Episode 231: Trigger Finger — From Clicking to Treatment Dr. Awa and Dr. Dadzie present an overview of trigger finger, including clinical presentation, diagnosis and treatment. They reinforce the importance of conservative management. Dr. Arreaza asks insightful questions and reminds us of the risks of corticosteroid injections. Written by Mokom Awa, MD. Comments by Ebenezer Dadzie, MD. Edits by Hector Arreaza, MD. You are listening to Rio Bravo qWeek Podcast, your weekly dose of knowledge brought to you by the Rio Bravo Family Medicine Residency Program from Bakersfield, California, a UCLA-affiliated program sponsored by Clinica Sierra Vista, Let Us Be Your Healthcare Home. This podcast was created for educational purposes only. Visit your primary care provider for additional medical advice.
Dr. Arreaza: Welcome to another episode of Rio Bravo qWeek. Today we're talking about a condition that is common in primary care, usually easy to diagnose, but can be surprisingly painful and frustrating for patients: trigger finger.
You know the patient—the finger clicks, catches, sometimes locks, and suddenly opening a jar becomes very difficult. Today we are going to talk about what causes trigger finger, how to recognize it, what else can look like it, and most importantly, how we treat it. Joining me today are two family medicine residents who will help us walk through the topic. Please introduce yourself.
Dr. Awa: [Introduce yourself.]
Dr. Dadzie: [Introduce yourself.]
Dr. Arreaza: Excellent. Let's start with the basics. What exactly is trigger finger?
Dr. Awa: Trigger finger, also called “stenosing flexor tenosynovitis,” is a mechanical problem involving the flexor tendon and the pulley system of the finger. The flexor tendon normally glides smoothly through a series of pulleys that keep the tendon close to the bone during finger movement. The important structure in trigger finger is the first annular pulley, or A1 pulley, located near the metacarpophalangeal, or MCP, joint.
Dr. Dadzie: When the tendon and surrounding tissue become enlarged or the pulley becomes narrowed, the tendon has difficulty gliding through that space. It can catch as the finger flexes or extends.
Dr. Arreaza: So essentially, the tendon is trying to pass through a space that has become too tight?
Dr. Awa: Exactly. And that mechanical catching is what produces the characteristic clicking, snapping, or locking.
Dr. Dadzie: The underlying histologic change is also interesting. The A1 pulley can develop changes in the fibers and cartilage, which contribute to narrowing of the canal.
Dr. Arreaza: Trigger finger may be associated to several conditions, mostly inflammatory and metabolic disorders, right?
Dr. Dadzie: Yes, but most cases are idiopathic. Patients often associate their symptoms with repetitive activity, but the evidence for repetitive occupational activity as a direct cause is controversial.
Dr. Arreaza: Let’s describe a typical patient with trigger finger.
Dr. Awa: It's common in adults, with a prevalence of roughly 2 percent in the general population. It is more common in women, particularly during the fifth and sixth decades of life. It can involve one finger or multiple fingers, and it can affect both hands.
Dr. Arreaza: And what medical conditions should make us think about trigger finger?
Dr. Dadzie: Diabetes mellitus is an important association. Trigger finger is also more common in patients with rheumatoid arthritis and in some systemic disorders, including amyloidosis.
Dr. Arreaza: Let's move to the classic presentation. The classic story is clicking, catching, or locking of a finger during flexion or extension.
Dr. Awa: Correct. Initially, the triggering may be painless. Over time, patients can develop pain, especially around the volar aspect of the MCP joint, and they may have difficulty extending the finger after it catches.
Dr. Dadzie: Some patients notice symptoms particularly in the morning. They may wake up with a finger locked in the palm and then gradually regain movement as the day goes on.
Dr. Arreaza: Some cases are mild, but we can also have a severe presentation.
Dr. Dadzie: Yes, the finger can become locked in flexion and require passive manipulation to straighten it. That can be quite painful. If the patient avoids moving the finger because of pain or locking, they can eventually develop a secondary contracture, particularly at the proximal interphalangeal, or PIP, joint.
Dr. Arreaza: Trigger finger is primarily a clinical diagnosis that does not require imaging.
Dr. Awa: Yes, we can ask the patient to open and close the hand and try to reproduce the triggering. With the palms facing upward, we watch for catching, clicking, or locking.
Dr. Dadzie: We can also palpate over the A1 pulley near the MCP joint. There may be tenderness or a palpable nodule caused by thickening of the tendon.
