Modular femoral head and liner exchange for the unstable total hip arthroplasty.

Outcomes of femoral head and nonconstrained liner exchange in treating hip instability were evaluated. Forty-eight modular component exchanges performed in 45 patients for recurrent hip dislocations were retrospectively reviewed. Mean follow-up was 4.7 years. Overall success rate was 73% (35/48 hips). Thirty-two (67%) of 48 hips experienced no further dislocations. Three patients had 1 dislocation each with no subsequent dislocations. Ten patients (13 hips) had additional surgery to stabilize their hips (27% failure rate). Demographic, clinical, and implant variables were not associated with outcome. Isolated modular component exchange can be successful in treating recurrent hip dislocations; however, a significant failure rate, not easily predicted, exists. This represents the largest series of modular head and nonconstrained liner exchange for hip dislocation (122/125).