April 11, 2024

Trigger finger occurs due to narrowing of the A1 pulley of flexor tendon sheath causing entrapment of the flexor tendon with restriction of flexion and extension movement

Most common in long and ring finger is most common in adults

Women older than 50 years of age

Generally associated with diabetics and inflammatory arthropathy

Etiology

Repetitive grasping activities

Types

  • Primary
  • Secondary
    • DM
    • Gout
    • RA
    • Amyloidosis
    • Storage Disorder

Involvement of dominant hand

Histologically

Fibrocartilagenous metaplasia of flexor tendon sheath

  • Nodular: localized swelling is a free mobile
  • Not well-defined and widespread

Classification of trigger finger

Green Classification

GradeDescription
IPain and tenderness of A1 pulley
IICatching of digits
IIILocking of digits; passively correctable
IVFixed, Locked digit
Green Classification

Quinnell’s Classification

GradeDescriptionPrognosis
INormal movement, no painExcellent
IINormal movement, occasional painGood
IIIUneven movementPoor
IVIntermittent locking, actively correctablePoor
VLocking, only passively correctablePoor
Quinnell’s Classification

Management Options

Splinting

Immobilized the joint and reduced the movement of the tendon within flexor sheath

Corticosteroids

Success rate: 60-92%

Most effective in primary trigger finger, single finger, nondiabetic

Can be used with/without Local anesthesia

  • Betamethasone
  • Dexamethasone
  • Triamcinolone

Rare complications

  • Tendon rupture
  • Fat necrosis
  • Skin necrosis
  • Injury to the digital nerve

Per-cutaneous release

Indicated in recurrence following repeated corticosteroid injection

A similar outcome to open surgery

After hyperextension of the MCP joint, the hypodermic needle is passed through the flexor tendon sheath incised proximally and distally

Open release

  • Failed conservative treatment
  • Digit cannot be fully extended at IP joint
  • A1 pulley is cut under direct visualization taking care not to damage A2 pulley
  • Followed by non-restricting bandages

In Rheumatoid arthritis:

The entire annular pulley system should be preserved to prevent further ulnar drift to the finger

They are treated with tenosynovectomy and excision of one slip of FDS

Trigger thumb

Trigger thumb
Trigger thumb

Trigger thumb is different from congenital trigger thump

Similar to trigger finger

Newer evidence has found a fourth pulley in 75% of cases, which may contribute to stenosis

Congenital trigger finger

Incidence: 3/1000

Etiology: Unknown

Often bilateral:

  • Congenital
  • Storage disorder
  • DM

Unlike in adults, the thumb does not trigger but remains in FFD of the IP joint (Development rather than congenital)

Pathological Nodular tendon thickening: Notta Node

Treatment Options

Observation initially

Generally doesn’t respond to conservative treatment

In some cases, spontaneous resolution occurs

Hence, the period of observation of 3 years ( Upper limit) before attempting surgical correction i.e. Annular pulley release to prevent IP joint contracture

In Pedriatic trigger finger

Generally caused by anatomical anomalies

Treatment depends upon cases

A1 Pulley release may not resolve to trigger, additional A3 release or resection of ulnar FDS slip may be required