Feb 19 (Reuters) - Johnson & Johnson is preparing a potential sale of the orthopedics unit that it has ‌been planning to separate, with big buyout firms already ‌circling, Bloomberg News reported on Thursday, citing people familiar with the matter. The ​business, known as DePuy Synthes, could be valued at more than $20 billion in a sale, according to Bloomberg. The company did not immediately respond to a Reuters request for comment. J&J last year ‌said it had planned ⁠to separate its orthopedics busi ...