Aseptic loosening of cemented total arthroplasties of the hip in relation to positioning of the prosthesis. New utilization of the Tschuprow-Cramer statistical test.

A statistical study of 1200 McKee-Farrar cemented total prostheses of the hip demonstrated the importance of a horizontal position of the cup and a valgus position of the prosthetic stem, in avoiding aseptic loosening of the prosthetic parts. A new test (the Cramer test) showed that a statistical bond exists between the position of the prosthesis and the occurrence of aseptic loosening.