INTRODUCTION: Retrospective analysis of the spino‐pelvic alignment in a population of 193 cases with a lumbar degenerative disease and compared to 54 normal control group. Several previous publications reported the analysis of spino‐pelvic alignment in the normal and low back pain population. Data suggested that patients with lumbar disease have variations of sagittal alignmnent such as less lordosis and pelvic shape. The objective of this study was to anlyse spino‐pelvic parameters including pelvis shape and the correlation and compare these patients with control group of normal volunteers.
METHODS: We analysed five different lumbar degenerative desease: disc herniation(DH),n=61; degenerative spondylolisthesis(DSL),n=41; lumbar canal stenosis (LCS), n=35; lumbarlysis (LL), n=20; low back pain, n=36. Spino‐pelvic alignment was analysed pre‐operatively on full spine radiographs. Spino‐pelvic parameters were measured as positioning of C7 plumb line (SVC), lumbar lordotic angle (LLA), sacral slope (SS), pelvic angle (PA) and pelvic morphologic angle (PRS1).
RESULTS & DISCUSSION: Concerning the pelvis shape, patients with DD and LL demonstrated to have significant lower PRS1 as 32.6± 9.0 and 32.1± 10.9° respectively, than control group (37.5± 8.7°). The these five groups (LCS, DS,LL, LDH, LBP) of patients were characterized by significant variations vs control in spino‐pelvic alignment: anterior translation of SVA (48.6, 45.2,27.6 vs 2.9mm in LCS, DS, LL), loss of LLA(19.9 vs 30° in LCS), decrease of SS(26.6, 29.2 vs 35 ° in LCS, DS), increase of SS(36.4 °in LL), increase of PA (24.6, 28.0 vs 17.4 °in LCS, DS). Measurement of the pelvic morphologic angle and spinal parameters permitted to understand variations of spino‐pelvic parameters in a population of patients. Our results suggested that the lower PRS1 could be one of risk factor to occur DS and LL.