Analysis of the Factors Affecting Lumbar Segmental Lordosis After Lateral Lumbar Interbody Fusion.

STUDY DESIGN Retrospective study. OBJECTIVE To elucidate factors that determine segmental lordosis after lateral retroperitoneal lumbar interbody fusion (LLIF) with percutaneous pedicle screw fixation. SUMMARY OF BACKGROUND DATA LLIF has been widely used in degenerative lumbar spine surgery. However, the detailed mechanisms that determine segmental lordosis are still unknown. METHODS A total of 69 patients who underwent LLIF with posterior pedicle screw fixation without posterior osteotomy were analyzed. Computed tomography was performed before and within 2 weeks after surgery, and segmental lordotic angle (SLA) after surgery (Post-SLA) was predicted using multiple regression analysis. Explanatory factors considered in this study included SLA before surgery (Pre-SLA), disc height before surgery (DiscH), cage position (CageP; distance between the center of the cage and the center of the disc, where a positive value indicates an anterior cage position), cage angle (CageA), cage height (CageH), CageH-DiscH (amount of lift up), previous decompression surgery, and level fused. RESULTS A total of 102 levels were analyzed. Multiple regression analysis revealed that the Post-SLA can be predicted with three independent variables, CageP, Pre-SLA, and CageH-DiscH and the adjusted R was 0.70. In cases when the cage was located anteriorly (CageP > 3 mm), Post-SLA was greater with larger CageH, larger CageA, and larger Pre-SLA. When the cage was located in the middle (3 mm ≤CageP ≤-1 mm), Post-SLA was greater with larger CageP, larger Pre-SLA, and without previous decompression surgery. If the cage was located posteriorly (CageP < -1 mm), Post-SLA was greater with smaller CageH-DiscH and greater Pre-SLA. CONCLUSION To gain maximum segmental lordosis in LLIF, the cage should be located anteriorly. Furthermore, if the cage can be located anteriorly, a thicker cage with proper angle cage will gain segmental lordosis. If the cage is located posteriorly, a thin cage should be selected. LEVEL OF EVIDENCE 3.

[1]  S. Matsuda,et al.  Sagittal imbalance treated with L5 pedicle subtraction osteotomy with short lumbar fusion from L4 to sacrum using four screws into L4 for enhanced fixation two additional vertebral screws: a technical note , 2018, European Spine Journal.

[2]  K. Sairyo,et al.  Complications Associated With Lateral Interbody Fusion: Nationwide Survey of 2998 Cases During the First 2 Years of Its Use in Japan , 2017, Spine.

[3]  K. Cho,et al.  Does Lordotic Angle of Cage Determine Lumbar Lordosis in Lumbar Interbody Fusion? , 2017, Spine.

[4]  N. Anand,et al.  The Influence of Lordotic cages on creating Sagittal Balance in the CMIS treatment of Adult Spinal Deformity , 2017, International Journal of Spine Surgery.

[5]  S. Matsuda,et al.  Effect of Indirect Neural Decompression Through Oblique Lateral Interbody Fusion for Degenerative Lumbar Disease , 2015, Spine.

[6]  K. Khajavi,et al.  Two-year radiographic and clinical outcomes of a minimally invasive, lateral, transpsoas approach for anterior lumbar interbody fusion in the treatment of adult degenerative scoliosis , 2014, European Spine Journal.

[7]  Kevin Gill,et al.  Aging changes in lumbar discs and vertebrae and their interaction: a 15-year follow-up study. , 2014, The spine journal : official journal of the North American Spine Society.

[8]  P. Roussouly,et al.  Compensatory mechanisms contributing to keep the sagittal balance of the spine , 2013, European Spine Journal.

[9]  Alexander W. L. Turner,et al.  Lordosis restoration after anterior longitudinal ligament release and placement of lateral hyperlordotic interbody cages during the minimally invasive lateral transpsoas approach: a radiographic study in cadavers. , 2012, Journal of neurosurgery. Spine.

[10]  A. Sama,et al.  Factors Influencing Segmental Lumbar Lordosis After Lateral Transpsoas Interbody Fusion , 2012, Orthopaedic surgery.

[11]  Adam S. Kanter,et al.  Complications and radiographic correction in adult scoliosis following combined transpsoas extreme lateral interbody fusion and posterior pedicle screw instrumentation. , 2010, Neurosurgical focus.

[12]  N. Anand,et al.  Minimally Invasive Multilevel Percutaneous Correction and Fusion for Adult Lumbar Degenerative Scoliosis: A Technique and Feasibility Study , 2008, Journal of spinal disorders & techniques.

[13]  K. Bridwell.  Decision Making Regarding Smith-Petersen vs. Pedicle Subtraction Osteotomy vs. Vertebral Column Resection for Spinal Deformity , 2006, Spine.

[14]  H. Aryan,et al.  Extreme Lateral Interbody Fusion (XLIF): a novel surgical technique for anterior lumbar interbody fusion. , 2006, The spine journal : official journal of the North American Spine Society.

[15]  L. Lenke,et al.  Comparison of Smith-Petersen Versus Pedicle Subtraction Osteotomy for the Correction of Fixed Sagittal Imbalance , 2005, Spine.

[16]  William Horton,et al.  The Impact of Positive Sagittal Balance in Adult Spinal Deformity , 2005, Spine.

[17]  L. Lenke,et al.  Pedicle subtraction osteotomy for the treatment of fixed sagittal imbalance. Surgical technique. , 2004, The Journal of bone and joint surgery. American volume.

[18]  L. Lenke,et al.  Pedicle Subtraction Osteotomy for the Treatment of Fixed Sagittal Imbalance , 2003, The Journal of bone and joint surgery. American volume.

[19]  J. Buchowski,et al.  Functional outcome and radiographic correction after spinal osteotomy. , 2002, Spine.

[20]  L. Lenke,et al.  Complications and predictive factors for the successful treatment of flatback deformity (fixed sagittal imbalance). , 1999, Spine.