PURPOSE OF THE STUDY: We evaluated the results of 309 femoral components of total hip arthroplasties performed using Charnley prosthesis and cement, by one surgeon, between January 1972 and December 1975. MATERIAL AND METHODS: Observations and measurements were based on standard pelvic X-rays. Survivorship curves were calculated to evaluate femoral component failures at twenty years of follow-up. We compared the effect of different parameters on the femoral implant loosening. RESULT: At 20 years of follow-up, 82 hips were included in the study, 227 were expelled: 109 by death, 52 by revision and 66 by loss for follow-up. Probability for death, at 20 years follow-up, was 40.7 per cent, probability for revision was 33.9 per cent, for femoral loosening was 16 per cent. The rate of aseptic femoral loosening was higher for men, with high activity and varus position of the femoral stem. Statistical analysis showed correlation between calcar resorption and femoral loosening, between polyethylene wear and calcar resorption. No directly significant correlation was established between polyethylene wear and femoral loosening. DISCUSSION AND CONCLUSION: This study confirms relations between polyethylene wear, calcar resorption and femoral loosening and underlines the influence of mechanical factors on femoral loosening. Femoral stem positioning is very important for femoral loosening. Varus position is clearly unfavourable. According to ours results, the best position is with a slight valgus.
PURPOSE OF THE STUDY: We evaluated the results of 309 femoral components of total hip arthroplasties performed using Charnley prosthesis and cement, by one surgeon, between January 1972 and December 1975. MATERIAL AND METHODS: Observations and measurements were based on standard pelvic X-rays. Survivorship curves were calculated to evaluate femoral component failures at twenty years of follow-up. We compared the effect of different parameters on the femoral implant loosening. RESULT: At 20 years of follow-up, 82 hips were included in the study, 227 were expelled: 109 by death, 52 by revision and 66 by loss for follow-up. Probability for death, at 20 years follow-up, was 40.7 per cent, probability for revision was 33.9 per cent, for femoral loosening was 16 per cent. The rate of aseptic femoral loosening was higher for men, with high activity and varus position of the femoral stem. Statistical analysis showed correlation between calcar resorption and femoral loosening, between polyethylene wear and calcar resorption. No directly significant correlation was established between polyethylene wear and femoral loosening. DISCUSSION AND CONCLUSION: This study confirms relations between polyethylene wear, calcar resorption and femoral loosening and underlines the influence of mechanical factors on femoral loosening. Femoral stem positioning is very important for femoral loosening. Varus position is clearly unfavourable. According to ours results, the best position is with a slight valgus.
Authors: Jonathan T Evans; Jonathan P Evans; Robert W Walker; Ashley W Blom; Michael R Whitehouse; Adrian Sayers Journal: Lancet Date: 2019-02-14 Impact factor: 79.321