Intrinsic Toe Flexion Deformity Following Correction of Spastic Equinovarus Deformity in Adults

Abstract

In the treatment of spastic equinovarus foot deformities in adults with neurologic impairment, various surgical procedures are used including the split anterior tibialis tendon transfer and tendo achillis lengthening. Release of the flexor hallucis longus and flexor digitorum longus tendons in the midfoot is routinely included with these procedures to correct or prevent toe curling. In follow-up, residual toe curling has been observed in some patients despite release of the long toe flexor tendons. This study was undertaken to investigate this problem and its consequences, treatment, and treatment success. Forty-one feet in 34 consecutive patients were examined for residual toe curling an average of 2.5 years postoperatively. Thirty-two feet (78%) were noted to have significant flexion deformities of the lesser toes. The residual toe curling caused pain in 72% of the feet and was associated with callosities on the dorsum of the toes in 59%. The incidence of residual toe curling secondary to spasticity of the flexor digitorum brevis and intrinsic muscles of the foot was similar in the patients who had sustained traumatic brain injury and in those who had suffered a cerebrovascular accident. Twelve of these feet (37%) underwent surgical release of the flexor digitorum brevis and intrinsic tendons to correct the toe curling. There were no complications of surgery and no recurrences of deformity following the surgery. A second surgical procedure to release the flexor digitorum brevis and intrinsic tendons to correct the toe curling was more commonly performed in the younger more active brain-injured patients than in the older stroke patients (44% versus 20%, respectively). The second surgical procedure was also more common in the ambulatory patients compared with the nonambulators (44% versus 14%). Based on the results of this study, we recommend that release of the flexor hallucis longus, flexor digitorum longus, flexor digitorum brevis, and intrinsic tendons be performed at the base of each toe as part of the procedure to correct spastic equinovarus deformities in the adult neurologically impaired patient.