# Muscle damage in oblique lumbar interbody fusion and unilateral biportal endoscopic-transforaminal lumbar interbody fusion for single-level lumbar degeneration diseases: retrospective cohort study

## TL;DR

This study compares muscle damage from two types of lumbar fusion surgeries, finding that one causes less muscle damage and is safer for patients.

## Contribution

The study provides a direct comparison of muscle damage between OLIF and UBE-TLIF surgeries using cross-sectional muscle area measurements.

## Key findings

- OLIF resulted in significantly less blood loss, shorter operation time, and lower creatine kinase levels compared to UBE-TLIF.
- OLIF caused less damage to paraspinal muscles but more damage to psoas muscles compared to UBE-TLIF.
- The incidence of complications was similar between the two surgical approaches.

## Abstract

Iatrogenic injury and approach-related complications in lumbar fusion surgery have become significant concerns. This study aims to assess the muscle damage with oblique lumbar interbody fusion (OLIF) compared with unilateral biportal endoscopic-transforaminal lumbar interbody fusion (UBE-TLIF). This assessment will guide better clinical surgical choice in lumbar degeneration diseases.

This was a retrospective study comparing OLIF combined with anterolateral single screw–rod fixation and UBE-TLIF combined with percutaneous pedicle screws under navigation from January 2021 to December 2023. Individuals with single-level degenerative lumbar disease participated in the study. This study compared the baseline and perioperative parameters (blood loss, operation time, and haematological indicators) and clinical outcome (visual analogue scale scores, Japanese Orthopaedic Association scores, fusion rate, and complications). Measurements of the total cross-sectional area of psoas muscles and paraspinal muscles were obtained using regions of interest defined by manual tracing.

The cohort comprised 192 patients: 112 underwent OLIF (64 female; mean age 65.1 years) and 80 underwent UBE-TLIF (44 female; mean age 64 years). The operation time (P < 0.001), blood loss (P  < 0.001), and creatine kinase (P  < 0.001) were significantly lower in the OLIF group than in the UBE-TLIF group. The visual analogue scale score of the back was lower in the OLIF group than in the UBE-TLIF group (P  < 0.001), whereas the visual analogue scale score of the leg was higher in the OLIF group than in the UBE-TLIF group (P  < 0.001). The changes in the total cross-sectional area in the psoas muscles were significantly higher in the OLIF group than in the UBE-TLIF group (P  < 0.001). The changes in the total cross-sectional area in the paraspinal muscles were significantly lower in the OLIF group than in the UBE-TLIF group (P  < 0.001). There were significant differences in the fatty infiltration of the paraspinal muscles between the two groups (P  < 0.001). The incidence of complications was comparable between the two groups (P = 0.874).

With OLIF there were lower creatine kinase levels, less blood loss, and less damage to paraspinal muscles. Therefore, in cases where both procedures are equally appropriate, OLIF is safer and less damaging to muscles and is the first choice for patients.

Iatrogenic injury to the paraspinal muscles, disruption of the posterior tension band, and approach-related complications in lumbar fusion surgery have become significant concerns. The rapid advancement of endoscopic techniques over the past few decades has facilitated the application of spinal endoscopic methods to lumbar intervertebral fusion surgery. Oblique lumbar interbody fusion is becoming increasingly popular among spinal surgeons because of its minimally invasive nature.