Knee exam Flashcards
Anterior inspection of knee
- quadriceps bulk
- knee swelling/deformity
- foot deformity
Lateral inspection of the knee
- knee flexion
- arches
- foot deformity
Posterior inspection of knee
- iliac crest alignment
- gluteal muscle bulk
- popliteal swellings
- hindfoot abnormalities
After inspection, what palpation-type examinations do you perform?
1) Assess and compare joint temperature
2) Palpate knee with leg straight
3) Patella tap
4) Swipe test
5) Palpate knee at 90deg flexion
6) Measure and compare quadriceps circumference
After palpation, what active examinations and special tests are done?
1) Active knee flexion and extension
2) Passive knee flexion/extension
3) passive knee hyperextension
4) ant/post drawer test
5) Lachman’s test
6) Assessment of medial/lat collateral ligaments
What are you looking for on posterior inspection of the knee?
SCARS
WASTING
- asymmetry in the muscle bulk suggestive of disuse atrophy or LMN lesion.
POPLITEAL SWELLINGS
- Baker’s cyst
- popliteal aneurysm
Gait assessment knee exam
- toe off/heel strike abnormalities
- ROM
- Limp- joint pain/weakness/instability
- Leg length discrepency
- Step height- high stepping Ax with foot drop
6 phases of the gait cycle
1) Heel-strike: initial contact of the heel with the floor.
2) Foot flat: weight is transferred onto this leg.
3) Mid-stance: the weight is aligned and balanced on this leg.
4) Heel-off: the heel lifts off the floor as the foot rises but the toes remain in contact with the floor.
5) Toe-off: as the foot continues to rise the toes lift off the floor.
6) Swing: the foot swings forward and comes back into contact with the floor with a heel strike (and the gait cycle repeats).
What are you inspecting for with the patient lying on the bed?
Scars Swelling Bruising Quadriceps wasting Knee joint asymmetry Fixed flexion deformity Abnormal patellar position
Bed position for knee exam
45 deg headrest for inspection then supine for palpation
When palpating the patella, what pathologies do you look for?
- tenderness- injury/arthritis
- apprehension with mobilisation (laterally) suggests history of dislocation
- tenderness on palpation of patellar ligament suggests rupture/inflammation
Tenderness on palpation of the medial and lateral joint lines of the knee suggests what 3 pathologies
- Fracture
- Meniscal injury (e.g. meniscal tear)
- Collateral ligament injury (e.g. rupture)
Patellar apprehension test
- patient knee fully extended
- apply lateral pressure
- simultaneously flex knee joint
- active resistance from patient suggests patella instability + dislocation
Causes of knee joint effusion
- ligament rupture (e.g. ACL)
- septic arthritis
- inflammatory arthritis
- osteoarthritis
Tests for moderate-large knee joint effusion
Patellar tap
Explain the patella tap test
Screen for the presence of moderate-large effusions
1) With knee fully extended, empty the suprapatellar pouch by sliding your left hand down the thigh to the upper border of the patella.
2. Keep your left hand in position and use your right hand to press downwards on the patella with your fingertips.
3. If there is fluid present you will feel a distinct tap as the patella bumps against the femur.
Test for small knee joint effusions
sweep test
describe the sweep test
- Position the patient supine with knee extended.
- Empty the suprapatellar pouch by sliding your left hand down the thigh to the upper border of the patella.
- Stroke medial side of the knee joint to move any excess fluid across to the lateral side of the joint.
- Now stroke the lateral side of the knee joint which will cause any excess fluid to move back across to the emptied medial side of the knee joint.
This causes the appearance of a bulge or ripple on the medial side of the joint indicating the presence of effusion.
After palpation of the extended knee, what do you do?
repeat palpation:
- patella
- med/lat joint lines
- patella tap
- sweep test
but with the knee flexed at 90 deg
also:
- tibial tuberosity and head of fib
Palpation of tibial fossa can show what pathologies?
- popliteal (bakers) cyst = fluctuant swelling, tense on extension and soft on flexion
- popliteal aneurysm = pulsatile mass
Osgood-Schlatter disease
Inflammation of the patellar ligament at the tibial tuberosity (its insertion point)
Osgood schlatter disease epidemiology
10-15yr old males
sports involving running and jumping
Normal ROM for active knee flexion
0-140 degrees
abnormal degree of hyperextension for the knee?
anything more than 10 deg
Tests for PCL rupture
Posterior sag sign
Posterior drawer test
Test for ACL integrity
Anterior drawer test
- supine with knee flexed to 90deg
- wrap hands around proximal tibia with fingers round back of knee
- position thumbs over tibial tuberosity
- pull tibia anteriorly and feel for anterior movement of the tibia on femur
Posterior sag sign
- flex knee at 90 deg with foot flat on bed
- inspect lateral aspect of knee
DO BEFORE ANTERIOR DRAWER as ruptured PCL can lead to false positive
Posterior drawer test
- supine with knee flexed to 90deg
- wrap hands around proximal tibia with fingers round back of knee
- position thumbs over tibial tuberosity
- pull tibia posteriorly and feel for posterior movement of the tibia on femur
origin and insertion of ACL
- origin is medial wall of the lateral femoral condyle
- inserts in anterior region of intercondylar area of tibia
Primary purpose of PCL
stabilise the knee joint by preventing posterior tibial subluxation
(i.e. prevent posterior displacement of the tibia relative to the femur).
Primary purpose of ACL
Stabilise the knee joint by preventing anterior tibial subluxation
(i.e. prevent anterior displacement of the tibia relative to the femur).
Causes of PCL/ACL injuries
ACL = one-legged pivot movement in opposite direction to landing
PCL = hyperflexion of knee eg falling on flexed knee
varus vs valgus
tests for medial and lateral collateral ligaments
varus (lateral) and valgus (medial) stress test
- Extend knee fully
- Hold ankle against your side
- Position your palm over the medial/lateral aspect of the knee.
- Position other palm lower down over the opposite aspect of the lower limb, with your fingers reaching upwards to palpate the knee joint line.
- Push steadily outward with your right palm whilst pushing inwards with the left palm.
- Whilst performing this manoeuvre, palpate the medial/lateral knee joint line with the fingers of your left hand.
Medial/lateral meniscus test
McMurray’s test
MEDIAL: varus stress by external rotation and abduction
LATERAL: valgus stress by internal rotation and adduction
function of menisci
Stabilise the knee joint and distribute friction between the femur and tibia.
typical meniscus tear injury Sx
sudden-onset pain, a popping sensation, locking and instability of the knee joint.
2/2 sudden twisting
