Tomohiro Banno1, Hideyuki Arima2, Tomohiko Hasegawa2, Yu Yamato2, Daisuke Togawa2, Go Yoshida2, Tatsuya Yasuda3, Shin Oe2, Yuki Mihara2, Hiroki Ushirozako2, Yukihiro Matsuyama2. 1. Department of Orthopaedic Surgery, Hamamatsu University School of Medicine, 〒431-3192 Shizuoka Prefecture, Hamamatsu, Higashi Ward, Handayama, Japan. Electronic address: tomohiro.banno0311@gmail.com. 2. Department of Orthopaedic Surgery, Hamamatsu University School of Medicine, 〒431-3192 Shizuoka Prefecture, Hamamatsu, Higashi Ward, Handayama, Japan. 3. Department of Orthopaedic Surgery, Hamamatsu Medical Center, 328 Tomitsukacho, Naka Ward, Hamamatsu, Shizuoka Prefecture 432-8580, Japan.
Abstract
OBJECTIVE: We investigated the relationship between cross-sectional area (CSA) of paravertebral muscle and trunk tilt at standing and walking in adult spinal deformity (ASD) surgery. SUMMARY OF BACKGROUND DATA: Although the importance of back muscles for the development of spinal kyphosis was well described, the influence on maintaining the sagittal balance was unclear. METHODS: Forty-five female patients (mean age, 68.8 years) with ASD were studied. We measured sagittal vertical axis [SVA], pelvic tilt [PT], and pelvic incidence-lumbar lordosis [PI-LL]) by lateral spine radiograph. For the assessment of trunk tilt standing-trunk tilt angle (STA) by lateral standing radiograph, gait-trunk tilt angle (GTA) by lateral gait images, and the increasing trunk tilt angle (ITA) by subtracting the STA from the GTA were calculated. Using L1/2 and L4/5 axial MRI, the CSAs of bilateral multifidus muscles (MF) and elector spinae (ES) removed fat by Image J software were calculated. We examined the correlation between trunk tilt angle (STA, GTA, and ITA) and spinopelvic parameters (SVA, PT, and PI minus LL) and also the correlation among muscle CSA, trunk tilt angle (STA, GTA, and ITA), and Oswestry Disability Index (ODI). RESULTS: The mean STA, GTA, and ITA were 4.2°, 13.0°, and 8.8°, respectively. The CSAs of back muscles were 278 mm2 at L1/2 MF, 1,687 mm2 at L1/2 ES, 636 mm2 at L4/5 MF, and 1,355 mm2 at L4/5 ES, respectively. Trunk tilt angle had significant relations with spinopelvic parameters. Concerning about muscle CSA, significant correlations were observed between STA and L4/5 MF (r = -0.517), GTA and L1/2 ES (r = -0.461) and L4/5 MF (r = -0.476), and ITA and L1/2 ES(r = -0.429). ODI showed significant correlation with STA and GTA. CONCLUSIONS: Paravertebral muscles were crucial to keep upright posture during walking as well as standing.
OBJECTIVE: We investigated the relationship between cross-sectional area (CSA) of paravertebral muscle and trunk tilt at standing and walking in adult spinal deformity (ASD) surgery. SUMMARY OF BACKGROUND DATA: Although the importance of back muscles for the development of spinal kyphosis was well described, the influence on maintaining the sagittal balance was unclear. METHODS: Forty-five female patients (mean age, 68.8 years) with ASD were studied. We measured sagittal vertical axis [SVA], pelvic tilt [PT], and pelvic incidence-lumbar lordosis [PI-LL]) by lateral spine radiograph. For the assessment of trunk tilt standing-trunk tilt angle (STA) by lateral standing radiograph, gait-trunk tilt angle (GTA) by lateral gait images, and the increasing trunk tilt angle (ITA) by subtracting the STA from the GTA were calculated. Using L1/2 and L4/5 axial MRI, the CSAs of bilateral multifidus muscles (MF) and elector spinae (ES) removed fat by Image J software were calculated. We examined the correlation between trunk tilt angle (STA, GTA, and ITA) and spinopelvic parameters (SVA, PT, and PI minus LL) and also the correlation among muscle CSA, trunk tilt angle (STA, GTA, and ITA), and Oswestry Disability Index (ODI). RESULTS: The mean STA, GTA, and ITA were 4.2°, 13.0°, and 8.8°, respectively. The CSAs of back muscles were 278 mm2 at L1/2 MF, 1,687 mm2 at L1/2 ES, 636 mm2 at L4/5 MF, and 1,355 mm2 at L4/5 ES, respectively. Trunk tilt angle had significant relations with spinopelvic parameters. Concerning about muscle CSA, significant correlations were observed between STA and L4/5 MF (r = -0.517), GTA and L1/2 ES (r = -0.461) and L4/5 MF (r = -0.476), and ITA and L1/2 ES(r = -0.429). ODI showed significant correlation with STA and GTA. CONCLUSIONS: Paravertebral muscles were crucial to keep upright posture during walking as well as standing.