Bridging massive acetabular defects with the triflange cup: 2- to 9-year results.

An unresolved issue in total hip arthroplasty is acetabular reconstruction when there is bone loss that results in pelvic discontinuity, that involves radiation-compromised bone stock, or that is significant enough to exceed the limits of jumbo hemispherical cups. Achieving pain relief and initial and long-term implant stability on host bone are the major goals of this type of reconstruction. Seventy-eight hips in 76 patients in whom a large acetabular defect was bridged using a custom-designed, flanged component were reviewed retrospectively. The preoperative deficiency was classified as a combined deficiency in 39 hips and as a pelvic discontinuity in the other 39 hips. Six patients died before a minimum 2 years followup. With five patients considered lost to followup, there were 67 hips in 65 patients with an average followup of 53 months (range, 24-107 months). No Triflange Cup has been removed. Harris hip scores improved from a preoperative mean of 33.3 points to a postoperative mean of 82.1 points. Radiographically there are two patients with incompletely healed discontinuities but both are asymptomatic. Re-operation for recurrent dislocation occurred in six patients (7.8%). The Triflange Cup offers an alternative method of repair that reliably provides pain relief, initial implant stability, potential long-term implant stability, and pelvic stability in cases of discontinuity.