Summary

In this study we have shown the time zero mechanics of a partial transplant are non-inferior to that of a partial meniscectomy.

Abstract

Introduction

Treatment of meniscus injuries for competitive athletes is challenging given the high level of activity that must be restored. Some that seek tradition treatments such as partial meniscectomy are left unsatisfied by both the functional outcomes and the sensation post operatively. Advances in this area such as improved meniscus repair techniques and a recognition of the importance of preserving the meniscus have improved functional outcomes but there is still dissatisfaction from many top athletes in terms of sensation and proprioception which can be crucial for high level athleticism. Partial meniscus transplant is one potential alternative for athletes to restore the function and improve the sensation compared to a meniscectomy, since there is a possibility of engraftment of the allograph. For partial meniscus transplant to be a viable option however it must be able to restore the mechanics of the knee at least as well as a partial meniscectomy, the current industry standard. The intention of this study was to determine if the time zero mechanics after partial meniscus transplant is at least non-inferior to a partial meniscectomy.

Methods

Four fresh-frozen cadaver knees where used. Soft tissue was removed, and the extensor mechanism removed to facilitate access to the medial compartment. All intra and extra capsular ligaments were left intact. A medial femoral condyle osteotomy was performed to allow for interactive injury and repair of the meniscus as well as placement of the pressure sensors. The knee was tested intact, after a posteromedial horizontal partial tear was created via scalpel, after a standard partial meniscectomy and then after a donor matched for size and weight partial meniscus transplant. All tests were performed in full extension utilizing a uniaxial loading frame (MTS 30/G) under 200N, 400N and 800N of loading force. Changes in contact surface area and maximum contact force were evaluated.

Results

The contact area averaged across all 3 loading conditions for partial tear, partial meniscectomy, and partial transplant were 432 mm2, 477 mm2, and 422 mm2 respectively. While there was a statistically significant difference in the contact areas between the tear and the meniscectomy (p = 0.0001) there was no significant difference between the meniscectomy and transplant (p = 0.1272). The contact pressures of the medial compartment were found to be 616 kPa, 767 kPa, and 742 kPa for the same conditions. Again, there was statistically significant differences between the tear and meniscectomy (p = 0.0038) with no significant differences between the meniscectomy and the transplant (p = 0.5971). There was however now a statistically significant difference between the tear and transplant (p < 0.00001).

Conclusion

Partial meniscus transplant may be an option for treatment of partial meniscus tears in competitive athletes. In this study we have shown the time zero mechanics of a partial transplant are non-inferior to that of a partial meniscectomy. The theoretically possibility of engraftment and improved intra-joint proprioception in combination with the mechanics detailed in this study make partial meniscus transplant potentially even a superior option than partial meniscectomy alone.