title: Biomechanical stability of a bioabsorbable self-retaining polylactic acid/nano-sized β-tricalcium phosphate cervical spine interbody fusion device in single-level anterior cervical discectomy and fusion sheep models.
abstract: OBJECTIVE
  The aim of this study was to investigate the biomechanical stability provided by a novel, polylactic acid/nano-sized, β-tricalcium phosphate, bioabsorbable, self-retaining cervical fusion cage (BCFC).
  
  
  METHODS
  Quasistatic nonconstraining torques (maximum 1.5 NM) induced flexion, extension, lateral bending (±1.5 NM), and axial rotation (±1.5 NM) on 32 sheep cervical spines (C2-C5). The motion segment C3-C4 was first tested intact; the following groups were tested after complete discectomy: autologous tricortical iliac crest bone graft, Medtronic-Wego polyetheretherketone (PEEK) cage, Solis PEEK cage, and BCFC. The autologous bone graft group was tested with an anterior plate. The mean range of motion (ROM) was calculated from the load-displacement curves.
  
  
  RESULTS
  BCFC significantly decreased ROM in lateral bending and axial rotation compared to other implants, and no significant difference in ROM between two types of PEEK cages and BCFC could be observed in flexion and extension. Anterior cervical plate (ACP) significantly decreased ROM in flexion and extension, but no significant difference in ROM between BCFC and bone graft plus ACP could be determined in lateral bending and axial rotation.
  
  
  CONCLUSIONS
  The BCFC device showed better stability to autologous tricortical iliac crest bone graft and PEEK cages in single-level anterior cervical discectomy and fusion models and thus may be a potential alternative to the current PEEK cages.
authors.affiliation: Department of Orthopedic Surgery, Zhongshan Hospital, State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Cao
authors.forename: Ping-Guo
authors.initials: PG
authors.lastname: Duan
authors.forename: Xi-Lei
authors.initials: XL
authors.lastname: Li
authors.forename: Feng-Lai
authors.initials: FL
authors.lastname: Yuan
authors.forename: Ming-Dong
authors.initials: MD
authors.lastname: Zhao
authors.forename: Wu
authors.initials: W
authors.lastname: Che
authors.forename: Hui-Ren
authors.initials: HR
authors.lastname: Wang
authors.forename: Jian
authors.initials: J
authors.lastname: Dong
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D001860:Bone Plates; D002130:Calcium Phosphates / Q000737:chemistry*; D002574:Cervical Vertebrae / Q000601:surgery*; D003131:Combined Modality Therapy; D017586:Diskectomy / Q000295:instrumentation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D007593:Joint Instability; D019344:Lactic Acid / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry*; D036103:Nanotechnology / Q000295:instrumentation; D011091:Polyesters; D011108:Polymers / Q000737:chemistry*; D012756:Sheep; D013123:Spinal Fusion / Q000295:instrumentation*; D016896:Treatment Outcome
chemical_list: D002130:Calcium Phosphates; D011091:Polyesters; D011108:Polymers; C485817:beta-tricalcium phosphate; D019344:Lactic Acid; C033616:poly(lactide)