Clinical tests for assessing the presence and quality of the palmaris longus tendon: diagnostic accuracy of examination compared with ultrasound

Abstract

Various clinical tests are used to evaluate the palmaris longus tendon, but their accuracy is unknown. We assessed the accuracy of clinical tests (Schaeffer’s, Thompson’s, Mishra-I, Mishra-II) against ultrasound as the reference standard. We hypothesized that Schaeffer’s was most accurate and that examination can reliably assess the palmaris longus tendon’s length. Ninety-six wrists were examined clinically and evaluated with ultrasound by radiologists who were blinded to examination results. We calculated diagnostic accuracy and agreement between length measurements. Sensitivity values were as follows: Schaeffer’s 94%, Mishra-I 100%, Mishra-II 100%, Thompson’s 72%. Specificity values were as follows: Schaeffer’s 94%, Mishra-I 83%, Mishra-II 89%, Thompson’s 91%. Intraclass correlation coefficient between palmaris longus tendon length measurement on examination and ultrasound was 0.54. Schaeffer’s test accurately detected this tendon with >90% sensitivity and specificity, but clinical examination less reliably measured palmaris longus tendon length. Ultrasound may be a useful adjunct to assess potential graft length preoperatively. Level of evidence: I