Week 1: Knee & Ankle Flashcards
Do ACL injuries generally occur as a result of contact or non-contact mechanisms?
- Non-contact
What other concomitant knee pathology generally occurs with an ACL injury?
- Meniscus
- Chondral injury ie damage to the articular cartilage
- Collateral ligament
To what extent does an ACL injury increase the risk of future knee OA?
40-70% increased risk of knee OA
What signs on an MRI would suggest an ACL tear? 5*
- Increase in fluid around the ACL (subsequently there is increased T2 signalling)
- Fibre discontinuity
- Abnormal ACL orientation (ie if the ACL is less steep)
- Empty notch signal: ACL will still attach to tibia but won’t attach to the lateral femoral condyle (generally this area fills with fluid as a result)
- Bone contusions
An ACL rupture should always be suspected if the patient reports (3):
- An injury mechanism that involves deceleration/acceleration in combination with a knee valgus load eg a lateral movement with the knee bending in
- Hearing or feeling a “pop” at the time of injury
- hemarthrosis within 2 h of injury (bleeding into a joint space)
Do males or female have a higher incidence of ACL injury?
Males (higher participation rate in soccer, AFL, etc)
Although this rate is growing particularly in young females (aged 5-14)
What is the most common traumatic knee injury?
ACL
Do males or females have a higher risk of ACL injury?
3.4 fold greater risk in females than males
Modifiable risk factors for ACL injury
- Earlier/more intense and more frequent participation in sport
Non-modifiable risk factors for ACL injury
Variation in bone morphology
Neuromuscular control
Genetic eg amount of knee extension
Hormonal
KANON trial:
- Early rehab + early ACL repair
- Early rehab + optional delayed ACL repair
What were the findings (also 5 year follow-up findings?)
Rehabilitation plus early ACL reconstruction was not superior to a strategy of rehabilitation plus optional delayed ACL reconstruction.
At 5 years the results didn’t differ better surgically reconstructed early vs late. Note: KOOS was used as the primary outcome measure.
Compare trial
- Randomised to early ACL reconstruction
- Rehabilitation followed by optional delayed ACL reconstruction after a three-month rehab period
Larger improvement at two-years in the early surgical reconstruction group that was statistically significant but unclear if the difference was clinically meaningful.
50% of patients randomised to three-months of rehab did not need surgery.
Note: IKDC subjective knee form
SNAPP trial
- Initial rehabilitation
- ACL reconstruction
This trial found better 18-month outcomes in participants assigned to ACL reconstruction than in those assigned to rehabilitation and optional delayed reconstruction
ACL cross bracing protocol results
Why is the knee flexed?
- 90% of patients had evidence of healing on 3-month MRI (continuity of the ACL).
- More ACL healing on 3-month MRI was associated with better outcomes.
- Longer-term follow-up and clinical trials are needed to inform clinical practice
The more flexed the knee is the more likely the ACL is to mesh & recover. Knee is braced and held at 90 degrees (NWB)
When are allografts used in ACL repair? Benefits/consequences?
Most commonly used for revision ACL surgery
- No pain occurs in autografts
- Decreased surgery time, incision, stronger bone fixation
- Increased risk of infection and increased risk of failure
Benefits/consequences of using a patella tendon graft?
- increase in patellofemoral knee pain
- Increase in post-op stiffness
- Decreased knee laxity compred to other methods
Note: middle 1/3rd of tendon is utilised
Benefits/consequences of using a hamstring tendon graft?
- Decreased knee pain stiffness
- Decreased hamstring strength
- Decreased incision and faster recovery
- Increased laxity/potential graft lengthening
Note: Easy surgery to perform
Benefits/consequences of using a patella tendon graft?
- Fixation not as solid
- Increased knee pain post op
- Decreaed laxity compared to other methods
ACL: post management
- Continuous passive motion …. improve long term motion.
- Early (Immediate) weightbearing …… patellofemoral pain, prevent …… & return the ….-…. mechanism (E)
- Postoperative rehabilitative bracing did not improve ….., pain, ……, or safety.
- Did not
- Decreases patellofemoral pain
- Prevents atrophy
- Returns the screw-home mechanism
- Swelling & ROM
What is the most significant meniscal damage that can occur? What will happen to the knee as a result?
Bucket handle
- Knee will be completely locked and unable to extend (emergency MRI will likely be needed)
Big hole in the actual meniscus as opposed to most others that are generally tears
What are the types of meniscal tears?
- Vertical
- Transverse
- Peripheral
- Bucket-handle
- Parrot beak
- Flap
General presentation of a meniscal tear - what are the symptoms?
- Pain, stiffness & joint effusion
- Catching/locking/ROM restriction
- Instability
What is involved in meniscus surgery?
- Arthroscopy + meniscectomy: damage cartilage is trimmed away
- Arthroscopy + meniscus repair: sutured together. Depends on type of tear, location of tear (outer not inner - outer is more likely to heal?, condition of meniscus and time for recovery is longer than meniscectomy
Note: arthroscopy involves using a camera to look at the knee joint.
Is criteria or time based progression preferred in traumatic knee injury?
Combination of both but must definitely being criteria based goals
