Knee Flashcards
The patella most commonly dislocates between what ROM?
0-20deg
Between what ROM is bony instability between the patella joint maximize?
20-60deg
What 5 items make up the clinical composite score to actually detect meniscus tears?
- Hx of catching or locking
- Pain w/ forced hyperextension
- Pain with maximum flexion
- Pain or audible click with McMurray
- Joint line tenderness
What is the function of the popliteus muscle?
- Provides tibial internal rotation
- Inhibits external rotation of tibia
- Causes femoral external rotation with fixed tibia
What is a well-known sit for impingement of the ACL?
Intercondyler fossa
What is genu valgum?
Medial angle is >185deg
What is genu varum?
Medial angle is <175deg
Posterior knee pain can result in what?(3)
- knee swelling
- posterior-lateral corner involvement
- Popliteus involvement
The Ottawa knee rules, If none of the following are positive an x-ray is unnecessary?(5)
- Age >55
- Isolated tenderness to the patella (no other bony tenderness)
- Tenderness at the fibular head
- Inability to flex the knee to 90°
- Inability to weight bear immediately and in the ER
Bilateral knee pain can be caused/related by what?
1.OA
2.RA
3.systemic disease like
lupus, Lyme disease, Neurologic disease
What can cause external restricted knee joint motion?(3)
- Capsular tightness
- Scarring
- Loss of musculotendinous flexibility in muscle surrounding the joint
What can cause internal restricted knee joint motion?(3)
- Bony or meniscal block
- Loose body
- Component of surgery e.g. poorly place ligament graft or the limitation of ill fitting knee prosthesis
How is knee laxity graded?(3)
- Grade 1-1+ indicates 3-5mm
- Grade 2-2+ indicates 5-10mm
- Grade 3-3+ indicates >10mm
What insert at Gerdy’s tubercle?
- IT Band
2. Lateral condyle
What does the ACL restrict?
- Anterior Tibia translation and internal rotation
2. Can also assist preventing hyperextension
What does the PCL restrict?
1.Limit posterior displacement of the tibia on femur
Proximal and distal attachments nerve root, and action of semimembranous?
Proximal-Ischial tuberosity
Distal-Medial aspect of superior tibia
Nerve-Tibial branch sciatic N L4,L5,S1,S2
Action-Flexes and medially rotates knee, extends and medially rotates hip
Proximal and distal attachments nerve root, and action of semitendinosus?
Proximal-Ischial tuberosity
Distal-Posterior aspect of medial condyle of tibia
Nerve-Fibular branch sciatic N L5,S1,S2
Action-Flexes and laterally rotates knee
Proximal and distal attachments nerve root, and action of biceps femoris?
Proximal-Ischial tuberosity and Lateral linea aspera & Proximal 2/3 of supracondyle line of femur
Distal-Lateral head of fibula and lateral tibia condyle
Nerve-Fibular branch sciatic N L5,S1,S2 and Tibial branch sciatic N L5,S1,S2
Action-Flexes and laterally rotates knee
What ligaments, are the most common, involved w/ multi-ligaments injuries? (2)
- MCL and ACL
2. Posteriolateral corner and ACL or PCL
What causes ACL injuries? (3)
1.Noncontact
2.Happens during deceleration
and acceleration motions with excessive quadriceps contraction and reduced hamstring cocontraction at or near
full knee extension
3. Quadriceps force when combined
with knee internal rotation, a valgus load combined with knee internal rotation, or excessive valgus knee loads applied
during weight-bearing decelerating activities
What causes PCL injuries? (3)
1.“Dashboard/anterior tibial blow injury” (38.5%)
2.Fall on the flexed knee with the foot in plantar flexion (24.6%)
3.Sudden violent hyperextension of the
knee joint (11.9%).
What causes MCL injuries? (2)
- Sudden application of a valgus torque to the knee
2. Direct hit to the lateral aspect of the knee with the foot in contact with the ground
What causes isolated and combined PCL injuries?
- Isolated injury - Posterolateral directed
force to the proximal medial tibia with the knee at or near full extension, forcing the knee into hyperextension & varus.
2.Combined - Knee hyperextension,
external rotation, and varus rotation; complete knee dislocation;
-Or a flexed and externally rotated knee that receives a posteriorly directed force to the tibia
Which sports cause increased risk for ACL injuries? (2)
1.Soccer accounted for over a 1/3 of ACLR
2.Skiing injuries
-1.13 times (95% CI: 1.01, 1.27) the likelihood of isolated ACL injuries
–2 times the likelihood of PCL injuries
—2 times the likelihood of MCL and
multiligament injuries
How is postural control after ACLR according to Howells et al?
