Dislocated Thompson hemiarthroplasty--the management of the recurrent dislocator.

Dislocation of a Thompson hemiarthroplasty of the hip is a serious complication with a high mortality rate. Previous papers have focused on surgical techniques to try and prevent dislocation. There is little in the literature on how to manage a patient after a dislocation. Patients with a dislocated Thompson hemiarthroplasty over a 5-year period from 1997 to March 2002 were analysed. Attempts were made to identify factors which may contribute to redislocation. Our strategies for preventing redislocation were evaluated. Of the 612 patients who received a Thompson hemiarthroplasty 23 patients (4%) dislocated. The average number of dislocations per patient was 2.4. Thirteen patients (57%) redislocated their prosthesis. Ten patients (43%) dislocated at least twice. Seven patients (30%) had either a total hip replacement, Girdlestone's procedure or the hip was left dislocated. Out of 15 patients fitted with an abduction brace 8 (60%) redislocated. Out of 8 patients treated with traction 6 (75%) redislocated. The 6-month mortality for patients suffering a dislocation was 7/23 (30%). If the prosthesis dislocates twice, the hip should be deemed unstable and consideration should be given to a revision procedure. Abduction braces and traction are ineffective in this condition and should be abandoned.