Early Clinical Results in the Use of a Tantalum Trabecular Metal System For Osteonecrosis of the Femoral Head

ABSTRACT

PURPOSE: To evaluate the effectiveness of core decompression using a tantalum trabecular metal system for treatment of early stage osteonecrosis of the femoral head, with a minimum follow-up of 1 year and a maximum follow-up of 5 years. MATERIALS AND METHODS: Between January 2003 and August 2007, a retrospective analysis was conducted on 46 femoral heads in 36 patients (9 males and 27 females) underwent core decompression using a tantalum trabecular metal system. The mean duration of follow-up was 26 months (minimum, 1 year; maximum, 5 years). The ARCO classification system was used. The mean age of the patients was 42.9 years. The conversion to total hip arthroplasty due to aggravating hip pain was defined as a clinical failure. RESULTS: At an average of 12 months, 18 patients (21 hips) were converted to THR. No conversion to THR in occurred in stages IA or IIA. In Stage IB, one-half of the medial lesion and all of the lateral lesions were converted to THR. One of 11 medial lesions and all of the lateral lesions in stage IC were converted to THR; 2 of 3 medial lesions and all of the lateral lesions in stage IIB were converted to THR. In stage IIC, 6 of 8 lateral lesions were converted to THR, but the central lesions were not converted. All of the lateral lesions in stage IIIC were converted to THR. CONCLUSION: The higher stage of ARCO classification and the more lateral position of the lesion, the greater the failure rate of the tantalum trabecular metal system. Conversion to THR from a failed tantalum trabecular system developed within 12 months postoperatively. The tantalum trabecular metal system is a useful treatment for osteonecrosis of the femoral head with a lower stage of ARCO classification and a medial location of the lesion.