eMedicine Specialties > Physical Medicine and Rehabilitation > Upper Limb Musculoskeletal Conditions
Trigger Finger
Updated: Apr 18, 2008
Introduction
Background
Trigger finger results from thickening of the flexor tendon within the distal aspect of the palm.1,2 This thickening causes abnormal gliding of the tendon within the tendon sheath. Specifically, the affected tendon is caught at the edge of the first annular (A1) pulley. Patients can have difficulty flexing the affected digit if the tendon is caught distal to the A1 pulley, or extending the digit, if the tendon is caught proximal to the pulley. The condition is very painful, especially when the locked digit snaps (releases) beyond the restriction by the use of increased force. Images 1-2 illustrate normal and thickened tendons, respectively.
See also the following related eMedicine topics:
Flexor Tendon Anatomy
Trigger Thumb
Trigger Finger [Orthopedic Surgery]
Pathophysiology
Normally, the tendons of the finger flexors glide back and forth under a restraining pulley.3,4,5 Thickening of the flexor tendon sheath restricts the normal gliding mechanism. A nodule may develop on the tendon, causing the tendon to get stuck at the proximal edge of the A1 pulley when the patient is attempting to extend the digit, thereby causing difficulty. When more forceful attempts are made to extend the digit, by using increased force from the finger extensors or by applying an external force (for example, by exerting force on the finger with the other hand), the digit classically snaps open with significant pain at the distal palm and into the proximal aspect of the affected digit. Less commonly, the nodule is restricted distal to the A1 pulley, resulting in difficulty flexing the digit.
Frequency
United States
Trigger finger is a relatively common condition.
Mortality/Morbidity
- Morbidity - Trigger digits can be a significant source of pain. In addition, the difficulty in achieving a normal range of motion at the digit can make functional tasks (eg, grasping objects, typing) problematic.
- Mortality - No mortality is known to be associated with this condition.
Race
No racial predisposition is known to be associated with trigger finger.
Sex
This condition has a higher incidence in women (75%) than in men.
Age
Trigger digits are most commonly seen in adults, with the average age range for its occurrence being 52-62 years.
Clinical
History
- A classic complaint is difficulty in achieving full extension of a single digit, which eventually releases or snaps open with pain at the distal palm and into the digit.
- In individuals with diabetes or rheumatoid arthritis, multiple digits may be involved in trigger finger.
- Some patients have difficulty with finger flexion rather than extension, although the former is less common.
- Other patients may have a painful nodule in the distal palm without any catching or triggering.
- Some patients report stiffness in the fingers, especially after they have been asleep or following other periods of inactivity.
- Some patients may have a history of repetitive trauma to the affected area.
- Patients may have a history of diabetes or rheumatoid arthritis.
- Some patients report swelling of the affected digit, particularly at the digit's base or proximal aspect.
See also the following related Medscape topics:
Resource Center Diabetic Microvascular Complications
Resource Center Incretin Hormones in Diabetes and Metabolism
Resource Center Rheumatoid Arthritis
CME Managing the Patient Throughout the Course of RA: Three Case Studies
Physical
- At the level of the distal palmar crease, a tender nodule can be palpated, usually overlying the metacarpophalangeal (MCP) joint.
- The affected digit may lock in a flexed or (less commonly) extended position. When the patient attempts to move the digit more forcefully beyond the restriction, the digit may snap or trigger beyond the restriction. The triggering movement is very painful for the patient.
- In severe cases, the patient is unable to move the digit beyond the restriction, so no triggering occurs.
- With a trigger thumb, the tenderness to palpation is found at the palmar aspect of the first MCP joints rather than over the distal palmar crease.
Causes
- Congenital cases of trigger thumb are generally caused by a nodule of the flexor pollicis longus tendon.
- In adults, some cases may be associated with repetitive trauma.
