Assessing the Optimization of Alignment over Time in Circumferential Minimally-Invasive Adult Spinal Deformity Surgery: A Retrospective, Single-Center

Thursday, June 1, 2023

8:30 AM – 6:15 PM

Location: Salons 7-8

Co-Author(s)

PT

Peter S. Tretiakov, BS

United States
PD

Pooja R. Dave

Miami, Florida, United States
JM

Jamshaid M. Mir, MD

Research Fellow
NYU Langone Health | NY Spine Institute, United States
SO

Stephane Owusu-Sarpong, MD

Orthopedic Surgery Resident
NYU Langone Health, United States
OO

Oluwatobi Onafowokan

United Kingdom
MJ

M. Burhan Janjua

United States
TR

Timothy Roberts

Orthopaedic Spine Surgeon
Westbury, New York, United States
AM

Angel Macagno

United States
NP

Nicholas Post

United States
AD

Alexandre De Moura

United States

Presenting Author (Person doing the Podium Present(s)

PP

Peter G. Passias, M.D.

Spine Surgeon
NYU Langone Orthopedic Hospital
New York, New York, United States

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Submitter(s)

PP

Peter G. Passias, M.D.

Spine Surgeon
NYU Langone Orthopedic Hospital
New York, New York, United States

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Disclosure(s):

Peter G. Passias, MD: No relevant disclosure to display

Background: Circumferential minimally-invasive surgery (cMIS) techniques in ASD surgery continues to rise in popularity and usage due to the potential for minimization of peri-operative complications, physiologic burden of surgery, and catastrophic outcomes. The field continues to advance exponentially, yet there remains a paucity of literature assessing trends in optimization of radiographic alignment after MIS surgery.

Purpose: To determine trends in longitudinal outcomes for ASD patients receiving cMIS surgery over consecutive years, and

Methods: Operative ASD patients ≥18yrs undergoing cMIS surgery with complete pre-(BL) and up to 5-year(5Y) postop radiographic/HRQL data were assessed. Linear regression established correlative markers for temporal changes in demographic, radiographic, and patient-reported data. Patients were then stratified by achievement of optimal radiographic alignment by 2Y post-op, defined as >2 of the following: 1) meeting Lafage et al. age-alignment targets by 2Y, 2) achieving ideal PI-LL or SVA by 2Y per SRS-Schwab criteria 3) meeting GAP-Proportioned targets by 2Y, or 4) meeting sagittal age-adjusted score (SAAS) targets by 2Y. Means comparison analysis assessed differences in variables between Optimized (Opt) and Not-Optimized (nOpt) patients in patients stratified in halves by date of surgery (DOS). Backstep regression analysis assessed factors significantly associated with achievement of optimized outcomes.

Results: 144 ASD patients (62.85±13.93 years, 75.7% female, BMI: 29.23±6.64 kg/m2, CCI: 2.15±1.71) were included. Mean radiographic: parameters: C7-S1 SVA: 5.92 cm, PI-LL: 13.95°, S1PT: 22.55°. Linear regression revealed significant correlation by increasing date of surgery (DOS), and ΔPI-LL (p <.001), ΔLumbar Lordosis (LL) (p=.015), and ΔPT (p=.004). Furthermore, linear regression revealed positive correlations between date of surgery and optimization scores (p=.040). After ranking patients by DOS, 39.2% of patients in the Early group were considered optimized, compared to 55.8% of patients in the Late group. Optimized patients demonstrated significantly lower peri-operative complication rates (p=.012), neurological complication rates (p=.006), and had a fewer number of total complications by 2Y (p=.014). Rates of proximal junctional failure (PJF) were also noted to be significantly lower in the Late group (p=.041). Multivariate regression controlling for age, gender, and frailty per mASD-FI at baseline revealed that increased DOS was an independent predictor of achieving optimal radiographic alignment (p <.001).

Conclusions: Circumferential minimally invasive technique may diminishment the risk of complications in patients undergoing ASD surgery, yet data assessing radiographic alignment trends has been lacking. The present study demonstrates that circumferential MIS patients operated on more recently have improved likelihood of reaching alignment targets, and optimized patients are subsequently less likely to sustain peri- or post-operative complications by 5Y.