Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Kin 2236 Athletic Injuries > (3) Lecture 15: Knee 2.0 > Flashcards

(3) Lecture 15: Knee 2.0 Flashcards

1
Q

Medial Support Complex Layers

A

3 layers

Superficial: Sartorius and fascia
Middle: superficial MCL and semimembranosus
Deep: deep fibres of MCL and capsule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Medial Support Complex Stability

A

Primary stabilizer: MCL - 25 to 30 degrees
- ACL/PCL secondary

Bony structure is tertiary support

Muscles help in full extension
- medial hamstrings (sartorius, semimemb, semitend.)
- medial head of gastrocs
- quad muscle - vastus med.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

MCL Components

A

CAPSULAR = swelling

Has superficial and deep components
- deep: connect directly to medial meniscus
- superficial: run from medial femoral epicondyle to superomedial surface of tibia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Contribution by Structure to Medial Knee Injuries

A

AT 25 degrees
- most from superficial MCL then crucoiates

AT 5 degrees
- most from superficial MCL (less than at 25) then post capsule then cruciates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Anatomy of ACL

A
  • runs from anterior aspect of tibial plateau to posterior medial aspect of lateral femoral condyle

2 major bundles named for attachment on tibia:
- anteromedial - tighter in FLEXION (heat-sensitive)
- posterolateral - tighter in EXTENSION

PRIMARY RESTRAINT TO ANTERIOR TIBIAL TRANSLATION

greatest translation at 20 - 30 degrees

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Stabilizing role of ACL

A

WEAKER of two cruciates

  • restricts POSTERIOR translation of FEMUR relative to tibia during WEIGHT BEARING
  • restricts ANTERIOR translation of TIBIA during NON-weight bearing
  • also limits excessive rotation of tibia

secondary support for VALGUS and VARUS w/ collateral lig. damage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Heat sensitive view of ACL

A

anteromedial bundle tightens in FLEXION
posterolateral bindle tightens in EXTENSION

WHITER = MORE ON STRETCH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Anatomy of PCL

A
  • originates on lateral aspect of medial femoral condyle and inserts posteriorly to intercondylar area of tibia

2 major bundles named for attachment on tibia:
- anterolateral: tight in FLEXION (larger)
- posteromedial: tight in EXTENSION

LARGER AND STRONGER than ACL

  • primary restraint to POSTERIOR tibial translation
  • GREATEST translation at 20-30 degrees
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Stabilizing role of PCL

A

STRONGER of cruciate ligs

  • restricts anterior translation of femur relative to the tibia during weight beating (foot planted)
  • restricts posterior translation of tibia during NON-weight bearing
  • limited HYPER-INTERNAL ROTATION
  • secondary support for valgus + varus w/ collateral lig damage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Collaterals supports

A

Lateral primary support = MUSCLES
Medial primary support = MCL

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Meniscus

A
  • once believed to be a useless remnant of intra-articular attachments
  • stabilize knee by increasing concavity of tibia

Shock absorption
- full extension (45-50% of load)
- 90 degree flexion (85% of load)
- compression facilitates distribution of nutrients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Medial vs Lateral Meniscus

A

Medial Meniscus - LOTS of issues (more injured)
- C-shaped
- larger radius of curvature
- tight connection w/ capsule + MCL
- POOR MOBILITY
- ex. Tutanic

Lateral Meniscus - less injured but more CATASTROPHIC
- O shape
- smaller radius of curvature
- attached loosely to capsule + POPLITEAL TENDON
- increased mobility
- ex. speedboat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Meniscal Fixation

A
  • menisci are fixed in place + prevented from extruding by CORONARY ligaments and anterior + posterior transverse meniscal ligaments
  • deep portion of capsule attached to periphery of mensicus
  • medial is THICKER/TIGHTER than lateral
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Meniscal Blood Flow

A

Divided into 3 zones:
- RED zone: good blood supply - outer 1/3
- RED-WHITE zone: minimal blood supply - middle 1/3
- WHITE zone: avascular

Outer injuries heal better b/c of good blood flow
Inner injuries are usually cut out b/c they won’t heal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Subjective Knee Assessment

A

Area of pain - medial, lateral, internal?

Mechanism of Injury
- Varus or Valgus (valgus: hit on outside + stretch inside)
- Contact or non-contact (if non-contact: decelerating, cutting, landing?)

Sounds (i.e. “pop” or “crack”)

Continue to play/able to weight bear (WB)?

