P2. Muscle strength
CONTRACTION, FLICKER
The strength of the non-operative side quadriceps muscle was measured every 15 min after surgery, and when the muscle strength reached grade 4, the quadriceps muscle strength on the operated side was measured and recorded. Muscle strength was determined by testing the movement of the knee or hip joint. Muscle strength was graded as 0, no contraction; 1, muscle flicker; 2, active movement but not against gravity; 3, active movement against gravity; 4, the movement against some resistance; and 5, full strength against resistance.