3. Adult Reconstruction (Hip & Knee) MCQs

A 55-year-old man undergoes cementless total hip arthroplasty with a ceramic-on-ceramic bearing. At his 2-year follow-up, he complains of an audible squeaking sound during certain activities, though he has no pain. Radiographs (

) show well-fixed components. What is the most significant risk factor associated with this phenomenon?

A 68-year-old woman presents with persistent hip pain 3 years after a primary THA. Her ESR is 45 mm/hr and CRP is 25 mg/L. Aspiration yields a synovial WBC count of 3,500 cells/uL with 75% PMNs. Based on the 2018 International Consensus Meeting (ICM) criteria, what is the next best step to establish the diagnosis?

A 32-year-old man on chronic corticosteroids presents with bilateral hip pain. MRI (

) reveals pre-collapse avascular necrosis of the femoral head (Ficat stage II). Core decompression is planned. What is the primary mechanism by which core decompression provides pain relief and attempts to halt disease progression?

A 72-year-old woman presents for revision THA due to aseptic loosening. Intraoperatively, complete separation of the superior and inferior hemipelvis through the acetabulum is noted, along with significant host bone compromise. What is the most appropriate reconstructive technique for this pelvic discontinuity?

A 65-year-old man experiences recurrent posterior dislocations after a primary THA. Radiographs (

) show the acetabular component in 30 degrees of inclination and 5 degrees of retroversion. The femoral stem is neutrally versioned. Which surgical intervention is most likely to resolve the instability?

A 72-year-old woman with a history of recurrent instability following a revision THA is treated with a dual-mobility construct. Two years later, she presents with an acute inability to bear weight after a minor fall. Radiographs show eccentric position of the femoral head within the larger polyethylene liner.

What is the most likely diagnosis?

A 45-year-old active male underwent a cementless THA with a ceramic-on-ceramic bearing. Three years postoperatively, he complains of a new, audible squeaking sound from his hip during deep flexion. Radiographs demonstrate well-fixed components with the acetabular cup placed at 60 degrees of inclination and 30 degrees of anteversion.

What is the most likely cause of the squeaking?

A 55-year-old man presents with groin pain and a palpable anterior hip mass 7 years after a metal-on-metal resurfacing arthroplasty. Cobalt and chromium levels are significantly elevated. MRI reveals a thick-walled cystic collection communicating with the joint.

Histological examination of the periprosthetic tissue is most likely to show which of the following?

A 65-year-old man presents with a painful THA 2 years postoperatively. His ESR is 45 mm/hr and CRP is 2.5 mg/dL. Hip aspiration yields 4,500 WBC/mcL with 85% neutrophils. An alpha-defensin test is positive.

According to the 2018 International Consensus Meeting (ICM) criteria, what is the diagnosis?

A 55-year-old active man presents with an audible squeaking sound originating from his hip that occurs when bending or walking.

He underwent a primary total hip arthroplasty (THA) 4 years ago utilizing a ceramic-on-ceramic bearing. Which of the following factors is most strongly associated with the development of this complication?

A 71-year-old woman presents to the emergency department with severe hip pain and inability to bear weight after bending over to pick up an object from the floor.

She underwent a primary THA via a posterior approach 6 weeks ago. Which specific combination of hip movements most commonly precipitates this specific complication?

A 62-year-old man presents with progressive groin pain and swelling 6 years after a metal-on-polyethylene THA with a modular titanium stem and cobalt-chromium head.

Laboratory studies show an elevated serum cobalt level but a normal chromium level. Aspiration is negative for infection. What is the most likely diagnosis?

Following a primary THA performed via a direct lateral (Hardinge) approach, a patient presents with a persistent Trendelenburg gait at 6 months postoperatively.

Which nerve and corresponding muscle group are most at risk of injury with excessive superior splitting of the muscle in this approach?

A 38-year-old woman with a history of corticosteroid use for systemic lupus erythematosus presents with a 4-month history of groin pain.

Radiographs and MRI confirm Ficat Stage II osteonecrosis of the right femoral head with no crescent sign and no subchondral collapse. What is the most appropriate initial joint-preserving surgical intervention?

A polished, double-tapered, collarless cemented femoral stem is chosen for an 80-year-old patient undergoing THA.

On which biomechanical principle does this specific stem design rely to achieve and maintain stability?

An 82-year-old woman sustains a fall and incurs a periprosthetic femur fracture around a cemented femoral stem.

Radiographs demonstrate a fracture at the tip of the stem. The cement mantle is fractured, and the stem is clearly loose. The patient has adequate distal bone stock. According to the Vancouver classification, what is the recommended treatment?

Highly cross-linked polyethylene (HXLPE) has significantly reduced the incidence of wear-induced osteolysis in THA.

During the manufacturing process, irradiation is followed by a heating process (remelting or annealing). What is the primary biomechanical purpose of the remelting process?

A 55-year-old patient undergoes revision THA for a failed metal-on-metal implant presenting with a large pseudotumor.

Histopathological examination of the periprosthetic tissue demonstrates an aseptic lymphocytic vasculitis-associated lesion (ALVAL). What is the classic histological hallmark of this reaction?

A patient is evaluated for a painful total hip arthroplasty 2 years postoperatively.

According to the Musculoskeletal Infection Society (MSIS) and International Consensus Meeting (ICM) criteria, which of the following is considered a definitive "major" criterion for the diagnosis of periprosthetic joint infection (PJI)?

Proper orientation of the acetabular component is critical to minimize the risk of dislocation after THA.

According to the historically established "Lewinnek safe zone", what are the optimal target angles for acetabular inclination (abduction) and anteversion?