Short-term results of hip revisions with a curved cementless modular stem in association with the surgical approach.

INTRODUCTION: A prospective study was designed to test the hypothesis that short-term results after hip revisions are in association with the surgical approach with lower clinical scores for the transfemoral approach. MATERIALS AND METHODS: A total of 120 hip revision operations with the modular cementless revision stem "Revitan Curved" (Zimmer GmbH, Winterthur, Switzerland), of which 42 replacements involved an endofemoral (posterolateral) approach and 78 implantations a transfemoral approach, were followed up over a period of at least 24 months. RESULTS: In the early post-operative stage, stems implanted transfemoral were associated with significantly lower Harris Hip Scores and a significantly more frequent appearance of Trendelenburg signs. The differences lessened at the end of the follow-up period. Within the group of transfemoral implantation, all six stems with a circular fixation zone measuring less than 3 cm had subsided and two of these had become loose; none of the stems with greater fixation zones exhibited these properties. In the case of the endofemoral implants, three stems exhibited sinking but there did not appear to be any relationship between this event and length of fixation zone. CONCLUSION: The surgical approach has an association with the short-time outcomes of hip revsions using cementless modular stems. Transfemoral implantation of the "Revitan curved" stem requires a fixation zone of at least 3 cm and a longer period of rehabilitation.

A modified transfemoral approach using modular cementless revision stems.

The transfemoral approach in its traditional form, using a nonmodular Wagner self-locking revision stem, has the disadvantages of a less predictable union rate of the bony flap and a high rate of stem subsidence. To investigate whether this situation can be improved by using a modified transfemoral approach and modular curved cementless revision stems, we prospectively analyzed 68 hip revisions and followed them clinically and radiographically for a minimum of 24 months (mean +/- standard deviation, 32.4 +/- 11.2 months). One year after the operation, the osteotomy showed bony consolidation in all but one case (98.5%). We noted subsidence in six cases (8.8%) and two of these stems became loose. In all of these cases, the circular fixation zone of the stem in the isthmus of the femur was less than 3 cm. The Harris hip score improved continuously from 41.4 +/- 14.5 points preoperatively to 85.9 +/- 14.6 points 24 months postoperatively. The modified transfemoral approach in combination with a curved, modular revision stem showed reproducibly good results concerning union of the bony flap and subsidence of the stem if the fixation zone was not less than 3 cm.