Abstract
We experienced the rupture of the external rotators of the hip, which showed the same symptom that piriformis syndrome revealed.
This is a case report of a patient, forty-six years old male, who complained of pain at the left buttock and lower extremity.
On examination he had the position with the abduction and external rotation and he had an increase in pain with internal rotation and a decrease in pain with external rotation.
Also he had a positive Lasègue's sign and tenderness over the piriformis muscle.
On operation, the ruptures of the gemellus superior and the obturator internus was observed at the posterior ishium, caused by the metastatic adenocarcinoma. The ruptured muscles and the tumour was removed and the piriformis muscle was sectioned.
The primary lesion was the rectal cancer and the pull-through operation was performed four years ago.
