Knee
Knee
Joint type
Anatomically
Synovial
Functionally
Hinge
Physiologically
Rotation/rolling and gliding
Bones
Femur
Tibia
Patella
Quad tendon connects quad to patella
Patella tendon connects patella to tibia
Articulations
Tibiofemoral
Femur and tibia
Patellofemoral
Patella and femur
Structures that contribute to stability
Capsule
Ligaments
Menisci
Muscle
Tendons
Capsule
A sheet of dense fibrous connective tissue that withstand constant joint movement
Completely surrounds the articulating bones
Filled with synovial fluid for lubrication
Anteriorly, Extends upwards underneath patella for the infrapatellar fat pad and bursa
Medially, forms the deep portion of the medial collateral ligament
Posteriorly, forms pouches that cover the femoral condyles and tibial plateau
It is extensive and redundant
Capsule covers a large area of the joint
Therse available space at the front of the knee as the area around the patella is more accessible and offers more space for fluid to gather as the capsule is loose around the patella to allow the movement of it
It results hyperextension
Provides rotational stability
Ligaments
Extracapsular
It controls side to side movement
Stability and direct movement in correct path
Medial collateral Lig. (MCL)
Short inner, long outer fibres
Prevents inward rotation, or valgus movement
Attaches at the medial epicondyle (femur) and medial condyle of the tibia
Lateral collateral (LCL)
Attaches to lateral epicondyle of femur and head of the fibular
Prevents outward rotation or varus movement
Intracapsular
Stability
Control movement between femur and tibia
Helps with rotational stability
Anterior Cruciate Lig (ACL)
Starts posteriorly on the femur and ends anteriorly on the tibial
Prevents anterior displacement of tibia and prevents posterior displacement of femur
Prevents hyperextension
Stabalizes against excessive internal rotation and a secondary restraing for valugus or varus stress
Posterior Cruciate lig (PCL)
Starts anteriorly on femurs and ends posteriorly
Prevents Posterior displacement of tibia and Anterior displacement of femur
Resists internal rotation of tibia and prevents hyperextension
Menisci
Fibre cartilage
Medial and lateral
Attached to tibial plateau
Connects to the extracapsular ligaments by the coronary ligament
Provides cushioning and stability
Increase blood/nutrient circulation?
Maintains spacing between femoral condyles and tibial plateau
Acts as a cushion
Cushions stress placed on the knee joint
Acts as a sponge
It soaks up synovial fluid and when bending it squishes the fluid out to help circulate nutrients
Blood supply
Outer 1/3 is the redone, good blood supply
Middle 1/3 is the pink zone, it has minimar blood supply
Inner 1/3 is the white zone, no blood supply
Medial meniscus
Takes valgus and torsional forces
Will feel pain on external rotation of the tibia
Tibia rotates externally, meniscus moves under the femur condyle
Like a C shape
Lateral meniscus
Takes varus and tortional force
Will feel pain on internal rotation of the tibia
Like an O shape
Muscles
Quadricep femoris
Rectus femoris
Originates at ilium at anterior inferior iliac spine
Vastus medialis, vastus intermedias, vastus lateralis
Originates at the femur
All insert by the quadricep tendon and patellar tendon on the tibial tuberosity
Function is extension of the knee
Quad helps the PCL and prevents tibial posterior displacement
Hamstring
Origins at the ischium
Bicep femoris
Inserts on the head of the fibula
Semimembranosus and Semitendinosus
Insert on the anterior medial tibia
Flex lower leg on thigh at knee
Extend thigh on trunk at the hip
Helps ACL and prevents tibia anterior displacement
Tensor Fascia Lata (TFL)
Originates at the ilium
Inserts on the tibia and into the fascia of the thigh, the iliotibial band, IT band
Helps flex and abduct thigh on trunk at hip
Adds to lateral stability of the knee
Gracilis
Origins at the ischium, insert on the anterior medial tibia
Assists with knee flexion
Bursae
Prepatellar bursa
Anterior to the patella
Suprapatellar bursa and fat pad
Superior to the patella on the femur
Infrapatellar bursa and fat pad
Inferior to the patella on the tibia
Inflammation of the bursa is bursitis
Movement of knee
Flexion and extension
Gliding of condyles on the plateau and meniscus
Flexion is anterior glide and posterior roll of femur
Condyles move forward and roll back
Extension is posterior glide and anterior roll of femur
Condyles move back and roll forward
"Locking mechanisms"
Femur internally rotates to lock the joint
When the knee extends from a flexed position, the tibia externally rotates relative to the femur or the femur internally rotates to complete full extension at the knee
This can cause increased tension and shear force on medial meniscus and cause distortion
Tears, deformation, hypomobility
Popliteus
Major stabilizing muscle of the knee
Located on the back of the knee
Knee flexion and external rotation of the femur
Knee Asessment
Hx, PHx (prior knee injury? did it fully heal? Rehab?
