[Spino-pelvic sagittal parameters in an asymptomatic population in Argentina].

Objectives: To assess and describe spinal and pelvic sagittal parameters in a series of 100 Argentinian volunteers.

Methods: Lateral full-spine X-rays were obtained prospectively from 100 volunteers (30 males and 70 females), average age 34.1 years. All the volunteers were asymptomatic at the time of the study. Full-length left lateral spine radiographs (36'' cassette) were made using Kodak Elite CR equipment. The authors made determinations for the digital X-rays using Surgimap® , version 2.2.9.9.2. The following parameters were recorded: C7 SVA, C2-C7 CL, TK, LL, TPA, T1SPi, PI, PT, SS, L4-S1 angle, L1-L4 angle, PI-LL mismatch and CTPA. The data were analyzed using Medcalc 11.2 software. Descriptive statistics were calculated for each parameter according to its own measure score and distribution. Estimates of 95% reference and confidence intervals were calculated for each parameter. P = 0.05 was set as the threshold for statistical significance. Volunteers were classified using the Roussouly morphometric classification system.

Results: Respective means for the above-listed variables were: CL -10.04, TK 30.14, T1SPi -6.5, L1-L4 -12.45, L4-S1 -46.16, CTPA 2.5, TPA 4.65, PT 11.22, PI 48.04, LL -59. 10, PI-LL -11.11, C7 SVA mm -23.68. Plus/minus two standard deviations (SD) for the variables were: CL (-33.26, 13.12); TK (17.15, 43.30); T1SPi (-11.78, -1.25), L1-L4 (-25.55, 0.25), L4-S1 (-64.44, -27.55), CTPA (0.33, 4.80), TPA (-8.64, 18.22), PT (-1.99, 24.75), PI (25.23, 71.44), LL (-78.74, -39.89), PI-LL (-29.10, 7.04), and C7 SVA mm (-79.45, 32.08).

Conclusions: In this prospective series of 100 adult volunteers, normal values for spinal and pelvic sagittal parameters were determined in Argentinian adults.