Knee Examination

Subject summary

Knee examination follows the same formula as all orthopaedic examinations: look, feel, move.

  1. Firstly, ask the patient to walk for you. Observe any limp or obvious deformities such as scars or muscle wasting. You should also 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.

    1. Assess walking
      Assess walking

  2. You should get the patient to lie on the bed and make a general observation. Look for symmetry, redness, muscle wasting, scars, rashes or fixed flexion deformities.

    1. Observe patient
      Observe patient

  3. You should 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.

    1. Assess joint temperature
      Assess joint temperature
    2. Palpate the border of the patella
      Palpate the border of the patella
    3. Palpate the joint lines
      Palpate the joint lines
    4. Palpate the point of insertion
      Palpate the point of insertion
    5. Tap the patella
      Tap the patella

  4. The main movements which should be examined both actively and passively are flexion and extension. A full range of movements should be demonstrated and you should feel for any crepitus.

    1. Examine flexion movement
      Examine flexion movement
    2. Examine extension movement
      Examine extension movement

  5. 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, however, if there is 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 you should 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.

    1. Draw test
      Draw test
    2. Posterior lag test
      Posterior lag test
    3. Lateral and medial stress external
      Lateral and medial stress external
    4. Lateral and medial stress internal
      Lateral and medial stress internal