Lamb boning -- an occupational cause of carpal tunnel syndrome?

Whether an occupation can cause carpal tunnel syndrome requiring carpal tunnel decompression (CTD) is contentious. We compared the demographics and incidence rates in lamb-freezing workers with the general population who had CTD. In the general population there were 1002 (63%) females and 583 (37%) males, mean age 48 years, and the rate of CTD was 1.36/1000 per annum. In lamb-freezing workers there were 225 males (mean age 38.4 years) and 60 females (mean age 44.6 years); most workers required CTD in their first three seasons. Compared with the general population, the incidence rate ratios in all freezing workers was 16.8; boners, 51.6; meat packers, 22.8; and slaughtermen, 5.4. All groups had a greater rate of CTD than the general population. This study suggests that carpal tunnel syndrome can be directly caused by an occupation.