the tenyear pattern of hip diseases in singapore purpose to review patients with hip diseases undergoing total hip arthroplasty tha during 2 different periodsmethods 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 postoperative radiographs of the pelvis and hip were reviewed the femoral headtilt ratio fhr was measuredresults the number of patients undergoing tha increased 3fold 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 107 there was no significant difference between male and female subjectsconclusion the pattern of hip diseases in singapore remained similar over the 10year interval but the number of patients undergoing tha had increased 3fold