LE: Knee Flashcards
1
Q
Palpation of the knee - Posterior
A
- Popliteal fossa
– *Popliteal artery is only palpable structure
normally in this area - Abnormal bulges
- Popliteal artery aneurysm
- Popliteal thrombophlebitis
- Baker’s cyst
2
Q
Distal Femoral Fractures etiology
A
Trauma
3
Q
Distal Femoral Fractures clinical presentation
A
- Severe pain, distal thigh
- Acute trauma in the history
- Unable to ambulate
4
Q
Distal Femoral Fractures diagnosis
A
- Assess distal neurovascular status
– Ankle-Brachial Index obtained if any vascular injury
suspected - Abnormal results = (ABI < 0.9)
- X-ray
– Femur: AP & lateral
– Knee: AP, lateral - Possibly Oblique or tunnel view of the knee
- Consider CT or MRI if high suspicion for an occult knee
fracture despite (–) X-ray
– CT angiography can be performed concurrently, if vascular
injury suspected.
5
Q
Distal Femoral Fractures
Management
A
- ER
- Hospital admission
- ORIF
- If the fracture is non/minimally displaced
could be managed non-surgically
6
Q
Distal Femoral Fractures complications
A
- Early
– Neurovascular injury
– Compartment syndrome
– Infection - Late
– Chronic pain
– Nonunion or malunion
– Infection
– Thromboembolic disease
7
Q
Tibial Plateau Fractures etiology
A
- Low energy injuries
– patients > 50 years old > 50% of
tibial plateau fractures - High energy injuries
– Any age - MVA, Fall from height
- 1.3% of all fractures
- 8% of fractures in the elderly
8
Q
Tibial Plateau Fractures
Clinical Presentation
A
- Proximal tibia pain & swelling
- Abrasions, lacerations from trauma
- Open wounds
- Unable to bear weight
- Joint effusion
9
Q
Tibial Plateau Fractures diagnosis
A
- X-ray – AP, Lateral, Oblique
- CT – Aids in surgical decision making and planning
- MRI – When ligament or meniscus injury also suspected
- Assess for compartment syndrome
– perform serial leg compartment exams for
minimum 24 hours
10
Q
Tibial Plateau Fractures management
A
- Stable, minimally displaced fractures may be treated conservatively with splint, long
leg cast, or cast brace for 8-12 weeks - Surgical management
– Intra-articular fractures with > 2 mm joint depression or separation
– Significantly displaced metaphyseal components or angulated > 5°
– Fractures with vascular injury
– Fractures with associated ligamentous injuries requiring stabilization - Open fractures
– Antibiotic prophylaxis
– Update tetanus status
– Consider deep vein thrombosis prophylaxis
11
Q
Tibial Plateau Fractures
Complications
A
- soft tissue bruising or swelling
- compartment syndrome
- knee stiffness (may be due to initial injury, surgery, scarring, or immobilization)
- infection
- osteoarthritis (2° to initial chondral damage, residual articular discontinuity, or
postoperative disrupted mechanical axis) - malunion or nonunion
- wound dehiscence
- deep vein thrombosis (DVT)
- peroneal nerve injury
- avascular necrosis of articular fragments
- loss of limb
12
Q
Patella Fracture etiology
A
- Direct blow- Trip and fall
landing on knee - Fall onto knee
- Forceful contraction of the
quadriceps
13
Q
Patella Fracture
Clinical Presentation
A
- Focal patellar pain
- Soft tissue swelling anterior to & around patella
- Knee joint effusion (typically = hemarthrosis)
14
Q
Patella Fracture diagnosis
A
- X-ray
– AP, Lateral, Sunrise
15
Q
Patella Fracture
Management
A
- Isolated patellar fractures can be managed as an outpatient
– nondisplaced fractures (< 3 mm of fragment of fracture separation & < 2 mm of
articular incongruity) with intact knee extensor mechanism
