UNMASKING PARTIAL ACL TEARS: THE EDGE OF DYNEELAX & GNRB ARTHROMETERS OVER MRI

MRI has long been heralded as a reliable, non-invasive imaging modality for assessing soft tissue injuries. In many instances, it effectively elucidates complete ACL tears, characterizing the disruption of fiber continuity and associated findings like bone bruising. Yet, when it comes to partial ACL ruptures, the MRI narrative becomes more intricate.

Partial ruptures involve a portion of the ACL fibers being torn while others remain intact. Given the intricacies of ligamentous fibers and the variations in their alignment, MRI may not always capture these nuanced tears. The following factors contribute to this diagnostic challenge:

1. Signal Variability: The MRI signal can vary based on the patient's position, type of injury, and time since injury. In cases of partial ACL ruptures, the presence of intact fibers might overshadow the torn portion, leading to a potential underestimation of the injury's severity.
2. Tissue Edema: Swelling and fluid accumulation in and around the ACL can mask the true extent of fiber disruption, making differentiation between a partial tear and other knee pathologies challenging.

In light of the limitations associated with MRI, the medical community has sought additional diagnostic tools. Knee laxity arthrometers, like the Dyneelax or GNRB, have emerged as pivotal in assessing ACL integrity (read downloadable study of Théo Cojean - 2023 below).

These devices measure the degree of anterior tibial translation relative to the femur, thus quantifying knee laxity. The advantages of using knee laxity arthrometers include:

• Enhanced Sensitivity: Dyneelax and GNRB have shown a heightened ability to detect partial ACL ruptures, often surpassing MRI's sensitivity in this regard. By directly quantifying functional laxity, these arthrometers can identify subtle shifts in ACL integrity.
• Objectivity: Arthrometers provide a quantitative assessment of knee laxity, which contrasts with the sometimes subjective nature of MRI interpretations.
• Cost-Effective: Arthrometric testing is considerably cheaper than MRI, making it a more accessible diagnostic tool for a broader range of patients.
• Immediate Results: While MRI requires interpretation, arthrometers deliver instant feedback during a clinical exam.
• User-Friendliness: With minimal training, clinicians can use arthrometers effectively, ensuring consistent and reliable results.
• Price: Arthrometers, being less technologically complex than MRI machines, are often available at a fraction of the cost, making them a favorable option for many clinics and hospitals.
• Making Space in MRI Rooms: In France, studies have found that MRI is often over prescribed. Using knee arthrometers as first instance when suspecting a knee ligament injury makes space for patients who suffers other pathologies and who are in dire need of an MRI Scan.