Residual diabetic foot osteomyelitis after surgery leads to poor clinical outcomes: A systematic review and meta-analysis.

The aim of this meta-analysis is to compare the clinical outcomes in patients with and without residual osteomyelitis (ROM) after surgical bone resection for diabetic foot osteomyelitis (DFO). We completed a systematic literature search using PubMed, Scopus, and Embase using keywords DFO, Residual OM (ROM), and positive bone margins. The study outcomes included wound healing, antibiotic duration, amputation, and re-infection. Five hundred and thirty patients were included in the analysis; 319 had no residual osteomyelitis (NROM), and 211 had ROM. There was not a significant difference in the proportion of wounds that healed 0.6 (p = 0.1, 95% confidence intervals [95% CI] 0.3-1.3). The risk of infection was 2.0 times higher (OR = 2.0, p = 0.02, 95% CI 1.1-3.4), and the risk of amputation was 4.3 times higher (OR = 4.3, p = 0.0001, 95% CI 2.4-7.6) in patients with ROM. Patients with ROM received antibiotics significantly longer. The mean difference was 16.3 days (p = 0.02, 95% CI 11.1-21.1).

Does complete resection of infected bone improve clinical outcomes in patients with diabetic foot osteomyelitis?

The objective of the study was to compare outcomes in patients with complete surgical resection versus partial resection of diabetic foot osteomyelitis (OM). A post hoc analysis of 171 patients with OM was performed using data from two randomized clinical trials. OM was confirmed with bone culture or histopathology. Surgical culture specimens were obtained from resected bone and sent for histopathology and microbiology. Residual osteomyelitis (RO) was defined as a positive resected margin on culture or histopathology. No residual osteomyelitis (NRO) was defined as no growth from bone culture and no histopathological inflammation in the biopsy of the resection margin. Data from the 12-month follow-up were used to determine clinical outcomes. During the index hospitalization, NRO patients had significantly shorter duration of antibiotic therapy (NRO 21.0, 13.0-38.0 vs. RO 37.0, 20.8-50.0, p <0.01) and more amputations than patients with RO (NRO 89.9% vs. RO 60.9%, p <0.01). During the 12-month follow-up, patients with NRO also had significantly shorter duration of antibiotic therapy (NRO 42, 21.0-66.5 vs. RO 50.5, 35.0-75.0, p = 0.02). During the 12-month follow-up, there was no difference in ulceration at the same site (NRO 3.7%, RO 4.3% p = 0.85), hospitalization (NRO 32.6%, RO 34.8%, p = 0.76), total re-infections (NRO 25.3%, RO 29.3%, p = 0.56), re-infection with osteomyelitis (NRO 13.3% vs. 13.5%, p = 0.36), amputation (NRO 8.8%, RO 5.4%, p = 0.86) and time to wound healing in days (NRO 94, 41.0-365 vs. RO 106, 42.8-365, p = 0.77). Successful treatment of osteomyelitis was achieved by 86.7% and 86.5% of patients. During the index hospitalization, patients with no residual osteomyelitis had more amputations and were treated with antibiotics for a shorter duration. During the 12-month follow-up, patients with no residual osteomyelitis had shorter durations of antibiotics. There were no differences in re-infection, amputation, re-ulceration or hospitalization. Level of evidence: 1.

Methicillin-resistant Staphylococcus aureus in diabetic and non-diabetic foot infections.

To identify the incidence of methicillin-resistant Staphylococcus aureus (MRSA) infection, reinfection and clinical outcomes. Four hundred forty-six patients that were admitted to the hospital with moderate or severe foot infections were retrospectively reviewed. Tissue and bone cultures were obtained from the index hospital admission. Conversion was defined as methicillin susceptible Staphylococcus aureus in the first culture and subsequently MRSA when there was a reinfection. The incidence of MRSA was 7.8% (n = 35), with no significant difference between soft tissue infections (7.7%) and osteomyelitis (8.0%). MRSA incidence was 9.4 times higher in non-diabetics (23.8% vs. 3.2%, p = <0.01). The incidence of reinfection was 40.8% (n = 182). Conversion to MRSA was seen in 2.2% (n = 4) total, occurring in 5.4%. Non-diabetics were 20.1 times more likely to have MRSA reinfection than people with diabetes (28.6% vs. 1.9%, p < 0.001). MRSA patients had a higher proportion of healed wounds (82.4% vs. 69.3%, p = 0.02). There were no differences in other clinical outcomes in MRSA vs. other infections in reinfection (28.6% vs. 24.3%, p = 0.11), amputation (48.6% vs. 52.0%, p = 0.69) or hospitalization (28.6% vs. 42.6, p = 0.11). The incidence of MRSA for the first infection (7.8%), reinfection (6.0%) and conversion to MRSA (2.2%) was low. MRSA was 9.4 times more common in people without diabetes.