Physical Medicine and Rehabilitation for Trigger Finger Treatment & Management

Physical Therapy

Physical therapy is generally not required for patients with trigger finger. For chronic cases, however, treatment may include a trial of heating modalities followed by sustained nonballistic stretching of the flexor tendon, as well as soft-tissue mobilization of the A1 pulley. Following injection or surgery, a home exercise (stretching) program may be one component of treatment for patients. No therapy programs have been documented to improve trigger finger.

Occupational Therapy

If a trial of therapy is recommended for patients with chronic trigger finger or for individuals who require postsurgical hand therapy, the physician may refer them to a physical or occupational therapist, depending on his/her preference and the therapists' availability. The treatment provided by an occupational therapist is very similar to the above-discussed physical therapy treatment. In addition, the occupational therapist may provide a patient with strategies for completing activities of daily living with limited or no use of the affected hand while it is splinted or is recovering from surgery.

The main potential complications of trigger finger are pain and decreased functional use of the affected hand.

Potential complications of corticosteroid injection include the following:

• Infection - The use of sterile technique can minimize this problem.
• Bleeding - This can be minimized by applying direct pressure immediately after the procedure. Caution should be exercised before injecting a patient who is taking anticoagulants or an individual with a bleeding disorder.
• Weakening of the tendon - This increases the risk of subsequent tendon rupture, a possibility that is of particular concern if the injection is performed incorrectly (specifically, if the injection is administered into the tendon itself rather than just within the tendon sheath).^{[10, 11]} The risk may increase with multiple injections; however, at least some clinical researchers (eg, Anderson and Kaye) have found no episodes of tendon rupture after corticosteroid injection for this condition, even with repeated injections.^[12]
• Fat atrophy occurring locally at the injection site - Such atrophy can occur if the corticosteroid is injected into the subcutaneous tissue. This complication can cause a cosmetic depression in the skin, and tenderness can result from the loss of padding provided by the fat.
• Nerve infiltration and subsequent nerve injury - This complication is uncommon; it can be monitored by assessing sensation throughout the affected digit.

A congenital nodule on the flexor pollicis longus tendon generally does not respond to injections. Therefore, it usually requires referral for surgical intervention.

Trigger digits that fail to respond to 2 or perhaps 3 injections may require surgical treatment, including dissection of the nodule on the tendon and surgical release of the A1 pulley, under local anesthesia.

Surgical release is highly effective, leading to a permanent resolution of the triggering symptoms. Such surgery should be reserved for patients in whom conservative treatment methods fail.^[13]

When patients with diabetes were compared with persons who did not have diabetes, no statistically significant differences were found in surgical complication rates. This was also true when patients with type 1 diabetes were compared with individuals who had type 2 diabetes.^[13]

Surgical consultation for operative treatment may be required. Typically, such procedures are performed by an orthopedic hand surgeon or a plastic surgeon.

Corticosteroid injection in the area of tendon sheath thickening is considered to be the first-line treatment of choice for a trigger finger.^{[13, 14, 15, 16]}

Typically, such an injection is performed using a 25-gauge needle to inject a mixture of 0.5-1 mL of 40 mg/mL corticosteroid (eg, methylprednisolone) and 0.5 mL of 1% lidocaine (without epinephrine).

Corticosteroid injections seem to be less effective in treating trigger finger in patients with diabetes mellitus; thus, patients with diabetes are more likely to require surgical treatment.^[17]

A second corticosteroid injection may be performed 3-4 weeks after the first one. If 2 or perhaps 3 injections fail to provide adequate resolution, consider referring the patient for surgical release. Repetitive injections theoretically increase the likelihood of tendon rupture, although such a risk was not found in Anderson's study of repeated injections for trigger fingers.^[12]

Research in 2009 concluded that the most successful and cost-effective management strategy of trigger finger is the algorithm of 2 steroid injections prior to surgical intervention, if needed.^[18]

An increased risk of tendon rupture may potentially exist after corticosteroid injection, particularly if the corticosteroid is erroneously injected into the tendon itself rather than injected only into the tendon sheath.

Oral nonsteroidal anti-inflammatory drugs (NSAIDs) also may help.^[19]

Although corticosteroid injection has traditionally been administered into the tendon sheath (but not into the tendon itself),^[11] studies now seem to indicate that subcutaneous injection may be as effective as the intrasheath approach.^{[20, 21]} Additionally, in some cases, steroid injection into the subcutaneous tissue seems to result in better clinical outcomes than does injection into the sheath alone.^[20]

Custom-made splinting of the metacarpophalangeal (MCP) joint is another conservative treatment for those who do not wish to undergo a steroid injection or as an adjuvant to injection. Typically, a custom-made splint is used to hold the MCP joint of the involved finger at 10-15 º of flexion, leaving the proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints free. The average length of splinting is 6 weeks. In patients with symptoms longer than 6 months, splinting as a sole treatment strategy does not seem to eliminate the triggering events.^[9]

One study of thermoplastic splinting of the MCP joint flexion showed that improvement in stenosing tenosynovitis, numeric pain rating scale, number of triggering events, and overall perceived participant improvement in symptoms.^[22]