Summary

Meniscal transplantation significantly improves functional outcomes in post-meniscectomy patients, although a high rate of meniscal extrusion is observed over time, potentially impacting the chondroprotective effects. No significant differences in joint space narrowing were found between transplanted and native menisci in the long term.

Abstract

Introduction

Meniscal injuries are common, especially in athletes, with a high incidence and prevalence. While younger patients are often treated with meniscal repair, older patients typically undergo meniscectomy, leading to post-meniscectomy syndrome characterized by persistent knee pain and early osteoarthritis. Meniscal transplantation has emerged as an effective treatment to alleviate symptoms and improve quality of life in patients who have undergone meniscectomy.

Objective

This study aimed to evaluate the functional outcomes in patients who underwent meniscal transplantation at the National Rehabilitation Institute “Luis Guillermo Ibarra Ibarra” between 2008 and 2018.

Methods

A retrospective, longitudinal, descriptive, observational, and analytical clinical study was conducted. The study included 12 patients, accounting for 13 knees, with a mean age of 33 years at the time of surgery and a follow-up period of 11.5 years. Functional outcomes were assessed using pre- and postoperative scores from various scales, including IKDC, SF-36, Lysholm, Tegner, KOOS, and Kujala. Radiographic and MRI assessments were used to evaluate joint space and meniscal extrusion, respectively.

Results

Of the 13 knees evaluated, 12 (92%) exhibited meniscal extrusion at an average of 5.55 ± 3.63 years postoperatively. There was a significant improvement in all functional scales from preoperative to the last follow-up. The preoperative IKDC subjective score improved from 44 to 59 postoperatively; the SF-36 physical component from 40 to 70; Lysholm score from 55 to 84; and KOOS sports and quality of life scores showed notable improvements as well. The MRI analysis showed that meniscal extrusion progressed over time, with an increase in the extrusion distance and a decrease in the MIMS score.

Discussion

The study found a significant improvement in functional outcomes post-meniscal transplantation, with most patients showing better scores in all evaluated scales. However, a high rate of meniscal extrusion (92%) was observed, which progressed over time. This extrusion was associated with a loss of chondroprotective effects, although no significant differences were found between compartments with transplanted menisci and native menisci regarding joint space at long-term follow-up.

Conclusion

Meniscal transplantation in patients following meniscectomy leads to significant improvements in functional outcomes, although it is frequently associated with progressive meniscal extrusion. This extrusion, while common, did not correlate with significant joint space narrowing when compared to native meniscus compartments. Further studies with larger samples and prospective designs are needed to better understand the long-term clinical implications of meniscal extrusion in this patient population.
Keywords: Meniscal injury, meniscectomy, meniscal allograft transplantation, chondroprotection, meniscal extrusion.