[Medium-term results of the cementless femoral neck prosthesis CUT].

Aim: The present work aims at evaluating the clinical and radiological midterm results of the femoral neck prosthesis CUT.

Method: 67 femoral neck prostheses of the type CUT were implanted in 63 patients between 4/1999 and 5/2003 (average age 56 years). At an average follow-up time of 5.1 years (min.: 2.9; max.: 6.9) 53 patients with 57 CUT prostheses were examined clinically with the Harris hip score and radiologically. All together we determined the state of 64 CUT prostheses (96%).

Results: The mean Harris hip score improved from 55 points preoperatively to 90.4 points at the last follow-up and is assessed as a good result. A total of 7 CUT prostheses (11%) had been revised. 3 CUT prostheses (4.7%) had been revised because of aseptic loosening, 2 (3.1%) because of persisting postoperative thigh pain, 1 (1.6%) because of vertical migration of an unsuitable CUT prostheses a few days after the operation and 1 (1.6%) because of septic loosening. The survival rate according to Kaplan-Meier was 89.1% at 5.1 years. If the femoral neck was resected too widely there was an increased rate of horizontal migration with aseptic loosening of the CUT prostheses.

Conclusion: In the midterm follow-up the CUT prosthesis shows a higher loosening rate as compared with cementless standard stems.