Prevalence of equinus in diabetic versus nondiabetic patients

Background: There are no conclusive data to support the contention that diabetic patients have an increased frequency of ankle equinus compared with their nondiabetic counterparts. Additionally, a presumed contributing cause of foot ulceration is ankle joint equinus. Therefore, we sought to determine whether persons with diabetes have a higher prevalence of ankle joint equinus than do nondiabetic persons. Methods: A prospective pilot survey of 102 outpatients (43 diabetic and 59 nondiabetic) was conducted. Demographic and historical data were obtained. Each patient underwent a standard lower-extremity examination, including the use of a biplane goniometer to measure ankle joint range of motion. Results: Equinus, defined as ankle dorsiflexion measured at 08 or less, was found in 24.5% of the overall population. In the diabetes cohort, 16 of 43 patients (37.2%) were affected compared with 9 of 59 nondiabetic participants (15.3%) (P =.011). There was a threefold risk of equinus in the diabetic population (odds ratio [OR], 3.3; 95% confidence interval [CI], 1.28-8.44; P<.013). The equinus group had a history of ulceration in 52.0% compared with 20.8% of the nonequinus group (P =.003). Equinus, therefore, imparted a fourfold risk of ulceration (OR, 4.13; 95% CI, 1.58-10.77; P<.004). We also found a 2.8 times risk of equinus in patients with peripheral neuropathy (OR, 2.8; 95% CI, 1.11-7.09; P<.029). Conclusions: Equinus may be more prevalent in diabetic patients than previously reported. Although we cannot prove causality, we found a significant association between equinus and ulceration.