Stéphane Bourret1, Meghan Cerpa2, Michael P Kelly3, Kazuhiro Hasegawa4, Hwee Weng Dennis Hey5, Hee-Kit Wong5, Gabriel Liu5, Zeeshan M Sardar2, Hend Riahi6, Lawrence G Lenke2, Jean Charles Le Huec7. 1. VERTEBRA Institute, Polyclinique Bordeaux Nord Aquitaine, 33 rue du Dr Finlay, 33077, Bordeaux Cedex, France. 2. Department of Orthopedic Surgery, Columbia University Medical Center, The Spine Hospital at New York Presbyterian, New York, USA. 3. Department of Orthopaedic Surgery, Washington University, St. Louis, MO, USA. 4. Niigata Spine Surgery Center, Niigata City, Japan. 5. Department of Orthopedic Surgery, National University Hospital (Singapore), Singapore, Singapore. 6. Institut Kassab D'orthopédie, Ksar Said La Manouba, Tunis, Tunisia. 7. VERTEBRA Institute, Polyclinique Bordeaux Nord Aquitaine, 33 rue du Dr Finlay, 33077, Bordeaux Cedex, France. jclehuec1@gmail.com.
Abstract
PURPOSE: Previous studies on adults with degenerative scoliosis (ADS) have been fixed the threshold of PI-LL mismatch less than 10° for achieving good clinical outcomes. Recent studies discussed that PI-LL mismatch should consider individual pelvic incidence (PI) and should be set first in a normal population. The purpose of this study is to assess the variability of PI-LL mismatch according to PI in an asymptomatic population. METHODS: Full-body low dose stereoradiographic evaluation was done in a multi-ethnic cohort of 468 asymptomatic adult volunteers. Patients were clustered in three groups depending on individual PI values: PI < 45°, 45° < PI < 60° and PI > 60°. 3D measurements were performed using a commercially available 2D/3D modeling software to establish a correlation of PI with other spinopelvic parameters. ANOVA and Tukey's HSD for post-hoc analysis were used to determine the differences between the three groups. RESULTS: In our asymptomatic population, the mean value of PI-LL mismatch is - 5.4° ± 10.7°. Clusterization of the population reveals significant differences in the distribution of L1S1 lordosis, pelvic tilt and PI-LL with positive linear correlation according to PI values. As an interestingly result, PI-LL mismatch is equal to 0° when PI is around 64°. CONCLUSIONS: The present study demonstrated that PI-LL mismatch is negative in an asymptomatic population (- 5.4° ± 10.7°) and the value should be customized to each patient to be able to restore the appropriate lordosis in ADS. The PI-LL mismatch is given by the formula PI-LL = - 28.5 + 0.44 × PI.
PURPOSE: Previous studies on adults with degenerative scoliosis (ADS) have been fixed the threshold of PI-LL mismatch less than 10° for achieving good clinical outcomes. Recent studies discussed that PI-LL mismatch should consider individual pelvic incidence (PI) and should be set first in a normal population. The purpose of this study is to assess the variability of PI-LL mismatch according to PI in an asymptomatic population. METHODS: Full-body low dose stereoradiographic evaluation was done in a multi-ethnic cohort of 468 asymptomatic adult volunteers. Patients were clustered in three groups depending on individual PI values: PI < 45°, 45° < PI < 60° and PI > 60°. 3D measurements were performed using a commercially available 2D/3D modeling software to establish a correlation of PI with other spinopelvic parameters. ANOVA and Tukey's HSD for post-hoc analysis were used to determine the differences between the three groups. RESULTS: In our asymptomatic population, the mean value of PI-LL mismatch is - 5.4° ± 10.7°. Clusterization of the population reveals significant differences in the distribution of L1S1 lordosis, pelvic tilt and PI-LL with positive linear correlation according to PI values. As an interestingly result, PI-LL mismatch is equal to 0° when PI is around 64°. CONCLUSIONS: The present study demonstrated that PI-LL mismatch is negative in an asymptomatic population (- 5.4° ± 10.7°) and the value should be customized to each patient to be able to restore the appropriate lordosis in ADS. The PI-LL mismatch is given by the formula PI-LL = - 28.5 + 0.44 × PI.
Authors: Caglar Yilgor; Nuray Sogunmez; Yasemin Yavuz; Kadir Abul; Louis Boissiére; Sleiman Haddad; Ibrahim Obeid; Frank Kleinstück; Francisco Javier Sánchez Pérez-Grueso; Emre Acaroğlu; Anne F Mannion; Ferran Pellise; Ahmet Alanay Journal: Neurosurg Focus Date: 2017-12 Impact factor: 4.047