widely considered a mechanical disease, it is important to understand the potential effect of arthroscopic partial meniscectomy (APM) on knee joint mechanics. The purpose of this study was to evaluate changes in knee joint biomechanics during a forward lunge in patients with a suspected degenerative meniscal tear from before to three months after APM. Twenty-two patients (35-55 years old) with a suspected degenerative medial meniscal tear participated in this study. Three dimensional knee biomechanics were assessed on the injured and contralateral leg before and three months after APM. The visual analogue scale was used to assess knee pain and the Knee Injury Osteoarthritis Outcome Score was used to assess sport/recreation function and knee-related confidence before and after APM. The external peak knee flexion moment reduced in the APM leg compared to the contralateral leg (mean difference (95% CI)) -1.08 (-1.80 to -0.35) (Nm/(BW × HT)%), p = 0.004. Peak knee flexion angle also reduced in the APM leg compared to the contralateral leg -3.94 (-6.27 to -1.60) degrees, p = 0.001. There was no change in knee pain between the APM leg and contralateral leg (p=0.118). Self-reported sport/recreation function improved (p = 0.004). Although patients self-reported less difficulty during strenuous tasks following APM, patients used less knee flexion, a strategy that may limit excessive patellar loads during forward lunge in the recently operated leg. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. A kinetic and kinematic analysis of the effect of stochastic resonance electrical stimulation and knee sleeve during gait in osteoarthritis of the knee.

    PubMed

    Collins, Amber; Blackburn, Troy; Olcott, Chris; Jordan, Joanne M; Yu, Bing; Weinhold, Paul

    2014-02-01

    Extended use of knee sleeves in populations at risk for knee osteoarthritis progression has shown functional and quality of life benefits; however, additional comprehensive kinematic and kinetic analyses are needed to determine possible physical mechanisms of these benefits which may be due to the sleeve's ability to enhance knee proprioception. A novel means of extending these enhancements may be through stochastic resonance stimulation. Our goal was to determine whether the use of a knee sleeve alone or combined with stochastic resonance electrical stimulation improves knee mechanics in knee osteoarthritis. Gait kinetics and kinematics were assessed in subjects with medial knee osteoarthritis when presented with four conditions: control1, no electrical stimulation/sleeve, 75% threshold stimulation/sleeve, and control2. An increase in knee flexion angle throughout stance and a decrease in flexion moment occurring immediately after initial contact were seen in the stimulation/sleeve and sleeve alone conditions; however, these treatment conditions did not affect the knee adduction angle and internal knee abduction moment during weight acceptance. No differences were found between the sleeve alone and the stochastic resonance with sleeve conditions. A knee sleeve can improve sagittal-plane knee kinematics and kinetics, although adding the current configuration of stochastic resonance did not enhance these effects.

  16. Is latero-medial patellar mobility related to the range of motion of the knee joint after total knee arthroplasty?

    PubMed

    Ota, Susumu; Nakashima, Takeshi; Morisaka, Ayako; Omachi, Takaaki; Ida, Kunio; Kawamura, Morio

    2010-12-01

    Diminished range of motion (ROM) of the knee joint after total knee arthroplasty (TKA) is thought to be related to reduced patellar mobility. This has not been confirmed clinically due to a lack of quantitative methods adequate for measuring patellar mobility. We investigated the relationship between patellar mobility by a reported quantitative method and knee joint ROM after TKA. Forty-nine patients [osteoarthritis--OA: 29 knees; rheumatoid arthritis--RA: 20 knees] were examined after TKA. Respective medial and lateral patellar mobility was measured 1 and 6 months postoperatively using a patellofemoral arthrometer (PFA). Knee joint ROM was also measured in each of those 2 sessions. Although the flexion and extension of the knee joints improved significantly from 1 to 6 months after TKA, the medial and lateral patellar displacements (LPDs) failed to improve during that same period. Moreover, only the changes in knee flexion and medial patellar displacement (MPD) between the two sessions were positively correlated (r = 0.31, p < 0.05). However, our findings demonstrated that medial and lateral patellar mobility had no sufficient longitudinal relationship with knee ROM after TKA.