– except open fractures - Consult ortho for patellar fractures needing potential operative repair
– Including comminuted & open fractures
16
Q
Patella Fracture
Complications
A
- Patella tendon rupture
- Quadriceps tendon rupture
- Non- & mal-union
- Delayed union
- Posttraumatic patellofemoral joint arthritis
17
Q
Knee Dislocation etiology
A
- High Energy Trauma
– MVA, Pedestrian v auto, Fall from height
18
Q
Knee Dislocation presentation
A
- Significant deformity
- Significant instability
- Non-ambulatory
19
Q
Knee Dislocation
Diagnosis
A
- Check distal neurovascularity
– Assess popliteal artery
– Vascular injuries requiring operative repair- Can be a vascular emergency - Evaluate of ligamentous injury
– Anterior drawer, Lachman, Varus/Valgus, Posterior Drawer - X-ray
– AP, Lateral - CT + CT angiography - Angiography added to look at the vasculature
– However, do not delay operative repair to perform CT angiography
20
Q
Knee Dislocation
Management
A
- Orthopaedic & potential a vascular emergency
- Closed reduction with procedural sedation (←Click for link) 1:55
- Posterolateral dislocations typically will require open reduction
- Once reduced, immobilize the lower extremity in a hinged knee brace/splint at 20
degrees of flexion to prevent further injury - It is estimated that up to 50% can self reduce- Knee can look OK, but damage is
already done, thus making it easy to miss
21
Q
It is estimated that up to 50% can self reduce
A
Knee dislocation
22
Q
Knee Dislocation
Complications
A
- Vascular injury occurs in 5%-43% of knee dislocations
– Popliteal artery injury - Posterior knee dislocations
- Other vessels that may be affected:
– medial genicular artery, anterior tibial artery, posterior tibial artery, superficial
femoral artery, & common femoral artery - Thrombosis, particularly deep vein thrombosis
- Arterial limb ischemia
- Peroneal nerve injury
- Compartment syndrome
- Instability
23
Q
Patella Dislocation etiology
A
- patella dislocates laterally in response to force or blow
- indirect trauma is usual cause
– typically occurs as femur rotates internally while leg is in valgus & foot planted
– tension applies lateral forces on patella
24
Q
Patella Dislocation
Clinical Presentation
A
- History of trauma with sensation of slippage &
intense pain
– typically occurs during sports or other intense
physical activity - Unable to bear weight & ↓ range of motion
- May have impaired muscle activation & strength
- “catching” or “locking” of knee suggests presence
of loose bodies
25
Q
Patella Dislocation
Diagnosis
A
- History
- Clinical
– Patellar hypermobility & apprehension when shifted laterally
– Bassett’s sign FYI
– Moderate to severe effusion - X-ray, CT, or MRI to help identify contributing anatomic conditions or potential
complications, including medial patellofemoral ligament (MPFL) tear
26
Q
Bassett’s sign
A
- Pain on palpation of medial patellofemoral ligament (MPFL), patellar, &
peripatellar areas - Pain at full extension, and then resolves when knee at 90 degrees
27
Q
Patella Dislocation
Management
A
- Manual closed reduction may be performed under mild sedation by applying gentle force to the lateral aspect (medial direction) of patella while gradually extending the knee
- RICES
- Immobilize patients for 4 weeks in straight knee brace; use knee brace to stabilize
affected area as soon as pain allows - Physical Therapy with increase gentle ROM
- Surgery
– Typically not required
28
Q
When may surgery be indicated for a patella dislocation?
