Arthritis of the Thumb
Arthritis is an inflammatory condition of the joints. There are several types of arthritis; the most common type is osteoarthritis or wear-and-tear arthritis that affects the joint at the base of the thumb. Thumb arthritis is more common in women than men, and usually occurs after the age of 40 years. Patients who have arthritis of the fingers may have swelling, pain, stiffness, and malformation all of which interfere with the use of the hand.
Finger and Thumb Sprain
Injuries that involve tearing or stretching of the ligaments of your fingers are termed as sprains. Sprains in the fingers are most often caused from a fall when you extend your arms to reduce the impact of the fall, or from overuse or repetitive activity of the thumb such as with texting.
Gamekeeper's thumb, also known as skier's thumb, is a tear of the ulnar collateral ligament, a band of tissue that supports the joint at the base of the thumb. Damage to the ulnar collateral ligament may lead to chronic instability of the thumb, creating problems in its normal functioning. Gamekeeper's thumb can result from sports activities (while stopping a ball with a bare hand) or a fall on your outstretched thumb (especially while holding onto something like a ski pole).
Extensor Tendon Injuries
Tendons are bands of tissue connecting muscles to bones. The extensor tendon is a strong, smooth cord that connects finger bones to muscles in the hand. Extensor tendons are located just under the skin, directly on the bone, on the back of the hand and fingers. They allow you to open your hands and move or straighten your wrist, fingers, and thumb.