[Acetabulum reinforcement ring with allograft bone for reconstructing acetabular defects in hip revision].

OBJECTIVE

To evaluate the effectiveness of acetabulum reinforcement ring (Cage) with allograft bone for reconstructing acetabular defects in hip revision.

METHODS

Between February 2006 and August 2010, 14 patients (14 hips) with serious acetabular bone defects after total hip arthroplasty underwent acetabular reconstruction by using Cage with allograft bone. There were 6 males and 8 females with a mean age of 59.2 years (range, 45-76 years). The mean time between first replacement and revision was 7.2 years (range, 5-12 years). The revision causes included infection in 8 cases, osteolysis and aseptic loosening in 6 cases. The hip function Harris score was 37.7 +/- 5.3. According to America Association of Orthopedic Surgeon (AAOS) standard, the acetabular defect was classified as type III in 8 cases and as type IV in 6 cases.

RESULTS

All incisions healed by first intention, and no complication occurred. The patients were followed up 14-62 months (mean, 44 months). The pain was relieved or disappeared. At last follow-up, the Harris score was 89.7 +/- 3.2, showing significant difference when compared with preoperative score (t = -44.40, P = 0.04). No loosening of the acetabular component or osteolysis was found in 14 hips. No absorption or collapse of the allograft was observed in all patients.

CONCLUSION

Cage with allograft bone is a useful method of reconstructing acetabular bone defects in hip revision. Further follow-up is needed to assess the long-term effectiveness.