Preoperative Urinary N-Telopeptide is Associated with Rod Fracture after Corrective Adult Spinal Deformity Surgery

Thursday, June 1, 2023

8:30 AM – 6:15 PM

Location: Salons 7-8

Co-Author(s)

JD

Jerry Du, MD

Hospital for Special Surgery, United States

Co-Author(s)

FL

Francis Lovecchio, MD

Fellow
Hospital for Special Surgery, United States
GK

Gregory Kazarian, MD

Hospital for Special Surgery, United States
DK

David Kim, BS

Hospital for Special Surgery, United States
BZ

Bo Zhang, MD

United States

Presenting Author (Person doing the Podium Present(s)

RM

Robert Merrill, MD

Hospital for Special Surgery, United States

Co-Author(s)

JC

John Clohisy, MD

Hospital for Special Surgery, United States
AP

Anthony Pajak, BS

Hospital for Special Surgery, United States
AK

Austin Kaidi, MD

Hospital for Special Surgery, United States
RK

Rachel Knopp, MPH

Assistant Research Manager
Hospital for Special Surgery
New York, New York, United States
IA

Izzet Akosman, BS

Hospital for Special Surgery, United States
MJ

Michell Johnson, MD

Hospital for Special Surgery, United States
HN

Hiroyuki Nakarai

Hospital for Special Surgery, United States
AD

Alexander S. Dash

Medical Student
Icahn School of Medicine at Mount Sinai, United States
MC

Matthew Cunningham, MD, PHD

Attending Surgeon
Hospital for Special Surgery
New York, New York, United States
HK

Han Jo Kim, MD

Associate Professor
Hospital for Special Surgery
New York, NY, United States

Submitter(s)

FL

Francis Lovecchio, MD

Fellow
Hospital for Special Surgery, United States

Disclosure(s):

Robert Merrill, MD: No financial relationships to disclose

John Clohisy, MD: No financial relationships to disclose

Anthony Pajak, BS: No financial relationships to disclose

Hiroyuki Nakarai: No financial relationships to disclose

Introduction
Rod fracture following corrective surgery for ASD can result in in pain and loss of deformity correction. UNTX is an established marker of bone turnover. Low UNTX has been associated with pseudarthrosis in prior studies and may predict risk for rod fracture following corrective ASD surgery.

Aims/Objectives
The purpose of this study was to assess the association between preoperative Urinary N-telopeptide (UNTX) and rod fracture after corrective adult spinal deformity (ASD) surgery.

Methods
Adult patients who underwent ASD surgery by a single surgeon from 2015 to 2021 were identified. Corrective ASD surgery was identified based on radiographic criteria. Cases with ≥4 level fusions to the pelvis were included. All patients had at least 2 years of follow-up unless rod fracture occurred within 2 years of index surgery. UNTX was prospectively collected prior to index surgery. Potential patient demographic, comorbidity, surgical, complication, and radiographic confounders were analyzed. A multivariate model with UNTX stratified into ranges of 10 (i.e. value of 0-9=0, 10-19=1, 20-29=2) and potential confounders was created.

Results
A total of 155 patients were included in the study. There were 21 rod fractures (13.5%), of which 13 cases were revised (62%). On univariate analysis, the UNTX for rod fracture cases was 29.0±14.0, compared to 41.8±28.6 for non-rod fracture patients (p=0.002). There was no difference in UNTX based on primary (39.0±28.2) or revision fusions (41.9±26.2) (p=0.525). On analysis of potential confounders, the rod fracture cohort had more male patients, higher BMI, more diabetics, and higher incidence of high post-correction T1 pelvic angle (table 1). On multivariate analysis, lower preoperative UNTX was independently predictive of rod fracture (adjusted odds ratio 0.587, 95% confidence interval: 0.366-0.940, p=0.027).

Conclusions
Preoperative UNTX was lower in patients who developed rod fractures after corrective ASD surgery. These results suggest that UNTX can identify patients at risk for rod fracture and may guide intraoperative treatment strategies.