Trigger Finger

Welcome to Texas State University's Evidence-based Practice project space. This is a wiki created by and for the students in the Doctor of Physical Therapy program at Texas State University - San Marcos. Please do not edit unless you are involved in this project, but please come back in the near future to check out new information!!

Original and Lead Editors - Holly Pulket, Hilary Zachary, Angela Dempski, Dana Williams, Shannon Davis

Search Strategy

Databases: CINAHL, PUBMED, PeDro

Keywords: trigger finger, trigger thumb, stenosing tenosynovitis, flexor tenosynovitis, flexor tendon stenosis, A1 pulley AND tendonitis, A2 pulley AND tendonitis

Timeline: 9/15/2011 - 11/28/2011

Definition/Description

Each digit of the hand (excluding the thumb) has the ability to move freely throughout a full ROM into flexion and extension. The efficiency, fluidity, and forefulness of the movement is made possible by several "pulleys" along each digit. These pulley systems are comprised of a series of retinacular-type structures that are either annular or cruciform in nature. There are five annular pulleys (A1-A5) and three cruciform pulleys (C1-C3).

File:Finger pulleys.jpg

Trigger finger is a common condition that is thought to be caused by inflammation and subsequent narrowing of the A1 pulley of the affected digit. This inflammation can cause pain, clicking, catching, and loss of motion, especially into flexion. Commonly, trigger finger is referred to as "stenosing tenosynovitis". However, there have been histologic studies showing that the inflammation occurs more so in the tendon sheaths rather than the tendosynovium, making this name a false depiction of the pathophysiology.

Epidemiology/Etiology

As with most conditions, trigger finger can occur in anyone, but it is statistically shown that women in their fifth to sixth decade of life are more likely to develop the condition than men and nearly six times more frequently. Typically, the chance of developing trigger finger is 2-3%, but in the diabetic population, the percentage rises to 10%. The reason is not of glycemic nature, but rather is the actual cause of the duration and progression of the disease. Trigger finger can also concomitantly occur in patients with:

• carpal tunnel syndrome
• deQuervain's disease
• hypothyroidism
• rheumatoid arthritis
• renal disease
• amyloidosis

caused by a difference in diameters of a flexor tendon and its retinacular sheath due to thickening and narrowing of the sheath.

Characteristics/Clinical Presentation

Trigger finger can have a range of clinical presentations. (Makkouk et al). Initially the patient may present with painless clicking with movement of the digit. This can progress to painful catching or popping typically at the MCP or PIP joints, stiffness and swelling especially in the morning, loss of full flexion/extension, palpable painful nodule, and/or finger locked into a flexed position. (Makkouk)

Other symptoms are slight thickening at the base of the digit, pain that may radiate to the palm or to the end of the digit.(Harvard)

Differential Diagnosis

The main characteristic of trigger finger is a popping and/or catching with movement of the digit, especially in flexion to extension. However, this is not a unique characteristic to trigger finger. Other etiologies associated with a locking digit can include:

• Dupuytren's contracture (Schoffl et al)
• Focal dystonia
• Flexor tendon/sheath tumor
  
• Sesamoid bone anomalies
• Post-traumatic tendon entrapment on the metacarpal head
• Hysteria 

Complaints of pain at the MCP joint could be associated with any of the following:

• DeQuervain's (for trigger thumb only)
• Ulnar collateral ligament injury/Gamekeeper's thumb (Schoffl et al)
• MCP joint sprain
• Extensor apparatus injury
• MCP joint osteoarthritis (Schoffl et al)

 (Makkouk et al)

Diagnosis of trigger finger can be confirmed with the injection of lidocaine into the flexor sheath, which could relieve pain and allow flexion/extension of the joint.  Imaging is not typically indicated, but ultrasound and MRI may be used to rule out other etiologies (Makkouk et al).

