Author(s): Holtom PD, Borges L, Zalavras CG; LAC+USC Medical Center, Los Angeles, CA
Title: Hematogenous Septic Ankle Arthritis: A 10 year retrospective study
Purpose: Infection of the ankle joint is a serious problem that can have a debilitating outcome. The purpose of this retrospective study is to present epidemiologic data aimed at better characterizing the clinical diagnosis of septic ankle guiding empiric therapy.
Methods: All admissions to Los Angeles County+USC Medical Center between 1996 and 2005 were screened to identify patients with ankle infection, shown by a synovial WBC count > 50,000, frank purulence in the joint, or positive synovial culture. 42 patients (33 male, 9 female) with a mean age of 44.8 (23 to 67 years) were identified. 12/42 patients had indwelling hardware and were excluded from further analysis.
Results: Of the 30 patients with hematogenous septic ankle arthritis, 87% reported ankle pain, 70% ankle swelling, and 50% demonstrated decreased range of motion at the ankle joint. Cultures grew Staphylococcus aureus (43%), streptococci (30%), and gram-negative rods (7%). 23% of cases were polymicrobial; no cases of Neisseria gonorrhea were identified. There were 3 cases of M. tuberculosis, and 1 case each of Coccidioides immitis and Aspergillus sp. 44% of the Staphylococcus aureus were methicillin-resistant (MRSA); no change was observed in prevalence of resistant organisms over time. Only 48% had an elevated WBC count; C-reactive protein and ESR were elevated in 100% of patients. Adjacent osteomyelitis was found in 30% of patients. Open irrigation and debridement was performed in 73% of cases; 5 patients required multiple surgical procedures and 1 amputation.
Discussion: Septic ankle arthritis presents non-specifically; a high index of suspicion is essential to ensure prompt identification and treatment. Concurrent osteomyelitis is a common finding in these patients, occurring in 30%.