Sudden peroneal nerve palsy in a varus arthritic knee

Resolution of Preoperative Peroneal Nerve Palsy After Total Knee Arthroplasty: A Case Report

CASE

We present the case of a 71-year-old man with right knee osteoarthritis (OA) and a varus deformity who developed a progressive common peroneal nerve palsy that resolved after total knee arthroplasty (TKA). After decades of knee pain, the patient gradually developed a foot drop as well as numbness and paresthesias over the foot dorsum during the course of 1 month. The patient underwent TKA and within 6 weeks postoperatively had complete resolution of the peroneal nerve symptoms.

CONCLUSION

A progressive common peroneal palsy in advanced varus knee OA may resolve after a properly aligned TKA without nerve decompression.

Sudden peroneal nerve palsy in an osteoarthritic knee: a case report

Peroneal nerve injuries have been reported in association with various causes around the knee such as traumatic varus injury, traumatic dislocation, upper tibial osteotomy, knee arthroscopy and total knee arthroplasty. Two instances of varus arthritic knee associated with a peroneal nerve palsy have been reported so far. One presented with gradual onset peroneal nerve palsy that recovered with time and the other with sudden onset peroneal nerve palsy that did not recover. We describe the case of a 63-year-old man who presented with a symptomatic varus arthritic knee and sudden onset peroneal nerve palsy with synovial cysts over the lateral aspect of the knee. We performed a total knee arthroplasty with decompression of the synovial cyst in the same patient. Three months following the surgery the patient was walking pain free with a completely recovered nerve palsy.

Surgical treatment of peroneal nerve palsy after knee dislocation

PURPOSE

Numerous surgical techniques have been described for the treatment of peroneal nerve palsy after knee dislocation with less than optimal outcomes. The purpose of this article is to present a review of the literature including modern surgical treatment options for peroneal nerve palsy after knee dislocation.

METHOD

Review of the current body of literature relevant to the topic was undertaken and summarized accordingly. Mechanism of injury, pathology and prognosis as well as current and novel treatment options are presented.

RESULTS

Neurolysis and nerve grafting results are dependent on nerve graft length, with documented recovery rates of only 44% for nerve grafts longer than 6 cm. Posterior tibial tendon transfer procedures have had reasonable success in allowing patients to return to ambulation without assistive devices; however, dorsiflexion strength on the affected side has been reported at only 30% that of the normal contralateral side, and return to activities more strenuous than walking has not been reported. Future concepts including partial nerve transfer of a motor branch of the tibial nerve to the peroneal nerve have been described, but no outcome data is currently available.

CONCLUSION

Peroneal nerve palsy after knee dislocation leads to significant functional impairment. Prior treatment strategies utilized for restoration of dorsiflexion and peroneal nerve function have yielded overall poor results. Newer surgical techniques are being developed and clinical trials are under way to evaluate their effectiveness.