Which examination signs are used to assess knee joint effusion?

Which examination signs are used to assess knee joint effusion?

• A. Lachman test
• B. Bulge sign
• C. McMurray test
• D. Apley grind

Answer: (B)

Detecting knee effusion is best assessed with the bulge sign. In this exam, with the patient lying flat and the knee straight, the clinician gently milks fluid from the suprapatellar area toward the center and then tests for a small wave or bulge on the medial side as the fluid shifts. A visible or palpable bulge indicates excess joint fluid, i.e., effusion. The other tests—Lachman for ACL stability, McMurray for meniscal tears, and Apley grind for meniscal pathology—focus on ligaments or cartilage rather than fluid in the joint, so they don’t specifically indicate effusion.

Detecting knee effusion is best assessed with the bulge sign. In this exam, with the patient lying flat and the knee straight, the clinician gently milks fluid from the suprapatellar area toward the center and then tests for a small wave or bulge on the medial side as the fluid shifts. A visible or palpable bulge indicates excess joint fluid, i.e., effusion. The other tests—Lachman for ACL stability, McMurray for meniscal tears, and Apley grind for meniscal pathology—focus on ligaments or cartilage rather than fluid in the joint, so they don’t specifically indicate effusion.