Lightning Podiums: Spinal Gumbo - 803A

Presented by: P. Passias

Author(s):

P. Passias(1), S. Horn(1), G. Poorman(1), C. Bortz(1), F. Segreto(1), N. Frangella(1), N. Stekas(1), V. Lafage(2)

(1) New York University Langone Orthopedic Hospital, Division of Spinal Surgery, New York, NY, United States
(2) Hospital for Special Surgery, Department of Orthopaedic Surgery, New York, NY, United States

Abstract

Introduction: Patient-specific rods that are designed based on a particular pre-operative plan are a recent advancement in the field to help achieve desired operative alignment goals. The impact of these specific rods on post-operative alignment has not been previously investigated. The aim of this study was to investigate the role of pre-operative planning and patient-specific rods on post-operative outcomes.

Methods: Retrospective review of multi-levels cervical surgery patients from a single surgeon from 2016-2017 for cervical spondylotic myelopathy CSM. Patients were grouped according to the use of pre-operative planning and patient-specific, pre-contoured rods (PLAN) or absence of such planning/rods (NON). Pre-operative and post-operative alignment were measured for all patients, including cervical sagittal vertical axis (cSVA), cervical lordosis (CL), T1 Slope minus CL (TS-CL), and cervical-thoracic pelvic angle (CTPA). Alignment differences and clinical outcomes between the two groups were assessed using independent and paired samples t-tests.

Results: 34 patients were identified (15 PLAN, 19 NON). Pre- and post-operative CTPA, CL, cSVA and TS were all similar between the two groups (all p>0.05), though pre-operative TS-CL was slightly higher in the PLAN patients (28.13º versus 18.42º, p=0.049). There were no improvement differences pre- to post-operative for CTPA, CL, cSVA and TS between the groups (p>0.05). However, PLAN patients experienced a greater correction of TS-CL, with an average of 5.8º decrease versus a 3.5º increase in TS-CL for NON patients from pre- to post-operative (p=0.015). When looking at the two groups individually, PLAN patients did not experience a significant change from pre- to post-operative alignment for cSVA or TS-CL (cSVA: 27.5mm to 31.1mm, p=0.255; TS-CL: 28.1º to 22.3º, p=0.13), though their TS-CL did trend towards a significant post-operative improvement. In contrast, NON patients significantly worsened in cSVA and TS-CL post-operatively (cSVA: 21.8mm to 30.3mm, p< 0.001; TS-CL: 18.4º to 22.0º, p=0.035).

Conclusions: Multi-segment posterior decompression and fusion patients worsen in post-operative alignment without pre-operative planning. In addition, patients with pre-contoured rods and pre-operative planning experienced a greater correction of TS-CL after surgery than un-planned cases, though this is limited by the pre-operative difference in cervical-thoracic mismatch between planned and unplanned cases. Future studies are warranted to investigate these differences further with more power.