Trigger Finger

Fri, 08 May 2026 00:00:00 +0000

Also known as Stenosing tenosynovitis
A flexor tendon becomes trapped by thickening at the entrance to its sheath
Forced extension -> tendon passes the constriction by snapping/triggering
Secondary nodule can develop on the tendon
Unknown etiology, more common in diabetic patients
Rheumatoid arthritis -> synovial thickening, intra-tendinous nodules -> triggering
Thumb, ring and middle fingers are most commonly affected

Anatomy

Inability to extend the flexed digit and/or flex the extended digit
Patient notices click during flexion. While extending, the finger remains bent at the PIP joint -> with further effort it suddenly extends with a snap
Patient may notice a tender lump/knot/nodule in the palm in front of the MCP joint. It may be
- Thickened area in the pulley
- Nodular/fusiform swelling of the flexor tendon e.g. by healing of a partially lacerated tendon. The tendon nodule is usually proximal to the pulley, it may be distal in patients with rheumatoid arthritis
Triggering after surgical release may occur due to catching of the tendon in the palmar aponeurosis. This resolves over time.

Stretching, night splinting, combination of heat and ice
Corticosteroid injection at the mouth of the sheath
Recurrence within 6 months occurs in 30% cases, especially younger and diabetic ones. A second injection may be given.
Refractory cases need surgery
- Release of the pulley
  Thumb -> only A1, other fingers -> A1 + A0 (PA)
  Care should be taken to avoid injury to the digital neurovascular bundles, risk is greatest in the thumb (nerves are close to midline) and the index (radial digital nerve crosses the tendon)
- Flexor synovectomy with excision of one slip of flexor digitorum superficialis (in rheumatoid arthritis patient)
In babies, wait until 3 years of age. If no spontaneous recovery -> A1 pulley release