Carpal tunnel syndrome in railroad workers

Objective: To determine, within a specific industry, if carpal tunnel syndrome (CTS) is associated with job classification or other personal risk factors. To determine if surgical intervention for the treatment of CTS is indicated on the basis of electrodiagnostic criteria. Design: More than 2500 claimants who screened positive for CTS were subjected to a formal history, physical examination, and electrodiagnostic studies. A total of 900 subjects were randomly selected for this study. The presence of CTS was determined by a method of comparing median minus ulnar nerve distal latency differential (MUD). Results: There was a statistically significant relationship between CTS and body mass index (P < 0.001), wrist index (P < 0.001), and age (P < 0.001). A total of 43.4% of the participants (391/900) and 38.6% of the wrists (694/1800) had either positive or borderline findings for CTS. There was no difference between the left and right hands. There was no association between job classification and the presence of CTS. Using MUD criteria, more than half of the participants presumed to have CTS did not meet the requirements for diagnosis. Applying the same MUD criteria to all surgical cases, the indication for surgery could not be determined in one-third of the cases (33%, 83/248). Conclusions: In the population claiming CTS caused by railroad occupations, there was a significant association between CTS and body mass index, age, and wrist index, but not job classification. More than half of the study group and one-third of the surgical subset had normal MUD data.