Locking (meniscal), giving way since (ligamentous, muscle, etc)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Knee Swelling - Subjective Assessment

A

Nature of swelling - hemarthrosis?

Noticeable swelling 2-6 hours post-injury
- >75% of adults - ACL tear
- Young (13-14) most common is patellar dislocation
- Pediatrics - suspect patellar dislocation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Hemarthrosis

A

Fast swelling
- bleeding into joint
- typically occurs more quickly than synovial effusion/capsular swelling

Ex. ACL, red-red mensicus, patellar dislocation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Ottawa Knee Rules

A

Knee X-Ray is ONLY needed for knee injuries w/ any of these findings:
- age 55 or older
- isolated tenderness of patella (no other bone tenderness)
- tenderness of head of fibula (2-3 in. lateral from tib. tuberosity)
- cannot flex to 90 degrees
- unable to bear weight for 4 STEPS (unable to TRANSFER WEIGHT TWICE onto each lower limb regardless of limping)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Subluxed or Dislocated Patella

A

generally dislocates LATERALLY

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Acute Patellar Dislocation MOI

A
  • forceful knee rotation (tibia ER/femur IR) +/- forceful quad contraction
  • knee usually near full extension (out of trochlea) - patella moves UP in extension
    +/- laterally directed force
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Symptoms of Patellar Dislocation

A
  • may report feeling knee “shift”, “move” or “pop out”
  • LOTS OF PAIN UNTIL REDUCED
  • FAST swelling = hemarthrosis
22
Q

Signs of Patellar Dislocation

A
  • loss of knee function (if still dislocated)
  • tenderness over MEDIAL border of patella
  • POSITIVE LATERAL APPREHENSION TEST

NEED TO R/O ACL –> b/c of similar subjective findings - hemarthrosis, shift/move/pop

23
Q

Patellar Dislocation Treatment

A

Slightly FLEX HIP and slowly EXTEND THE KNEE
- takes tension off quads - easier to reduce
- usually patella relocates. If not, do NOT force the patella medial

send for X-rays immediately

24
Q

Lateral Support Complex

A

3 layers
Superficial: ITB and biceps femoris
Middle: patellofemoral ligs and retinaculum
Deep:
- LCL
- popliteus tendon
- capsule

MAIN SUPPORT FROM MUSCLES

25
Q

LCL

A
  • injuries are less common but more complicated
  • usually VARUS (force on medial side) loading +/ hyperextension
  • most contribution at 20-30 degrees of knee FLEXION
  • may include ITB, lateral hamstrings and/or popliteus
26
Q

Varus force vs valgus loading

A

Varus loading - force on medial side
Valgus: hit on outside + stretch inside

27
Q

MCL Facts

A
  • 40% of all severe knee injuries involve MCL
  • MOST FREQUENTLY INJURED knee structure
  • VALGUS force +/- rotation
  • often occurs in ISOLATION (unlike lateral)
28
Q

Signs and symptoms of collateral ligament sprains

A

reports of pain over structure

Swelling? Timing?
- slow localized swelling on medial side (grade 2+) – capsular effusion > 8 hrs

Stress testing: in SAME DIRECTION of MOI
- valgus stress for MCL and varus stress for LCL
- Grade 1: pain w/ no laxity
- Grade 2: pain w/ laxity; distinct endpoint
- Grade 3: pain variable; gross laxity; no endpoint

29
Q

ACL injuries

A
  • can be contact or non contact (60-80% non-contact)

usually during cutting or single leg landing
- may occur in isolation or in combo w/ other injury (75% have meniscal injury; 80% have bone bruise on lateral jt line or Segond Fracture)

2-8x higher injury rate in females

30
Q

ACL MOI

A
  1. Valgus after MCL - usually w/ contact
  2. Deceleration/internal rotation - non-contact
  3. Quads Active - anterior tibial translation (quads fire more than hamstrings - more common in FEMALES)

NOT hyperextension - doesn’t happen in isolation

31
Q

Quads Active ACL MOI

A

no co-contraction from hamstrings

Main mechanisms
- rapid deceleration
- untoward landing

anterior tibial dislocation by quads

32
Q

Symptoms of ACL injury

A
  • 80% describe an audible “pop” or “crack”
  • can range from very painful to minimal pain
  • usually unable to continue activity
  • HEMARTHROSIS (>75% –> 1-6 hours)
  • may report instability or giving way
33
Q

