Segmental roentgenographic analysis of vertebral inclination on sagittal plane in asymptomatic versus chronic low back pain patients

Two homogenous groups of 120 volunteers and 120 low back pain (LBP) patient s, age range 20-79 years, underwent a prospective roentgenographic seg ment al vertebral analysis of the thoracic and lumbar spine to compare several r oentgenographic parameters useful for planning spine surgery. The following roentgenographic parameters were measured: thoracic kyphosis, lumbar lordo sis, sacral inclination, distal lordosis (L4-S1), inclination of each verte bra from T4-S1, and relative vertebral inclination between adjacent vertebr ae. Thoracic kyphosis increased (p < 0.0001) and sacral inclination decreas ed (p < 0.05) with age in the control group. Increased thoracic kyphosis co rrelated with decreased lumbar lordosis after the sixth decade in the contr ol group (p < 0.01), less so in the LBP group (p < 0.05). Increased thoraci c kyphosis was seen more in the LBP group than in the controls, but signifi cantly solely in the sixth decade (p < 0.01). Lumbar lordosis was more incr eased in the controls than in the LBP group but significantly solely in the sixth decade (p < 0.001). The L5-S1 segmental lordosis was much more in th e LBP patients than in the controls (p < 0.001). Lumbar lordosis tvas stron gly correlated with sacral inclination in both groups (p < 0.0001) and it w as significantly greater in the controls, particularly in the sixth decade (p < 0.001). Sacral inclination was significantly more in the female than i n male volunteers (p < 0.05), Distal lordosis (L4-S1) represents 55% and 49 % of total lumbar lordosis in controls and low back patients, respectively. Spine surgeons frequently deal with sagittal spinal deformities and the de viations of sagittal spinal curvatures and vertebral inclination in the sag ittal plane, both in normal subjects and LBP patients should be clinically helpful.