Authors: Charalampos Zalavras, M.D., Ph.D., Ryan Dellamaggiora, M.D., Michael Patzakis, M.D, Paul Holtom, M.D.
Title: Septic Knee Arthritis With Adjacent Osteomyelitis
Purpose: To evaluate the host-characteristics and the prevalence, location, and microbiology of adjacent osteomyelitis in patients with septic knee arthritis.
Methods: This is a retrospective review of patients with septic knee arthritis treated at our institution, which identified 152 patients with 156 involved knees. Thirty-four knees in 30 patients were associated with persistence or recurrence of symptoms after surgical drainage and adjacent osteomyelitis was diagnosed by MRI or presence of soft metaphyseal bone and positive bone cultures at the repeat debridement procedure. There were 22 male (73%) and 8 female (27%) patients with a mean age of 52 years (range, 30 to 70 years)
Results: The prevalence of adjacent osteomyelitis was 22% (34 of 156 knees). Twenty-six (87%) of 30 patients were compromised hosts. The most common factors predisposing to infection were diabetes mellitus, present in 11 patients (37%), and intravenous drug abuse, present in 10 patients (33%). Adjacent osteomyelitis involved the distal femur in 13 cases (38%), the proximal tibia in 3 cases (9%), and both locations in 18 cases (53%). Staphylococcus aureus was identified in 21 of 34 cases (63%) with 8 of these (24% of total cases) being oxacillin-resistant.
Discussion: Septic knee arthritis may be complicated by adjacent osteomyelitis of the distal femur or the proximal tibia, especially in diabetic patients or other compromised hosts. Staphylococcus aureus is the most common pathogen
Significance: Persistence or recurrence of clinical signs of infection following surgical management of septic knee arthritis should raise the suspicion of adjacent osteomyelitis, especially in compromised hosts. Repeat debridement should include the involved bone.