Objective: Subchondral insufficiency fracture of the femoral head (SIF) is a recently recognized cause of acute onset arthritis mostly in elderly women, which previously had been commonly considered either as osteonecrosis or osteoarthritis. The purpose of this study is to report the histopathologic incidence of SIF using surgically removed femoral heads.
Methods: We have reviewed 7,718 consecutive femoral heads from 7,286 patients removed over a four-year period (2001-2004). There were 4,211 females and 3,507 males. The age range was from 13 to 96, out of average age of 60. There were 7,349 hips with a preoperative clinical diagnosis of osteoarthritis and 369 with a preoperative clinical diagnosis of osteonecrosis.
Results: SIF was diagnosed histologically as the primary process in 501 out of 7,718 resected femoral heads (6.5%). The age range in these patients was from 20 to 93, with an average age of 68, in which 79 % (394 hips) were over 60s. They were 305 hips in females and 196 in males. The affected side was right in 253 hips and left in 248. The prevalence of SIF in cases with a preoperative diagnosis of osteoarthritis was 6.3 % (460 out of 7,349), and with osteonecrosis was 11.1% (41 out of 369). In all cases, callus and granulation tissue were histologically observed along the fracture line.
Conclusion: In this large series of total hip replacements SIF as the cause of disease was diagnosed histologically in 6.5 % of the surgically removed femoral heads.
- subchondral insufficiency fracture