Bioabsorbable self-retaining PLA/nano-sized β-TCP cervical spine interbody fusion cage in goat models: an in vivo study

Abstract

Study design This is an experimental animal study. Objective The objective of this study was to compare an anterior cervical discectomy and interbody fusion of a novel polylactide/nano-sized β-tricalcium phosphate (PLA/nβ-TCP) bioabsorbable self-retaining cervical fusion cage (BCFC) with an autologous bone graft and polyetheretherketone (PEEK) cages. Background Although PLA cervical cages have potential advantages compared with traditional materials, they are not currently routinely used in spine surgery because of undesirable effects such as the lack of osteoconductivity and osteolysis around the implant. This study involved the manufacturing of a bioabsorbable cage from PLA/nβ-TCP that was then used as a device for anterior cervical discectomy and fusion (ACDF) on a goat cervical spine fusion model. Materials and methods Eighteen goats underwent C3/C4 discectomy and were randomly divided into three groups based on the following methods: Group A (n=6), an autologous bone graft; Group B (n=6), PEEK cage filled with an autologous graft; and Group C (n=6), BCFC filled with an autologous iliac bone. Radiography was performed preoperatively and postoperatively and at 1, 4, 8, and 12 weeks after the operation. Disc space height (DSH) was measured at the same time. After 12 weeks, the fused segments were harvested and evaluated with functional radiographic views, biomechanical testing, and histological analyses. Results Over a 12-week period, the BCFC and PEEK cage groups exhibited significantly higher DSH values than the bone graft group. Additionally, the BCFC group yielded a significantly lower range of motion in axial rotation than both the autologous bone graft and PEEK cage groups. A histologic evaluation revealed an increased intervertebral bone volume/total volume ratio and better interbody fusion in the BCFC group than in the other groups. Conclusion The BCFC device exhibited better results than the autologous bone graft and PEEK cages in single-level ACDF models in vivo. This device may be a potential alternative to the current PEEK cages.

Locking Stand-Alone Cage Constructs for the Treatment of Cervical Spine Degenerative Disease

“…APC might pose a substantial risk of hardware-related complications, such as plate dislodgement, soft tissue injury, tracheoesophageal lesions, and dysphagia [14,15]. Dysphagia is recognized as the earliest complaint after ACDF using an additional anterior plate.…”

“…Dysphagia is recognized as the earliest complaint after ACDF using an additional anterior plate. The reported incidence of transient dysphagia after ACDF ranges from 2%–71%, and that of chronic dysphagia ranges from 3%–21% [14,16-18]. Studies have found that LSC has a lower risk of dysphagia as a complication, compared with APC, in postoperative and follow-up periods [4].…”

“…During the process of bone remodeling, the settlement of the cage of <2 mm into the vertebral bodies until fusion is to be expected; subsidence is defined as the sinking of an object with a greater elasticity modulus (cage) into an object with a lower elasticity modulus (vertebral body) [1]. If the cage subsides into the vertebral body with disc space collapse, foraminal height and cervical alignment are not restored [8,14]. Subsidence has been reported in 9.3 to 62.5% of cervical segments analyzed, and it often occurs within 3 months after surgery [8,14,22-24].…”

“…If the cage subsides into the vertebral body with disc space collapse, foraminal height and cervical alignment are not restored [8,14]. Subsidence has been reported in 9.3 to 62.5% of cervical segments analyzed, and it often occurs within 3 months after surgery [8,14,22-24]. Although subsidence does not appear to affect clinical outcomes, this must be evaluated in long-term studies [7,25-27].…”

Integrated Design Approaches for 3D Printed Tissue Scaffolds: Review and Outlook

“…The reduced stiffness of the poly- l -lactic acid cages demonstrated enhanced interbody fusion compared to the titanium cages at six months. A tri-calcium phosphate cage, autologous bone graft, and polyether ether ketone cage were compared using an in vivo goat model and demonstrated that both cages outperformed the bone graft, with the tri-calcium phosphate device providing the greatest increase in intervertebral bone volume [117]. 3D printed titanium cages have also been tested in vivo and demonstrated good biocompatibility and osseointegration with similar performance to polyether ether ketone materials [30], thus demonstrating the potential in using 3D printing to reach new capabilities in spinal fusion treatments.…”