Pain in the hand can be caused by many things – by overuse, an injury, a trapped nerve or some kind of a disease. Here we will focus on the pain that is located at the thumb joints. It can either be due to traumatic or degenerative causes, can occur immediately or more gradually, and can have a big negative impact on our everyday activities. We will try to explain the nature of the pain and how it can be treated. First, let us take a look at the joints in the thumb. They are three:
- Carpometacarpal (CMC) joint (thumb basal joint)
This joint is placed at the point where the thumb connects with the wrist (carpo – wrist; metacarpal – hand bone). Its main purpose is to help the thumb open and grasp objects. The carpometacarpal joint commonly suffers from a type of osteoarthritis called basal joint arthritis or also thumb arthritis.
- Metacarpophalangeal (MP) joint
This is the middle thumb joint which is situated between the carpometacarpal one and the tip of the thumb (metacarpo – hand bone; phalangeal – finger bone). This joint could be injured if you slam your thumb while doing sports, for example skiing, and this condition is sometimes called skier’s thumb.
- Interphalangeal (IP) joint
This joint is located at the tip of the thumb (interphalangeal means between finger bones). If you jam the tip of your thumb, you could rupture a tendon and given that tendons are responsible for joint movement, the interphalangeal joint may lose its ability to move normally.
Now, let us take a look at the conditions that cause thumb joint pain.
- Bone injury (joint fracture)
Usually, you can get your thumb joints fractured when you fall on your outstretched hand, while doing sports activities. You experience sharp pain which gets worse when you try to move your thumb. Fractures at the end of a bone can be serious as they may limit your ability to move the joint. Sometimes you need to undergo surgery in order to stabilize the bone until it heals.
- Bennett Fracture
This is the most common fracture involving a thumb joint. It is caused if you fall on your thumb or get it injured when punching a hard object. This fracture comes with severe pain and swelling in the joint.
- Rolando Fracture
This fracture is even more severe than the Bennett one as it consists of several small pieces. Although it is a relatively rare one, it always requires an operation and the pain in the joint may persist for months.
- Extra-articular Fracture
This is a simple fracture of the shaft of the small bones present in the thumb, called phalanges. It does not need a surgical intervention and does not cause huge pain and suffering.
- Ligament injury
A ligament is a fibrous connective tissue that attaches bone to bone. There are two main ligaments that support the base of your thumb – the ulnar collateral and radial collateral ligaments. When you damage a ligament, a sharp pain is felt at the joint where the thumb meets the hand.
- Skier’s thumb
This is an injury to the ulnar collateral ligament of the MP joint which is the ligament that supports the thumb when pinching or gripping. If damaged, the thumb may become chronically unstable. This injury gets its name skier’s thumb because you may get it when you fall onto your thumb while gripping something and that could be a ski pole. At times there is no specific injury, only chronic stretching of the ligament – a ‘gamekeeper’s thumb’. The method of treatment is decided based on whether the ligament is partly or completely torn. If the ligament is partially torn, the patient wears a splint or cast for about a month and a half and after they remove it they do special exercises that are meant to get the thumb to move again. If the ligament is completely torn, the patient undergoes an operation to repair it. The desired outcome is generally for the ligament to heal and the thumb function to return to normal. Unfortunately, that does not always happen.
- Tendon injury
A tendon, like a ligament, is a fibrous elastic connective tissue, but while a ligament connects bone to bone, a tendon connects muscle to bone. In the thumb, the tendons connect close to the joints to bend or straighten the tip and base of it, and to move the base from one side to the other. Sometimes the tendons could become inflamed and so they start to swell and provoke pain in the thumb. When a tendon is torn from an injury, pain is felt at the joint that is closest to the tip of the thumb (that is, the interphalangeal joint) and you will notice you cannot bend or straighten it. You have to seek medical help immediately as you will most like need surgery.
Dislocation can occur even if there is no thumb ligament fracture. When there is one, it is called a fracture-dislocation of the thumb. Dislocation is more usual at the base of the thumb (the CMC joint) and generally leads to difficulty to move the thumb, rather than instability that occurs in other injuries. There is less swelling and less pain.
Degenerative causes: osteoarthritis in the thumb joint
There are several types of arthritis that affect the joints. We will take a quick look at the most usual one in the hand, the one that commonly affects the joint at the base of the thumb (the CMC joint) – the degenerative arthritis or also called osteoarthritis, and in this case, due to the location –thumb arthritis or basal joint arthritis. In a healthy joint, bone ends are covered in cartilage that makes for their smooth and painless movement against each other, but with osteoarthritis, the cartilage layer wears out with time and the bones rub against one another. This condition is more common in women over the age of 40, and the chances of getting it are increased by prior fractures.
The symptoms of osteoarthritis include pain and swelling at the base of the thumb, weakness, stiffness of the thumb, difficulty holding objects, etc. In severe cases, a bump develops at the base of the thumb.
Treatment for thumb arthritis could either be surgical or non-surgical. Non-surgical treatment is applied at the early stages of the degenerative condition and involves icing the joint to decrease swelling; taking anti-inflammatory medications prescribed by your doctor; small changes at home such as using bigger pens and changing door knobs to latches; wearing a supportive brace to ensure the thumb is in a resting position; and limited use of corticosteroid injections to alleviate pain. Surgery is performed when conservative management is no longer effective and the condition has progressed. It has to be performed based on the patient’s personal needs and could involve repositioning the bone to take pressure off the joint (osteotomy); fusing the bones of the joint together (arthrodesis); or removing part of the joint and reconstructing it (arthroplasty). After the surgery, you will have to wear a thumb splint or brace for one to two months. After that, you will have to consult a hand therapist to work on regaining thumb flexibility.
Pain in the thumb joints can be very hard to bear and can have different causes. It is important to contact your GP for advice whenever you feel like it and be careful not to hurt yourself while doing sports. Some of the conditions are more serious than others and can lead to years of discomfort so it is important to “catch” them before they have developed and start the right treatment right away.