Carpal Tunnel Syndrome among workers in a condom industry

Kang, Joong Koo; Paek, Do Myung; Lee, Young Jung; Ma, Hyeo Il; Song, Mi A; Lee, Hong Ki; Choi, Jung Keun

Abstract

The objectives of this study are to investigate the prevalence of occupation related carpal tunnel syndrome(CTS) among workers in a condom industry; to analyse the sensitivity and specificity of clinical signs or symptoms such as hand diagram, Tinel's sign and Phalen's sign in carpal tunnel syndrome; and to test vibration threshold test using audiometry as a technically easy and noninvasive method in the diagnosis of carpal tunnel syndrome in stead of nerve conduction velocity(NCV). The study group was divided into exposed group(39 cases)and non-exposed group(48 cases) based on whether or not excessive use of wrist movements exist. 1. There are statistically significant differences in symptoms and signs of carpal tunnel syndrome such as hand diagram, Tinel's sign and Phalen's sign between exposed and non-exposed group(p<0.05). 2. Six cases(9 hands) were confirmed as carpal tunnel syndrome by NCV. Five cases(7 hands) belonged to exposed group, 1 case(2 hands) to nonexposed group. As there are significant differences in prevalence of carpal tunnel syndrome between two groups(p<0.05), excessive use of wrist in occupation is a risk factor of carpal tunnel syndrome. 3. When we use NCV as a gold standard in the diagnosis of carpal tunnel syndrome, sensitivity and specificity of hand diagram, Tinel's sign and Phalen's sign is as followed; hand diagram; sensitivity 88.9%, specificity 84.2%. Tinel's sign; sensitivity 55.6%, specificity 72.8%. Phalen's sign; sensitivity 14.3%, specificity 88.4%. Among above clinical signs and symptoms, hand diagram is the best clinical screening test. 4. The differences of vibration threshold between median and ulnar nerve at the same time are useful in the diagnosis of carpal tunnel syndrome but the time change of vibration threshold of median nerve over time are not sensitive enough. It is concluded that vibration threshold between median and ulnar nerve at the same time can be used as a supplementary or alternative criterion to indicate that the nerve dysfunction is located in the carpal tunnel.