Degenerative joint disease of the knee is also known as osteoarthritis (OA). OA occurs when the cartilage that cushions your knee joint gradually deteriorates. Your odds of developing OA of the knee increase with advancing age, being overweight, having had previous injuries to the joint, and having a genetic predisposition to the development of OA. Osteoarthritis is a degenerative disease that worsens over time. Symptoms can include joint pain, stiffness, or a sense of grinding in the joint.
Osteoarthritis is diagnosed by physical evaluation and x-rays. An MRI is not commonly required for this diagnosis. There are things you can do to slow the progression of joint deterioration including staying active and maintaining a healthy weight. Other conservative measures include use of viscosupplementation injections which may use steroid medication to decrease inflammation and relieve pain or may use hyaluronic acid to provide joint lubrication. These lubricating injections include Synvisc, Euflexxa, and Zilretta, to name a few. The doctor may also recommend use of a non-steroidal anti-inflammatory medication. A physical therapist can provide pain-relieving treatments such as ultrasound or electrical stimulation and will teach you exercises to stretch tight muscles, improve joint stiffness, and strengthen the muscles that support the knee.
Once the osteoarthritis progresses to the point that conservative treatments no longer provide relief of symptoms, surgical intervention may be an option. In joint replacement surgery, the surgeon will remove the damaged joint surfaces and replace them with plastic and metal parts. This type of surgery typically requires an overnight hospital stay. If you are diabetic, it is important to maintain healthy sugar levels after surgery to decrease likelihood of developing adhesive capsulitis (frozen knee). Smoking also increases your risk of developing this issue. Adhesive capsulitis sometimes requires an arthroscopic surgery to release scar tissue that is keeping the knee from bending and straightening properly.
Rehab following knee replacement is extremely important for regaining full range of motion at the knee and to help you achieve good mobility. If you rest and try to avoid pain in the days and weeks after surgery, you will likely end up with a very stiff knee and have difficulty performing mobility tasks such as stair climbing and getting out of a chair. In the first days after surgery, it will be painful to move the knee. If you push through the pain to perform your range of motion and stretching exercises, these exercises will actually provide relief of pain and of stiffness with activity. In addition, the doctor may order a continuous passive motion (CPM) machine that will be used for a total of 6 hours per day in 2 hour increments. This machine will passively bend and straighten your knee.
The most common complaint after knee replacement is that the new knee gets very stiff after a period of rest. The best way to limit this stiffness is to keep the knee moving and stay active during the day. If you are homebound, physical therapy services can be provided in your home. If not, you can be treated on an outpatient basis. People who are compliant with their exercise program and with use of the CPM machine are typically discharged from physical therapy within 4-8 weeks of surgery.