Chizuo Iwai1,2, Javier Pizones3, Louis Boissière1, Sreenath Jakinapally1, Çaglar Yilgor4, Daniel Larrieu1, Ferran Pellise5, Jean-Marc Vital1, Anouar Bourghli6, Ibrahim Obeid7. 1. Spine Unit 1, Bordeaux University Hospital, Place Amelie Raba-Leon, 33076, Bordeaux, France. 2. Department of Orthopaedic Surgery, Gifu University Graduate School of Medicine, Gifu, Japan. 3. Spine Surgery Unit, Hospital Universitario La Paz, Madrid, Spain. 4. Spine Surgery Unit, Acibadem Maslak Hospital, Istanbul, Turkey. 5. Spine Surgery Unit, Hospital Universitario Val Hebron, Barcelona, Spain. 6. Orthopedic and Spinal Surgery Department, Kingdom Hospital, Riyadh, Saudi Arabia. 7. Spine Unit 1, Bordeaux University Hospital, Place Amelie Raba-Leon, 33076, Bordeaux, France. ibrahim.obeid@gmail.com.
Abstract
PURPOSE: Sagittal lumbar apex has been demonstrated to be a key parameter in sagittal plane morphology. Our aim was to understand its behavior with postural changes, analyzing two different concepts of lumbar apex. MATERIALS AND METHODS: Prospective observational study with a cohort of patients presenting sagittal malalignment identified from a monocenter database of adult spinal deformities (ASD). Inclusion criteria were age > 30 years, SVA > 40 mm, and/or PT > 20. All patients had full-spine EOS radiographs in 2 different positions: (P1: natural position) and position 2 (P2: compensated position). Sagittal alignment, spinopelvic values, and two different methods of assessing lordosis apex location were analyzed in both P1 and P2 positions. Changes between P1 and P2 were compared using a paired t test with a significance level at p < 0.05. RESULTS: Twenty-five patients were recruited (21 women and 4 men). The mean age was 64.8 years (range 21-79). The patient's main compensation was based on an increase in the femoral shaft angle, and pelvic retroversion, with a subsequent decrease in sacral slope, and therefore of the lower lumbar arc. When the lumbar apex was calculated as the most anterior point touching the vertical line in a lateral radiograph, postural compensation changes modified its location usually shifting it to a more caudal position. When the lumbar apex was assessed as the most distant point of the global lumbar lordosis, its position remained stable regardless of compensation. CONCLUSIONS: Postural changes can modify the location of the lumbar apex when understanding its location as the cornerstone of sagittal plane harmonic distribution. This concept can be useful as an additional sign to assess compensation. However, if the lumbar apex was calculated as the angular point of the global lordosis, its position remained stable regardless of postural changes. This concept can help to mold lumbar lordosis in ASD surgery. LEVEL OF EVIDENCE IV: Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding.
PURPOSE: Sagittal lumbar apex has been demonstrated to be a key parameter in sagittal plane morphology. Our aim was to understand its behavior with postural changes, analyzing two different concepts of lumbar apex. MATERIALS AND METHODS: Prospective observational study with a cohort of patients presenting sagittal malalignment identified from a monocenter database of adult spinal deformities (ASD). Inclusion criteria were age > 30 years, SVA > 40 mm, and/or PT > 20. All patients had full-spine EOS radiographs in 2 different positions: (P1: natural position) and position 2 (P2: compensated position). Sagittal alignment, spinopelvic values, and two different methods of assessing lordosis apex location were analyzed in both P1 and P2 positions. Changes between P1 and P2 were compared using a paired t test with a significance level at p < 0.05. RESULTS: Twenty-five patients were recruited (21 women and 4 men). The mean age was 64.8 years (range 21-79). The patient's main compensation was based on an increase in the femoral shaft angle, and pelvic retroversion, with a subsequent decrease in sacral slope, and therefore of the lower lumbar arc. When the lumbar apex was calculated as the most anterior point touching the vertical line in a lateral radiograph, postural compensation changes modified its location usually shifting it to a more caudal position. When the lumbar apex was assessed as the most distant point of the global lumbar lordosis, its position remained stable regardless of compensation. CONCLUSIONS: Postural changes can modify the location of the lumbar apex when understanding its location as the cornerstone of sagittal plane harmonic distribution. This concept can be useful as an additional sign to assess compensation. However, if the lumbar apex was calculated as the angular point of the global lordosis, its position remained stable regardless of postural changes. This concept can help to mold lumbar lordosis in ASD surgery. LEVEL OF EVIDENCE IV: Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding.
Authors: Javier Pizones; Francisco Javier Sánchez Perez-Grueso; Lucía Moreno-Manzanaro; Alba Vila-Casademunt; Louis Boissiere; Caglar Yilgor; Nicomedes Fernández-Baíllo; José Miguel Sánchez-Márquez; Gloria Talavera; Frank Kleinstück; Emre R Acaroglu; Ahmet Alanay; Ferran Pellisé; Ibrahim Obeid Journal: Spine Deform Date: 2020-01-08
Authors: Amer Sebaaly; Clément Sylvestre; Yehya El Quehtani; Guillaume Riouallon; Daniel Larrieu; Louis Boissiere; Jean Paul Steib; Pierre Roussouly; Stéphane Wolff; Ibrahim Obeid Journal: Clin Spine Surg Date: 2018-04 Impact factor: 1.876
Authors: William C Horton; Courtney W Brown; Keith H Bridwell; Steven D Glassman; Se-Il Suk; Charles W Cha Journal: Spine (Phila Pa 1976) Date: 2005-02-15 Impact factor: 3.468