Abstract
Background: Piriformis muscle syndrome (PMS) is relatively less known and underestimated because
it is confused with other clinical pathological conditions. Delays in its diagnosis
may lead to chronic somatic dysfunction and muscle weakness. Objective: Here, we aimed to evaluate the diagnostic performance of the ultrasound elastography
(UE) as an easy, less-invasive, and cost-effective method for early diagnosis of PMS.
Materials and Methods: Twenty-eight cases clinically diagnosed as PMS at the outpatient clinic were evaluated
by UE. The elastographic strain ratio was calculated by dividing the strain value
of the subcutaneous fat tissue by the mean stress value of the muscle beneath. The
diagnostic performances of the strain rate measures were compared using the receiver
operating characteristic curve analysis. Results: Twenty-one (N = 21) cases were female, and seven (N = 7) of the cases were male. The mean age was 45 years (ranged 24–62 years). The
strain rates of piriformis muscle (PM) and gluteus maximus (GM) muscles were significantly
higher on the PMS-diagnosed side (P < 0.001). The cutoff value of UE strain ratio for the PM and GM were 0.878 [95% confidence
interval (CI) 0.774–0.981] and 0.768 (95% CI 0.622–0.913), respectively, and the sensitivity
and specificity values were, respectively, 80.95% and 85.71% for the PM, and they
were, respectively, 85.71% and 66.67% for the GM. Conclusion: We showed that the muscle elasticity and tissue hardening increased on the problematic
side both on PM and GM. UE may provide early diagnosis of PMS, thereby increasing
the possibility of treatment with less invasive methods.
Keywords
Elastography - piriformis muscle syndrome - ultrasound
