A prospective cohort study of the clinical presentation of non-traumatic osteonecrosis of the femoral head: spine and knee symptoms as clinical presentation of hip osteonecrosis.

PURPOSE: To study the clinical presentation of femoral head osteonecrosis (ONFH). Publications dedicated to this aspect of ONFH are rare. Our aim was to systematically collect and describe the clinical data.

METHODS: A prospective survey was conducted in a cohort of ONFH recruited from a dedicated clinic for osteonecrosis. The history of symptoms, medical management, and physical findings were obtained from 88 patients suffering from 125 ONFH. Subgroups were formed: bilateral versus unilateral ONFH, radiological stages 1-2 (pre-fractured) versus fractured stage 3 versus stage 4.

RESULTS: ONFH was bilateral in 63 %, especially in corticosteroid users and in sickle-cell cases. These patients were younger but had similar BMIs compared to the unilateral cases. The pain was mechanical in 79 % of hips and inflammatory in 21 %. Acute pain at the onset was present in 55 % of hips. The localization of this pain was variable, including in the groin, the buttocks, or diffused in the lower limbs. A limp was present in 50 % of the patients, only when one hip was painful. The physical examination of the hip was normal in 31 %, especially in stages 1-2 (55 %). The diagnosis delay was 12 months, with inadequate medical management in 51 % of patients.

CONCLUSIONS: In ONFH cases, no typical clinical pattern was found. The clinical presentation was very variable, sometimes having spine or knee symptoms with a normal physical examination of the hip. ONFH should be systematically suspected in cases of onset of pain in the pelvis, buttocks, groin, and lower limbs.