EXTREME VARIATIONS IN RACIAL RATES OF TOTAL HIP-ARTHROPLASTY FOR PRIMARY COXARTHROSIS - A POPULATION-BASED STUDY IN SAN-FRANCISCO

Objectives-To compare the incidence of all total hip arthroplasty, and total hip arthroplasty for primary coxarthrosis, among the Asian, bla ck, Hispanic, and white populations living in one locale. Methods-We i dentified all San Francisco residents who underwent total hip replacem ents (THR) in the 17 hospitals for or near San Francisco during a five year period. Preoperative pelvic radiographs were read without prior knowledge of the gender or race of the subject, to diagnose the specif ic hip diseases. Age standardised THR incidence by race and gender was determined, as was the comparative THR incidence for specific diagnos is (primary and secondary osteoarthritis). Results-The greatest annual rate of total hip replacement occurred in white women (97 per 100000 population), followed by white men, black women, black men, Hispanic w omen, and Hispanic men. The smallest numbers were found in Asians, who se THR rate was 10% that of whites. A primary coxarthrosis greatest am ong white followed by black Hispanics (53%), and Asians (28%). Age sta ndardised THR rates for primary coxarthrosis per 100000 population wer e Likewise greatest among whites (43.0) and least among Asians (1.3 fo r Chinese). Mean age of patients undergoing THR for primary coxarthros is was 70 years for white subjects and almost a decade younger in all other groups. Conclusions-THR rates are much lower for Asians, Hispani cs, and black subjects than for the white population living in San Fra ncisco. The low rates of total hip arthrosplasty in the non-white grou ps was related to the much lower incidence of Honolulu THR for primary coxarthrosis among non-whites than among whites. The racial distribut ion of primary coxarthrosis among patients who underwent THR is consis tent with distribution patterns reported internationally.