Lateral Interbody Fusion at L4/5: Management of the Transitional Psoas

Document Type

Article

Abstract

OBJECTIVE: Managing retraction of the lumbar plexus is critical to safely perform lateral lumbar interbody fusion (LLIF) via the transpsoas approach. Occasionally, a transitional psoas is encountered at L4/5 and has been postulated to be a contraindication to transpsoas LLIF. A case series of patients with transitional psoas who underwent L4/5 LLIFs is presented. METHODS: This retrospective review assessed 79 consecutive patients who underwent L4/5 LLIF during a 24-month period. Preoperative imaging was reviewed, and patients were classified into 2 groups: normal psoas or transitional psoas. Intraoperative features and outcomes were compared between groups. RESULTS: Seventy-nine patients underwent L4/5 LLIFs, of whom 23 had transitional psoas anatomy and 56 had normal psoas anatomy. Among patients with transitional psoas, the center of the psoas was a mean (range) of 11.2 (5.2-26.6) mm in front of the center of the vertebral body compared with 2.0 (0-4) mm in the normal psoas group. The mean (range) retraction time was similar between groups (10.8 [6.7-14.9] minutes in the transitional psoas group vs. 11.0 [7.8-15.0] minutes in the normal psoas group). No permanent motor injuries occurred in either group, and no differences in length of stay or preoperative or postoperative Oswestry Disability Index scores were found between the groups. The protocol for L4/5 LLIF in patients with transitional psoas anatomy is described. CONCLUSIONS: Transitional psoas anatomy is frequently encountered in surgical candidates for L4/5 LLIF. Through careful identification of the lumbar plexus and judicious retraction, the transpsoas LLIF can safely be performed in these patients.

Medical Subject Headings

Aged; Aged, 80 and over; Disease Management; Female; Humans; Lumbar Vertebrae (diagnostic imaging, surgery); Lumbosacral Plexus (diagnostic imaging, surgery); Male; Middle Aged; Prospective Studies; Psoas Muscles (diagnostic imaging, surgery); Retrospective Studies; Spinal Diseases (diagnostic imaging, surgery); Spinal Fusion (methods)

Publication Date

4-1-2021

Publication Title

World neurosurgery

E-ISSN

1878-8769

Volume

148

First Page

e192

Last Page

e196

PubMed ID

33385599

Digital Object Identifier (DOI)

10.1016/j.wneu.2020.12.105

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