Initial Evaluation and Management of Knee Pain

Imaging Guidelines

The American College of Radiology recommends beginning with plain radiographs of the knee (minimum two views: anteroposterior and lateral) for all patients ≥5 years old presenting with knee pain, whether acute or chronic 1, 2, 3
For acute trauma, the American College of Radiology suggests using the Ottawa Knee Rules to determine the need for radiographs, which can reduce radiographs by 23-35% while maintaining 100% sensitivity for fractures 4
The American College of Radiology recommends initial radiographs for chronic knee pain, including frontal projection, tangential patellar view, and lateral view 2, 3
If radiographs are normal or show only effusion, the American College of Radiology suggests MRI without contrast as the next step to evaluate soft tissue structures, menisci, ligaments, and bone marrow lesions 1, 2, 3

The American College of Radiology recommends CT without contrast when radiographically occult fractures are suspected or for detailed patellofemoral anatomy evaluation 2, 3
The American College of Radiology suggests ultrasound for confirming effusions, guiding aspiration, detecting Baker cysts, and evaluating superficial structures, but not as a comprehensive screening tool 1, 5, 3
The American College of Radiology recommends joint aspiration when infection or crystal disease is suspected, which can be ultrasound or fluoroscopy-guided 1, 5

The American College of Radiology advises against routine MRI in typical osteoarthritis cases unless symptoms are unexplained by radiographs 1, 2
The American College of Radiology recommends avoiding unnecessary imaging in acute trauma by applying Ottawa rules 4