TOPIC DETAILS

No contributor information available.

Dislocation 

Predisposing factors for dislocation Divide these into:

Patient-specific risk factors (female sex, AVN, obesity, increased age, co-morbidities, femoral neck facture)

Variables under the surgeon’s control (surgical approach, component position and orientation, femoral head size, restoration of offset, preservation of soft tissue integrity, leg length and prosthetic impingement)

Surgeon experience (risk of dislocation inversely related to the case volume of the operating surgeon)

Management options

These include

Closed reduction with or without bracing
Greater trochanter advancement.
Dated option as modular implants largely superceeded this choide 
Soft-tissue augmentation
Only used if no component mal-alignment,implant well fixed and a young patient.Even with these strict criteria this is often unsuccessful so more of a historic option than something to seriously consider.There are better more successful options available.
THA component revision
Exchange of modular parts
Tripolar unconstrained acetabular component (dual motion)
Elevated rim liners
Use of a large femoral head
Use of a constrained acetabular liner

The choice depends very much on the aetiology of the problem. Revision arthroplasty for recurrent dislocation is much more likely to be successful when a cause has been identified

Previous
Next

QUESTION 1 OF 25

A 69 year old woman is seen as an emergency add on to the orthopaedic clinic.She underwent cemented total hip replacement two weeks previously. Her wound has been persistently draining since she was discharged from hospital.She is well within herself, apyrexia with minimal hip pain.
The next most appropriate course of action is to

QUESTION ID: 1104

1. A. Aspiration hip
2. B. DAIR hip
3. C. Discontinue anticoagulation treatment
4. D. Start oral antibiotics
5. E. Swab the wound

QUESTION 2 OF 25

85.A 24 year old male presents to the orthopaedic clinic with a 2 year history of progressively worsening left hip pain.Pain limits his walking distance to around a ¼  of a mile and causes sleep disturbance at night.He is struggling to climb ladders at work as a scaffolder and can no longer play football.Anteroposterior (AP)radiograph hip is shown below(Figure 1 ).
The most appropriate course of action would be to:

oa left hip.png

Figure 1.Anteroposterior(AP)radiograph hip

QUESTION ID: 1106

1. A. Advise he is too young to undergo THA and he should continue with conservative management of his hip arthritis
2. B. List for an uncemented ceramic on HCLPE THA
3. C. List for Hip fusion
4. D. List for steroid local anaesthetic injection hip
5. E. Refer on to hip surgeon who performs MoM resurfacing

QUESTION 3 OF 25

A patient is seen in the outpatient clinic with severe bilateral end stage arthritis.She asks that both hips be operated on at the same time as it would “get them both out of the way in one sitting”
Compared to a two staged bilateral THA procedure a one stage bilateral THA procedure has:

QUESTION ID: 1107

1. A. A lower DVT risk
2. B. Increased cardiovascular complications
3. C. Increased dislocation rate
4. D. Increased risk of death
5. E. Longer operation time

QUESTION 4 OF 25

You see and list a 76 year old female for a left total hip replacement. She has moderate Parkinson’s disease
The most appropriate option to reduce her dislocation risk would be:

QUESTION ID: 1109

1. A. A change from a normal posterior approach to the hip to an anterolateral Hardinge approach.
2. B. Captive cup
3. C. Dual mobility
4. D. Lipped liner
5. E. Use of a large femoral head (36mm if possible)

QUESTION 5 OF 25

92.A 43-year-old woman presents to clinic with groin pain. She had undergone a right MoM hip resurfacing three years previously
Concerning her MRI scans below(Figure 1):

hip picture.png

Figure 1 .MRI pelvis axial T2.

QUESTION ID: 1168

1. A. Appearance would be consistent with her painful symptoms and lack of function
2. B. Diagnosis can be confirmed with macroscopic inspection
3. C. Is specific for an adverse reaction to metal debris
4. D. Pathogenesis involves a delayed hypersensitive (type IV) response to Co-Cr particles
5. E. There is a spectrum of necrotic and inflammatory changes in response to deposition of cobalt chromium wear particles

QUESTION 6 OF 25

A 76-year-old male attends the arthroplasty follow up clinic. He had a cemented total hip arthroplasty performed 10 years previously using a lateral Hardinge type approach. He complains of anterior thigh and knee pain with walking. Clinical examination reveals an antalgic gait with abductor lurch.
The most likely diagnosis would be

QUESTION ID: 1169

1. A. Infection
2. B. Loose femoral component
3. C. Vastus lateralis muscle herniation
4. D. Abductor muscle atrophy with partial gluteal detachment
5. E. Thoracolumbar discogenic pain