Ssx
Pain, tenderness
"snap", "pop"
Examination
Observation
Limp or instability
Swelling (acute or delayed)
Swelling indicates intracapsular injury
ROM
Functional tests
Compare both sides
Thigh circumference
Is there noticeably swelling
Long swelling will cause atrophy of the quads
Palpation
Knee Alignment deviations
Patellar malalignments
Check if the kneecaps have shifted out of the trochlear groove and are pulled toward the outside of the box
Q angle
Angle between the Anterior superior iliac spine and the midpoint of the patella
Will indicate the alignment of the knee
An angle less than 15 degrees is normal
Angle greater than 20 degree is Genu Valgum, knock kneed
Less than 10 degrees is genu varum, bow-legged
Genu recurvatum
Hyperextension
Genu antecurvatum
Can't extend
Weight-Bearing Functional Assessment
Gait
Squat
Single leg squat
Thessaly
Mensiscus
Bend and twist
Duck walk, Childress Test
Meniscus
2 legged hop
Single leg hop
Non-weightbearing ROM
Flexion/extension
Active
Passive
Resisted (strength)
Valgus Stress test
Test the MCL
Push the lower leg laterally
Push the femur/knee joint medially
Normal tests will see resistance from the knee
Positive tests will see a considerable ROM of the knee
Varus Stress Test
Tests the LCL
Push the lower leg medially
Push the femur/knee joint laterally
Positive test will see a considerable ROM
Intracapsular Swelling tests
Patellar compression
Ballottement
Swipe Test
Swipe medially of the patella 5-6 times
Swipe laterally of the patella once, if there any movement of liquid going back to the medial side, it confirms swelling
ACL Assessment
Anterior drawer
Lachman's
Pivot shfit
All assessments test for the anterior displacement of the tibia
MRI accuracy for diagnosis of an ACL injury is 95% and more
PCL Assessment
Posterior sag
Posterior drawer
Tests for posterior displacement of the tibia
Meniscus Assessment
Apley's Compression
Mcmurry
Compress and rotate the meniscus
Medial
Knee at 90 degree, push knee medially, rotate foot externally to apply stress
Lateral
Push knee lateral and foot internal rotation
Joint line tenderness
Contusions
Direct blow and worse if muscle is relaxed
Ssx
Pain, tenderness
Swelling, circumscribed
Discolouration
Limp
Tx
POLICE for 2 days
ROM and padding
Physiotherapy and rehabilitation
No massage, no heart over bruise
Myositis ossificans
Bursitis
Direct blow or kneeling
Overuse
Ssx
Inflammation
Redness, heat, swelling, pain, loss of function
Tenderness
Painful on knee extension if infrapatellar or suprapatellar
Tx
POLICE, padding, NSAIDs
Heat, physio, rehabilitation
Early aspiration if acute and traumatic
Complications
Chronicity, recurrence, infection
Sprains
Direct blow, valgus and anterior
Torsion or hyperexteions
Worse if foot is fixed (planted)
1st degree
Mild pain and swelling
No limp or effusion or increase laxity
Tx
POLICE, physio
Brace
2nd Degree
Pain, tenderness, snap
Swelling and effusion if intraarticular
Limp
Increased laxity with a firm endpoint
Tx
Same as 1st degree and see MD
Longer recovery period
3rd Degree
Complete rupture of the ligaments
Ssx
More pain, tenderness, snap
Marked swelling and effusion
Unstable or won't bear weight
Increase laxity with a soft endpoint
Tx
NPO
Stabalize, get to hospital
Need brace and/or surgery
Follow with extensive physio and rehab
Meniscal Tear
Torsions and hyperextension
