Modular revision for recurrent dislocation of primary or revision total hip arthroplasty

Two surgeons who used the same implants and surgical approach performed 23 revisions for recurrent dislocation of modular total hip arthroplasty (THA) with retention of components. For 17 primary hips, there was a mean of 3.8 (range, 2-10) dislocations before revision. Fifteen hips had exchange of the acetabular liner, 13 had a change in neck length, and 5 had a change in size of the femoral head. At a mean follow-up of 4 years (range, 2-7 years), 14 patients (82%) had no further dislocation, 1 had 1 additional dislocation, and 2 required additional surgery. For the 6 revision procedures, the mean number of dislocations was 3.8 (range, 2-10) before re-revision. Liner exchange was performed in 4 hips, neck length changed in 3 hips, and head size increased in 2 hips. At a mean follow-up of 3 years (range, 2-5 years), only 3 patients (50%) had no further dislocation, and 2 required additional surgery. Modular revision can be a successful method of treatment of recurrent dislocation after primary THA, but is much less successful after revision THA.