Conference

International Society of Orthopaedic Surgery and Traumatology - Orthopaedic World Congress

Document Type

Poster

Date

9-3-2025

Abstract

Purpose: Knee effusion after anterior cruciate ligament (ACL) injury and reconstruction is associated with quadriceps dysfunction and may contribute to early osteoarthritis development. This study was subsequently designed to determine the intra-rater and inter-rater reliability of our method for volumetric quantitative measurements of knee effusion using T2-weighted magnetic resonance imaging (MRI) after ACL injury and reconstruction.

Methods: MRIs of 10 ACL-injured knees and 10 uninjured knees from participants aged 15-35 years old were included. Exclusion criteria included previous knee injury/surgery, inflammatory disease, BMI >30 kg/m2, and concomitant grade III ligament tears. Two independent raters analyzed effusion volumes using custom MATLAB software on T2-weighted axial sequences. Measurements were standardized using the three-column concept for the tibial region and anatomical landmarks in the femoral region. Intra- and inter-rater reliability was assessed using intraclass correlation coefficients (ICC) with minimal detectable changes calculated. Measurement agreement was assessed using Bland-Altman plots.

Results: Effusion volumes were higher in the injured compared to uninjured knees (10.80±7.40 mL vs 1.84±0.69 mL, p< 0.05). Volumetric effusion measurements demonstrated excellent intra-rater (ICC=0.993, 95% CI: 0.981-0.997) and inter-rater reliability (ICC=0.974, 95% CI: 0.907-0.991). The minimal detectable change was 0.13 mL for intra-rater measurements and 0.46 mL for inter-rater measurements. Bland-Altman plots revealed no systematic bias between raters.

Conclusions: Volumetric quantitative measurements using standard T2-weighted axial MRI sequences provide a highly reliable assessment of knee effusion after ACL injury and reconstruction. This non-invasive measurement technique offers potential for objective clinical assessment and longitudinal monitoring without requiring specialized imaging sequences.

Rights

2025 Copyright, the authors

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