Signs of ACL injury

A
  • restricted movement - especially extension
  • lateral joint tenderness - often mistaken for LCL (80% have lateral bone bruise or Segond Fracture)
  • POSITIVE ANTERIOR DRAWER + LACHMAN’S TEST (LACHMAN > ANT. DRAWER)
  • Lachman @ 20-30 degrees of flexion
34
Q

PCL Injuries

A
  • STRONGEST of knee ligaments
  • only 1 in 10 cruciate injuries involve PCL
  • 60% include injuries to other structures
  • usually sports injuries but also common in MVAs
35
Q

PCL MOI

A

Most common: DIRECT BLOW to upper portion of tibia
- fall on flexed knee
- MVA - dashboard injury or pre-tibial trauma

Hyper-flexion
- increased tension in anterior segment
- impinged btwn posterior tibia + intracondylar notch roof

Hyperextension

36
Q

Signs of PCL Injury

A
  • MINIMAL swelling
  • POSTERIOR DRAWER test = most sensitive
  • SAG TEST will be positive
  • assess medial and lateral structures too
37
Q

Malalignment Syndromes/Overuse Knee Injuries/Patellofemoral Pain

A
  • tendinosis
  • osteoarthritis
  • runner’s knee
  • chondromalacia
  • ITB friction syndrome
  • Patellofemoral Pain Syndrome
  • jumper’s knee
38
Q

PFP

A

Patellofemoral Pain

  • pain in peripatellar/retropatellar area that is aggravated by at least one activity that loads the patellofemoral jt during weight bearing on a flexed knee
  • pain walking down stairs
  • pain with squatting
  • pain following sitting for long periods
  • running, jumping, hopping

patients w/ PFPS are 10-25% of PT visits

39
Q

Causes of PFP

A
  • HYPO-pressure on medial aspect of patellofemoral jt
  • HYPER-pressure on later aspect
  • results in cartilage degeneration from inside-out
  • results in cartilage rub and fibrillation
40
Q

Proposed contributing INTRINSIC factors

A
  1. Lower chain alignment
  2. Excessive pronation
  3. Poor multi-plane lumbo-pelvic/pelvo femoral control (core, glut. medius)
  4. Shortened muscles: hamstrings, ITB, calves and rectus femoris
  5. Pull of quads
41
Q

Lower Chain alignment and PFP

A

VALGUS alignment is common for PFP

Load bearing axis on outside = pushing in (knocked knees)

42
Q

Q-Angle

A
  • axis formed by femur and tibia
  • greater Q angle = greater lateral pull
  • Q angle > 20 degrees = increased risk of instability of PF jt
  • can be factor in PFPS, OA, ITB friction syndrome (varus)
43
Q

Medial Collapse Mechanism

A

poor multi-plane lumbo-pelvic/pelvo femoral control

  • hip adduction, femoral internal rotation and knee valgus (lateral pull on patella)

change femur under patella
- less joint contact area
- more joint stress

44
Q

Shortened muscles

A

Tight muscles crossing the knee may cause altered function

Quads, hamstrings, ITB, triceps surae

45
Q

Shortened quads

A

increased compression of PF joint during physical actibity

46
Q

Shortened hamstrings

A

antagonist to quads

will need increased quads force production to overcome length issue

47
Q

Shortened ITB

A

lateral influence on patella = more pressure over lateral surface of trochlear groove

must move over femoral condyle at 25-30 degrees flexion

48
Q

Shortened triceps surae

A

triceps surae: gastrocs + soleus

limit ankle dorsiflexion, which is often compensated for by excessive rotation of lower leg
- altered Q angle

49
Q

Vastus medialis dysfunction

A
  • sum of all 4 quads and tibial tendon are set into valgus
  • theory that weak VMO will not be able to maintain alignment

causes abnormal pull on patella - overloading lateral side

50
Q

PFP Treatment

A

Initial phase
- PEACE & LOVE/POLICE
- palliate pain, decrease swelling, identify training issues

Repair phase - correct biomechanical issues
- look at muscle length, strength and function

Remodeling phase
- slowly increase training frequency and intensity

51
Q

Evidence Based Tips for PFP Rehab

A
  • prescribe daily exercises of 2-4 sets of 10+ reps over a period of 6+ weeks
  • consider higher reps for PFP patients who do lots of running and jumping
  • conflicting research about knee braces and oatellar taping
  • some evidence for prefabricated foot orthoses w/ regard to reducing short term pain

Kin 2236 Athletic Injuries (20 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions