RESUMO
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 .