Development of a Novel Hybrid Suture Anchor for Osteoporosis by Integrating Titanium 3D Printing and Traditional Machining

Chih-Hwa Chen; Wen-Jen Chang; Yu-San Chen; Kuan Hao Chen; Shao-Fu Huang; Hsin-Ru Hsueh; Cun-Bin Li; Chun-Li Lin

doi:10.18063/ijb.v8i4.608

Development of a Novel Hybrid Suture Anchor for Osteoporosis by Integrating Titanium 3D Printing and Traditional Machining

Int J Bioprint. 2022 Aug 26;8(4):608. doi: 10.18063/ijb.v8i4.608. eCollection 2022.

Authors

Chih-Hwa Chen^{1

2

3}, Wen-Jen Chang^{4

5}, Yu-San Chen⁶, Kuan Hao Chen^{2

7}, Shao-Fu Huang^{6

8}, Hsin-Ru Hsueh⁶, Cun-Bin Li⁶, Chun-Li Lin^{6

8}

Affiliations

¹ School of Biomedical Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei, Taiwan.
² Department of Orthopedics, Taipei Medical University - Shuang Ho Hospital, New Taipei City, Taiwan.
³ School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
⁴ Department of Information Management, Chang Gung University, Tao-Yuan, Taiwan.
⁵ Department of Dentistry, Chang Gung Memorial Hospital, Taoyuan, Taiwan.
⁶ Department of Biomedical Engineering, National Yang Ming Chiao Tung University, Taipei, Taiwan.
⁷ Graduate Institute of Biomedical Materials and Tissue Engineering, College of Biomedical Engineering, Taipei Medial University, Taipei, Taiwan.
⁸ Innovation and Translation Center of Medical Device, National Yang Ming Chiao Tung University, Taipei, Taiwan.

Abstract

The aim of this study is to develop a titanium three-dimensional (3D) printing novel hybrid suture anchor (HSA) with wing structure mechanism which can be opened to provide better holding power for surrounding osteoporotic bone. A screw-type anchor (5.5-mm diameter and 16-mm length) was designed with wing mechanism as well as micro dual-thread in the outer cortex bone contact area and macro single-thread in the anchor body. Both side wings can be opened by an internal screw to provide better bone holding power. The suture anchor and internal screw were manufactured using Ti6Al4V 3D printing and traditional machining, respectively. Static pullout and after dynamic 300-cyclic load (150 N) pullout tests for HSA with or without the wing open and commercial solid anchor (CSA) were performed (n = 5) in severely osteoporotic bone and osteoporotic bone to evaluate failure strengths. Comparison of histomorphometrical evaluation was performed through in vivo pig implantation of HSAs with the wing open and CSAs. The failure strengths of HSA with or without the wing open were 2.50/1.95- and 2.46/2.17-fold higher than those of CSA for static and after dynamic load pullout tests in severely osteoporotic bone, respectively. Corresponding values for static and after dynamic load pullout tests were 1.81/1.54- and 1.77/1.62-fold in osteoporotic bone, respectively. Histomorphometrical evaluation revealed that the effects of new bone ingrowth along the anchor contour for CSA and HSA were both approximately 20% with no significant difference. A novel HSA with wing mechanism was developed using 3D printing and the opened wing mechanism can be used to increase bone holding power for osteoporosis when necessary. Better failure strength of HSA than CSA under static and after dynamic load pullout tests and equivalence of bone ingrowth along the anchor contours confirmed the feasibility of the novel HSA.

Keywords: 3D printing; Failure strength; Pullout; Rotator cuff; Suture anchor.