Physical Examination of the Knees

Introduction 

the typical knee examination involves two distinct groups 

• young knees
• old knees

Index

• GIEP - don't forget!
• Inspection
• functional assessment
• gait examination
• inspection of the anterior knee
• inspection of the posterior knee
• Palpation
• temperature
• tenderness
• Movements
• Measurements
• muscle wasting
• Special tests
• anterior drawer test
• lachman
• posterior drawer test
• mcmurrey's test
• apley's test
• patellar apprehension test
• dial test

inspection

inspection may be done after asking the patient to walk (gait inspection). if the patient is unable to walk, the inspection of the knee may be the first thing we may do.

gait inspection

• asymmetry in gait
• stance phase
• swing phase
• any pain while walking

focal inspection of knee 

look for any signs of;

• scars
• sinuses
• redness
• rashes
• common gross deformities
• genu varum
• Knock-knee appearance - the legs bend inwards
• genu valgum
• bow-legged appearance - the legs bend outwards
• loss of muscle baulk
• muscle baulk will noticeably reduce once the patient stops using the joint - as early as 2 weeks from the beginning of inactivity. 
• the wasting becomes more apparent if you ask the patient to tense the muscle on the quads - which may be achieved by asking the patient to push into the couch / bed with their knees.
• if any muscle wasting is expected or suspected, remember to measure the girth of the quadriceps muscle. (discussed later)
• look at the posterior knee as well - more easier when patient is standing.

palpation

before every palpation, please ask for presence of pain and tenderness on the region of palpation. 

also, obtain permission. 

• temperature
• very easily missed - do it first because;
• it is often missed
• the temperature may change with manupilation and palpation of patient
• do it distal-proximal, because distal parts of body are often colder.
• feel if there is a swelling. different pathologies have different characteristic swellings;
• osteoarthritis
• rheumatoid arthritis
• gouty arthritis
• 
  
• feel for the bony prominances, joint line, and ask for tenderness
• tibial tubercle - important in paeds, patient with oshgood-schlatter's Disease may have tenderness here due to fragments of bone in the apophysis.
• apex of patella
• feel the ligaments - ask for tenderness
• patellar tendon
• quadricep tendon
• medial collateral ligament
• lateral collateral ligament
• feel the patellofemoral ligament by tilting the patella.
• you may also feel for the posterior fossa of the knee for any cysts as well.
• feel for fluid in the knee - first, ask yourself if the fluid (if present) is inside or outside the knee joint. if outside, it may suggest prepatellar bursitis. most of the time, the fluid is inside the knee - and test for effusion are;
• patellar tap
• suitable for moderate to large joint effusion
• move any fluid from the medial and lateral compartments into the retropatellar space
• apply firm pressure onto the patella into the retropatellar space
• feel if the patella tap onto the lateral demoral condyle, and bounces back into the hand as it floats back up.
• bulge sign
• suitable for minimal to moderate joint effusion
• hold the patella still from the superior border of the patella
• empty the medial joint recess using a wiping motion with index finger
• apply a similar wiping motion to the lateral recess
• watch the medial recess.
• if fluid is present, distinct bulge should appear on the medial surface

movements

• passive movements
• you may want to move the patient's knees, placing one hand over the joint and the other doing the movements.
• flexion
• extension
• ask patient to straighten the knee
• hyperextension
• assess by watching the knee as you hold the feet by the heel off the bed from the foot of the bed
• ask patient to relax, holding both feets in level. 
• ensure there is no discomfort.
• active movements
• you may ask the patient to move the knee as you place your hand over the joint - to feel for any crepitus.
• active movement limitation may be caused by;
• muscular problem
• pain
• ligament disintegrety 

measurements

• measurement of the calf for detection of muscle wasting can be done - make sure the measurement of the diameter is done at the same level on the quadriceps muscle. a good landmark to use is the tibial tuberosity - 20cm above the tuberosity may be a nice position to do so.

special tests (rather ineffective to be *read*. please watch some kind of videos)

• anterior drawer test
• checks the integrity of the anterior cruciate ligament - which prevents anterior subluxation of the knee. 
• patient's knee at 90 degrees, and examiner will tug onto the tibia
• lachman
• able to check integrety of both anterior and posterior ligaments.
• examiner will place one hand on the thigh of patient, and one hand will firmly grasp the upper tibia, and attempt to move the tibia anteriorly and posteriorly relative to the thigh.
• posterior drawer test
• checks the integrety of posterior cruciate ligament.
• the anterior sag sign should be noted before this test.
• mcmurray's test
• checks integrity of the meniscus. 
• examiner's hands on the joint line.
• a valgus stress to the knee whilst the other hand rotates the leg externally and extends the knee.  Pain and/or an audible click while preforming this maneuver can indicate a torn medial meniscus
• full flexion varus stress to the knee and medial rotation to the tibia prior to extending the knee once again - to check the lateral meniscus.


• apley's test
•  patient in the prone position with the knee flexed to 90 degrees, The patient's thigh is then fixed to the examining table by means of hand / examiner's knee. The examiner laterally and medially rotates the tibia, combined first with distraction, while noting any excessive movement, restriction or discomfort. 
• if pain and abnormal movement noted here, suggests ligamentous pathology.
• patient in same position, but with the examiner pushing the tibia into the knee (downwards), with rotational force as if grinding on the menisci.
• if pain and restricted movement compared to normal side noted here, suggests meniscus tear.
• patellar apprehension test
• assess the possibility of spontaneously reduced patellar dislocation.
• patient lies with 20-30deg. flexion of knee, examiner will than attempt to laterally displace the patella. 
• test is positive with patient apprehending / stopping the examiner.

lastly...

comment on the hip examination - that you would like to examine the hips for a knee complaint - to rule out referred pain from the hips. 

wash hands.