2004 Abstract : CS 6

Authors: Charalampos G. Zalavras, MD, PhD, Neeraj Gupta, MD, Michael J. Patzakis, MD, Paul Holtom, MD.

Title: Osteomyelitis in Patients Infected With the Human Immunodeficiency Virus

Addresses: Department of Orthopaedic Surgery, University of Southern California, LAC+USC Medical Center, 1200 N State St GNH 3900, Los Angeles, CA 90033

Purpose: Although autoimmune musculoskeletal manifestations associated with human immunodeficiency virus (HIV) infection are common, osteomyelitis rarely develops despite the immunosuppressive effect of the HIV infection and the literature on this topic is very limited. The purpose of this study was to describe the clinical and microbiological features of osteomyelitis in HIV-infected patients. Our hypothesis was that atypical pathogens may play a considerable role in the aforementioned setting.

Methods: Medical records of HIV-infected patients who were admitted to the musculoskeletal infection ward of our institution with the diagnosis of osteomyelitis were retrospectively reviewed. Patient demographics, comorbidities, clinical presentation, laboratory and microbiological data were recorded.

Results: Twenty HIV-positive patients with osteomyelitis were identified. There were 17 male and 3 female patients with a mean age of 40 years, ranging from 22 to 60 years. Seventeen patients (85%) reported smoking and substance abuse, with 11/20 (55%) using intravenous drugs. Medical co-morbidities were present in 14/20 patients (70%), including tuberculosis in 5 patients and hepatitis B and/or C in 3 patients (15%). A history of previous infectious process elsewhere was present in 4 patients (20%). Only 5 patients (25%) were receiving anti-HIV medications at the time of diagnosis. The mean CD4 count was 269/mm3, ranging from 20 to 539/mm3. Overall, the infectious process involved the lower extremity in 13 patients and the upper extremity in 7 patients. The most common locations were the tibia and fibula (5 patients), the foot and ankle (5 patients), and the hand (4 patients). The osteomyelitis was post-surgical in 10 cases, post-traumatic in 6, and was considered hematogenous in 4. Fifteen patients (75%) had erythema and/or a draining sinus. Fever was present in 7 (35%).
The osteomyelitis was monomicrobial in 10 patients (50%), polymicrobial in 7 (35%), whereas in 3 patients no organism was identified at culture. Overall, the most common pathogen was Staphylococcus aureus, present in 10 cases (50%), 3 of which were oxacillin-resistant. Coagulase-negative Staphylococcus was present in 5 cases (25%), beta Streptococcus in 4 (20%), Enterobacter species in 3 (15%), and vancomycin-resistant enterococci in 2 cases (10%).

Discussion: Osteomyelitis in HIV-infected patients predominantly affects the lower extremity and usually results from previous trauma or surgery. Despite their immunocompromised status, HIV-infected patients did not develop osseous infections with opportunistic pathogens. Staphylococcus aureus was the most common pathogen, however, a considerable proportion of infections were polymicrobial.

Significance: Osteomyelitis in HIV-infected patients demonstrates usual clinical and microbiological features, without presence of atypical pathogens.