The ten-year pattern of hip diseases in Singapore.

PURPOSE To review patients with hip diseases undergoing total hip arthroplasty (THA) during 2 different periods. METHODS During the periods 1994 to 1996 and 2004 to 2006, 12 men and 28 women (mean age, 57 years) and 55 men and 78 women (mean age, 62 years) underwent THA for hip diseases, respectively. The aetiologies of the hip diseases were classified. Preand post-operative radiographs of the pelvis and hip were reviewed. The femoral head-tilt ratio (FHR) was measured. RESULTS The number of patients undergoing THA increased 3-fold over 10 years; the proportion of different aetiologies was similar. Respectively, the most common aetiologies were acetabular dysplasia (33% vs. 40%) and avascular necrosis (33% vs. 42%). Only less than 5% of the patients had advanced osteoarthritis with no demonstrable cause, most of whom being Caucasians. The overall mean FHR was 1.07. There was no significant difference between male and female subjects. CONCLUSION The pattern of hip diseases in Singapore remained similar over the 10-year interval, but the number of patients undergoing THA had increased 3-fold.