THE POSTERIOR LIP AUGMENTATION DEVICE FOR RECURRENT DISLOCATION

Abstract

This study reports the outcome of using the Posterior Lip Augmentation Device (PLAD) for recurrent dislocation of total hip replacement. Twenty-seven patients (16 in Inverness, 11 in Leeds) were treated with the device. The indication for its use was recurrent dislocation of the hip in a patient who had a well-orientated and well-fixed cemented acetabular component. The patients had had between 2 and 14 dislocations before using the PLAD. 24 of the 27 patients had satisfactory control of the dislocations after surgery. The operation was found to be straightforward in most cases with few complications, although one case in the Inverness series has a partial sciatic nerve palsy which is recovering. Of the three failures, two had recurrent dislocation after the use of the PLAD. In one of these, in whom the dislocation followed acetabular reconstruction with impaction grafting, the cup also pulled out due to the semi-captive state after use of the PLAD. Both of these cases were treated by a Girdlestone excision arthroplasty. There was one final failure in whom there has been no further dislocation but following an abduction injury some four months after surgery, progressive cup loosening developed and he awaits revision of the cup. One patient complains of an occasional click in the hip joint and a broken screw is visible on x-ray but there has been no loss of position of the device and no further evidence of dislocation. Overall, we have found that this device gives satisfactory control of recurrent dislocations of the hip but the failures have stressed the need to ensure that the cup fixation is sound before inserting the device.