Lecture 6 - Knee Injuries Flashcards
1
Q
What are the 4 bones of the knee?
A
- femur
- patella
- tibia
- fibula
2
Q
Wat are the 2 joints of the knee?
A
- tibio-femoral joint
- patello-femoral joint
3
Q
What are the 4 main ligaments of the knee?
A
- medial & lateral collateral ligament
- anterior & posterior cruciate ligament
4
Q
What is the meniscus?
A
- Medial Meniscus is c- shaped - it is Semi lunar & Attaches to the MCL
- Lateral Meniscus is o-shaped - Smaller then medial meniscus, more mobile & Not attached to any structure
- Allows for a grabbing or holding tension
5
Q
What is the function of the meniscus?
A
- Deepens the Tibial surface to increase joint stability
- Spreads out the load bearing force on the joint
- Helps in the control of rotational & gliding motion at the tibio-femoral joint
- Helps circulate the synovial fluid thru the joint
- Helps to increase the load bearing area
6
Q
What are the 6 muscles acting on the knee?
A
- quadriceps
- hamstrings
- gastrocnemius
- popliteus
- tensor fascia latae (ITB)
- pes anserine complex (sartorius, gracious, semitendinosus)
7
Q
What are the general biomechanics of the knee?
A
- Extension-Flexion: 0°at Ext. to 135°at Flex
- Specific Elements of Motion: Rocking, Gliding, Rotation
- at 0° the tibia is externally rotated & in the locked home position
- 0° to 20° a rocking action takes place as the tibia internally rotates
- 20° on the tibia glides on the femur & some rotation begins
- increasing amounts of rotation up to 40 ° as the knee is flexed to 90°
8
Q
What is a valgus injury?
A
- is a lateral to medial injury, causing damage to the MCL
- medial meniscus attaches so tearing of the meniscus may also occur (McMurry test)
- if the joint is stressed far enough you may stretch the anterior cruciate (Lachmans)
- all three happening referred to as unhappy Triad
9
Q
What is a varus injury?
A
- a medial to lateral force causing damage to the LCL
10
Q
What is a hyperextension injury?
A
- anterior to posterior motion where the femur goes posterior as the tibia goes anterior
- Injured Structures Include:
- Hamstring Strain
- Posterior Capsule Sprain
- Anterior Cruciate Tear
11
Q
What is a rotational injury?
A
- Same features as a lateral to medial force
- Complications include unhappy Triad
12
Q
What is a knee sprain?
A
- when damage occurs to any of the ligaments of the knee
- a loud POPPING sound is often associated with 3rd degree sprains of any Knee ligaments
- In all injuries the severity is dependant on planting of the foot
13
Q
What is a 1st degree knee sprain?
A
- Simple stretch of the ligament, no tearing, no laxity, minimal swelling, minimal loss of strength/function
- Treatment includes Rest from sport for 7-10 days, PIER (Pressure, Ice, Elevation, Rest), Heat Modalities, ROM & Strength exercises, Proprioception exercises, Tape support & brace
14
Q
What is a 2nd degree knee sprain?
A
- Partial Tearing of the ligament, partial laxity evident, may feel solid end feel on stress tests (i.e., ligament stops you from going any further), Increased Swelling & pain, moderate loss of strength/function
- Treatment: PIER, Rest from sport 2-6 weeks, Cast/brace up to six weeks, use EMS to prevent atrophy
15
Q
What is a 3rd degree knee sprain?
A
- Complete rupture of the ligament, intense pain (initially; pain decreases due to nerve conduction loss), severe swelling, severe laxity, severe loss of function, only moderate loss of strength
- Most cases casting or bracing is done
16
Q
What is the etiology of meniscal injuries?
A
- Can be torn by medial collateral ligament with a valgus force
- Abnormal shear forces in an unstable knee i.e., post ACL tear
- Crushed when the knee is twisted while weight bearing
- The zone of tearing is important with respect to healing
- There is only blood supply to the outer third of the meniscus
17
Q
What are signs and symptoms of a meniscal injury?
A
- Joint line pain on the side of Injury
- Intra- articular pain localized to the side of injury
- Feeling of uncertainty or actual giving way
- Clicking or pop may be heard occasionally
- joint is blocked when trying to achieve extension, If locked individual will walk on toes, releases pressure in the joint
- In a long standing injury ie months, may show quads atrophy especially the VMO
18
Q
What are the surgical considerations of a meniscal injury?
A
- Torn tissue on the inner aspect of the meniscus ( the avascular zone) is often removed
- Newly torn tissue on the outer edge gets enough blood to heal properly
- Age is often the consideration on what is to be done
- The younger the athlete the more likely that a repair is attempted no matter where it is torn
19
Q
What are the 3 functions of the patella?
