Expandable-First, PEEK-Second Hybrid Dual-Cage Technique for Unilateral Biportal Endoscopic Transforaminal Lumbar Interbody Fusion: A Technical Note With Illustrative Cases

To introduce a novel expandable-first, polyetheretherketone (PEEK)-second hybrid dual-cage technique, termed the “Lifting-Jack” technique, for unilateral biportal endoscopic transforaminal lumbar interbody fusion (UBE-TLIF) and to evaluate its early clinical and radiographic outcomes. This technical note and illustrative case series included 3 patients with single-level L4–5 degenerative spondylolisthesis who underwent UBE-TLIF using the Lifting-Jack technique. In this procedure, an expandable cage is first used as a controlled distractor, followed by insertion of a contralateral PEEK cage. Partial recompression is then performed to optimize cage-endplate conformity and load sharing. Clinical outcomes, including visual analogue scale (VAS) and Oswestry Disability Index (ODI) scores, were assessed preoperatively and up to 12 weeks postoperatively. Radiographic parameters, including anterior disc height, posterior disc height, segmental lordosis, and foraminal height, were also analyzed. All 3 patients showed rapid and sustained improvements in pain and function, with near-complete resolution of pain and marked improvement in disability by 12 weeks. Radiographic assessment showed consistent restoration of disc height, improved segmental lordosis, and increased foraminal height. No cage subsidence, cage migration, or perioperative complications were observed. The Lifting-Jack technique is a novel hybrid dual-cage strategy for UBE-TLIF that enables controlled disc-space distraction and facilitates safe PEEK cage insertion, with promising early clinical and radiographic outcomes. However, larger studies with longer follow-up are needed to confirm its safety, reproducibility, and durability.