Assessment of Laxity in Multiligamentous Knee Injuries Using Stress Radiographs: A Simple Technique for a Busy Clinic

Area of Science:

• Orthopedic surgery
• Radiology
• Sports medicine

Background:

• Multiligamentous knee injuries require individualized treatment.
• Stress radiographs objectively quantify knee laxity but are not widely taught.
• Accurate diagnosis of knee instability is crucial for effective treatment.

Purpose of the Study:

• To establish a reproducible method for acquiring stress radiographs.
• To standardize the technique for assessing knee laxity.
• To improve diagnostic accuracy for knee ligament injuries.

Main Methods:

• Coronal laxity assessment involves specific knee flexion, beam angulation, and applied forces (valgus/varus) to evaluate MCL and LCL.
• Sagittal laxity assessment utilizes knee flexion and gravity to measure tibial sag.
• The LaPrade method is used for joint space width measurement in coronal laxity assessment.

Main Results:

• The described techniques allow for objective measurement of coronal and sagittal knee laxity.
• A side-to-side difference in stress radiographs can indicate significant ligamentous injury, such as Grade 3 MCL, LCL, and PCL tears.
• The case example demonstrated findings consistent with a complex knee injury.

Conclusions:

• Stress radiographs provide objective data for diagnosing complex knee injuries.
• These imaging techniques enhance the assessment of knee stability.
• The methods are cost-effective, efficient, and valuable for clinical decision-making in managing knee injuries.