The most common cause of the symptoms described is trigger finger. Trigger finger is a condition where the tendons controlling flexion of the digit become inflamed and swollen. As these tendons glide in and out within a fitting tunnel called a tendon sheath, any increase in girth of these tendons can disrupt the smooth gliding action. Trigger finger is categorized into 4 grades.
Grade 1 trigger finger:
Initially, the additional friction from the swelling of the tendons cause pain when moving the finger. This swelling is usually worse upon waking up in the morning as the swelling accumulates overnight. There is no demonstrable triggering or locking of the finger at this stage.
Grade 2 trigger finger:
As the condition progresses, the finger may start locking or getting stuck in flexion. This may be even more painful as the swollen tendon "clicks" in and out of the opening of the tight sheath.
Grade 3 trigger finger:
3A -
At this stage, the finger becomes locked when in a flexed position and can only be released with some force, usually by pulling it open with the other hand.
3B -
As the tendon swelling worsens, the finger can no longer be flexed fully as the tendon refuses to glide within its sheath. At this stage, the finger actually no longer locks, but the range of motion is significantly reduced and painful.
Grade 4 trigger finger:
This is the end stage of trigger finger where the finger is contractured, or stuck, in a flexed position. The finger looks bent and has minimal range of motion. The bent finger can no longer be straightened and this is called a fixed flexion deformity. At this stage, treatment is usually unsatisfactory as the proximal interphalageal joint (PIPJ) becomes stiff and non-pliable.
Treatment for trigger finger ranges from:
- simple splinting to rest,
- immobilize the inflamed tendon,
- taking non-steroidal anti-inflammatory drugs (NSAIDs),
- more invasive treatment such as corticosteroid injections and
- surgery.
A hand & wrist specialist will be able to advise on the appropriate form of treatment based on the grade of trigger finger one has.