  17. Highly conforming polyethylene inlays reduce the in vivo variability of knee joint kinematics after total knee arthroplasty.

    PubMed

    Daniilidis, Kiriakos; Skwara, Adrian; Vieth, Volker; Fuchs-Winkelmann, Susanne; Heindel, Walter; Stückmann, Volker; Tibesku, Carsten O

    2012-08-01

    The use of highly conforming polyethylene inlays in total knee arthroplasty (TKA) provides improved anteroposterior stability. The aim of this fluoroscopic study was to investigate the in vivo kinematics during unloaded and loaded active extension with a highly conforming inlay and a flat inlay after cruciate retaining (CR) total knee arthroplasty (TKA). Thirty one patients (50 knees) received a fixed-bearing cruciate retaining total knee arthroplasty (Genesis II, Smith & Nephew, Schenefeld, Germany) for primary knee osteoarthritis. Twenty two of them received a flat polyethylene inlay (PE), nine a deep dished PE and 19 were in the control group (physiological knees). The mean age at the time of surgery was 62 years. Dynamic examination with fluoroscopy was performed to assess the "patella tendon angle" in relation to the knee flexion angle (measure of anteroposterior translation) and the "kinematic index" (measure of reproducibility). Fluoroscopy was performed under active extension and flexion, during unloaded movement, and under full weight bearing, simulated by step climbing. No significant difference was observed between both types of polyethylene inlay designs and the physiological knee during unloaded movement. Anteroposterior (AP) instability was found during weight-bearing movement. The deep-dish inlay resulted in lower AP translation and a non-physiological rollback. Neither inlay types could restore physiological kinematics of the knee. Despite the fact that deep dished inlays reduce the AP translation, centralisation of contact pressure results in non-physiological rollback. The influence of kinematic pattern variability on clinical results warrants further investigation.

  18. Position controlled Knee Rehabilitation Orthotic Device for Patients after Total Knee Replacement Arthroplasty

    NASA Astrophysics Data System (ADS)

    Wannaphan, Patsiri; Chanthasopeephan, Teeranoot

    2016-11-01

    Knee rehabilitation after total knee replacement arthroplasty is essential for patients during their post-surgery recovery period. This study is about designing one degree of freedom knee rehabilitation equipment to assist patients for their post-surgery exercise. The equipment is designed to be used in sitting position with flexion/extension of knee in sagittal plane. The range of knee joint motion is starting from 0 to 90 degrees angle for knee rehabilitation motion. The feature includes adjustable link for different human proportions and the torque feedback control at knee joint during rehabilitation and the control of flexion/extension speed. The motion of the rehabilitation equipment was set to move at low speed (18 degrees/sec) for knee rehabilitation. The rehabilitation link without additional load took one second to move from vertical hanging up to 90° while the corresponding torque increased from 0 Nm to 2 Nm at 90°. When extra load is added, the link took 1.5 seconds to move to 90° The torque is then increased from 0 Nm to 4 Nm. After a period of time, the speed of the motion can be varied. User can adjust the motion to 40 degrees/sec during recovery activity of the knee and users can increase the level of exercise or motion up to 60 degrees/sec to strengthen the muscles during throughout their rehabilitation program depends on each patient. Torque control is included to prevent injury. Patients can use the equipment for home exercise to help reduce the number of hospital visit while the patients can receive an appropriate therapy for their knee recovery program.

