A plain-English, evidence-based guide for athletes, workers and clinicians
What is intersection syndrome?
Intersection syndrome is an over-use tenosynovitis that develops where the thumb tendons (first dorsal compartment: abductor pollicis longus + extensor pollicis brevis) cross the wrist-extensor tendons (second dorsal compartment: extensor carpi radialis longus + brevis) about 4–6 cm above the wrist. Repetitive friction triggers painful inflammation and thickening of the tendon sheaths.
Who gets it – and why?
- Sports: rowing, canoeing, skiing with deep pole plants, weight-lifting, racquet sports.
- Work: heavy raking, shovelling, repetitive screwdriver or wringing tasks.
- Mechanism: continuous wrist flexion–extension creates rubbing at the tendon ‘intersection’.
- Incidence: rare (<1 / 100 000 per year) but often missed or mis-labelled as de Quervain’s.
Typical symptoms
Feature | How it feels | Where to find it |
Dorsal-radial forearm pain | Aching or burning; worse with wrist extension & thumb lifting | ~5 cm above Lister’s tubercle |
Crepitus | A squeak or ‘sand-paper’ sensation on movement | Palpable / audible under light finger pressure |
Swelling ± redness | Localised cuff of puffy tissue | Same crossover point |
Weak grip | Pain-inhibition rather than true muscle loss | Jar lids, rowing stroke finish |
Clinical tip: Pain this far up the forearm with a palpable squeak is intersection syndrome until proven otherwise.
Diagnosis: clinical first, imaging second
- Provocation tests – resisted wrist extension or resisted thumb extension reproduces pain + crepitus.
- Differentiate from de Quervain’s – that hurts at the radial styloid (closer to the thumb base) and rarely squeaks.
- Imaging (only if doubt):
- Ultrasound – hypoechoic fluid and sheath thickening between the two compartments.
- MRI – STIR high-signal around both tendon groups; rules out other pathology.
Treatment pathway
5.1 First-line (almost always effective)
- Relative rest – stop or modify the provoking activity for 2–3 weeks.
- Splintage – 10- to 14-day wrist-neutral thumb-spica; removable for hygiene.
- NSAIDs – short course for pain / inflammation (check gastro-renal risks).
- Ice massage – 10 minutes, 3 × daily.
- Physio/hand-therapy (from week 2)
- Gentle wrist ROM → progressive eccentric strengthening.
- Technique check (rowing grip, pole plant, keyboard posture).
5.2 Second-line
- Ultrasound-guided corticosteroid + local anaesthetic into the ECRL/ECRB sheath if pain persists beyond 4–6 weeks. One injection is usually sufficient; avoid >2 to reduce tendon-rupture risk.
5.3 Surgery (rare < 5 %)
- Dorsal compartment release and synovectomy for truly recalcitrant cases.
- Day-case; splint 2 weeks → graduated rehab. Full return to sport in ~6–8 weeks.
6 Return-to-play guidelines
- Pain-free daily function.
- No crepitus during loaded wrist extension.
- Symmetric wrist-extensor strength on dynamometer testing.
Clinical Pearls / Key Points
- Pain 4–6 cm proximal to the wrist with a squeak = intersection syndrome, not de Quervain’s.
- Early splinting and activity change resolve > 90 % of cases.
- Ultrasound confirms diagnosis and guides steroid injection in stubborn presentations.
- Persistent cases may hide a partial tendon tear – consider MRI before returning to heavy sport.
Patient FAQs
Question | Straight answer |
Will I need surgery? | Very unlikely – fewer than 1 in 20 people need an operation once rest, splint and physio are tried. |
How long before I can row / lift again? | Most return pain-free at 4–6 weeks; start gently and build load over two further weeks. |
Is this the same as de Quervain’s? | No. That problem sits nearer the thumb base; intersection syndrome is higher up the forearm. |
Can I keep training if the pain is mild? | Light, pain-free activity is safe, but pushing through creaking pain delays healing. Listen to your body. |
Call to Action
If you have pain, book an appointment to be reviewed by Prof Imam or another member of our specialist team at The Arm Clinic. Early specialist care helps prevent long-term issues. Visit www.TheArmDoc.co.uk or book your consultation today. Phone: 020 3384 5588 | Email: Info@TheArmDoc.co.uk
Disclaimer
This information is for general educational purposes and should not be used as a substitute for professional medical advice. Consult a healthcare professional for individual guidance on your condition and treatment options.
This page was last clinically updated in May 2025