Walking efficiency after cemented and noncemented total hip arthroplasty.

Clinical evaluation using the Harris hip score has been supplemented with analysis of walking capacity before and after total hip arthroplasty (THA). Twenty patients were studied, ten of whom were treated with a cemented Charnley prosthesis and ten with a noncemented HP-Garches prosthesis. Tests were performed preoperatively and three, six, and 12 months postoperatively. Harris hip scores increased from a mean of 35 points preoperatively to 85 one year after surgery. Patients with a Charnley prosthesis had significantly higher scores than those with an HP-Garches prosthesis. The hip score did not differ between patients with uni- and bilateral disease. Mean maximum walking speed before surgery was 62 m/minute and increased to 80 m/minute one year after THA. The mean oxygen cost preoperatively was 0.267 ml/kg/m and decreased to 0.221 ml/kg/m one year after surgery. A weak correlation was found between differences in Harris hip scores and the corresponding oxygen cost. The onset of and the recovery from complications as well as differences between patients with uni- and bilateral diseases were reflected in changes in oxygen cost in contrast to clinical scores. The measurement of oxygen cost gave objective and valuable information about walking efficiency after THA.