Background

Meniscal deficiency has been reported to increase contact pressures in the affected tibiofemoral joint, eventually leading to degenerative changes. Current surgical options include meniscal allograft transplantation and insertion of segmental meniscal scaffolds. Little is known about segmental meniscal allograft transplantation.

Purpose

To evaluate the effectiveness of segmental medial meniscus allograft transplantation in the setting of partial medial meniscectomy in restoring native knee loading characteristics in a human cadaveric model.

Study Design: Controlled laboratory study

Methods

Ten fresh frozen human cadaveric knees underwent central midbody medial meniscectomy and subsequent segmental medial meniscus allograft transplantation. Knees were potted and placed in a dynamic tensile testing machine and loaded to 1000 N for 20 seconds at 0, 30, 60, and 90 degrees flexion. Four conditions were tested: 1) intact medial meniscus; 2) deficient medial meniscus; 3) segmental medial meniscus transplant fixed with 7 meniscocapsular sutures; 4) segmental medial meniscus transplant fixed with 7 meniscocapsular sutures and 1 suture fixed through 2 bone tunnels. Submeniscal medial and lateral pressure-mapping sensors were used to assess mean contact pressure, peak contact pressure, mean contact area, and pressure mapping. Two-factor random-intercepts linear mixed-effects models compared pressure and contact area measurements among the 4 experimental conditions.

Results

The meniscal deficient state demonstrated significantly higher mean contact pressure than all other testing conditions (p <0.001 for all comparisons) and significantly smaller total contact area compared to all other testing conditions (p < 0.001 for all comparisons). There were no significant differences in mean contact pressure or total contact area between the intact, transplant, or transplant with tunnel groups. There were no significant differences in any outcome measure across all comparisons in the lateral compartment and no significant differences in center of pressure and relative pressure distribution across testing conditions.

Conclusion

Segmental medial meniscus allograft transplantation restored the medial compartment mean contact pressure and mean contact area to values measured in the intact medial compartment.

Clinical Relevance: Segmental medial meniscus transplantation may provide an alternative to full meniscal transplantation by addressing only the deficient portion of the meniscus with transplanted tissue. Additional work is required to validate long-term fixation strength and biologic integration.