Work

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

Year: 2026

Type: article

Abstract: 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. 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. 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. 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. 1. We propose a five-level grading system for posterior cage migration, that shows preliminary potential for clinical application. 2. Owing to the anatomical characteristics of the lumbar vertebrae, significant displacement (Grades IV-V) is commonly seen at the L5/S1 segment, while it is rare in segments above L5. 3. The management of cage retropulsion should consider the time of displacement, involved segments, and degree of migration. Symptomatic cage retropulsion should be treated as soon as possible. Anterior surgery is suitable for segments above L5 with a lower degree of migration, whereas posterior surgery is appropriate for the L5/S1 segment with a more severe degree of migration. ALIF is also a reasonable alternative for carefully selected L5/S1 case with low-grade retropulsion when performed by experienced surgeons. 4. It is very necessary to completely remove the displaced cage.

Source: BMC Musculoskeletal Disorders

DOI: 10.1186/s12891-026-09616-0

Authors: Weiming Zhao, Shuxin Zheng, Yawen Su, Xi Yang, Chunguang Zhou, Yueming Song

Institutions: Sichuan University, West China Hospital of Sichuan University, West China Medical Center of Sichuan University

Language: English

Topic: Spine and Intervertebral Disc Pathology

Subfield: Pathology and Forensic Medicine

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $3,090