Background

Acetabular revision THA with use of a large (jumbo) cup is an effective treatment for many cavitary and segmental peripheral bone defects. However, hip center elevation may occur with use of a jumbo cup owing to reaming superiorly and/or because of the increased diameter of the jumbo cup compared with the native acetabulum.

Questions/purposes

In our jumbo cup revision THAs, we attempted to avoid hip center elevation by placing the inferior edge of the cup at the inferior acetabulum. In this study, we asked (1) how much of an elevation in the hip center is observed radiographically with use of jumbo cups, and (2) how effective was our technique in minimizing hip center elevation during revision THA in clinical practice?

Methods

We retrospectively reviewed radiographic data for all patients, from one surgeon's practice, who received a jumbo cup (defined as cup size ≥ 66 mm in men, ≥ 62 mm in women) during an acetabular revision between 1998 and 2012 and who had an anatomically placed THA or no THA on the contralateral side (so as to be able to make comparisons); 98 patients were identified and included. The height of the revised hip center was measured relative to the contralateral normal hip. Cup elevation resulting from superior reaming was determined by measuring the distance from the inferior cup edge to the interteardrop line. The mean hip center elevation and cup position relative to the interteardrop line in male and female patients were compared using unpaired t-tests.

Results

Radiographic analysis showed a mean hip center elevation of 11 mm. On average, 1 mm of the measured hip center elevation was the result of cup placement superior to its planned position at the interteardop line.

Conclusions

Our results indicate that revision THA with a jumbo cup is associated with hip center elevation despite placement of the cup at the inferior acetabulum. An increase in femoral head length may be needed to compensate for hip center elevation with use of a jumbo cup.

Level of evidence

Level III, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

We present a case of a bisphosphonate-related femur fracture in an elderly woman, who failed treatment with both cephalomedullary nail and proximal femoral locking plate, leading to successful treatment with total hip arthroplasty. Hardware failure should be included in the differential of patients with previous internal fixation of bisphosphonate-related femur fracture that present with hip or groin pain. Arthroplasty can be an acceptable salvage option in an active elderly patient with a bisphosphonate-related femur fracture.