The pararectus approach is a complementary option for lower lumbar vertebral body replacement: Clinical feasibility and anatomical considerations.

Purpose
Lumbar vertebral body replacement (VBR) is indicated in unstable lumbar fractures with anterior column compromise but is technically demanding at the L4-L5 level due to high iliac crest position, large psoas muscle mass, and complex vascular anatomy. These factors may limit conventional lateral or direct anterior approaches. This study evaluated the feasibility, safety, anatomical characteristics, and radiographic outcomes of lumbar VBR performed via the pararectus approach.Methods
We performed a retrospective single-center cohort study of adult patients undergoing lumbar VBR at L4 or L5 using the pararectus approach between 2013 and 2024. Clinical data included operative time, blood loss, perioperative complications, neurological outcomes, and reoperations. Preoperative computed tomography and serial radiographs (postoperative, 6 weeks, and 12 months) were analyzed to characterize psoas muscle morphology, vascular anatomy, iliac crest height, and radiographic stability, including lumbar lordosis, segmental alignment, and adjacent disc height indices.Results
Seventeen patients (mean age 55 years) were included; indications were trauma in 8 patients (47%), deformity in 7 (41%), and tumor in 2 (12%). Mean isolated anterior operative time was 131 min and mean blood loss was 535 mL. No approach-related complications occurred, including neurovascular, urogenital, or peritoneal injuries. No new postoperative neurological deficits or ipsilateral hip flexor weakness were observed. One late revision for posterior rod failure occurred and was not attributable to the anterior approach. Anatomical analysis demonstrated large psoas cross-sectional areas, limited psoas-to-vessel distances, frequent high iliac crest overlap, and predominantly complex vascular configurations. Radiographic parameters, including lumbar lordosis, segmental sagittal and coronal alignment, and adjacent segment disc height indices, remained stable through 12 months, with no implant migration or cage protrusion.Conclusions
Lumbar VBR via the pararectus approach is feasible and safe in anatomically challenging cases, with low perioperative morbidity and maintenance of radiographic stability at mid-term follow-up. The pararectus approach represents a valuable complementary anterior option for lower lumbar VBR when conventional lateral or direct anterior techniques are limited.