Examination

• Normal neurovascular function
• Identify if fractures or dislocations are present
• Demonstrate that the knee is not grossly unstable (particularly in full extension)
• Demonstrate an intact quadriceps mechanism

• If a mechanism or pattern:
  • When did it happen?
  • What happened exactly?  Try to understand the mechanism and forces involved (if present)
    • Position of the foot and knee
    • Direction of the force
  • What symptoms initially?
    • Degree and location of pain
    • Describe pain – sharp / superficial / deep / ache / burning etc
    • How quickly swelling develops – severe swelling within 1-2 hours, versus slowly developing swelling
    • Were they able to continue?
    • Ability to WB, both at the time and now
    • What aggravates and what eases?
    • Giving way – due to pain or just gave way
    • Locking
    • Clicks, cracks or pops
    • Sensations of patella moving out of place (or visualisation)
  • What symptoms now?
    • Have the symptoms changed? Better / Worse? Location?
• If no mechanism
  • How long has it been there?
  • Is there anything that they believe may have contributed to the development of the problem? Recent activity / inactivity
  • What symptoms are present?
    • Pain
    • Clicking / catching / locking / giving way
  • Are they there all the time?
• What treatment has been sought so far?
  • Assessment
  • Investigations
    • If imaging, do they have it with them?
    • If not, can we view it?
      • Private providers use online applications
      • If in another public hospital in Victoria, then can use the “Synapse Mix” service to get the images temporarily put on local network diagnostic imaging servers.
  • What management has been undertaken? Has it been effective
    • Splinting
    • Ice
    • Medications
• History of problems in that area before
  • When?
  • How was it managed?
    • Assessment undertaken?
    • Investigations
    • Medications
  • Any ongoing problems?
• Any associated symptoms (if a non mechanical cause or if at all suspicious)
  • Recent illness / fevers / sweats
  • Recent overseas / long haul travel / immobilisation (eg for suspected DVT)
  • Loss of appetite / loss of weight, etc
• If has a wound
  • Tetanus status
• If potentially needing procedural sedation or surgery (and consider this for anyone you are contemplating an x-ray for)
  • Fasting status (and tell them not to eat and drink until you tell them it is ok to do so)

General Considerations

• In an acute injury:
  • Often everything hurts
  • Weightbearing is usually difficult
  • Active and passive movement is often painful
  • The patient will probably use extensive muscle guarding to prevent further pain
• This makes assessment difficult and patients should be referred on for followup assessment and treatment advice
• With assessment of the knee, perhaps more so than any other joint, it is important for the patient to be completely relaxed or the examination will not be accurate.
• Handling is crucial
• If no significant laxity is demonstrable initially but you are still suspicious of injury to ACL (eg “pop” or “crack”, giving way) or menisci (locking) arrange appropriate followup (physiotherapy or sports physician) for reassessment once the acute symptoms have subsided.
• If there is substantial ligamentous laxity, particularly in an extended knee or with a high force mechanism (eg struck by car or kicked by horse) orthopaedic review is vital

Examination

• OBS – HR, BP, TEMP (IF INDICATED)
• Distal Neurovascular function
  • Colour, movement, warmth, sensation
  • Capillary return
  • Dorsalis Pedis, Posterior Tibial pulses
  • Common Peroneal / Superficial Peroneal / Tibial Nerve function
• Swelling
  • Effusion (watery fluid able to be moved between pouches; slow onset)
  • Haemarthrosis (boggy, bloody swelling; rapid onset = usually indicates trauma to ACL, PCL, Menisci, PFJ dislocation or #)
• Color – is it red?
• Any Bruising / deformity

• Avility to actively Straight Leg Raise
• Ability to WB
• Squat – Bilateral and Unilateral
• Duckwalk (if able to deep squat without significant pain)

• Range of motion (Active vs Passive)
• Flexion / Extension
• Squat – Bilateral / Unilateral
• Extension / Abduction
• Extension / Adduction

• Lateral Stability Tests
  • Valgus Stress Test 0 and 30 degrees
  • Varus Stress Test 0 and 30 degrees

• AP and PA Stability Tests (Cruciate Ligaments)
  • Lachman’s Test
  • Pivot Shift Test
  • Anterior Drawer Test
  • Posterior Sag Test
  • Posterior Drawer Test
  • Reverse Lachman’s Test

• Meniscal / Internal Derangement Tests
  • McMurray’s Test
  • Apley’s Grind Test

• Patellofemoral Joint / Quadriceps Complex
  • Straight Leg Raise
  • Apprehension Test
  • Glides – Medial / Lateral / Superior / Inferior
  • Compression

• Muscle Length Tests
  • Ober’s Test
  • Hamstrings
  • Quadriceps

• Bony
  • Femur down to knee
  • Fibular from fibular head down to ankle
  • Tibia from knee down to ankle, including tibial tubercle
  • Patella
• Palpate
  • Medial joint line posterior to anterior
  • Medial Collateral Ligament
  • Medial Retinaculum
  • Pes Anserenus
  • Lateral joint line posterior to anterior
  • Lateral Collateral Ligament
  • Lateral Retinaculum
  • ITB
  • Hamstrings
  • Patellofemoral Joint margins
  • Quadriceps Tendon
  • Patellar Tendon
  • Posterolateral knee

• X-ray
  • Ottawa Knee Rule
    • A knee x-ray is only needed if there are ANY of the following
      • Aged > 55 years old
      • Inability to flex to 90 degrees
      • Isolated tenderness of the patella
      • Tenderness of the fibular head
      • Inability to weight bear for 4 steps (regardless of limp) BOTH at the time of injury AND on assessment
• CT
  • If suspicion of fracture but not proved on plain films (eg if a lipohaemarthrosis but no identifiable fracture)
  • To quantify a fracture in order to plan for theatre
• MRI
  • Only if directed after discussion with Radiology / Orthopaedics
    • Grossly unstable knee
• Ultrasound
  • For ambiguous quads tendon rupture (if obvious, discuss with Orthopaedics)

