A STATISTICAL-ANALYSIS OF HIP SCORES

Thirteen methods of hip scoring were applied in the postoperative asse ssment of 47 hip arthroplasties. Their results were found to be incons istent, often giving contrary measures of success in the same patient. Ten variables were measured during the postoperative review of 256 hi p arthroplasties and the data were submitted to multivariate factor an alysis. This revealed that the ten variables could be reduced to three factors: pain, which correlated poorly with any other variable (Spear man correlation, r < 0.02); functional activity (distance walked, use of walking aids, stair climbing, use of public transport, limp, sittin g and tying shoelaces); and deformity and range of movement. The range of hip flexion correlated closely with the sum of the arcs of movemen t and with Gade's index (Spearman correlation, r > 0.9). We suggest th at, for outcome assessment, only three variables need to be recorded: pain, walking distance and range of hip flexion. The combination of th ese three measures into a single hip score is misleading.