Posttraumatic piriformis syndrome: diagnosis and results of operative treatment.

BACKGROUND: Posttraumatic piriformis syndrome is a rare disorder that is not clearly defined in the orthopaedic literature. We report on the specific diagnosis, operative treatment, and outcome of treatment of fifteen cases of piriformis syndrome (in fourteen patients), treated by one surgeon, in which the common etiology was blunt trauma to the buttock. We are unaware of any previously published report of this kind.
METHODS: Fourteen patients (fifteen cases of piriformis syndrome), with an average age of thirty-eight years (range, twenty-four to fifty-six years), were managed with an operative release of the piriformis tendon and sciatic neurolysis. All fourteen patients had a history of a blow to the buttock, and all had pain in the buttock, intolerance to sitting, tenderness to palpation of the greater sciatic notch, and pain with flexion, adduction, and internal rotation of the hip. Eleven patients (twelve cases) had severe radicular pain in the affected lower limb. All fourteen patients failed to improve after a prolonged period of conservative treatment with nonsteroidal medication or physical therapy, or both. On the average, the patients had been evaluated by three physicians who were not orthopaedic surgeons and by two orthopaedic surgeons before they were referred to the senior one of us. They had had an average of 4.5 diagnostic tests and an average delay of thirty-two months (range, four to seventy-one months) between the time of the injury and the operation. Preoperative electromyograms revealed extrapelvic compression of the sciatic nerve in six of the eight patients who had this study. Intraoperative findings revealed adhesions between the piriformis muscle, the sciatic nerve, and the roof of the greater sciatic notch.
RESULTS: Clinical examination at a minimum of twenty-four months (average, thirty-eight months) postoperatively revealed eleven excellent and four good results according our symptom-rating scale. All of the patients returned to work or to their usual daily activities at an average of 2.3 months postoperatively, and the time to maximum subjective improvement averaged 2.1 months. Complications included a seroma and an infected hematoma.
CONCLUSIONS: Patients who have blunt trauma to the buttock and then have signs and symptoms that are suggestive of lumbar nerve-root compression may have posttraumatic piriformis syndrome. In our group of carefully selected patients, release of the piriformis tendon and sciatic neurolysis led to encouraging results with few complications.