Disabling spondyloarthrosis risk factors in valley of Mexico workers.

Background: The objective of this study was to describe the most prevalent physically disabling conditions for insured workers belonging to the Mexican Social Security Institute (IMSS) in the Valley of Mexico and to identify risk factors for disabling spondyloarthrosis.
Methods: Retrospective cases and prevalent controls from IMSS clinics in the Mexico City metropolitan area were studied. Eighty cases were IMSS workers reporting disability due to spondyloarthrosis; 80 controls were active workers at the same workplace and shared the economic activity of the cases. The 1995 IMSS Disability Report was reviewed. From this report congenital conditions of the musculoskeletal system, obesity, history of trauma, and sociodemographic patient characteristics were assessed.
Results: The most important risk factors were a history of spina bifida (odds ratio [OR] = 29.3, 95% confidence interval [95% CI] = 5.3-161; p = 0.0009), supernumerary vertebrae (OR = 21.3, 95% CI = 5.3-95; p = 0.0001), history of low back (lumbar) trauma (OR = 3.9, 95% CI = 1.9-8.3; p = 0.0004), flatfoot (OR = 11.7, 95% CI = 1.9-69, p = 0.02), and obesity (OR = 2.0, 95% CI = 1.06-4.03; p = 0.04).
Conclusions: A history of congenital deformity of the musculoskeletal system, spinal column trauma, and obesity were risk factors most associated with work disability due to spondyloarthrosis.