Abstract
Purpose: Classically reported, degenerative femorotibial remodelling after meniscectomy results from different biomechanical mechanisms depending on the compartment considered. Occurring in the medial compartment, the most frequent situation, the lesions result from punctual contact compression of the cartilage. In the lateral compartment the mechanism involves increased relative instability of the structures controlling mobility. Lateral meniscectomy disrupts femorotibial kinetics of the meniscotibial gliding articulation leading to horizontal instability and subsequent generation of osteoarthritic degeneration which explains the development of lateral decompensations without genu valgum. Based on work by Grammont and Rudy, we proposed a method to limit this horizontal instability and transfer part of the stress to the medial compartment by medial translocation of the tibial tubercle.
Material and methods: Eighteen patients, mean age 44 years, underwent treatment for disabling degeneration without major misalignment (mean HKA 181°) a mean ten years after lateral meniscetomy. Degenerative remodelling of the lateral compartment was observed on the AP views in 30% of the knees and on the tangent views in 57% Five patients had early-stage lesions of the medial compartment and femoropatellar degradation was observed in 53%. Involvement of the lateral compartment was confirmed by systematic articular exploration and patellofemoral chondropathy was observed in eight knees. Translocation of the anterior tibial tubercle was associated with section of the lateral patellar wing in all knees associated with tension plasty medially.
Results: In 88% of the knees, the postoperative period was uneventful. Weight-bearing supported with a Zimmer cast was maintained for 21 days. Functional outcome was assessed at mean 28 months. Eleven patients had a new clinical and radiographic work-up (mean 34 months). Pain was improved in 88% of the knees, allowing sustained resumption of occupational activities at three months (four knees completely forgotten). Radiographically, at mean 34 months, the lateral cartilage lesions had stabilised with no impact on the medial compartment.
Discussion: In light of these results, we have decided to continue this therapeutic approach, reserving the technique for cases of symptomatic lateral decompensation in young subjects without major valgus malalignment.
Correspondence should be addressed to SOFCOT, 56 rue Boissonade, 75014 Paris, France.
