Introduction: This study aims to compare clinical and radiological outcomes between lumbar arthrodesis with an interbody cage vs. bone graft in patients with degenerative spine disease. The role of interbodies in lumbar arthrodesis has been insufficiently supported by evidence, impacting clinical decision-making and, occasionally, insurance coverage.
Methods: A systematic review of the literature was performed to identify studies directly comparing outcomes of lumbar interbody arthrodesis between cage vs. bone. Twenty studies with 1508 patients (769 cage, 739 bone) were included. Clinical and radiological outcomes were the primary outcomes of interest. Intraoperative and post-operative complications were also included.
Results: We found that there was a significantly greater reduction of perceived back pain (VAS) in the cage group (p=0.03). Additionally, we found that there was a significantly greater increase in disc height among the cage group (p < 0.01). Fusion rates were 10% higher in the cage group but did not reach statistical significance. Estimated blood loss, operative time, ODI, leg pain (VAS), reoperation rates, change in segmental lordosis, or change in overall lordosis did not differ between the cage and non-cage implants. There was no difference regarding incidental durotomy rates, pseudoarthrosis, or surgical site infections between the two groups.
Conclusion : Our results suggest that cage implantation leads to greater maintenance of disc height and greater improvement of back pain (VAS). This study underlines the clinical value of interbody cages in lumbar arthrodesis for patients with degenerative spine disease.
