Download Knee Anatomy (1)

Knee Anatomy (1)
Modified hinge joint

flexion/ extension, internal/ external
rotation
Two distinct joints
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tibiofemoral joint
Patellofemoral joint
Knee Anatomy (2)
Tibiofemoral joint

condyles of the femur
 very rounded
 medial condyle is larger than the lateral
condyle
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Tibial plateaus
 flattened, very slightly concave

“Screw home mechanism”
 required to reach full extension
 tibia rotates laterally on the femur to produce a
locking of the knee
Knee Anatomy (3)
Patellofemoral joint

patella
 triangular shaped seasamoid bone: protect the knee joint

femur
 Patellofemoral groove or trochlear surface
Q angle
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The angle of pull of quadriceps on the patella
normal is 13 degrees male/ 18 female
Knee Anatomy (4)
Menisci
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firbrocartilage discs
Functions:
1) deepen the tibial plateaus or joint
2) absorption and dissipation of force
3) congruency of the surface to improve wt
distribution
4) nourishment and lubrication of joint
surfaces
Thicker along the lateral portion
Menisci Cont

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Poor blood supply (only outer 1/3 receives
direct blood supply) Fig 11-5-C
Medial is C shaped; Lateral is O shaped
The medial is more commonly injured
because of its attachment to the MCL
ligament & more securely attached to the
tibia (which makes it less mobile)
Knee Anatomy (5)
4 main ligaments- help stabilize knee jt
Medial Collateral (Tibial Collateral)
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prevents valgus & rotational forces/stresses
Attaches to medial femoral epicondyle and
anterior medial tibia
Lateral Collateral (Fibular Collateral)
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prevents varus struss
Attaches to lateral femoral epicondyle and head of
fibula
Knee Anatomy (6) Fig 11-9
Anterior Cruciate (ACL)
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Prevents tibia from moving forward/ femur
from going back
attaches to lateral femoral condyle/ medial
tibia at intercondylar eminence
Posterior Cruciate (PCL)
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
Prevents tibia from moving backward/
femur from going forward
attaches to medial femoral condyle/ lateral
tibia at intercondylar eminence
Knee Anatomy (7)
Bursa – Fig 11-2 C
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formed by joint capsule
function to reduce friction
several:
 Suprapatellar: largest in body
 Prepatellar: between skin and patellar tendon
(housemaids knee)
 Infrapatellar: below petella (superficial and
deep)
 Pes anserine bursa- medial proximal aspect of
tibia
Knee Anatomy (8)
Muscles-contribute to jt stability
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Quadriceps (EXT): Vastus lateralis, vastus
medialis, rectus femoris, vastus
intermedius; quads also aid in patella
alignment
Hamstrings (Flex): Semitendinosus (IR),
Semimembranosus(IR), Biceps Femoris
(ER)

Gastroc (Flex), Sartorius(Flex/IR), Gracilis
(Flex/IR), & popliteus (Flex)
Knee Anatomy (9)
Blood supply – Fig 11-5

femoral artery to popliteal artery, then
medial superior/inferior genicular, lateral
superior/inferior genicular
Nerve Supply

Femoral nerve(Ant); Sciatic nerve (post) to
tibial nerve and common peroneal nerve
Prevention of Knee Injuries
Stretching and strengthening of knee (FS
11.1)
Protective Knee Braces
Three types: prophylactic, functional, and
rehabilitative (Fig 11-6)
Patellofemoral- Fig 11-7- “Cho-Pat” strap:
horseshoe knee sleeve
Proper footwear- correct shoe for the correct
surface
Treatment of Knee Injuries
Normal acute protocol and NSAIDs
Progression of cold to hot treatments
Control swelling, fit for crutches if
necessary,increase ROM and strength
Return to competition the safest and
quickest way possible thru rehab,
functional activities, and sports specific
activities
MCL Injuries
MOI: valgus stress or lateral forces, internal
rotation
HOPS
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Pain and swelling over the medial joint,
pn over medial epicondyle or medial tibia,
+ valgus stress test
Tx

hinged knee brace, treat symptoms, strengthen
musculature, rule out meniscus tear with MRI; will
heal by itself with conservative treatment;
immobilize
LCL Injuries
MOI: Varus stress or medial forces
HOPS
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Pain and swelling over the lateral joint,
pn over lateral epicondyle or fibular head,
+ varus stress test
Tx

hinged knee brace, treat symptoms, strengthen
musculature; immobilize; can heal by itself
ACL Injuries
MOI:

