Registry for Evaluation of Lumbar Arthrodesis Sagittal alignmEnt

The study goal of RELApSE is to evaluate the relationships between radiological data and patients reported outcome. Restoration of Sagittal alignment and Pelvic Index (PI)-Lumbar Lordosis (LL) mismatch is closely associated with a better outcome in spinal deformities, while there is still a lack of consistent evidence regarding short-segment arthrodesis for lumbar degenerative pathology. Over the past 10 years, an increasing number of publications reported associations between the presence of PI-LL mismatch, reduced lumbar lordosis, increased pelvic tilt, and outcome of lumbar arthrodesis for degenerative lumbar disease. Other authors, on the other hand, reported an absence of correlation between the same parameters and clinical outcome. In addition, several authors have been reported evidence regarding association of adjacent level disc degeneration and elevated pelvic tilt, persistent PI-LL mismatch and altered LL4-S1/LL ratio. Also on this aspect, other studies identify different elements as predisposing factors for junctional pathology. The definitive value for lumbar degenerative pathology of these aspects in relation to the surgical outcome remains to be clarified without consolidated evidence. The RELApSE study is the first prospective and multicenter study on these topics. Starting from a very heterogeneous population in terms of clinical conditions, pathology and surgical treatment options, the study methods is to make the population homogeneous on some data available in all patients end that can be analyzed independently. These data are: pelvic parameters (pelvic incidence, pelvic tilt, sacral slope), segmental lumbar lordosis (LS), global lumbar lordosis (LL), PI-LL mismatch and L4-S1/LL lordosis ratio; clinical results based on administered questionnaires (Oswestry disability index, Short Form-12) and overall outcome assessment at FU (6 point scale: excellent (completely resolved symptoms), good (good clinical improvement, minor symptoms), fair (improv