Knee Flashcards
Tibiofemoral Joint
biaxial modified hinge joint
Distal Femur-convex
- medial and lateral condyle
- medial condyle is larger and longer
Proximal Tibia-concave
- composed of 2 tibial plateus
- medial plateu larger than lateral
- fibrocartilaginous menisci attached to each plateu
End feels
Knee extension-firm
Knee flexion-soft
Rectus femoris
hip flexion and knee extension
Vastus medialis, interedialis and lateralis
knee flexion
semitendinosus, semimembranosus, long head of biceps femoris
hip extension and knee flexion
short head of biceps femoris
knee flexion only
gastrocnemius
can assist with knee flexion
not a prime mover
Knee open pack
25 degrees of flexion
knee closed pack
full extension and tibial lateral rotation
Open Chain
concave tibial plateau slides on convex femoral condyle
knee ext: tibia glides anteriorly
Knee flex: tibia glides posteriorly
closed chain
convex femoral condyle slides on concav tibial plataeu
Knee extension: femur glides posteriorly
knee flex: femur glides anteriorly
Screw home mechanism Open Chain
ext:
tibia laterally rotates 30 degrees flexion to 0 degrees
most occuring last 5 degrees
Flex:
tibia medially rotates 0 degrees to 30 degrees-unlocking
Screw home mechanism Closed chain
ext:
femur rotates medially 30 degrees flexion to 0 degrees–locking
flex:
femur rotates laterally 0-30 degrees flexion –unlocking
Menisci
two fibrocartilaginous structures are located on the superior surface of the tibia
serve as a shock absorbers/ load transmission
Menisci deepen the flat superior surface of the tibia
- improves congruency of the articulating surfaces
- improves joint stability
Lateral Meniscus
oval shaped
lies on smaller lateral tibial plateau
smaller
Medial Meniscus
semilunar shaped
lies on larger medial plateau
*more like a moon shape
*Tightly bound to the tibia
effect of knee movement on menisci
Extension:
-femoral condyles tend to push to menisci anteriorly
Flexion:
-femoral condyles pull meniscus posteriorly
Medial and lateral tibial rotation:
- menisci tend to move with the femoral condyles
- follow femoral condyles
Anterior cruciate ligament
anterior tibia to posterior femur
prevents abnormal anterior translation of tibia on femur
resists extremes of knee extension
named for where it originates on tibia and what movement it prevents
Posterior cruciate ligament
posterior tibia to anterior femur
prevents abnormal posterior translation of tibia on femur
resists extremes of knee flexion
Named for where it originates on tibia and what movement it prevents
medial collateral
protects the knee form lateral/valgus stress
lateral collateral
protects the knee from medial/varus stress
Patellofemoral joint
formed by patella and anterior distal femur
increasesmoment arm of quadriceps muscle
redirects forces-pulley
increases the lever arm of the quads increasing the quads strength by 35-50%
patella
sesamoid bone
articulates with trochlear groove on anterior distal femur
artiluating surface is covered with smooth hyaline cartilage
embedded in anterior joint capsule
connected to tibia by patellar tendon
slides superiorly with extension
slides inferiorly with flexion
forces maintaining alignment of patella with trochlear groove of femur
lateral-IT band and lateral retinaculum
medial: VMO, medial retinaculum
Inferior-patellar tendon
superior: quad tendon
Open pack position of patella
full knee extension
Q angle/measurement
angle of 2 lines intersecting
ASIS to midpoint of patella
Tibial tuberosity and midpoint of patella
normal Q angle: 10-15 degrees
women usually have a greated angle
angles greater than 19 degrees the patella tracks more laterally
Medial collateral ligament stability test
valgus stress test
identifies MCL instability
apply pressure and valgus stress at 0 degrees and 30 degrees extension
+ test= excessive gapping at medial joint line
lateral collateral ligament stability test
varus stress test
identifies LCL instabilty
apply varus stress at 0 degrees and 30 degrees extension
+test= excessive gapping at lateral joint line
**gapping at 0 degrees suggest a more severe injury such as ACL or PCL
Lachman’s Test
identifies ACL tear
patient supine with knene flexed 20-30 degrees
*more comfortable and muscles put on slack but ACL is tighter
stabilize distal femur with one hand and grasp proximal tibia
moves tibia anteriorly on femur
+test= excessive movement of tibia
