Brainscape's Knowledge GenomeTM

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


See full index

Orthopaedics > Joints > Flashcards

Joints Flashcards

1
Q

What is the risk of hip dislocation in primary and revision cases?

A

Primary: 0.5% -6%
Revision: 2%-20%

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

Risk factors for hip dislocation?

A

Patient factors: Parkinson’s, dementia, spasticity, alcoholism, previous hip surgery, osteonecrosis, obesity, hip fx’s
Surgical factors: head size, restoration of leg length and offset, impingement, surgeon experience, approach

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

Surgical tx of hip instability during THA?

A

Larger femoral heads
Optimizing implant position
Addressing sources of impingement
Increasing offset and/or leg length

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

Relative indications for constrained liners

A
  • absent abductor mechanism
  • recurrent dislocation in the presence of WELL-POSITIONED implants
  • failure of nonconstrained surgical solutions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Risks of constrained hip liners?

A

-implant loosening, limited motion, constraint mechanism failure

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

Ultra-high molecular weight polyethylene sterilization by gamma irradiation in air will cause what?

A
  • Oxidation; the amount of oxidation and decrease in wear performance is related to length of time that the gamma-irradiated polyethylene is exposed to oxygen
  • oxidation degrades wear performance of ultra-high molecular weight polyethylene!
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the most important factor that predicts progression of osteonecrotic lesion of femoral head in asymptomatic pt?

A

-Size of the lesion (particularly when over 1/3rd of the size of the femoral head) is a significant risk factor for progression

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

What total knee implant design is associated w/ the most knee flexion after TKA?

A

Posterior cruciate-stabilized implant, w/ or w/o a higher flexion manufacturing modification

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Risk for hip dislocation increases w/ revision surgery!

A

.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the principle negative effect of increasingly high crosslinking in UHMH polyethylene?

A

-The polyethylene loses fatigue strength

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

What is important to know about the transfemoral approach (extended trochanteric osteotomy) during revision hip surgery?

A

This approach reduces the torque-to-failure (fracture) of the construct to less than 50% of the intact femur. This is important to guide post-op rehab.

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

Early post-op infections following primary THA are most likely caused by which organism?

A
  • Staph aureus (most common first 4 wks post-op)
  • Staph epidermidis, Strep viridans, and Propionibacterium acnes are more commonly found in late (>4 wks post-op) infections
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Generally, TKA can fail for the following reasons

A
  • Infection
  • Instability
  • Aseptic loosening
  • Stiffness
  • Extensor mechanism dysfunction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Managing an infected TKA

A

Managing an infected TKA requires knowledge of the timing and circumstances surrounding the infected implant. Patients with acute infections (symptom duration of fewer than 3 weeks) are candidates for debridement and prosthesis retention. Chronic infections (symptoms lasting longer than 3 weeks and for more than 3 months from the time of index arthroplasty) should be treated with resection arthroplasty, parenteral antibiotics, and reimplantation surgery at a later date. Evaluation of possible acute infections should include aspiration, serology, and alpha-defensin.

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

Instability following TKA

A

common cause of early failure and revision surgery. The etiology of instability can include overresection of the posterior condyles, collateral ligament insufficiency, and late rupture of the posterior cruciate ligament. Recognizing the cause of instability is critical to eventual successful revision. Typically, isolated polyethylene exchange is not effective or reliable to address instability. In many cases, component malrotation and ligament imbalance contribute to instability. Revision surgery focuses on restoration of the joint line, proper femoral and tibial component rotation, and restoration of the femur posterior condylar.

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

Managing component loosening and osteolysis in TKA

A

Component loosening and osteolysis are the common mechanisms of TKA failure. Prior to revision, concurrent infection must be ruled out as a source of failure. At the time of revision, proper fixation and rotation of the femoral and tibial components must be ensured. If the components are well fixed and rotated, successful isolated bearing exchange and bone grafting in the setting of osteolysis is possible. Isolated component exchanges also can be successfully performed, provided the remaining components are in an acceptable position. However, when in doubt, revision of both components generally yields more consistent results.