A
- disrupted medial patellofemoral ligament (MPFL)
- continued instability & poor outcomes following
conservative management - osteochondral defects
- ≥ 1 risk factors for instability in uninvolved knee
- aged < 15 years old with desire to return to
high-level sports or physical activities
29
Q
Patella Dislocation complications
A
- recurrent patellar dislocation
- patellofemoral osteoarthritis
30
Q
Medial Collateral Ligament Sprain etiology
A
- Common in sports
- Direct valgus stress from a blow to the lateral aspect of the knee
– Direct blows typically cause more severe injury - Indirect stress through abduction or rotation of the lower leg
– Twisting & torque of the lower extremity
31
Q
MOST COMMON KNEE INJURY
A
Medial Collateral Ligament Sprain
32
Q
Medial Collateral Ligament Sprain presentation
A
- Many able to ambulate
- Medial swelling & ecchymosis
- Joint stiffness
- Pain
33
Q
Medial Collateral Ligament Sprain diagnosis
A
- History
- Physical Exam
– + Valgus stress test
– Focal tenderness over medial joint line - MRI
– Definitive Diagnosis - Grade 1, 2, or 3
34
Q
Medial Collateral Ligament Sprain
Management
A
- RICES
- Temporary bracing, but avoid long term immobilization
- Physical Rehabilitation
– Early ROM
– Weight bearing to tolerance - Surgery is rarely necessary
– Usually reserved for multiple injuries (ie Unhappy triad)
35
Q
Medial Collateral Ligament Sprain
Complications
A
- Persistent instability
- Residual pain
– Rarely Complex Regional Pain Syndrome - Arthrofibrosis- stiffening of the knee from excessive collagen production, adhesion
and scar tissue build up of a joint
36
Q
Lateral Collateral Ligament Sprain etiology
A
- Associated with injuries to the posterolateral corner (PLC), posterior cruciate ligament (PCL), &/or anterior cruciate ligament (ACL)
- Most common mechanism of injury involves a high energy force that combines hyperextension & varus forces
- Injury may occur with an isolated varus hyperextension or external tibial rotation
force - Typically, an isolated LCL injury, especially of lower grade, is caused by a primarily varus force (eg, knee forced laterally from a blow to the medial side
37
Q
Lateral Collateral Ligament Sprain clinical presentation
A
- Patients typically present following a blow to the medial or anteromedial aspect of
their knee while it was fully extended, & report lateral or posterolateral knee pain. - Swelling
- “Locking or catching” (if meniscus is involved)
- Knee buckling
38
Q
Lateral Collateral Ligament Sprain diagnosis
A
- History
- Physical exam
– + Lateral collateral ligament tenderness
– + Varus stress test - MRI
– Definite diagnosis - Grade 1, 2, & 3
39
Q
Lateral Collateral Ligament Sprain
Management
A
- RICES
- Grade 1 – Crutches for ~week prn for pain control; hinged bracing 4-5 weeks
- Grade 2 – Crutches & knee immobilizer for 1-3 weeks for pain control
– A hinged brace may be used once the patient is partial-weight-bearing, usually at
two to three weeks. - Grade 3 – Immobilization, non-weight-bearing with crutches, & consultation with an
orthopedic surgeon.
– Immobilization will likely be maintained until surgery is performed, preferably
within two weeks of injury. - Acute lateral collateral ligament (LCL) partial tears with functional instability or injuries
of the posterolateral corner should be referred to an ortho within 2 weeks - Acute, mid-portion, complete LCL tears
40
Q
Lateral Collateral Ligament Sprain
Complications
A
- Functional instability
- Peroneal nerve injury
41
Q
Anterior Cruciate Ligament Sprain etiology
A
- Contact injuries account for ~30% of ACL injuries
- Noncontact injuries account for ~70% of ACL injuries
42
Q
Anterior Cruciate Ligament Sprain
Clinical Presentation
A
- Patients report a “pop” at time of injury,
immediate pain & swelling of knee - Joint effusion
43
Q
Anterior Cruciate Ligament Sprain
Diagnosis
A
- Assess neurovascular status
- Joint line tenderness
- Effusion
- Varus & Valgus laxity (0°, 30° of flexion)
- Lachman test
– 86% sensitivity
– 91% specificity
- Lachman test
- Pivot shift (typically most accurate under
anesthesia because it hurts)
– 97-99% specificity
- Pivot shift (typically most accurate under
- MRI
44
Q
Anterior Cruciate Ligament Sprain
Management
A
- Acute Phase
– RICES - Surgical Management
- Knee bracing
45
Q
Anterior Cruciate Ligament Sprain
Complications
A
- ↓ knee function
- Sports “disability”
- Arthrosis
- Osteoarthritis, early onset
46
Q
Posterior Cruciate Ligament Sprain etiology
A
- Isolated PCL injury is rare
– Commonly associated with posterior lateral corner injuries, ACL injuries & MCL
injuries. - High energy trauma
– MVA - Dashboard injury (posterior force)
- Sports, falling on the knee with a plantar flexed ankle
47
Q
Posterior Cruciate Ligament Sprain
Clinical Presentation
A
- Pain
- Swelling/Effusion
- Knee instability
- Posterior Drawer (or Sag sign)
48
Q
Posterior Cruciate Ligament Sprain
Diagnosis
A
- History
- Physical exam
– + Posterior Drawer - MRI
- Arthroscopy
49
Q
Posterior Cruciate Ligament Sprain
Management
A
- RICES
- Hinged knee brace
– Locked in full extension x 2 weeks - Physical Rehabilitation
- Surgical management
50
Q
Surgical management for PCL sprains
A
– Grade 3 PCL injuries – Anterior border of medial tibial plateau can be displaced
posteriorly beyond the anterior border of the medial femoral condyle (posterior
displacement >10 mm
– PCL injuries associated with any fracture or any additional soft tissue injuries of
significance (eg, posterolateral corner, ACL injury, meniscal tear).
