Physical Exam Measures have a Low Yield in Employment Screening for Carpal Tunnel Syndrome

Objectives: Employment screening for CTS using the physical exam is a common practice with unknown yield. Our goal was to evaluate physical exam measures used to screen for carpal tunnel syndrome (CTS) in a cohort of newly-hired workers.

Methods: The study population was a cohort of 1108 newly-hired workers who were participating in a prospective study of incident CTS (The PrediCTS study). Baseline testing included a symptom questionnaire and physical exam as well as nerve conduction testing of the median and ulnar nerves bilaterally. Exam measures included Semmes-Weinstein sensory testing, hand grip strength, and wrist anthropometrics; palpation at the elbow and provocation of the wrist extensors, wrist flexors, and radial tunnel using the long finger test; and Tinel's test, Phalen's test, and Finkelstein's test. We also analyzed the association between each physical exam and three outcomes: median mononeuropathy, CTS hand symptoms, and a case definition of CTS.

Results: Lateral epicondyle palpation, Phalen's test, and Semmes-Weinstein testing showed weak associations with each outcome. Only Semmes-Weinstein testing had a sensitivity value above 30% for any outcome (76.9% for our CTS case definition). Due to the low prevalence of CTS in this newly-hired population (1.2% prevalence of CTS), positive predictive values were low (<19%) and negative predictive values were high (>90%).

Conclusion: The physical exam has a low yield when screening a population of newly-hired workers for CTS. Post-offer pre-placement screening for CTS using the physical exam should be reevaluated in light of these and other data.