This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Orthopaedics
Severe disability in primary osteoarthritis of hip is best managed by - 
Select and explain. 
A. Arthrodesis, B. Arthroplasty, C. Mc Murray's osteotomy, D. Intra-articular hydrocortisone and physiotherapy
B: Arthroplasty
Answer: B: Arthroplasty 
Explanation: The primary aim of surgery is relief of pain, while secondary aim is to restore movements, increase stability deformity correction.
In early stage when a fair amount of hip movements is still present, osteotomy may be used.
However, in severe arthritis with functional disability, arthroplasty provides best results and significantly improves daily functioning. Total hip replacement (THR) is most commonly used arthroplasty of hip.