Anterior Drawer Test
Identifies ACL tear
patient supine with knees in hook lying position
sits on patients foot to stabilize lower leg
pull anteriorly on proximal tibia
knee bent to 90 degree
+=excessive anterior movement of tibia
Posterior Drawer Test
identifies PCL tear
pt. supine with knees in hook lying position
sit on patients foot to stabilize lower leg
push posteriorly on proximal tibia
+test = excessive posterior movement of tibia
Sag Test =Godfrey’s test
identifies PCL tear
pt. supine with hips and knees flexed to 90 degrees
lower legs resting in therapist hand or chair
+sign= observable posterior translation of tibia
apley’s compression Grind Test
identifies meniscal tear
patient prone with knee flexed to 90 degrees
therapist applies compressive force through foot and rotates tibia medially and laterally
+test = pain
Apley’s distraction test
identifies lateral or medial ligament tear
pt. prone with knee flexed to 90 degrees
apply distraction force through foot and rotates tibia medially and laterally
+=Pain
McMurray’s Test
identifies meniscal tear
pt. supine
grasps foot of patient with one hand and palpates joint line
knee is passively extended while applying a rotation force (internal/external) while also applying valgus/varus stress
+=a click or crepitus over joint line
micro fracture
small holes down to subchondral bone to stimulate growth of articular cartilage
osteochondral autograph
articular cartilage plugs taken form non WB portion of joint and placed in area of damage
Autlogous chondral implantation
hyaline cartilage cells removed and then grown in a lab
surgically transplanted in area of damage
OA
wearing of joint surfaces which may include bone spurs
may cause genu valgum or varum
possible treatments for mild-mod: cortisone or hyaluronan injections
TKA/TKR
indication:
severe pain from OR or RA and/or significant impairment in functional mobility
Acute Care for TKa
gait- WB depends on if cemented or non-cemented
transfers, stairs
ROM
quad sets, SLR,heel slides,hip abd/add, gluteal sets, ankle sets
Post acute care
progression of ROM with goal of functional ROM for patient
Gold standard 120 degrees or more
normalize gait pattern
strengthening/functional activities
High Tibial Osteotomy
attempts to realign tibiofemoral joint by surgically creating a wedge in proximal in tibia or distal femur
rehab considerations:
- No CKC exercises until secure bone union
- immobilizer
- initially NWB
Common causes of poor patella tracking
large Q angle muscle and fascial tightness pronatory forces at foot hip muscle weakness Medial VMO knee weakness
patellofemoral syndrome
misalignment of patella in trochlear groove
SIGNS:
patellar misalignment
pt. can c/o knee buckling
dull ache of knee at rest, sharper pain with stairs
Chondromalacia= crepitus
-softening/degeneration of articular cartilage underside of patella
miserable malalignment syndrome
wide Q angle
femoral anteversion - IR femur
femoral trochlear groove now medially rotated
patella faces more medially
forces on the patella pull on it laterally
Non-surgical rehab management of patellofemoral syndrome
chondromalacia of patella
strengthen quadcrips-VMO
stretching/mobilization of tight structures pulling laterally on patella
patella alignment brace
patella taping
surgical management- lateral retinaculum release
release of lateral retinaculum with goal of improved neutral patellar tracking
if histroy of patellar dislocations
surgery using hamstring graft
reconstruction of medial patellofemoral ligament
ACL injury/ Tear
ACL functions to prevent anterior translation of tibia on femur
Injury:
-forceful hyperextension
blow to knee
+/or twist with foot planted
CLINICAL SIGNS:
-person may hear or feel a pop usually with immediate pain
immediate swelling-intracapsular
TESTS:
- lochmans
- anterior drawer sign
ACL injuries in females
2-10 x more common in females than males LE alignment-increased Q angle estrogen/progestrone and joint laxity Biomechanical risk factors: -increased lateral trunk motion and valgus torques on the knee
Non Op Acute phase-ACL
immobilization control swelling increase ROM strengthening may need brace to protect against rotation forces
Operative management ACL
Autografts:
middle third of patellar tendon
hamstrings
Artificial-may degenerate over time
special rehab considerations after ACL repair
follow MD protocol
