Knee examination is part of a physical examination or when a patient presents with knee pain or a history that suggests a pathology of the knee joint. The examination follows the same formula as all orthopaedic examinations: look, feel, move.
To begin, ask the patient to walk for you. Observe any limp or obvious deformities such as scars or muscle wasting. Check if the patient has a varus (bow-legged) or valgus (knock-knees) deformity. Also observe from behind to see if there are any obvious popliteal swellings such as a Baker's cyst.
Ask the patient to lie on the bed and make a general observation. Look for symmetry, redness, muscle wasting, scars, rashes, or fixed flexion deformities.
Now feel the joint. Check the temperature using the backs of your hands, comparing it with other parts of the leg.
Palpate the border of the patella for any tenderness, behind the knee for any swellings, along all of the joint lines for tenderness and at the point of insertion of the patellar tendon.
Finally, tap the patella to see if there is any effusion deep to the patella.
The main movements which should be examined both actively and passively are:
A full range of movements should be demonstrated and you should feel for any crepitus.
There are a number of special tests which should also be performed.
Flex the knee to 90 degrees and sit on the patient's foot. Pull forward on the tibia just distal to the knee. There should be no movement. If there is however, it suggests anterior cruciate ligament damage.
With the knee in the same position, look for any posterior lag of the joint, this suggests posterior cruciate damage.
Finally, hold the leg with the knee flexed to 15 degrees and place lateral and medial stress on the knee. Any excessive movement suggests collateral ligament damage.
On completion, thank the patient for their time and wash your hands.