Abstract
Abstract
Introduction
Previous research has shown that, notwithstanding ligament healing, properly selected MCL reconstruction can restore normal knee stability after MCL rupture. The hypothesis of this work was that it is possible to restore knee stability (particularly valgus and AMRI) with simplified and/or less-invasive MCL reconstruction methods.
Methods
Nine unpaired human knees were cleaned of skin and fat, then digitization screws and optical trackers were attached to the femur and tibia. A Polaris stereo camera measured knee kinematics across 0o-100o flexion when the knee was unloaded then with 90N anterior-posterior force, 9Nm varus-valgus moment, 5Nm internal-external rotation, and external+anterior (AMRI) loading. The test was conducted for the following knee conditions: intact, injured: transected superficial and deep MCL (sMCL and dMCL), and five reconstructions: (long sMCL, long sMCL+dMCL, dMCL, short sMCL+dMCL, short sMCL), all based on the medial epicondyle isometric point and using 8mm tape as a graft, with long sMCL 60mm below the joint line (anatomical), short sMCL 30mm, dMCL 10mm (anatomical).
Results
No significant changes were found in anterior or posterior translation, or varus at any stage. MCL deficiency caused increased valgus, external rotation and AMRI instabilities. All reconstructions restored valgus stability. The isolated long sMCL allowed residual external rotation and AMRI instability, while the short sMCL did stabilise AMRI. Both 2-strand reconstructions (dMCL+sMCL) restored stability.
Conclusion
All tested techniques, except long sMCL, restored valgus and AMRI stability of the knee. The single femoral tunnel is satisfactory for both the dMCL and sMCL grafts.
