Osteomyelitis of the foot and toe in adults is a surgical disease: conservative management worsens lower extremity salvage

Abstract

Objective: To characterize the national epidemiology of adult osteomyelitis (OM) and, using a single institutions' experience, test the hypothesis that early surgical therapy as compared with antibiotics alone results in an improved chance of wound healing and limb salvage.

Background: Foot and digit OM is a very common problem for which management is variable and for which few guidelines exist.

Methods: The Nationwide Inpatient Sample (NIS) and a single institution review from 1993 to 2000 form the basis of this study, using ICD-9CM codes for lower extremity foot and digit OM. Demographics, risk factors, and treatments were analyzed against the outcomes of a healed wound, limb salvage, and death.

Results: The NIS included 51,875 patients (incidence = 9/10,000 patients per year) with a mean age of 60 years, and 59% were men. The median length of stay decreased from 9 to 6 days (P < 0.001), but the average admission charge of 19,000 dollars did not significantly decrease over 7 years. Of these patients, 23% underwent a digit amputation and 8.5% suffered proximal limb loss. Single-institution analysis of 237 consecutive patients with OM confirmed a similar mean age (58 years), gender (67% men), and most presented with a foot or digit ulcer (56%). Wound healing was achieved in 56% and overall limb salvage was 80%. Decreased wound healing was associated with peripheral vascular occlusive disease (odds ratio, 0.4; 95% confidence interval, 0.2-0.8, P = 0.006) and preadmission antibiotic use (odds ratio, 0.2; 95% confidence interval, 0.05-1.1, P=0.07), while surgical debridement (odds ratio, 2.2; 95% confidence interval, 1.2-4.2, P = 0.02) was associated with increased healing. Limb salvage was improved with an arterial bypass (odds ratio, 3.9; 95% confidence interval, 1.1-14, P = 0.04), while preadmission solid organ transplant (odds ratio, 0.37; 95% confidence interval, 0.14-0.96, P = 0.04), peripheral vascular occlusive disease (odds ratio, 0.25; 95% confidence interval, 0.12-0.5, P = 0.001), and preadmission antibiotic use (odds ratio, 0.34; 95% confidence interval, 0.15-0.77, P = 0.009) were associated with greater limb loss.

Conclusion: Digit OM is an expensive and morbid disease. Aggressive surgical debridement/digit amputation and selected use of arterial bypass should improve wound healing and limb salvage, respectively. In contrast, antibiotic therapy alone is associated with decreased wound healing and limb salvage.

FIGURE 1. A, Kaplan-Meier life plot analysis of CRI and limb salvage. Limb salvage was significantly lower in those patients with CRI as compared with those without CRI (P = 0.009). The bottom numbers are patients at risk at each interval. B, Kaplan-Meier life plot analysis of PVOD and limb salvage. Limb salvage was significantly lower in those patients with PVOD as compared with those without (P = 0.001). The bottom numbers are patients at risk at each interval. C, Mortality was significantly worse in patients with CRI as compared with those without (P < 0.0001).