Rotation of the femur will cause the condyle to glide on top of the tear
Ssx
Acute
Pain or tenderness
Effusion
Chronic or acute
Locking or buckling
Intermittent pain, swelling, effusion
Positive McMurray's and Apley's test
Tx
Physio
Arthroscopic repair or excision
Capsular Tear
Connective tissue tears
Torsion
Hyperextension
Ssx
Pain, swelling maybe
Tenderness
Cause rotary instability
Mimix torn meniscus or tendon injury
Tx
Rest, physio, rehab
Surgery if symptoms persists
Patellofemoral Pain syndrome
Pain around the patellofemoral joint
Related to abnormal tracking of patella in the femoral groove
Cause of the track can be from genu valgum, external tibial torion, over pronation, greater than normal Q angle
Tight quad musculature
Tigh of adductors
Chondromalacia Patellae
Softening and deterioration of cartilage on the back of the patellae
SSx: pain walking up or down, running and squatting
Tx: Conservative (POLICE, NSAIDS, active modification, strengthening, orthoticts)
Surgery is last option
Patellofemoral Stress syndrome
Lateral tracking of patellae in femoral groove
Tight lateral musculature, weak hip adductors/stabilizers
Ssx: pain lateral patellae, crepitus with patellar compression
Tx: POLICE, avoiding aggravating activities, strengthening VMO over VL. Streching lateral soft tissues, Mcconell taping/bracing
Patellar Subluxation/Dislocation
Patella is out of place and not in femoral groove
Unhappy tried
Seen more in female sex, could be hormonal
Acl Tear
Positive anterior drawer, Lochmann's test, pivot shift
Effusion
Snap
MCL tear
Valgus instability, point tenderness
Mensical Tear
Tenderness
Locking or buckling
Capsular tear
Tx
Reconstructive surgery
Brace, physio, rehab
NB, effusion? Get to hospital
Osteochondritis dissecans
Damage to cartilage and subchondral bone
Most commonly in knee, medial femoral condyle 70% of the time
Cause could be hereditary, traumatic, vascular
Progression: softening of cartilage
Early cartilage separation from bone
Partial detachment of cartilage
Osteo chondral separation with loose bodies
Ottawa Knee Rules for X-ray
Age 55 or older
Isolated tenderness of patella (no bone tenderness of knee other than patella)
Tenderness of head of fibular
Inability to flex 90 degrees
Inability to bear weight both immediately and in the emergency department for 4 steps
Unable to transfer weight twice onto each lower limb regardless of limping
ACL post Surgical Rehab
Quad and hamstring activation
ROM focusing on full extension
No extension you can't walk
3-4 months post surgery must proceed with caution
Graft is still weak and adapting to environment
Start with Closer kinetic chain than open kinetic chain
Close is the foot in contact with the round
Open creates shear force, knee extension must be avoided
Strengthening hamstring and quad is balanced
6 months on, increase load, jogging and running
Neuromuscular training
Return to sport, education/technique modification
Return to sport functional testing
Use a brance?
Prevention of ACL Injury, Neuromuscular Training Fifa 11
All youth athletes should do straining that work balance, proprioception and strenghtening
1/3 decrease of ACL injuries with FIFA 11
Running exercise with change of directions
Strength, plyometric and balance
End with harder intensity running
Screening for risk of knee injuries by doing drop vertical jump test
