A new concept for implant fixation: bone-to-bone biologic fixation

Abstract

Many attempts have been made to reduce complications of bone implant, such as pedicle screw loosening. To address this problem, the authors suggest a new concept of boneto-bone biologic fixation using recombinant human bone morphogenetic protein-2 (rhBMP-2)-loaded cannulated pedicle screws. Recombinant human bone morphogenetic protein-2 is an osteoinductive cytokine. Four types of titanium pedicle screws were tested (uncannulated, cannulated with no loading, beta-tricalcium phosphate (TCP)-loaded, and TCP/BMP2 loaded) using 16 miniature pigs. Radiological evaluation was conducted to assess the fusion and loosening of pedicle screws. Twelve weeks after implantation, peak torsional extraction torque was measured, and the pedicle screw and bone interface was evaluated by micro-computed tomography (µCT) and histologic examination. The mean value of the radiological score was significantly greater in the TCP/BMP2 loaded group at 12 weeks post-operation compared to those in the other groups. CT images showed distinct bone formation surrounding TCP/BMP2 loaded cannulated pedicle screws compared to the other groups. Mean extraction torsional peak torque at 12 weeks postoperative was more than 10-fold higher in the TCP/BMP2 loaded pedicle screw group than in the other groups. Bone surface and bone volume, as quantitated through µCT, were higher in the TCP/BMP2 loaded group. Histologic examination revealed bone-to-bone fixation at the interface of pedicle screws and pre-existing bone. Bone-to-bone biologic fixation through the holes of TCP/BMP2 loaded pedicle screws significantly increased fixation strength and represents a novel method that can be applied to osteoporotic or tumour spine surgeries.

Exploring the mechanism behind improved osteointegration of phosphorylated titanium implants with hierarchically structured topography

“…we designed a novel biomimetic micro/nano-structured surface with surface roughness value exactly in this scale. Many reports have also manifested that the gradient biomimetic morphology would be beneficial in promoting cell adhesion, especially initial adhesion [57][58][59]. Beyond that, on the surfaces with nano-scale surface roughness, it is reported that osteoblasts had more available adhesion sites, proliferated and interacted more, which eventually resulted in positive effect on osteogenesis [60][61][62][63].…”

Bone morphogenetic protein effect on implant stability and bone height in immediately loaded implant supported mandibular overdenture (randomized clinical trial)

“…Kim et al, [6] suggested a new concept of bone-to-bone biologic fi xation using recombinant human BMP-2 (rhBMP-2)-loaded pedicle screws.…”

Effect of Bone Morphogenetic Protein Coating of Dental Implant: A Systematic Review.

“…They found that the method of application bone morphogenetic protein (BMP-2)was greatly affects the osteoconductivity of dental implant surfaces. (8) used recombinant human bone morphogenetic protein-2 (rhBMP-2)-loaded pedicle screws to formulate a new hypothesis of bone-to-bone biologicallock .…”

“…They concluded that the combination of coating implants with BMP-2 and VEGFcould enhance the bone volume density in the area surrounding the implants, although there was not Bone implant contact observed in this condition. , 2015) (8) used recombinant human bone morphogenetic protein-2 (rhBMP-2)-loaded pedicle screws to formulate a new hypothesis of bone-to-bone biological lock .…”