Abstract:

BACKGROUND: Hyperdense line has been found at sacroiliac joints on pelvic plain film of patients with non-gluteal muscle contracture (GMC), who are finally confirmed as GMC by physical examination and pathology.
OBJECTIVE: To explore the relationship between the hyperdense line by sacroiliac joints and GMC and to investigate the effect of the hyperdense line in diagnosis and treatment for GMC.
METHODS: The pelvic plain films of 50 cases of GMC, including 45 involving gluteus maximus muscle and 5 involving gluteus medius muscle, were analyzed. Those of 100 individuals with non-GMC served as control.
RESULTS AND CONCLUSION: The hyperdense line by sacroiliac joints was found on the pelvic plain film in 42 cases of GMC group and 3 in control group. The incidence rate of hyperdense line was significantly greater in GMC group compared with control group (P < 0.01); 4 cases presented pelvic tilt in gluteal mediums main contracture group, but only 1 had the hyperdense line, while 40 cases in gluteus maximus main contracture group presented the hyperdense line (P < 0.01), indicating a correlation between hyperdense line and gluteus maximus main contracture. Results show that the hyperdense line by sacroiliac joints on pelvic plain film can be used as a sign to diagnose GMC.