Yann Philippe Charles1, Solène Prost2, Sébastien Pesenti3, Brice Ilharreborde4, Eloïse Bauduin5, Féthi Laouissat6, Guillaume Riouallon7, Stéphane Wolff7, Vincent Challier8, Ibrahim Obeid9, Louis Boissière9, Emmanuelle Ferrero10, Federico Solla11, Jean-Charles Le Huec12, Stéphane Bourret12, Joe Faddoul13, Georges Naïm Abi Lahoud13, Vincent Fière14, Michiel Vande Kerckhove14, Matthieu Campana4, Jonathan Lebhar15, Hadrien Giorgi16, Aymeric Faure16, Erik André Sauleau17, Benjamin Blondel2. 1. Service de Chirurgie du Rachis, Hôpitaux Universitaires de Strasbourg, Université de Strasbourg, 1 Avenue Molière, 67200, Strasbourg, France. YannPhilippe.CHARLES@chru-strasbourg.fr. 2. Unité de Chirurgie Rachidienne, CHU Timone, Aix-Marseille Université, Marseille, France. 3. Service d'Orthopédie Pédiatrique, CHU Timone, Aix-Marseille Université, Marseille, France. 4. Service de Chirurgie Orthopédique Pédiatrique, AP-HP, CHU Robert Debré, Université de Paris, Paris, France. 5. Service de Chirurgie Orthopédique et Traumatologie, Hôpital Maison Blanche, CHU de Reims, Reims, France. 6. Hôpital Privé de L'Est Lyonnais, Saint-Priest, France. 7. Service de Chirurgie Orthopédique et Traumatolgique, Groupe Hospitalier Paris Saint Joseph, Paris, France. 8. Hôpital Privé du Dos Francheville, Périgueux, France. 9. Clinique du Dos Jean Villar, Bruges, France. 10. Service de Chirurgie Orthopédique de la Colonne Vertébrale, AP-HP, Hôpital Européen Georges-Pompidou, Université de Paris, Paris, France. 11. Service d'Orthopédie Pédiatrique, Fondation Lenval, Nice, France. 12. Polyclinique Bordeaux Nord Aquitaine, Université de Bordeaux, Bordeaux, France. 13. Institut de la Colonne Vertébrale et des Neurosciences, Centre Médico-Chirurgical Bizet, Paris, France. 14. Centre Orthopédique Santy, Unité du Rachis, Lyon, France. 15. Institut Locomoteur de L'Ouest Rachis, Centre Hospitalier Privé Saint-Grégoire, Saint-Grégoire, France. 16. Institut Méditerranéen du Dos, Marseille, France. 17. Pôle Santé Publique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France.
Abstract
PURPOSE: The aim was to describe radiographic cervical sagittal alignment variations according to age, gender and pelvic incidence (PI) and to investigate relationships with thoracic alignment. METHODS: A total of 2599 individuals (5-93 years) without spinal deformity were studied. Cranial cervical parameters were: McGregor slope, occipita-C2 angle, McGregor-C2 lordosis and C1-C2 lordosis. Caudal cervical parameters were: C2-C7, cranial arch and caudal arch lordosis and C7- and T1-slope. A Bayesian inference compared parameter distributions. Correlations with spinopelvic and global alignment parameters were investigated. RESULTS: Among cranial cervical parameters, variations of McGregor slope were non-significant. McGregor-C2 lordosis and C1-C2 lordosis were smaller in males and increased significantly during growth, whereas the occipito-C2 angle decreased (Pr > 0.95). The occipito-C2 angle was larger and McGregor-C2 lordosis was smaller in low PI (Pr > 0.95). Among caudal cervical parameters, C2-C7 lordosis and C7- and T1-slope were larger in males and increased after 50 years (Pr > 0.95). Lordosis changes were non-significant in the cranial arch, whereas values increased in the caudal arch after 35 years (Pr > 0.95). Caudal parameter differences were non-significant between PI groups. Strong correlations existed between C2-C7, caudal arch lordosis, C7-slope, T1-slope and thoracic kyphosis. The sagittal vertical axis C2 correlated with caudal arch lordosis and T1-slope (ρ > 0.5; Pr > 0.95). CONCLUSION: Cervical alignment parameters vary according to age, gender and PI. In the cranial cervical spine, changes occur mainly during growth. In the caudal cervical spine, lordosis increases in the caudal arch, which is related to thoracic kyphosis increase with age. The caudal cervical arch acts as a compensatory segment by progressive extension, allowing horizontal gaze.
PURPOSE: The aim was to describe radiographic cervical sagittal alignment variations according to age, gender and pelvic incidence (PI) and to investigate relationships with thoracic alignment. METHODS: A total of 2599 individuals (5-93 years) without spinal deformity were studied. Cranial cervical parameters were: McGregor slope, occipita-C2 angle, McGregor-C2 lordosis and C1-C2 lordosis. Caudal cervical parameters were: C2-C7, cranial arch and caudal arch lordosis and C7- and T1-slope. A Bayesian inference compared parameter distributions. Correlations with spinopelvic and global alignment parameters were investigated. RESULTS: Among cranial cervical parameters, variations of McGregor slope were non-significant. McGregor-C2 lordosis and C1-C2 lordosis were smaller in males and increased significantly during growth, whereas the occipito-C2 angle decreased (Pr > 0.95). The occipito-C2 angle was larger and McGregor-C2 lordosis was smaller in low PI (Pr > 0.95). Among caudal cervical parameters, C2-C7 lordosis and C7- and T1-slope were larger in males and increased after 50 years (Pr > 0.95). Lordosis changes were non-significant in the cranial arch, whereas values increased in the caudal arch after 35 years (Pr > 0.95). Caudal parameter differences were non-significant between PI groups. Strong correlations existed between C2-C7, caudal arch lordosis, C7-slope, T1-slope and thoracic kyphosis. The sagittal vertical axis C2 correlated with caudal arch lordosis and T1-slope (ρ > 0.5; Pr > 0.95). CONCLUSION: Cervical alignment parameters vary according to age, gender and PI. In the cranial cervical spine, changes occur mainly during growth. In the caudal cervical spine, lordosis increases in the caudal arch, which is related to thoracic kyphosis increase with age. The caudal cervical arch acts as a compensatory segment by progressive extension, allowing horizontal gaze.