Treatment of Intersection Syndrome at the Master Knot of Henry
Begin with conservative management consisting of relative rest, activity modification, ice application (10 minutes through wet towel), and NSAIDs for short-term pain relief, with surgical release reserved for patients who fail 3-6 months of conservative therapy 1.
Initial Conservative Management (First-Line Treatment)
The treatment approach for tenosynovitis at the master knot of Henry follows established tendinopathy management principles, as most patients (approximately 80%) achieve full recovery within 3-6 months with conservative measures 1.
Core Conservative Interventions:
Relative rest: Reduce repetitive loading activities that stress the flexor hallucis longus (FHL) and flexor digitorum longus (FDL) tendons—particularly activities involving prolonged walking, running, or hyperextension of the great toe 2
Cryotherapy: Apply ice through a wet towel for 10-minute periods to reduce pain and swelling 1
NSAIDs: Use topical or systemic NSAIDs for acute pain relief, though they provide no long-term benefit and cannot be recommended over other analgesics 1. Topical formulations may reduce gastrointestinal side effects 1
Activity modification: Avoid activities that reproduce pain at the knot of Henry (located approximately one thumb-breadth lateral to the navicular tuberosity) 2
Important Caveat About Corticosteroid Injections:
Use corticosteroid injections with significant caution in this anatomical location. While locally injected corticosteroids may provide more effective acute pain relief than oral NSAIDs, they do not alter long-term outcomes and may reduce tendon tensile strength, predisposing to spontaneous rupture 1. The effects of peritendinous injections remain unknown, and intratendinous injection should be avoided 1.
Surgical Management (Second-Line Treatment)
If symptoms persist despite 3-6 months of well-managed conservative treatment, refer for surgical evaluation 1.
Surgical Options:
The evidence supports endoscopic release of the master knot of Henry as the preferred surgical approach over open procedures 3, 4, 5. Endoscopic techniques offer:
- Less surgical trauma and soft-tissue dissection (the knot of Henry is a deep structure requiring extensive dissection with open approaches) 3
- Potentially lower recurrence of fibrosis 3
- Earlier return to activity (as early as 6 weeks post-operatively) 5
Surgical Technique Components:
The procedure typically includes 2:
- Release of the knot of Henry
- Debridement and repair of any longitudinal splits in the FHL tendon
- Excision of interconnecting tendons between FHL and FDL
- Decompression of the FHL from the fibro-osseous tunnel entrance to the knot of Henry 5
Clinical Pearls and Diagnostic Considerations:
Diagnosis is based primarily on history and physical examination, as noninvasive imaging (ultrasound, MRI) may not reliably establish this diagnosis 2. However, MRI can identify marked fibrosis at the FHL-FDL interconnection and anatomical variations 6, 4, 7.
Key Clinical Features:
- Pain with prolonged walking/running
- Tenderness on palpation at the knot of Henry (one thumb-breadth lateral to navicular tuberosity)
- History of acute or chronic repetitive hyperextension of the hallux metatarsophalangeal joint 2
- Possible catching sensation of the great toe 5
Common Pitfall:
Do not confuse this with other foot tendinopathies. The specific anatomical location and mechanism (intersection of FHL and FDL tendons with resultant fibrosis) distinguish this condition 6, 4.