Effects of bone shapes and ligaments attachements on to passive knee motions

Creating three dimensional dynamic human knee model and investigating the reasons of problems after surgical treatment are the subjects which has been studying by many investigators. The aim of the study was determining the primer structures which effect on passive movement on human knee joint. The tibio-femoral joint model was created by guidance of literature and then it is simulated by using ADAMS package. Some of the ligament bundles were seen to elongate negligibly. Therefore simulation was repeated by assuming these bundles as inextensible links. During the simulation contact points were traced. Contact forces were defined between the traces and tibial plateau and it was resimulated. As a result the anterior bundle of anterior, posterior cruciates and medial collateral ligaments (MCL) and deep portion of MCL played an important role on shaping the bones which form the knee joint. The ligament surgeries should be developed by considering the ligament bundle reconstructions to reduce the unwanted side effects after the surgery

Three-dimensional knee model: Constrained by isometric ligament bundles and experimentally obtained tibio-femoral contacts

The purpose of this study is to investigate the effect of anterior portion of anterior cruciate ligament, posterior cruciate ligament, anterior and deep portions of medial collateral ligament and the tibio-femoral articular contacts on passive knee motion. A well-accepted reference model for a normal tibio-femoral joint is reconstructed from the literature. The proposed three-dimensional dynamic tibio-femoral model includes the isometric fascicles, ligament bundles and irregularly shaped medial-lateral contact surfaces. With the approach we aim to analyze bone shape and ligament related abnormalities of knee kinematics. The rotations, translations and the contact forces during passive knee flexion were compared against a reference model and the results were found in close accordance. This study demonstrated that isometric ligament bundles play an important role in understanding the femur shape from contact points on tibia. Femoral condyles are not necessarily spherical. The surgical treatments should consider both ligament bundle lengths and contact surface geometries to achieve a problem free knee kinematics after a knee surgery. (C) 2007 Elsevier Ltd. All rights reserved

Suture anchor tenodesis in repair of distal Achilles tendon injuries

PubMed: 23412254Background: Distal Achilles tendon avulsions are in the form of either bony and nonbony avulsion of Achilles tendon from its calcaneal insertion. Methods: Four patients with distal Achilles tendon avulsions or ruptures which were treated with tendon to bone repair using suture anchors are presented here. Operated leg was immobilized in above-knee cast for 4 weeks while the patient walked non-weight-bearing. Then, cast was changed to below knee, and full weight-bearing was allowed. Patients underwent gait analysis minimum at first postoperative year. Results: Mean American Orthopedics Foot Ankle Society ankle/hindfoot score of patients at last visit was 88.75 (range 85-100), and Achilles tendon total rupture score was 77.75 (range 58-87). Mean passive dorsiflexion of injured ankles (14 ± 5) was lower than uninjured ankles (23 ± 9). All the kinematic parameters of gait analysis were comparable to the uninjured side. Maximum plantar flexion power of injured ankle was 1.40 W/kg, and this was significantly lower than the contralateral side value 2.38 W/kg; (P = 0.0143). Conclusions: There were no visually altered gait or problems in daily life. Suture anchor tenodesis technique of distal Achilles tendon avulsions was successful in achieving durable osteotendinous repairs. © 2012 Springer-Verlag France

Arthroscopic synovectomy in the treatment of functional ankle instability: Outcomes and gait analysis

Background Natural consequence of repetitive ankle sprains is the chronic ankle instability. Objective of this study was to clarify the gait patterns of functional ankle instability (FAI) patients after arthroscopic synovectomy, but also assessment of postoperative recovery. Patients and methods Arthroscopic synovectomy was performed to 14 FAI patients with history of unilateral repetitive ankle sprains, pain, and subjective sensation of instability. At a mean 54 months of follow-up (27-84), clinical assessment was conducted with respect to pain, number of ankle sprains, and American Orthopaedics Foot and Ankle Society (AOFAS) scores. Gait analysis was conducted to determine the temporospatial, kinetic and kinematic parameters at the last follow-up. Results Mean AOFAS scores increased from 68 (range 55-75) to 89 (range 77-100) points (P0.01). Among temporospatial parameters, only double support time showed a significant difference (P<0.01). All patients were satisfied from the procedure and returned to their previous activity level. Conclusion Improved long-term clinical results and scores were obtained in our patient group when compared with the preoperative scores. Also, three-dimensional gait analysis showed that the involved ankles demonstrate similar gait patterns to the uninvolved ankles in patients with FAI. © Springer-Verlag France 2014