The Knee Flashcards
name the bones of the knee
Femur:
-shaft
-lateral/medial condyle
Patella:
-apex
-base
Tibia:
-medial/lateral condyle
Fibula
meniscus function (4)
- improve joint congruity & stability by deepening articulation
- increase contact between femur and tibia allowed for better load transmission
- disperse forces across the knee
- assist in lubrication and nutrition of the knee
name the 3 zones of the meniscus
red-red (outer most zone)
red-white (middle zone)
white-white (inner most zone)
Which zone of the meniscus gets the most blood supply, why?
red-red
it is the least vascularized and so recieves the most blood supply
ligaments of the knee (4)
- posterior cruciate ligament
- lateral collateral ligament
- medial collateral ligament
- anterior cruciate ligament
function of the oblique popliteal ligament
prevents extensive external rotation and hyperextension
What is a bursa and what are their function?
-Small fluid filled sacs
-Act to reduce friction and provide cushioning against compression
name the bursa’s of the knee (5)
-popliteal bursa
-suprapatellar bursa
-prepatellar bursa
-deep infrapatellar bursa
-subcutaneous infrapatellar bursa
what is bursitis
irritation/inflammation of the bursa
-no MOI
anterior muscles of the knee
quadriceps
gracilis
rectus femoris
sartorius
vastus lateralis
vastus medialis
what can happen if the anterior leg/knee muscles become too weak
causes mistracking of the patella
posterior muscles of the knee (4)
bicep femoris
semitendinosus
semimembranosus
gastrocnemius
nerves of the knee (2)
tibial nerve
common fibular nerve (L4-S2)
why don’t you want to ice on the lateral side of the knee for an extended period of time?
That is where the common fibular nerve runs through and long periods of ice can disrupt the nerve functioning and cause temporary drop foot
Blood supply of the knee (4)
femoral artery
Sural artery
popliteal artery
anterior tibial artery
functional anatomy of the knee: What are the primary muscles used for extension, flexion, medial rotation of tibia & lateral rotation of tibia
Extension: quadricep group
Flexion: hamstring group
Medial rot. of tibia: medial hamstrings & adductors
Lateral rot. of tibia: lateral hamstring (bicep femoris)
what joint is the articulation between distal femur & proximal tibia
tibiofemoral joint
What is the screw home mechanism
last 20 degress of knee extension (terminal end) the tibia externally rotates
what is the ‘closed pack’ position of the knee
knee in full extension where there is maximal contact between femur & tibia
Roles of the ACL (4)
- restrict anterior translation of tibia on a fixed femur
- restrict posterior translation of the femur on fixed tiba
- prevents hyperextension of tibia
- rotation of the tiba on femur
Function of PCL (2)
- restrict posterior translation of tibia on fixed femur
- restrict anterior translation of femur on fixed tibia
Mensicus injury MOI (3)
- joint compression (extreme flexion
- varus/valgus loading
- internal or external rotation
most common meniscus injury
medial meniscus
how are meniscus injuries classified
-by age, location and orientation
-by acute or chronic
MOI for ACL, MCL & Meniscus injury
rotation of femur + valgus force + (opposite) rotation of lower leg
types of meniscus tears (5)
- vertical longitudinal
- vertical radial
- horizontal
- bucket handle
- oblique
S/S meniscus tear (history + palpation/inspection)
History:
-sharp, intense pain at onset
-palpable joint line may be present on respective side
-episodes of instability
Palpation:
- painful & deep
-edema
-limited motion
-episodes of locking up/giving away
-overtime may have swelling, pain, quad atrophy
mensicus tear: management
-knee not locked but has presence of tear= further diagnostics may be needed
-knee locks= surgery + anesthesia
Surgery:
- all efforts made to preserve meniscus
-menisectomy rehab allows partial weight bearing and quick return to activity
