Is the duration of diabetic foot ulcers an independent risk factor for developing diabetic foot osteomyelitis?

Objective

This study aimed to determine whether the prolonged duration of diabetic foot ulcers was associated with an increased incidence of diabetic foot osteomyelitis.

Study design

A retrospective cohort study

Methods

The medical records of all patients who participated in the diabetic foot clinic between January 2015 and December 2020 were reviewed. Patients with new diabetic foot ulcers were monitored for diabetic foot osteomyelitis. The collected data included the patient’s profile, comorbidities and complications, the ulcer profile (area, depth, location, duration, number of ulcers, inflammation, and history of the previous ulcer), and outcome. Univariate and multivariate Poisson regression analyses were used to assess risk variables for diabetic foot osteomyelitis.

Results

Eight hundred and fifty-five patients were enrolled; 78 developed diabetic foot ulcers (cumulative incidence 9% over 6 years, average annual incidence 1.5%) and among these diabetic foot ulcers, 24 developed diabetic foot osteomyelitis (cumulative incidence 30% over 6 years, average annual incidence of 5%, incidence rate 0.1/person-year). Statistically significant risk factors for the development of diabetic foot osteomyelitis were ulcers that were deep to the bone (adjusted risk ratio 2.50, p = 0.04) and inflamed wounds (adjusted risk ratio 6.20, p = 0.02). The duration of diabetic foot ulcers was not associated with diabetic foot osteomyelitis (adjusted risk ratio 1.00, p = 0.98).

Conclusion

The duration was not an associated risk factor for diabetic foot osteomyelitis, while bone-deep ulcers and inflamed ulcers were found to be significant risk factors for the development of diabetic foot osteomyelitis.