It has long been believed that osteoarthritis is a wear and tear disorder. Today, osteoarthritis (OA) is recognized as a complex problem that affects multiple joints. It is characterized by cartilage degeneration, bone remodeling, bone spur formation, joint inflammation, and loss of normal joint function. The knee and hip joints are most commonly affected. Almost 30% of people over age 45 have evidence of knee OA on an x-ray, and half of them have knee symptoms.
Knee OA is the most frequent cause of pain and disability making performance of the activities of daily life difficult, resulting in a poor quality of life. About 21% of adults with knee OA are also diagnosed with depression.
Who is at risk for knee OA?
The causes are unclear, but these factors increase the risk of developing knee OA:
- Being overweight or obese increases the risk of developing knee OA.
- Prior joint trauma such as a torn Anterior Cruciate Ligament or ankle fracture accounts for 12% of knee OA cases.
- Older age and being female increases the risk for hip and knee OA.
- African American women have a higher prevalence of knee OA.
- Abnormal leg alignment increases the risk of knee OA and its progression.
- A family history of knee OA.
- Inflammation contributes to the destruction and remodeling of the knee joint.
- Diseases like diabetes, metabolic syndrome and hypertension have been linked to osteoarthritis.
What are the symptoms of knee OA?
The key symptoms are pain and stiffness in the affected knee that is worse in the morning and after prolonged sitting and improves within 30 minutes. If the cause is rheumatoid or psoriatic arthritis the stiffness lasts over an hour. Other symptoms include altered gait and a crunching or grating sensation when moving the knee.
How is knee OA diagnosed?
Your orthopedic specialist will review your medical history, evaluate your risk factors, and ask about your symptoms. They will perform an orthopaedic examination of the knee testing range of motion, tenderness, swelling, and stiffness. They will order X-rays and may order imaging studies such as an MRI or CT scan to look for damage to all knee structures, or when there is a suspicion of other conditions that may require more urgent treatment. Even if x-rays are normal, initial management of symptoms may be recommended. They will order blood tests to identify other causes of arthritic symptoms.
The classic features of OA seen on an x-ray are narrowing of the joint space due to a loss of articular cartilage and meniscus, bony changes to the underlying bone and bone spurs. An expert clinician at COS must distinguish symptomatic OA from rheumatoid and psoriatic arthritis, infection, and gout, as well as rule out bursitis, tendonitis, and tears of the meniscus to render the correct diagnosis.
What are the treatment options for knee OA?
Options depend on the severity of your condition. Nonsurgical management includes nutrition education, weight loss, exercises such as muscle strengthening can improve pain and function, cardiovascular exercise like walking can reduce pain, and mind body exercises like yoga or Tai Chi. They may refer you to a physical therapist to address weakness and reduced range of motion. Diet and exercise can improve function.
Over the counter and prescription oral and topical NSAIDS (anti-inflammatory medications) are a first line drug treatment for the pain of knee OA. If they cannot be tolerated or have medical conditions that make it unsafe, other prescription drugs may be recommended. Intraarticular injections of steroids can offer short term pain relief. Other joint injections of hyaluronic acid or platelet rich plasma can help to relieve pain. Studies report that an antidepressant called Duloxetine provides good pain relief. Opiates are not generally recommended.
Patients with persistent pain and loss of function are candidates for total knee replacement. A majority of patients who undergo total knee replacement find little to no residual pain after recovery.
Contact the Center for Orthopedic Specialists to schedule a consultation with an expert. We have offices in Mission Hills, Tarzana, West Hills, and Westlake Village for your convenience. You will always be treated with respect and compassion.