1.Postural control (single-leg stance on fixed platform with eyes open
and closed) was moderately impaired after ACLR compared to healthy controls,
What are potential risk factors for noncontact ACL injuries?(3)
- Dry weather conditions
- Artificial turf surface
- Greater posterior slope of the lateral tibia plateau
What is associated with ACL injury risk?(6)
- Female sex,
- Narrow intercondylar femoral notch size
- Lesser concavity depth of the medial tibial plateau 4.Greater anterior/posterior TFJ laxity
- Prior ACL reconstruction
- Familial predisposition
diagnosis of a sprain of the ACL and the associated
ICF diagnosis of knee stability and movement coordination impairments are made with a reasonable level of certainty when the patient
Mechanism of injury consisting of deceleration and acceleration
motions with noncontact valgus load at or near full
knee extension
• Hearing or feeling a “pop” at time of injury
• Hemarthrosis within 0 to 12 hours following injury
• History of giving way
• Positive Lachman test with “soft” end feel or increased
anterior tibial translation (sensitivity, 85%; 95% CI: 83%,
87% and specificity, 94%; 95% CI: 92%, 95%)
• Positive pivot shift test (sensitivity, 24%; 95% CI: 21%, 27%
and specificity, 98%; 95% CI: 96%, 99%)
What gives strength to the anterior horn of the medial and posterior horn of lateral meniscus?
medial meniscus-ACL
lateral meniscus-PCL
What muscle causes strain to the ACL?
Quadriceps cause anterior translation on tibia near full extension
—adds strain to ACL
What muscles relieves strain to ACL?(2)
Hamstrings and soleus creat posterior tibial translation
—relive strain on ACL
Diagnosis of a sprain of the ACL are made with the level of certainty when these follow.(6)
- MOI deceleration and acceleration motions with non-contact valgus load at or near Full knee extension
- Hearing a pop
- Hemarthrosis with in 0-12 he following injury
- Hx of giving way
- Lachman test
- Pivot shift test
Diagnosis of a sprain of the PCL are made with the level of certainty when these follow.(4)
1.Posterior directive force on the proximal tibia
-fall on a flexed knee
—sudden violent hyperextension of the knee
2.Localize posterior knee pain w/ kneeling or deceleration
3.+ Posterior drawer
4.Posterior lag sign
Diagnosis of a sprain of the MCL are made with the level of certainty when these follow.(5)
- Trauma by a force applied to the lateral aspect of the lower leg
- Rotational trauma
- Medial knee pain with valgus stress at 30° of knee flexion
- Increase separation between femur and tibia with Valgus stress at 30°
- TTP MCL
Diagnosis of a sprain of the LCL are made with the level of certainty when these follow.(4)
- Varus trauma
- Localized swelling over LCL
- TTP over LCL
- Lateral knee pain with very stressed at 0° and 30° flexion
- Increase separation between femur and tibia was very stress had 0 and 30° knee flexion
When is the posterolateral bundle of ACL taut?
When is the anterior medial bundle of ACL taut?
- Taut in extension, greatest restraint to anterior translation to about 20deg flexion
- Taut throughout flexion
What does medial or internal rotation of tibia due to ACL?
ACL becomes taut especially near full extension
What provide a stabilizing force against knee hyperextension and secondary support against the varus and valgus motion?
ACL
Patient with knee pain from OA will present with subjective and physical examination consistent of?(6)
- Age >50
- Morning stiffness <30mins
- Crepitus on AROM
- Bony tenderness
- No palpable warmth
- Boney enlargement
At what degree does the patella medial and lateral facets initially come in contact with a femur?
20deg knee flexion
When is the middle of the patella in contact with the femur?
45deg knee flexion
When is the superior third of the patella and primary contact with the femur?
90deg flexion
What happens past 90° of knee flexion with the patella?
Patella contact shift in inferiorly and laterally, loading the odd and lateral facets.
What are sensitivity and specificity for:
- JLT and McMurry
- JLT and Thessaly
- Sensitivity91% Specificity91%
- Sensitivity93% Specificity92%
JLT and Thessaly is better at detecting medial >lateral meniscus tears
Measuring effusion of the knee joint?
Grade
0-None
Trace-Milk medially sweep laterally, small amount back
1+ You can milk out the swelling and it DOES NOT return on its own but returns with the lateral sweep
2+ You milk out the swelling and it returns IMMEDIATELY TO FILL THE POUCH
3+ You cannot milk it out
What is OATS?(2)
- Osteochondral autograph transplantation
- Uses bone plugs covered with hyaline cartilage harvested from non-weight bearing services on the femoral condyle
- Used for lesions <2CM
- Contraindicated for large lesions
What is autologous chondrocyte implantation(ACI)?
1.Two-step surgical procedure involving harvesting articular Cartlidge from the patient’s knee and growing chondrocytes and implanting later
2.Indicated focal lesions 1-10 cm²
-patient failed micro fracture procedure
— failed OATS
Inclusion criteria for hip mobilization for patients with knee OA?(5)
- Hip or groin pain or paresthesia
- Anterior thigh pain
- Knee flexion less than 122 degrees
- Hip IR of less than 17 degrees
- Pain with hip distraction
