WHOLE AND PARTIAL SIZE-MATCHED ACETABULUM ALLOGRAFTS IN HIP REVISION WITH SEVERE ACETABULAR DEFECTS: MORE THAN 15 YEARS EXPERIENCE

Abstract

Introduction: today there is still no consense in reconstruction of severe acetabular defects in hip revision. Since 1988 we use size matched impacted acetabulum allografts. We evaluate how they behave in the mid- and longterm.

Material and method: we present our first 44 transplants with a mean follow-up of 11,2 years (range 6 to 17). The mean age of the patients was 58,6 years (range 19 to 83). According to Gross Classification 26 cases presented an acetabular defect type III while 18 presented type IV. Evaluation included Merle D’Aubigne Score and radiological assessment of allograft and cup according to Engh Criteria (JBJS, 1994).

Results: homogenization of the radiological trabecular pattern was observed in 42 from 44 cases (95,4 %). There were 3 infections and 7 cases of aseptic loosening (15,9 %), that were revised with new cup implantation. Up to now none of these 7 cases have shown further signs of loosening. According to the Kaplan-Meier’s curves the overall predictive survival rate was 76.4 % at 15 years. In cases of pelvic discontinuity (type IV) survivorship was significantly higher (85,7%, p=0,018). There was a highly marked improvement in Merle D’Aubigne Score in Gait (2,2 preoperative – 4,9 at follow-up, p=0,021) and Pain (2,5 preoperative 5,4 at follow-up, p=0,032).

Conclusions: despite published reports with high incidence of failures in the midterm with structural allografts this serie shows clearly that a size matched impacted acetabulum allograft can be successfull in severe defficiencies if proper donor selection and excellent fixation technique is undertaken.