Spine - 2026-03-15 - Journal Article
Prevalence and Prognosis of Coronal Malalignment Following Lateral Lumbar Interbody Fusion for Minimally Invasive Treatment of Adult Spinal Deformity.
Chan AK, Sampath SG, Mummaneni PV, Park P, Uribe JS, Turner JD, Le VP, Eastlack RK, Fessler RG, Than KD, Fu KM, Wang MY, Kanter AS, Okonkwo DO, Nunley PD, Anand N, Mundis GM, Passias PG, Bess S, Shaffrey CI, Chou D, International Spine Study Group
Topics
Key Takeaway
Among preoperatively coronally aligned (Qiu type A) ASD patients undergoing cMIS-LLIF, 27.9% develop postoperative coronal malalignment at 2 years, associated with worse SF-36 PCS (34.78 vs. 37.42) and SRS-22r function/activity (3.03 vs. 3.36) but no difference in reoperation or complication rates.
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Summary
This study examined the prevalence and functional consequences of postoperative coronal malalignment (CVA ≥30 mm) in Qiu type A ASD patients treated with cMIS-LLIF using a prospective multicenter database. Of 43 patients, 12 (27.9%) developed coronal malalignment at 2 years; malaligned patients were older (73.0 vs. 69.0 years), had lower BMI, and had greater 2-year SVA (54.08 vs. 19.00 mm). Malalignment was associated with inferior SF-36 PCS and SRS-22r function/activity scores after covariate adjustment, but complication and reoperation rates were equivalent between groups.
Key Limitation
The sample size of 43 patients with only 12 malalignment events is critically underpowered to detect clinically meaningful differences in complication and reoperation rates, making the 'no difference in complications' conclusion unreliable.
Original Abstract
STUDY DESIGN
Retrospective analysis of prospective multicenter adult spinal deformity (ASD) database.
OBJECTIVE
To determine the prevalence and prognosis of postoperative coronal malalignment following LLIF for ASD with Qiu type A coronal alignment.
SUMMARY OF BACKGROUND DATA
Qiu type A coronal alignment is defined as coronal vertical axis (CVA) <30 mm. There is concern that circumferential minimally invasive surgery (cMIS) with lateral lumbar interbody fusion (LLIF) is associated with postoperative coronal malalignment in ASD with preoperative Qiu type A patients.
MATERIALS AND METHODS
Qui type A patients undergoing cMIS with LLIF for ASD were included, with ASD defined with at least: maximum CC ≥20°, SVA >5 cm, PI-LL ≥10°, or PT >20°. Two-year (2Y) clinical outcomes were compared for type A with 2Y CVA ≥30 mm (MAL) versus <30 mm (ALIGN) and were adjusted for factors reaching P <0.05 on univariate comparisons (age, BMI, and ODI).
RESULTS
Forty-three patients met inclusion criteria, of which 12 (27.9%) developed coronal malalignment and 31 (72.1%) remained coronally aligned at 2Y. At baseline, MAL were older (73.0 vs. 69.0, P =0.045), had a lower BMI (26.09 vs. 29.45, P =0.045), and were less disabled (ODI: 42.83 vs . 51.69, P =0.02). Otherwise, the groups were well-matched for baseline characteristics. At 2Y, MAL had a greater 2Y SVA (mean: 54.08 vs. 19.00 mm, P =0.01). Clinically, MAL was associated with inferior 2Y SF-36 PCS (34.78 vs . 37.42, adj P =0.04) and 2Y SRS-22r function/activity domain (3.03 vs . 3.36, adj P =0.04), but otherwise similar in other patient-reported outcome metrics (adj P >0.05 for all). 2Y complications were similar between groups, including for reoperations and major and minor complications (adj P >0.05 for all).
CONCLUSIONS
In Qui type A patients undergoing cMIS with LLIF for ASD, 27.9% develop coronal malalignment, which was associated with worse SF-36 PCS and SRS-22r function/activity. Despite radiographic malalignment, malalignment was not associated with higher two-year complication rates including reoperations.