  19. A multicenter analysis of axial femorotibial rotation after total knee arthroplasty.

    PubMed

    Dennis, Douglas A; Komistek, Richard D; Mahfouz, Mohamed R; Walker, Scott A; Tucker, Abby

    2004-11-01

    A multicenter analysis was done to determine in vivo femorotibial axial rotation magnitudes and patterns in 1,027 knees (normal knees, nonimplanted ACL-deficient knees, and multiple designs of total knee arthroplasty). All knees were analyzed using fluoroscopy and a three-dimensional computer model-fitting technique during a deep knee bend and/or gait. Normal knees showed 16.5 degrees and 5.7 degrees of internal tibial rotation during a deep knee bend and gait, respectively. Rotation magnitudes and the percent having normal axial rotation patterns decreased in all total knee arthroplasty groups during a deep knee bend. During gait, all knee arthroplasty groups had similar rotational patterns (limited magnitudes). Average axial rotational magnitudes in gait and a deep knee bend were similar among major implant categories (ie, fixed-bearing versus mobile-bearing, etc). Average values in normal knees and ACL-retaining total knee arthroplasty patients (16.5 degrees and 8.1 degrees , respectively) were higher than in groups in which the ACL was absent (< 4.0 degrees ). All total knee arthroplasty groups had at least 19% of patients have a reverse axial rotational pattern during a deep knee bend and at least 31% during gait. Normal axial rotation patterns are essential for good patellar tracking, reduction of patellofemoral shear forces, and maximization of knee flexion.

  20. Changes in knee kinematics following total knee arthroplasty.

    PubMed

    Akbari Shandiz, Mohsen; Boulos, Paul; Saevarsson, Stefan Karl; Yoo, Sam; Miller, Stephen; Anglin, Carolyn

    2016-04-01

    Total knee arthroplasty (TKA) changes the knee joint in both intentional and unintentional, known and unknown, ways. Patellofemoral and tibiofemoral kinematics play an important role in postoperative pain, function, satisfaction and revision, yet are largely unknown. Preoperative kinematics, postoperative kinematics or changes in kinematics may help identify causes of poor clinical outcome. Patellofemoral kinematics are challenging to record since the patella is obscured by the metal femoral component in X-ray and moves under the skin. The purpose of this study was to determine the kinematic degrees of freedom having significant changes and to evaluate the variability in individual changes to allow future study of patients with poor clinical outcomes. We prospectively studied the 6 degrees of freedom patellofemoral and tibiofemoral weightbearing kinematics, tibiofemoral contact points and helical axes of rotation of nine subjects before and at least 1 year after total knee arthroplasty using clinically available computed tomography and radiographic imaging systems. Normal kinematics for healthy individuals were identified from the literature. Significant differences existed between pre-TKA and post-TKA kinematics, with the post-TKA kinematics being closer to normal. While on average the pre-total knee arthroplasty knees in this group displayed no pivoting (only translation), individually only five knees displayed this behaviour (of these, two showed lateral pivoting, one showed medial pivoting and one showed central pivoting). There was considerable variability postoperatively as well (five central, two lateral and two medial pivoting). Both preop and postop, flexion behaviour was more hinge-like medially and more rolling laterally. Helical axes were more consistent postop for this group. An inclusive understanding of the pre-TKA and post-TKA kinematics and changes in kinematics due to total knee arthroplasty could improve implant design, patient diagnosis and

  1. In vivo kinematics of a robot-assisted uni- and multi-compartmental knee arthroplasty.

    PubMed

    Watanabe, Toshifumi; Abbasi, Ali Z; Conditt, Michael A; Christopher, Jennifer; Kreuzer, Stefan; Otto, Jason K; Banks, Scott A

