WendiS,
It is not uncommon for the posterior capsule to ache or hurt after any surgical procedure on the knee. During an arthroscopy, the knee joint is distended with fluid and as such the capsule is stretched for a period of time.
Often, after surgery patients will drape the knee over a pillow, in a flexed position. Unfortunately, this is not a very good way to elevate the knee. After surgery or injury, the knee should be elevated in a straight line, with the knee fully extended. The pillows should be placed under the ankle.
This position keeps the posterior capsule and other posterior tissues from becoming contracted. If they become contracted, then full extension is very difficult to achieve. If the knee cannot be fully extended, the patients will then have to walk on their toes, rather than in the normal heel to toe manner. Also, a contracted posterior capsule will hurt when it is being stretched out.
But, it is a damned if you do, damned if you don't. Because, if you keep the posterior capsule on stretch, to keep it from becoming contracted, the constant stretch can cause aching also. So, what is a patient to do?
Usually, as time goes by, the aching in the posterior capsule goes away. But, to help that, you want to try to keep the swelling in the knee to a minimum, as an effusion will distend the capsule again. And, with the microfracture, the surgeon wants the area to bleed, to produce fibrocartilage in the articular cartilage defect. But, this causes more swelling in the joint.
So, ice, elevation, and compression are very important. Ice as much as possible and keep the knee elevated about the heart whenever possible. If you use a compression wrap, make sure it is providing concentric compression, but that it is not too tight, causing edema to collect distal to the wrap. It is usually best to use two or three ace wraps, starting from the toes and wrap all the way up to the groin. This way circulation won't be cut off. The other way to provide compression is to use the surgical TED hose or support hose.
If the surgeon says it is okay, and you can take them, NSAID medicine will also help to keep the swelling down.
Hope the discomfort goes away shortly and you can begin your rehab. Good luck.