How can a knee joint effusion be checked?

• A. By performing the bulge sign test or ballotment test
• B. By assessing for joint crepitus
• C. By palpating the medial and lateral tibial plateau
• D. By measuring the ROM of the knee

Answer: (A)

A knee joint effusion can be effectively assessed using specific tests designed to detect fluid accumulation within the joint space. The bulge sign test and the ballotment test are two clinical techniques that help identify the presence of effusion clearly.

The bulge sign test involves stroking the medial aspect of the knee to push fluid down toward the lateral side, where it can be observed as a bulge in the soft tissue. If a bulge is seen, it indicates a positive sign of joint effusion. The ballotment test, on the other hand, entails pushing the patella down against the femur to determine if there is fluid that can be displaced, which also signifies the presence of effusion.

These specific tests are designed to directly assess fluid dynamics in the knee joint, making them the most appropriate choices for confirming knee joint effusion. Other options, such as measuring the range of motion (ROM) or assessing for joint crepitus, may provide useful information regarding overall joint function but do not directly evaluate for the presence of fluid in the joint space. Similarly, palpating the tibial plateau provides insight about bony structures but does not directly indicate the presence of effusion.