Knee Exam

Look

 

Shoes

Walking aids

 

Front

 

Knee alignment 

- physiological valgus

 

Patellar rotation 

- squinting (inwards, increased PFA) 

- grasshopper eyes (high and lateral)

 

Swelling

Quads Wasting

Scars

 

Knee effusion

 

Side

 

Knee attitude

- flexion

- recurvatum

- push knees back

 

Knee FFD Standing

 

Step foot forward and bear weight

- examine arch

 

Scars

 

Behind

 

Hindfoot valgus

Swelling popliteal fossa

Wasting of hamstrings or calf

Level popliteal creases

 

Other Side

 

Knee attitude

- flexion

- recurvatum

- push knees back

 

Step foot forward

 

Scars

 

Gait

 

Rigid / Stiff

- decreased flexion / extension range

 

Antalgic

 

Weak knee

- back knee gait

 

Medial or lateral thrust

- valgus or varus moment about the knee

 

Foot progression angle

 

Sit on Edge of Bed

 

Patella tracking

- crepitus

 

J tracking

- patellar sharply deviates laterally in terminal extension

- or travel laterally until jumps into trochlea at midrange of flexion

 

Supine

 

Look 

- quads wasting

- alignment

- scars

 

Effusion

- swipe, ballot, tap

 

Range

- FFD / Recurvatum / lift foot in air

- active extension / quads lag

- range of flexion bilaterally

 

Knee FFD LyingKnee FFD Fixed

 

FFD

- effusion

- entrapped meniscus

- ACL stump

- loose body

 

Feel

 

Flat

- Extensor mechanism

- patella

- tibial tuberosity

 

Flexed

- Joint lines, MCL, LCL

- tibial and femoral condyles

- popliteal fossa

 

Palpate distal femur for osteochondromas

 

Examine Ligaments

 

Collaterals

 

Test at 0 and 30o

- if loose at 0, loss of secondary stabilisers

 

Grading

1+   Surfaces separate 5mm or less

2+   5 - 10 mm

3+   10 mm or more

 

ACL / PCL

 

Lachmann's

- 85% sensitive awake

- 100% asleep

 

Check loss of tibial step off

- posterior sag

- MTP normally 1 cm anterior to MFC

 

Quadriceps active

- knee at 90o

- stabilise foot & ask to slide foot down bed

- N < 1mm / PCL > 3mm

 

Anterior / Posterior drawer

- restore tibial step off

 

Posterolateral drawer

- 30o IR

- tightens PLC

 

Posteromedial drawer

- 15o ER

- tightens PMC

 

Pivot Shift

- valgus stress with IR + axial compression

- knee moved from extension to flexion

- in chronic ACL deficiency, the LTC is subluxed anteriorly

- at 30o it reduces backwards

- this is when ITB passes behind axis of rotation and becomes flexor

- grade pivot glide / 1 / 2 / 3

 

Must have 4 things

- MCL to pivot about

- intact ITB

- no FFD

- ability to glide i.e. no meniscal pathology

 

PCL / Posterolateral Corner (PLC)

 

External rotation / Recurvatum

- hold big toe and assess PLC

- knee moves into recurvatum, tibia externally rotates & subtle varus

- indicates PCL + PLC + LCL

 

Reverse pivot shift 

- with valgus and ER

- flexion to extension

- in flexion, the LTP is posteriorly subluxed

- ITB become extensor

- reduces as extend

- must compare with other side

- present in 30% normal population especially ligamentous lax

 

Dial test / Prone

- measure thigh foot angle

- examiner holds knees together

- increase at 30o only  - PLC

- increases at 30 then again at 90 - PLC + PCL

- isolated PCL - no increase

- >10o compared with normal side

 

Meniscus

 

McMurray

- Flexion to extension

- Full IR - LM

- Full ER - MM

- i.e. test meniscus heel is pointing towards

- positive test is palpable / audible thud, snap, click

 

Squat test

- feet IR and ER

 

4Cs

 

Concealed / popliteal fossa

 

Cephalad / Hip

- rotation in flexion

- adduction / abduction in extension

 

Circulation

 

Collagen