High values of pelvic incidence: A possible risk factor for zigoapophyseal facet arthrosis in young.

In humans the acquisition of the bipedalism caused different structural changes to achieve the new functional demands. In particular, several changes have occurred in the spine and pelvis. In recent years the sagittal morphology of the spine and pelvis has become one of the most focused topics in spine research. The sample consists of 348 volunteers, with no history of low back pain, without any previous major trauma at the spine or at the pelvis. Aged between 20 and 29 years. The presence and severity of zygoapophyseal facet arthrosis were investigated in accordance with Pathria's classification (it considered four parameters: width of interarticular space, the presence of osteophytes, the presence of facet hypertrophy and presence of areas of bone erosion). Volunteers were divided into two group based on sagittal balance subtype classified by Roussouly in 2005. 98 volunteers (35.76%) belongs to group A (subtype I and II), and 176 volunteers (64.24%) belongs to group III and IV. The different weight distribution in the lumbar spine suggests that different subtype of sagittal balance could develop zygoapophyseal facet arthrosis more frequently. Considering the different Groups, a statistically significant difference was found: people belonging in group B (subtype III and IV), shows a prevalence of 36,36% compared with a prevalence of 24.5% for group A (subtype I and II).