Knee Special Tests

On this page i will present to you how to examine the knee. There are many other test as well as variations of these below. Bottom line, we can analyse condition of ligaments in the knee joint very well by these special test and determine next steps in rehabilitation or prevention.

Anterior Drawer Test

Steps

• Patient is lying supine with his/her hip flexed 45 degrees & knee flexed 90 degrees
• Examiner sits on the patient's foot & grasps the tibia just below the joint line
• Examiner's thumbs are placed along the joint line on either side of the patellar tendon & the index fingers are used to palpate the hamstring tendons
• Examiner ensures that the patient is relaxed, esp. the hamstring tendons
• Examiner draws the tibia straight forward (no rotation)

Positive Test

Increased anterior tibial translation, pain

Positive Test Implications

ACL tear (mainly the anteromedial bundle because the posterolateral bundle is basically laxed in this position)

Posterior Drawer Test

Steps

• Patient is lying supine with his/her hip flexed to 45 degrees & knee flexed to 90 degrees
• Examiner sits on the patient's foot & grasps the tibia just below the joint line
• Examiner's thumbs are placed along the joint line on either side of the patellar tendon
• Examiner ensures that the patient is relaxed, esp. the quadricepsExaminer pushes the tibia posteriorly

Positive Test

Increased posterior tibial translation, pain

Positive Test Implications

PCL tear

Valgus Stress Test (full extension)

Steps

• Patient is supine with the involved leg close to the edge of the table and the knee in full extension
• Examiner supports the medial portion of the distal tibia with one hand while the other hand grasps the knee along the lateral joint line
• Examiner applies a medial (valgus) force to the knee & the distal tibia is moved laterally while the knee is in complete extension

Positive Test

Increased laxity, pain, and guarding

Positive Test Implications

Injury to the MCL, medial joint capsule; probable ACL/PCL involvement if there is no endpoint

Varus Stress Test (full extension)

Steps

• Patient is supine with the involved leg close to the edge of the table and the knee is in full extension
• Examiner supports the lateral portion of the distal tibia with one hand while the other hand grasps the knee along the medial joint line
• Examiner applies a lateral (varus) force to the knee & the distal tibia is moved medially while the knee is in complete extension

Positive Test

Increased laxity, pain, and guarding

Positive Test Implications

Injury to the LCL, lateral joint capsule, & arcuate ligament; probable PCL (& maybe ACL) involvement if there is no endpoint

Lachman's Test

Steps

• Patient is supine with his/her knee passively flexed to approximately 20 degrees & hands crossed across his/her chest
• Examiner's thumb of the same–side hand as the knee to be examined is placed at the anterior medial tibial plateau/joint line, while digits 2–5 are positioned posterior, slighty distal to the popliteal fossa
• Examiner's contralateral hand is placed laterally around the distal femur, just proximal to the patella with the thumb anterior & the digits 2–5 are positioned posteriorly
• Examiner sets the tibia by pushing posterior (to make sure the PCL is in tact)
• Examiner provides an anterior force to the tibia while applying posterior pressure to the femur; repeats the process 2–3 times

Positive Test

Increased anterior tibial translation, pain

Positive Test Implications

ACL tear (primary posterolateral bundle but also the anteromedial bundle)

Lateral Pivot Shift Test (ALRI)

Steps

• Patient is supine with his/her hip passively flexed to 30–45 degrees and slightly abducted
• Examiner grasps the distal lower leg and/or ankle & maintains ~20 degrees of tibial internal rotation
• While maintaining internal rotation, examiner applies a valgus force to the knee while slowly flexing & extending

Positive Test

A palpable "clunk" occurs as the tibia's position on the femur reduces as the leg is flexed between 30–40 degrees & anteriorly subluxes during extension

Positive Test Implications

Sprain of the lateral joint capsule, ACL, and LCL(int. rotation) (plus other possible lateral structures)

McMurry's Test

Steps

• Patient is supine with examiner stands lateral & distal to the involved knee with one hand supporting the lower leg
• Examiner positions thumb & index finger of the opposite hand in the anteromedial & anterolateral joint lines on either side of the patellar tendon
• Examiner keeps the tibia in the neutral position, applies a valgus stress through knee flexion & varus stress through knee extension
• Examiner internally rotates the tibia & applies a valgus stress through knee flexion & a varus stress through knee extension
• Examiner externally rotates the tibia & applies a valgus stress through knee flexion & a varus stress through knee extension

Positive Test

Popping, clicking, or locking of the knee; pain from within the joint

Positive Test Implications

Possible meniscus tear

Apley's Compression Test

Steps

• Patient is prone with his/her knee flexed to 90 degrees
• Examiner applies pressure to the plantar aspect of the heel, applying an axial load to the tibia while simultaneously internally & externally rotating the tibia

Positive Test

Pain; possible clicking

Positive Test Implications

Possible meniscus tear

Patellar Apprehension Test

Steps

• Patient lies supine with his/her quadriceps fully relaxed
• Examiner attempts to move the patient's patella laterally as far as possible with the patient's legs fully extended
• Examiner flexes the knee ~ 30 degrees & attempts to move the patient's patella laterally as far as possible

Positive Test

Patient forcefully contracts quadriceps and/or demonstrates apprehension, c/o pain

Positive Test Implications

Patellar subluxation/medial patellar retinaculum sprain