Differential Diagnoses
Carpal Tunnel Syndrome
Dupuytren Contracture
Rheumatoid Arthritis
Other Problems to Be Considered
Diabetes mellitus, particularly in patients with multiple trigger fingers
Ganglion involving the tendon sheath
Infection within the tendon sheaths
Ganglion cyst of the wrist
See also the following related Medscape topics:
CME Progression of Rheumatoid Arthritis
CME Evolving Treatment Outcomes in Rheumatoid Arthritis
Workup
Laboratory Studies
- As a rule, no lab tests are needed in the diagnosis of trigger finger. If there is a concern regarding an associated, undiagnosed condition, such as diabetes, rheumatoid arthritis, or another connective tissue disease, an assessment of, respectively, glycosylated hemoglobin (HgbA1c), fasting blood sugar, or rheumatoid factor should be ordered.
Imaging Studies
- Generally, no imaging studies are needed in cases of trigger finger.
Other Tests
- No further tests are usually required.
Procedures
- Injection of the trigger digit is generally considered to be therapeutic rather than diagnostic. (See Other Treatment.)
Treatment
Rehabilitation Program
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.
Medical Issues/Complications
- 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).6,7 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.8
- 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 be monitored by assessing sensation throughout the affected digit.
Surgical Intervention
- 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.9
- 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.9
Consultations
Surgical consultation for operative treatment may be required. Typically, such procedures are performed by an orthopedic hand surgeon or a plastic surgeon.
Other Treatment
- Corticosteroid injection in the area of tendon sheath thickening is considered to be the first-line treatment of choice for a trigger finger.9,10,11,12
- 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.13
- 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.8
- 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.14
- Although corticosteroid injection has traditionally been administered into the tendon sheath (but not into the tendon itself),7 studies now seem to indicate that subcutaneous injection may be as effective as the intrasheath approach.15,16 Additionally, in some cases, steroid injection into the subcutaneous tissue seems to result in better clinical outcomes than does injection into the sheath alone.15
See also the following related Medscape topic:
CME Improving NSAID Outcomes: Stratifying Risks and Tailoring Treatment (Slides with Audio)
Medication
For this musculoskeletal condition, medications are used primarily to decrease pain and inflammation in conjunction with the rehabilitation plan. Thus, the most common medication treatments are focal corticosteroid injection and the administration of NSAIDs.
Nonsteroidal anti-inflammatory drugs
Oral NSAIDs can help to decrease pain and inflammation. Various oral NSAIDs can be used, although none of these agents holds a clear distinction as the drug of choice. The choice of NSAID is largely a matter of convenience (how frequently doses must be taken to achieve adequate analgesic and anti-inflammatory effects) and cost.
Ibuprofen (Motrin, Advil, Nuprin, Rufen)
DOC for patients with mild to moderate pain. NSAIDs inhibit inflammatory reactions and pain by decreasing prostaglandin synthesis.
Dosing
Adult
200-800 mg PO tid/qid
Pediatric
<6 months: Not established
6 months to 12 years: 4-10 mg/kg/dose PO tid/qid
>12 years: Administer as in adults
Interactions
Coadministration with aspirin increases risk of inducing serious NSAID-related adverse effects; probenecid may increase concentrations and, possibly, toxicity of NSAIDs; may decrease effect of hydralazine, captopril, and beta blockers; may decrease diuretic effects of furosemide and thiazides; monitor PT closely (instruct patients to watch for signs of bleeding); may increase risk of methotrexate toxicity; phenytoin levels may be increased when administered concurrently
Contraindications
Documented hypersensitivity, peptic ulcer disease, recent GI bleeding or perforation, renal insufficiency, or high risk of bleeding
Precautions
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus
Precautions
Category D in third trimester of pregnancy; caution in congestive heart failure, hypertension, and decreased renal and hepatic function; to minimize risks of adverse effects, avoid taking multiple NSAIDs concurrently; caution in anticoagulation abnormalities or during anticoagulant therapy
Corticosteroids
In contrast to the widespread systemic distribution that occurs when an oral anti-inflammatory drug is administered, a local corticosteroid injection can achieve the focal placement of a potent anti-inflammatory agent at the site of maximal tenderness or inflammation. A variety of corticosteroid preparations are available. Commonly, the corticosteroid is mixed with a local anesthetic agent prior to injection. The clinician has numerous local anesthetic agents from which to choose.
