The Paltrinieri-Trentani hip joint resurface arthroplasty.

The Paltrinieri-Trentani type of resurfacing the hip has been under clinical investigation for over 6 years. The prostheses consist of a metal cap, which is fitted to the head of the femur (no amputation of the neck and the head being required) and an acetabular cup made of high density polyethylene. Matched cups and caps are available in different sizes. The biomechanical preconditions upon which this hip resurfacing is based must be understood to successfully perform the operation. The series of patients reported here were aged between 32 and 70 years. The results after 6 years are 76% successful, and typical cases rate between 5 and 6 on the Charnley Scale; 12% rated between 3 and 4; 12% were failures owing either the fracture of the neck of the femur or to loosening of the femoral prosthesis. Further analysis of the cases demonstrated that: prostheses applied with the correct surgical technique gave satisfactory results; failures were attributable to errors of technique and indication.