As you have discovered from your injury, your leg appears round on the outside but the knee actually has corners. Inside your knee are complex bony and soft tissue structures in a location referred to as a corner. Injury to any of these “corners” that goes untreated can create a painful, unstable knee even after surgery for the presenting knee problem.
There are two corners in the front (anterior) and two in the back (posterior. Then add one from each side: medial (side closest to the other knee) and lateral. Combining front and side and back and side gives us corners named anteromedial, anterolateral, posteromedial, and posterolateral.
The corners of the knee are made up of a very complex system of soft tissues woven together. The way in which they share the load makes an injury of one ligament likely to affect the function of others as well. Sometimes where one ligament ends and another begins is impossible to tell. Likewise, many of the ligaments are attached to the joint capsule surrounding the joint (or to the joint itself) in very unique ways. Connective tissue called fascia is also part of the soft tissue structures that helps hold everything together at each corner.
Early surgery has been shown to have better results compared with delayed procedures. And reconstruction of the corner (rather than just attempting to repair the damage) is more likely to be successful. With reconstruction, there is more knee stability, better function, improved range-of-motion, and less risk of arthrofibrosis (stiff knee from fibrous adhesions).
Each surgeon may vary a bit in how and when postoperative recovery and rehab plays out. After surgery, patients are usually in a cast that holds the knee straight and allows for minimal weight-bearing. This period of immobilization lasts about four weeks. During that time, patients are allowed to do leg raises but active knee motion doesn’t begin until the cast comes off in a month. Then the serious business of rehabilitating the knee begins.
A physical therapist supervises a program of active motion, strengthening, and for athletes a return to sports. Most athletes are back to 80 per cent of quadriceps strength between six and nine months. But for some, full return to a pre-injury level of function can take up to a year or more. Manual laborers follow these same guidelines. Your recovery may also be influence by your age, level of preinjury condition, presence of other health problems, or complications that may occur associated with the surgery.
This protocol for rehab and timeline for recovery will give you a general idea of what to expect. Ask your surgeon for his or her recommendations and predictions as well.