Stress Radiographs of the Knee
The most commonly injured area of the knee is the MCL, or medial collateral knee ligament, and stabilizers in the medial knee [3,4]. Physical examination is one of the first steps in diagnosis of knee injuries. This will usually include a valgus stress to the medial knee ligaments at both full extension and 30 degrees of knee flexion. Many providers will grade MCL injuries depending on this. The grading of these injuries depends both on relaxation of the patient and clinician’s ability to detect an endpoint. Many also describe laxity at full extension to be indicative of a and MCL and cruciate ligament injury [4,12]. Clinician experience, patient pain tolerance or guarding, and concurrent ligamentous injuries may skew physical examination interpretation, detracting in certain situations from its clinical use. This provides a more objective method of measuring medial knee injuries.
Image 1. Illustration of the lateral side of the knee including the LCL, popliteus tendon and more (adopted from )
Image 4. Demonstration of the flexed knee view at 20 degrees.
Image 6. Anatomy illustration of the ACL, PCL and other stabilizing structures (adopted from )
Image 7. Demonstration of kneeling stress radiographs toe valuation the stability of the PCL (adopted from )
Image 8. Xray of kneeling stress radiographs showing increased posterior translation suggesting a PCL tear (Adopted from )
Image 9. Anterior stress radiographs can also evaluate PCL integrity