Abstract
Introduction: A consecutive series of 280 total hip replacements in 261 patients using the Morscher Press-Fit Cup with a minimum follow up of 5 years was presented 1997 in the clinical orthopaedics. Now the clinical and radiological results of the same cohort after an observation time of 15 years are reported.
Material and Methods: 136 women and 125 men with 280 hip replacements have been followed up again after 15 years. The mean age at the 15 year follow up was 76 (57–90) years in women and 73 (48–90) years in men. 63 women (66 hips) and 60 men (62 hips) died during the observation period. 17 patients with 18 hips could only interviewed by phone. 121 patients with 134 hips (48%) have been clinically und radiologically followed up. The mean observation period is 14.7 (12.8–15.8) years.
Results: The clinical outcomes are excellent and good in 117 patients (97%). Nineteen femoral stems (6.8%) and 12 cups (4.3%) had to be revised: 7 due to aseptic loosening – two after 4 and 10 years in patients with rheumatoid arthritis, 4 after a SULMESH-damage after 10, 13 (2 pat.) and 14 years and 1 after big osteolyses in the zones I-III acc. to Charnley/DeLee after 13 years -, 1 due to a late infection after 9 years, 3 because of deterioration of the inlay after 11 und 12 years (2 pat.) and one owing to recurrent dislocations followed from a fracture of the greater trochanter after 9 year follow up. The 15 year survivalrate is therefore 95.5%, for aseptic loosening 97.5%. Seven hips dislocated; two patients had a closed and 5 an open reduction.
Radiological assessment revealed a complete osseoin-tegration in all 3 zones according to DeLee and Charnley in 98%. 1 cup with a continuous radiolucent line implanted after a acetabulum fracture had to be revised after a 13 year follow-up. 10 cups migrated either in the vertical or horizontal plane 2–5 mm without any progression after 2 years postoperatively. One cup had expansile osteolyses and had therefore to be revised after 13 years. With this exception there was no evidence of osteolyses in the periacetabular pelvic bone. Brooker III and IV ectopic ossifications was seen in decentration of the head of the stem as a sign of increased polyethylene-wear. Discussion: The excellent clinical and radiological results are supported by histologic investigations of 27 autopsy-specimens which show throughout a perfect osseoin-tegration with reinforcement of the osseous anchoring in the peripheral zones of the press-fit cup. We explain the wide absence of osteolyses with the disclaiming of a metal backing (preservation of elasticity and avoiding of stress shielding) and the disclaiming of using screws.
Theses abstracts were prepared by Professor Roger Lemaire. Correspondence should be addressed to EFORT Central Office, Freihofstrasse 22, CH-8700 Küsnacht, Switzerland.
