This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Avascular Necrosis & Osteochondroses, Subject name: Orthopaedics
[{'content': 'Which of the following is a "Fenestrated hip prosthesis"? \nSelect and explain. \nA. Bipolar prosthesis, B. Austin Moore prosthesi, C. Thompson prosthesis, D. All', 'role': 'user'}, {'content': 'Answer: B \nExplanation: ANSWER: (B) Austin Moore prosthesisREF: Essential Handbook of Practical Orthopedic Examination, By Dr. Kaushik Banerjee, page 146Bipolar prosthesis is used for total hip replacement (THR) while the Austin Moore and Thompson both are used for hemiarthroplasty. Bipolar prosthesis can be both fenestrated and non-fenestratedAustin Moore is always fenestratedThompson is always non fenestrated Austin mooreThompsonPartsHead, neck, collar, shoulder, stemHead, neck, collar, stem (no shoulder)FixingWithout bone cementWith bone cementExtractionEasierVery difficultStem fenestrationsTwo in numberNilCollar holePresent (to check position)AbsentSelf-lockingPresentAbsentWeightLight weightHeavierUsed whenCalcar femorale > 1.25 cmCalcar femorale <1.25 cm', 'role': 'assistant'}]