Patient: Hello, doctor! I am 30 years old, and I had a reconstruction surgery of the ACL of my left knee a year ago, and then a week later I had a pulmonary embolism, which was cured. Now I would like to ask you: 1. If I have another nail removal surgery, is there any risk of thrombosis or not? If so, are there any measures to prevent thrombosis? 2.If the nail is not removed, is it good to keep the nail (polyethylene) in the body and what are the disadvantages? (Is it better to remove the nail or not?) 3.If the nail is removed, is there any requirement on the time limit? Some doctors say it is best to remove the nail within a year to a year and a half after surgery. 4. I have weakness and muscle atrophy in my left leg, so how should I train for recovery? Doctor: 1. There is no particular requirement about the time to remove the nail, usually one year after surgery. Due to the short operation time, it is unlikely to get blood clot after the operation. 2, according to the different fixation materials have the following options: Of course, if it is a metal nail, it is better to take out. If it is an absorbable material nail, basically do not need to take. If the nail is made of polyethylene and there is no discomfort below the front of the knee, it can be removed. If there is significant pressure and pain at the eye of the nail below the wound, it can be removed. 3, whether the need for simultaneous arthroscopy has the following options: If there is obvious discomfort in the joint, and daily activities affect more, you can do arthroscopic exploration at the same time to clean up the lesion. Lumbar anesthesia with a tourniquet may be required. If there is no obvious discomfort in the joint, and all movements are normal, arthroscopic exploration is not needed, local anesthesia to pull the nail can be done without a tourniquet, basically there will be no thrombosis, while the impact on the function of the joint and lower limbs is small. 4, the strength is weak, of course, to strengthen muscle strength exercises!