Lecture 5 - Knee Ax Flashcards
Largest joint in the body
Tibiofemoral joint
Allows for end range/rotation at knee
Does not move much
Superior tibiofibular joint
Resting position of tibiofemoral joint
Closed packed position
Capsular pattern
25° flexion (open pack)
Full extension, lateral rotation of tibia
Flexion, extension
Which joint improves efficiency of ext. and guides quads, is often overlooked and needs to move well to avoid injuries (friction)?
Patello-femoral joint
Type of joint for tibiofemoral?
Hinge joint (modified)
Cruciate ligaments are ____ capsular
extra
Meniscus movement - Medial is __ and ___ mobile
Larger and less mobile
Meniscus movement - lateral is ___ mobile
More
Which meniscus has a higher tendency to get injured?
Medial
Functions of the menisci for the knee (4)
- Aid in lubrication and nutrition of the joint
- Act as shock absorbers
- Make the joint surfaces more congruent
- Improve weight distribution
Menisci is primarily ___ (vascular or avascular) with __ (high or low) regeneration potential
Avascular / low
T or F: the medial meniscus may heal on its own from the blood supply of the MCL (proximity of attachments)
TRUE
C-shaped part of knee
O-shaped part of knee
Medial
Lateral meniscus
Both menisci are ___ along periphery and ___ along inner margin
Thicker / thinner
What is the consequence of an odd relationship between the patella and the femur?
Patellofemoral syndrome (PFS)
Type of joint of patellofemoral?
Plane joint (modified)
Thickest layer of cartilage in body
Patella
Patellar loading with activity - Walking
0.3 times BW
Patellar loading with activity - climbing stairs
2.5 times BW
Patellar loading with activity - descending stairs
3.5 times BW
Patellar loading with activity - squatting
7 times BW
Type of joint superior tibiofibular joint
Plane synovial joint
Consequence of hypomobility at superior tibiofibular joint?
Pain in knee area on activity, because the fibular can bear up to 1/6 of BW
Look at table 12.1 in OPA
p.873
MOI for Hx of knee injury (8 examples)
- Valgus force
- Varus force
- Hyperextension
- Flexion with posterior translation
- Instability/giving away/locking
- Functional impairments
- Deceleration/acceleration
- Contact/Non-contact
Observation (4 things)
- Malalignments (genu varum/valgum + patella)
- SHARP
- Cyst’s? Osgood-Schlater? Bursitis?
- Gait
Observation - anterior view (standing) what to look for?
Any malalignment including genu varum of valgum
Patella position (tilt and rotation + quad atrophy)
Observation - lateral view (standing) what to look for?
- Genu recurvatum
- Patella alta vs patella baja or patella infera
- Note if inferior pole of the patella is tilted in (inferior tilt)
High patella
Patella alta
Low patella
Patella baja or infera
Observation - posterior view (standing) what to look for?
Look for abnormal swellings, such as a popliteal (Baker) cyst.
What is a quad lag?
Inability to fully extend because the quadriceps muscle are not strong enough
Explain the path of the patella as the knee moves from extension to flexion
Curved pattern
Moving medially in early flexion and then laterally
To complete the last 15° of knee extension, a ___ increase in force of the __ muscles is required
60% / quadriceps
What do you do for passive?
ROM
Overpressure
Patellar movement
About ___ of flexion is necessary for activities such as squatting to tie a shoelace of to pull on a sock
117°
Sitting on a chair requires approximately ___ of flexion
90°
Climbing stairs (average height) requires approximately ___ of flexion
80°
Resisted at knee
Flexion/extension
Ankle DF/PF
Clear capsular pattern of the joint
When is it okay to move on to functional tests?
If passive/active/resisted isometric movements is performed with little difficulty
Sequence of functional testing (10 steps)
- Walking
- Ascending and descending stairs (walking -> running)
- Squatting
- Squatting + bouncing at the end (pulse)
- Running straight ahead
- Running straight ahead and stopping on command
- Vertical jump
- Running and twisting (carioca, figure 8)
- Jumping and going into a full squat
- Hard cuts, twists, pivots
3 things related to ligament instability
- Primary vs secondary restraint (table 12.8)
- One plane instability
- Rotational instability
When testing for ligament instability of the knee, keep in mind (5)
- Test normal knee first to establish baseline
- When comparing normal/injured limbs, perform the same test for both limbs
- Muscles must be relaxed
- Gently apply appropriate stress
- Repeat stress several times and increase it to point of pain to demonstrate maximum laxity without causing muscle spasm
Common ligament tests (7)
- Varus/valgus
- Lachman’s
- Ant. & post. drawer
- Pivot shift
- Reverse pivot shift
- Slocum
- Sag
Varus stress test
Lateral stress
Valgus stress test
Medial stress
Lachman test
Anterior instability
Anterior drawer vs posterior drawer test
Anterior and posterior instability
Slocum test
Ant/med & ant/lat
Pivot shift test
3rd degree ACL CAUTION
Reverse pivot shift
posterior/lateral instability
PCL testing - name test + explain
Godfrey test - examiner watches for posterior shift of tibia when in 90° flexion
Sag sign
Posterior shift of tibia - will have +ive ant. drawer but not coming from ACL, more from the PCL laxity
Common meniscus tests (4)
- McMurray’s
- Apley’s (compression and distraction)
- Bounce home
- Thessaly test
Signs and symptoms of meniscus injury (6)
Joint line pain
Loss of flexion (more than 10°)
Loss of extension (more than 5°)
Swelling (synovial)
Crepitus
Positive special test
McMurray test (what’s a +ive)
Medial meniscus or lateral meniscus
++ test -> snap or click could possibly mean a torn medial meniscus
Tests for swelling (3)
- Brush/stroke or bulge test
- Patellar tap test
- Girth measurements
Tests for patellofemoral dysfunction (5)
- Clarke’s sign
- Eccentric step test
- McConnell test for chondromalacia patellae
- Step up test
- Vastus medialis coordination test
Vastus medialis coordination test - 2 things to look at & +ve meaning
- ability to do it
- ability of VMO to contract (palpate)
+ve indicates quad lag
Test for plica
Mediopatellar plica test
ITB test
Noble’s compression
Joint play for knee (5)
A-P tibio-femoral
M-L tibio-femoral
M-L displacement of patella
Patellar depression
A-P Tib-Fib
Neurological considerations (3)
Myotomes
Dermatomes
Reflexes
What are the two reflexes and cutaneous distribution?
Patellar (L3-L4) and medial hamstring (L5-S1) reflexes
Diagnostic imaging (5)
- Plain film radiography
- Arthroscopy
- Computed tomography
- Magnetic resonance imaging
- Xeroradiography
Knee muscles and referral pain - see p.79 ppt
READ AND LEARN
Peripheral nerve injuries about the knee - see p.81 ppt
READ and LEARN