If you are considering knee surgery the following total knee replacement information might help you understand the procedure better.
Your knees work hard during your daily routine, and arthritis of the knee or a knee injury can make it hard for you to perform normal tasks. If your injury or arthritis is severe, you may begin experience pain when you’re sitting down or trying to sleep.
Sometimes a total knee replacement is the only option for reducing pain and restoring a normal activity level. If your and your doctor decide a total knee replacement is right for you, the following information will give you an understanding about what to expect.
A total knee replacement involves trimming the damaged bone of the knee joint and replacing it with a prosthesis. This “new joint” prevents the bones from rubbing together and provides a smooth knee joint.
In the total knee replacement procedure, each prosthesis is made up of four parts. The tibial component has two elements and replaces the top of the shin bone or tibia. This prosthesis is made up of a metal tray attached directly to the bone and a plastic spacer that provides the bearing surface.
The femoral component replaces the bottom of the thigh bone or femur. This component also replaces the groove where the patella, or kneecap, sits.
The patellar component replaces the surface of the knee cap, which rubs against the femur. The patella protects the joint, and the resurfaced patellar button will slide smoothly on the front of the joint.
Pre-operative Testing & Consultation
You and your orthopedic surgeon participate in an initial surgical consultation. This appointment may include preoperative X-rays, a complete medical and surgical history, physical examination, and comprehensive list of medications and allergies. During this visit, your orthopedic surgeon will review the procedure and answer any questions you may have.
This class, taught by the multidisciplinary total joint team provides detailed information regarding all phases of your joint replacement experience. Members of the orthopaedic surgical, nursing, physical therapy, and discharge planning staff answer any questions that you might have regarding your joint replacement plan of care. It is highly recommended that you make plans to attend a preoperative class. They are offered weekly and take place on the post operative orthopaedic surgical floor in the hospital so you will have a chance to become familiar with your post op surroundings. You are encouraged to bring someone with you who will be assisting you after your surgery on your return home.
Your orthopedic surgeon may ask you to consult a physical therapist to discuss the recovery period, rehabilitation program, and important precautions, as well as instruct you in exercises that you can begin prior to surgery that will make the recovery much easier.
Finally, maintaining good physical health prior to surgery will also improve the recovery period and overall post-operative outcome.
Preparation for the Hospital
You may want to bring the following items to the hospital for your knee replacement surgery:
Clothing: underwear, socks, t-shirts, exercise shorts for rehabilitation.
Footwear: walking or tennis shoes for rehab; slippers for hospital room.
Walking aids: walker, cane, wheelchair, or crutches if used prior to surgery.
You should follow your regular diet on the day before your surgery. Do not eat or drink after midnight.
Follow your doctor’s instructions regarding use of medication in the days leading to surgery. Finally, try to get a long, restful night’s sleep.
Day of Surgery
On the morning of the surgery, you will be admitted to the hospital and taken to the appropriate pre-surgical area. The nurse will spend a few minutes preparing you for surgery by taking your vital signs, starting IV fluids, and administering medications as needed. You will be asked to empty your bladder just prior to surgery, and to remove all jewelry, contacts, dentures, etc. You will change into a hospital gown, be placed on a stretcher, and transported to the operating room. The anesthesiologist will meet you and review the medications and procedures used during the surgical case.
Anesthesia will be either general or spinal. With a general anesthetic you are asleep and with a spinal your legs and hips are numb allowing you to have the operation without pain. Patients who receive spinal anesthesia are given intravenous medication during the procedure to allow them to remain comfortable and relaxed.
The surgeon will begin by making an incision in your leg to allow access to the knee joint. He’ll then expose the joint and place a cutting jig or template on the end of the femur, or thigh bone. This jig allows the surgeon to cut the bone precisely so that the prosthesis fits exactly. Once the femur is cut, the tibia is cut using another jig for proper alignment of the knee prosthesis. The undersurface of the patella is then removed.
Now it’s time to place the prosthesis. This begins with the femoral prosthesis, which is cemented in place using a special bone cement. Next the metal tray is attached to the top of the tibia. This will provide the weight-bearing surface of the femur. The plastic spacer is then attached to the metal tray. This will provide the weight-bearing surface of the femur. If this component should wear out while the rest of the artificial knee is sound, it can be replaced. This is known as a “revision.” Next the patellar button is cemented in place behind the knee cap. Finally, the incision is closed, a drain is put in, and the post-operative bandaging is applied.
You will be discharged when you can get out of bed on your own and walk with a walker or crutches, walk up and down three steps, bend your knee 90 degrees and straighten your knee.
At home you should begin ambulation with a cane as tolerated. Keep your incision clean and dry and watch closely for any signs of infection.
You’ll continue your home exercise program and go to outpatient physical therapy, where you will work on an advanced strengthening program and such programs as stationary cycling, walking, and aquatic therapy.
Your long-term rehabilitation goals are a range of motion from 100-120 degrees of knee flexion, mild or no pain with walking or other functional activities, and independence in all activities of daily living.