2025 ISAKOS Biennial Congress ePoster
Evaluation Of Multiligament Knee Injuries: Correlation Between Magnetic Resonance Imaging, Physical Examination, Maximum Manual Varus And Valgus Stress Radiographs, Kneeling Posterior Stress Radiographs, And Digital Rollimeter Measurements
Pedro Henrique Schmidt Alves Ferreira Galvão, MD, MsC, Sao Paulo BRAZIL
Enzo Salviato Mameri, MD, MSc, São Paulo, São Paulo BRAZIL
Felipe Conrado Schumacher, MD, Sao Paulo, SP BRAZIL
Guilherme Mussato, MD, São Paulo, SP BRAZIL
Marcelo De Toledo Petrilli, Md, SAO PAULO, SP BRAZIL
Marcelo S. Kubota, São Paulo, SP BRAZIL
Robert F. LaPrade, MD, PhD, Edina, MN UNITED STATES
Carlos E. S. Franciozi, MD, PhD, Prof., São Paulo, SP BRAZIL
Universidade Federal de São Paulo/Escola Paulista de Medicin, São Paulo, SP, BRAZIL
FDA Status Cleared
Summary
This study evaluates the reliability of physical examination tests for multiligament knee injuries, comparing them with instrumented stability methods and MRI findings, revealing moderate to strong inter-rater reliability but nuanced correlations with objective measures, highlighting the need for a comprehensive diagnostic approach.
ePosters will be available shortly before Congress
Abstract
Background
Multiligament knee injuries (MLKI) pose significant challenges for both diagnosis and treatment. While effective treatment is heavily dependent on a thorough preoperative assessment, the correlation between physical examination and objective diagnostic tools, such as magnetic resonance imaging (MRI) and instrumented stability tests, in these complex injuries is very important.
Objectives
Hypothesis
The aim of the present study is to assess the reliability of physical examination tests in the setting of MLKI, and their validity relative to instrumented stability methods and MRI findings.
Methods
This was a trans-sectional diagnostic study using prospectively collected data from patients diagnosed with MLKI in a single institution, from 2020 to 2024. Five knee surgeons independently performed standardized physical examination maneuvers, including Lachman test, anterior and posterior drawer, varus and valgus stress tests both in extension and at 30º of flexion. Objective instrumented stability was assessed using a digital rolimeter (anterior tibial translation SSD >3mm), stress radiograph (posterior tibial translation SSD ≥8mm), varus stress radiograph (lateral opening ≥2mm for [lateral collateral ligament (LCL), ≥4mm for posterolateral corner (PLC)], and valgus stress radiograph [medial opening ≥3.2mm for medial collateral ligament (MCL), ≥9.8mm for posteromedial corner (PMC) combined with MCL]. MRI findings of evidence of structural tear to each knee ligament were collected. Inter-rater reliability for the physical examination findings among the five observers was calculated using Kendall’s W test. The validity of each physical examination test relative to instrumented stability, and relative to MRI findings was calculated using Cohen’s Kappa.
Results
Forty-six patients were eligible for final inclusion. Inter-rater reliability for all physical examination maneuvers ranged from moderate to strong agreement (Kendall's W 0.58-0.73). Posterior drawer test exhibited moderate agreement with ≥8mm posterior translation on stress radiograph (r=0.532, p<0.001). Varus stress test in extension exhibited fair agreement with ≥4mm lateral opening varus stress radiography (r=0.348, p<0.001). Anterior and posterior drawer tests showed moderate correlation with MRI findings for ACL and PCL tears, respectively (r=0.476, p<0.001 for both). Lachman test showed fair correlation with MRI findings for ACL injury (r=0.38, p<0.001). No statistically significant agreement was found between objective instrumented stability measurements and corresponding MRI findings for any ligament injury assessed (ACL, PCL, LCL, PLC, MCL, MCL combined with PMC).
Conclusion
While physical examination maneuvers for MLKI exhibited moderate to strong inter-rater reliability, their correlation with objective measures such as MRI and instrumented laxity testing is more nuanced. Specifically, the posterior drawer test showed moderate validity in diagnosing PCL injuries compared to stress radiography. However, no significant associations were found between instrumented stability testing and MRI for any of the ligament injuries assessed. These findings suggest that while physical examination remains a valuable tool for initial assessment, it should be used in conjunction with other diagnostic modalities. The lack of strong correlation between objective measures highlights the complexity of multiligament knee injuries and the need for a comprehensive approach to diagnosis, potentially incorporating a combination of clinical examination, imaging, and potentially exam under anesthesia. Further research is warranted to better understand the discrepancies between these objective measures and to develop more accurate diagnostic algorithms for this challenging patient population.