Tendovaginitis stenosans (swimming finger)

Anatomy: tendons, tendon sheath and A1 annular ligament

To bend the fingers, strong flexor tendons run from the forearm muscles through tendon sheaths into the fingers. Several ring and cruciate ligaments hold the tendons close to the bone. A particularly important structure is the A1 annular ligament in the palm of the hand at the level of the metacarpophalangeal joint (MCP).

• Flexor tendons: flexor digitorum profundus/superficialis for fingers, flexor pollicis longus for thumb
• Tendon sheath: slippery sheath, produces lubricating fluid
• Ring ligaments (A1–A5): “Guide rings” prevent the tendon from lifting off when bent
• A1 ring ligament: a common constriction when the finger snaps

If the tendon thickens or the tendon sheath narrows, the tendon brushes against the A1 annular ligament and temporarily gets stuck - the characteristic “snapping”.

What is tendovaginitis stenosas?

Tendovaginitis stenosas is a constriction disease of the flexor tendons in the area of ​​the A1 annular ligament. Micro-inflammatory changes and repeated irritation lead to tendon thickening (knot formation) or to cicatricial narrowing of the tendon sheath. When bent, the thickened tendon slides under the A1 annular ligament and can get stuck when stretched. The release causes the typical snapping sound and feeling.

• Commonly affected: middle and ring fingers, thumb (“trigger thumb”)
• Occurs unilaterally or multiple times, occasionally bilaterally
• Course from stress-dependent irritation to painful blockage

Typical complaints

• Snapping into place when bending or stretching (“triggering”)
• Pressure pain in the palm of the hand above the metacarpophalangeal joint
• Morning stiffness, starting pain, sometimes swelling
• Palpable knot in the flexor tendon
• Blockages up to the finger being firmly locked in a flexed or extended position
• Pain when gripping, carrying, working with tools or on the computer

Causes and risk factors

There is usually an interaction between mechanical overload and individual tissue susceptibility. Often no single trauma can be found.

• Repetitive gripping and strength work, crafts, vibration tools
• Long typing/scrolling, musical activities (e.g. string instruments)
• Systemic diseases: diabetes mellitus, rheumatoid arthritis, gout, hypothyroidism
• Hormonal factors: postpartum, menopause
• Anatomical tightness/thickened tendon, accompanying tendonitis
• In children, the thumb (trigger thumb) is more common, often without an apparent cause

Diagnostics in our Hamburg practice

The diagnosis is primarily made clinically. A careful examination clarifies the extent, finger involvement and differential diagnoses.

Ultrasound is also helpful in placing injections precisely and in a way that is gentle on the tissue.

Conservative treatment: exhaust first

Most cases can initially be treated without surgery. We combine education, activity modification, splinting, physical therapy and, if necessary, targeted injection. The aim is to relieve pain, calm inflammation and restore the lubricating tendon system.

• Activity modification: temporarily reduce grip and force, use ergonomic aids
• Splint/night splint: Immobilization of the metacarpophalangeal joint (MCP) in slight extension for 2–6 weeks
• Physio/occupational therapy: tendon gliding exercises, gentle stretching, transverse friction, ergonomic advice
• Anti-inflammatory: local cooling for acute irritation, heat for muscle tension; If necessary, NSAIDs for a short time
• Ultrasound-guided injection (corticosteroid + local anesthetic) to the A1 annular ligament: may reduce tightness and inflammation

For injection: Studies often show rapid relief, especially when it occurs for the first time and the symptoms last for a short time. Possible side effects include temporary increases in blood sugar (in diabetes), skin atrophy/depigmentation, tendon irritation, rarely infection or tendon rupture. We discuss the benefits and risks individually.

Other injections (e.g. PRP/hyaluronic acid) are discussed, but evidence is limited. We only use such procedures after careful indications and information.

Minimally invasive and surgical options – when do they make sense?

If, despite consistent conservative measures, relevant pain, frequent snapping or blockages persist for several weeks to a few months - especially with functional restrictions in everyday life or at work - an annular ligament split should be considered.

• Percutaneous A1 annular ligament splitting (often ultrasound-guided): small puncture, splitting the A1 annular ligament using a cannula
• Open A1 release: small incision in the palm of the hand for direct exposure and splitting of the A1 annular ligament

The procedure is usually possible on an outpatient basis under local anesthesia. The aim is to give the tendon enough space to glide again. Follow-up treatment: early functional mobilization, plaster/seam care, scar massage, occupational therapy if necessary.

• Possible complications: bruising, impaired wound healing/infection, injury to sensitive finger nerves, persistent pain/stiffness, rarely CRPS
• Ability to work and play sports: office work often after a few days, manual tasks after 2-3 weeks depending on the strain
• Prognosis: high satisfaction rates in studies – individual results vary

Course and prognosis

If detected early, the snapping finger often responds well to rest, splints and injections. The longer the blockages persist, the higher the risk of ongoing irritation and secondary joint or tendon stiffness.

• Spontaneous progressions are possible, especially with mild symptoms and consistent relief
• Diabetes and rheumatic diseases are associated with an increased risk of recurrence
• After annular ligament splitting, studies predominantly show a lasting improvement in symptoms; Recurrences are rare but possible

Self-help, ergonomics and simple exercises

• Control stress: limit strong grasping/tweezing movements, plan breaks
• Ergonomics: larger grip strengths, padded handles, vertical mouse, soft keyboard strokes
• Warmth/cold: if there is acute swelling, cool it down; if the muscles are tense, warm it moderately
• Try night splints for 2-6 weeks – especially if you have morning snapping
• Control blood sugar well (if you have diabetes), avoid stress that promotes inflammation

Exercises should not be painful. If symptoms or signs of inflammation increase, please reduce stress and consult a doctor.

When should you seek medical advice?

• Repetitive snapping or locking of a finger/thumb
• Pain and swelling in the palm of the hand for more than 2-3 weeks
• Redness, warmth, fever or rapid deterioration (suspected infection – emergency)
• Newly occurring sensory disturbances or loss of strength
• Children with a fixedly flexed thumb or a palpable lump

Differential diagnoses

• De Quervain tendovaginitis (tendon compartment 1, thumb side of the wrist)
• Intersection syndrome (crossing of the extensor tendons in the forearm)
• Ganglion/cyst of the flexor tendon or palm
• Dupuytren contracture (stringing of the palmar fascia)
• Osteoarthritis of the metatarsophalangeal or middle joints of the fingers
• Carpal tunnel syndrome (especially nighttime discomfort)
• Tendon rupture after injury
• Infectious tenosynovitis, gout, psoriatic arthritis

Special case: trigger thumb in children

In children, the thumb is usually affected. Parents notice a thumb that remains in a flexed position or a small lump on the flexor tendon. Often there is no pain. It is often sufficient to wait and do gentle stretching exercises at first; If persistence occurs, an operational solution can be considered. The decision is made individually after examination and information.

Your route to treatment in Hamburg

We take time for diagnosis and advice. First, a detailed clinical examination is carried out and, if necessary, an ultrasound. We discuss conservative options and – if appropriate – install a splint. We use ultrasound-assisted injection specifically and after informed consent. Only if conservative treatment is not sufficient will we explain to you the options for minimally invasive or open annular ligament splitting, including follow-up treatment.

You can find us at Dorotheenstraße 48, 22301 Hamburg. You can easily request appointments online via Doctolib or by email.