Dr. Arreaza: So if we can reproduce the clicking and the patient is tender right over the A1 pulley, that's pretty easy. Have you read about the use of ultrasound for these patients?
Dr. Dadzie: Ultrasound isn't required for most patients, but it can be useful when the diagnosis is uncertain or when we want to guide an injection. Dynamic ultrasound can demonstrate a thickened A1 pulley and can sometimes show the tendon catching as it moves beneath the pulley.
Dr. Arreaza: That sounds neat. US are our new eyes.
Dr. Dadzie: X-rays or MRI are generally not necessary for a straightforward case. Radiographs or CT may occasionally show calcification, while MRI can help identify alternative tendon or soft-tissue pathology, but MRI isn't particularly useful for directly evaluating the A1 pulley.
Dr. Arreaza: Good. So, don’t order x-rays or MRI for trigger finger, but we can have some mimics. Let's talk about the differential diagnosis. A patient has a painful finger that doesn't move normally. What else should we consider?
Dr. Awa: One important alternative is Dupuytren's contracture (dOOp-itrens).
In trigger finger, the loss of motion is typically dynamic—the finger catches and releases. With Dupuytren's, the loss of extension is fixed and progressive, and there are usually nodules or cords in the palmar fascia.
Dr. Arreaza: So dynamic versus fixed is an important distinction between trigger finger vs Dupuytren contracture.
Dr. Awa: Exactly.
Dr. Dadzie: Another possibility is diabetic cheiroarthropathy, or limited joint mobility associated with diabetes. This usually affects multiple fingers more symmetrically and causes difficulty flexing or extending the joints rather than the episodic catching seen with trigger finger.
Dr. Arreaza: What if the patient had an injury, does it change our approach?
Dr. Dadzie: Then we should think about an MCP joint sprain or another traumatic injury. A history of trauma and absence of triggering would point away from classic trigger finger.
Dr. Arreaza: Infection is a differential we should not miss, especially because an infection in the hands may be an emergency.
Dr. Awa: Absolutely. Infectious flexor tenosynovitis is an important diagnosis not to miss.
It presents with severe pain, tenderness, swelling, erythema, and symptoms extending along the flexor tendon—especially after a puncture wound or bite—should raise concern for infection. Unlike uncomplicated trigger finger, infection can rapidly cause significant loss of function and tendon damage.
Dr. Arreaza: Yes, an infection will require urgent evaluation and surgical consultation because a closed-space infection of the tendon sheath may require drainage. Excellent. Any other mimics?
Dr. Dadzie: Calcific periarthritis or peritendinitis can cause severe pain and inflammation and may mimic infection, but it generally doesn't cause the characteristic triggering. Inflammatory tenosynovitis, such as that associated with rheumatoid or reactive arthritis, can also cause pain and swelling along the tendon. The distribution and underlying inflammatory disease help distinguish it from trigger finger.
Dr. Arreaza: As a summary, differential diagnosis include: Dupuytren's contracture, diabetic cheiroarthropathy, trauma and infections. Now let's get to the part that our audience has been waiting for. After we diagnose a patient with trigger finger, and we ruled out other possible causes, how do we treat it? What's our first move?
Dr. Awa: Start conservatively. Activity modification and splinting are reasonable initial treatments. The patient doesn't necessarily need to stop all activity, but they should avoid movements that aggravate the symptoms, particularly repetitive pinching or grasping.
Dr. Arreaza: Tell us more about splinting?
Dr. Dadzie: Splinting can reduce triggering by limiting motion of the affected digit. Different splint designs can be used depending on the patient's triggering pattern and preference.
A typical trial is around six to ten weeks.
For milder cases, buddy taping the affected finger to an adjacent finger can also be considered.
Dr. Arreaza: The splint should be used 24 hours a day, and the splint that is best tolerated by patients is the MCP joint blocking orthosis, but you can also use a PIP joint blocking splint, which can actually be more effective for pain relieve and improvement of function.
Splinting is especially useful when injection is relatively contraindicated—e.g., diabetics with poor glycemic control, given the risk of steroid-induced hyperglycemia, and children. And what about medications?
Dr. Awa: NSAIDs can be used for short-term pain relief when appropriate. Typically, we would limit their use to about two to four weeks and consider contraindications such as gastrointestinal disease, kidney disease, or heart disease.
Dr. Dadzie: It's important to remember that NSAIDs treat the pain; they don't necessarily correct the mechanical problem causing the triggering.
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