The Knee Exam
1. Make sure that both knees are fully exposed. The patient should be in either a gown or shorts. Rolled up pant legs do not provide good exposure!
2. Watch the patient walk. Do they limp or appear to be in pain? When standing, is there evidence of bowing (varus) or knock-kneed (valgus) deformity? There is a predilection for degenerative joint disease to affect the medical aspect of the knee, a common cause of bowing. Varus Knee Deformity, more marked on the left leg. 3. Make note of any scars or asymmetry. Chronic/progressive damage, as in degenerative joint disease, may lead to abnormal contours and appearance. Is there obvious swelling as would occur in an effusion? Redness suggesting inflammation? 4. Is there evidence of atrophy of the quadriceps, hamstring, or calf muscle groups? Knee problems/pain can limit the use of the affected leg, leading to wasting of the muscles.
While both legs have well developed musculature,
the left calf and hamstring are bulkier than the right. 5. Look at the external anatomy, noting structures above and below the knee itself: 1. Patella 2. Patellar tendon 3. Quadriceps/Hamstring/Calf muscles 4. Medial and lateral joint lines. 5. Femur and Tibia 6. Tibial tuberosity
Ballotment (helpful if the effusion is large) 1. Slightly flex the knee which is to be examined.
2. Place one hand on the supra-pateallar pouch, which is above the patella and communicates with the joint space. Gently push down and towards the patella, forcing any fluid to accumulate in the central part of the joint.
3. Gently push down on the patella with your thumb.
4. If there is a sizable effusion, the patella will feel as if it's floating and "bounce" back up when pushed down.