Sudden deceleration, blow to lateral leg
with the knee bent, foot fixed
HOPS
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Immediate pain and swelling; hot knee;
Pain “inside the knee”; knee “feels loose”,
“something not right”
+ anterior drawer stress test and lachmans
Tx

depends on the severity, with 3rd degree =
surgery; treat symptoms; immobilize
PCL Injuries
MOI:

Fall on a bent knee; posterior force on tibia,
hyperextension
HOPS
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Immediate pain and swelling; hot knee; Pain in
the popliteal fossa; knee “falling apart” knee “feels
loose”
+ posterior drawer stress test, posterior sag test
Tx

depends on the severity, immobilized, strengthen
knee musculature; surgery
Menisci Injuries
MOI: Twisting with foot fixed
HOPS

Pn over the joint line, catching/locking or
giving out of the knee. Popping or clicking
in joint line, swelling after activity with little
heat, Pn with or deep squat
Tx

strengthen knee musculature, surgery if sx
persist; recovery time depends on type of
surgery and tear
Patello Femoral Stress Synd.
Precursor: females, high Q angle, weak VMO,
MOI: lateral riding of the patella
HOPS

dull achy pain in the center of the knee, pn with
compression of the patella
Tx

isometric quad contractions, strengthen/stretch all
surrounding musculature , closed chain exercises;
knee braces; surgery last option
Chondromalacia
Degenerative condition of the articular
cartilage of patella
Precursor: females, high Q angle, weak VMO,
MOI: lateral riding of the patella
HOPS

pain going down stairs, crepitation under patella
Tx: knee sleeve, avoid knee bends’
strengthening of VMO; surgery last option
Subluxing/ Dislocating patella
MOI: decelaration with cutting
maneuver
Other injuries that may occur with
sub/dislocating patella: may tear the medial
retinaculum and or quad tendon, bruise
patella and lateral femoral condyle
HOPS

pop, violent collapse of knee, + Pattella
Apprehension test, obvious deformity
Tx: RICE, splint if able refer to a
physician
Patellar Tendonitis
“Jumper’s knee”
MOI: overuse
HOPS
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Pn over the patellar tendon, crepitation in
tendon, thickening of the tendon, pain
after prolonged sitting, pn walking stairs,
Tx

Rest, eccentric quad strengthening, stretch
hamstrings, treat symptoms, taping,
bracing
IT Band Friction Syndrome
Occurs when the IT band snaps over the
lateral femoral condyle
Precursor: distance runners, cyclist, large Q
angle
MOI: overuse
HOPS
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Pn while running up and down hill, point tender
over the lateral femoral condyle
Tx

Box 11-3; look at the shoes
Osgood Schlatter Disease
Inflammation or partial avulsion of the tibial
apophysis due to traction forces (Fig 11-14)
Precursor: adolescent athletes (male 10-15;
female 8-13)
MOI: overuse; jumping and cutting type
sports
HOPS
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Pn over the tibial tuberosity, bony growth of tibial
tuberosity; a knot will form
Tx

treat symptoms, padding, complete rest (may be
needed); will usually grow out of condition
SPECIAL TESTS
Range of motion
 AROM N= 135 flex
0 extension
 RROM
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Flexion with IR/ER- prone
Extension - seated
Stress Tests + Laxity; Note Pain
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Valgus = MCL; p.214 Fig 11-19
Varus = LCL; p.214 Fig 11-19
McMurray’s Click- Menisci
SPECIAL TESTS (2)
Stress Tests
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Anterior Drawer = ACL; p.214 Fig 11-18a
Posterior Drawer = PCL; p.214 Fig 11-18a
Lachman’s= ACL; See class demonstration
Posterior Sag = PCL; p.214 Fig 11-18b
Patellar apprehension = Subluxing Patella;
+ sign is apprehension; p.214 Fig 11-20
Ober’s test = IT band contraction; + knee
doesn’t fall into Adduction; p.215 Fig 11-21
Links
http://www.scoi.com/kneeanat.htm
http://www.swarminteractive.com/prod
ucts_licensing.shtml
http://www.sportsknee.com/kneeanato
my.htm - Anatomy Review
Links
http://www.arthroscopy.com/sp05018.h
tm- ACL Surgery
http://www.sportsknee.com/acl.htm
Step by Step of an ACL Surgery
http://www.csuchico.edu/~sbarker/injur
y/knee/ - Knee Scenario