Radiological Outcome of Lumbar Lordosis Restored following Extreme Lateral Interbody Fusion (XLIF) plus Pedicle Screw Insertion (PSI)
Authors: Rehman Saif U. R. 
Published: April 2016

Introduction

Radiological outcome of Lumbar Lordosis restored following Extreme Lateral Interbody Fusion (XLIF) plus Pedicle Screw Insertion (PSI). Improving sagittal alignment in the lumbosacral spine following fusion for degenerative spinal disease remains an important goal of surgery. Numerous surgical techniques have been promoted as improving lumbar lordosis, elevating the height of the disk, and facilitating the decompression of the neural elements. Interbody support techniques are frequently cited as a reliable method of maintaining or improving segmental sagittal profile. The historical use of structural autograft has recently been supplemented by the increasing popularity of synthetic cages. Numerous cage configurations are available. Wedge-shaped cages are generally preferred because studies have shown this geometric shape to have a significant impact on the improvement of lordosis. Anterior cages have been cited as the most reliable method to restore anterior lordosis and disk space height. Posteriorly placed wedged cages have been shown in a prospective randomized study to maintain but not improve segmental lordosis following a posterior lumbar interbody fusion combined with pedicle instrumentation. In his study we observed that XLIF cages increases disc height, opening neural foramen, indirectly opening spinal canal by stretching out retrobuldged posterior longitudinal ligament and restoring biomechanics by correcting lumbar lordosis

Material and Methods

This is a retrospective study to review all cases of degenerative disc disease of lumbar spine that underwent Extreme Lateral Interbody Fusion (XLIF) and Pedicle Screw Insertion (PSI) from 1st June 2009 to 31st May 2011. From June 2009 to May 2011, 17 patients (14 female, 3male) were included. The electronic patient record which includes preoperative and postoperative radiographic results were reviewed and abstracted into an electronic database. Data entered in Data Form then in Excel sheet, number of disc involved, type of surgery anterior instrumentation (Extreme lateral Interbody fusion XLIF), posterior instrumentation (pedicle screw fixation PSF), Posterolateral bone grafting, both Pre & immediate postsurgical Cobb angles and disc heights were measured.

Results

From June 2009 to May 2011, 17 patients (14 female, 3male) were included. The mean patient's age at surgery was 61.88years (range 47–80). The mean of Preop disc height was 8.54mm and the mean Post XLIF disc height was 13.01mm. The mean of Preop Global Lumbar Lordosis (Cobb Angle) was 30.72° (range 7.80°-54°.90°) as well as the mean of Post XLIF Global Lumbar Lordosis (Cobb Angle) was 29.48° (range 9.70°-59°). The number of disc involved was one in 12 cases, two in 2 cases and three in 3 cases. Sixteen cases were underwent Anterior and Posterior instrumentation except one patient who underwent stand alone XLIF cage. The Posterolateral bone grafting was done in four cases. Through using a McNemar-Bowker Test, there is a strong association between the Pre-Op Disc Height and the Post-XLIF Disc Height, P –value < 0.05. In addition, There is a strong association between the PRE-OP GLOBAL LUMBAR LORDOSIS (Cobb Angle) and the POST- XLIF GLOBAL LUMBAR LORDOSIS (Cobb Angle) P-value < 0.05.

Conclusion

XLIF cages increases disc height, opening neural foramen, indirectly opening spinal canal by stretching out retrobuldged posterior longitudinal ligament and restoring biomechanics by correcting lumbar lordosis