Methylprednisolone (Depo-Medrol, Solu-Medrol, Medrol, Adlone)
Corticosteroids are commonly used in local injections administered to bursae or joints. The drugs provide a local anti-inflammatory effect while minimizing some of the GI and other risks of systemic medications.
Dosing
Adult
40 mg (1 mL), intralesionally, is common for injection at many sites; often mixed with a few mL of a local anesthetic, such as 1% lidocaine
Pediatric
Not established
Interactions
Local corticosteroid injection is not known to give rise to the same degree of medication interaction that oral or other systemic administration of corticosteroids produces; co-administration with anticoagulants may increase risk of hemorrhage or local bruising
Contraindications
Documented hypersensitivity; skin infection at the site of injection
Precautions
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
Never inject corticosteroids through an infected area of skin; diabetic patients may sometimes experience transient elevation of blood glucose level after a local corticosteroid injection
Follow-up
Further Outpatient Care
- The patient should return for a follow-up visit within 1-4 weeks. At this time, further treatment, such as splinting, repeat corticosteroid injection (but not within a few weeks of a previous injection), or surgical referral for severe, unresponsive cases should be considered. In addition, any complications from previous injections should be assessed.
Inpatient & Outpatient Medications
- Oral NSAIDs may be somewhat helpful.
Transfer
- Because injection is the primary treatment for trigger finger, physicians who are not trained or experienced in the administration of trigger finger injections and who are uncomfortable with performing them should consider transferring care to a skilled clinician.
Complications
- The complications of corticosteroid injection include the following:
- Infection
- Bleeding
- Tendon rupture
- Atrophy of subcutaneous fat
- Digital nerve injury
Prognosis
- The prognosis is very good; most patients respond to corticosteroid injection with or without associated splinting. Some cases of trigger finger may resolve spontaneously and then reoccur without obvious correlation with treatment or exacerbating factors.
- Patients who need surgical release generally have a very good outcome.
- The prognosis is also very good for congenital trigger thumb that is treated with resection of the tendon nodule.
Patient Education
- As with patient education following any local injection, patients should be told to watch for signs and symptoms of infection and bleeding. Any suggestion of infection or excessive bleeding should be reported to the physician immediately.
- Patients should understand that some increased tenderness may be noted at the injection site for 2-4 days, until the corticosteroid begins to have a significant therapeutic effect. If there is an inordinate amount of pain after the procedure, patients should contact the physician who performed the injection.
- Patients should understand that a certain amount of numbness in the digit may occur if some of the local anesthetic has come into contact with a digital nerve; however, the numbness should resolve within a matter of hours after the injection. Significant, persistent numbness should be reported to the physician who performed the injection.
- To minimize the risk of tendon rupture after corticosteroid injection, the patient should be advised that, for a few weeks following the injection, he/she should avoid using the injected structures for excessively strenuous or forceful activity.
Miscellaneous
Medicolegal Pitfalls
- Perhaps the most important differential diagnosis is infection, such as suppurative tenosynovitis. Any such infection requires immediate referral to a hand surgeon or plastic surgeon for aggressive management, which includes antibiotics and local procedures.
- Before injecting any medication, always withdraw on the syringe to ensure that the needle tip is not located within an intravascular space.
- Do not inject the corticosteroid solution if there is significant resistance to injection flow, which may indicate that the needle tip is in the tendon rather than just within the tendon sheath.
Special Concerns
- Pregnant patient - Splinting and local corticosteroid injection can be performed if the patient is pregnant. Surgical release of the A1 pulley is generally an elective procedure and is usually deferred until after delivery.
- Pediatric patient - In infants, the nodule on the flexor pollicis longus tendon can be resected with good results. Corticosteroid injections are generally not helpful in these cases of congenital trigger thumb.
