Prevalence of osteonecrosis of the femoral head: a nationwide epidemiologic analysis in Korea.

This study was performed to estimate the prevalence of osteonecrosis of the femoral head in Korea. Using medical claims data from the Korean National Health Insurance Corporation, all individuals treated under a diagnosis of osteonecrosis of the femoral head were identified for each year from 2002 to 2006. Among them, the number of true cases was estimated using a randomly collected validation sample of 382 patients for which the actual diagnosis was investigated by authors. The estimated yearly prevalence per 100 000 population ranged from 20.53 (20.13 <or= 95% confidence interval <or= 20.94) in 2002 to 37.96 (37.42 <or= 95% confidence interval <or= 38.51) in 2006. The average estimated number of annual prevalent cases was 14 103, indicating 28.91 per 100 000 average prevalence over a 5-year period. Males predominated. We found that 32.4% had history of alcohol abuse, and 14.6% was related to steroid. Bilateral involvement was noticed in 37%. Besides arthroplasty, decompression was the most frequently performed joint-preserving procedure. We believe that the results serve as important baseline for understanding the disease.