Question 1

What anatomical structures make the knee joint inherently unstable?

Accepted Answer

The knee is held together by various ligaments and supported by menisci, which act as shock absorbers and increase the contact area of the joint. The patella, the largest sesamoid bone in the body, lies in front and acts as a fulcrum for forceful knee extension. Despite being the largest joint in the body, this complex arrangement creates inherent instability.

Question 2

How do you perform palpation to detect knee effusion?

Accepted Answer

With the patient supine, assess for swelling around the kneecap by milking down from above and below the knee. Push down on the patella with your finger to appreciate any fluid above and below it. Swelling in front suggests pre-patella bursitis, while fluid behind the patella indicates knee joint effusion and likely significant internal derangement.

Question 3

What does tenderness at the tibial tubercle indicate?

Accepted Answer

The tibial tubercle is the insertion site of the patella tendon on the anterior proximal tibia. Tenderness at this location may suggest Osgood-Schlatter's disease in children and adolescents. Palpating this roughened protrusion helps identify this common overuse injury in younger patients.

Question 4

What is the normal range of motion for knee flexion?

Accepted Answer

Normal knee flexion should allow the heel to come as close to the buttocks as possible, with a range of approximately 130 degrees. Limited flexion can indicate joint effusion or quadriceps spasm. Testing flexion while the patient is supine helps assess the integrity of the knee joint.

Question 5

How do the Lachman test and Anterior Drawer test differ in assessing ACL injury?

Accepted Answer

The Lachman test flexes the knee to 20 degrees, pulling forward on the proximal tibia while pushing down on the femur to feel for an endpoint as the ACL gets stressed. The Anterior Drawer test bends the knee with the foot flat, pulling the tibia forward to check for abnormal movement. Both evaluate anterior cruciate ligament integrity but use different knee positions.

Question 6

What does a positive Sag sign indicate about the posterior cruciate ligament?

Accepted Answer

The Sag sign test observes whether the tibia sags or drops back with respect to the femur when the knee is flexed to 90 degrees with the foot flat on the exam table. Presence of this sign may suggest a PCL tear with significant posterior laxity. Comparing both sides helps identify abnormal posterior displacement.

Question 7

What does the Q-angle measurement assess in knee examination?

Accepted Answer

The Q-angle is formed by a line connecting the anterior superior iliac spine and patella center, with a line from the patella center down to the tibial tubercle. Angles greater than 10 degrees in males and 15 degrees in females suggest predisposition to patellofemoral problems. This measurement helps identify anatomical risk factors for knee dysfunction.

Knee Exam - Assessment Quiz