E2257. Ultrasound Evaluation of Five Interesting Pathologies at the Knee Joint
  1. Joseph Craig; Henry Ford Hospital
  2. Chad Klochko; Henry Ford Hospital
Ultrasound is useful for evaluating specific structures and pathologies of the knee joint. These include the common peroneal nerve, quadriceps, and patellar tendon rupture; joint effusion aspiration and injection; and evaluation of Baker’s cyst. These studies are normally performed to answer a specific clinical question.

Educational Goals / Teaching Points
1. Review the normal anatomy of the common peroneal nerve and common peroneal intraneural and intra/extraneural ganglia. 2. Review the normal ultrasound appearances of the quadriceps and patellar tendons and quadriceps and patellar tendon rupture. 3. Review the normal appearance of effusion on ultrasound. Discuss ultrasound-guided aspiration. 4. Display some typical examples of inflammatory arthritis (septic arthritis and gout). 5. Review the anatomy of the Baker’s cyst and display examples of rupture including hemorrhagic and deep rupture.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Anatomic/pathophysiologic issues, imaging findings: We review five interesting pathologies at the knee joint with the emphasis on ultrasound imaging. We show normal and abnormal common peroneal nerve, normal and torn extensor mechanism, no effusion and effusion at the knee joint, and simple and complex fluid. We also show hyperemia and synovial proliferation in inflammatory arthritis. Finally, normal anatomy with no Baker’s cyst and simple and complex ruptured cysts are displayed. Some of our cases have MR correlation.

1. Targeted ultrasound approach is very useful for specific pathologies of the knee. 2. Ultrasound can frequently answer specific clinical questions at the knee, particularly extensor tendon rupture and Baker’s cyst rupture. 3. In more complex cases, ultrasound evaluation can add extra information in conjunction with MR. 4. The knee joint can be reliably aspirated and injected under ultrasound guidance.