Knee Examination Flashcards
What 3 clinical signs are you assessing for during ‘general inspection’?
- Body habitus
- Scars
- Muscle wasting
What 8 clinical signs are you looking for when assessing for during ‘anterior’ closer inspection of the knee?
- Scars
- Valgus deformity of the knee
- Varus deformity of the knee
- Bruising
- Quadriceps wasting
- Patella position
- Swelling
- Psoriasis plaques
What may bruising of the knee indicate?
- Recent trauma
- Spontaneous haemarthrosis
In which patients do you see spontaneous haemarthrosis?
Those on anticoagulants or with clotting disorders e.g. haemophilia
What can asymmetry of size of knee joint suggest?
Unilateral swelling e.g. effusion, inflammatory arthropathy, septic arthritis, haemarthrosis
Where do psoriasis plaques typically present?
Over extensor surfaces
What MSK condition are those with psoriasis at increased risk of?
Psoriatic arthritis
Where is the patella normally located? What can deviation indicate?
Patella is normally located over the centre of the knee joint and any deviation may indicate patellar dislocation or subluxation (partial dislocation)
What can quadriceps wasting indicate?
Any asymmetry in bulk of quadriceps muscle may be due to disuse atrophy or a LMN lesion
What 2 clinical signs are you looking for when assessing for during ‘lateral’ closer inspection of the knee?
- Extension abnormalities e.g. knee hyperextension
- Flexion abnormalities e.g. fixed flexion deformity at the knee joint
What injury can knee hyperextension occur 2ary to?
Cruciate ligament injury
What can fixed flexion deformity at the knee joint suggest the presence of?
Contractures 2ary to previous trauma, inflammatory conditions or neurological disease
What 3 clinical signs are you looking for when assessing for during ‘posterior’ closer inspection of the knee?
- Scars
- Muscle wasting
- Popliteal swellings
What are the 2 main popliteal swellings?
- Baker’s cyst
- Popliteal aneurysm (often pulsatile)
What 6 gait signs are you assessing for as the patient walks to the end of the room and back?
- Gait cycle abnormalities
- Range of movement
- Limping
- Leg length
- Turning
- Height of steps
What is a high-stepping gait associated with?
Foot drop
What can foot drop be caused by?
Peroneal nerve palsy (e.g. trauma, surgery)
After asking the patient to lay down on clinical examination couch with headrest position at 45-degree angle, what do you then do?
Briefly inspect the knee joints once more for abnormalities whilst the patient is lying down
What steps are involved in the ‘look’ portion of the knee examination?
- General inspection: clinical signs, objects & equipment
- Closer inspection: anterior, lateral & posterior
- Gait
- Inspection with patient lying on bed
What steps are involved in the ‘feel’ portion of the knee exam?
- Temperature
- Measurement of quadriceps bulk
- Palpation of extended knee: patella, medial & lateral joint line
- Assessment for joint effusion: patella tap, sweep test
- Palpation of flexed knee: patella, medial & lateral joint lines, tibial tuberosity and head of fibula, popliteal fossa
How do you assess the temperature of the knee joint?
With patient positioned supine on clinical couch, with headrest at 45-degree angle, simultaneously assess and compare knee joint temperature using back of hands.
What does increased temperature of a joint indicate?
Increased temperature of joint, particularly if associated with swelling and tenderness, may indicate septic arthritis, inflammatory arthritis, gout or pseudogout.
Why do we measure quadriceps bulk instead of just looking on inspection?
Wasting will often be apparent on inspection, but subtle wasting may only be detectable by comparative measurement of leg circumference.
How do you measure the circumference of leg in region of quadriceps?
- Place a measuring tape around each leg at a point approx. 20cm above the tibial tuberosity
- Record the circumference of each leg and compare to see if there is a significant difference indicative of quadriceps wasting
Whats steps are involved in palpation of the extended knee?
- Quadriceps tendon
- Patella (medial and lateral borders)
- Patellar tendon
- Medial and lateral joint lines
What is the correct method of palpating the medial and lateral border of the patella?
Stabilise one side of the patella and palpating the other with a fingertip
What can patella tenderness indicate?
- Injury
- Patellofemoral arthritis
What can patellar ligament tenderness suggest?
Tendonitis or rupture
What can tenderness of the medial and lateral joint lines of the knee (including the collateral ligaments) indicate?
- Fracture
- Mensical injury (e.g. meniscal tear)
- Collateral ligament injury (e.g. rupture)
What can tenderness of the quads tendon indicate?
- Injury
- Rupture
What test is used to screen for the presence of a moderate to large knee joint effusion?
Patellar tap
What test is used to screen for the presence of a small knee joint effusion?
Sweep test
Describe the position of the patient in the sweep test
Patient supine with leg relaxed and knee extended
Describe the steps of the sweep test
- Empty the suprapatellar pouch by sliding your left hand down the thigh to the upper border of the patellar
- Stroke the medial side of the knee joint to move any excess fluid across to the lateral side of the joint (and hold hand there)
- Now stroke the lateral side of the knee joint which will cause any excess fluid to move back across to the emptied medial side
What would indicate the presence of a small joint effusion in the sweep test?
appearance of a bulge or ripple on the medial side of the joint indicating an effusion
What steps are involved in palpation of flexed knee?