– PCL disruption involving avulsion of the ligamentous insertion at the tibia
51
Q
Posterior Cruciate Ligament Sprain
Complications
A
- Generally good prognosis in isolated tears
- Degenerative joint disease
- Pain
52
Q
Meniscus Injury
Etiology
A
- Acute meniscal tears = shearing/compressive forces on a meniscus
– Most often due to noncontact forces, involving sudden acceleration or deceleration coupled with a directional change
– Contact injuries, with varus or valgus forces acting on knee
– Tibial displacement, due to injury to anterior cruciate ligament (ACL) &/or medial collateral ligament, leading to undue stress on meniscus - Degenerative meniscal tears
– With age menisci become stiff, & have ↓ compliance
– Result from repetitive normal forces on a deteriorated meniscus
53
Q
Meniscus Injury
Clinical Presentation
A
- Knee pain
– especially with deep knee flexion - Effusion (acute)
- Patient reports ”locking, popping, catching, or buckling”
– Especially with using stairs - Persistent focal joint line tenderness
- ↓ ROM
54
Q
Meniscus Injury
Diagnosis
A
- History
- Physical Exam
– + McMurray Test
– Sensitivity = 22-70%, Specificity = 29-96%
– +Thessaly Test (Thessaly Test Video) - Medial meniscus
– Sensitivity = 89%, Specificity = 97% - lateral meniscus
– Sensitivity = 92%, Specificity = 96% - MRI
55
Q
Meniscus Injury
Management (conservative)
A
- Conservative (no associated ligament tears)
– Degenerative meniscal tears
– Nonsymptomatic, nondisplaced meniscal tears
– Poor surgical candidates (multiple comorbidities or advanced age)
– Acute traumatic meniscal body tears - Modify activity, & utilize crutch ambulation
- Simple knee sleeve may be used to manage swelling
- Physical Rehabilitation
– Bracing in patients with meniscal root tears
– NSAIDS &/or corticosteroid injections
56
Q
Meniscus Injury
Management- Surgical
A
– Younger patients
– Bucket Handle Tears lend themselves to surgery sooner rather
than later (eg. Often meniscus surgery is done after PT)
– Failure of conservative management of up to 6 weeks
– Symptomatic &/or displaced meniscal body tears, in knees free
from severe degenerative knee osteoarthritis
– Symptomatic meniscal root tears, with goal of
preventing/slowing progression of osteoarthritis
– Absent or nonviable meniscus (previous meniscectomy)
57
Q
Meniscus Injury
Complications
A
- arthrofibrosis
- infection
- septic arthritis
- deep vein thrombosis
- patella fracture
- neurovascular damage
- failure to heal
- hardware irritation or suture irritation
- cyst formation
- retear
- need for reoperation
- allograft rejection with meniscal transplant
58
Q
Prepatellar Bursitis etiology
A
- Cumulative microtrauma
- Acute trauma
- Infection
– Staph aureus (80-90% of cases), usually by direct inoculation
59
Q
Prepatellar Bursitis clinical presentation
A
- localized swelling of soft tissue over patella
- bursal fluctuance
- painless or only slightly painful joint range of motion (except at extreme flexion)
- septic prepatellar bursitis
– suspected with warmth, erythema, skin abrasion, or cellulitis over patella
– Fever possible
60
Q
Prepatellar Bursitis
Diagnosis
A
- Clinical
- Septic bursitis
– Confirmed with isolation of pathogen from culture of bursal aspirate
61
Q
Prepatellar Bursitis
Management
A
- RICES
- If septic prepatellar bursitis suspected
– affected bursa should be aspirated & sent for immediate culture analysis
– corticosteroid injection contraindicated if bursa infected or inflamed
– oral antibiotics targeting staphylococci & streptococci - IV administration reasonable if infection severe
