Osteomyelitis: Procalcitonin to Diagnose and Monitor Osteomyelitis

The investigator plans a cohort study of 80 subjects admitted to hospital with a diabetic foot infection in order to compare serial bone biopsies (the current "gold standard") and procalcitonin to diagnose and monitor the effectiveness of therapy for osteomyelitis. The investigator will collect specimens as part of an existing trial to evaluate negative pressure wound therapy in diabetic infected wounds. A high proportion of these patients have osteomyelitis and will receive standard therapy including repeat bone biopsy and parenteral antibiotics. The investigator expects repeated measurement of procalcitonin will be highly correlated with repeated bone biopsy after antibiotic treatment has been completed to determine if therapy has been successful or if additional antibiotic therapy is needed.