# Diagnostic Accuracy of Non-invasive Tests Versus Arthroscopy in Anterior Cruciate Ligament (ACL) Injuries

## TL;DR

This study compares non-invasive tests like MRI and physical exams to arthroscopy for diagnosing ACL knee injuries, finding them highly accurate.

## Contribution

The study provides empirical evidence on the diagnostic accuracy of MRI and clinical tests for ACL injuries compared to arthroscopy.

## Key findings

- MRI showed high sensitivity (98.57%) and accuracy (96.51%) for detecting ACL tears.
- The Lachman test and Anterior Drawer test also demonstrated high diagnostic accuracy (89.53% and 88.37%, respectively).
- Non-invasive methods are effective alternatives to arthroscopy for ACL injury diagnosis.

## Abstract

Background: The knee joint assessment to detect anterior cruciate ligament (ACL) injury after trauma involves clinical examination and radiography. The gold standard method is doing arthroscopy. We did this study seeking to evaluate the effectiveness of other non-invasive diagnostic methods, including the Anterior Drawer test, Lachman test and magnetic resonance imaging (MRI) in detecting ACL tears after trauma, compared to the reference standard method (the arthroscopy).

Methodology: This descriptive cross-sectional study was conducted in the Orthopaedic Department of the Khyber Teaching Hospital, Peshawar, for six months. A total of 86 participants with knee injuries fulfilling the inclusion criteria were recruited for the study. Mechanism of injury, side of injury and body weight were recorded. The Anterior Drawer test and Lachman test for ACL injury were performed by orthopaedic surgeons with at least five years of post-fellowship experience in orthopaedic surgery. Sensitivities, specificities and accuracy of the clinical tests and MRI were calculated.

Results: The statistical analysis revealed that the mean age of participants was 35.73 (SD 12.7) years, with a range from 18 to 55 years. Among the participants, 67 (77.91%) were male and 19 (22.09%) were female. The side of injury was predominantly right in 50 (58.14%) and left in 36 (41.86%) participants. Road traffic accidents (RTAs) were the leading cause of knee injury, accounting for 63.95% (55) of cases, followed by sports injuries at 23.26% (20).

Regarding diagnostic accuracy, MRI showed a sensitivity of 98.57%, specificity of 87.50% and diagnostic accuracy of 96.51% in detecting ACL tears. The Lachman test demonstrated a sensitivity of 90%, specificity of 87.5% and diagnostic accuracy of 89.53% compared to arthroscopy. Similarly, the anterior Drawer test exhibited a sensitivity of 88.57%, specificity of 87.50% and diagnostic accuracy of 88.37% against the gold standard of arthroscopy. These findings underscore the effectiveness of these diagnostic modalities in identifying ACL injuries.

Conclusions: All three tests (MRI, Lachman test and anterior Drawer test) can be used for the diagnosis of anterior cruciate ligament injury with optimal results.