Outcome Measures

NPRS, Open& Close Hand 10 Times, Stages of Stenosing Tenosynovitis, Participant Perceive Improvement in Symptoms, Grip Strength (Jamar dynameter),  DASH Outcome Measure

(need charts for Stages of Stenosing Tenosynovitis & Participant Perceive Improvement in Symptoms)

add links to outcome measures here (also see Outcome Measures Database)

Examination

Hx: Recent trauma to the area may be reported. Job related repetitive movements. A history of locking or snapping while flexing or extending the affecter finger or thumb. Patient might complain of a snapping sensation that causes pain that radiates to the palm or toward the end of the finger or thumb.
     PMH: Diabetic individuals have an almost 4-fold increased risk for developing trigger finger  and Rheumatoid Arthritis;  Associated with disorders that cause connective tissue changes such as RA, Gout, and Diabetes .

Observation: May present with a digit locked in flexion; boney proliferative changes could be seen in the subadjacent distal phalangeal joint

Palpation: Painful nodule in the palmar MCP area as a result of intratendinous swelling

ROM: Loss of motion should be seen in the affected finger with patient unable to fully extend finger.

MMT: Muscles involved are Flexor Digitorum Profundus and Flexor Digitorum Superficialis.  However, if the finger is locked in place, it becomes impossible to test. Grip strength may be measured utilizing the Jamar Dynameter.

Joint Accessory Mobilization: Secondary to the development of PIP contracture and digital stiffness, joint mobility of all the effected digits should be assessed, especially PIP joint . Most cases are secondary to thickening of the digits A-1 pulley but other pulley sights, the MCP joint or the carpal tunnel, can be involved. As a result a consideration of these areas and surrounding tissues is reasonable and should be considered in a complete assessment.  Wrist joint accessory mobilization can be beneficial for digit pathologies. .

Special Test: Open and Close hand 10x- Ask patient to actively make ten fists. The number of triggering events in ten active full fists was then scored out of 10. If participant’s finger remained locked at any time they were to stop and given a score of 10/10.

Medical Management

Individuals planning on undergoing medical management of trigger finger should attempt conservative treatment before considering the medical treatments listed below.

Corticosteroids

Corticosteroid use has been shown to be effective in reducing pain and the frequency of triggering. The shot is injected into the affected tendon and reduces the inflammation and pressure on the tendon for better gliding through the flexor pulleys. Ultimately, application, by a primary care provider, is an effective and safe alternative to surgical therapy. Patient satisfaction, safety, and functional improvement are characteristic of steroidal injections in comparison to surgical treatment. Open and percutaneous surgical division of the A1 pulley is associated with higher costs, longer absence from work, and the possibility of surgical complications. Studies have also shown the combination of corticosteroid injections with lidocane to have significantly more effectiveness than lidocane alone.
Side effects (may include):
Flaring at injection site, local infections, tendon ruptures, allergic reactions, and atrophy of subcutaneous fat tissue.
Contraindications:
Those under the age of 18, those with prior treatment or surgery to the area within the last six months, or possible traumatic or neoplastic origin of symptoms.

Video courtesy of the American Society for Surgery of the Hand

Open Surgical Technique:
This technique, considered to be the gold standard, is performed by making a longitudinal incision in the palmar crease over the metacarpophalangeal joint of the involved digit and followed by release of the flexor digitorum superficialis and profundus tendons. This procedure, which lasts 2-7 minutes, has a longer average time of discomfort (45 days) post op. An advantage to this technique is it allows the pulley to be visualized and there is less risk of damage to the digital nerves in comparison to endoscopic techniques.

Endoscopic Surgical Technique:
This technique is performed by making two incisions: one at the palmar crease over the metacarpophalangeal and the other at the volar crease of the finger. An endoscope is then introduced to cut the pulley to allow a release of the flexor tendons. This procedure, which lasts 2-9 minutes, has a shorter average time of discomfort (23 days). Other advantages are the absence of scars and scar related problems and a shorter post-op rehabilitation. However, there is a large learning curve and the instruments are costly for this procedure.