- Elderly patient with a history of gastrointestinal problems or other complications from NSAIDs - Consider cyclo-oxygenase-2 (COX-2) inhibitors if oral NSAIDs are needed.
See also the following related Medscape topic:
CME GI Risks and Benefits of Traditional and COX-2-Selective NSAIDs
Multimedia
Media file 1: Flexor tendons pass within the tendon sheath and beneath the A-1 pulley at approximately the metacarpal head, beyond which they travel into the digit.
Media file 2: An inflamed nodule can restrict the tendon from passing smoothly beneath the A-1 pulley. If the nodule is distal to the A-1 pulley (as shown in this sketch), then the digit may get stuck in an extended position. Conversely, if the nodule is proximal to the A-1 pulley, then the patient's digit is more likely to become stuck in the flexed position.
Media file 3: A trigger finger often results in difficulty flexing or (in this case) extending the metacarpophalangeal joint of the involved digit.
References
Trigger finger. In: Snider RK, ed. Essentials of Musculoskeletal Care. Rosemont, Ill: American Academy of Orthopaedic Surgeons; 1997:249-53.
Strakowski JA, Wiand JW, Johnson EW. Upper limb musculoskeletal pain syndromes. In: Braddom RL, ed. Physical Medicine and Rehabilitation. Philadelphia, Pa: WB Saunders; 1996:756-82.
Breen TF. Wrist and hand. In: Steinberg GG, Akins CM, Baran DT, eds. Orthopaedics in Primary Care. 3rd ed. Baltimore, Md: Lippincott Williams & Wilkins; 1999:99-138.
Brinker MR, Miller MD. The adult hand. In: Fundamentals of Orthopaedics. Philadelphia, Pa: WB Saunders; 1999:196-220.
McGee DJ. Forearm, wrist and hand. In: Orthopedic Physical Assessment. 2nd ed. Philadelphia, Pa: WB Saunders; 1992:168-215.
Fitzgerald BT, Hofmeister EP, Fan RA, et al. Delayed flexor digitorum superficialis and profundus ruptures in a trigger finger after a steroid injection: a case report. J Hand Surg [Am]. May 2005;30(3):479-82. [Medline].
Jianmongkol S, Kosuwon W, Thammaroj T. Intra-tendon sheath injection for trigger finger: the randomized controlled trial. Hand Surg. 2007;12(2):79-82. [Medline].
Anderson B, Kaye S. Treatment of flexor tenosynovitis of the hand (''trigger finger'') with corticosteroids. A prospective study of the response to local injection. Arch Intern Med. Jan 1991;151(1):153-6. [Medline].
Nimigan AS, Ross DC, Gan BS. Steroid injections in the management of trigger fingers. Am J Phys Med Rehabil. Jan 2006;85(1):36-43. [Medline].
Fleisch SB, Spindler KP, Lee DH. Corticosteroid injections in the treatment of trigger finger: a level I and II systematic review. J Am Acad Orthop Surg. Mar 2007;15(3):166-71. [Medline].
Geiringer SR. Tendon sheath and insertion injections. In: Lennard TA, ed. Physiatric Procedures in Clinical Practice. Philadelphia, Pa: Hanley & Belfus; 1995:44-8.
[Best Evidence] Peters-Veluthamaningal C, Winters JC, Groenier KH, et al. Corticosteroid injections effective for trigger finger in adults in general practice: a double-blinded randomized placebo controlled trial. Ann Rheum Dis. Jan 7 2008;[Medline].
[Best Evidence] Baumgarten KM, Gerlach D, Boyer MI. Corticosteroid injection in diabetic patients with trigger finger. A prospective, randomized, controlled double-blinded study. J Bone Joint Surg Am. Dec 2007;89(12):2604-11. [Medline].
Nonsteroidal anti-inflammatory drugs (NSAIDs). In: Green SM, ed. Tarascon Pocket Pharmacopoeia 2000. Loma Linda, Calif: Tarascon Pub; 2000:11-2.
