Spine Journal - 2026-07-16 - Journal Article
The Impact of Social Deprivation Risk Factors on Rates of Short and Long-Term Postoperative Outcomes Following Single and Multi-Level Posterior Lumbar Instrumentation: A Propensity Score Matched Analysis.
Ashraf A, Lunasco L, Karnati J, Kaghazchi A, Ranganathan S, Jelkin G, Abid S, Moon E, Ashraf M, Wallace M, Cheng J, Adogwa O
Topics
Key Takeaway
Social deprivation risk factors increase 1-year pseudoarthrosis odds by 74% in single-level posterior lumbar instrumentation (OR 1.765) and 37% in 3–6 level constructs (OR 1.366), with long-term mechanical failure driven by social factors and short-term readmission driven by economic factors.
Summary Depth
Choose how much analysis to show on this article page.
Summary
This study used the TriNetX database to determine whether social deprivation risk factors (SDoH) affect pseudoarthrosis, mechanical failure, and healthcare utilization after posterior lumbar instrumentation across construct lengths. After propensity score matching for age, race, sex, comorbidities, and steroid use, SDoH-positive patients undergoing single-level fusion had 30-day readmission rates of 30.99% vs. 24.32% (OR 1.397) and 1-year pseudoarthrosis rates of 16.64% vs. 10.16% (OR 1.765). Subgroup analysis identified that economic risk factors primarily drove early readmission while social risk factors drove long-term mechanical complications, a distinction that persisted through 2 years in multi-level constructs.
Key Limitation
Reliance on administrative codes for both SDoH classification and outcome identification precludes verification of true pseudoarthrosis (CT-confirmed nonunion) and may conflate social deprivation proxies with unmeasured confounders such as smoking, nutrition, and medication adherence.
Original Abstract
BACKGROUND CONTEXT
Social determinants of health (SDoH) are well known risk factors that have been associated with poorer postoperative short-term outcomes following lumbar surgery. However, limited data exist on the long-term impact these risk factors have on lumbar surgery outcomes.
PURPOSE
To assess the impact of social deprivation risk factors on long-term mechanical complications, and short-term facility-based measures following either multi- or single-level posterior lumbar spinal instrumentation.
STUDY DESIGN
Retrospective study utilizing the TriNetX Research Network.
PATIENT SAMPLE
All patients underwent posterior lumbar instrumentation. From here, patients were divided into two groups: (1) those with social deprivation risk factors, and (2) those without social deprivation risk factors.
OUTCOME MEASURES
Primary outcomes, including pseudoarthrosis, mechanical failure, and composite mechanical complications at 1- and 2-years following index surgery. Secondary outcomes included hospital readmission, emergency room (ER) visit, reoperation, and composite medical complications at 30 and 90 days following surgery.
METHODS
The TriNetX Research Network was utilized to identify adult patients who underwent either single-level, 3-6 level, 7-12 level posterior spinal instrumentation for lumbar spinal stenosis or spondylolisthesis. These patients were then divided into 2 cohorts: those with and those without social deprivation risk factors, which were further categorized by social or economic risk factors. Propensity score matching was performed to adjust for age, race, gender, comorbidities, and chronic steroid use, thereby controlling for potential confounders. Postoperative outcomes were identified utilizing corresponding diagnostic and procedural codes.
RESULTS
A total of 76,955 patients met the inclusion criteria (Single-Level: N=33,933; 3-6 Level: N=36,279; 7-12 Level: N=6,743). Propensity score matching yielded 810 well-matched pairs for single-level (SLL), 1,056 pairs for 3-6 level (MLL), and 255 pairs for 7-12 level instrumentation. In SLL patients, SDoH(+) status significantly increased the odds of 30-day readmission (30.99% vs. 24.32%, OR 1.397, 95% CI [1.122-1.739]), a risk primarily driven by Economic factors (OR 1.932, 95% CI [1.347-2.772]). Long-term SLL mechanical complications were specifically driven by social factors, including 1-year pseudoarthrosis (16.64% vs. 10.16%, OR 1.765, 95% CI [1.244-2.504]) and composite mechanical complications (17.69% vs. 11.91%, OR 1.590, 95% CI [1.140-2.216]). In 3-6 level MLL patients, SDoH(+) status significantly increased both short-term utilization and long-term failure rates. These patients demonstrated significantly higher odds of 30-day readmission (37.03% vs. 29.92%, OR 1.377, 95% CI [1.148-1.651]), 1-year pseudoarthrosis (18.56% vs. 14.30%, OR 1.366, 95% CI [1.083-1.722]), and 1-year composite mechanical complications (21.78% vs. 16.86%, OR 1.373, 95% CI [1.105-1.707]). By 2 years, MLL risks remained elevated for pseudoarthrosis (OR 1.386, 95% CI [1.111-1.727]) and composite mechanical complications (OR 1.380, 95% CI [1.123-1.695]).
CONCLUSION
This large-scale propensity-matched analysis brings nuance to the conversation on the impact that social deprivation may have on surgical outcomes. Here it is demonstrated that patients with social deprivation risk factors undergoing single-level or 3-6 level posterior instrumentation demonstrated increased risk of both short- and long-term postoperative complications when compared to the general population. However, subgroup analysis revealed long-term complications, such as pseudoarthrosis and mechanical failure, were primarily driven by social risk factors, whereas short-term complications, such as hospital readmission and emergency department utilization, were predominantly driven by economic risk factors.