Recovery of Forearm Bone Strength After Plate Removal: A Finite Element Analysis Study

Yusuke Matsuura; Takane Suzuki; Tomoyo Akasaka; Aya Kanazuka; Yoshihito Ozawa; Yuki Shiko; Seiji Ohtori

doi:10.1016/j.jhsa.2022.07.017

Recovery of Forearm Bone Strength After Plate Removal: A Finite Element Analysis Study

J Hand Surg Am. 2022 Sep 16:S0363-5023(22)00460-9. doi: 10.1016/j.jhsa.2022.07.017. Online ahead of print.

Authors

Yusuke Matsuura¹, Takane Suzuki², Tomoyo Akasaka³, Aya Kanazuka⁴, Yoshihito Ozawa⁵, Yuki Shiko⁵, Seiji Ohtori⁴

Affiliations

¹ Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Chou-Ku, Chiba city, Chiba, Japan. Electronic address: y-m-1211@khaki.plala.or.jp.
² Department of Bioenvironmental Medicine, Graduate School of Medicine, Chiba University, Chou-Ku, Chiba city, Chiba, Japan.
³ Department of Rehabilitation Medicine, Graduate School of Medicine, Chiba University, Chou-Ku, Chiba city, Chiba, Japan.
⁴ Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Chou-Ku, Chiba city, Chiba, Japan.
⁵ Clinical Research Center, University of Chiba, Chiba, Japan.

PMID: 36123221
DOI: 10.1016/j.jhsa.2022.07.017

Abstract

Purpose: The purpose of this study was to estimate the bone strength after plate removal over time and to investigate the progression of bone strength recovery.

Methods: A consecutive series of 31 patients was investigated to evaluate bone strength before and after forearm plate removal. Patients who were included underwent plate fixation for forearm diaphyseal fractures and were scheduled for plate removal. Computed tomography (CT) scans of the entire length of the bilateral forearms were taken before plate removal and at 1, 3, and 6 months after surgery. Patient-specific CT-based finite element analysis was used to predict the forearm bone fracture strength against an axial load (N), defined as the bone strength. Bone strength was estimated by patient-specific CT-based finite element analysis at each time point.

Results: The mean age of the patients was 40.4 years. The mean time between plate fixation and removal was 27.5 months. Bone strength before the removal was estimated as reduced to 47% of that of the uninjured side. This was constant regardless of age group, involvement of the radius or ulna, Arbeitsgemeinschaft für Osteosynthesefragen (AO) classification, open fracture, or type of plate. Bone strength at 1, 3, and 6 months after removal was estimated to be 66%, 85%, and 97%, respectively. The bone strength of the distal ulna was weaker than that at the other sites in the forearm and showed delayed recovery.

Conclusions: Bone strength after plate removal showed recovery within 3-6 months and was fully recovered by 6 months. The degree of recovery of bone atrophy varies from site to site, and patients should be careful about refracture after removal.

Clinical relevance: Clinicians should be aware that bone strength may not be sufficiently restored even 6 months after plate removal of forearm fractures.

Keywords: Forearm fracture; bone atrophy; finite element analysis; locking plate; plate fixation.