Static cage morphology in short-segment transforaminal lumbar interbody fusions is associated with alterations in foraminal height but not clinical outcomes

Comparing Outcomes of Banana-Shaped and Straight Cages in Transforaminal Lumbar Interbody Fusion for Lumbar Degenerative Diseases: A Systematic Review and Meta-Analysis

OBJECTIVE

This meta-analysis aims to refine the understanding of the optimal choice between different cage shapes in transforaminal lumbar interbody fusion (TLIF) by systematically comparing perioperative data, radiological outcomes, clinical results, and complications associated with banana-shaped and straight bullet cages.

METHODS

A meticulous literature search encompassing PubMed, Embase, Scopus, Web of Science, China Knowledge Network, and Wanfang Data was executed up to October 5, 2023. Inclusion criteria focused on studies comparing banana-shaped and straight bullet cages in TLIF. The quality of included studies was assessed using appropriate tools such as the Newcastle-Ottawa Scale (NOS) for nonrandomized studies. Rigorous evaluations were performed for radiographic outcomes, including disc height (DH), segmental lordosis (SL), lumbar lordosis (LL), subsidence, and fusion rates. Clinical outcomes were meticulously evaluated using visual analogue scale (VAS), Oswestry Disability Index (ODI), and complications.

RESULTS

The analysis incorporated 7 studies, involving 573 patients (297 with banana-shaped cages, 276 with straight cages), all with NOS ratings exceeding 5 stars. No statistically significant differences were observed in operative time, blood loss, or hospitalization between the 2 cage shapes. Banana-shaped cages exhibited greater changes in DH (p = 0.001), SL (p = 0.02), and LL (p = 0.01). Despite statistically higher changes in ODI for straight cages (26.33, p < 0.0001), the actual value remained similar to banana-shaped cages (26.15). Both cage types demonstrated similar efficacy in VAS, complication rates, subsidence, and fusion rates.

CONCLUSION

Although banana-shaped cages can excel in restoring DH, SL, and LL, straight bullet cages can provide comparable functional improvements, pain relief, and complication rates.

Risk Factors Involved in the Early and Medium-Term Poor Outcomes of Percutaneous Endoscopic Transforaminal Discectomy: A Single-Center Experience

Objective

To investigate the risk factors involved in the early and medium-term poor outcomes of percutaneous endoscopic transforaminal discectomy (PETD) treatment of lumbar disc herniation (LDH) at the L4-5 level.

Methods

Between January 2015 and May 2020, we recruited 148 LDH patients at the L4-5 level who underwent PETD surgery. The patients were divided into Groups A and B, according to the surgical outcomes. Good and excellent outcomes were categorized into Group A, and generally good and poor outcomes were categorized into Group B. Clinical parameters (age, gender, symptom duration, hospital stay, operation time, blood loss, straight-leg raising (SLR), visual analog scale (VAS), Oswestry Disability Index (ODI) score and modified MacNab criteria) and radiologic parameters (foraminal height (FH), intervertebral height index (IHI), intervertebral angle (IVA), sagittal range of motion (sROM), and lumbar lordosis (LL)) were collected and analyzed using univariate and multiple logistic regression analyses.

Results

At the 6-month follow-up post operation, univariate analysis revealed that the symptom duration, SLR, IHI, and sROM were strongly associated with poor outcomes. However, multiple logistic regression analysis demonstrated that prolonged symptom duration, large SLR angel, and large sROM were independent risk factors for poor outcomes. At the 2-year follow-up post operation, univariate analysis suggested that advanced age, prolonged symptom duration, large preoperative VAS score, small FH, small IHI, and large sROM were potential risk factors for poor outcomes. However, multiple logistic regression analysis demonstrated that prolonged symptom duration, small IHI, and large sROM were independent risk factors for poor outcomes.

Conclusion

Our study demonstrated that prolonged symptom duration, large SLR angel, and large sROM were independent risk factors for poor outcomes immediately following PETD at the L4-5 level. However, prolonged symptom duration, small IHI, and large sROM were independent risk factors for poor outcomes at medium-term post PETD at the L4-5 level.