– incision & drainage may be considered for severe septic bursitis - Bursectomy reserved for refractory cases
62
Q
Prepatellar Bursitis
Complications
A
- Infection of associated joint or underlying bone if patient immunocompromised or
delay in starting antibiotics - Rarely, bacteremia after prolonged septic bursitis, possible if patient
immunocompromised - complications of treatment
63
Q
Patellofemoral Syndrome etiology
A
- Exact cause unknown
– likely due to abnormal tracking of patella over the femoral condyles &/or
patellofemoral joint overload
64
Q
Most common cause of anterior knee pain
A
Patellofemoral Syndrome
65
Q
Patellofemoral Syndrome
Clinical Presentation
A
- Patient c/o anterior knee pain described as being behind, around, or underneath
patella
– usually gradual onset (could be acute, if associated with trauma)
– worse with prolonged sitting (theatre sign) or going down stairs
– may be exacerbated by running, jumping, or climbing stairs
66
Q
Patellofemoral Syndrome
Diagnosis
A
- History + Clinical exam
– suspect patellofemoral pain syndrome in patients with anterior knee pain
exacerbated by long periods of sitting or descending stairs
– Painful resisted knee extension
– Painful squatting - X-ray may be helpful to r/o other conditions
- MRI (usually not necessary)
67
Q
Patellofemoral Syndrome
Management
A
- RICES
- Activity modification
- NSAIDS
- Corticosteroid injection
- Physical rehabilitation
- Patellar taping, bracing &/or foot orthoses may be helpful
- Surgery reserved for cases refractory to conservative measures x 6-12 months
68
Q
Iliotibial Band Syndrome etiology
A
- combination of repetitive stress & biomechanical factors
– tightness of ITB
– weakness of knee extensors, flexors, & hip abductors
– low hamstring strength compared to quadriceps strength on same side
– femoral external rotation
– angle of knee flexion (ITB rubs against underlying structures at position of 20-30°)
– leg length discrepancy (injury to longer leg)
– abnormal foot & ankle mechanics (rear foot pronation, internal tibial rotation)
– excessive hip adduction
– narrow step width
69
Q
Iliotibial Band Syndrome
Clinical Presentation
A
- Patient may describe:
– Progressive tenderness over lateral femoral
epicondyle &/or Gerdy tubercle
– In less severe cases, pain may initially subside
upon cessation of activity
– Pain worsened on stairs
70
Q
Iliotibial Band Syndrome
Clinical Presentation
A
- Pattern of pain typical for runners
– Initially occurs after completion of a run with
progressively earlier occurrence during running
sessions, & eventually progressing to pain when
at rest
– Occurs while lengthening stride
– Worsens after running long distances, while
running downhill, or outside
71
Q
Iliotibial Band Syndrome
Diagnosis
A
- History of lateral knee pain associated with
repetitive weight-bearing motion; - Physical exam
– + Noble compression test
– + Ober test
– + Modified Thomas test to assess for tightness
of the ITB, iliopsoas, & rectus femoris - Consider magnetic resonance imaging to rule out
other causes if clinical exam unclear
72
Q
Iliotibial Band Syndrome
Management
A
- Activity modification
- RICES
- NSAIDS
- Corticosteroid injection (between lateral femoral condyle & ITB)
- Physical rehabilitation
- Surgical intervention if conservative measures fail
– Debridement
– ITB release
– ITB bursectomy
73
Q
Iliotibial Band Syndrome
Complications
A
- Pain
- Biomechanical compensation
- ITB rupture (with corticosteroid rupture)
