knee examination - young

Look

clues

· walking / mobility aids

· external appliances

· shoes

From front

· stand patient facing you

Deformity

· knee alignment

· physiological valgus

· valgus or varus deformity

· patellar rotation

· squinting patellae

· foot rotation

· symmetrical ER

Skin

· scars

· arthroscopy

· circulatory disturbance

· disuse / denervation

Contours

Swelling

· suprapatellar

· general

Wasting

· quadriceps

· VMO

from lateral side

· turn affected side towards you

Deformity

· knee attitude

· flexion

· recurvatum

· foot position

· equinus

Skin

· scars

Contour

Swelling

· tibial tuberosity

from behind

Deformity

· hindfoot

· physiological valgus

Skin

· circulatory disturbance

· scars

Contour

Swelling

· popliteal fossa

Wasting

· hamstrings

· calf

from front

Leg length

· pelvis level

gait

· walk away

· walk towards briskly

Features

Antalgic

Stiff knee

Back knee

sit on couch

· patellar tilt

· path of patella

· during active and passive range

· J- sign

· patella sharply deviates laterally in terminal extension

supine on couch

Look

Quads

· bulk

· tone

· circumference

Effusion

· wipe

· balottment

· patellar tap

Move

Passive extension

· lift both heels

· fixed flexion deformity

· recurvatum

Active extension

· straight leg raise

· quadriceps lag

Active flexion

· bend both knees

· range of flexion

knee flexed

· extend knee to 80^o

Feel

· sit on foot

· extensor mechanism

· tibial tuberosity

· patellar tendon

· inferior pole of patella

· medial joint line

· tenderness

· lateral joint line

· tenderness

· meniscal cyst

· MCL

· origin

· tendon

· insertion

· LCL

· origin

· tendon

· insertion

Move

· hand on knee

· crepitus

· meniscal cyst

knee extended

Collaterals

Full extension

· valgus stress

· no abnormal movement

· opening of joint

· varus stress

30^o flexion

· valgus stress

· no abnormal movement

· opening of joint

· end point

· grade I, II, III

· if abnormal, compare

· varus stress

Cruciates

Lachmann’s

· 15^o flexion with relaxation

· no abnormal movement

· forward movement of tibia on fibula

· end point

· grade I, II, III

knees flexed

Cruciates

Posterior sag

· bend both knees to 90^o

· palm on front of knee

Anterior drawer

· relax hamstrings

· foot in neutral

· no abnormal movement

· forward movement of tibia on fibula

· perform anterior drawer in rotation if abnormal

· foot in 15^o of ER

· medial structures tightened

· forward movement of medial tibial plateau suggests anteromedial instability (ACL, MCL, medial capsule, posterior oblique ligament)

· foot in 30^o of IR

· lateral structures tightened

· forward movement of lateral plateau suggests anterolateral instability

· damage of ACL, LCL, arcuate complex

Pivot shift

· normal

· glide

· jerk

Posterolateral

· lift feet by great toes

· note increased recurvatum and/or external rotation of tibia

· crank test

· maximally externally rotate tibias with knees at 60^o-90^o

· increase > 15^o cf. other side significant

McMurray

· full flexion and IR / ER

· click

patellofemoral

Look

Q (quadriceps) angle

· knee at 20^o flexion

· legs crossed or over bolster

· ASIS to centre of patella to tibial tuberosity

· normal range is 8-10^o in males and 12-15^o in females

· abnormal if > 15^o in males and > 20^o in females

Feel

Tenderness

· lateral retinaculum

· retropatellar surface

Patellar grind

· pain on compression of the patella

· patella compressed into trochlea

Clark’s test

· gentle pressure on superior pole

· patient asked to contract quadriceps

Move

Patellar tilt test

· patient supine and relaxed with knees extended

· transepicondylar axis placed parallel to table

· lateral edge of patella elevated and medial edge depressed

· normal is 0-20^o tilt

· abnormal if unable to tilt it beyond horizontal

Patellar glide test (Sage sign)

· knee at 30^o flexion

· ability to translate patella medially and laterally assessed

· graded in number of quarter widths that patella displacable

· lateral

· normal is 0 to 2.5 quadrants

· > 3 quadrants is incompetent medial restraint

· medial

· normal is 1 to 2.5 quadrants

· < 1 quadrant is tight lateral restraint

· > 3 quadrants is hypermobile patella

Apprehension test

· patient supine and relaxed

· patella pushed laterally while knee flexed 30^o

· knee flexed

· positive if patient uncomfortable (pain or apprehension)

Special tests

Pulses

· dorsalis pedis

· normal

· diminished

· absent

· posterior tibial

· popliteal

· knee flexed

· pulse

· aneurysm

proximal joint

· hip ROM

· rotation in flexion

· Abd/Add in extension

Popliteal fossa

Prone

· masses

· flexion and extension

Generalised ligamentous laxity

· positive if 4 or more of 5 signs

· thumb touches forearm

· fingers parallel to forearm

· elbow hyperextends 15^o

· knee hyperextends 15^o

· ankle dorsiflexes 60^o