title: [The design, preparation and compressive strength testing of interbody fusion cages made from a composite of multi-amino acid copolymer/tri-calcium phosphate].
abstract: This research was to design and prepare interbody fusion cages using composite materials of multi-amino acid copolymer/tri-calcium phosphate (MAACP/TCP) and to test compressive strength of the cages. 16 specimens of C3-4 segments from female adult goats were scanned by X-ray to exclude disease of cervical spine, and then anatomical data were measured, i. e. disc space height of C3-4 segment (DSH), sagittal diameter of C3 lower endplate (SDLE3), sagittal diameter of C4 upper endplate (SDUE4), coronary diameter of C3 lower endplate (CDLE3), and coronary diameter of C4 upper endplate (CDUE4). According to the anatomical data, we designed and prepared the interbody fusion cage using the composite of MAACP/TCP and titanium with the same sizes. The MAACP/TCP Cages were made with the method of injection molding and finish machining, and titanium Cages were made with machining. In the testing of compressive strength of Cages, the specimens were divided into three groups, tricortical iliac crest bone group (isolated from goats), MAACP/TCP Cage group and titanium Cage group. There were 8 specimens in every group with the same sizes, the length of 12 mm, the width of 10 mm, and the height of 6 mm. The compressive strength of all specimens was tested on a universal testing machine. The values of DSH, SDLE3, SDUE4, CDLE3 and CDUE4 were (4.78 +/- 0.17) mm, (15.06 +/- 0.53) mm, (12.46 +/- 0.44) mm, (14.47 +/- 0.51) mm and (12.15 +/- 0.65) mm, respectively. MAACP/TCP Cage was successfully designed and made with a compressive strength of 76.34 MPa, which was much higher than that of tricortical iliac crest bone (18.41 MPa). The maximal loading of universal testing machine was 50 000 N, so the compressive strength of titanium Cages, whose value should be more than 541.35 MPa, could not be tested precisely. It is feasible to make cages with MAACP/TCP composite, and the compressive strength of MAACP/TCP Cages was much higher than that of tricortical iliac crest bone isolated from goats.
authors.affiliation: Department of Orthopedics, West China Hospital, Sichuan Unversity, Chengdu 610041, China.
authors.forename: Chungnang
authors.initials: C
authors.lastname: Zhou
authors.forename: Yueming
authors.initials: Y
authors.lastname: Song
authors.forename: Chongqi
authors.initials: C
authors.lastname: Tu
authors.forename: Fuxing
authors.initials: F
authors.lastname: Pei
authors.forename: Hong
authors.initials: H
authors.lastname: Duan
authors.forename: Limin
authors.initials: L
authors.lastname: Liu
authors.forename: Hong
authors.initials: H
authors.lastname: Li
mesh_terms: D020341:Absorbable Implants; D000596:Amino Acids / Q000737:chemistry*; D000818:Animals; D001672:Biocompatible Materials / Q000138:chemical synthesis; D001696:Biomechanical Phenomena; D002130:Calcium Phosphates / Q000737:chemistry*; D002574:Cervical Vertebrae / Q000601:surgery*; D019245:Compressive Strength; D005260:Female; D006041:Goats; D008422:Materials Testing; D011108:Polymers / Q000737:chemistry*; D013123:Spinal Fusion / Q000295:instrumentation*
chemical_list: D000596:Amino Acids; D001672:Biocompatible Materials; D002130:Calcium Phosphates; D011108:Polymers; C018392:tricalcium phosphate