5 TO 10-YEAR RESULTS WITH MULLER STRAIGHT STEM ENDOPROSTHESES

103 patients with 106 Muller straight stem prostheses could be evaluat ed clinically and radiologically after an average follow-up period of 6.8 years (range 5 to 10 ys.) Although until now no revision for asept ic loosening has become necessary 3 p.c. of the stems and 11 p.c. of t he acetabular components showed radiological loosening. The clinical r esults were rated as satisfactory. After surgery 67 p.c. of the patien ts were completely painfree, 28 p.c. still had slight pain, 4 p.c. mod erate and 1 p.c. severe pain. The investigation concentrated particula rly on radiographic changes of the interface of the femur. Whereas rad iolucency typically was non-progressive and located in the proximal pa rt of the femur we found an increasing atrophy of the cortical bone on the calcar. Moreover, we found a continuous and increasing subsidence of the stem during the whole period of observation. At the time of fo llow up 56 p.c. of the straight stems had subsided about 2 mm and more . Calcar atrophy and radiolucency were significantly less present in f emurs with a tapered medullary canal than in those with a cylindrical shape.