-immobilization and gradual return to activity for 12 weeks
what is menisectomy and the pro/cons
-Clipping mensicus instead of sewing it back together
pro:
-can weight bear sooner+return to play sooner
con:
-more risk of OA
-takes out a piece of meniscus that never regenerates (gone forever)
Medial (tibila) collateral ligament sprain: etiology
-direct or indirect MOI
-valgus force at the knee
MCL grade 1 sprain: S/S
-mild fiber disruption
-mild edema
-medial joint line tenderness
-full ROM
-negative valgus stress for instability
-apprehension with cutting/change of direction
MCL & LCL grade 1 sprain: management
-RICE 24hrs
-crutches if they cannot bear weight
-cryokinetics with exercise
-Isometrics, STLR exercises, bicycle riding then isokinetics
-may require 3 weeks to recover
MCL grade 2 sprain: S/S
-complete tear of deep layer and partial tear of superficial layer of MCL
-edema on medial side
-pain and medial joint line tenderness
-knee extension limited due to pain/swelling
-valgus stress @30 degrees positive for instability/pain
-valgus stress test @0 degrees for instability
MCL & LCL grade 2 sprain: management
RICE 48hrs
-possibly brace prior to starting ROM activities
-modalities 2-3 times/day for pain
-gradual progression from isometrics (quad) to isokinetic; functional progression activities
MCL sprain grade 3: S/S
-complete tear of supporting ligaments
-complete loss of medial stability
-min. to mod. swelling
-immediate pain followed by ache
-limited knee extension range of motion
-loss of motion from swelling
-positive valgus stress test at 0 & 30 degrees for instability/pain
MCL & LCL grade 3 sprain: Management
RICE
-limited immbolilization w/brace; progressive weight bearing & increased ROM over 4-6 weeks
-rehab similar to grade I & II
Lateral (fibular) collateral ligament sprain: Etiology
-less common than MCL
-direct varus force that puts tension on LCL
-if laxity then check ACL & PCL
LCL sprain grade 1: S/S
-mild lateral edema & pain
-full ROM
-negative varus stress test for instability
-positive varus test for pain
LCL sprain grade 2: S/S
-lateral edema
-pain + point tenderness
-limited ROM due to pain/swelling
-positive or neg. varus for instability
-pos. varus for pain
LCL sprain grade 3: S/S
-lateral edema
-intense pain then to dull ache
-point tenderness on fibular head may indicate avulsion fracture
-flexed & internally rot. a defect may be palpable
-pos. varus for instability & pain
-possible injury to peroneal nerve, further evaluation needed
ACL sprain: etiology
-landing from a jump
-cutting
-sudden deceleration
-usually in combination with MCL & medial meniscus. Can also be isolated
ACL sprain: MOI (2)
- knee extension (tibial slides)
- valgus collapse (dynamic valgus collapse)
ACL sprain: S/S (history & palpation)
history:
-audible pop, snap or tearing
-deep pain in the knee/anterior on either side of the patellar tendon
-knee giving way
Palpation:
-edema present
-point tenderness on medial and lateral joint lines
-no typical visual or palpable deformities
ACL sprain: management
RICE
-joint degeneration may result if no surgery
-age + activity may factor into surgical option
-surgery may involve reconstruction w/grafts(tendon) transplant of external structures
-requires hospital stay
-bracing
7-12 months rehab
PCL sprain: etiology
-most risk during 90 degree flexion
(fall on bent knee)
-hyperextension or rotational force
PCL sprain: S/S (history/palpation)
history:
-may not hear pop or snap
-minimal pain and athletes may not recognize severity
-slow onset of swelling and sensation of instability
Palpation:
- edema will be present & palpable
-point tenderness along medial and lateral joint lines
PCL sprain: management
RICE
-non operative rehab of grade 1 & 2 focus on quad strength
-surgical: 6 weeks of immobilization in extension w/full weight bearing on crutches. ROM after 6 weeks and PRE at 4 months