    2014-07-01

    There is great interest in providing reliable and durable treatments for one- and two-compartment arthritic degeneration of the cruciate-ligament intact knee. One approach is to resurface only the diseased compartments with discrete unicompartmental components, retaining the undamaged compartment(s). However, placing multiple small implants into the knee presents a greater surgical challenge than total knee arthroplasty, so it is not certain that the natural knee mechanics can be maintained or restored. The goal of this study was to determine whether near-normal knee kinematics can be obtained with a robot-assisted multi-compartmental knee arthroplasty. Thirteen patients with 15 multi-compartmental knee arthroplasties using haptic robotic-assisted bone preparation were involved in this study. Nine subjects received a medial unicompartmental knee arthroplasty (UKA), three subjects received a medial UKA and patellofemoral (PF) arthroplasty, and three subjects received medial and lateral bi-unicondylar arthroplasty. Knee motions were recorded using video-fluoroscopy an average of 13 months (6-29 months) after surgery during stair and kneeling activities. The three-dimensional position and orientation of the implant components were determined using model-image registration techniques. Knee kinematics during maximum flexion kneeling showed femoral external rotation and posterior lateral condylar translation. All knees showed femoral external rotation and posterior condylar translation with flexion during the step activity. Knees with medial UKA and PF arthroplasty showed the most femoral external rotation and posterior translation, and knees with bicondylar UKA showed the least. Knees with accurately placed uni- or bi-compartmental arthroplasty exhibited stable knee kinematics consistent with intact and functioning cruciate ligaments. The patterns of tibiofemoral motion were more similar to natural knees than commonly has been observed in knees with total knee

  2. The effect of a dynamic PCL brace on patellofemoral compartment pressures in PCL-and PCL/PLC-deficient knees.

    PubMed

    Welch, Tyler; Keller, Thomas; Maldonado, Ruben; Metzger, Melodie; Mohr, Karen; Kvitne, Ronald

    2017-12-01

    The natural history of posterior cruciate ligament (PCL) deficiency includes the development of arthrosis in the patellofemoral joint (PFJ). The purpose of this biomechanical study was to evaluate the hypothesis that dynamic bracing reduces PFJ pressures in PCL- and combined PCL/posterolateral corner (PLC)-deficient knees. Controlled Laboratory Study. Eight fresh frozen cadaveric knees with intact cruciate and collateral ligaments were included. PFJ pressures and force were measured using a pressure mapping system via a lateral arthrotomy at knee flexion angles of 30°, 60°, 90°, and 120° in intact, PCL-deficient, and PCL/PLC-deficient knees under a combined quadriceps/hamstrings load of 400 N/200 N. Testing was then repeated in PCL- and PCL/PLC-deficient knees after application of a dynamic PCL brace. Application of a dynamic PCL brace led to a reduction in peak PFJ pressures in PCL-deficient knees. In addition, the brace led to a significant reduction in peak pressures in PCL/PLC-deficient knees at 60°, 90°, and 120° of flexion. Application of the dynamic brace also led to a reduction in total PFJ force across all flexion angles for both PCL- and PCL/PLC-deficient knees. Dynamic bracing reduces PFJ pressures in PCL- and combined PCL/PLC-deficient knees, particularly at high degrees of knee flexion.

  3. The anterior cruciate ligament provides resistance to externally applied anterior tibial force but not to internal rotational torque during simulated weight-bearing flexion.

    PubMed

    Wünschel, Markus; Müller, Otto; Lo, JiaHsuan; Obloh, Christian; Wülker, Nikolaus

    2010-11-01

    We investigated knee kinematics during simulated weight-bearing flexion and determined the effect of 3 different parameters of external tibial loading on the kinematics of the anterior cruciate ligament (ACL)-intact and ACL-deficient knee. Ten human knee specimens were mounted on a dynamic knee simulator, and weight-bearing muscle-loaded knee flexions were simulated while a robotic/universal force sensor system was used to provide external tibial loads during the motion. Three different loading conditions were simulated: partial body weight only, an additional 50 N of anterior tibial force (ATD), or an additional 5 Nm of internal rotational tibial torque (IRT). After arthroscopic transection of the ACL, these 3 trials were repeated. The kinematics were measured with an ultrasonic measuring system for 3-dimensional motion analysis, and different loading and knee conditions were examined. When the ACL was intact, ATD and IRT barely changed the anterior tibial translation. However, in the absence of the ACL, ATD significantly increased the anterior tibial translation by 5 mm whereas IRT did not. The application of IRT increased the internal tibial rotation of ACL-intact knees, but there was no difference in the internal rotation before and after transection of the ACL. Regardless of ACL status, the difference in the anterior tibial translation and the internal tibial rotation across different external tibial loadings was greater at lower flexion angles and gradually diminished with increasing flexion angles. We established an experimental protocol, incorporating a dynamic knee simulator and a robotic/universal force sensor system, to successfully measure the kinematics of the knee joint while applying external forces in weight-bearing flexion. Our findings suggest that, in muscle-loaded knee flexion, the ACL provides substantial resistance to externally applied ATD but not to IRT. Information from this study allows us to better understand the function of the ACL and