Percutaneous Release:
This technique can be performed with or without imaging. Non-image-guided (blind) percutaneous release is performed by using anatomical landmarks to avoid injury to the tendons and neurovascular structures. The recovery time is shorter than an open surgery but the potential for damage to digital nerves is more probable, especially to digits 1, 2, and 5 (thumb, index and little finger). A new technique using ultrasound-guidance helps clearly identify the tendons and neurovascular structures, preventing potential complications that are present with non-image-guided percutaneous release and compares favorably with surgical techniques as well.

Physical Therapy Management

The chronic nature of the symptoms associated with trigger finger makes conservative treatment difficult and often frustrating. Still conservative care is always recommended as a treatment plan prior to surgical intervention.

As with all disorders of the upper extremity, proximal segments including the shoulder, and neck must be screened. Also, posture should always been addressed and modified properly to provide the patient with the best possible care and outcomes as it can contribute to distal problems.

Patient Education

This is going to be the main component of treatment. Since trigger finger is observed as an overuse injury, educating the patient on the cause how to reduce use can help to relieve a lot of symptoms.

Education should be given on:

• Rest
• Modifications of activities such as those involving a grip or fist (5) by using specialized tools
• Splinting
• Icing/Heat
• Posture
• NSAIDs via the physician

Splinting: ENTER PICTURE!!!!

One of the first steps in treatment is to stop doing anything that aggravates the condition. 2 This can be done by the use of splints. Most authors agree that the intent of splinting is to alter the biomechanics of the flexor tendons while encouraging maximal differential tendon glide. However, authors disagree on which joints to include in the splint and the degree of joint positioning. 3 There are various ways to splint a patient and bottom line is it will depend on what provides the patient with the most relief. It should be noted, however, that splinting yields lower success rates in patients with severe triggering or longstanding duration of symptoms. 1
Multiple studies have been done about the effectiveness of splinting on reduction of pain and/or symptoms. Additionally studies have been used to try to find the best type of splinting. Almost all splinting in these studies was done for between 6-10 weeks.

Two major types of splinting have been the most recently studied:

1. Splinting at the DIP joint. This showed to have resolution in 50% of the patient’s symptoms. 1
2. Splinting at the MCP joint with 15 degrees of flexion. This showed to resolution of patient’s symptoms at both 65% and 92.9%, which is consistent with the current literature. 1,3

Other Options: 4, 5, 6

Modalities such as heat, ice, ultrasound, E-stimulation, and massage as well as stretching, joint motion (active and passive) can have some positive effects on trigger finger. It is thought that heat can help by providing increased blood flow and extensibility to the tendon. Following heat with stretching is thought to add effectiveness providing more extensibility with plastic deformation. Additionally the joint movement and mobilizations increase joint and soft tissue mobility via a slow, passive therapeutic traction and translational gliding. 5
Although the evidence is lacking there have been some documented cases and studies of improvement with various combinations of these techniques:

• 5) 74 patients were treated with ten sessions of wax therapy, ultrasound, stretching muscle exercises and massage yielded 68.8% resolution of symptoms and remained symptom free 6 months out.
  
• (6) 60 trigger thumbs in 48 children were treated daily with passive exercise of their affected thumb by their mother resulting in a cure rate of 80% for stage 2 and 25% for stage 3 thumbs after an average of 62 months.
  
• (4) Case Study: Both ART (Active release technique) and Graston techniques, followed by ice post-tx and self-mobilizations of the thenar eminence and 1st digit yielded no pain and only slight irritation at the joint capsule with mild weakness after 8 treatments. The patients were given thera-putty and released with exercises (flexion, extension, abduction, adduction) to continue STR. At the follow-up period of 14 months patients still reported complete resolution and pre-injury strength.
  

Key Research

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Resources

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Clinical Bottom Line

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Recent Related Research (from Pubmed)

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References

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