Knee Flashcards
Content: Biomechanics of Knee Extension (3)
- Tibia glides anterior
- Patella glides superior and lateral
- Fibular head anterior
Content: Biomechanics of Knee Flexion (3)
- Tibia glides posterior
- Patella glides inferior and medial
- Fibular head glides posterior
Q: What is the CPR for the knee?
flexion > extension (10:1)
Q: What is the close packed position of the knee?
Full extension
Q: What is the resting position of the knee?
30 degrees of flexion
Content: Consideration for MT
- 30-40 degrees of extension
- 15-30 degrees of extension
- 5-15 degrees of extension
- 0-5 degrees of extension
- Pure glide
- Incorporate rotation component
- Emphasize rotation
- Engage muscles/lateral hamstrings
Content: Portion of Patellar Contact During
- 0 degrees of extension
- 20 degrees of flexion
- 30-60 degrees of flexion
- 60-90 degrees of flexion
- 135 degrees of flexion
- No contact
- Inferior pole
- Mid patella
- Superior patella
- Medial and Lateral edges
Q: Where is tibiofemoral loading highest? Patellofemoral loading?
TF = stair climbing > walking/sit to stand/squat
PF = deep squats (lowest during walking)
Q: What part of the patient profile can have a large effect on the knee?
BMI and body type
Content: Routine BOS/Q’s for Aggravating Factors [used on those unwilling to talk about their problem] (8 - general idea)
- Kneel
- Sit for long time
- Sit to stand
- Squat
- Twisting
- Walk
- Running/jumping/sports related moves
- Stairs
Content: Common Descriptions - Locking (3)
- Stuck in an angle, can’t flex/extend
- Tibiofemoral (loose body/meniscus or difficulty with extension)
- Patellofemoral (loose body/meniscus or difficulty with extension)
Content: Common Description - Catching
Momentarily locking
Content: Common Description - Giving Way/Buckling (4)
- Pain or weakness?
- Tibiofemoral (ligament/mensical injury)
- Patellofemoral (tracking problem)
- Classic with ACL/meniscus problems
Content: Common Description - Crepitus/Clicking/Grinding (3)
- Joint surface changes
- Establish type and location
- Can be with or without pain
Content: Arthroscopic Grading System (Grade 0-4)
Grade 0 = normal cartilage
Grade 1 = softening and swelling
Grade 2 = Partial thickness defect, fissures < 1.5 cm diameter
Grade 3 = Fissures down to subchondral bone, > 1.5 cm diameter
Grade 4 = Exposed subchondral bone
Content: Debridgement/Chondroplasty (4)
- Removes loose flaps of cartilage
- Eliminates mechanical symptoms
- No restriction on rehab
- Short-term benefits in 50-70% people
Content: Reconstruction Options (for Femoral Condyle Injury) (3)
- Fixation of cartilage fragments
- Osteochondral autograft or mosaicplasty
- Microfracture
Term: Drilling of subchondral bone
Fixation of cartilage fragments
Term: Replace a defect cartilage in WB area with normal cartilage and bone plugs
Osteochondral autograft or Mosaicplasty
Content: Microfracture (4)
- Osteochondral drilling for bone marrow stimulation
- Protected weight bearing
- Continuous passive motion (CPM)
- Best results for acute and small cartilage lesion (2x2 cm)
Content: Carticel Transplant (for Femoral Condyle Injury( (5)
- Cell therapy to form hyaline-like cartilage
- 2-stage procedure (1–Arthroscopic to identify location and size of defect, 2–Cell transplant)
- Continuous PROM with CPM
- Prolonged protection and delayed weight bearing
- Long rehab (Protective, Slow return to function)
Q: ACL: ________________ fibers taut in flexion and _____________ taut in extension
Anteriomedial, Posteriolateral
Q: PCL: ________________ fibers taut in flexion and _____________ taut in extension
Anteriolateral, posteriomedial
Q: What is the purpose of the ACL?
Prevents anterior translation of the tibia in NWB and guides tibial rotation
Content: Gender differences for ACL injury (5)
- Increase incidence of ACL injury in females (8-10:1)
- Architecture/physiology: small intercondylar notch and female hormones (i.e. attachment less stable)
- Landing and cutting: increased valgus posture
- Motor control (Reflexive activity of hamstrings is delayed in females; control of hams prevents anterior translation of femur)
- Overall conditioning
Content: Open vs Close Chain Exercises for ACL
Close Chain = minimize shear, WB increases strain on ACL
- More functional
- Axial loading/co-contraction of quads/hams increase compression forces on the knee and decreases anterior translation/increases stablity
Open Chain = Not initially, increase resistance increases strain on ACL
- can cause too much stress on the new graft
Q: When is the most tensile force on the ACL during open chain knee extension?
