Objective
To show the prevalence of the dorsomedial cutaneous nerve (DMCN) injury in the hallux valgus and to evaluate whether the sensory nerve damage contributes to pain and sensory impairment in the great toe.

Method
Sixty feet of healthy adults (normal group) and 26 feet of patients with hallux valgus (hallux valgus group) were evaluated with sensory nerve conduction study of DMCN. The prevalence of the nerve injury was compared between the two groups. Sensory nerve action potentials of DMCN in hallux valgus feet were analyzed and compared according to the patient's symptom and the severity of the radiographic measurements of the feet.

Results
The prevalence of DMCN injury was 42.3% of the hallux valgus group. The peak latency of the DMCN sensory action potential of the symptomatic feet showed statistically significant delay compared to the asymptomatic group (p＜0.05). Delay of the peak latency and decrement of the amplitude of the DMCN were statistically significant among the three groups as the valgus deformity worsened (p＜0.05).

Conclusion
DMCN injury should be considered in addition to soft tissue injury or arthritis in the differential diagnosis of the pain, burning sensation or numbness associated with hallux valgus.