Potential of Titanium Pins Coated with Fibroblast Growth Factor-2-Calcium Phosphate Composite Layers to Reduce the Risk of Impaired Bone-Pin Interface Strength in the External Fixation of Distal Radius Fractures

Hirotaka Mutsuzaki; Yohei Yanagisawa; Hiroshi Noguchi; Atsuo Ito; Masashi Yamazaki

doi:10.3390/jcm13113040

Potential of Titanium Pins Coated with Fibroblast Growth Factor-2-Calcium Phosphate Composite Layers to Reduce the Risk of Impaired Bone-Pin Interface Strength in the External Fixation of Distal Radius Fractures

J Clin Med. 2024 May 22;13(11):3040. doi: 10.3390/jcm13113040.

Authors

Hirotaka Mutsuzaki^{1

2}, Yohei Yanagisawa³, Hiroshi Noguchi⁴, Atsuo Ito⁵, Masashi Yamazaki⁴

Affiliations

¹ Center for Medical Science, Ibaraki Prefectural University of Health Sciences, Ami 300-0394, Japan.
² Department of Orthopedic Surgery, Ibaraki Prefectural University of Health Sciences Hospital, Ami 300-0331, Japan.
³ Department of Emergency Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8575, Japan.
⁴ Department of Orthopaedic Surgery, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8575, Japan.
⁵ Health and Medical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), AIST Tsukuba Central 6, 1-1-1 Higashi, Tsukuba 305-8566, Japan.

Abstract

Background: The risk of impaired bone-pin interface strength in titanium (Ti) pins coated with fibroblast growth factor (FGF)-calcium phosphate (CP) composite layers is yet to be evaluated in a clinical study. This retrospective study used Weibull plot analysis to evaluate bone-pin interface strength in Ti pins coated with FGF-CP layers for external distal radius fracture fixation. Methods: The distal radial fractures were treated with external fixation. The FGF-CP group comprised five patients (all women, aged 70.4 ± 5.9 (range: 62-77) years), and the uncoated pin group comprised ten patients (eight women and two men, aged 64.4 ± 11.7 (range: 43-83) years). The pins were removed after six weeks. The insertion and extraction peak torques were measured. The extraction peak torque was evaluated using Weibull plot analysis. Results: We compared the extraction torque of the two groups at or below 506 Nmm for a fair comparison using Weibull plot analysis. The Weibull plots were linear for both the FGF-CP and uncoated pin groups. The slope of the regression line was significantly higher in the FGF-CP group (1.7343) than in the uncoated pin group (1.5670) (p = 0.011). The intercept of the regression line was significantly lower in the FGF-CP group (-9.847) than in the uncoated pin group (-8.708) (p = 0.002). Thus, the two regression lines significantly differed. Conclusions: Ti pins coated with FGF-CP layers exhibit the potential to reduce the risk of impaired bone-pin interface strength in the external fixation of distal radius fractures.

Keywords: Weibull plot analysis; calcium phosphate; coating; distal radius fractures; external fixation; fibroblast growth factor-2 (FGF-2); impaired bone fixation.

Grants and funding

This study was supported by a grant from the Initiative for Accelerating Regulatory Science in Innovative Drug, Medical Device, and Regenerative Medicine of the Ministry of Health, Labour and Welfare, Japan.