The Significance of Extra-Cage Bridging Bone via Radiographic Lumbar Interbody Fusion Criterion

Abstract

Study Design: Prospective observational study. Objectives: We aimed to analysis the distributional patterns of the intra- and extra-cage bridging bone (InCBB and ExCBB) and the significance of ExCBB using suggested lumbar interbody fusion criterion. Methods: This study included the patients with planned single-level transforaminal lumbar interbody fusion. We divided bridging bone into InCBB (in void of right or left cage) and ExCBB (outside of cages; anterior, posterior, intermediate, right, or left) and graded bridging scores from 0 to 2 on postoperative 1-year computed tomography. The fusion was defined as at least having one or more graded 2 and the evaluation were conducted twice by 2 raters. Results: Sixty-five patients were enrolled. All values of intra- and inter-rater reliability in left InCBB, anterior, and posterior ExCBB showed good agreements (≥0.75). Both InCBBs showed similar mean bridging scores (Rt:1.43 vs Lt:1.48), and in ExCBBs, the anterior was the highest (1.43), followed by the posterior (1.14); the right and left were the lowest (0.49 and 0.52 respectively). In subjects determined as fusion (85.4%), complete bridging was observed more in ExCBB (88.8%) than in InCBB (69.9%). Conclusions: Given the higher bridging scores in both InCBBs and Ant. ExCBB, bone grafting is important promoting factor to increase the interbody bridging bone regardless of outside or in void of cages. Based on our suggested criterion, ExCBB has a greater proportion compared to InCBBs for determining the fusion and extra-cage bone grafting should be considered as important procedures for interbody fusion.

Biportal Endoscopic Transforaminal Lumbar Interbody Fusion Using Double Cages: Surgical Techniques and Treatment Outcomes

“…It also provides solid anterior support after successful fusion. 27 Cage subsidence is the most common complication following LIF. The incidence ranges from 15.9% to 70%, depending on the types of cages, surgical techniques, follow-up duration, and image evaluation tools.…”

Characteristics of interbody bone graft fusion after transforaminal lumbar interbody fusion according to intervertebral space division

“…Similarly, Choi ( 31 ) divided the intervertebral space into 9 areas in an average way of 3 × 3. However, they did not apply partition to evaluate the fusion situation, and such mechanical partition method could not accurately describe the fusion characteristics of each partition from CT. Lee ( 32 ) used two cages as a reference point to divide the intervertebral space into 7 regions to observe the characteristics of intervertebral fusion after TLIF, including between two cages, left side of left cage, right side of right cage, front of cage, back of cage and inner cage. However, since Lee's research objects were TLIF patients after implantation of two fusion devices, his results cannot represent the fusion characteristics after single-cage TLIF, which are more commonly used now.…”

Evaluation of the efficacy and safety of 3D printing porous titanium cage with non-window type versus window type in posterior lumbar interbody fusion: A prospective, randomized, multicenter trial study

“…-For the control intervention group, Cage bone bridging (CBB) scoring system (17), including intracage bone bridging (InCBB) score and extracage bone bridging (ExCBB) score were used.…”