[Total knee prosthesis and simultaneous corrective tibial osteotomy, for osteoarthritis and severe congenital tibia varum deformity].

INTRODUCTION: Restoration of the normal mechanical axis of the knee and balancing of the surrounding soft tissues have been shown to have an important bearing on the final outcome of total knee arthroplasty. In knees with severe congenital varum deformity these goals may be difficult to achieve.
MATERIAL AND METHODS: In four patients with osteoarthritis and severe congenital knee varum deformity of more than 15 degrees, we performed a high tibial valgus osteotomy with opening wedge, combined during the same procedure with total knee arthroplasty.
RESULTS: As correction of the extra-articular deformity was obtained by the osteotomy, in none of the cases it was necessary to perform extensive soft tissue release or advancement to restore alignment. Postoperative X-rays demonstrated restoration of the normal mechanical axis in three cases, but in one case the angular correction of the osteotomy was insufficient and we observed a 9 degrees residual varus deformity. DISCUSSION: The osteoarthritic knee must be mechanically realigned for any total knee arthroplasty to be successful in the long term. Most commonly angular deformities are manifestations of the arthritis process, but sometimes, like in congenital varus deformity of the tibia, part of the deformation can be extra-articular in origin. In these cases, restoring alignment and stability may be difficult to achieve. The association of high tibial valgus osteotomy with total knee arthroplasty permits the correction of the extra-articular deformity, by the osteotomy, without performing extensive soft tissue release, as would be needed in total knee arthroplasty alone.
CONCLUSION: Total knee arthroplasty associated with high tibial valgus osteotomy seems to be a technically satisfying alternative in patients with osteoarthritis and severe congenital varus deformity of the tibia.