• Stabilise the patients leg to control hip rotation and knee flexion
• Apply a valgus (abduction) force to the knee in both full extension and 30 degrees of flexion

• Pain on the medial side of the knee indicates pathology on attempted opening up of the medial joint space.
• Laxity of movement indicates more significant damage:
  • Grade I MCL sprain = pain on testing without laxity
  • Grade II = pain with mild laxity
  • Grade III = pain with moderate to significant laxity
• Laxity only in flexion tends to indicate isolated MCL damage, however if there is laxity in extension as well, this might indicate damage to other structures such as the ACL (the knee is most stable in extension, so if it is now unstable, there is usually more than the MCL damaged)
• Pain on the lateral side of the knee indicates pathology on closing down the lateral joint space = potential lateral meniscal damage or other internal derangement

• Stabilise the patients leg to control hip rotation and knee flexion
• Apply a varus (adduction) force to the knee in both full extension and 30 degrees of flexion

• Pain on the lateral side of the knee indicates pathology on opening up of the lateral joint space.
• Laxity of movement indicates more significant damage:
  • Grade I LCL sprain = pain on testing without laxity
  • Grade II = pain with mild laxity
  • Grade III = pain with moderate to significant laxity
• Laxity only in flexion tends to indicate isolated LCL damage, however if there is laxity in extension as well, this might indicate damage to other structures such as the ACL (the knee is most stable in extension, so if it is now unstable, there is usually more than the LCL damaged), PCL or posterolateral corner
• Pain on the medial side of the knee indicates pathology on closing down the medial joint space = potential medial meniscal damage

• With the knee supported in slight flexion, use one hand to stabilise the thigh and the other on the posterior aspect of the proximal tibia
• Pull tibia forwards
• Increased anterior movement and lack of firm end feel suggests ACL rupture

• Increased anterior translation and loss of normal endfeel may indicate ACL rupture

• Knee flexed to approximately 90 degrees and stabilise the leg (sit on the foot)
• Using both hands on the posterior aspect of the tibia, draw the tibia anteriorly.

• Increased anterior translation and loss of normal endfeel may indicate ACL rupture
• This test is often difficult in an acutely injured knee and Lachman’s test is significantly more specific and sensitive

• A positive pivot shift test may indicate ACL rupture
• This test is difficult to perform in an acutely painful knee
• Much of the data on test sensitivity and specificity is based on work done pre-operatively on anaesthetised patients

• With the knee supported in slight flexion, use one hand to stabilise the thigh and the other on the anterior aspect of the proximal tibia
• Push the tibia posteriorly

• Increased movement and lack of firm end feel suggests PCL rupture

• Knee flexed to approximately 90 degrees and stabilise the leg (sit on the foot)
• Using both hands on the anterior aspect of the tibia, push the tibia posteriorly.

• Increased posterior translation and loss of normal endfeel may indicate PCL rupture
• This test is often difficult in an acutely injured knee
• Internal derangement may give a false negative
• Pain alone does not necessarily indicate damage to the PCL

• With the patient in supine and the knees bent to 90 degrees, place the palm of your hand on the tibia, with the MCP joints at the level of the tibial tubercle
• If there is posterior sag that is not obviously evident on inspection, this may be a more easier way to detect (the MCPs are particularly sensitive to extension)

• In a positive test, the MCPs will be more extended than usual, indicating a posterior sag of the tibia and likely PCL injury

• Begin with knee fully flexed
• Externally rotate the tibia and extend the knee, applying a valgus force as you extend
• Repeat with internal rotation / varus

• Reproducible pain +/- clicking should be worse with compression for meniscal injury / internal derangement

• Position patient in prone
• Bend knee to 90 degrees
• Apply a downward (compressive) force through the foot as you rotate the knee medially and laterally
• Repeat with upwards (distractive) force
• In more extension, this will focus more on the posterior horn and in more flexion, the anterior horn

• Reproducible pain +/- clicking should be worse with compression for meniscal injury / internal derangement

• Attempt to sublux the fibular head anteriorly or posteriorly
• This can be performed in supine or sidelying

• If increased movement, pain with assessment or subluxation is possible, this indicates laxity at this joint

• Inability to straight leg raise usually indicates disruption of the quadriceps mechanism, although pain may make this difficult sometimes
• If the patient is unable to straight leg raise despite prompting, it may be necessary to test the quadriceps in a different position, such as sitting over the edge of the bed and attempting to actively extend the knee.

• With knee in full extension, attempt to pull the patella laterally
• Can also be tested in knee flexion (30 degrees) but retropatellar force from passive quads tension makes this position more difficult to create a lateral glide naturally
• Often easier to see change with knee extended as opposed to flexed

• The test is positive where there is increased lateral excursion, apprehension sign (patient reflexively contracts quadriceps or grabs your arm to prevent patella dislocating), subjective feeling of instability with pain
• Pain alone does not make a positive test

• Attempt to glide the patella medially, laterally, superiorly and inferiorly +/- compression through the PFJ

• Pain with compression and glides usually indicates PFJ dysfunction

• Have the patient positioned either lying prone or kneeling on the edge of the chair
• Squeeze the calf muscle

• If the calf / achilles complex is intact, then the foot should actively plantarflex as the calf is squeezed
• If the ankle does not plantarflex, this may indicate loss of integrity of the calf / achilles complex