- Patella (medial and lateral edges)
- Medial and lateral joint lines
- Patella tendon
- Tibial tuberosity
- Head of fibula
- Collateral ligaments
- Popliteal fossa
Are joint lines and the popliteal fossa easier to assess with the knee extended or flexed?
Flexed
When palpating the tibial tuberosity, what are you assessing for?
Evidence of a bony elevation and tenderness
What condition is a bony elevation and tenderness of the tibial tuberosity indicative of?
Osgood-Schlatter disease
What is head of fibula tenderness often associated with?
Fracture
What is Osgood-Schlatter disease?
Inflammation of the patellar ligament at the tibial tuberosity (its insertion point)
How does Osgood-Schlatter disease typically present?
Painful bony elevation over the tibial tuberosity which is worsened with activity
Who does Osgood-Schlatter disease typically affect? What is a risk factor?
Most often affects males between 10-15 y/o
Risk factors: overuse (often due to sports that involve lots of running and jumping)
Describe the method of palpating the popliteal fossa
With thumbs placed on tibial tuberosity, curly your fingers into the popliteal fossa
What are the 2 main types of popliteal fossa pathologies you are palpating for?
- Popliteal cyst (Baker’s cyst)
- Popliteal aneurysm
How does a Baker’s cyst typically present?
- As a fluctuant swelling the popliteal fossa
- Swelling will feel tense when patient’s knee is extended and soft when knee is flexed (Foucher’s sign)
- Cyst may transilluminate with a pen torch
How does a Baker’s cyst change between a flexed and extended knee?
Flexed → soft
Extended → tense
What is Foucher’s sign?
When a palpable cyst is often firm in full knee extension and soft in knee flexion (due to cyst compression)
When should a popliteal aneurysm be considered?
Should be considered if the popliteal pulse is visible and superficially palpable (popliteal pulse is normally only palpable on deep palpation of the popliteal fossa)
What steps are involved in the ‘move’ portion of the knee exam?
- Active movement
- Passive movement
Active vs passive movement?
Active - a movement performed independently by the patient
Passive - a movement of the patient, controlled by the examiner
What is the normal range of ‘active/passive’ knee flexion?
0-140 degrees
Instructions to patient for active knee flexion?
“Move your heel as close to your bottom as you can manage”
What is the normal range of active knee extension?
180 degrees
Instructions to patient for active knee extension?
“Straighten your leg out so that it is flat on the bed”
What should you feel for during passive movement?
Crepitus (osteoarthritis)
How can you assess the patient’s knee for hyperextension?
- 1) On the leg being assessed, hold above the ankle joint and gently lift leg upwards
- 2) Inspect knee joint for evidence of hyperextension, with less than 10 degrees being considered normal
What pathologies can excessive knee hyperextension suggest?
- Integrity of knee joint’s ligament
- Hypermobility
What special tests are involved in a knee exam?
- Cruciate ligament assessment: posterior sag sign, anterior drawer test, posterior drawer test
- Collateral ligament assessment: lateral collateral ligament assessment (varus stress test)
- Medial collateral ligament assessment (valgus stress test)
N.B. McMurray’s test for assessing the menisci is not usually expected in an OSCE station due to danger if performed incorrectly
What is the role of the posterior cruciate ligament?
The posterior cruciate ligament (PCL) is responsible for stabilising the knee joint by preventing backward displacement of the tibia or forward sliding of the femur
Where does the PCL originate/insert?
Originates: lateral edge of the medial femoral condyle
Inserts: posterior region of intercondylar area
Injury to the PCL typically occurs 2ary to which mechanism?
Hyperflexion of the knee joint (e.g. a fall onto a flexed knee)
Where does the ACL originate/insert?
Originate: deep within the notch of the distal femur
Inserts: anterior region of the intercondylar area of the tibia
What is the purpose of the ACL?
Stabilise knee joint by preventing anterior tibial subluxation (i.e. prevent anterior displacement of the tibia relative to the femur)
What mechanism does injury to the ACL typically occur 2ary to?
Rupture typically occurs when a patient lands on a leg and then quickly pivots in the opposite direction resulting in a valgus twisting injury (e.g. in football)
How does rupture of the PCL affect the tibia?
The tibia can sag posteriorly in relation to the femur and this is known as the ‘posterior sag sign’
What is the posterior sag sign?
When the PCL is ruptured and the tibia sags posteriorly in relation to the femur and this is known as the ‘posterior sag sign’
What are the steps involved in screening for the posterior sag sign?
- 1) Make sure patient is relaxed
- 2) Ask them to flex their knee to 90 degrees with their foot placed flat on the bed
- 3) Inspect the lateral aspect of the knee joint for evidence of posterior sag
Why is it important to identify the posterior sag sign before proceeding to the anterior drawer test?
