Diagnostic accuracy of clinical tests for sciatic nerve entrapment in the gluteal region

• Published in: Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA Vol. 22; no. 4; pp. 882 - 888
• Main Authors: Martin, Hal D., Kivlan, Benjamin R., Palmer, Ian J., Martin, RobRoy L.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.04.2014; John Wiley & Sons, Inc
• Subjects: Accuracy; Adolescent; Adult; Buttocks; Child; Endoscopy; Female; Hip; Hip joint; Humans; Knee; Male; Medicine; Medicine & Public Health; Middle Aged; Nerve Compression Syndromes - diagnosis; Orthopedics; Pain; Physical Examination; Physical therapy; Probability; Reproducibility of Results; Retrospective Studies; Sciatic Nerve; Sensitivity and Specificity; Surgeons; Surgery; Young Adult; United States > US; Pittsburgh Pennsylvania; Sensitivity; Specificity; Piriformis syndrome; Sciatica
• DOI: 10.1007/s00167-013-2758-7
• ISSN: 0942-2056; 1433-7347

Purpose The purpose of this study was to determine the diagnostic accuracy of the straight leg raise (SLR), active piriformis, and seated piriformis stretch tests in identifying individuals with sciatic nerve entrapment. Methods Thirty-three individuals (female = 25 and male = 8) with a mean age of 43 years (range 15–64; SD ± 11 years) were included in the study. Twenty-three subjects had endoscopic findings of sciatic nerve entrapment. Ten subjects without entrapment during endoscopic assessment were used as a control group. The results of the SLR, active piriformis, and seated piriformis stretch tests were retrospectively reviewed for each subject and compared between both groups. The accuracy of these tests for the endoscopic finding of sciatic nerve entrapment was determined by calculating the sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio. Results The SLR had sensitivity of 0.15, specificity of 0.95, positive likelihood ratio of 3.20, negative likelihood ratio of 0.90, and diagnostic odds ratio of 3.59. The active piriformis test had sensitivity of 0.78, specificity of 0.80, positive likelihood ratio of 3.90, negative likelihood ratio of 0.27, and diagnostic odds ratio of 14.40. The seated piriformis stretch test had sensitivity of 0.52, specificity of 0.90, positive likelihood ratio of 5.22, negative likelihood ratio of 0.53, and diagnostic odds ratio of 9.82. The most accurate findings were obtained when the results of the active piriformis test and seated piriformis stretch test were combined, with sensitivity of 0.91, specificity of 0.80, positive likelihood ratio of 4.57, negative likelihood ratio of 0.11, and diagnostic odds ratio of 42.00. Conclusions The active piriformis and seated piriformis stretch tests can be used to help identify patients with and without sciatic nerve entrapment in the deep gluteal region. Level of evidence II.