Written By: Chloe Wilson BSc (Hons) Physiotherapy
Reviewed By: SPE Medical Review Board
Intersection syndrome is a type of wrist tendonitis caused by repetitive friction and overuse.
It causes pain on the back of the lower forearm, due to irritation where two groups of tendons cross-over each other or “intersect”.
Intersection syndrome typically affects people who do lots of repetitive wrist movements, or lots of gripping or lifting. It is common with sporting activities such as rowing, kayaking, racket sports and weight-lifting as well as in construction and manual labor.
The two classic features of intersection syndrome are pain and crepitus on the back of the forearm, just above the wrist, that get worse with wrist or thumb movements.
In most cases, intersection syndrome will settle down with rest, physical therapy, splinting and exercises, but occasionally injections or surgery may be recommended.
Here we will look at what is intersection syndrome, the common causes and symptoms and the best treatment and prevention options.
Intersection syndrome is an inflammatory condition that occurs when there is excessive friction between two groups of tendons on the back of the forearm. These tendons are responsible for movements such as extending your wrist and thumb.
Approximately 4-6 cm above the back of the wrist joint, the tendons of abductor pollicis longus (APL) and extensor pollicis brevis (EPB) cross over, or “intersect”, with the tendons of extensor carpi radialis longus (ECRL) and brevis (ECRB).
Repetitive friction between the tendons at this junction causes pain and inflammation, resulting in Intersection Syndrome. Inflammation develops in the tendon sheath, a layer of connective tissue which surrounds and protect the tendons and helps them to move smoothly, leading to tenosynovitis.
Intersection syndrome is also known as Oarsman’s Wrist, Crossover Syndrome, Squeaker’s Wrist, Peritendinitis Crepitans and APL Syndrome.
Intersection syndrome is typically caused by repetitive wrist movements, especially those involving frequent extension and flexion of the wrist and thumb. While anyone can develop intersection syndrome, certain activities and professions make some people more susceptible.
Common causes of Intersection Syndrome include:
The most common symptoms of intersection syndrome include:
Intersection syndrome symptoms usually come on gradually but can sometimes appear after a single bout of intense activity.
A healthcare professional can usually diagnose intersection syndrome based on a physical examination and a review of your symptoms.
The location of the pain, swelling, and crepitus are key diagnostic indicators. However, in some cases, additional tests might be needed to rule out other conditions like De Quervain’s tenosynovitis or other types of wrist tendonitis.
Diagnostic tests for intersection syndrome may include:
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Intersection syndrome can usually be treated with conservative methods, meaning surgery is rarely needed. Common intersection syndrome treatment options include:
The first and most crucial step in intersection syndrome treatment is to stop the activity that’s causing the inflammation. Resting the wrist and forearm allows the tendons time to heal and reduces further irritation.
If rest is not an option due to work or other obligations, modifying the way you perform certain tasks can help. For example, changing your wrist position while typing or adjusting your grip when lifting objects can reduce strain on the tendons.
Applying an ice pack to the affected area for 15-20 minutes several times a day can help reduce inflammation. The cold constricts blood vessels, reducing the flow of inflammatory fluids into the tissues, while also numbing the area to provide temporary pain relief.
Be sure to wrap the ice in a cloth, or use a specially designed ice bag to avoid skin damage.
Over-the-counter nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen/Advil can help reduce both pain and inflammation. In some cases, your doctor may prescribe a stronger medication if necessary.
Wearing a splint or intersection syndrome brace to immobilize the wrist and support the thumb can help prevent further irritation of the tendons.
Wrist splints are especially helpful during the early stages of treatment or when resting isn’t enough to relieve symptoms, and can be helpful when returning to sports.
A physical therapist can design a specific intersection syndrome exercise program to strengthen the muscles around the wrist, improve flexibility, and prevent recurrence.
Electrotherapy such as ultrasound or shockwave therapy may also be used to promote circulation and reduce inflammation which can help to speed up the healing process.
In some cases, manual therapy techniques such as soft tissue mobilization or massage may be used to reduce stiffness and promote healing in the tendons.
