Abstract
We evaluated 23 hips in 21 patients at 7 months to 8 years (average 3.2 years) after Sugioka Transtrochanteric rotational osteotomy for non-traumatic avascular necrosis of the femoral head. 6 hips had secondary collapse of the femoral head after the surgery.
To clarify the risk factors for secondary collapse, we measured the intact area of the femoral head on the postoperative X-ray and preoperative MRI as well as measured the intact surface commonly used.
In conclusion, the intact surface rate of the loading area was important as previosly reported, the reasons for secondary collapse could not be explained in several cases. The incidence of secondary collapse was higher in those with intact area of the lateral region in the femoral head that is less than 90%.
