Effects of condensation and compressive strain on implant primary stability: A longitudinal, in vivo, multiscale study in mice

Zhijun Li; Masaki Arioka; Yindong Liu; Maziar Aghvami; Serdar Tulu; John B Brunski; Jill A Helms

doi:10.1302/2046-3758.92.BJR-2019-0161

Effects of condensation and compressive strain on implant primary stability: A longitudinal, in vivo, multiscale study in mice

Bone Joint Res. 2020 May 16;9(2):60-70. doi: 10.1302/2046-3758.92.BJR-2019-0161. eCollection 2020 Feb.

Authors

Zhijun Li¹, Masaki Arioka², Yindong Liu³, Maziar Aghvami⁴, Serdar Tulu⁴, John B Brunski⁴, Jill A Helms⁴

Affiliations

¹ Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, California, USA; Orthopedic surgeon, Department of Orthopedics, Tianjin Medical University General Hospital, Tianjin, China.
² Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, California, USA; Assistant professor, Department of Clinical Pharmacology, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan.
³ Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, California, USA; Oral surgeon, State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China.
⁴ Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, California, USA.

Abstract

Aims: Surgeons and most engineers believe that bone compaction improves implant primary stability without causing undue damage to the bone itself. In this study, we developed a murine distal femoral implant model and tested this dogma.

Methods: Each mouse received two femoral implants, one placed into a site prepared by drilling and the other into the contralateral site prepared by drilling followed by stepwise condensation.

Results: Condensation significantly increased peri-implant bone density but it also produced higher strains at the interface between the bone and implant, which led to significantly more bone microdamage. Despite increased peri-implant bone density, condensation did not improve implant primary stability as measured by an in vivo lateral stability test. Ultimately, the condensed bone underwent resorption, which delayed the onset of new bone formation around the implant.

Conclusion: Collectively, these multiscale analyses demonstrate that condensation does not positively contribute to implant stability or to new peri-implant bone formation.Cite this article: Bone Joint Res. 2020;9(2):60-70.

Keywords: Biomechanical; Bone resorption; Implant; Osseointegration.

Grants and funding

R01 DE024000/DE/NIDCR NIH HHS/United States