Intersection Syndrome

What is Intersection Syndrome?

Pain in wrist and forearm due to the activity which causes strain in the hand due to excessive movement is termed as Intersection syndrome¹.

Depending upon the anatomical position for betterment of understanding Intersection syndrome can be described as:

• Forearm intersection syndrome
• Wrist intersection syndrome

Forearm intersection or Crossover syndrome

Forearm intersection syndrome first described by Velpeau in 1841 and explained that inflammation and pain develop at the  intersection of the foremost and subsequent sections of dorsal extensor tendon due to overuse. Further in 1978, Dobyns et al. gave the name of this syndrome as ‘intersection syndrome. Alternatively, forearm intersection syndrome is also known as crossover syndrome².

Wrist intersection syndrome

This is less commonly reported condition comparing with forearm intersection syndrome. There is no risk of infection in the wrist intersection syndrome. The multiple tendons present in the wrist, such as EPL (extensor pollicis longus), ECRB (extensor carpi radialis brevis) and ECRL (extensor carpi radialis longus) tendons are mainly affected due to overuse or resultant of a traumatic event. The affected individual often complains pain and swelling in the wrist².

Causes

The two major clinical conditions involve in intersection syndrome are De Quervain Tenosynovitis and thumb carpometacarpal (CMC) arthritis³.

De Quervain Tenosynovitis

The first dorsal tendon in the wrist get affected and due to tendinitis pain arises during thumb motion.

Thumb carpometacarpal (CMC) arthritis

The articulation between the foremost metacarpal thumb bone and the trapezium carpal bone is termed as carpometacarpal (CMC). Arthritis causes laxity of the CMC joint and gradually leads to cartilage loss. These factors cause friction between the bones during movement and pain and swelling arise in the wrist joint³.

The intersection syndrome more frequently develops in weightlifters, racket sports players, rowers, horseback riders and skiers⁴.

Symptoms

The typical symptom of intersection syndrome is a pain at the site. But along with pain following detail symptoms arise¹:

• Pain due to friction between the bones
• The covering of the tendons become inflamed
• Pain occurs due to cartilage damage and friction develops during movement
• The movement becomes restricted
• Squeaking sound or feeling of creaking may experience by the affected individual due to rubbing between the tendons and the muscles. Clinically this condition is termed as Crepitus.
• At the site of the intersection, inflammation and redness can also found.
• Usually, the pain sensation does not stick to the intersection point, but it gradually spread up in the periphery of the forearm or downwards to the thumb.

Diagnosis

The symptoms of intersection syndrome, specifically radial forearm pain are not definite and similar with some other disorders including muscle strain, sprain in wrist ligament , inflammatory tenosynovitis, De Quervain’s tenosynovitis, a cyst in the ganglion, infection, Soft tissue neoplasm, Wartenberg’s syndrome, tendinitis in EPL and thumb CMC arthritis. Therefore, differential diagnosis is conducted to exclude the chance of development of such ailments.

The following diagnosis is important to judge the condition and diagnosed the severity of the disease.

A physical examination conducted in the orthopedic clinic can help to initial detection, which includes inflammation at the site of pain with generating of crepitus during active and passive movement of the wrist. Other than this, visible swelling, tenderness spread over the proximal wrist joint or the dorsal forearm etc also indicate the intersection syndrome.

Apart from physical examination following diagnostic tests are available to detect intersection syndrome.

• The Finkelstein’s test is conducted by creating passive stretching. Certain movements like an abduction in ulnar and thumb flexion cause uneasiness to the affected individual.
• Isometric muscle assessment of the abductor pollicis longus (APL), extensor pollicis brevis (EPB), extensor carpi radialis longus (ECRL), and extensor carpi radialis brevis (ECRB)
• Neurodynamic tests on upper limb

Confirmatory diagnosis

MRI provides a confirmatory result. In MRI, edema is diagnosed at the first and second extensor compartment tendons and that can proximally extend between abductor pollicis longus and extensor pollicis brevis , and the extensor carpi radialis longus and extensor carpi radialis brevis⁴.

Treatment

General measures

• The treatment and management of intersection syndrome always provide the advice that avoids the activities, which increase the intensity of the pain in the intersection syndrome. The restricted activities include actions which require tedious hand movements, such as wringing, heavy grasping or twisting and turning movements of the wrist.
• The wrist should not keep in bending position, but try to hold it in a straight position or maintain a neutral alignment with your arm¹.

Therapy to stimulate Blood flow

• Proper blood circulation is essential to reduce the pain. If intersection syndrome is resultant of injury, then proper rest of the site is vital to improving the blood circulation. Therefore, wearing of the wrap is better to plan to increase blood flow⁵.

Medications

Non-steroidal anti-inflammatory drugs (NSAIDs) like  ibuprofen, aspirin are available in the pharmacy store as an OTC product. These medications can help to reduce the pain in a temporary manner.

If the NSAIDs unable to control the pain, then the doctor can prescribe steroidal injection to control the inflammation and pain. Cortisone are first line choice for treating this condition.

Physiotherapy

The option for physiotherapy is also applicable for patients to get long term benefit. Physiotherapist also guides the patient some exercise tips, avoidance of the certain movement, positioning of the hand etc¹.

Surgical process

Surgical intervention rarely needful for intersection syndrome. In surgery, thick tendons around the site are removed. This surgery can be conducted under general anesthetic, local anesthetic or axillary block. After the successful anesthetic action swelled tensovium present in the tendon is removed by small incision over the site where the attached muscles are a crossover.

• After surgery, some precautions should follow for a quick recovery and also prevent infection¹.
• After surgery, the hand needs support to hold an elevated position from the heart.
• After 10 to 14 days, stitches were removed and during this period of time avoid wetting of the stitches.
• Dressing must not be removed before doctor order for it.
• The doctor may also recommend physiotherapy.

References

1. Intersection syndrome (2015) Available at: http://eorthopod.com/intersection-syndrome/ (Accessed: 17 October 2016).
2. Gael Jean Yonnet; Intersection Syndrome in a Handcyclist: Case Report and Literature Review; Top Spinal Cord Inj Rehabil. 2013 Summer; 19(3): 236–243. Published online 2013 Jul 27. doi: 10.1310/sci1903-236
3. David R Steinberg (2016); Intersection Syndrome; Online available; Retrieve from: http://emedicine.medscape.com/article/1242239-overview
4. Kaneko, S. and Takasaki, H. (2011) ‘Forearm pain, diagnosed as intersection syndrome, managed by taping: A case series’, Journal of Orthopaedic & Sports Physical Therapy, 41(7), pp. 514–519. doi: 10.2519/jospt.2011.3569.
5. BFST® devices are electrical medical appliances that actively stimulate blood flow in injured tissue(2011) Available at: http://kingbrand.com/intersection-syndrome-treatment.php (Accessed: 17 October 2016).