title: The effect of anterior longitudinal ligament resection on lordosis correction during minimally invasive lateral lumbar interbody fusion: Biomechanical and radiographic feasibility of an integrated spacer/plate interbody reconstruction device.
abstract: BACKGROUND
  Lateral lumbar interbody fusion is powerful for correcting degenerative conditions, yet sagittal correction remains limited by anterior longitudinal ligament tethering. Although lordosis has been restored via ligament release, biomechanical consequences remain unknown. Investigators examined radiographic and biomechanical of ligament release for restoration of lumbar lordosis.
  
  
  METHODS
  Six fresh-frozen human cadaveric spines (L3-S1) were tested: (Miller et al., 1988) intact; (Battie et al., 1995) 8mm spacer with intact anterior longitudinal ligament; (Cho et al., 2013) 8mm spacer without intact ligament following ligament resection; (Galbusera et al., 2013) 13mm lateral lumbar interbody fusion; (Goldstein et al., 2001) integrated 13mm spacer. Focal lordosis and range of motion were assessed by applying pure moments in flexion-extension, lateral bending, and axial rotation.
  
  
  RESULTS
  Cadaveric radiographs showed significant improvement in lordosis correction following ligament resection (P<0.05). The 8mm spacer with ligament construct provided greatest stability relative to intact (P>0.05) but did little to restore lordosis. Ligament release significantly destabilized the spine relative to intact in all modes and 8mm with ligament in lateral bending and axial rotation (P<0.05). Integrated lateral lumbar interbody fusion following ligament resection did not significantly differ from intact or from 8mm with ligament in all testing modes (P>0.05).
  
  
  CONCLUSIONS
  Lordosis corrected by lateral lumbar interbody fusion can be improved by anterior longitudinal ligament resection, but significant construct instability and potential implant migration/dislodgment may result. This study shows that an added integrated lateral fixation system can significantly improve construct stability. Long-term multicenter studies are needed.
authors.affiliation: Spine Institute of San Diego, 6719 Alvarado Road, Suite 308, San Diego, CA 92120, USA. Electronic address: choll@siosd.com.
authors.forename: Choll
authors.initials: C
authors.lastname: Kim
authors.affiliation: Musculoskeletal Education and Research Center, Globus Medical, Inc., 2560 General Armistead Avenue, Audubon, PA 19403, USA. Electronic address: jharris@globusmedical.com.
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Harris
authors.affiliation: Musculoskeletal Education and Research Center, Globus Medical, Inc., 2560 General Armistead Avenue, Audubon, PA 19403, USA. Electronic address: amuzumdar@globusmedical.com.
authors.forename: Aditya
authors.initials: A
authors.lastname: Muzumdar
authors.affiliation: Musculoskeletal Education and Research Center, Globus Medical, Inc., 2560 General Armistead Avenue, Audubon, PA 19403, USA. Electronic address: skhalil@globusmedical.com.
authors.forename: Saif
authors.initials: S
authors.lastname: Khalil
authors.affiliation: Spine Institute of San Diego, 6719 Alvarado Road, Suite 308, San Diego, CA 92120, USA. Electronic address: sclafani@ucla.edu.
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Sclafani
authors.affiliation: Spine Institute of San Diego, 6719 Alvarado Road, Suite 308, San Diego, CA 92120, USA. Electronic address: Kam@siosd.com.
authors.forename: Kamshad
authors.initials: K
authors.lastname: Raiszadeh
authors.affiliation: Musculoskeletal Education and Research Center, Globus Medical, Inc., 2560 General Armistead Avenue, Audubon, PA 19403, USA. Electronic address: bbucklen@globusmedical.com.
authors.forename: Brandon S
authors.initials: BS
authors.lastname: Bucklen
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D001860:Bone Plates; D002102:Cadaver; D006801:Humans; D017846:Longitudinal Ligaments / Q000601:surgery*; D008141:Lordosis / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D008159:Lumbar Vertebrae / Q000503:physiopathology / Q000601:surgery*; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000295:instrumentation* / Q000379:methods*; D011859:Radiography; D016059:Range of Motion, Articular; D013123:Spinal Fusion / Q000295:instrumentation* / Q000379:methods*
keywords: Anterior longitudinal ligament release; Integrated lateral interbody device; Minimally invasive surgery; Spine biomechanics