Last 25 degrees
Content: consideration for ACL rehab (5)
- Limit open chain extension (90-30 degrees)
- Work on hamstring curls to reduce ACL strain
- Delay open chain extension for 8-12 wks
- Gain muscle conrol before starting open chain
- Perfom close chain in restricted range (20-60 degrees)
Content: Surgical Intervention for PCL Injury
- Precautions related to posterior tibial translation and HS strengthening
- Knee flexion > 30 degrees increases tension in PCL with open-chain
- Knee flexion > 60 degrees increases tension in PCL with closed-chain
- OKC and CKC exercises for knee flexion should be limited to 40 of flex
Q: What is the function of the MCL?
Restrains valgus and ER of the tibia
Q: What is the function of the LCL?
Restrains varus and IR(ER) of tibia
Content: Open vs Close Chain Exercise in PF Syndrome
Open: Load increases from 30-0 degrees, perform extension from 90-45
- 30-0: Quad working more, inferior pole in contact, not a lot of patellar contact
- 90-45: limiting motion increases amount of patellar contact, do LAQ over SAQ
Close: Load increases from 60-90 degrees, perfrom extension from 0-45
- Deeper squat increases load on PF joint
Content: Screw home mechanism (3)
- Happens during last 15 degrees of knee extension
- NWB = tibia ER with extension
- WB = femur IR with extension
Content: NWB Screw Home Mechanism (4)
- Tibia moving
- from 30-15 degrees = glide and rotation
- from 15-5 degrees = rotation > glide
- from 5-0 = pure rotation
Content: WB Screw Home Mechanism (5)
- Femur moving
- from 45-30 both condyles glide/roll equal distance
- from 30-15 rotation - medial moves farther posterior than lateral condyle
- from 15-5 increase in rotation at lateral knee
- from 5-0 mobility of menisci, all rotation
Content: From 15-5 degrees during WB Screw Home Mechanism (3)
- Distance between lateral meniscus and tibial plateau increases
- Increased mobility
- More of a spin movement
Q: When is it important to understand patellar contact during knee motion?
When prescribing exercises for patellofemoral syndrome
T/F: Knee joint loading is proprotional to body weight.
True
Defn: epiphysitis
Growth plate inflammation, attachment of tendon to bone
T/F: In those with chronic pain delay the patient history as long as you can.
True, their history will be long, get the information you really need first
Q: What is crepitus usually associated with?
Arthritic changes in the joint
Content: Common Descriptions - Popping
- Matters if it hurts
- Popping with injury = ligament involvement
- Popping with ADLs = arthritic changes or cavitation in synovial fluid (no big deal)
T/F: Femoral condyle injuries do not increase the risk of OA later in life.
False, do increase risk for OA
Q: What is the difference with type 1-2 and type 3-4 on the arthroscopic grading system?
1-2 = less severe
3-4 = more problematic
in regards to recovery
Q: What is the function of the meniscus? (2)
- Shock absorption
- Stability under load (secondary to ACL deficiency)
Q: Describe the vascularization of the menisci
outer 1/3 = vascularized
inner 2/3 = not vascularized
Q: Why should an ACL deficient knee not be under high load?
Will wear out menisci
Q: Which meniscus is more likely to be injured and why?
Medial, more tightly bound to tibial plateau
Q: What is the most common type of meniscal tear?
Longitudinal or bucket tear
Q: Describe the ACL and PCL distal and proximal attachment.
ACL distal = medial tibia
ACL proximal = Lateral condyle
PCL distal = lateral tibia
PCL proximal = medial condyle
Content: Functions of the ACL (4)
- Limits anterior translation of tibia in NWB
- Allows ER of tibia
- Restricts IR of tibia
- Prevent anteriorlateral instability of the knee
Content: Paterall tendon bone ACL graft (3)
- Most common
- Better initial outcomes
- Better connection with bone on bone
T/F: All grafts stretch out over time
True, graft/injured side always has more slace
Q: Which ACL graft has better long term outcomes?
Hamstring tendon graft
Q: Why is WB important early/throughout ACL rehab
To increase tensile strength of the tendon/graft
Q: What preventative measures can be taking for ACL injury? (4)
- Landing/cutting techniques
- Hamstring strength
- Eccentric Loading
- Quad to Hamstring ratio
T/F: The ACL has 50% more tensile strength than the PCL.
False, flip it
T/F: One study suggests that it may not be the patella that is tracking laterally but rather the femur that is ER from 0-30 of knee flexion that gives the appearance of patella movement.
False, IR
T/F: Squats should be an exercise for focusing on quads over glutes.
False: flip it