Exercises are a really important part of intersection syndrome treatment and prevention and typically include:
In more severe or persistent cases, a corticosteroid injection may be used to reduce inflammation in the tendons and provide pain relief. This treatment is typically considered when other conservative methods haven’t worked.
There are potential risks with corticosteroid injections, including weakening of the tendon tissue, so they are usually not the first line of treatment for intersection syndrome and are used sparingly.
PRP therapy is an emerging treatment for intersection syndrome that uses your own blood to promote healing. A sample of your blood is drawn and then processed to concentrate the platelets. The platelet rich plasma is then injected into the affected tendons, where it promotes healing by stimulating cell growth and repair.
Surgery is usually a last resort and is rarely needed for intersection syndrome treatment. However, in chronic or severe cases, a surgical procedure may be performed to release the pressure on the tendons and remove any thickened or inflamed tissue. This helps to reduce friction at the intersection point.
Recovery from intersection syndrome surgery typically involves a rehabilitation program with physical therapy.
Prevention is always better than cure. Once intersection syndrome has been treated, taking steps to prevent it from recurring is essential, especially if the activities or sports that caused it are part of your daily life. The best ways to prevent intersection syndrome are:
Here you will find answers to the most frequently asked questions about Intersection Syndrome.
What Is Intersection Syndrome?
Intersection syndrome is a painful condition caused by inflammation and irritation of the tendons in the forearm, typically due to repetitive wrist and thumb movements. It is an inflammatory tenosynovitis at the intersection of the 1st extensor compartment (APL, EPB) and the 2nd extensor compartment (ECRL, ECRB) of the wrist.
What Are The Classic Signs Of Intersection Syndrome?
The most common symptoms of intersection syndrome are pain in the back of the forearm, approximately 4-6cm above the wrist towards the outer (thumb) side, and crepitus, a grating or creaking sensation during wrist or thumb movement
How Do You Treat Intersection Syndrome?
Intersection syndrome is treated with rest, ice, anti-inflammatory medications, and activity modification, often supplemented by physical therapy to strengthen and stretch the affected tendons. In more severe cases, corticosteroid injections or intersection syndrome surgery may be required.
How Long Does It Take To Recover?
Recovery from intersection syndrome typically takes a few weeks to a few months, depending on the severity of the condition and how well treatment and rest are followed. Most cases improve with conservative treatment within 4 to 6 weeks, but chronic or severe cases may take longer.
Intersection Syndrome Vs De Quervain's
Intersection syndrome is often misdiagnosed as De Quervain’s syndrome. While they are both overuse injuries that affect the wrist and thumb, there are some key differences. Intersection syndrome causes pain 4-6 cm above the wrist on the forearm whereas De Quervain’s causes pain at the base of the thumb and wrist.
Intersection syndrome is caused by repetitive wrist and thumb flexion and extension movements whereas De Quervain’s is caused by repetitive thumb movements and gripping activities.
Crepitus just above the wrist is a classic feature of intersection syndrome causing clicking or grating sensations with wrist movements, but rarely occurs with De Quervain’s. Finkelstein’s test will be positive with De Quervain’s but not with intersection syndrome
What Are The Extensor Compartments Of The Wrist?
There are a number of tendons that pass across the back (dorsal aspect) of the wrist. These tendons connect the forearm muscles to the hand bones and help to control wrist and hand movements.
Each tendon passes through one of six tunnels, known as the “extensor compartments”. Intersection syndrome occurs at the junction of 2 of these compartments.
The extensor compartments, from the radial (thumb) side to ulnar (pinky) side of the wrist, are made up of:
Compartment 1: Abductor pollicis longus tendon (APL) and extensor pollicis brevis tendon (EPB)
Compartment 2: extensor carpi radialis longus tendon (ECRL) and extensor carpi radialis brevis tendon (ECRB)
Compartment 3: extensor pollicis longus tendon (EPL)
Compartment 4: extensor indices tendon (EI) and extensor digitorum tendon (ED)
Compartment 5: extensor digiti minimi tendon (EDM)
Compartment 6: extensor carpi ulnaris tendon (ECU)
Intersection syndrome is just one possible cause of wrist and forearm pain.
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Page Last Updated: September 17th, 2024
Next Review Due: September 17th, 2026