Knee Pain

Knee pain that is gradual in onset and not related to an injury is usually osteoarthritis (wear and tear arthritis). Other causes of knee pain include tendinitis, bursitis, infection or tumor. Mechanical symptoms such as locking or catching, and instability due to buckling, catching, or weakness help the physician determine possible causes of the pain. Infection is characterized by warmth, redness, exquisite point tenderness and pain with even a small amount of movement. A joint infection may be a medical emergency and requires prompt evaluation and treatment.

The first imaging technique for non-traumatic knee pain should be regular x-rays. These will show the knee alignment as well as any joint space narrowing.  X-rays will also reveal hidden fractures or tumors. If the initial X-rays are negative, the patient should be given a three to six week trial of conservative therapy: (rest, NSAIDS, ice, compression, elevation, activity modification, physical therapy, crutches).

A MRI can be considered if there is no improvement with conservative therapy. However, MRI alone has little to offer for patients with non-traumatic knee pain, no mechanical symptoms, and findings of degenerative arthritis on plain films.  Because the incidence of abnormal findings such as meniscal tears is high in asymptomatic patients, any MRI finding must be carefully correlated with clinical signs and symptoms. 

Many experts recommend an orthopedic consultation before obtaining a MRI if conservative therapy does not relieve pain. A knee MRI will cost at least $1500, a big consideration in these days of high-deductible health insurance plans. It’s a high ticket item that might not add much to the clinical plan.

The Mayo Clinic has an excellent guide for patients.