QUESTION 7 OF 25

A 52-year-old male attends clinic with a fused hip. Fusion was performed 30 years previously following an RTA with an acetabular fracture and secondary development of osteonecrosis. He complains of severe low back pain and ipsilateral knee pain. Radiographs show a cobra head plate in place with some concern about his abductor muscle mass

The most appropriate assessment would be:

QUESTION ID: 1171

1. A. CT scan to access abductor status
2. B. Electromyography
3. C. Inspection and palpation abductor muscle mass
4. D. MRI scan to access abductor status
5. E. U/S scan abductor muscle

QUESTION 8 OF 25

90.A 78-year-old female is seen in the outpatient clinic with severe bilateral end stage arthritis. She asks that both hips be operated on at the same time as it would “get them both out of the way in one sitting and save time”
Compared to a staged bilateral THA procedure a simultaneous bilateral total hip arthroplasty (SBTHA)has

QUESTION ID: 1173

1. Increased cardiovascular complications
2. Increased dislocation rate
3. Increased DVT risk
4. Increased risk of death
5. Increased transfusion requirements

QUESTION 9 OF 25

You see and list a 76-year-old female for a left total hip arthroplasty. She has moderate Parkinson’s disease

The most appropriate option to reduce her dislocation risk would be

QUESTION ID: 1175

1. A. A change from a normal posterior approach to the hip to an anterolateral Hardinge approach.

QUESTION 10 OF 25

You are performing a hybrid hip replacement in a 62-year-old patient with mild cognitive impairment. There is a pre-operative concern about instability. The bone quality appears very poor at surgery. The definitive cup is a press fit design but is loose when impacted.
The most appropriate action is to

QUESTION ID: 1176

1. A. Insert an uncemented TM revision cup
2. B. Supplementary screw fixation
3. C. Convert to using a cement cup
4. D. Change to a line to line cup with screw fixation
5. E. Insert the next sized larger cup into the acetabulum

QUESTION 11 OF 25

87.A patient with a large BMI (≥ 40) has been referred to your clinic for a second opinion regarding the need for THA.The first surgeon who she met in clinic turned her down for THA mentioning that risks of complications were too significant with a large BMI
With an increased BMI over 40 there is:

QUESTION ID: 1177

1. Higher risk of revision for aseptic loosening
2. Higher risk of revision for mechanical failure of the implant
3. Increased risk of mortality
4. Lower patient recorded outcome measure(PROMs)values
5. Reduced improvement in pain scores compared to non obese patients

QUESTION 12 OF 25

In theatre you are the main surgeon performing a cemented total hip arthroplasty. As the scrub nurse is mixing the cement, they mention that they had recently been on a “nursing cement training day” organised by one of the implant companies. She was a little unsure about the difference between third and fourth generation cementing techniques
You mention:

QUESTION ID: 1179

1. Fourth generation cementing involves late insertion of an implant into viscous cement
2. Fourth generation cementing involves using serial high pressure pulsed lavage
3. Fourth generation involves using distal and proximal centralizers to ensure an even cement mantle
4. Fourth generation techniques involve improved stem designs
5. Third and fourth generation cementing techniques are essentially the same procedure

QUESTION 13 OF 25

83.A 72-year-old man returns to arthroplasty follow up clinic 1 year following cemented THA.His AP radiograph is shown below(Figure 1).
Concerning the x-ray appearance:

q19.jpg

Figure 1.Anteroposterior(AP) radiograph pelvis 

QUESTION ID: 1180

1. Early removal is advisable in order to reduce the risk of dislocation
2. It is a rare occurrence (<5%) occurring after THA
3. Pathophysiology is an abnormal differentiation of pluripotent mesenchymal stem cells
4. Risk factor includes posterior approach
5. Very likely to result in lower Harris hip scores

QUESTION 14 OF 25

 A 76-year-old female dislocates her THA 1 day post-operatively in bed the next morning following surgery. The THA was performed by a trainee orthopaedic surgeon although they were being closely supervised by their consultant  
The most likely reason for the dislocation occurring would be:

 

QUESTION ID: 1182

1. Component mal-alignment
2. Failure to remove osteophytes
3. Large retained piece of cement in the hip joint
4. Non compliance with post operative hip precautions
5. Using a posterior approach to the hip and failing to adequately repair the soft tissues

QUESTION 15 OF 25

82.A 81-year-old man is admitted from the ED with a dislocated left THA.He underwent the surgery 3 weeks previously.
The strongest independent patient predictor of early THA dislocation (within 40 days) is:

QUESTION ID: 1183

1. Dementia
2. Depression
3. Lung disease
4. Parkinson’s disease
5. Spinal fusion

QUESTION 16 OF 25

A 43-year-old male presents to the orthopaedic clinic with an 8-week history of severe left hip pain His radiographs are shown below (Figure 1)
The most appropriate treatment would be.

