Diagnosis of avascular necrosis of the hip in asymptomatic HIV-infected patients: Clinical correlation of physical examination with magnetic resonance imaging
Affiliations: [a] Department of Rehabilitation Medicine, National Institutes of Health, Bethesda, MD 20892, USA | [b] Department of Critical Care Medicine, National Institutes of Health, Bethesda, MD 20892, USA | [c] Warren Grant Manguson Clinical Center, National Institutes of Health, Bethesda, MD 20892, USA | [d] Department of Radiology, National Institutes of Health, Bethesda, MD 20892, USA | [e] National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
Correspondence:
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Address for correspondence: Galen O. Joe, MD, Rehabilitation Medicine Department, Warren Grant Mangusen Clinical Center, Building 10, Room 6S235 MSC-1604, Bethesda, MD 20892-1604, USA. Tel.: +1 301 496 4733; Fax: +1 301 480 0669; E-mail: gjoe@mail.cc.nih.gov
Abstract: Objective:To determine if physical examination can identify avascular necrosis of the hip (AVN) in asymptomatic HIV-infected patients. Design:Prospective, blinded population study Results:Ten of the 176 patients were positive for AVN by MRI. Four subjects had unilateral disease and six had bilateral disease. Five hips (1.4%) in four patients were indeterminate. We evaluated physical examination maneuvers both singly and in combination. Tests done singly generally provided a higher degree of specificity (67–92%) but sensitivities were lower (0–50%) with all p-values ≥0.08. Positive predictive values based on physical exam, were <17% and negative predictive values were >90% for any single test. Combining all tests gave a high sensitivity (88%) and negative predictive value (98%), but low specificity (34%) and positive predictive value (6%) with p = 0.10. Only two of 16 hips with positive MRI findings showed no abnormalities when all tests were combined Conclusions:This study establishes the limited usefulness of a detailed physical examination of the hip early in the course of AVN. Patients who test negative on physical exam are unlikely to have AVN positive by MRI. Positive findings on physical examination of the hip may help identify patients who need further evaluation by MRI based on overall clinical suspicion.
