In most cases, pre-surgical rehab is just as important as post-surgical rehab. Strengthening the muscles and conditioning the body to its optimal level prior to surgery will make post-surgical rehab easier and can improve the speed of your recovery. This holds true for many types of surgeries, such as a total hip/knee replacement, rotator cuff repair, ACL reconstruction, etc.
Post-surgical rehab is highly recommended and typically necessary following a surgery. From a meniscus repair to a total shoulder replacement, physical therapy will perform a thorough evaluation and put your goals first when creating a comprehensive program to get you back to your prior level of function.