Anatomical Analysis of the Femoral Insertions of the Lateral Collateral Ligament and Popliteal Tendon in the Chilean Population: A Magnetic Resonance Imaging Study

Abstract

Injuries to the posterolateral corner (PLC) of the knee can significantly impair stability and function. In particular, variations in the femoral insertions of the lateral collateral ligament (LCL) and popliteal tendon (PT) may affect surgical planning for PLC injuries. However, these anatomical features are underexplored in the Chilean population. This study seeks to characterize the femoral insertions of the LCL and PT in Chilean patients based on magnetic resonance imaging (MRI) findings. This cross-sectional, observational study was conducted at a single center, including 43 patients aged 18 and older who underwent knee MRI scans. Imaging was performed using a 1.5 Tesla MRI scanner with isotropic voxel dimensions of 0.65 × 0.65 × 0.65 mm. Two musculoskeletal radiologists independently measured the distance between the centroids of the LCL and PT insertion points on the femur. An intraclass correlation coefficient (ICC) was calculated to assess interobserver reliability, and a paired t-test was used to compare the measurements. A p-value < 0.05 was considered statistically significant. Among the 43 patients (51.2% male, 48.8% right knees), the average distance between the LCL and PT insertion centroids was 11.7 mm (standard deviation: 1.61). The measurements by the two radiologists were similar (observer 1: 11.5 mm; observer 2: 11.8 mm), with no significant differences (p = 0.326). The ICC for interobserver agreement was 0.83 (95% confidence interval: 0.69–0.91), indicating high reliability. In this Chilean cohort, the average distance between the LCL and PT femoral insertions was 11.7 mm, a value that differs from previously reported ranges. These findings may help refine surgical approaches to PLC injuries.

Level of evidence

Level III, cross-sectional observational study.

Keywords

posterolateral corner - lateral collateral ligament - popliteal tendon - distance - insertions

Data Availability Statement

We also declare that all information and dataset related to the study is available in digital format at https://drive.google.com/drive/folders/1mZHjcuJdt0_dXu5CeEeXelUIIRr1mMLy and can be shared upon a reasonable request for academic purposes only.

Ethical Approval

The authors of this study declare that the following work has received approval from the ethics committee of our hospital (Comité de Ética Clínica del Hospital del Trabajador), and we consent to its publication.

Publication History

Received: 29 October 2024

Accepted: 25 November 2025

Accepted Manuscript online:
27 November 2025

Article published online:
08 December 2025

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