Knee Joint Examinations

1.) Look (Inspection)

- With patient standing, look for knee deformity (valgus- knock knee, related to rheumatoid arthritis and varus- bow-leg related to osteoarthritis.

- In the walking patient, the following features are checked

• The toeing angle: angle between axis of foot and direction of walking. Normally, axis points laterally, with an angle of 10-15 degrees.
• Tilting of knee with single-leg stance: This can be seen with bone wear (osteoarthritis) or ligamentous problems

- With patient lying down (supine) with both knees and thighs fully exposed, look for any abnormalities. Compare both sides.

• Note any wasting of quadriceps muscle, atrophy
• Skin changes- redness, scars, swelling and deformity
• Is there swelling of synovium/ knee effusion?

2.) Feel (Palpation)

- Feel for quadriceps wasting.

- Palpate over knees for warmth and synovial swelling

- Perform the Patellar tap- Use left hand to force fluid out of suprapatellar pouch, gently press patella into femur. The patellar will spring back due to a small effusion.

- Use the bulge sign for smaller effusions- Compress the suprapatellar pouch with your left hand and anchor patella with index finger, while fingers of right hand run along groove beside patella first on one side then the other. A positive sign if there is a bulge along the groove on the side not being compressed- this indicates a small effusion.

- Slide patella sideways across underlying femoral condyles to examine for patellofemoral lesions.

3.) Move

- Test joint movement

• Flexion- possible to 135 degrees
• Extension- normal to 5 degrees
• To test collateral ligaments- knee is slightly flexed while holding leg, then test lateral and medial movements (more than 5-10 degrees- abnormal)
• Cruciate ligaments- Examiner sits on patient's foot to steady it, knee flexed to 90 degrees, grasp tibia and move leg anteriorly and posteriorly at knee joint. (normal movement 5-10 degrees)
• Lachman test- knee flex 20-30 degrees, grasp femur, steady knee with other hand and give it a quick forward tug. (abnormal if knee fails to stop with a thud)
• Mc Murrays test- detecting meniscal tears. Bend hip and knee to 90 degrees and grip heel while pressing medial then lateral cartilage. Internally and externally rotate tibia
• Apley's grinding test-patient lying prone, flex knee 90 degrees, examiner kneel lightly on thigh of patient, while pressing foot rotate leg backwards and forwards (test positive if pain or clicking)

Source,

• N.J. Talley and S. O'Connor, Clinical examination, A systematic guide to physical diagnosis 6th Edition, Elsevier, 2010
• Epstein, Perkin, Cookson and de Bono, Pocket guide to clinical examination, 3rd edition, Mosby, 2004

'He who cures a disease may be the skillfullest, but he that prevents it is the safest physician.- Thomas Fuller'