Treatment of Flexor Tenosynovitis
For non-infectious flexor tenosynovitis in adults with repetitive strain, initiate conservative management with relative rest, thumb spica splinting (for radial-sided involvement), NSAIDs, and eccentric strengthening exercises, reserving surgery only for patients who fail 3-6 months of conservative therapy. 1, 2
Distinguish Infectious from Non-Infectious Tenosynovitis First
Critical first step: Determine if this is pyogenic (infectious) versus inflammatory/degenerative tenosynovitis, as management differs dramatically. 3
Red Flags for Pyogenic Flexor Tenosynovitis (PFT):
- Kanavel signs (fusiform swelling, flexed posture, pain with passive extension, tenderness along flexor sheath) 3, 4
- Acute presentation with rapid symptom onset 4
- Fever, systemic signs of infection 3
If pyogenic FTS is suspected: Immediate IV antibiotics and urgent surgical consultation for irrigation and debridement are required—this is a surgical emergency. 3, 4
For Early/Mild Presentations:
- Patients with shorter symptom duration and fewer Kanavel signs may be treated successfully with antibiotics alone without surgery 4
- Subacute presentations (longer symptom duration, fewer Kanavel signs) may represent inflammatory conditions rather than true pyogenic infection 4
Conservative Management for Non-Infectious Tenosynovitis
First-Line Treatment (0-6 weeks):
Relative rest and activity modification:
- Reduce repetitive loading activities that provoke symptoms 1, 2
- Avoid complete immobilization as this causes muscle atrophy 5
Splinting:
- Thumb spica splinting for radial-sided flexor involvement (FCR tenosynovitis) 6, 7
- Immobilize affected tendons while allowing some controlled movement 6
Cryotherapy:
- Apply melting ice water through wet towel for 10-minute periods repeatedly for acute pain relief 1, 2
NSAIDs:
- Topical NSAIDs are effective with fewer systemic side effects 2, 6
- Oral NSAIDs can be used for pain relief 1, 6
Second-Line Treatment (6-12 weeks):
Eccentric strengthening exercises:
- These are the cornerstone of treatment and may reverse degenerative tendon changes 2, 5
- Begin once acute inflammation subsides 1, 2
Physical therapy modalities:
- Deep transverse friction massage may reduce pain 2
- Therapeutic ultrasound may decrease pain and increase collagen synthesis, though evidence is weak 6, 5
Corticosteroid injection:
- Inject into tendon sheath, never into tendon substance itself 5
- More effective than oral NSAIDs for acute pain 5
- Limit to maximum 2-3 injections to avoid tendon weakening 6, 5
- Consider ultrasound guidance for accuracy 6, 5
Surgical Management
Indications for surgery:
- Failure of conservative therapy after 3-6 months of consistent treatment 2, 6, 5
- Approximately 80% of patients recover with conservative management alone, so surgery should be reserved for the 20% who fail 2, 6
Surgical options:
- Open or arthroscopic release of affected tendon sheath 8, 7
- Decompression of anatomical tunnels (trapezium canal for FCR, tarsal tunnel for FHL) 8, 7
Special Considerations
Evaluate for Underlying Systemic Disease:
- If multiple tendons are symptomatic simultaneously, evaluate for rheumatic disease (rheumatoid arthritis, systemic lupus erythematosus) 5, 9
- Flexor tenosynovitis can be the initial manifestation of SLE and may require systemic corticosteroids 9
Common Pitfalls to Avoid:
- Mislabeling as "tendinitis": Most chronic cases are degenerative ("tendinosis"), not inflammatory, which affects treatment approach 1, 2
- Injecting corticosteroids into tendon substance: Only inject into sheath to avoid tendon rupture 5
- Multiple corticosteroid injections: Weakens tendon structure despite short-term relief 5
- Premature surgery: Must complete adequate 3-6 month conservative trial first 2, 5
- Ignoring biomechanical factors: Failure to address technique problems or ergonomic issues leads to recurrence 2