PERONEAL NERVE ENTRAPMENT

Sixty patients (sixty-two limbs) who had entrapment of the peroneal ne rve were managed with operative decompression, and the results were ev aluated after an average duration of follow-up of forty-two months (ra nge, twenty-five to 162 months). The entrapment was postural in five p atients, dynamic in two (one of whom had bilateral entrapment), and id iopathic in fifty-three (one of whom had bilateral entrapment). Fifty- eight patients (including the two who had bilateral entrapment) had a positive Tinel sign. Twenty-two patients (including the two who had bi lateral entrapment) had sensory symptoms only and thirty-eight had bot h sensory and motor symptoms. Electrophysiological studies were perfor med for all patients in order to confirm the diagnosis. Sensory defici ts were confirmed on the basis of a marked decrease in the amplitude o f sensory potentials, and motor deficits were confirmed on the basis o f decreased nerve-conduction velocities. The common peroneal nerve was decompressed by division of both edges of the fibular fibrous arch. T he average time from the onset of symptoms to the operation was fourte en months (range, one to 120 months), primarily because of delayed ref errals. Twelve of the twenty-two patients who had had only sensory sym ptoms preoperatively had complete recovery by the time of the latest f ollow-up. The average delay from the onset of symptoms to the operatio n was thirty months (range, six to eighty-six months) for the ten pati ents (eleven limbs) who did not have full recovery compared with nine months (range, four to thirty-six months) for the twelve patients (thi rteen limbs) who did. The postoperative recovery of motor function, as determined with use of the grading system of the Medical Research Cou ncil, was good for thirty-three (87 per cent) of the thirty-eight pati ents who had had both sensory and motor symptoms preoperatively. All s even patients who had peroneal nerve entrapment of known etiology had improvement postoperatively. We recommend operative decompression when symptoms persist or recovery remains incomplete for three to four mon ths, provided that the diagnosis has been confirmed with electrophysio logical studies.