Nine-year follow-up of the cementless Ring hip.

Because of the revived interest in cementless hip prostheses, 238 Ring prostheses from the period 1968 to 1979 were reviewed; 127 hips with a median follow-up of 9 years were available for examination. Two thirds of the hips were rather painless, and 90 percent of the patients graded their result as excellent or good. Six hips had had a deep infection requiring removal of the prostheses in two hips, and 37 prostheses were removed because of loosening. By actuarial analysis the overall probability of survival and the average annual probability of removal were found to be 81 and 1.7 percent, respectively, after 12 years. The long-term survival of the Ring prosthesis seems to be comparable to the survival of some commonly used cemented prostheses.