When preparing for total knee replacement surgery, certain tests and examinations are performed. A medical evaluation is necessary to assess your health and identify any conditions that could interfere with surgery or recovery. Any of the following tests may be performed: blood and urine samples, cardiogram, X-rays. Before surgery it is important to make sure skin is free of infection and irritations. You may be advised to donate blood before surgery in the event you need blood after surgery. Your doctor will advise you which medications to stop taking and which to continue taking before surgery. If you are overweight, you may be asked to lose weight to minimize the stress on your new joint and decrease the risks of surgery.
During total knee replacement surgery, the knee is in a bent position so that all the surfaces can be exposed. The usual approach is to make the incision lengthwise over the front of the knee, or just to the inside of the kneecap. After the incision is made, the quadriceps muscle and the patella are moved to the side to reveal the bone surfaces. The remaining cartilage, misshapen bone and the meniscus are removed during surgery. Cutting guides are used to accurately trim the damaged surfaces at the end of the femur in order to shape the bone to match the inside of the implant component. The tibia is cut flat across the bone and a portion of the bone’s center is drilled out. The surgeon removes just enough of the bone so that when the prosthesis is inserted, it recreates the joint line at the same level as before surgery. The surgeon will release any ligaments that have contracted so they function as close to normal as possible. Before the final implants are inserted, trial prostheses are inserted to check the correct position and mobility of the knee joint. The final implants are then inserted, tested, and balanced. If necessary to resurface the patella, the surgeon will apply a dome-shaped piece of polyethylene that maintains the original width of the patella.
Hospital stays vary, but after total knee replacement surgery patients typically are in the hospital three days. This depends on how well you recover after surgery. Your rehabilitation will begin in the hospital. A physical therapist will help you learn how to use your new knee.
Before going home you must meet several goals:
- Get in and out of bed by yourself
- Bend your knee approximately 90° or show good progress in bending your knee
- Extend your knee fully
- Walk with crutches or a walker on a level surface
- Climb up and down 2 or 3 stairs
- Perform the prescribed home exercises
Once at home, it is important to keep performing the exercises you learned while in the hospital. Activities that are particularly good after knee replacement surgery include regular walks, gentle physical activity, cycling and swimming. Impact stress should be avoided, as well as crouching or kneeling, compression stress, lifting or carrying heavy weights, over-straining or over-exertion.
It is important to properly care for your incision site. Avoid soaking wound in water until the wound has thoroughly sealed and dried. The wound may be bandaged to avoid irritation from clothing or support stockings.
Some loss of appetite is common for several weeks following your surgery. A balanced diet is important to promote proper tissue healing and to restore muscle strength.