Factors Influencing the Results in 2,012 Total Hip Arthroplasties

Abstract

We have previously described1–3 the early successful results obtained in 2,012 Charnley hip replacement operations. These results—in operations performed between March 1, 1969, and June 30, 1971, at the Mayo Clinic—led to an increasing number of patients being selected for the total hip operation. Because an accumulation of data was anticipated, computerized methods of preoperative and postoperative patient evaluation were established before the prospective study was begun. Use of these methods and of a computer has made possible rapid and accurate collation of data and also determination of the many factors influencing the result of total hip arthoplasty; details of computer programming and data analysis arc described later. The purpose of this paper is to review several interesting relationships that have come to our attention in analyzing more than 300,000 items of information recorded about 2,012 hips. Of this total of 2,012 hips, 2 groups of hips were studied: (1) the first 333 hips (unilateral and bilateral) operated on during the first year (March 1, 1969, to February 28, 1970); and (2) the 1,126 unilaterally diseased hips operated on during the next 15 months (March 1, 1970, to June 28, 1971). In analyzing the immediate postoperative results, we studied the findings of unilateral hips only; in this way we were able to eliminate any possible confounding of the results from inclusion of data pertaining to hips of patients having bilateral operations.