Joint Replacement — Advanced (THR/TKR Complications, Revision, Bearings, Periprosthetic Fractures) MCQs

Orthopedics · 59 free questions with answers & explanations.

1. A 68-year-old woman with a cemented total hip replacement performed 12 years ago presents with groin pain and periprosthetic osteolysis on X-ray without loosening of the acetabular component. The most likely mechanism of osteolysis in this scenario is:
2. During revision total hip arthroplasty, the femoral component is found to be well-fixed with extensive bone loss around the proximal femur. According to the Paprosky classification, a Type IIIB femoral defect is characterized by:
3. A Vancouver Type B2 periprosthetic femoral fracture after total hip arthroplasty is best managed by:
4. Ceramic-on-ceramic bearing surfaces in total hip arthroplasty offer which MOST important advantage over conventional metal-on-polyethylene?
5. A patient with a total knee replacement (TKR) presents 3 weeks post-operatively with fever, wound breakdown, erythema, and purulent discharge. The most appropriate management is:
6. A 72-year-old woman with a cemented total hip replacement performed 10 years ago presents with progressive groin pain and radiological loosening of the acetabular component. The femoral component remains well-fixed. Revision arthroplasty is planned. Which intraoperative finding would MOST reliably indicate that the femoral component should also be revised?
7. A 65-year-old man with a cementless total knee replacement develops acute knee pain and swelling 8 years postoperatively after a fall. Radiograph shows a periprosthetic distal femoral fracture with the implant appearing well-fixed. This fracture is best classified using which system, and what is the primary determinant of treatment?
8. In modern total hip arthroplasty, which bearing couple has the LOWEST wear rate and is preferred in young active patients, but carries the unique risk of 'squeaking'?
9. A 68-year-old man presents 3 weeks after cemented THR with acute severe hip pain, fever (38.9°C), raised CRP (210 mg/L), and ESR (95 mm/h). Hip aspiration yields turbid fluid with 48,000 WBC/mm³ (90% PMNs). Culture grows methicillin-sensitive Staphylococcus aureus. The MOST appropriate management is:
10. During total knee arthroplasty, a surgeon measures the tibial component in neutral mechanical alignment. Post-op the patient develops persistent mediolateral instability. On review, the tibial tray appears to be excessively internally rotated relative to the tibial tubercle. The reference landmark used to set tibial component rotation in TKR is:
11. A 68-year-old woman presents 8 years after right total hip replacement with groin pain and a lytic lesion around the acetabular cup on radiograph. Serum cobalt level is markedly elevated. Aspiration yields a gray-brown fluid. Which bearing couple is most likely responsible?
12. During revision total knee replacement, an intraoperative femoral fracture occurs at the level of the femoral stem tip. The distal fragment is well fixed to bone. Which Vancouver classification equivalent (using the Lewis & Rorabeck system for periprosthetic distal femur fractures) would this represent, and what is the preferred treatment?
13. A patient with a well-functioning total hip replacement presents 12 years later with progressive thigh pain and expanding cortical lysis on serial radiographs. An aggressive polyethylene wear pattern with dark-staining bone is found. The mechanism of osteolysis is best explained by:
14. In two-stage revision arthroplasty for periprosthetic joint infection, the antibiotic-loaded cement spacer performs which of the following additional mechanical roles beyond local antimicrobial delivery?
15. A femoral stem chosen for primary cementless total hip replacement achieves 'press-fit' fixation primarily through which mechanism in the early post-operative period?
16. A 72-year-old woman presents 8 years after a cemented total hip replacement with progressive groin pain and a serum metal ion level of cobalt 9 µg/L. CT of the hip shows a large pseudotumor with soft tissue destruction around the acetabular component. The bearing surface most likely responsible for this pattern of failure is:
17. During total knee replacement, the patella is resected to a thickness of 10 mm from an original thickness of 24 mm. The remaining patellar bone thickness after resection is 14 mm. Which complication is most likely to occur from this error?
