[Long-term results with the cement-free Spotorno CLS shaft]

Abstract

This retrospective study reviews 298 sequential cementless CLS Spotorno stems, which achieved their primary fixation and bony in- or ongrowth predominantly in the metaphyseal region. The minimum follow-up was 10 years and the average follow-up 11.7 years (range 10-14). The mean age at surgery was 55.2 years (range 32.2-68.9). Of the patients, 76.2% (227 stems) were followed up: 172 patients (57.7%) underwent clinical and radiological examination and 52 patients (55 stems, 18.5%) were interviewed by telephone. Of 298 stems, 13 (4.4%) had been replaced in the mean time, only 6 stems (2.0%) because of an aseptic loosening. The evaluation included both clinical (Merle d'Aubigne and Harris hip score) and radiographic parameters (plain X-rays). The mean Merle d'Aubigne score was 16.7 points, and the mean Harris hip score was 94.3 points. Radiolucent lines were detected in 33.7%; 5.8% showed enlargement within the last 3 years. Focal osteolyses were present in 30.8% of patients; 2.9% had progressed within the last 3 years. At follow-up, one patient presented with new clinical and radiological evidence of aseptic stem loosening. The current study showed an aseptic loosening of the CLS stem in 2.3%, a good osseointegration and good functional score results in more than 90%. The primary fixation and bony in- or ongrowth predominantly in the metaphyseal region seems to achieve good clinical results. Wear is the main reason for the osteolytic changes. Frequent clinical and radiological follow-up is important to detect bone reactions and loosening of the stem.