Intersection syndrome is inflammation and swelling of tendons in the wrist and back of the forearm. It is a rare form of tendonitis but is more common in people that play sports.
Tendons are thick cords of fibrous tissue that connect muscles and bones. Tendons cross over each other in the wrist, and some actions can make them rub against each other, causing friction. The
Many tendons pass through the wrist in six anatomical tunnels called extensor tendon compartments. The NCBI notes that intersection syndrome (IS) occurs when tendons from the first compartment cross over and rub against those from the second.
This article explains what causes IS and how doctors diagnose and treat it. It also looks at home remedies and how to prevent it.
IS describes a form of tendonitis in a person’s wrist. It starts at the point where two tendons cross over or intersect. According to the
IS is a rare form of tendonitis, most commonly affecting people who repeatedly bend and straighten their wrists. Office workers or anyone else who repeatedly does repetitive motions with their wrists can develop this. However, regularly participating in sports, such as rowing, mountain biking, horseback riding, racket sports, and skiing, may make a person more susceptible to IS.
The repetitive movements cause friction at the point where two tendons that straighten or extend intersect with the fingers and thumb. The rubbing action makes the tendons swell, causing inflammation and pain.
Most people with IS have a painful spot on the back of their wrist, stretching down a little into the back of their forearm. A 2021 paper explains that the pain is usually on the thumb side of the wrist, starting about 0.5 inches (in) below the wrist joint and extending just over 2 inches down the arm.
Many people experience a rubbing sensation when moving a wrist, there may be swelling, and the area may feel warm to the touch. Some people might find that the pain intensifies when they bend or straighten the wrist.
Others find that the wrist squeaks or makes a creaking noise when they move it. Doctors call this crepitus.
People develop IS by overusing the tendons that extend or straighten their fingers. As the tendons pass through the wrist, they overlap, and when they rub against each other, the friction causes swelling.
- racket sports, including tennis and racquetball
- horseback riding
- other repetitive movements
The Hand and Wrist Institute explains that doctors use the location of a person’s pain to help them diagnose IS.
Other forms of tendonitis, including de Quervain’s tenosynovitis, also produce pain in the back of the wrist and back of the forearm, but in slightly different places.
If they are unsure after a physical exam, doctors may recommend imaging tests, such as an ultrasound, or an MRI, to check where the inflammation starts.
Learn more about de Quervain’s tenosynovitis here.
What else could cause the symptoms?
Most people with de Quervain’s tenosynovitis have pain along the outside of their thumb, stretching down into the forearm. People with IS usually feel pain slightly more centrally on the wrist.
Most doctors recommend people with IS stop doing sporting or other activities that aggravate the wrist to give the injury time to heal.
After the initial swelling has gone down, people with IS can start gently stretching and exercising their arm and hand. The idea is to gradually build up the intensity of the exercises over 4–6 weeks until the person has regained their former movement.
Researchers caution against introducing weights initially and advise people with IS to be mindful of their injury when training to avoid any relapses.
If the person’s injury developed due to taking part in a specific sport, they might need to refresh themselves about best practice techniques.
If they experience symptoms again, stopping the activity and resting their arm will prevent the injury from worsening.
Most people with IS fully recover and regain their former movement in the wrist. The
IS is a type of tendonitis in the wrist. It happens when people repeatedly bend and straighten their wrists, making overlapping tendons rub against each other.
The friction between the tendons causes inflammation and swelling, specifically on the back of the forearm, just below the wrist joint.
Doctors usually recommend rest, splinting or bandaging the wrist to support it, and using OTC pain and anti-inflammatory medications as the first-line treatment. If these do not work, they may prescribe corticosteroid injections or, very rarely, surgery.
Most people recover fully and can return to their former levels of activity.