Arthritis of the knee is a disease process involving destruction of the normal cartilage gliding surfaces. Degeneration or, "wear and tear," is by far the most common cause. This usually occurs over time, but can result from trauma or injury. Another cause is rheumatoid arthritis, which involves the aggressive attack of the cartilage by the body's own immune system. Either of these processes ultimately lead to varying symptoms of pain, stiffness, swelling or instability.
Early management with anti-inflammatory medications can often be helpful. Basic anti-inflammatories include Ibuprofen, and Naproxen. Numerous types of prescription medicines are also available, often chosen to help minimize stomach side affects.
Physical therapy has an occasional role in the disease process. The main emphasis is on maintaining, and building strength of the thigh muscle (quadriceps). Ice can be helpful to reduce inflammation, and is applied ten to fifteen minutes up to three to four times per day.
A cortisone injection often combined with a local anesthetic can sometimes help to decrease inflammation, and can be done two to three times in a year if helpful and needed.
A cane is beneficial for mechanical support, best used in the opposite hand.
Visco supplementation (Hyalgan, Synvisc) is a protein injected once a week for three to five weeks. This may act to decrease inflammation, and help the cartilage improve gliding properties.
When one's symptoms persist despite various failed non operative attempts at treatment, and one's quality of life is severely impacted the patient may be a candidate for an elective total knee replacement.
The results with total knee replacement have become quite reliable and reproducible. Good results are expected about 90 to 95 % over twelve to fifteen years.
The principles of knee replacement involve the removal of about one centimeter of bone from the end of the thigh bone (femur), upper leg (tibia), and the kneecap (patella).
The femoral component is made of metal (cobalt chrome) anchored with cement or a textured ingrowth surface. The tibial component is made of titanium or chrome cobalt, and be anchored with cement or a textured ingrowth material. The kneecap (patella) is made up of a plastic button, and is anchored to the bone with cement.
Prior to surgery an examination by one's internist or family physician will usually be recommended. Routine preop testing will often include blood test, chest x-ray and EKG. A preoperative session with physical therapy is often helpful.
Anesthesia options include a general anesthetic or a regional anesthetic (epidural or spinal).
The surgical approach to the knee is typically from the front. The incision may be a standard, eight to ten inch incision. Sometimes a minimal incision surgery (MIS) may allow for a four to six inch incision. You may speak with your physician about which approach is most appropriate in your specific case.
Pain medication options after surgery include the PCA (patient controlled analgesia) self-administered computerized pain medication through the IV. If an epidural anesthetic is used, a tiny tubing (catheter) is used and left in place in your back for the first two days. Thereafter, oral medication is used.
Postoperatively a continuous, passive motion machine (CPM) is used. Physical therapy will be initiated the day after surgery to mobilize the patient as quickly as possible. Patients are encouraged to endure discomfort in the early postop period to optimize mobility progress. Weight bearing is allowed with a walker or crutches, and advanced to a cane as soon as the patient is able, usually several weeks.
The hospital stay is expected to be two to four days. Often a rehabilitation stay thereafter maybe beneficial to further strengthening, independence, and safety.
A total joint replacement is a major operation. Complications are not common, but occasionally occur, and sometimes maybe serious. These include:
- Deep vein thrombosis, (blood clot).
- Pulmonary embolus, (clot to the lung).
- Nerve injury.
- Arterial injury.
- Wound healing problems.
- Wearing or breaking of parts.
- Loosening over time which may require re-operation.
- Fracture of the bone on insertion.
- Fracture of the kneecap (patella), dislocation of the kneecap.
- Instability from loose ligaments.
- Stiffness from scar tissue.
Overall, knee replacement procedure is a very safe, predictable, and gratifying operation to restore function and to relieve pain.