What clinical features would lead to suspicion of of Osteonecrosis?
The signs and symptoms stemming from ON are nonspecific. Pain is what leads affected individuals to seek medical evaluation. For the hip, which is the most commonly involved joint, pain is unilateral at onset and localizes to the groin, buttock, medial thigh, and medial aspect of the knee. Pain occurs with weight bearing but can be present at rest (66%) and at night (33%) because of elevated intraosseous pressure. Occasionally, knee pain is the major complaint in an individual with late-stage ON of the hip. Typically, morning stiffness is absent or of short duration (<1 hour), allowing differentiation from inflammatory monoarticular arthritides. Range of motion is not affected, except as limited by discomfort, until late degenerative changes develop. Although these findings are common to other potential etiologies, their occurrence in the setting of a patient with a predisposing risk (e.g., recent trauma, high-dose steroid use) should suggest underlying ON.