Figure 4.8Q. jpg.jpg

Figure 1.Anteroposterior (AP) radiograph hip

QUESTION ID: 1196

1. Bisphosphonates
2. Cemented total hip replacement
3. Core decompression
4. Hip resurfacing
5. Vascularised fibular graft

QUESTION 17 OF 25

A 78-year-old female who underwent right THA via a posterior approach is seen the next morning with a dense painful foot drop.
The most appropriate initial management is:

QUESTION ID: 1197

1. MRI scan
2. Nerve conduction studies
3. Physiotherapy and foot drop splint
4. Radiographs hip
5. Re-exploration of the hip

QUESTION 18 OF 25

 A 78-year-old female is seen in the outpatient clinic with severe bilateral end stage arthritis. She asks that both hips be operated on at the same time as it would “get them both out of the way in one sitting and save time”
Compared to a two staged bilateral THA procedure a one stage bilateral THA procedure has

QUESTION ID: 1240

1. A lower DVT risk
2. Increased cardiovascular complications
3. Increased dislocation rate
4. Increased risk of death
5. Longer operation time

QUESTION 19 OF 25

You are performing a hybrid hip replacement in a 61-year-old patient with mild cognitive impairment. There is a pre-operative concern about instability. The bone quality appears very poor at surgery. The definitive cup is a press fit design but is loose when impacted.
The most appropriate action is to

QUESTION ID: 1242

1. Change to a hydroxyapatite cup with screw fixation
2. Convert to using a cement cup
3. Insert an uncemented TM revision cup
4. Insert the next sized larger cup into the acetabulum
5. Supplementary screw fixation

QUESTION 20 OF 25

28..An 80 year old lady is being worked up for a revision hip arthroplasty for aseptic acetabular component loosening.You are planning to revise the acetabular component to an uncemented porous coated shell.
Which of the following statements is correct regarding the safe zones of acetabulum?

Too small copy.png


QUESTION ID: 1276

1. Anterior-inferior quadrant has good bone stock compared to Posterior-superior quadrant
2. Anterior-superior quadrant is generally considered a safe zone for placement of acetabular screws
3. Risk of external iliac vessel injury is high with posterior-inferior quadrant
4. Risk of injury to inferior gluteal and pudendal vessels is high with posterior-inferior quadrant
5. Risk to superior gluteal vessels is high with anterior superior quadrant

QUESTION 21 OF 25

33.You are performing a hybrid THA for a 76-year-old female patient, when inserting the uncemented cup you notice a crack in the bone extending superiorly from the interface between the cup and bone. The fracture line extends 3cm superiorly. The cup is stable.
What is the most appropriate thing to do?

QUESTION ID: 3229

1. Continue with THA as planned.
2. Fix the fracture with a compression plate.
3. Insert screws into the cup.
4. Remove uncemented cup and insert cemented cup.
5. Remove uncemented cup and insert triflange cage spanning fracture.

QUESTION 22 OF 25

34.Which of the following patients would it be most appropriate to treat with THA for fractured intra-capsular neck of femur?

QUESTION ID: 3230

1. A 55-year-old lady with multiple sclerosis who mobilises with a frame.
2. A 65-year-old male who mobilises with a single walking stick.
3. A 65-year-old smoker with lung cancer with a possible pathological fracture
4. A 65-year-old with Parkinson’s disease
5. A 74-year-old lady with past medical history of rheumatoid arthritis

QUESTION 23 OF 25

40.A 35-year-old male patient wakes with severe groin pain the day after hip resurfacing surgery.
Which of the following complications is most likely?

QUESTION ID: 3236

1. Femoral neck fracture.
2. Femoral nerve injury.
3. Haematoma.
4. Iliopsoas impingement.
5. Sciatic nerve injury.

QUESTION 24 OF 25

46.You start a job as a Hip Consultant. Your clinical lead advises that you use an implant with a ODEP 10 A * rating.
What does the * indicate.

QUESTION ID: 3242

1. Acceptable evidence
2. Being evaluated through the Beyond Compliance initiative
3. Benchmark revision rate less than 1 in 10 at 10 years
4. Benchmark revision rate less than 1 in 20 at 10 years
5. Strong evidence

QUESTION 25 OF 25

50.Whilst washing the femoral canal during a first stage revision for infection you are offered a choice of irrigation solutions.
Which would be least suitable?

QUESTION ID: 3246

1. Acetic acid
2. Chlorhexidine
3. Hydrogen peroxide
4. Polyhexanide-betaine
5. Povidone-iodine