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

Managing stiffness following TKA

A

Stiffness following TKA can affect as many as 10% of patients following surgery. Depending on the timing and extent of arthrofibrosis, treatment options include manipulation under anesthesia or revision TKA. Manipulation typically is effective early during the postsurgical course (for up to 4 months) and is most effective for loss of flexion. To address chronic stiffness and arthrofibrosis, revision TKA offers modest improvements in range of motion. Isolated polyethylene exchange has proven inconsistent in this setting, so revision of both components to ensure proper component rotation and joint line restoration offers the best chance to improve range of motion.

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

peri-op blood management in elective ortho surgery

A
  • Hypotensive epidural anaesthesia seems to be an advantageous method in minimising peri-operative blood loss
  • In addition, post-operative blood cell saving systems after total knee or hip arthroplasty have been reported to significantly minimise allogeneic blood transfusions when compared to control groups.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what radiographic finding on AP pelvis is more common in pts w/ Marfan syndrome?

A

Acetabular protrusio

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

coxa magna

A

Coxa magna is the asymmetrical, circumferential enlargement and deformation of the femoral head and neck.

21
Q

wound healing issues after TKA options for coverage of exposed deep soft tissues?

A

Local rotational flaps such as gastrocnemius flaps

22
Q

In terms of objective laxity and clinical outcomes, respectively, a double-bundle anterior cruciate ligament (ACL) reconstruction will produce which findings when compared to a single-bundle ACL reconstruction?

A

Decreased laxity and similar clinical outcomes

23
Q

how to increase flexion gap in TKA?

A
  • Increase in flexion gap can be accomplished by downsizing the femoral component and increasing posterior tibial slope. In posterior cruciate-retaining TKA procedures, recession or release of the posterior cruciate ligament can loosen the flexion gap, allowing for an increase in flexion.
  • Flexing the femoral component tightens the flexion gap, and downsizing the tibial insert thickness decreases flexion and extension gaps, while resection of the distal femur only increases the extension gap.
24
Q

failure to adequately repair the gluteus medius during a lateral approach to the hip can result in what?

A

Trendelenburg gait

25
Q

most common femoral defect during revision THA?

A

A Paprosky type IIIA femoral defect is the most commonly encountered defect during revision THA. This defect involves severe damage of the metaphysis but more than 4 cm of cortical bone available for scratch fit along the femoral isthmus. Accepted methods of reconstruction include impaction grafting using a long tapered fluted stem and extensively coated diaphyseal fitting components. A proximal fitting stem does not address the metaphyseal defect and should not be used. Poor results are associated with use of cemented femoral components with this defect type.

26
Q

work-up of a painful metal on metal hip arthroplasty?

A

Several algorithms have been proposed. Routine laboratory studies including sedimentation rate, CRP, and serum cobalt and chromium ion levels should be obtained for all patients with pain. Advanced imaging including MARS MRI should be performed to evaluate for the presence of fluid collections, pseudotumors, and abductor mechanism destruction. Infection can coexist with metal-on-metal reactions, so, when indicated (if the CRP level is elevated), a hip arthrocentesis should be obtained. However, in this setting, a manual cell count and differential should be obtained because an automated cell counter may provide falsely elevated cell counts.

27
Q

Post-perthes hip

A
  • coxa magna w/ flattening of femoral head
  • acetabular retroversion in 50% of hips and a short neck w/ a high-riding trochanter which may impinge in abduction and can be a cause of lateral hip pain
28
Q

a complication unique to computer navigation of TKA is?

A

femoral shaft fracture
-Threaded pins are frequently inserted into the femoral shaft and tibial shafts or proximal tibia to attach arrays for tracking devices. There have been case reports of fractures propagating through the pin tracks, which is a complication unique to computer navigation.

29
Q

In a pain-free metal-on-metal hip, the presence of fluid collection on ultrasound may indicate the development of a pseudotumor even in the absence of elevated metal ions or pain. Because of the potential for devastating soft-tissue destruction, revision surgery is typically recommended.

A

.

30
Q

Nerve injuries with various approaches to the hip?

A

The lateral femoral cutaneous nerve can be injured during a direct anterior approach to the hip. The superior gluteal nerve enters the gluteus medius from posterior to anterior approximately 5 cm above the greater trochanter. This nerve can be injured during the direct lateral and anterolateral approaches to the hip. Branches of the inferior gluteal nerve as well as the sciatic nerve can be injured during the posterior approach, and the obturator nerve can be damaged when performing a medial approach to the hip.

