3. Adult Reconstruction (Hip & Knee) MCQs

A 45-year-old active man presents with a high-pitched squeaking noise from his hip 3 years after a cementless primary THA with a ceramic-on-ceramic bearing. The noise occurs primarily during deep flexion activities. Which of the following component positional factors most strongly correlates with this phenomenon?

A 72-year-old man presents with a painful TKA 4 years postoperatively. Both ESR and CRP are elevated. Joint aspiration yields synovial fluid with a WBC count of 4,500 cells/uL and 85% neutrophils. Which additional synovial fluid test has the highest specificity for confirming a periprosthetic joint infection?

An 82-year-old woman with a history of recurrent posterior dislocations following a primary THA presents for revision. She has severe neuromuscular weakness and poor compliance with hip precautions. Her abductor mechanism is deficient but structurally intact. What is the most appropriate acetabular reconstruction option to minimize future dislocation risk?

A 68-year-old man presents 1 year after a posterior-stabilized TKA complaining of a painful catch and audible "pop" in his knee when extending from a flexed position. The examination is otherwise normal, and radiographs are unremarkable. What is the most likely etiology of his symptoms?

A 55-year-old woman is being evaluated for a medial unicompartmental knee arthroplasty (UKA). According to classical and modern guidelines, which of the following preoperative findings is an absolute contraindication for this procedure?

In total hip arthroplasty, the use of highly cross-linked polyethylene (HXLPE) has significantly reduced wear rates compared to conventional polyethylene. Which of the following manufacturing processes specifically decreases the fatigue strength and fracture toughness of HXLPE?

A 58-year-old woman complains of persistent groin pain 6 years after receiving a metal-on-metal total hip arthroplasty. Aspiration of the hip yields sterile, blood-tinged fluid. MRI demonstrates a large, solid and cystic periarticular mass. Histologic examination of the periarticular tissue would most likely demonstrate which of the following?

During a primary TKA in a patient with a varus deformity, the surgeon assesses the gaps using spacer blocks after making the initial bone cuts. The knee is tight medially in both extension and flexion. What is the most appropriate initial soft tissue release to balance the knee?

An 81-year-old man falls and sustains a periprosthetic femur fracture around his cemented THA.

Radiographs reveal a fracture occurring around a loose femoral stem, but with adequate surrounding proximal bone stock. What is the most appropriate surgical treatment?

A 66-year-old man undergoes explantation of an infected TKA and placement of an articulating antibiotic-loaded cement spacer. Six weeks later, his wound is well-healed, and serum ESR and CRP have normalized. Before proceeding with the second-stage reimplantation, what is the most appropriate next step to confirm eradication of the infection?

During trialing in a primary THA via a posterior approach, the surgeon notes the leg lengths are perfectly equal to the contralateral side, but the hip easily dislocates in adduction and internal rotation. To increase stability via soft tissue tensioning without altering the leg length, which of the following component changes should be made?

A 70-year-old woman presents with progressive knee pain 12 years after a primary TKA.

Radiographs demonstrate extensive osteolysis behind the tibial tray. Which of the following factors is most strongly associated with accelerated polyethylene wear and subsequent osteolysis in TKA?

During a primary total knee arthroplasty (TKA), the surgeon decides to use a posterior-stabilized (PS) implant. Which of the following best describes the primary mechanical function of the cam-and-post mechanism in this design?

A 65-year-old man presents with an audible and palpable squeaking sound from his right hip 2 years after a primary total hip arthroplasty (THA). Radiographs show well-fixed components. What is the most likely bearing surface combination he received?

A 68-year-old woman presents with a painful total knee arthroplasty 4 years post-surgery. Her serum ESR and CRP are elevated. Aspiration yields synovial fluid. According to the Musculoskeletal Infection Society (MSIS) criteria, what minimum synovial fluid white blood cell (WBC) count strongly indicates a chronic periprosthetic joint infection?

A 70-year-old man undergoes revision THA for recurrent posterior dislocations. During the procedure, the surgeon notes that the existing acetabular component is in neutral version. To minimize future posterior instability, the surgeon should reposition the cup to achieve which target orientation?

A 62-year-old woman complains of a painful catch and an audible pop when actively extending her knee from a flexed position, one year after a primary TKA.

What implant design or technical factor most increases the risk of this specific complication?

A 55-year-old woman presents with persistent groin pain and a palpable mass 4 years after a metal-on-metal THA. Imaging reveals a solid and cystic mass adjacent to the joint. Which histological finding is most characteristic of this condition?

During a primary TKA using a measured resection technique, the extension gap is symmetric and perfectly balanced, but the flexion gap is unacceptably tight. What is the most appropriate surgical step to correct this mismatch?

An 82-year-old woman falls and sustains a periprosthetic femur fracture around her cementless THA stem.

Radiographs demonstrate a fracture at the tip of the stem. The stem is loose, but there is adequate proximal bone stock. According to the Vancouver classification, what is the standard treatment?