A
- Increases the lever arm of the quads mechanism & increases the force of knee ext
- Protection of femoral condyles from direct blows
- glides in the intercondylar groove during flexion & extension decreasing the friction on the patellar tendon
20
Q
What is a patellar dislocation?
A
- occurs when the patella slides out of its groove on the femur
- most common laterally & in females
21
Q
What are the causes of a patellar dislocation?
A
- Forced quad contraction when the knee is in about 45° of flexion & in valgus
- Genetic predisposition due to the shape of the patella
- Increased Q angle > 10° in males & > 16° in females
22
Q
What is the trauma associated with a patellar dislocation?
A
- Stretching of the medial retinaculum
- VMO or other parts of quad complex are strained
- Fractures of patella or femoral condyles
23
Q
What is the treatment of a patellar dislocation?
A
- DO NOT ATTEMPT REDUCTION! Immobilize, Ice, transport to medical care
- First time dislocation are treated conservatively
- Immobilized in straight leg position 4 –6 weeks
- Knee brace with patellar stabilizer is worn for all activities thereafter
24
Q
What should you do after immobilization of a patellar dislocation?
A
- Full treatment after immobilization includes:
- ROM exercises
- Strengthening surrounding muscle
- Correcting any biomechanical problems
- Proprioception exercises
25
Q
What is a subluxed patella?
A
- Acute or total dislocation & subsequent relocation where the athlete is uncertain of what has happened
- Most often the signs & symptoms are similar to ACL or meniscal tears
26
Q
What are the signs & symptoms of a subluxed patella?
A
- Popping sound
- Intense pain
- Knee gives away
- Rapid onset haemarthrosis (bleeding in the joint cavity)
- Athlete describes the knee joint shifted
27
Q
What is the treatment of a subluxed patella?
A
- PIER (pressure, ice, elevation, rest)
- Immobilization for a few days
- Patellar stabilization brace
- Ongoing treatment as in a first time dislocation
28
Q
What is a patellar fracture?
A
- a small break in the patella bone
- Can be caused by direct trauma or indirect trauma
- Indirect trauma refers to a severe forced contraction of the quadriceps when the knee is in flexion
29
Q
What is the treatment of a patellar fracture?
A
- If in-displaced - immobilization for 4-6 weeks
- If comminuted - surgery with wire or screw fixation
- Post immobilization - treatment is the same as a dislocation
30
Q
What is the etiology of an ACL injury?
A
- As the athletes are getting bigger, stronger & faster, there is an increased aggressiveness in the nature of how sport is played & consequently an increase in ACL injury is noted
- Female athletes are between 3-5 times more likely to suffer an isolated ACL injury compared to men
31
Q
What are 4 factors to why females suffer ACL injuries?
A
- hormonal influence
- anatomical
- neuromuscular risk factors
- biomechanical factors
32
Q
Why do hormones influence ACL injuries in females?
A
- the presence of estrogen & menstrual cycle stages suggests the ligament is more elastic at certain times of the cycle & more vulnerable to tearing
33
Q
Why does anatomical play a role in ACL injuries in females?
A
- women generally have a slightly smaller ACL than men, as well as a smaller intercondylar notch
34
Q
Why does neuromuscular influence ACL injuries in females?
A
- These include things like core stability, strength, proprioception–or inter-muscular coordination & rate of firing
35
Q
How do biomechanical factors influence ACL injuries in females?
A
- females tend to place more emphasis on their quadriceps muscle than males
- Females decelerate (cutting, pivoting and landing) in a straighter knee position putting the ACL at greater risk
- The above factors combine to give female higher impact forces during landings
- Females tend to exhibit excessive valgus stress on the knee (knees knocking inward)
36
Q
What is the MOI of ACL injuries?
A
- 90% of the injuries the foot is planted & immobile
- Hyper extension, Internal rotation of the leg with external rotation of the body
- External rotation with a valgus force at the knee
- Sudden deceleration causing hyper-extension & or rotational forces
- An anteriorly directed force to the tibia when the knee is at 90 degrees
37
Q
What are signs & symptoms of an ACL injury?
A
- Loud audible Pop or Crack is heard
- Sudden giving way of the knee and an inability to weight bear
- Rapid joint swelling ( reaches peak within first 24- 48 hours )
- Lachmans test will be positive
- MRI will often be used to confirm clinical findings
38
Q
What is the treatment of ACL injuries?
A
- rule out fracture
- PIER
- immobilize & refer to a doctor
- surgical repair is often the only option in restoring stability within athletes
39
Q
What are 3 surgical procedures of ACL tears?
