Osteoarthritis, or "wear and tear" arthritis, is a common degenerative disease that can affect any joint in the body. Arthritis in the thumb affects the joint at the base of the thumb, which becomes inflamed when the smooth cartilage (cushioning) at the end of the bones begins to wear away, causing friction. Symptoms include pain, swelling and immobility. If left untreated, the bones that make up the thumb can lose their normal shape, resulting in more pain and less mobility. Typically seen in older people, the condition usually comes on gradually over time, and injury such as a fracture can increase the chance of developing it. Diagnosing Osteoarthritis of the Thumb Physical Exam Your physician will ask you a series of questions and is likely to do a physical exam. The physical exam will including examining any specific areas of concern, especially as they relate to the reason for your visit to the office. X-Rays A form of electromagnetic radiation with very high frequency and energy. X-rays are used to examine and make images of things such as the bones and organs inside the body. MRI This test uses a magnetic field, radiofrequency pulses, and a computer to produce detailed images of body structures in multiple places. You may be injected with a contrast agent for better imaging, and you will most likely lie on a moving table as pictures are taken. MRI is a more detailed tool than x-ray and ultrasound and for certain organs or areas of the body, it provides better images than CT. MRI may not be recommended if you have a pacemaker or other metal implants. Blood Tests A common tool for disease screening, blood tests provide information about many substances in the body, such as blood cells, hormones, minerals, and proteins. Treatments for Osteoarthritis of the Thumb Bracing/Splinting A splint, also known as a brace, is a rigid device that holds a body part in place so that it is unable to move. It is usually used as a treatment for a suspected fracture, sprain/ligament damage, or other injury. It can be applied by first responders in the event of trauma. Splints can reduce pain, aid in proper healing, and can also prevent further injury. They can be worn for several days or weeks to hold the body part in place for the duration of healing time. Surgery for Osteoarthritis of the Thumb This is an option when nonsurgical treatment methods are not working for the patient. The operation can be performed on an outpatient basis, and several different procedures can be used, including bone fusion, or removing part of the joint and reconstructing it using either a part of the patient's own tendon or an artificial substance.