graft goes through a point of necrosis during first few months-it becomes fragile and stresses must be controlled
PROTECT GRAFT
brace-may be locked into extension at first
NO OPEN CHAIN EXTENSION
**NO TKE in from 15-45 degrees
Avoid CKC 60-90 degrees of flexion early on
Quad working will cause anterior translation
no additional resistance to distal tibia with quad strengthening
PCL injury/tear
PCL prevents posterior translation
occurs when there is excessive force that moves the tibia posteriorly
falling on knee
blow to anterior knee with knee flexed
Clinical signs of PCL injury
immediate pain
immediate swelling
Tests for PCL injury
Sag test
posterior drawer sign
NON OP management PCL-ACUTE
RICE
immobilization
Quadricep strengthening-reinforces knee and decreases posterior translation
No open chain hamstring strengthening
**avoid for 6-12 weeks
**pulls/contracts causes a pull on tibia posteriorly
NON OP management PCL-SUB ACUTE
closed kinetic chain exercises as tolerated
strengthening of hamstrings once quadriceps strength is good
PCL Graft options
can be from quad, hamstring or gastroc
allowgraft
can be from donor
Special rehab considerations for PCL
follow MD protocol
avoid exercises and activities that place excessive posterior shear forces and causes posterior displacement of the tibia on the femur
NO open chain AROM knee fleixion for 2-3 motnhs
Be aware as patient progresses toward functional exercises:
- avoid downhill inclines
- avoid activities that involve rapid deceleration with both feet planted
MCL injury
provides medial stability
- valgus stress
- lateral to medial blow to the knee
Tests for MCL
valgus stress test
unhappy triad
MCL tear
ACL tear
medial meniscus tear
LCL tear/injury
varus stress
medial to lateral blow to the knee
lateral stability of knee
Tests for LCL
Varus stress test
management of MCL/LCL injuries
can be nonsurgical or surgical management
may have other injured/torn ligaments
acute management=RICE
follow MD protocol
Meniscus tear
degenerative tear
sudden trauma to knee
-often occurs when leg s planted and body twists over leg
Medial Meniscus movements
ABD
IR
Lateral Meniscus movements
ABD
ER
clincial signs of meniscus tear
locking or catching of knee
swelling
constant or intermitten pain along joint line
tests for mensiscus tear
McMurray’s Test
Apley Compression Test
4 Types of meniscus tears
Vertical
transverse
bucket handle
flat
Options for MCL tear
location of tear will predict management of tear due to vascularity
–OUTER EDGE: more vascular, may do well without surgery
–INNER PORTION: less vascular and will need surgery
Partial meniscectomy
usually in white zone
often outpatient surgery
physical therapy immediately
slowly return to weight bearing
Meniscus repair
usually associated with other ligamentous repairs
follow MD protocol-depending on what was repaired
usually weight bearing precautions
RED ZONE of meniscus
decent blood supply
WHITE ZONE
compromised blood supply
Patellar fracture
blow to knee or fall
signs;
- pain
- swelling
- xray
treatment:
- non displaced= immobilization
- displaced or comminuted= WB limitations, Quad contraction restriction
- -painful-> follow MD protocol
Supracondylar femur fracture and Tibiofemur fracture
follow MD protocol
Post-surgical general PT guidelines for knee
IN PATIENT: -bed mobility, transfers OKC exercise program -femoral nerve block or no quad control=use knee immobilizaer -ambulation training with AD -enviornmental barrier training -compression and cold packs-DVT prevention -1-4 days in hospital
Max protection phase of Knee
pt. education of procedure and long term outcomes
well joint motion
knee ROM: 0-90 ASAP
GOAL:
Max 0-full flexion
STM
gait training, progressive AD weaning
strengthening: isometrics, isotonics, OKC, CKC
balance
supportive modailities
Controlled motion phase guidelines
CRITERIA:
Ind. SLR, decreasing Edema, improving ROM, full WB
- wean from AD
- max ROM
- max strength: OKC, CKC
- max mobility and tissue
- max balance
- functional acitivities
- environmental barriers
Return to function phase Knee
CRITERIA:
weaned from AD if appropriate, appropriate balance strategies, normalized gait on level surfaces and env. barriers, resolved edema, nearly full ROM, minimal to no pain
- functional activities
- return to recreational acitivies with support of new joint limitations
- if applicalble: plyometrics and return to sports activities
