Association of Magnetic Resonance Imaging-Guided Management With Reamputation Rates in Diabetic Foot Osteomyelitis

Background: Diabetic foot infections constitute 20% of hospital admissions and are the underlying cause of 80% of amputations annually. Staging magnetic resonance imaging (MRI) may decrease reamputation rates in diabetic foot osteomyelitis. Methods: A retrospective chart review was conducted to analyze the risk of reamputation in patients with diabetic foot osteomyelitis hospitalized between 2005 and 2022. MRI-guided therapy and proximal surgical margin pathologic evidence of osteomyelitis were compared. The primary outcome was the rate of reamputation up to 365 days. Results: Enrollment consisted of 386 veterans with a diabetic foot infection complicated by osteomyelitis that required initial amputation, of which 110 patients required reamputation. MRI-guided therapy occurred in 89 of these patients. Preoperative MRI and subsequent MRI-guided therapy were associated with a significant decrease in the chance of reamputation for up to a year after the initial amputation as compared with non-MRI-guided therapy (14/89 [15.7%] vs 96/297 [32.3%], respectively; P =. 0024, χ² test). A Cox proportional hazard model demonstrated that MRI-guided therapy had a significant association with decreasing the relative risk of reamputation (hazard ratio, 0.47; 95% CI,. 26-.83; P =. 0098). Initial proximal margin pathologic findings consistent with osteomyelitis were not associated with the risk of reamputation (hazard ratio, 1.25; 95% CI,. 81-1.93; P =. 31). Conclusions: These findings support that incorporating preamputation MRI and MRI-guided therapy into the diagnostic and treatment approach for diabetic foot osteomyelitis may reduce the risk for subsequent amputations over 1 year.