Revision surgical treatments and classification system for cage retropulsion in degenerative lumbar disease

Weiming Zhao; Shuxin Zheng; Yawen Su; Xi Yang; Chunguang Zhou; Yueming Song

doi:10.1186/s12891-026-09616-0

Revision surgical treatments and classification system for cage retropulsion in degenerative lumbar disease

BMC Musculoskelet Disord. 2026 Feb 16. doi: 10.1186/s12891-026-09616-0. Online ahead of print.

Authors

Weiming Zhao^#¹, Shuxin Zheng^#¹, Yawen Su¹, Xi Yang¹, Chunguang Zhou², Yueming Song¹

Affiliations

¹ Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital and West China School of Medicine, Sichuan University, Chengdu, 610041, P. R. China.
² Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital and West China School of Medicine, Sichuan University, Chengdu, 610041, P. R. China. 18113155950@163.com.

^# Contributed equally.

PMID: 41699569
DOI: 10.1186/s12891-026-09616-0

Abstract

Background: Cage retropulsion is a severe complication of lumbar spinal fusion, causing neurological deficits and spinal instability. Current evidence on revision strategies is limited by small sample sizes, with no consensus on surgical planning.

Methods: This retrospective study analyzed 14 patients (11 males, 3 females; mean age 57.2 ± 11.2 years) who underwent revision surgery for cage retropulsion (> 3 mm posterior displacement) after lumbar fusion between 2013 and 2023. A novel 5-grade classification system (I-V) based on migration severity was proposed. Surgical approaches (anterior, n = 5; posterior, n = 9) were selected by revision timing, segment, and migration grade. Outcomes were assessed via VAS, ODI, and imaging; operative time, blood loss, and complications were recorded.

Results: 85.7% (12/14) patients showed clinical improvement: VAS decreased from 7.3 ± 1.2 to 2.3 ± 1.1, ODI from 69.5 ± 12.4% to 15.2 ± 8.7%. The average operation time for anterior approach was 215.0 ± 44.5 min, and the average blood loss was 190.0 ± 156.2 ml. The average operation time for posterior approach was 281.9 ± 90.9 min, and the average blood loss was 387.5 ± 92.7 ml. 50% (7/14) had complications, mainly transient abdominal distension (n = 5). 85.7% (12/14) achieved fusion at 78.9-month follow-up.

Conclusion: This study proposes a practical classification system with preliminary feasibility in surgical approach selection for cage retropulsion. For symptomatic cases, early revision may yield better outcomes. Anterior surgery is recommended for L5-above segments with mild retropulsion, and posterior surgery is suggested for L5/S1 with severe retropulsion. In addition, anterior lumbar interbody fusion (ALIF) is a good option for L5/S1 with low-grade retropulsion when performed by experienced surgeon. Surgical success depends on tailored strategies considering revision timing, segments, and migration grade. But additional data are needed to confirm long-term safety and inform optimal management.

Keywords: Cage retropulsion; Lumbar interbody fusion; Migration grade; Revision surgery; Surgical approach.