As a PCL tear can result in a false positive anterior sign
How can a posterior sag sign be misinterpreted as a false positive anterior draw test?
- An anterior movement of the tibia will occur during the anterior drawer test due to the tibia moving from a posteriorly subluxed position back to its neutral position
- This relocation of the tibia to its neutral position may be misinterpreted as excessive anterior movement 2ary to ACL laxity or rupture
What is the purpose of the anterior drawer test?
To assess the integrity of the ACL
What are the steps of the anterior drawer test?
- 1) Position the patient supine on the clinical examination couch with their knee flexed to 90 degrees
- 2) Wrap your hands around the proximal tibia with your fingers around the back of the knee joint
- 3) Rest your forearm down the patient’s lower leg to fix its position
- 4) Position your thumbs over the tibial tuberosity
- 5) Ask the patient to keep their legs relaxed as tense hamstrings can mask pathology
- 6) Pull the tibia anteriorly and feel for any anterior movement of the tibia on the femur
What should be observed in a healthy anterior drawer test?
Little or no movement noted
What would be observed in an anterior drawer test if there is ACL laxity or rupture?
Significant movement
What are the steps of a posterior draw test?
- 1) Position the patient supine on the clinical examination couch with their knee flexed to 90 degrees
- 2) Wrap your hands around the proximal tibia with your fingers around the back of the knee joint
- 3) Rest your forearm down the patient’s lower leg to fix its position
- 4) Position your thumbs over the tibial tuberosity
- 5) Ask the patient to keep their legs relaxed as tense hamstrings can mask pathology
- 6) Push the tibia posteriorly and feel for any anterior movement of the tibia on the femur
What would be observed in an anterior drawer test if there is PCL laxity or rupture?
Significant posterior movement
What is an alternative test for assessing ACL laxity/rupture?
Lachman’s test
Which collateral ligament is assessed in the ‘varus stress test’?
Lateral collateral ligement
Which collateral ligament is assessed in the ‘valgus stress test’?
Medial collateral ligament
What does the varus stress test (LCL) involve?
The LCL assessment involves the application of a varus force to assess the integrity of the LCL of the knee joint.
What are the steps of the varus stress test (on the right knee)?
- Extend the patient’s knee fully so the leg is straight
- Hold the patient’s ankle between your right elbow and side
- Position your right palm over the medial aspect of the knee
- Position your left palm a little lower down over the lateral aspect of the lower limb, with your fingers reaching upwards to palpate the lateral knee joint
- Push steadily outward with your right palm whilst pushing inwards with the left palm
- Whilst performing this manoeuvre, palpate the lateral knee joint line with the fingers of your left hand
What should be observed in a healthy varus stress test (LCL)?
No abduction or adduction possible
What would be observed in a varus stress test if there is LCL laxity/rupture?
Your fingers should be able to feel a palpable gap caused by the lateral aspect of the joint opening up 2ary to the varus force being applied
What does the valgus stress test (MCL) involve?
The MCL assessment involves the application of a valgus force to assess the integrity of the MCL of the knee joint.
What are the steps of the valgus stress test (on the right knee)?
- Extend the patient’s knee fully so the leg is straight
- Hold the patient’s ankle between your right elbow and side
- Position your left palm over the lateral aspect of the knee
- Position your right palm a little lower down over the medial aspect of the lower limb, with your fingers reaching upwards to palpate the medial knee joint line
- Push steadily inward with your left hand whilst pushing outwards with the right hand
- Whilst performing this manoeuvre, palpate the medial knee joint line with the fingers of your right hand
What should be observed in a healthy valgus stress test (LCL)?
No abduction or adduction possible
What would be observed in a valgus stress test if there is MCL laxity/rupture?
Your fingers should be able to feel a palpable gap caused by the medial aspect of the joint opening up 2ary to the valgus force being applied
What is the function of the MCL?
Stabilise the knee joint by resisting valgus forces that would push the knee medially
What is the function of the LCL?
Stabilises the knee by resisting varus forces that would push the knee laterally
What mechanism does injury to MCL typically occur 2ary to?
Excessive valgus force when the knee is partially flexed (e.g. a direct blow to the lateral aspect of the knee joint)
What mechanism does injury to LCL typically occur 2ary to?
Excessive varus force (e.g. a direct blow to the medial aspect of the knee joint)
What test is used to assess the menisci?
McMurray’s test
What are the menisci of the knee?
The menisci of the knee are two crescent shaped pads of fibrocartilaginous tissue
What is the function of the menisci of the knee?
to stabilise the knee joint and distribute friction between the femur and tibia
What mechanism does injury to the menisci typically occur 2ary to?
sudden twisting of the knee (e.g. in football) which tears the meniscal tissue
What are typical symptoms of meniscal injury?
Sudden onset pain, a popping sensation, locking and instability of the knee joint
What are 3 further investigations after a knee exam?
- Neurovascular examination of both lower limbs
- Examination of the joints above and below (e.g. ankle and hip)
- Further imaging if indicated (e.g. x-ray and MRI)