A
- patellar tendon graft
- semitendinosus graft
- quadriceps tendon graft
40
Q
What is a PCL injury?
A
- When there is an anterior to posterior force to the tibia at level of the tibial tuberosity
- May occur with severe hyper-extension or hyper-flexion
- lesser disability is with this injury compared to an ACL tear
41
Q
What are the signs & symptoms of a PCL injury?
A
- Similar to the ACL, but swelling is less & there is generally very little instability in most of the cases
- Posterior drawer test for the knee is positive
- posterior Sag is generally present
42
Q
What is pre patellar bursitis?
A
- Also known as housemaids knee
- Bursa located between the skin & the patella
- Occurs as a result of a single contusion force or when there is repeated compression & shearing forces together
43
Q
What is deep infra-patellar bursitis ?
A
- Inferior to the patella between the patellar tendon & the tibia
- Becomes inflamed with direct trauma or with repeated rubbing by the patellar tendon
- Often categorized as part of jumpers knee
44
Q
What is pes anserine bursitis?
A
- located between the tendons of the sartorius, gracilis, & semitendinosus muscles & the upper medial aspect of the tibia, just medial to the tibial tubercle
45
Q
What is the cause of pes anserine bursitis ?
A
- overuse
- repeatedly pivoting from a deep knee bend
- a direct blow to the area
- Biomechanical features such as genu valgum or external tibial rotation
46
Q
What is iliotibial band friction syndrome?
A
- caused by overuse, mostly due to errors in training, b y people who exercise vigorously
- Sudden changes in surface, speed, distance, shoes, & frequency can break down the body faster than it can heal
- The overuse creates stress that the body cannot repair, & soft tissue breakdown occurs
- When the band is excessively tight or stressed, the ITB rubs more vigorously
47
Q
What is the cause of iliotibial band syndrome?
A
- Limb length discrepancy, Genu varum, Over pronation, Hip adductor weakness, Myofascial restriction, Tight tensor fascia lata & gluteus max
48
Q
What is patellar tendonitis?
A
- Also known as jumpers knee
- overuse problem, with pain in one or more of the following regions:
- Inferior pole of the patella - Mid tendon region - Insertion at the tibial tubercle
49
Q
What is the cause of patellar tendonitis?
A
- Intense running, Jumping, Frequent starts & stops, Squatting, Kneeling, over-pronation in the running or walking gait, running on hard surfaces, rapid increase in running & change in running surfaces
50
Q
What is quadriceps tendonitis?
A
- Another of the problems broadly classified as jumpers knee
- cause is similar to patellar tendonitis except the pain manifests at the superior pole of the patella where the quadriceps tendon inserts
51
Q
What is patello femoral arthralgia (PFA)?
A
- onset of pain in the patello-femoral joint due to mal tracking of the patella on the femur
- Common in running & jumping athletes
- Pain increases with going up & down stairs
- Positive Theater Sign ( ie pain increase & difficulty getting when sitting for long periods)
52
Q
What is the cause of patello femoral artralgia (PFA)?
A
- Attributed to chronic mal tracking of the patella in the trochlear groove
- Secondary to inappropriate treatment or improper rest after a deep contusion
- Biomechanical issues such as overpronation
53
Q
What is chondromalacia patella?
A
- Specific degenerative changes of the articular hyaline cartilage of the patella
54
Q
What is the treatment for overuse injuries?
A
- Controlled Rest is the Key to a positive outcome
- Ice & heat as required to help pain symptoms
- Correct biomechanical issues & Muscle imbalances
- Improve all knee muscle flexibility
- Using support & patellar stabilizing brace
55
Q
What is osgoode-schlatter disease?
A
- An avulsion injury of the patellar tendon from the apophysis at the tibial tuberosity
- Seen often in highly active adolescents between ages 10 -15 years old
- Most prevalent in 12 -15 year old males
56
Q
What is the etiology of osgoode-schlatter disease?
A
- the bone grows in length & the muscle is then stimulated to lengthen
- the muscle does not respond to the growth fast enough & coupled with strenuous activity & the increasing traction may lead to avulsion injury
- A direct contusion to the Tibial tuberosity may also cause inflammatory changes over the tibial tuberosity
57
Q
What is Larsen-johansson syndrome?
A
- Injury that Involves the patellar tendon at the attachment on the inferior pole
- inflammation & irritation of the growth plate at the distal end of the patella
58
Q
What is osteochondritis?
A
- The area of bone just under the cartilage surface is injured leading to damage to the blood vessels of the bone
- leads to avascular necrosis of the area
- dead bone can be seen on an X-ray & is sometimes referred to as the osteochondritis lesion
- If the hyaline cartilage breaks off then we have an osteochondritis dessicans