  4. Jumper's Knee (Patellar Tendonitis)

    MedlinePlus

    ... Surgery? A Week of Healthy Breakfasts Shyness Jumper's Knee KidsHealth > For Teens > Jumper's Knee A A A ... continued damage to the knee. How Does the Knee Work? To understand how jumper's knee happens, it ...

  5. Stress fracture of the proximal fibula after total knee arthroplasty.

    PubMed

    Vaish, Abhishek; Vaishya, Raju; Agarwal, Amit Kumar; Vijay, Vipul

    2016-04-22

    We report a rare case of proximal fibular fatigue fracture developing 14 years after total knee arthroplasty in a known case of rheumatoid arthritis. A valgus deformity of the knee can put abnormal stress on the upper fibula leading to its failure. We believe that, as the fibula acts as an important lateral strut, its disruption due to a fracture led to rapid progress of the valgus deformity of the knee in this patient.

  6. Do knee concentric and eccentric strength and sagittal-plane knee joint biomechanics differ between jumpers and non-jumpers in landing?

    PubMed

    Wu, Xie; Zhang, Songning; Liu, Yu; Zhang, Dongbin; Xie, Bin

    2013-12-01

    The purpose of this study was to investigate the differences of knee concentric and eccentric strength and impact related knee biomechanics between jumpers and non-jumpers during step-off landing tasks. Ten male college swimming athletes (non-jumpers) and 10 track and volleyball athletes (jumpers) were recruited to participate in two test sessions: a muscle strength testing session of concentric and eccentric extension for dominant knee joint at 60°/s and 180°/s and a landing testing session. The participants performed five trials of step-off landing in each of four conditions: soft and stiff landing from 0.4m and 0.6m landing heights. The three-dimensional kinematics and ground reaction force were recorded simultaneously during step-off landing conditions. The results showed that the jumpers had significantly greater peak knee eccentric extension and concentric flexion torques compared to the non-jumpers. No significant group effects were found for peak vertical ground reaction force and knee range of motion during landing. The jumpers had significantly greater knee contact flexion angle, maximum knee flexion angle and initial knee extension moment compared to the non-jumpers. These results suggest that these athletes adopted a favorable impact attenuation strategy that is related to the greater knee eccentric muscle strength and training. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Improvements in knee biomechanics during walking are associated with increased physical activity after total knee arthroplasty.

    PubMed

    Arnold, John B; Mackintosh, Shylie; Olds, Timothy S; Jones, Sara; Thewlis, Dominic

    2015-12-01

    Total knee arthroplasty (TKA) in people with knee osteoarthritis increases knee-specific and general physical function, but it has not been established if there is a relationship between changes in these elements of functional ability. This study investigated changes and relationships between knee biomechanics during walking, physical activity, and use of time after TKA. Fifteen people awaiting TKA underwent 3D gait analysis before and six months after surgery. Physical activity and use of time were determined in free-living conditions from a high resolution 24-h activity recall. After surgery, participants displayed significant improvements in sagittal plane knee biomechanics and improved their physical activity profiles, standing for 105 more minutes (p=0.001) and performing 64 min more inside chores on average per day (p=0.008). Changes in sagittal plane knee range of motion (ROM) and peak knee flexion positively correlated with changes in total daily energy expenditure, time spent undertaking moderate to vigorous physical activity, inside chores and passive transport (r=0.52-0.66, p=0.005-0.047). Restoration of knee function occurs in parallel and is associated with improvements in physical activity and use of time after TKA. Increased functional knee ROM is required to support improvements in total and context specific physical activity. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  8. EFFECTS OF THE GENIUM MICROPROCESSOR KNEE SYSTEM ON KNEE MOMENT SYMMETRY DURING HILL WALKING

