Dorsal view left hand

Volar view left hand

The flexor tendon of the hand is responsible for finger flexion. The tendon runs through a tunnel called a tendon sheath in the palm and fingers that allow smooth gliding of the tendon as it flexes and extends. Along the flexor tendon there is a pulley system that maintains the tendon position and keeps it close to the underlying bones.

The A1 pulley may become inflamed and/or thickened thereby restricting smooth gliding of the tendon. Over time the tendon may also become inflamed and develop a small nodule on its surface and when this nodule passes  through the A1 pulley a sensation of catching is experienced. The obstruction may worsen over time and the finger may be locked and require straightening with help from the other hand.

Injury Mechanism:

• Repetitive flexion and extension with tenosynovitis/pulley inflammation and thickening

Causes:

• Repetitive finger movements
• Rheumatoid arthritis

Risk factors:

• Diabetes

Presentation:

• Pain over the palmar aspect of A1 pulley
• Catching sensation
• Deformity with locking of finger in flexion

Clinically:

• Tenderness at A1 pulley
• Pain with bending and straightening the finger
• Palpable mass
• Palpable click
• Locking of finger

Radiology:

• Radiological investigations usually not required

Non operative

• Rest
• Night splint keeping finger in extension
• Stretching exercises of the digit
• NSAIDS
• Topical local anaesthetic and steroid injection (LASI)

Surgery

Indications:

• Failed conservative treatment
• Catching with locking of finger

Surgical fixation options:

• Release A1 pulley (”tenolysis”): open or percutaneous release

LASI for trigger finger

Incision: over pulley

Release A1 pulley sheath

Active wrist ROM after 2 weeks

Finger adduction strengthening

Finger abduction strengthening

Hand grip strengthening