Fellow Mayo Clinic Rochester Rochester, Minnesota, United States
Disclosure(s):
Ken Porche, MD: No financial relationships to disclose
Introduction:
Background: This study investigates characteristics and outcomes in double crush syndrome related to ganglion cysts in the lower extremities, specifically L5 radiculopathy and peroneal neuropathy.
Methods:
Methods: We conducted a retrospective analysis of 14 patients treated for double crush syndrome involving L5 radiculopathy and peroneal nerve ganglion cysts at two quaternary institutions between 2001 and 2021. Patients were classified by cyst type, synchronicity of symptoms, and timing of diagnoses. Preoperative clinical data, imaging, and EMG findings were analyzed. Outcomes included motor, sensory, and pain improvements following peroneal nerve decompression surgery with or without lumbar surgery.
Results:
Results: Fourteen patients met inclusion criteria with an average age of 55±10 years and follow-up of 236±155 days; 9/14 (64%) had intraneural cysts, 8/14 (57%) had synchronous presentations, and 5/14 (36%) underwent lumber surgery prior to peroneal nerve treatment. Preoperative EMG confirmed L5 radiculopathy vs active peroneal neuropathy in all cases, with reduced conduction velocities and amplitudes in the affected peroneal nerve. Average preoperative strength of dorsiflexion/toe extension/eversion was 1.9±1.7/1.9±1.8/2.4±1.9 (MRC). All patients experienced dysesthesia and 93% reported pain. Postoperatively, MRC scores improved +1.3/+1.1/+1.1 points in dorsiflexion/toe extension/eversion. Pain improved in 83.3% of patients, and 58% experienced numbness relief. Multivariable models revealed that preoperative tibial motor conduction speed (B=0.41 MDC per ms-1, p<.001) and peroneal sensory conduction speed (B=0.06 MDC per ms-1, p=0.048) were independent predictors of postoperative functional improvements. Two patients (14%) required subsequent lumbar surgery. Timing of pre-peroneal lumbar surgery, cyst type, synchronicity, and radiographic tibial involvement were not found to be associated with outcomes.
Conclusion :
Conclusion: In patients with double crush syndrome involving L5 radiculopathy and peroneal nerve ganglion cysts, most patients experienced reduced pain and enhanced motor strength following peroneal nerve decompression, regardless of prior lumbar surgery. Preoperative tibial motor and peroneal sensory conduction speeds were significant predictors of postoperative functional improvements.
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