Intersection Syndrome

Intersection syndrome is an injury caused by overuse of two sets of tendons that cross over each other on the thumb side of the forearm. During repetitive wrist motions, the tendons that control the thumb and the tendons that extend the wrist constantly slide over each other. Over time, the friction that builds up at this intersection leads to pain and inflammation of the tendons, a condition called tenosynovitis. Importantly, intersection syndrome can be easily mistaken for other tendon disorders, including De Quervain’s tenosynovitis, which causes pain closer to the wrist.

Intersection syndrome is often thought of as a sports injury, since weightlifters, tennis players, skiers, and rowers (who call intersection syndrome “oarsman’s wrist”) are most likely to be diagnosed. However, anyone who uses repetitive wrist motion, especially when combined with a strong grip, may be at risk.

Intersection syndrome begins gradually, with symptoms worsening over time. Without intervention, wrist function will eventually be impaired.

Hallmark symptoms of intersection syndrome include:

• Pain on the top of the forearm, a few inches above the wrist on the thumb side, that worsens with use
• Tenderness, redness, or warmth over the crossing point of the tendons
• Crepitus, a sometimes-audible squeaking, creaking, or rubbing sensation when moving the wrist
• Wrist weakness and reduced grip strength

Symptoms often become more noticeable after repetitive activity and improve temporarily with rest.

To understand what causes intersection syndrome, it’s helpful to know a little bit about wrist anatomy. The tendons that control hand movement are bundled intosix individual compartments in the wrist, each of which is lined with a smooth, slippery covering called the synovial sheath. Under normal circumstances, the synovial sheath protects the enclosed tendons from rubbing directly against each other.

The firstand second extensor compartments house the tendons that control the thumb and the wrist, respectively. These compartments cross over each other, they intersect, at a spot on the dorsal (back) and radial (thumb) side of the wrist, usually around 1.5 to 2.5 inches behind the wrist. Repetitive overuse of the tendons causes friction at this intersection, and the protective synovial sheaths lose some of their ability to glide smoothly past each other. This causes the pain and inflammation associated with intersection syndrome.

People most at risk for developing intersection syndrome use frequent, repetitive wrist flexion and extension, bending the wrist up and down, combined with a forceful grip. As your thumb moves to control your grip and your wrist flexes up and down, the point of tendon intersection experiences friction. With repeated use and insufficient recovery time, the synovial sheaths are no longer able to protect the tendons, and you’ll experience pain and, eventually, loss of function.

Diagnosis begins with a thorough evaluation of your symptoms, medical history, occupation, hobbies, and athletic activities. Your physician will examine your forearm to pinpoint exactly where the pain is, and they will test your range of motion and grip strength. It’s important to be precise about where the pain is to differentiate between intersection syndrome and De Quervain’s tenosynovitis.

In many cases, a diagnosis can be made after a careful physical examination, but for cases that are less clear, diagnostic ultrasound or MRI may be recommended. These imaging techniques will help your doctor confirm the diagnosis while ruling out fractures, arthritis, torn tendons, or other wrist conditions.

In most cases, conservative treatment can bring substantial relief. Aconservative treatment plan may include:

• Temporary activity modification
• Splints or braces
• Ice and non-steroidal anti-inflammatory medications (as directed by your doctor)
• Physical therapy, including targeted stretching and ergonomic coaching

If these conservative treatments aren’t sufficient, your doctor may recommend a corticosteroid injection into the inflamed tendon sheath. While corticosteroids are extremely effective at controlling inflammation and pain, the results are temporary, and you risk further damage if you don’t address the underlying cause of your pain.

In rare cases,surgical release and debridement may be recommended. This minimally invasive technique involves making a small cut in the tendon sheath to alleviate pressure on the tendon and removing the inflamed parts of the synovial sheath.

While recovery time depends on the severity of your symptoms and the treatment you require, most people report substantial improvement within2-3 weeks of starting conservative treatment, and full recovery can be expected within several months. More advanced cases or cases that require surgery often require a structured rehabilitation period that includes physical or occupational therapy.

During your recovery, your care team will help you identify small modifications to your technique or the equipment you use that can help you avoid intersection syndrome in the future. They will work with you to create a treatment plan that gradually gets you back to the sport, work, and hobbies you enjoy.

You don’t have to live with ongoing wrist pain. Dr. Knight and the experts at The Hand and Wrist Institute have been providing compassionate orthopedic care to the Dallas-Fort Worth area for over 25 years. By combining our deep expertise with the latest technologies, we’re able to care for these injuries. Contact us today to schedule an appointment.

How can you test for intersection syndrome?

Because the tissue involved with intersection syndrome is all soft tissue, x-rays are not an effective imaging test to diagnose the condition, but soft-tissue imaging like MRI can be integral in determining a precise diagnosis, in addition to physical examination by the doctor to find out the exact level of pain you are suffering, as well as the affected area and any related systems that may have become affected as collateral damage from the syndrome.

Do injections help cure intersection syndrome?

One very common non-surgical treatment for intersection syndrome is the injection of corticosteroids into the affected area, but this is not a permanent cure. The effects of the injection will greatly relieve pain and discomfort but are temporary and are not a long-term solution to the condition, as the underlying problems will continue to develop while masked by the steroids, and if those are left untreated then the condition will continue to deteriorate until surgery becomes necessary.

What about other non-surgical treatments?

In some cases, the use of kinesiology tape on the affected limb can be an effective splinting technique to reduce the crepitus and discomfort caused by intersection syndrome. The tape acts in the same way as a splint or brace, but still allows you to engage in some daily activities that a larger and bulkier device might not. At home resting and icing is very important for early treatment of the condition. At least a week of constant resting of the tendons will help to stave off the development of full blown intersection syndrome.