Work

Influence of implant depth on talus-implant biomechanical behavior in partial talus replacement: a finite element analysis

Year: 2026

Type: article

Abstract: Large, uncontained osteochondral lesions of the talar shoulder (OLTs) remain a surgical challenge. Three-dimensional (3D)-printed partial talar prostheses represent a potential treatment option because, compared with conventional autologous bone grafting, they can restore a smooth articular surface. However, the optimal position of the implant between the cartilage surface and the underlying bone surface remains controversial. Clinical experience suggests that the implant should be placed approximately 1 mm below the cartilage surface, but this empirical recommendation requires quantitative support. A 3D finite element analysis (FEA) model comprising the tibia, fibula, talus, calcaneus, talar prosthesis, corresponding cartilage, and ligaments was developed. Cartilage thickness was set to 1.5 mm, and the prosthesis was positioned flush with the cartilage surface (0 mm) or recessed by 0.5, 1.0, or 1.5 mm. The proximal tibia and fibula were constrained, and loading conditions representing bipedal standing and three positions in the gait cycle were applied. For each loading condition, von Mises stress and strain were calculated. Across the four loading conditions, implants recessed by 0.5 and 1.0 mm exhibited more favorable biomechanical behavior. During bipedal standing, maximum von Mises stress at the bone–implant interface was 0.596 and 0.617 MPa for the 0.5- and 1.0-mm configurations, respectively. These configurations also produced more uniform stress distributions during the gait cycle and lower strain magnitudes, suggesting potentially better long-term stability. Implantation depth significantly affected stress and strain in the talus, cartilage, and prosthesis. Recessing the implant by 0.5–1.0 mm below the talar cartilage surface produced a more favorable stress distribution in this single patient-specific geometric model. However, these in silico findings require experimental validation. Biomechanical study, Level V. Not applicable.

Source: BMC Musculoskeletal Disorders

DOI: 10.1186/s12891-026-10378-y

Authors: Yingdong Zhang, Baozhou Zhang, Heng Li, Zeyu Zhang, Xuewen Wang, Yong Wu

Institutions: Capital Medical University, Beijing Jishuitan Hospital, Peking University

Language: English

Topic: Foot and Ankle Surgery

Subfield: Orthopedics and Sports Medicine

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $3,090