Surgical outcomes for painless drop foot due to degenerative lumbar disorders.

STUDY

DESIGN

Twenty patients presenting with painless drop foot who had undergone lumbar spine surgery for degenerative lumbar diseases were included in this retrospective study.

OBJECTIVE

This study aims to investigate which causative factors and patient symptoms significantly affected surgical outcome.

SUMMARY OF BACKGROUND DATA: Drop foot is a neuromuscular condition that results in dorsiflexion palsy of the ankle. Patients with drop foot often complain of leg pain. Rarely, patients experience painless drop foot due to lumbar degenerative disease. For these patients, the only purpose of surgery is to improve the palsy; this makes it difficult to determine whether surgical intervention is indicated. No studies have focused on the results of surgical treatment for painless drop foot caused by degenerative lumbar diseases.

METHODS

Preoperative strength of the tibialis anterior and duration of palsy were recorded and considered with surgical outcome.

RESULTS

Sixty-five percent of patients recovered from drop foot after surgery. Drop foot was caused mainly by impairment of the L5 nerve root. Patients with a longer duration of palsy had poorer results.

CONCLUSIONS

Duration of palsy had the greatest effect on recovery. As the only goal of this surgery is improvement in the strength of the tibialis anterior, caution must be exercised when considering surgery for patients with longstanding palsy.