The value of ultrasonography in the diagnosis of piriformis syndrome

Abstract

Objective To discuss the diagnostic value of ultrasonography in piriformis syndrome. Methods Ultrasonography was performed in thirty-eight patients with unilateral piriformis syndrome and forty healthy volunteers. The morphological structures and the internal echoes of their bilateral piriformises and sciatic nerves were observed and their thicknesses were measured. These parameters of the patients and voluteers were recorded and compared. Results The ultrasonographic images of piriformis and sciatic nerve of the healthy voluteers showed no abnormal change. The thickness difference of their bilateral piriformises and sciatic nerves had no statistical significance (P>0.05). The ultrasonography image of the morphological structure and the internal echo of the sick side piriformis and sciatic nerve of the patients with piriformis syndrome showed a change, that the sick side piriformis was significantly thicker than the healthy side piriformis [(25.74±3.12)mm vs (22.48±2.60)mm, P 0.05). Conclusions Ultrasonography can show piriformis and sciatic nerve clearly. The ultrasonographic images and the thickness difference of the bilateral piriformises is helpful to diagnose piriformis syndrome, and can provide more informations for clinic. Key words: Ultrasonography; Piriformis muscle syndrome; Sciatic nerve