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. 2022 Jul 9:17:3059-3071.
doi: 10.2147/IJN.S365149. eCollection 2022.

A Novel Calcium Phosphate-Based Nanocomposite for Augmentation of Cortical Bone Trajectory Screw Fixation

Yuetian Wang #  1 , Chun Liu #  2 , Huiling Liu  3 , Haoyong Fu  1 , Chunde Li  1 , Lei Yang  3   4 , Haolin Sun  1
Affiliations

A Novel Calcium Phosphate-Based Nanocomposite for Augmentation of Cortical Bone Trajectory Screw Fixation

Yuetian Wang et al. Int J Nanomedicine. .

Abstract

Purpose: To evaluate the effect of cement augmentation of cortical bone trajectory (CBT) screws using a novel calcium phosphate-based nanocomposite (CPN).

Material and methods: CBT screws were placed into cadaveric lumbar vertebrae. Depending on the material used for augmentation, they were divided into the following three groups: CPN, polymethylmethacrylate (PMMA), and control. Radiological imaging was used to evaluate the cement dispersion. Biomechanical tests were conducted to measure the stability of CBT screws. A rat cranial defect model was used to evaluate biodegradation and osseointegration of the CPN.

Results: After cement augmentation, the CPN tended to disperse into the distal part of the screws, whereas PMMA remained limited to the proximal part of the screws (P < 0.05). As for cement morphology, the CPN tended to form a concentrated mass, whereas PMMA arranged itself as a scattered cement cloud, but the difference was not significant (P > 0.05). The axial pullout test showed that the average maximal pullout force (Fmax) of CPN-augmented CBT screws was similar to that of the PMMA group (CPN, 1639.56 ± 358.21 N vs PMMA, 1778.45 ± 399.83 N; P = 0.745) and was significantly greater than that of the control group (1019.01 ± 371.98 N; P < 0.05). The average torque value in the CPN group was higher than that in the control group (CPN, 1.51 ± 0.78 N∙m vs control, 0.97 ± 0.58 N∙m) and lower than that in the PMMA group (1.93 ± 0.81 N∙m), but there were no statistically significant differences (P > 0.05). The CPN could be biodegraded and gradually replaced by newly formed bone tissue after 12 weeks in a rat cranial defect model.

Conclusion: The biocompatible CPN could be a valuable augmentation material to enhance CBT screw stability.

Keywords: CBT screws; CPN; PMMA; cement augmentation; osteoporotic spine.

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Conflict of interest statement

Professor Lei Yang reports grants from NSFC, China, grants from MOST, China, during the conduct of the study. The authors report no conflicts of interest related to this work.

Figures

Figure 1
Figure 1
Cortical bone trajectory (CBT) screw placement under the guidance of 3D-printed templates and cement injection.
Figure 2
Figure 2
Radiological evaluation of cement-augmented cortical bone trajectory (CBT) screws.
Figure 3
Figure 3
Biomechanical testing of cemented cortical bone trajectory screws.
Figure 4
Figure 4
The results of the setting time and rheological properties.
Figure 5
Figure 5
The results of compressive tests.
Figure 6
Figure 6
Results of biomechanical tests.
Figure 7
Figure 7
Histological analysis of the calcium phosphate–based nanocomposite (CPN) after implantation in a rat cranial defect model.
See this image and copyright information in PMC

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