Research

The Cantilever-Transforaminal Lumbar Interbody Fusion (c-TLIF) differs from other transforaminal techniques of lumbar interbody fusion by placing structural allograft in the anterior column and autologous bone in the middle column. It achieves circumferential fusion with no need for iliac crest bone graft, nerve or dural retraction, posterolateral dissection for transverse process fusion or the anterior approach. This study prospectively evaluated 26 consecutive patients with minimum of two-year follow-up.

Eighteen patients (69%) had one-level fusions; 8 patients had a two-level procedure, for a total of 34 levels. Eight of the patients had spondylolisthesis as the primary diagnosis, while the remaining were primarily degenerative disc disease. Solid fusion was achieved in 96% of the patients. The one case with known pseudoarthrosis was revised with an anterior procedure and subsequently achieved solid fusion. Revision surgery was required in two additional patients: one for graft extrusion into the foramen and the other for inadequate decompression. No other cases of postoperative radiculopathy existed. No dural lacerations occurred. The graft placement at 2-years was considered midline in 94% of the patients, with two grafts slightly towards the annulotomy. No instrumentation failures or complications were encountered. Lordosis was maintained or increased (average change 1.7 degrees per level; p=0.031). Patient functionality was improved from pre-operative to follow-up as measured by the Roland-Morris (average 6 pt change, p=0.004). Statistically significant improvements from prior to surgery were also noted in physical functionality, physical role, pain, vitality and social function, as measured by the subscales of the SF-36 (p<0.05 for each). Seventy-seven percent were satisfied with surgical treatment and would have the surgery again.

Conclusion: The cantilever-TLIF procedure allows circumferential lumbar fusion without the need for iliac crest bone graft, posterolateral fusion, anterior abdominal exposure or nerve and dural retraction. The interbody local autologous bone graft is under a compressive load due to the cantilever principle, which also has the able to maintain or restore lordosis. No patients had pseudarthrosis and outcome instruments demonstrate high patient satisfaction (77%) and statistically significant improvements in parameters of physical and social function.