Intersection syndrome is an overuse inflammatory condition of the dorsal forearm, occurring where the tendons of the first dorsal compartment—the abductor pollicis longus (APL) and extensor pollicis brevis (EPB)—cross those of the second dorsal compartment—the extensor carpi radialis longus (ECRL) and extensor carpi radialis brevis (ECRB). This tendon intersection is typically located about 4–6 cm proximal to the wrist joint. Repetitive friction at this anatomical point causes tenosynovitis, characterized by localized pain and swelling.
Pain Location: Dorsoradial forearm pain, 4–6 cm proximal to the wrist joint.
Swelling: Visible inflammation at the intersection of affected tendons.
Crepitus: Audible or palpable “creaking” or “squeaking” sensation during wrist and thumb movements.
Tenderness: Pain upon direct palpation over the tendon intersection point.
Pain with Resisted Wrist Extension: Discomfort increases with resisted extension of the wrist.
Pain with Resisted Thumb Extension: Pain intensifies with thumb extension resistance, implicating APL and EPB tendons.
Decreased Grip Strength: Reduction in grip strength due to pain.
Warmth: Increased warmth over the inflamed area due to underlying inflammatory response.
Erythema: Occasional visible redness over the inflamed area.
Pain with Thumb Movements: Intensified pain with thumb movements, particularly forceful abduction or extension.
Distinguishing Intersection syndrome from similar conditions is essential:
De Quervain’s Tenosynovitis: Pain more distally, at radial styloid; involves only first dorsal compartment tendons (APL, EPB).
Wartenberg’s Syndrome: Superficial radial nerve entrapment causing pain and paresthesia without crepitus.
Extensor Carpi Radialis Tenosynovitis: Involves only second dorsal compartment (ECRL, ECRB), without first dorsal compartment involvement.
Thumb CMC Arthritis: Typically has joint stiffness, deformity, and pain localized at the thumb base joint.
Diagnosis is primarily clinical, supported by imaging:
Ultrasonography: Dynamic visualization of inflammation, tendon thickening, and fluid accumulation.
Magnetic Resonance Imaging (MRI): Detailed soft-tissue imaging revealing edema and tenosynovitis; reserved for complex or uncertain cases.
Management strategy targets inflammation reduction, pain relief, and recurrence prevention:
Rest and Activity Modification: Cease or modify repetitive wrist/thumb movements exacerbating symptoms.
Splinting: Immobilization of wrist/thumb with a neutral splint or thumb-spica splint.
Nonsteroidal Anti-inflammatory Drugs (NSAIDs): Ibuprofen or naproxen to reduce inflammation and pain.
Ice Therapy: Ice application during acute inflammatory phases to control swelling and discomfort.
Physical Therapy: Exercises focusing on stretching, strengthening, and therapeutic taping for long-term function and recurrence prevention.
Corticosteroid Injections: Injection into tendon sheath when conservative management fails; use cautiously to avoid tendon weakening.
Surgery: Rarely indicated, surgical decompression considered only after persistent symptoms despite comprehensive conservative measures.
Intersection syndrome requires accurate clinical differentiation from similar conditions and is best managed through conservative measures including rest, splinting, NSAIDs, and physical therapy. Advanced imaging confirms diagnosis in ambiguous cases. Corticosteroid injections and surgical intervention remain reserved for refractory cases. Early recognition, appropriate treatment, and preventive strategies ensure optimal patient outcomes.