Iatrogenic nerve injury and foot drop: Surgical results in 28 patients

Background: Most peroneal nerve injuries resulting in foot drop are secondary to trauma or iatrogenic. Foot drop can occur due to potential complications from the hip, lumbosacral spine, and knee surgeries, which are critical to diagnose and manage. Methods: We reviewed our foot drop patients’ data to determine the incidence and iatrogenic causes of the injury and managed surgically by neurolysis of the peroneal nerve and transfer of functional fascicles of either the superficial peroneal or the tibial nerve to the deep peroneal nerve. Results: We found 28 iatrogenic foot drop patients who have had surgery and postoperative follow-up evaluations with us. Before the onset of foot drop, all except one (27 of 28) patient have had surgeries in other clinics before presenting to our institution. Foot drop in one patient was due to infection and hip wound after he was intubated and stayed in ICU for 4 weeks. Thirteen of the 28 patients have had lumbosacral (L3-4, L4-L5, and L5-S1) fusion or laminectomy, eight have had hip surgery, and five have had knee surgery. One patient had a fasciotomy due to compartment syndrome and another patient had two previous surgeries for posterior tibial entrapment and tarsal tunnel syndrome at other institutions. NCS and EMG reports showed that these patients had injuries to the peroneal or tibial nerve after their prior surgeries. One patient had a femoral nerve injury. Preoperatively, 10 patients had severe foot drop with muscle weakness and a functional grade of 0/5; 16 patients had grades ranging from 1 to 2/5; and two patients had 3/5. Overall, 23 of the 28 patients (83%) had improvement in their ankle dorsiflexion with anti-gravity and regained a healthier gait after the decompression, neurolysis, and nerve transfer at our clinic. Conclusion: Twenty-three of the 28 (83%) iatrogenic foot drop patients in this report regained a healthier gait with improved ankle dorsiflexion and anti-gravity after the neurolysis, and nerve transfer of the peroneal or tibial nerve and transfer of functional fascicles of either the superficial peroneal or the tibial nerve to the deep peroneal nerve at our clinic.