Anterior Placement of Cages in Posterior Lumbar Interbody Fusion for Obtaining Good Lumbar Lordosis Formation

Daisuke Inoue; Hideki Shigematsu; Hiroaki Matsumori; Yurito Ueda; Toshiya Morita; Sachiko Kawasaki; Yuma Suga; Masaki Ikejiri; Yasuhito Tanaka

doi:10.22603/ssrr.2023-0133

Anterior Placement of Cages in Posterior Lumbar Interbody Fusion for Obtaining Good Lumbar Lordosis Formation

Spine Surg Relat Res. 2023 Sep 4;8(1):51-57. doi: 10.22603/ssrr.2023-0133. eCollection 2024 Jan 27.

Authors

Daisuke Inoue¹, Hideki Shigematsu², Hiroaki Matsumori¹, Yurito Ueda¹, Toshiya Morita³, Sachiko Kawasaki², Yuma Suga², Masaki Ikejiri², Yasuhito Tanaka²

Affiliations

¹ Department of Orthopedic Surgery, Kashiba Asahigaoka Hospital, Kashiba, Japan.
² Department of Orthopedic Surgery, Nara Medical University Hospital, Kashihara, Japan.
³ Department of Orthopedic Surgery, Ishinkai Yao General Hospital, Yao, Japan.

Abstract

Introduction: Posterior lumbar interbody fusion (PLIF) is a common treatment for nerve root disease associated with lumbar foraminal stenosis or lumbar spondylolisthesis. At our institution, PLIF is usually performed with high-angle cages and posterior column osteotomy (PLIF with HAP). However, not all patients achieve sufficient segmental lumbar lordosis (SLL). This study determined whether the location of PLIF cages affect local lumbar lordosis formation.

Methods: A total of 59 patients who underwent L4/5 PLIF with HAP at our hospital, using the same titanium control cage model, were enrolled in this cohort study. The mean ratio of the distance from the posterior edge of the cage to the posterior wall of the vertebral body/vertebral length (RDCV) immediately after surgery was 16.5%. The patients were divided into two groups according to RDCV <16.5% (group P) and ≥16.5% (group G). The preoperative and 6-month postoperative slip rate (%slip), SLL, local disk angle (LDA), ratio of disk height/vertebral height (RDV), 6-month postoperative RDCV, ratio of cage length/vertebral length (RCVL), and ratio of posterior disk height/anterior disk height at the fixed level (RPA) were evaluated via simple lumbar spine X-ray. The preoperative and 6-month postoperative Japanese Orthopedic Association (JOA) and low back pain visual analog scale (VAS) scores were also evaluated.

Results: Groups G and P included 31 and 28 patients, respectively. The preoperative %slip, SLL, LDA, RDV, JOA score, and low back pain VAS score were not significantly different between the groups. In groups G and P, 6-month postoperative %slip, SLL, LDA, RDV, RDCV, RCVL, and RPA were 3.3% and 7.9%, 18.6° and 15.4°, 9.7° and 8.0°, 36.6% and 40.3%, 21.1% and 10.1%, 71.4% and 77.0%, and 56.1% and 67.7%, respectively. The 6-month postoperative SLL, LDA, RDV, RDCV, RCVL, and RPA significantly differed (p=0.03, 0.02, 0.02, <0.001, <0.001, and <0.001, respectively).

Conclusions: Anterior PLIF cage placement relative to the vertebral body is necessary for good SLL in PLIF.

Keywords: anterior cage placement; high-angle cage; lumbar lordosis; posterior lumbar interbody fusion.