Akhtar S, Bradley MJ, Quinton DN, et al. Management and referral for trigger finger/thumb. BMJ. Jul 2 2005;331(7507):30-3. [Medline].
Taras JS, Raphael JS, Pan WT, et al. Corticosteroid injections for trigger digits: is intrasheath injection necessary?. J Hand Surg [Am]. Jul 1998;23(4):717-22. [Medline].
Keywords
trigger finger, digital flexor tenosynovitis, digital tenovaginitis stenosans, flexor tendon stenosing tenosynovitis, locked finger, stick palsy, trigger digit, trigger thumb, volar flexor tenosynovitis, flexor pollicis longus tendon nodule
Contributor Information and Disclosures
Author
Patrick M Foye, MD, FAAPMR, FAAEM, Associate Professor of Physical Medicine and Rehabilitation, Co-Director of Musculoskeletal Fellowship, Co-Director of Back Pain Clinic, Director of Coccyx Pain (Tailbone Pain, Coccydynia) Service, University of Medicine and Dentistry of New Jersey, New Jersey Medical School
Patrick M Foye, MD, FAAPMR, FAAEM is a member of the following medical societies: American Academy of Physical Medicine and Rehabilitation, American Association of Neuromuscular and Electrodiagnostic Medicine, Association of Academic Physiatrists, and International Spine Intervention Society
Disclosure: Nothing to disclose.
Coauthor(s)
Todd P Stitik, MD, Professor, Department of Physical Medicine and Rehabilitation, Acting Director of Sports Medicine, UMDNJ-New Jersey School of Medicine; Lead Physician, Practice Medical Director of University Hospital PM & R Clinic
Todd P Stitik, MD is a member of the following medical societies: American Academy of Physical Medicine and Rehabilitation, Association of Academic Physiatrists, Phi Beta Kappa, and Physiatric Association of Spine, Sports and Occupational Rehabilitation
Disclosure: Nothing to disclose.
Medical Editor
Robert E Windsor, MD, FAAPMR, FAAEM, FAAPM, President and Director, Georgia Pain Physicians, PC; Clinical Associate Professor, Department of Physical Medicine and Rehabilitation, Emory University School of Medicine
Robert E Windsor, MD, FAAPMR, FAAEM, FAAPM is a member of the following medical societies: American Academy of Pain Medicine, American Academy of Physical Medicine and Rehabilitation, American College of Sports Medicine, American Medical Association, International Association for the Study of Pain, Physiatric Association of Spine, Sports and Occupational Rehabilitation, and Texas Medical Association
Disclosure: Nothing to disclose.
Pharmacy Editor
Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: Nothing to disclose.
Managing Editor
Michael T Andary, MD, MS, Residency Program Director, Professor, Department of Physical Medicine and Rehabilitation, Michigan State University College of Osteopathic Medicine
Michael T Andary, MD, MS is a member of the following medical societies: American Academy of Physical Medicine and Rehabilitation, American Association of Neuromuscular and Electrodiagnostic Medicine, American Medical Association, and Association of Academic Physiatrists
Disclosure: Nothing to disclose.
CME Editor
Kelly L Allen, MD, Consulting Staff, Department of Physical Medicine and Rehabilitation, Lourdes Regional Rehabilitation Center, Our Lady of Lourdes Medical Center
Disclosure: Nothing to disclose.
Chief Editor
Rene Cailliet, MD, Professor-Chairman Emeritus, Department of Rehabilitation Medicine, University of Southern California School of Medicine; Former Director, Department of Rehabilitation Medicine, Santa Monica Hospital Medical Center
Rene Cailliet, MD is a member of the following medical societies: American Academy of Pain Medicine, American Academy of Physical Medicine and Rehabilitation, American Pain Society, Association of American Medical Colleges, International Association for the Study of Pain, and Pan American Medical Association
Disclosure: Nothing to disclose.