Gait Improvements After Peroneal or Tibial Nerve Transfer in Patients with Foot Drop: A Retrospective Study

Abstract

Background: Injury to the common peroneal nerve disrupts the motor control pathway to ankle dorsiflexors and evertors, as well as toe extensors, resulting in pathological gait and foot drop. Direct external compression on the fibular head is the most frequent cause of peroneal nerve impairment and has poor prognosis. Methods and Patients: Here, we report the surgical outcome of 21 patients with foot drop (9 males and 12 females) who underwent nerve transfer procedure of either the superficial peroneal nerve or the tibial nerve fascicles to the motor branch of the tibialis anterior and to the deep peroneal nerve. They had at least 6 months postoperative follow-up (mean = 17; range, 6-32 months). Results: Among 21 patients who had no ankle dorsiflexion (BMRC 0/5) preoperatively, 9 patients had successful restoration of ankle dorsiflexion (BMRC 4 to 4+/5), 7 patients had BMRC 2 to 3+/5, and 4 patients had no or poor restoration of dorsiflexion (BMRC 0 to 1+/5) but achieved good ankle eversion (BMRC 3 to 4+/5). Overall statistically significant clinical improvement of ankle dorsiflexion and eversion from preoperative BMRC grade 2.6 ± 0.5 to postoperative BMRC grade 3.6 ± 0.7 (P = .0000004) was achieved. Conclusion: Overall statistically significant clinical improvement of ankle dorsiflexion and eversion was achieved in 80% of our study patients. Most of these patients gained antigravity and were able to walk with minimal steppage gait. In the other 4 patients (20%), there was good improvement in ankle eversion but poor or no ankle dorsiflexion.

Keywords: antigravity; dorsiflexion; foot drop; nerve transfer; peroneal nerve injury.

Figure 1

(a) A 24-year-old male patient with right peroneal nerve injury and foot drop resulting from anterior cruciate ligament repair (per patient). Upper panel (A), right foot: The patient was unable to dorsiflex the ankle (BMRC 0/5) before surgery. Lower panel (B): Significant improvement in ankle dorsiflexion (BMRC 4/5), toe extension, and eversion after surgery (peroneal nerve decompression, microneurolysis, neuroplasty, and nerve transfer). (b) Upper panel (A): Steppage gait before surgery. Lower panel (B): The patient was able to walk without slapping or tripping of the foot after surgery.

Figure 1

(a) A 24-year-old male patient with right peroneal nerve injury and foot drop resulting from anterior cruciate ligament repair (per patient). Upper panel (A), right foot: The patient was unable to dorsiflex the ankle (BMRC 0/5) before surgery. Lower panel (B): Significant improvement in ankle dorsiflexion (BMRC 4/5), toe extension, and eversion after surgery (peroneal nerve decompression, microneurolysis, neuroplasty, and nerve transfer). (b) Upper panel (A): Steppage gait before surgery. Lower panel (B): The patient was able to walk without slapping or tripping of the foot after surgery.

Figure 2

(a) A 26-year-old female patient with left peroneal nerve injury and foot drop resulting from back surgery. Upper panel (A), left foot: No ankle dorsiflexion (BMRC 0/5) and toe extension (BMRC 0/5) before surgery. Lower panel (B): Full recovery of ankle dorsiflexion (BMRC 4+/5) and significant improvement in toe extension after surgery (peroneal nerve decompression, microneurolysis, neuroplasty, and nerve transfer). (b) Upper panel (A): Abnormal walking gait before surgery. Lower panel (B): Improved normal walking gait after surgery.

Figure 2

(a) A 26-year-old female patient with left peroneal nerve injury and foot drop resulting from back surgery. Upper panel (A), left foot: No ankle dorsiflexion (BMRC 0/5) and toe extension (BMRC 0/5) before surgery. Lower panel (B): Full recovery of ankle dorsiflexion (BMRC 4+/5) and significant improvement in toe extension after surgery (peroneal nerve decompression, microneurolysis, neuroplasty, and nerve transfer). (b) Upper panel (A): Abnormal walking gait before surgery. Lower panel (B): Improved normal walking gait after surgery.

Figure 3

(a) A 16-year-old female patient with right peroneal nerve injury and foot drop resulting from motor vehicle accident. Upper panel (A), right foot: Unable to dorsiflex (BMRC 0/5) the ankle before surgery. Lower panel (B): Gained significant dorsiflexion (BMRC 4/5) after surgery (peroneal nerve decompression, microneurolysis, neuroplasty, and nerve transfer). (b) Upper panel (A), right foot: pathological or neuropathic gait before surgery. Lower panel (B): No steppage gait after surgery.

Figure 3

(a) A 16-year-old female patient with right peroneal nerve injury and foot drop resulting from motor vehicle accident. Upper panel (A), right foot: Unable to dorsiflex (BMRC 0/5) the ankle before surgery. Lower panel (B): Gained significant dorsiflexion (BMRC 4/5) after surgery (peroneal nerve decompression, microneurolysis, neuroplasty, and nerve transfer). (b) Upper panel (A), right foot: pathological or neuropathic gait before surgery. Lower panel (B): No steppage gait after surgery.