Limited morbidity and possible radiographic benefit of C2 vs. subaxial cervical upper-most instrumented vertebrae

Passias, Peter G

Bortz, Cole A

Segreto, Frank

Horn, Samantha

Pierce, Katherine E

Alas, Haddy

Brown, Avery E

Lafage, Renaud

Lafage, Virginie

Smith, Justin S

Line, Breton

Eastlack, Robert

Sciubba, Daniel M

Klineberg, Eric O

Soroceanu, Alexandra

Burton, Douglas C

Schwab, Frank J

Bess, Shay

Shaffrey, Christopher I

Ames, Christopher P

2023-06-20T13:15:06Z

2023-06-20T13:15:06Z

2019-06-29

2023-06-20T13:15:05Z

Background: The study aims to evaluate differences in alignment and clinical outcomes between surgical cervical deformity (CD) patients with a subaxial upper-most instrumented vertebra (UIV) and patients with a UIV at C2. Use of CD-corrective instrumentation in the subaxial cervical spine is considered risky due to narrow subaxial pedicles and vertebral artery anatomy. While C2 fixation provides increased stability, the literature lacks guidelines indicating extension of CD-corrective fusion from the subaxial spine to C2. Methods: Included: operative CD patients with baseline (BL) and 1-year postop (1Y) radiographic data, cervical UIV ≥ C2. Patients were grouped by UIV: C2 or subaxial (C3-C7) and propensity score matched (PSM) for BL cSVA. Mean comparison tests assessed differences in BL and 1Y patient-related, radiographic, and surgical data between UIV groups, and BL-1Y changes in alignment and clinical outcomes. Results: Following PSM, 31 C2 UIV and 31 subaxial UIV patients undergoing CD-corrective surgery were included. Groups did not differ in BL comorbidity burden (P=0.175) or cSVA (P=0.401). C2 patients were older (64 vs. 58 yrs, P=0.010) and had longer fusions (9 vs. 6 levels, P=0.002). Overall, patients showed BL-1Y improvements in TS-CL (P<0.001), cSVA (P=0.005), McGS (P=0.004). Cervical flexibility was maintained at 1Y regardless of UIV, assessed by CL flexion (−0.2° vs. 6.0°, P=0.115) and extension (13.9° vs. 9.9°, P=0.366). While both subaxial and C2 patients showed BL-1Y improvements in McGS (both P<0.030), C2 patients improved to a larger degree (7.3° vs. 6.2°). Between UIV groups, there were no differences in BL-1Y changes in HRQLs, overall complication rates, or operative complication rates (all P>0.05). Conclusions: C2 UIV patients showed similar cervical range of motion and baseline to 1-year functional outcomes as patients with a subaxial UIV. C2 UIV patients also showed greater baseline to 1-year horizontal gaze improvement and had complication profiles similar to subaxial UIV patients, demonstrating the radiographic benefit and minimal functional loss associated with extending fusion constructs to C2. In the treatment of adult cervical deformities, extension of the reconstruction construct to the axis may allow for certain clinical benefits with less morbidity than previously acknowledged.

2414-469X

2414-4630

https://hdl.handle.net/10161/28198

AME Publishing Company

Journal of Spine Surgery

10.21037/jss.2019.06.04

Limited morbidity and possible radiographic benefit of C2 vs. subaxial cervical upper-most instrumented vertebrae

Journal article

Passias, Peter G|0000-0002-1479-4070|0000-0003-2635-2226

Shaffrey, Christopher I|0000-0001-9760-8386

236

244

2

Duke

School of Medicine

Clinical Science Departments

Orthopaedic Surgery

Neurosurgery

Published

5