General Session: Cervical Degenerative - Hall F

Presented by: D. Kitumba

Author(s):

D. Kitumba(1,2), R. Reinas(1), O. Alves(1)

(1) Centro Hospitalar Vila Nova de Gaia, Neurocirurgia, Vila Nova de Gaia, Portugal
(2) Faculdade de Medicina da Universidade Agostinho Neto, Luanda, Angola

Abstract

Summary: Few studies evaluate the impact of fixations surgery around C0-C1-C2 on overall cervical alignment.

Objective: To analyse the influence that C0-C1-C2 fixations has on segmental (C0-C1-C2) and global cervical (C2-C7) alignment.

Methods: We retrospectively evaluated patients with high cervical spine instability that underwent C0-C2 or C1-C2 posterior fixations. Data were collected from pre and postoperatively plane radiographic exams on neutral position at last follow-up. The primary radiological outcomes were: C0-C1 angle, C1-C2 angle, C0-C2 angle, C2-C7 angle, cervical sagittal vertical alignment (cSVA) and T1 slope, all parameters measured using Sectra Corporation Software.

Results: Sixteen (16) consecutive patients were included with a mean age of 60,7 years (range 24 - 80 years), 10 females and 5 males. All patients were affected by atlanto-axial instability principally due to congenital malformation (62,6%) or degenerative disease (24,8%). Nine patients (60%) underwent C0-C2 fixation and six (40%) C1-2 fixation, and a mean follow up of 21,46 months were accomplished. C1-C2 fixations resulted on an increase of C1-C2 angle (mean increase 10,3º; range -13º to 24,2º) and a slight decrease of the C0-C1 angle (mean -4,5º; ranging from -24,5º to 17,3º). In contrast, C0-C2 fixation caused minimal impact on both C0-C1 angle (mean -0,33º; range -8,80º to 16,40º) and C1-C2 angle (mean -0,30º; range -9,60º to 7,10º). Focusing on subaxial sagittal alignment, C1-C2 and C0-C2 fixations showed no difference on C2-C7 angle (mean -4,08º versus -5,29º, respectively) and on T1-Slope (mean -4,03 versus mean -2,44), while affecting differently cSVA (means 11,01mm versus - 2,15mm).

Conclusions: Regarding the functional unit C0-C2, only C1-C2 fixation impacts on segmental C0-C2 angle due almost exclusively to a lordotic change in C1-C2 angle. As for C2-C7 both induce slight compensatory kyphotic curvature. The most distinctive feature between the two types of operation is a change in the cSVA: C0-C2 tends to increase it whereas C1-C2 fixation has only a minimal effect. Pre-operative cSVA should be taken into account when choosing the most appropriate fixation option.

Keywords: C0-C2 fixation; C1-C2 fixation; subaxial sagittal alignment.