Indirect decompression of the central lumbar spinal canal by means of simultaneous bilateral transforaminal lumbar interbody fusion for severe degenerative lumbar canal stenosis with 3 years minimum follow-up

Abstract

Study design: Given the drawbacks of direct decompression for LCS, indirect decompression techniques such as oblique lateral interbody fusion from anterior/lateral approaches are gaining popularity. However, anterior/lateral approaches to the spine have risks of their own.We performed a retrospective analysis of a prospective cohort of LCS patients surgically treated in our facility. Objectives: 1) Reduce the technical demands of indirect decompression for severe LCS;2) Establish a reliable and simple indirect decompression technique for severe and extreme stenosis. Methods: Sixty-eight spinal segments of 50 patients were operated for LCS with instability. Bilateral screw distractors were attached to pedicle screws and bilateral TLIF was performed. Laminae and ligamentum flavum were preserved. Forty-five segments with pre-op cross-sectional thecal sack area (CSA) below 100 mm2 on T2 axial MRI were sampled for this study. Results: Decompressed levels were L2/3 in 3 cases, L3/4 in 19 cases, L4/5 in 20 cases, L5/S in 3 cases.There were no complications and no reoperations. Mean CSA increase was 75.8 mm2 (166% increase, from 58.6 mm2 pre-op to 134.4 mm2 at follow-up, p < 0.001). Mean disk space height increase was 5 mm (p < 0.001). Mean lower extremity pain visual analog scale (VAS, 10 points) improvement was 4.9 (p < 0.001), mean lower extremity paresthesia VAS improvement was 3.8 (p < 0.001). Union rate was 96%.Minimum follow-up is 3 years post-op. Conclusion: Posterior approach indirect decompression by bilateral TLIF is safe, effective for treatment of lower extremity symptoms of severe and extreme LCS, not technically demanding, and has high fusion rate.

Keywords

• Lumbar spine
• Ligamentum flavum
• Degenerative spinal canal stenosis
• Indirect decompression
• Bilateral TLIF