18. A 68-year-old man with a cemented total hip replacement presents with a Vancouver B2 periprosthetic femoral fracture. The stem is noted to be well-fixed radiographically. The most appropriate management is:
19. Aseptic loosening of a cemented total hip replacement is characterised by radiolucent lines at the cement-bone interface. The zone of the acetabular component most relevant to early loosening according to the DeLee and Charnley classification is:
20. In the workup of a painful total knee replacement at 5 years, aspiration yields fluid with a white cell count of 6,500 cells/µL with 80% polymorphonuclear cells. The erythrocyte sedimentation rate is 42 mm/h and CRP is 18 mg/L. According to the MSIS (Musculoskeletal Infection Society) criteria, this represents:
21. Ceramic-on-ceramic (CoC) bearing surfaces in total hip replacement have the advantage of the lowest wear rates but carry a unique audible complication. The mechanism of this complication is:
22. A 72-year-old woman presents 8 years after total hip replacement with progressive groin pain and a rising serum cobalt level of 12 µg/L. MARS-MRI shows a large pseudotumor around the acetabular component. The most likely diagnosis and the primary implant characteristic responsible are:
23. During revision total knee arthroplasty, the surgeon notes significant bone loss of the medial tibial plateau classified as Anderson Orthopaedic Research Institute (AORI) type IIB. The most appropriate reconstructive strategy for this contained peripheral defect of >10 mm depth is:
24. A periprosthetic femur fracture occurring at the tip of a cemented femoral stem with a well-fixed stem is classified as Vancouver type B1. The recommended management is:
25. In total knee arthroplasty, posterior tibial slope is an important parameter. An excessively increased posterior tibial slope (>10°) in a posterior-stabilized TKR is most likely to result in:
26. Two-stage revision arthroplasty for periprosthetic joint infection (PJI) requires placement of an antibiotic-loaded cement spacer. The minimum interval between the first and second stage recommended by current guidelines (Musculoskeletal Infection Society criteria) before reimplantation is based on:
27. A 68-year-old woman, 8 years post left total hip arthroplasty with a 28 mm metal-on-polyethylene bearing, presents with progressive groin pain and a markedly elevated serum cobalt (42 µg/L) and chromium (38 µg/L). MRI MARS (Metal Artifact Reduction Sequence) shows a large pseudotumor with soft tissue necrosis. The most likely diagnosis and primary mechanism of failure is:
28. During revision total knee arthroplasty (TKA), the tibial stem cannot be extracted despite standard technique. The Vancouver classification is used for periprosthetic fractures around a TKA component. A fracture at the tip of a well-fixed tibial stem (stress riser) with minimal displacement in a 74-year-old is classified as:
29. A 72-year-old man with a cemented total hip replacement 12 years ago presents with sudden onset hip pain after a minor fall. X-ray shows a fracture around the femoral stem. The stem appears well-fixed with intact cement mantle, fracture is at the proximal femur around the stem (zone B1). The best management is:
30. In total hip arthroplasty, which bearing combination has the lowest in-vivo wear rate, is associated with 'squeaking' as an adverse event, and is contraindicated in patients with renal failure?
31. A 66-year-old woman develops fever, raised CRP (148 mg/L), and ESR (88 mm/hr) 4 weeks after total knee replacement. Aspiration of the knee yields 28,000 WBC/µL with 92% neutrophils and positive alpha-defensin. The organism grown is coagulase-negative Staphylococcus sensitive to rifampicin and vancomycin. She is fit for surgery. The optimal surgical management is:
32. A 72-year-old woman undergoes revision total hip replacement for aseptic loosening 12 years after the index surgery. Intraoperative cultures are sent and show no growth. Which serum marker, when persistently elevated preoperatively, most reliably distinguishes periprosthetic joint infection (PJI) from aseptic loosening before revision surgery?
33. During total knee replacement for severe varus osteoarthritis, the surgeon notes the posterior cruciate ligament (PCL) is deficient. Which implant design choice is mandated by this finding?
34. A 68-year-old man sustains a periprosthetic femoral fracture around a well-fixed uncemented total hip stem 3 years post-implantation. X-ray shows a spiral fracture at the level of the stem tip with distal cortex intact. This is classified as Vancouver type:
35. A 58-year-old active male is counselled regarding bearing surface options for his planned total hip replacement. He is concerned about implant longevity given his age and activity level. Which bearing couple has the lowest volumetric wear rate in laboratory studies?
36. A patient undergoes two-stage revision for chronic PJI after total knee replacement. Which antibiotic-loaded spacer type is preferred to maintain joint space AND allow knee motion during the interval period?
