Use of the kickstand rod improves coronal alignment and maintains correction compared to control at 2 year follow-up

Fthimnir M Hassan; Anson Bautista; Justin L Reyes; Varun Puvanesarajah; Josephine R Coury; Sarthak Mohanty; Joseph M Lombardi; Zeeshan M Sardar; Ronald A Lehman; Lawrence G Lenke

doi:10.1007/s43390-024-00950-8

Use of the kickstand rod improves coronal alignment and maintains correction compared to control at 2 year follow-up

Spine Deform. 2024 Aug 20. doi: 10.1007/s43390-024-00950-8. Online ahead of print.

Authors

Fthimnir M Hassan¹, Anson Bautista², Justin L Reyes³, Varun Puvanesarajah⁴, Josephine R Coury^{3

5}, Sarthak Mohanty⁶, Joseph M Lombardi^{3

5}, Zeeshan M Sardar^{3

5}, Ronald A Lehman^{3

5}, Lawrence G Lenke^{3

5}

Affiliations

¹ Department of Orthopaedic Surgery, The Och Spine Hospital/Columbia University Irving Medical Center, New York, NY, USA. fh2444@cumc.columbia.edu.
² Department of Orthopaedic Surgery, Dwight D. Eisenhower VA Medical Center, Leavenworth, KS, USA.
³ Department of Orthopaedic Surgery, The Och Spine Hospital/Columbia University Irving Medical Center, New York, NY, USA.
⁴ Department of Orthopaedics and Physical Performance, University of Rochester Medical Center, Rochester, NY, USA.
⁵ The Och Spine Hospital, New York Presbyterian, Columbia University Medical Center, 5141 Broadway, New York, NY, 10034, USA.
⁶ Department of Orthopaedic Surgery, Massachusetts General Hospital, Boston, MA, USA.

PMID: 39162958
DOI: 10.1007/s43390-024-00950-8

Abstract

Purpose: To assess and compare coronal alignment correction at 2 year follow-up in adult spinal deformity (ASD) patients treated with and without the kickstand rod (KSR) construct.

Methods: ASD patients who underwent posterior spinal fusion at a single-center with a preoperative coronal vertical axis (CVA) ≥ 3 cm and a minimum of 2 year clinical and radiographic follow-up were identified. Patients were divided into two groups: those treated with a KSR and those who were not. Patients were propensity score-matched (PSM) controlling for preoperative CVA and instrumented levels to limit potential biases that my influence the magnitude of coronal correction.

Results: One hundred sixteen patients were identified (KSR = 42, Control = 74). There were no statistically significant differences in patient characteristics (p > 0.05). At baseline, the control group presented with a greater LS curve (29.0 ± 19.6 vs. 21.5 ± 10.8, p = 0.0191) while the KSR group presented with a greater CVA (6.3 ± 3.6 vs. 4.5 ± 1.8, p = 0.0036). After 40 PSM pairs were generated, there were no statistically significant differences in baseline patient and radiographic characteristics. Within the matched cohorts, the KSR group demonstrated greater CVA correction at 1 year (4.7 ± 2.4 cm vs. 2.9 ± 2.2 cm, p = 0.0012) and 2 year follow-up (4.7 ± 2.6 cm vs. 3.1 ± 2.6 cm, p = 0.0020) resulting in less coronal malalignment one (1.5 ± 1.3 cm vs. 2.4 ± 1.6 cm, p = 0.0056) and 2 year follow-up (1.6 ± 1.0 vs. 2.5 ± 1.5 cm, p = 0.0110). No statistically significant differences in PROMs, asymptomatic mechanical complications, reoperations for non-mechanical complications were observed at 2 year follow-up. However, the KSR group experienced a lesser rate of mechanical complications requiring reoperations (7.1% vs. 24.3%. OR = 0.15 [0.03-0.72], p = 0.0174).

Conclusions: Patients treated with a KSR had a greater amount of coronal realignment at the 2 year follow-up time period and reported less mechanical complications requiring reoperation. However, 2 year patient-reported outcomes were similar between the two groups.

Keywords: Adult spinal deformity; Coronal malalignment; Kickstand rod; Patient-reported outcomes; Postoperative outcomes.