Assessing the Lower Extremities in the Geriatric Patient

Mark E. Williams, MD

Disclosures

November 08, 2010

In This Article

Assessment of the Knee in the Geriatric Patient

General Evaluation of the Knee

It is normal for both the ankles and the knees to touch. Being knock-kneed (knees touch but ankles do not) involves a valgus deformity of the knee. Bow-leggedness (ankles touch but knees do not) is a varus deformity of the knee. If the knees curve backward in the lateral dimension, there is a genu recurvatum deformity. Osteoarthritis will produce bony enlargement, which is sometimes magnified by coincident quadricep muscle atrophy. Look for scars that indicate previous knee surgery.

Check knee range of motion. Observe passive knee range of motion by gently flexing and extending the knee with the patient sitting or supine. Decreased range of motion suggests degenerative joint disease. Increased lateral movement suggests damaged ligaments.

Check for crepitus. Check for crepitus in the knee joint by listening for the crunching, popping sound (or feeling) on joint movement. Finding no crepitus is normal. If crepitus is present, it suggests degenerative joint disease. The location defines the affected compartment, so that anterior, lateral, or medial crepitus suggests knee degenerative joint disease in those respective locations. Crepitus on extension suggests patellofemoral syndrome.

Check for effusion. Now search for knee effusion. Feel for a spongy movement of the patella and look for a bulge between the patella and the condyles. If there is any spongy downward movement of the patella when the leg is fully extended, then an effusion is present. In addition, you can milk the fluid from the medial side with your forefingers and middle fingers and then push with your thumbs from the lateral side just below the patella. Seeing a medial bulge (bulge sign) suggests effusion.

Check the tibial and femoral condyles positions. Tibial condyles displaced posteriorly to the femoral condyles suggest a prior posterior cruciate ligament tear. Tibial condyles displaced anteriorly to the femoral condyles suggest a prior anterior cruciate ligament tear.

Anterior Knee Pain

Check for bony deformity.

Check for effusion (vide supra). If present, patellar effusion will present as spongy ballottement, bulging of the joint, or a fluid wave. Check for tenderness and swelling over the quadriceps muscles. The presence of pain suggests quadriceps rupture or strain.

Check for patellar tenderness. Doughy swelling above the patella suggests suprapatellar bursitis (housemaid's knee). Swelling and tenderness on the patella suggest prepatellar bursitis (roofer's knee), usually brought on by constant kneeling. Marked tenderness and swelling over the patella suggest patellar fracture. Tenderness below the patella without swelling suggests tendonitis (jumper's knee). Swelling and tenderness below the patella suggest infrapatellar bursitis (pastor's knee).

Patellofemoral syndrome. Look for quadriceps atrophy, especially the vastus obliquus medialis. Also feel for tenderness behind the patella with palpation. Perform the patellar inhibition test. Stabilize the patella with your thumb and forefinger, and then gently try to push it toward the feet. Have the patient contract the quadriceps to move the patella upward. Pain and relaxation of the quadriceps is a positive test. Now move the patella medially and laterally with knee flexed to 30 degrees. Increased lateral mobility is a positive apprehension test. Voluntary contraction of the quadriceps when moving the patella laterally is also a positive test. Check for lateral patellar displacement with extension that resolves with flexion.

Pain Behind the Knee

Search for a popliteal mass. A nontender area of bogginess suggests a Baker's cyst. Feeling a pulsatile mass suggests popliteal artery aneurysm. Feeling a tender mass in the popliteal fossa suggests bursitis.

Look for focal or diffuse tenderness in the popliteal fossa. Focal tenderness in the medial popliteal fossa without a mass suggests a hamstring muscle strain. Diffuse tenderness and swelling suggest a ruptured Baker's cyst or deep venous thrombosis.

Medial Knee Pain

Palpate for tenderness. Check for an anatomic deformity and palpate the site of tenderness. Pain behind the knee suggests a hamstring tear. Exquisite tenderness medial and inferior to the tibial plateau suggests anserine bursitis. Tenderness midway between the femur and the tibia suggests medial collateral ligament damage. Tenderness anterior to the condyles suggests a medial meniscus tear.

