Introduction

• Type of repetitive strain injury (RSI) (neuromusculoskeletal injury that may be caused by repetitive tasks, forceful exertions, vibrations, mechanical compression, or sustained or awkward positions)
• Thickening of the extensor retinaculum resulting in tendon entrapment affecting
  • Predominantly impacts the abductor pollicis longus (APL) and extensor pollicis brevis (EPB) tendons, which pass through the 1st dorsal compartment of the wrist.

History

De Quervain tenosynovitis is named after the Swiss surgeon, Fritz de Quervain, who first described it in 1895.

Finkelstein’s test was described by Harry Finkelstein (1865–1939), an American surgeon, in 1930. A similar test was previously described by Eichhoff, in which the thumb is placed in the palm of the hand and held with the fingers, and the hand is then ulnar deviated (see images), causing intense pain over the radial styloid which disappears if the thumb is released. This test produces more false positive results than the test described by Finkelstein.

Aetiology

Repetitive and continued strain of the APL and EPB tendons as they pass under a thickened and swollen extensor retinaculum.

Risk factors:

• Sex (♀>♂)
• Certain repetitive movements
• Pregnancy
• Trauma
• Rheumatic diseases

Clinical presentation

• Pain and inflammation (in the region of the radial styloid)
  • Exacerbated by:
    • Motion and activity requiring ulnar deviation with a clenched fist
    • Thumb metacarpophalangeal (MP) joint flexion
  • eg. Wringing a washcloth, gripping a golf club, lifting a child, or hammering a nail

Physical examination:

• Swelling and tenderness in the region of the first dorsal compartment.

• Special diagnostic tests:
  • Due to a restricted gliding of the APL and EPB tendons in the narrowed compartment caused by a thickening of the extensor retinaculum and the APL and EPB tendons
  • Finklestein’s test
  • Eichhoff’s test

Differential diagnosis:

• CMC (carpometacarpal) joint arthritis
• Intersection syndrome (pain more towards the middle of the back of the forearm and about 2–3 inches below wrist)
• Cheiralgia paraesthetica (Wartenberg’s syndrome) (neuropathy of the hand generally caused by compression or trauma to the superficial branch of the radial nerve)

Management

From the original description of the illness in 1895 until the first description of corticosteroid injection by Jarrod Ismond in 1955, it appears that the only treatment offered was surgery. Since approximately 1972, the prevailing opinion has been that of McKenzie (1972) who suggested that corticosteroid injection was the first line of treatment and surgery should be reserved for unsuccessful injections.

NSAIDs:

• Anti-inflammatory & analgesia

Corticosteroid injection:

Performed into the tendon sheath about 1 cm proximal to the radial styloid where the tendons are palpable in the 1st dorsal compartment.

• Provide near complete relief with 1-2 injections
• Poor response due to:
  • Poor technique
  • EPB tendon lying in a separate compartment

Thumb spica splint:

Assist with pain management by immobilizing the thumb and wrist joints, thereby preventing thumb MP joint flexion and wrist ulnar deviation

Occupational therapy (OT): Adaptive equipment or modified techniques:

For activity performance is encouraged to allow for neutral wrist positioning during activities, such as repetitive typing and lifting, which place the wrist in ulnar deviation with the thumb MP joint in flexion

• Ergonomic keyboards, key holders, and modifications to tools allowing for neutral wrist positioning, etc.

Dequervain’s release surgery

Indicated if symptoms fail to improve or recur after 2 corticosteroid injections; it is usually performed in the outpatient setting

• Complications:
  • Injury to the superficial radial nerve
  • Entrapment of the abductor pollicis longus and extensor pollicis brevis
  • Subluxation of the tendons