Influence of medial meniscectomy on tibiofemoral joint space width.

Objective: The aim of this study was to evaluate the influence of partial medial meniscectomy on tibiofemoral joint space width (JSW).

Design: Thirty-seven patients (mean age: 51 years), suffering from medial meniscal lesions, (post-traumatic (n=22) or degenerative (n=15)), and requiring arthroscopic partial meniscectomy, were enrolled in a prospective, controlled study. Bilateral weight-bearing radiographs in extended and flexed position were performed in the same Radiology Unit just before and 2 days after meniscectomy. During arthroscopy, the extent of meniscectomy was evaluated in percentage and medial chondropathy was quantified using the Société Française d'Arthroscopie (SFA) scoring system (SFA score: 0-100). Medial chondropathy was absent or mild (mean SFA score: 8+/-13). Meniscectomy removed an average of 61% of the posterior third of the medial meniscus, 51% of the middle third and 22% of the anterior third. Radiographs, before and after meniscectomy, were read singly and were analyzed by a single reader unaware of patient identity and date of radiographs. Medial JSW was measured at the narrowest point of the medial compartment using a 0.1mm graduated magnifying glass.

Results: Comparison of JSW before and after meniscectomy did not show any statistically significant difference (mm): 0.01+/-0.43 (p=0.83) and -0.05+/-0.56 (p=0.66) in the extended and flexed views, respectively.

Conclusion: This preliminary study suggests that partial medial meniscectomy does not influence tibiofemoral JSW on weight-bearing X-rays. Consequently, joint space narrowing appearing after partial meniscectomy should lead to seeking postmeniscectomy cartilage degradation rather than being attributed to removal of the meniscus.