4.0 of 13 Ratings
A 45-year-old female is referred to you for evaluation of her right hip. Five years ago, she was involved in a motor vehicle collision and sustained a femoral head fracture that was treated with a hip surface replacement arthroplasty. Her post-operative course was unremarkable and she didn't have any issues until 4 months ago when she noticed subtle hip and groin pain. She is otherwise healthy and wants to begin training for a marathon but is concerned about her hip due to television ads about metal-on-metal devices. Her radiographs show a well-placed implant and are otherwise unremarkable. What test would best evaluate for the most concerning complication from this implant?
CT including the pelvis, hip, and femur
Whole body triple-phase bone scan
MRI with metal artifact reduction sequence
Serum cobalt and chromium levels
Serum cobalt, chromium, molybdenum, and nickel levels
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Figure A is a histologic specimen of a joint pseudocapsule surrounding a cobalt-chromium second-generation metal-on-metal (MOM) hip replacement prostheses. The dark areas represent:
Infiltrates of T-lymphocytes
Infiltrates of B-lymphocytes
Infiltrates of T- and B-lymphocytes
A 38-year-old female patient presents to your office three years after a hip resurfacing. She complains of worsening left hip discomfort for the last 6 months. Her ESR is 12 (normal 0-20) and CRP is 1.2 (0-5). A radiograph and axial and coronal MRI scans are shown in Figures A, B, and C. What is the most likely diagnosis?
Type I Hypersensitivity reaction
Femoral neck fracture
Figure A shows a radiograph of a 62-year-old female that underwent a left total hip arthroplasty 5 years ago. She presents to your office with insidious onset of left groin and buttock pain. She denies trauma, fever or chills. On physical examination, her left hip has mild pain with range of motion. She has a normal gait cycle, normal power across the hip and her vitals signs are stable. A left hip aspirate was performed and results are shown in Figure B. What is the most likely cause of her hip pain?
Periprosthetic bacterial hip infection
Periprosthetic hip fracture
Large-particle wear debris disease
Pseudotumor hypersensitivity response
Abductor tendon tear
A metal-on-metal bearing used for total hip arthroplasty shows which of the following properties?
Baseline serum ion levels increase with increasing activity levels.
The risk of cancer is substantially increased.
Linear ion production increases over time.
Ions produced are excreted primarily through the kidney.
Nickel is the most prevalent ion released into circulation.