Relationship between foot type, foot deformity, and ulcer occurrence in the high-risk diabetic foot.

We hypothesized an association between foot type, foot deformity, and foot ulceration and conducted an analysis of a well-characterized, high-risk diabetic population of 398 subjects. The average age was 62 years of age and 74% of the study population were males. Foot-type distributions were 19.5% pes cavus (high arch), 51.5% neutrally aligned (normal arch), and 29.0% pes planus (low arch). We quantified the presence of hallux valgus (23.9%), hammer/claw toes (46.7%), and hallux limitus (24.4%). A significant association was found between foot type and hallux valgus (p = 0.003); pes planus feet had the highest prevalence as compared with neutrally aligned feet (odds ratio [OR] = 2.43, p = 0.0006). Foot type was also significantly associated with fixed hammer/claw toes (p = 0.01); pes cavus feet had the highest prevalence as compared with neutrally aligned feet (OR = 3.89, p = 0.001). Foot type was also significantly associated with hallux limitus (p = 0.006) with pes planus feet having the highest prevalence as compared with neutrally aligned feet (OR = 2.19, p = 0.003). However, foot type was not significantly related to any ulcer outcome (p = 0.7). Fixed hammer/claw toes (OR = 3.91, p = 0.003) and hallux limitus (OR = 3.02, p = 0.006) were associated with increased risk of any ulcer occurrence. This study affirms that foot type and foot deformity are related and that foot deformities are associated with ulcer occurrence.