37. Adverse reaction to metal debris (ARMD) following metal-on-metal hip arthroplasty is characterised by a specific histological pattern. Which term describes the predominant histopathology seen in the periprosthetic tissue?
38. A 72-year-old woman presents 8 years after total hip replacement with groin pain and a serum metal ion level showing cobalt 8 µg/L and chromium 9 µg/L. MRI reveals a large pseudotumor adjacent to the acetabular component. The most likely bearing surface combination responsible for this presentation is:
39. During revision total knee arthroplasty, the orthopedic surgeon finds significant bone loss of the proximal tibia. According to the Anderson Orthopaedic Research Institute (AORI) classification, bone loss that is contained within the metaphysis without cortical compromise is classified as:
40. A Vancouver Type B2 periprosthetic femoral fracture following total hip arthroplasty is best defined as:
41. Squeaking in ceramic-on-ceramic total hip arthroplasty is primarily attributed to:
42. A 68-year-old man develops sudden onset severe knee pain and hemarthrosis 2 days after uncomplicated total knee replacement. The most likely diagnosis is:
43. A 68-year-old woman presents 14 years after total hip replacement with progressive groin pain and a rising serum cobalt level of 38 µg/L. Pelvic X-ray shows eccentric femoral head position within the acetabular cup. MRI reveals a large pseudotumour around the hip. What is the most likely diagnosis and primary causative mechanism?
44. A 72-year-old man with a cemented total knee replacement 8 years ago develops a Vancouver type B2 periprosthetic femoral fracture. The implant is found to be loose on imaging. What is the most appropriate management?
45. In total knee replacement, which bearing surface combination offers the lowest volumetric wear rate but carries the highest risk of catastrophic fracture?
46. During revision total hip arthroplasty, the Paprosky type IIIB acetabular defect is encountered. This classification primarily guides which aspect of the reconstruction?
47. A patient develops acute severe pain and inability to weight-bear 3 weeks after uncomplicated total hip replacement. Examination reveals the limb in flexion, adduction and internal rotation. What is the most likely diagnosis?
48. A 72-year-old woman presents 8 years after a cementless total hip replacement with groin pain, elevated ESR, and a serum cobalt level of 12 µg/L (normal <1 µg/L). MRI shows a large pseudotumour around the hip. Which bearing combination is most likely responsible?
49. A Vancouver type B2 periprosthetic femoral fracture after total hip replacement is best managed by:
50. During revision total knee replacement, significant bone loss is encountered on the tibial side. According to the Anderson Orthopaedic Research Institute (AORI) classification, Type III tibial bone loss is characterised by:
51. A 68-year-old man presents 2 years after total knee replacement with acute onset of severe pain, swelling, warmth, and sinus formation. Aspiration yields turbid fluid; synovial WBC is 78,000 cells/µL with 90% neutrophils. Culture grows Staphylococcus aureus. The most appropriate two-stage revision strategy involves:
52. The commonest cause of early failure (within 2 years) of cemented total knee replacement is:
53. Dislocation after total hip arthroplasty is LEAST likely with which approach?
54. A 72-year-old woman presents 8 years after total hip replacement with progressive groin pain. ESR is 28 mm/hr, CRP 6 mg/L. Hip aspiration shows 1,800 WBC/μL with 65% neutrophils. Plain radiograph shows lucency at the cement-bone interface around the acetabular cup. The most likely diagnosis is:
55. During revision total hip arthroplasty, the surgeon encounters a Vancouver type B2 periprosthetic femoral fracture. The stem is loose and there is good bone stock. The most appropriate management is:
56. A 68-year-old male undergoes total knee replacement. Six weeks postoperatively he develops sudden severe knee pain, fever 38.8°C, and a swollen, warm joint. Joint aspiration reveals 78,000 WBC/μL with 92% PMNs, gram stain negative. Which organism is most likely to grow on culture?
57. In metal-on-metal (MoM) total hip bearings, the characteristic adverse tissue reaction causing pseudotumor formation is known as:
58. A 75-year-old woman with a well-functioning cemented total knee replacement 12 years ago presents with anterior knee pain only on descending stairs. Radiograph shows anterior femoral notching and stress fracture of the anterior femoral cortex. This complication is related to:
59. Highly cross-linked polyethylene (HXLPE) used in modern total hip bearings reduces wear by: