Knee Examination

Original Editor - Rachael Lowe

Top Contributors - Admin, Naomi O'Reilly, Rachael Lowe, Laura Ritchie, Kim Jackson, Ben Kasehagen, 127.0.0.1, Tarina van der Stockt, Jess Bell, Evan Thomas, Michelle Lee, Kai A. Sigel, Vidya Acharya, Rucha Gadgil, Wanda van Niekerk and Samuel Winter

Subjective (Patient Intake)

Patient Intake

• History of present condition (HPC) (Was there trauma or was it insidious onset? Mechanism of Injury?)
  

Special Questions (Region‐specific historical examination)

• Any backhip or leg pain? (Is pain in a dermatomal region - pain in the knee can be referred from the back)
• Is there hip pain? (Knee pain can be referred from the hip)
• Did the patient hear a pop/click at time of injury?
• Does the knee give way? (instability/rupture of ligaments)
• Did the knee swell? How quickly? Where is the swelling? (Intra articular/ extra articular; immediate swelling usually indicates trauma within the knee such as ligament damage)
• Was there bruising? (Immediate bruising indicates significant trauma
• Cough/sneeze cause pain?</span>
• Does the patient experiencing locking (may indicate a bucket handle meniscal tear).
• Age – The following conditions are not exclusive to these age groups but a higher prevalence is noted in these populations (elderly – OA?, young – osgoods schlatters, middle aged- meniscal).
• Type of shoes ( wear patterns/age of shoes/proper design)

Additional Information

• Past Medical History (PMH) (Pre-existing medical conditions)
• Drug history (DH) (Any relevant medications?)
• Social History (SH) (Work/sports/hobbies affected?)

Investigations

• Radiological Considerations  - any previous X-Rays or scans
  
• Other investigations - any recent blood tests

Red Flags

These are the special questions which may indicate that something more sinister may be going on. If you suspect that the problem is not musculoskeletal and/or something sinister may be going on patients should be referred immediately back to their doctor with your concerns noted. 

• Bilateral pins and needles or numbness in the LL.
• Problems with bowel and bladder function where the patient is unable to feel themselves going to the toilet.
• Incontinence.
• Paraesthesia in the groin region.
• Loss of pulses in the LL (Vascular compromise).
• Obvious deformity.

If nothing sinister but the symptoms are more severe than you might expect ask a seniors advice on whether and A&E referral is more appropriate. Mechanism of Injury is important here, what force was exerted through the leg? Was it enough for a tibia/femur fracture? Loss of pulses in the foot may indicate vascular compromise.

Clinical reasoning - what does the history tell you?

Knowing the history gives clues as to the structures affected. Mechanism of injury is extremely important. If you can work out the force of the injury this gives you clues on likely stretched/ damaged structures (Valgus force may indicate an MCL sprain, varus force may indicate an LCL sprain, foot planted and twisted may indicate an ACL sprain/rupture).

Make sure you rule out the back and hip unless there is a clear mechanism of injury as the knee can be a referred site of pain for both these areas. Immediate swelling and bruising usually indicates significant trauma and may require X-Ray to rule out tibial plateau fractures, bone bruises or an MRI to investigate integrity of the ligaments.

Go into your objective examination with a working hypothesis.  Use your physical examination to identify dysfunction and special tests to prove or disprove your hypothesis.

Mechnisms of Injury

ACL strain/ tear

• H/o valgus or hyperextension force to knee if contact injury.
• Sharp change in direction in non contact injury.
• H/o audible ‘pop’
• H/o a quick stop, landing with knee fully extended
• Severe effusion within 4-6 hours.
  

ITB Syndrome

• H/o increased training (ie running distance; intensity/distance/frequency)
• C/o lateral knee pain
  

MCL strain/ Tear

• Valgus force to knee in contact/non contact injury.
• C/o medial knee pain.
  

LCL strain/Tear

• Varus force to knee in contact/non contact injury.
• C/o lateral knee pain.

Chronic patella subluxation

• C/o giving way/instability/pain.
• C/o catching of the patella
• Localised pain on the medial aspect of patella.
• Restricted function/ sports due to apprehension of instability.
  

Patella dislocation

• H/o rotation or valgus force to knee.
• Patient may describe seeing dislocation that ‘popped back’ spontaneously or needed reduction by medical staff.
• Increased prevalence in females.
• C/o medial patella shift of knee.
  

Patella tendinopathy (Jumper’s knee)

• H/o kicking, running, climbing.
• Symptoms localised to the patella tendon.

Osgood-Schlatters Syndrome

• Children/Puberty.
• Pain on tibial tuberosity.

Objective

The objective examination gives you quantifiable measures to rule out what structures are involved and to reassess after treatment to determine improvement/deterioration.

General Observation

• Posture
• Movement Patterns

Functional Tests

• Small knee bend
• Sit to stand
• Squat
• Jump
• Hop
• Run
  

Inspection & Palpation

• Inspection - effusion, poor alignment, muscle wasting
• Palpation - MCL, LCL, joint line, patella, retinaculae, patellar tendon, hamstrings tendons, popliteus.

Neurologic Assessment

If neurological defecits or referral from lumbar spine are suspected you should perform a neurological assessemnt:

1. Reflexes
2. Dermatomes
3. Myotomes

Movement Testing

• AROM, PROM, and Overpressure
• Muscle Strength
  
• Clear hip and ankle with full AROM + overpressure
• If lumbar spine suspected add passive intevertebral mobilisations (PA spinous processes, PA transverse proceses).

Special Tests

ACL

• Lachmans Test
• Anterior drawer
• Pivot-Shift
• Slocum's Test

PCL

• Sag sign
  
• Posterior Drawer

MCL/LCL

• Valgus stress test

LCL

• Varus stress tests
• Dial Test (postero-lateral corner)

Meniscus

• McMurrays
• Bounce home
• Joint line tenderness
• Apley’s Test
• Ege's Test
• Steinman Test
• Thessaly test

Patellofemoral

• Apprehension
• Grind Test (Clarkes sign)

ITB

• Noble’s compression
• Ober’s Test

Osteochondritis Dissecans

• Wilson’s Test

See a list of knee special tests