ACTIVITY AND SOCKET WEAR IN THE CHARNLEY LOW-FRICTION ARTHROPLASTY

A clinical study was undertaken to assess the influence of patient-rel ated factors on wear of the socket in Charnley low-friction arthroplas ty. One hundred nine arthroplasties in 79 patients were reviewed at an average of 10.3 years. A new method of activity assessment was design ed and used to estimate the distance walked by each patient. This meth od was validated by a pedometer that recorded the time taken by each p atient to walk 20 m. Activity level was related to the amount of movem ent at the level of the prosthetic articulation by calculating the sli ding distance of a point at the center of the surface of the head of t he femoral component. Wear was found to correlate with patient activit y, but not with the physical characteristics of the patient or the tim e since operation.