Some conditions cause the finger or toe joint tissue to thicken, which makes movement difficult. This, in turn, may affect how the joint bends, leading to a locking sensation. The potential causes of this include injury and arthritis.
Tendons surrounding the finger and toe joints control the movement of the digits. A sheath, called the synovial membrane, encloses the tendons. If the synovial membrane becomes inflamed, it can affect the tendon’s movement. The tendon may become stuck on the sheath and cause a finger or toe joint to lock in place.
This article discusses what finger and toe joint locking is, other associated symptoms, causes, and treatments alongside lifestyle measures that may help prevent or manage it.
People also refer to locking or catching of the joints in the digits as stenosing tenosynovitis. When this occurs in the finger joints, people also call it “trigger finger,” but it can affect any finger joints.
Tendons are cord-like structures that attach the muscles to bones. When a specific muscle contracts, the flexor tendons pull on the bones of the fingers or toes, which
Flexor tendons run from the forearm to the fingers’ ends across the palm. Each flexor tendon that leads to a finger or toe is encased in its structure, called a sheath. The sheaths attach to the finger and toe bones.
The bands of tissue — a pulley — sit along the sheaths, which hold the tendons near the bones as they flex and stretch.
In people with stenosing tenosynovitis, the pulley thickens, which makes it harder for the tendon to move, which in turn causes difficulty bending the joint of the finger or toe. The tendon may eventually become inflamed and develop nodules on its surface. When this happens, the bumps can catch on the pulley and cause a locking sensation.
Symptoms of stenosing tenosynovitis may occur after someone uses their hand for repetitive activities or may develop gradually due to other causes. Symptoms include:
- a digit, usually a finger, becoming locked in a bent position
- a popping or catching feeling when bending the digit
- pain when straightening or bending the digit joint
- a sensitive or painful lump at the base of the digit
- stiffness in the joint, especially upon waking, which may ease throughout the day
Doctors do not know the exact causes of finger and toe joint locking, but various risk factors can increase a person’s chances of developing the condition. Associated conditions
- Rheumatoid arthritis (RA): An autoimmune disorder in which the immune system mistakenly attacks healthy cells in the joints, which
causesinflammation in the fingers and toes.
- Gout: Crystals build up in the joints and affect their movement. Gout
typicallyaffects the big toe.
- Carpal tunnel syndrome: This occurs when the median nerve in the hand is compressed and can cause pain, numbness, and tingling.
- Issues affecting the thyroid: Conditions such as hyperthyroidism and hypothyroidism can affect the structure and function of the muscles and joints.
- Amyloidosis: This occurs when specific proteins in the body build up into deposits in the tissues and organs. This protein buildup could cause pain in the joints.
2021 researchshows that people with amyloidosis commonly report trigger fingers. Further research must determine how the diagnostic process can help reduce the risk.
- Diabetes: This chronic condition affects how the body breaks down glucose from food and turns it into energy. Trigger finger is a possible complication that may affect people with diabetes, and medical professionals will consider these factors during diagnosis.
- Injury or trauma: For example, dislocation, when a bone slips out of its joint.
- Developmental: A child’s flexor tendon and sheath may not match in size, referred to as a pediatric trigger finger.
Certain pathogens may result in infective tenosynovitis due to injury or the spread of infection. A
A person should consult a doctor if they suspect infection to receive a prompt diagnosis and determine the type of organism and treatment.
Infectious tenosynovitis treatment varies based on the type of organism. Doctors will usually prescribe a course of antibiotics with its duration depending on the severity of the infection.
For early signs of infections, other possible treatments include sheath irrigation — cleaning the tendon sheath — and catheter-directed therapy. Debridement may be an option for people with late stages of infection, where doctors remove debris from an infected area.
Treatment for joint locking in the finger or toe depends on the cause and severity of the condition. It may include:
- resting the joints and avoiding activities that could worsen the condition
- performing gentle stretching exercises to help with stiffness and improve range of motion
- taking over-the-counter (OTC) medication to help with pain and inflammation, such as nonsteroidal anti-inflammatory drugs (NSAIDs)
- wearing a splint, especially while sleeping
- having a corticosteroid injection, which can reduce inflammation
- undergoing surgery, in some cases, to release the affected pulley and allow the tendon to glide more easily, which should stop the locking sensation in the digit
A person may develop joint locking in the digits from repetitive activities. Avoiding or modifying repetitive activities — especially gripping or pinching hand motions — could help prevent locked joints.
Joints in the digits may lock when the membrane surrounding the tendons — the synovial sheath — becomes inflamed. This inflammation can cause difficulty bending or straightening the joint and cause a catching or locking sensation, which can be painful.
Experts do not know the exact causes of joints in the fingers and toes locking, but they associate joint locking with several other conditions. These include RA, carpal tunnel syndrome, diabetes, and injuries such as dislocation.
People can treat joint locking in the digits with OTC medication, gentle stretching, rest, or splinting. In more severe cases, a doctor may need to administer a steroid injection, or a person may require surgery.