    PubMed Central

    Highsmith, M. Jason; Klenow, Tyler D.; Kahle, Jason T.; Wernke, Matthew M.; Carey, Stephanie L.; Miro, Rebecca M.; Lura, Derek J.

    2016-01-01

    Use of the Genium microprocessor knee (MPK) system reportedly improves knee kinematics during walking and other functional tasks compared to other MPK systems. This improved kinematic pattern was observed when walking on different hill conditions and at different speeds. Given the improved kinematics associated with hill walking while using the Genium, a similar improvement in the symmetry of knee kinetics is also feasible. The purpose of this study was to determine if Genium MPK use would reduce the degree of asymmetry (DoA) of peak stance knee flexion moment compared to the C-Leg MPK in transfemoral amputation (TFA) patients. This study used a randomized experimental crossover of TFA patients using Genium and C-Leg MPKs (n = 20). Biomechanical gait analysis by 3D motion tracking with floor mounted force plates of TFA patients ambulating at different speeds on 5° ramps was completed. Knee moment DoA was significantly different between MPK conditions in the slow and fast uphill as well as the slow and self-selected downhill conditions. In a sample of high-functioning TFA patients, Genium knee system accommodation and use improved knee moment symmetry in slow speed walking up and down a five degree ramp compared with C-Leg. Additionally, the Genium improved knee moment symmetry when walking downhill at comfortable speed. These results likely have application in other patients who could benefit from more consistent knee function, such as older patients and others who have slower walking speeds. PMID:28066523

  9. EFFECTS OF THE GENIUM MICROPROCESSOR KNEE SYSTEM ON KNEE MOMENT SYMMETRY DURING HILL WALKING.

    PubMed

    Highsmith, M Jason; Klenow, Tyler D; Kahle, Jason T; Wernke, Matthew M; Carey, Stephanie L; Miro, Rebecca M; Lura, Derek J

    2016-09-01

    Use of the Genium microprocessor knee (MPK) system reportedly improves knee kinematics during walking and other functional tasks compared to other MPK systems. This improved kinematic pattern was observed when walking on different hill conditions and at different speeds. Given the improved kinematics associated with hill walking while using the Genium, a similar improvement in the symmetry of knee kinetics is also feasible. The purpose of this study was to determine if Genium MPK use would reduce the degree of asymmetry (DoA) of peak stance knee flexion moment compared to the C-Leg MPK in transfemoral amputation (TFA) patients. This study used a randomized experimental crossover of TFA patients using Genium and C-Leg MPKs (n = 20). Biomechanical gait analysis by 3D motion tracking with floor mounted force plates of TFA patients ambulating at different speeds on 5° ramps was completed. Knee moment DoA was significantly different between MPK conditions in the slow and fast uphill as well as the slow and self-selected downhill conditions. In a sample of high-functioning TFA patients, Genium knee system accommodation and use improved knee moment symmetry in slow speed walking up and down a five degree ramp compared with C-Leg. Additionally, the Genium improved knee moment symmetry when walking downhill at comfortable speed. These results likely have application in other patients who could benefit from more consistent knee function, such as older patients and others who have slower walking speeds.

  10. [Modern unicondylar knee arthroplasty. Tips and tricks].

