Chapter 14: Knee Exam

INTRODUCTION: CORE PRINCIPLES OF THE JOINT EXAM

Detailed examination of the joints is usually not included in the routine medical examination. However, joint-related complaints are very common, and understanding anatomy and physiology of both normal function and pathologic conditions is critically important when evaluating the symptomatic patient. By gaining an appreciation for the basic structures and function of the joint, the exam becomes more intuitive, and even if you cannot remember the eponym attached to each specific test, you will be able to perform the maneuvers based on your knowledge of the structures that are being tested. A well-performed and well-interpreted joint exam helps to make the correct diagnosis and avoid unnecessary lab and imaging tests.

Historical Clues When Evaluating Any Joint-Related Complaint

• Did the joint pain start acutely, or was it slowly progressive?

• If traumatic, what was the mechanism of injury?

• What is the functional limitation of the joint?

• Are there symptoms within a single joint, or do they affect multiple joints?

• Were there prior problems with the affected area?

• Are there associated systemic symptoms?

Common Approach to the Examination of All Joints

• Make sure the area is well exposed, with no shirt, pants, or other coverings on either side. Use a gown as necessary.

• Understand the normal functional anatomy. What does this joint normally do?

• Carefully inspect the joint(s) in question. Are there signs of inflammation or injury (swelling or redness)? Is there deformity? Because many joints are symmetric, compare with the opposite side.

• Observe the joint while the patient attempts to perform normal activity. What can they do and not do? What specifically limits them?

• Palpate the joint in question. Is there warmth or point tenderness? If so, over what anatomic structure(s)?

• Assess the range of motion (ROM). Check active ROM (patient moves the joint). Then check passive ROM (you move it) if active ROM is limited or causes pain.

• Perform a strength and neurovascular assessment. See chapters on the cardiovascular (Chapter 6) and neurologic (Chapter 12) exams for details.

• Proceed with joint-specific provocative maneuvers related to pathology occurring in the affected joint (see descriptions in this chapter as well as Chapter 15, the shoulder exam).

• In the setting of acute injury and pain, it is often very difficult to assess a joint because the patient “protects” the affected area, limiting movement and thus your examination. It helps to examine the unaffected side first, as this gains the patient’s confidence and allows you to develop a sense of their normal.

NORMAL ANATOMY AND FUNCTION OF THE KNEE

The knee is a hinge-type joint, with most of the movement related to flexion and extension via the use of powerful muscles in the upper leg. There is also some ...