Why Finger Joints Click, Snap, and Pop

Rest assured that the most common causes of finger popping is not a problem at all. Many people can make their fingers pop, often called cracking their knuckles. The sound you hear is thought to be caused by air bubbles moving in the fluid that surrounds your joints. When there is no pain associated with finger popping, it is seldom a problem and really harmless. That being said, if your noisy finger joints are associated with pain or swelling, it's good to see your doctor for an evaluation.

Tendon snapping is usually the result of a trigger finger. The tendons in your fingers are like ropes that attach to the ends of your fingers. When your forearm muscles contract, the tendons pull the fingers into a fist. The tendons run part of their course through a sheath called the flexor tendon sheath. In patients who have a trigger finger, this mechanism of movement of the tendon within the sheath is not smooth.

Each finger tendon sheath is a thin tube that runs from the mid-palm towards the end of the finger.  The sheath is reinforced in several locations; this reinforced part of the sheath is called a pulley.  The first pulley on the tendon sheath (called the A1 pulley) is the location where a trigger finger is getting hung up.  In patients with a trigger finger, this is the location of pain when pressed in the palm of the hand.

The cause of trigger finger is often unclear, and can seemingly appear from nowhere. It can occur in one or more fingers, and can occur at different times in different locations. Trigger finger results from a discrepancy between the size of the tendon and the size of the entrance to the tendon sheath. This discrepancy can be the result of localized inflammation or a nodular swelling on the tendon itself.

When the size discrepancy between the tendon and the tendon sheath reaches a critical point, the tendon will experience resistance from the tendon sheath. At first, this is felt as a snapping of the trigger finger when relaxing a fist. If the condition worsens, the trigger finger may need applied pressure from other fingers to straighten, or may not straighten at all.

Trigger finger is about 6 times more common in women than in men, and much more common in individuals with diabetes or rheumatoid arthritis. There has also been speculation that other factors such as genetic predisposition and occupational use can increase the chance of developing a trigger finger.

Trigger finger treatments may consist of simple steps, injections, or surgery. Often people start off with something simple, and if the symptoms persist or return, a more invasive treatment may be recommended. Some of the simplest treatments include splinting of the affected digit, physical therapy, and giving the problem some time to see if the symptoms resolve. 

Ligaments hold joints together and are often damaged when a finger is sprained or dislocated. The ligaments can be partially or completely torn. Common symptoms of a ligament injury include pain along the side of a joint after injury, and swelling of the joint. If the ligament heals improperly, the joint may pop or snap during bending.

In addition, if the ligament heals in and in proper position or with chronic laxity making it too loose, the joint can pop and snap as you bend the fingers. Often times ligament injuries to the fingers are initially thought to be of minor significance, but if not properly treated, they can lead to chronic, long-term problems with the finger joints. For this reason, any suspected ligament injury should be evaluated by a medical professional to determine if further evaluation or treatment is needed.

Finger osteoarthritis can cause the wearing away of the normal smooth cartilage surfaces of the joints. As arthritis worsens, joint movements can become limited and painful. Arthritic joints in the fingers often cause swollen, "knobby" knuckles.

Finger arthritis can cause popping and snapping as a result of small bone spurs around the arthritic joints. The joints may pop or snap because of uneven surfaces or alignment abnormalities. Patients may notice a small bump around the arthritic joint called a mucous cyst.

It is interesting to note that osteoarthritis of the hand is more common in women over the age of 50, and there is also a strong genetic component linked to it. This means that having a parent with osteoarthritis of the hand (especially the one who is the same gender as you) appears to increase your risk of developing it. 

Other factors that increase a person's chance of developing arthritis in the hand include a history of manual labor or repetitive use of the hand. Smoking and handedness may also play a role, but it is not as clear. 

Finger snapping, popping, and clicking has not been shown to be a cause of arthritis, despite what you may have been told—a common misconception. However, that is not to say that finger clicking is never a problem.

The most common sign of a problem that is related to snapping or clicking is pain associated with the noise. So if you have a click or a snap in your finger, and it hurts when the click or snap occurs, it is worthwhile to have the finger checked by your doctor. Sometimes there are simple solutions to these problems and others that may require more invasive treatments.