Beta—tricalcium phosphate as a substitute for autograft in interbody fusion cages in the canine lumbar spine

Abstract

<jats:p content-type="fine-print"><jats:italic>Object.</jats:italic> An interbody fusion cage has been introduced for cervical anterior interbody fusion. Autogenetic bone is packed into the cage to increase the rate of union between adjacent vertebral bodies. Thus, donor site—related complications can still occur. In this study a synthetic ceramic, β—tricalcium phosphate (TCP), was examined as a substitute for autograft bone in a canine lumbar spine model.</jats:p> <jats:p content-type="fine-print"><jats:italic>Methods.</jats:italic> In 12 dogs L-1 to L-4 vertebrae were exposed via a posterolateral approach, and discectomy and placement of interbody fusion cages were performed at two intervertebral disc spaces. One cage was filled with autograft (Group A) and the other with TCP (Group B). The lumbar spine was excised at 16 weeks postsurgery, and biomechanical, microradiographic, and histological examinations were performed.</jats:p> <jats:p content-type="fine-print">Both the microradiographic and histological examinations revealed that fusion occurred in five (41.7%) of 12 operations performed in Group A and in six (50%) of 12 operations performed in Group B. The mean percentage of trabecular bone area in the cages was 54.6% in Group A and 53.8% in Group B. There were no significant intergroup differences in functional unit stiffness.</jats:p> <jats:p content-type="fine-print"><jats:italic>Conclusions.</jats:italic> Good histological and biomechanical results were obtained for TCP-filled interbody fusion cages. The results were comparable with those obtained using autograft-filled cages, suggesting that there is no need to harvest iliac bone or to use allo- or xenografts to increase the interlocking strength between the cage and vertebral bone to achieve anterior cervical interbody fusion.</jats:p>

Small‐animal models for testing macroporous ceramic bone substitutes

“…Different animal species have also been used to evaluate bone substitutes. For instance, in vivo studies have been conducted in rats, 10,15,20 rabbits, 8,16,[21][22][23][24][25] dogs, 13,26,27 sheep, 9 and goats. 28 As these animals are different in terms of their metabolisms and bone physiology, direct and strict comparison between all these studies is difficult.…”

&beta;-Tricalcium Phosphate Combined with Recombinant Human Bone Morphogenetic Protein-2: A Substitute for Autograft, Used for Packing Interbody Fusion Cages in the Canine Lumbar Spine

“…6. In our previous study, 16) the interbody fusion cages filled with -TCP demonstrated comparable efficacy to the cages with autogenous bone in the fusion rate of union between adjacent vertebral bodies. It has been reported that BMP can induce de novo bone formation in subcutaneous sites in the absence of marrow elements.…”

“…15) Some of them have been used clinically and have given acceptable surgical results. In our previous study, 16) synthetic beta-tricalcium phosphate (Ca 3 (PO 4 ) 2 ) (-TCP) was examined. It gave good outcomes as autogenous bone in the examinations of microradiographs and histological sections.…”

Anterior lumbar interbody fusion with carbon fiber cage loaded with bioceramics and platelet-rich plasma. An experimental study on pigs

“…However, β-TCP has seldom been used alone in anterior spinal fusion. Among the limited publications describing the use of β-TCP alone in anterior spinal fusion in animal studies, the results have varied [20,26]. In our previous study, β-TCP provided poorer bone formation in comparison with autograft in an anterior spinal fusion model (H. Li et al submitted for publication).…”