Intersection Syndrome (Also known as crossover syndrome; Oarsman’s wrist)
Intersection syndrome is a chronic, overuse injury in the distal radial forearm where the tendons of the 1st extensor compartment and the 2nd extensor compartment cross over, resulting in bursitis or tenosynovitis of either or both tendon sheaths. This condition is easily confused with and misdiagnosed with de Quervain’s tenosynovitis!
Often found in rowers, weight lifters, and skiers. Prolonged activities that involve repetitive wrist extension and flexion increases the risk of this injury.
Figure 1 – Extensor Compartments of Wrist
(From Right to Left 1-6 – 1. Abductor Pollicis Longus (APL) and Extensor Pollicis Brevis (EPB) 2. Extensor Carpi Radialis Longus and Brevis (ECRL & ECRB) 3. Extensor Pollicis Longus (EPL) 4. Extensor Digitorum (ED) 5. Extensor Digiti Minimi (EDM) 6. Extensor Carpi Ulnaris (ECU)
Figure 2 – Anatomy of Intersection Syndrome
(image source http://iop.net.au/wp-content/uploads/2015/07/cotw_july3.jpg)
Figure 3 – Surface Anatomy of Intersection Syndrome
Figure 4 – Illustration of Intersection area of pain
Patient will often present with gradual development and worsening of pain in the distal radial forearm.
Pain is proximal to the wrist, within 4-8cm to Lister’s tubercle of the radius
Pain worsens with activities that involve repetitive forceful wrist flexion and extension
Pain is typically worse with movements of the wrist than movements of the thumb
Pain subsides with rest from such activities
Pain may be associated with localized swelling or crepitus (squeaking sensation) with active or resisted wrist or thumb extension (1)
Diagnosis of intersection syndrome is based on clinical findings
Imaging is often not required for diagnosis; however, imaging may help to confirm the diagnosis and/or to rule out other conditions
X-ray of the wrist and forearm: non-specific, to rule out other abnormalities not helpful in the diagnosis. Only indicated to rule out other pathology
Ultrasound of the forearm, esp. area of tenderness: may reveal tenosynovitis of tendon sheaths between the first two extensor compartments. An adventitial bursa between the two compartments at the level of intersection may also be seen (2)
MRI is indicated if there is persistent pain despite treatment or if the diagnosis is unclear after X-rays and ultrasound
If the initial treatment fails after 3-4 weeks, a referral to surgery is indicated surgery is very rarely indicated. Consider only after failed prolonged conservative management
Surgical options include:
release of the fascial sheaths of the tendons in the first dorsal compartment (doesn’t appear to be typically done)Postoperatively, the wrist is splinted for 7–10 days followed by a stretching and strengthening program, and return to sport is allowed when the patient is symptom free (3)
Author Dr. Hao Liu (July 24, 2017, PR KA)