Flexion Deformity

Abstract

Knees with degenerative or rheumatoid arthritis may have associated intra-articular inflammation and effusion because of which they may assume a position of flexion in response to the pain and increased intra-articular pressure. Posterior femoral and tibial osteophytes along with those in the intercondylar notch in OA may enhance the deformity by tenting the posterior capsule or blocking full extension. This, in the long run, becomes a fixed flexion deformity, adding to the disability of the patient. Knee arthritis with a fixed flexion deformity interferes with ambulation causing increased energy expenditure, decreased stride length and velocity, decreased endurance and inability to stand for long periods. Flexion deformities are commonly encountered in knees with varus or valgus deformities. Isolated flexion deformities in knee arthritis are rare, although in some knees fixed flexion deformity may be the predominant deformity when compared to coronal plane deformities. It is estimated that flexion contractures may occur in up to 60 % of knees undergoing TKA. This chapter aims to discuss the management of fixed flexion deformities in TKA.