31
Q

Tx for grade III posterolateral corner injury?

A

Surgical treatment is the preferred treatment for grade III posterolateral corner injuries with poor outcomes in those treated non-surgically. Recent studies have found significant improvement in outcomes when posterolateral corner structures such as the fibular collateral ligament, popliteus, and popliteofibular ligament are reconstructed as opposed to repaired.

32
Q

which lab marker is highly sensitive and specific for determining level of degenerative knee pathology?

A

Serum stromelysin

33
Q

What is the most well-documented advantage of computer-assisted navigation for total knee arthroplasty (TKA)?

A

Decreases radiographic outliers

34
Q

synovial chondromatosis

A
  • multiple calcified masses in joint
  • benign chondroid massess on biopsy
  • benign conditions tx by open, complete synovectomy of the joint
35
Q

Chondroblastoma

A

osseous lesion and almost never has a soft-tissue extension

-biopsy specimen would show cobblestone chondroblasts w/ occasional giant cell-like osteoclasts

36
Q

When using an intramedullary device for fixation of a pertrochanteric hip fracture, risk for anterior cortical perforation is increased by which circumstance?

A

Posterior one-third trochanteric starting point

37
Q

Radiographic signs of hip stem loosening

A

Signs vary based on fixation type. Signs of loose UNcemented stems include radiolucent lines around the porous surface, stem subsidence, pedestal formation distal to the tip of the stem, or stem fracture.
Signs of a loose CEMENTED stem include radiolucent lines at the implant-cement or bone-cement interfaces, implant subsidence, cement mantle fracture, or stem fracture. These changes are best observed on serial radiographs if available

38
Q

Signs of loose uncemented femoral stems

A

Signs of loose uncemented stems include radiolucent lines around the porous surface, stem subsidence, pedestal formation distal to the tip of the stem, or stem fracture.

39
Q

Signs of loose cemented femoral stems

A

Signs of a loose cemented stem include radiolucent lines at the implant-cement or bone-cement interfaces, implant subsidence, cement mantle fracture, or stem fracture

40
Q

A CRP level exceeding 100 mg/L during the acute postsurgical period is a joint aspiration indication.

A

.

41
Q

synovial fluid diagnosis of PJI?

A

The threshold for synovial fluid analysis for an acute PJI is 10000 cells/µL and more than 90% PMN neutrophils vs 3000 cells/µL and more than 80% PMN neutrophils for a chronic infection.

42
Q

Which treatment is associated with decreased complications related to femoral nerve blocks for TKA?

A
  • Knee immobilizer
  • Femoral nerve blocks improve pain but also have a large impact on quadriceps and motor function, which places patients at higher risk for falls.
43
Q

Which artery must be mobilized in a medial gastroc rotational flap to cover a medial proximal tibia skin defect during TKA?

A
  • Medial sural artery
  • The medial sural arteries vascularize the gastrocnemius, plantaris, and soleus muscles proximally. They arise from the popliteal artery. If not adequately mobilized, a gastroc soleus flap can be devascularized.
44
Q

The optimal method with which to diagnose component malrotation in total knee arthroplasty (TKA) is…?

A
  • CT scan with metal artifact suppression
  • The epicondylar axis and tibial tubercle can be used as references on CT scans to quantitatively measure rotational alignment of the femoral and tibial components.
45
Q

This neurovascular structure limits distal extension of the direct anterior approach.

A
  • Femoral nerve
  • Distal extension of the direct anterior approach beyond the intertrochanteric line poses risk for injury to the lateral and medial division of the femoral nerve, which innervates the anterolateral parts of the quadriceps muscle group. In addition, branches of the lateral circumflex artery are routinely ligated in a standard approach.
46
Q

Valgus knee OA is predominantly associated with what?

A
  • Hypoplastic lateral femoral condyle

- Can lead to internal rotation of femoral component and cause patella maltracking if not recognized and addressed

47
Q

What is the primary cause of a CAM deformity?

A

-Repetitive activities involving an open proximal femoral physis

48
Q

When using the measured resection technique during total knee arthroplasty (TKA), the best way to avoid femoral malrotation is to reference the?

A

-AP axis

Orthopaedics (13 decks)

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