J Minim Invasive Spine Surg Tech.  2021 Oct;6(2):90-97. 10.21182/jmisst.2021.00157.

MRI Study to Evaluate Anatomic Oblique Lumbar Interbody Fusion Corridor in Indian Population

• Gajjar S
• Jhala A
• Kiri S
• Mistry M

• KMID: 2562089
• DOI: http://doi.org/10.21182/jmisst.2021.00157

Abstract

Objective
The anatomic corridor is defined by different studies in the western population but the exact corridor for the Indian population is never been studied. Objective of the study was to define anatomical corridor for preoperative assessment of Oblique Lumbar Interbody Fusion (OLIF) in the Indian population.
Methods
We selected imaging data from 180 adults (90 males and 90 females) who underwent MRI. The windows studied at L1-2 to L4-5 levels were vascular window, bare window, psoas major window, and operative window. The bare window was further analysed by dividing it into three groups. Group 1 with no window, group 2 with 0 to 5 mm window, and group 3 with more than 5 mm. Statistical analysis was carried out by unpaired t-test.
Results
The bare window was largest at L1-2 (1.29 ± 0.53 cm) and smallest at L4-5 (0.79 ± 0.52 cm). The psoas major window was largest at L3-4 (1.24±0.38 cm) and smallest at L1-2 (0.45±0.47 cm). The operative window was largest at L3-4 (2.4±0.47 cm) and smallest at L4-5 (1.72 ± 0.67 cm). In 10.56% of patients at L4-5, there was no bare window and OLIF cannot be performed in these patients.
Conclusion
Bare window gradually decreases from L12 to L45 levels. In the majority of patients at L12, L23, and L34 there is adequate bare window and OLIF can be safely performed. In 10.56% of patients, the bare window for performing OLIF does not exist at L45 and OLIF may not be feasible in these patients.

Keyword

Oblique lumbar interbody fusion; Oblique corridor; Bare window; Anatomical corridor