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
Which of these muscles undergoes wasting first in osteoarthritis knee- 
Select and explain. 
A. Quadriceps only, B. Hamstrings only, C. Gastronemius, D. All of the above
A: Quadriceps only
Answer: A: Quadriceps only 
Explanation: Muscle atrophy particularly involves the quadriceps muscle.
All periarticular muscles around the knee joint may undergo wasting in advanced osteoarthritis knee.
However muscle atrophy particularly involves the quadriceps which is the earliest muscle to undergo wasting.
In patients with osteoarthritis knee, quadriceps strengthening exercise form an important management component to protect the articular cartilage from stress.