TOTAL KNEE ARTHROPLASTY FOR OSTEOARTHROSIS JUVENILIS: TECHNICAL DIFFICULTIES AND SOLUTIONS

Abstract

Purpose: We expose technical problems encountered for prosthesis replacement in osteoarthrosis juvenilis (OJ). The characteristic feature of this disease is early joint destruction during growth.

Material and methods: Total knee arthoplasty (TKA) was performed in 17 severely disabled patients (31 knees): Steinbrocker stage II=30%, stage III=30%, stage IV=40%. Mean age at operation was twenty years (14–29). Technical difficulties were related to the following combinations: 1) multidirectional malformations, generally in valgus (mean 16°, range 5–30°) in 30% of the knees associated with external rotation (mean 20°, range 5–50) and sagittal deformation with permanent flexion (mean 31°, range 5–60°) with external or posterior tibia dislocation; 2) limited joint motion: 71° (0–115°); 3) extraarticular deformations with permanent flexion or vicious hip rotation, tibial or femoral callus; 4) major condyle dysplasia due to growth deficiency (3/31 or necrosis (3/31); 5) low patella (100%) and subluxation; 6) weak bone and fragile skin related to corticosteroid therapy; 7) persistent growth cartilage in four patients. We tried to implant the most adapted prosthesis in each individual situation, favouring the least constrained implant possible.

Results: We used fifteen mobile plateau prostheses including five pure gliding TKA and ten posterostabilised TKA with a mobile plateau and 16 hinge prostheses with two rotators. Thirty of the 31 TKA were custom-made.

Discussion: Our different approaches enabled us to propose the following: correction of extra-articular deformations by TKA, after tenotomy and traction, or after concomitant osteotomy; primary approach after checking the vasculonervous bundle (popliteal sciatic); sub-periosteal dissection preserving the lateral ligaments searching to achieve ligament balance when possible in order to implant the least constrained implant possible; non-cemented implants, especially for “soft” or “fatty” bone; no patellar resurfacing when there is a risk of an overly thick low and subluxed patella.