Knee osteoarthritis in obesity. Frontal X-ray of the knees of a 67-year-old obese woman in a standing position. The patient weighs 92 kilograms. The narrowed spacing of the femoro-tibial joints indicates the presence of osteoarthritis. The condition has been caused by the patient's obesity. Osteoarthritis is a joint disease aggravated by mechanical stress. Symptoms include joint pain, stiffness and swelling.