Check for joint laxity. Now test for joint laxity with lateral movement. The degree of laxity defines the extent of medial collateral ligament tear. Pain in the lateral knee with this movement suggests lateral meniscus tear (Bohler's sign).

Check for meniscus tear. Employ McMurray's maneuver; with the patient supine, passively flex the knee until the heel hits the buttock. Rotate foot laterally and then extend the knee. A loud click over the lateral knee suggests a medial meniscus tear. Also check Apley's compression test. With the patient prone and the knee flexed to 90° (perpendicular to the examining table), push down and gently twist the foot. Pain or crepitus is a positive test. Payr's test is also useful. With the patient sitting cross-legged, push on the painful knee. Medial knee pain is a positive test.

Lateral Knee Pain

Check for anatomic deformity.

Palpate for tenderness. Palpate the site of tenderness with the knee straight and then flexed to 90°. Tenderness over the fibular head suggests fibular fracture. Tenderness between the femur and fibular head suggests lateral collateral ligament sprain. Tenderness just anterior to the femoral condyles suggests lateral meniscus tear. Tenderness over the lateral tibial condyle radiating over the lateral thigh suggests iliotibial band syndrome.

Check for joint laxity. Check for joint laxity by holding the knee and moving the foot medially. The amount of pain and the degree of laxity define the extent of lateral collateral ligament tear. Pain in the medial knee suggests medial meniscus tear.

Check for Ober's sign. With the patient supine, passively flex and abduct the leg, and then gently let go and have the patient maintain the leg position. Pain in the anterior thigh (positive Ober's sign) suggests tensor fascia lata syndrome. Pain in the lateral knee suggests iliotibial band syndrome.

Look for a meniscus tear. See "Check for Meniscus Tear" under "Medial Knee Pain," above.

A Knee That Gives Way

Check the basic landmarks for anatomic deformity.

Examine the anterior cruciate ligament. Perform the drawer test by pulling out on the tibia to see how far the tibia slides anteriorly over the femur. Sensing a sharp stopping point of movement is normal. Noting greater than 2 mm of movement and/or a boggy stopping point suggests a tear. Rotational movement (where only 1 condyle moves) suggests tear of the corresponding collateral ligament.

Now check the drawer test with the patient prone. Lachman sign is basically a drawer sign with the posterior knee supported to relax the hamstrings.

Check the Galway-MacIntosh test. With the patient supine, passively flex the hip with the knee extended. Anterior movement of the tibia more than 2 mm suggests a tear. Confirm by applying valgus force to the leg while passively flexing the knee. A sharp reduction of the subluxation at 20°-40° flexion is a positive test.

Check the posterior cruciate ligament. Perform the drawer test to see how far the tibia slides posteriorly over the femur. A sharp stopping point of movement is normal. Greater than 2 mm of movement and/or a boggy stopping point suggests a tear. Rotational movement, where only 1 condyle moves, suggests a tear of the corresponding collateral ligament.

Check for posterior sag by supporting the distal femur with pillows and see whether the tibia is posteriorly displaced. With the patient supine and knee flexed at 90°, push posteriorly on the tibial plateau. Posterior movement suggests a tear.

Check for Godfrey's sign. With the patient supine, passively flex at the hip with the knee in full extension. Pull up on the distal foot to 90° with varus and external rotation. Posterior movement of the tibia suggests a tear.

Check the collateral ligaments. Check for joint laxity with lateral movement. The degree of laxity defines the extent of medial collateral ligament tear. Hold the knee and move the foot medially. The amount of pain and the degree of laxity define the extent of lateral collateral ligament tear.

Check for meniscal tear. See "Check for Meniscus Tear" under "Medial Knee Pain," above

Palpate the lateral knee. Tenderness suggests proximal fibular fracture.

Additional Knee Assessment Pearls

  • A decrease in knee pain by forward flexion and lateral rotation of the foot suggests medial meniscus injury (Bragard's sign).

  • Increased anterior-posterior movement of the tibia over the femur with a click or pain suggests damage to the anterior or posterior cruciate ligaments (drawer or Rocher's sign).

  • With the patient sitting cross-legged, exert downward pressure along the medial aspect of the knee. Medial knee pain indicates a posterior horn lesion of the medial meniscus.

  • Anesthesia in the popliteal fossa suggests neurosyphilis (Bekhterev's sign).

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