The Thrust Plate Hip Prosthesis: A Follow-Up of 15-20 Years With 102 Implants.

BACKGROUND: Between November 1992 and January 1999, a cohort of 102 thrust plate hip prostheses was implanted. METHODS: We now clinically and radiologically evaluate the remaining 73 prostheses with a mean follow-up of 17.2 years. RESULTS: The Harris Hip Score increased from 51.4 points preoperatively to 94.3 points at the time of this follow-up. No further changes in the radiologic findings occurred since the first follow-up, published in 2005, conducted 2-8 years after implantation. Within 15 to 20 years after primary implantation of the 102 prostheses, 6 aseptic loosenings occurred, which correspond to a cumulated survival rate of 94.7% at 17 and 91.8% at 18 years. CONCLUSION: Although the thrust plate hip prostheses is no longer marketed, the biomechanical behaviour of this unique, clinically successful prosthesis deserves attention.

Radiological findings and clinical results of 102 thrust-plate femoral hip prostheses: a follow-up of 2 to 8 years.

We report the radiological and clinical outcome of 102 consecutive femoral hip arthroplasty we prospectively followed up in 84 patients using the third generation of the thrust-plate prosthesis with a mean period of follow-up of 58 (range, 26-100) months. Four implants were revised: 2 because of an infection and 2 because of aseptic loosening. The thrust-plate prosthesis, which allows preservation of part of the femoral neck, was used in younger patients, 80% were younger than 60 years. In 95 implants, contact was maintained between thrust plate and underlying bone, and in only 3 instances, without any clinical manifestation, did the bone retract from the thrust plate to the extent that a gap appeared. The extent of radiologically evident bone contact with the flat surface of the thrust plate, as a consequence of the bone remodeling behavior, is described and retrospectively classified. The average Harris hip score increased from 51 points preoperatively to 96 points postoperatively at the last follow-up. Survivorship analysis according to Kaplan-Meier showed a survival rate of 98% after 6 years, with no further losses up to the end of the 8-year follow-up period.