Matsumoto Koji, Hoshino Masahiro, Omori Keita, Igarashi Hidetoshi, Tsuruta Takashi, Yamasaki Koji, Matsuzaki Hiromi, Iriuchishima Takanori, Tokuhashi Yasuaki
Department of Orthopaedic Surgery, Nihon University School of Medicine, 30-1 Oyaguchikamimati Itabashi-ku, Tokyo 173-8610, Japan; Department of Orthopaedic Surgery, Sonoda Medical Institute Tokyo Spine Center, 2-5-10 Ikohoncyo Adati-ku, Tokyo 121-0807, Japan.
Department of Orthopaedic Surgery, Sonoda Medical Institute Tokyo Spine Center, 2-5-10 Ikohoncyo Adati-ku, Tokyo 121-0807, Japan.
J Orthop Sci. 2018 Mar;23(2):253-257. doi: 10.1016/j.jos.2017.12.007. Epub 2018 Jan 6.
It remains unclear whether long fusion including lumbar-sacral fixation is needed in corrective surgery to obtain good global sagittal balance (GSB) for the treatment of traumatic thoracolumbar kyphotic spine deformity. The purposes of this study were to evaluate compensatory mechanism of the spine after corrective surgery without lumbar-sacral fixation and to evaluate the parameters affecting the achievement of good GSB post-operatively.
Twenty (20) subjects requiring corrective surgery (distal end of fixation was L3) were included in this study. The radiographic parameters were measured pre-operatively and at one month after surgery. Sagittal Vertical Axis (SVA), Lumber Lordosis angle altered by fracture (fLL), Thoracic Kyphosis angle altered by fracture (fTK), Pelvic Tilt (PT), Sacral Slope (SS), Pelvic Incidence (PI), Segmental Lumbar Lordosis (sLL: L3-S/L4-S), and local kyphotic angle were measured. The correlation between correction of local kyphotic angle (CLA) and the change in radiographic parameters was evaluated. Post-operatively, subjects with SVA<50 mm and PI-fLL<10°were regarded as the "good GSB group (G group). The radiographic parameters affecting the achievement of G group were statistically evaluated.
fLL, sLL:L3-S and sLL:L4-S were decreased indirectly because the local kyphosis was corrected directly (CLA: 26.5 ± 8.6°) (P < 0.001). CLA and the change in fLL showed significant correlation (r = 0.821), the regression equation being: Y = -0.63X+3.31 (Y: The change in fLL, X: CLA). The radiographic parameters significantly affecting the achievement of G group were: SVA, PT, PI-fLL, sLL: L3-S, and sLL: L4-S (P < 0.01).
The main compensatory mechanism was the decrease of lordosis in the lumbar spine. fLL was decreased to approximately 60% of CLA after surgery. SVA was not corrected by the compensatory mechanism.