    PubMed

    von Knoch, F; Munzinger, U

    2014-05-01

    Unicondylar knee arthroplasty (UKA) is an established therapeutic option for advanced medial or lateral gonarthrosis. The cornerstones of a successful UKA, careful patient selection, preoperative planning and precise operation technique, are discussed in this overview article. In contrast to total knee arthroplasty, UKA allows preservation of the contralateral and patellofemoral compartments as well as the cruciate ligaments and is often associated with rapid postoperative recovery, improved knee kinematics and knee function. However, UKA is technically very demanding. High revision rates have been reported in particular with widespread application, according to national joint replacement registries. Successful UKA relies on meticulous patient selection, preoperative planning and surgical technique. It is justified to broaden classic UKA indications. In medial and lateral UKA three types of mechanical varus-valgus deformity can be encountered: type 1 (isolated intraarticular deformity), type 2 (pronounced deformity due to extraarticular varus deformity in medial UKA or valgus deformity in lateral UKA), type 3 (reduced deformity due to extraarticular valgus deformity in medial UKA or varus deformity in lateral UKA). We believe these deformities should be addressed accordingly with surgical technique.

  11. Improving lensing cluster mass estimate with flexion

    NASA Astrophysics Data System (ADS)

    Cardone, V. F.; Vicinanza, M.; Er, X.; Maoli, R.; Scaramella, R.

    2016-11-01

    Gravitational lensing has long been considered as a valuable tool to determine the total mass of galaxy clusters. The shear profile, as inferred from the statistics of ellipticity of background galaxies, allows us to probe the cluster intermediate and outer regions, thus determining the virial mass estimate. However, the mass sheet degeneracy and the need for a large number of background galaxies motivate the search for alternative tracers which can break the degeneracy among model parameters and hence improve the accuracy of the mass estimate. Lensing flexion, i.e. the third derivative of the lensing potential, has been suggested as a good answer to the above quest since it probes the details of the mass profile. We investigate here whether this is indeed the case considering jointly using weak lensing, magnification and flexion. We use a Fisher matrix analysis to forecast the relative improvement in the mass accuracy for different assumptions on the shear and flexion signal-to- noise (S/N) ratio also varying the cluster mass, redshift, and ellipticity. It turns out that the error on the cluster mass may be reduced up to a factor of ˜2 for reasonable values of the flexion S/N ratio. As a general result, we get that the improvement in mass accuracy is larger for more flattened haloes, but it extracting general trends is difficult because of the many parameters at play. We nevertheless find that flexion is as efficient as magnification to increase the accuracy in both mass and concentration determination.

  12. Deep flexion activity training in a patient with stroke using task-oriented exercise: a case report.

    PubMed

    Hariohm, K; Prakash, V

    2014-04-01

    Many individuals with stroke express desires to resume activities involving deep knee flexion, such as daily living, work-related, and sports activities. However, training methods for improving deep flexion activities have not commonly been reported in the stroke rehabilitation literature. The purpose of this case report is to describe the development of a task-oriented training program and demonstrate its use in improving deep flexion activities in an individual with sub-acute hemiplegia. The patient was a 55-year-old shoe salesman diagnosed with ischemic stroke 6 weeks before physical therapy evaluation. His primary concerns were functional activities that required deep flexion, such as the inability to squat and to maintain a squatting position in the Eastern toilet and difficulty in performing work-related activities (e.g. fitting shoes for customers while sitting on a low stool). We developed a task-oriented training program that specifically targeted deep flexion activities. The first phase of training consisted primarily of practicing sit-to-stand on a low stool and the second phase consisted of practicing squatting. After 6 weeks of intervention, the patient achieved more than the expected outcome on the Goal Attainment Scale (score = +2) for both primary goals and reported positive changes in social participation, such as visiting his friends and relatives and praying at the temple. The task-oriented deep flexion activity intervention was associated with positive changes in functional activity and social participation in a patient recovering from stroke.

  13. Reliability of digital compass goniometer in knee joint range of motion measurement.

    PubMed

    Yaikwawongs, Nammond; Limpaphayom, Noppachart; Wilairatana, Vajara

    2009-04-01

    To compare the reliability of range of motion measurement in the knee joint using a digital compass goniometer combined with inclinometer with standard range of motio