INTRODUCTION
In my 20+ year career as a hand therapist, I have worked with a multitude of patients with trigger fingers (TFs) and trigger thumbs (TTs). I helped many patients resolve their symptoms with traditional hand therapy treatments, but I found the number of patients who reported ongoing or reoccurring symptoms to be perplexing. After 2-3 months of conservative treatment, I followed the recommendation to refer patients to a doctor to be evaluated for a corticosteroid injection or a surgical release.
My concern and question as a hand therapist became how I could help patients avoid injections and surgeries. I wanted to understand what underlying conditions increase the risk of developing TFs and TTs. The focus of most medical journals and hand therapy courses that I'd taken had been on the biomechanical causes of trigger finger and the relationship of trigger finger occurring with other conditions, such as diabetes. I did not find much written about the impact of nutrition on trigger finger, until recently. In my studies about Nutritional Therapy, I have learned how dietary habits and nutritional deficiencies can impact common inflammatory hand conditions, like tendinitis, carpal tunnel syndrome, and TF/TT. It is my personal and professional quest to educate my patients and clients, fellow hand therapists and other health professionals about the important role of nutrition in conjunction with traditional hand therapy.
EDUCATION GOALS
1) Describe the incidence, presentation, grading, etiology and associated diseases of TFs/TTs
2) Share traditional hand therapy treatments
3) Share statistics about cortizone injections and surgical options
4) Provide nutritional therapy recommendations
INCIDENCE
Trigger finger/thumb is one of the most common causes of hand pain in adults. The reported prevalence is 2.6 % of the general population and the average age of onset is 58 (1). It occurs 2-6 times more frequently in women (1). The lifetime risk of developing trigger finger increases to 10% in diabetics. The ring finger is most commonly affected, followed by the thumb (3). The other fingers can also be affected and some people develop multiple trigger digits.
PRESENTATION
The symptoms of trigger finger may begin as painless clicking with finger motion. Many patients report stiffness or swelling in the morning or that they wake up with the digit locked and then it loosens during the day. Others report painful catching or popping when using the finger. A painful nodule (firm bump) may be felt at the base of a big knuckle on the palm side of the hand. Some patients report a progressive loss of motion without ever developing the catching and locking of a “typical” trigger finger.
The Quinnell grading system is used to assess the clinical severity of TF. (1)
Grade 1: uneven movement of the finger or thumb
Grade 2: actively correctable = the catch/lock can be released with active movement
Grade 3: passively correctable = the locked digit will not release without help from another hand. Since this manipulation is very painful, patients tend to try to avoid triggering by reducing the motion and use of the involved finger.
Grade 4: fixed deformity = motion progressively decreases which creates secondary stiffness in the middle knuckle of the finger and eventually it gets stuck (a joint contracture)
ETIOLOGY
Trigger finger earns its name from the painful popping or clicking sound when the involved digit is bent and straightened. It was first described in 1850 by Notta (2).
The basic biomechanical explanation of why TF/TT occurs is due to of a difference in the diameters of a flexor tendon and its retinacular sheath. The sheath is a fibrous tunnel that surrounds the flexor tendon to give it a smooth and contained gliding surface. Each finger has 5-pulley system that is located inside the sheath. The pulleys are a series of fibrous bands called annular ligaments and cruciate pulleys. The thumb has a unique diagonally oriented band called the oblique pulley. These ligaments and pulleys hold the flexor tendons close to the bones to prevent “bowstringing". A simple analogy that I share with my patients/clients is that the pulley system is like the series of eyelets on a fishing pole. Eyelets prevent the line from pulling away from the pole when reeling in a fish. They provide stability which allows greater force to be applied to the line.
For those who like a more detailed description: TF/TT develops because of inflammation, hypertrophy, and scarring at the junction of the A1 ligament and flexor tendon. Hypertrophy is defined as the enlargement of a tissue (or organ) from the increase in the size of its cells. The A1 ligament receives the most friction with finger movement because it is the first band that the two flexor tendons pass under in fingers and the one flexor tendon of the thumb. With repetitive stress and overuse, the ligament can become irritated and inflamed. The body responds to the friction by thickening the pulley with tougher connective tissue to "strengthen" it and better withstand the compression stress (4). The increased thickness of the ligament puts greater pressure into the flexor tendon that glides closest to it which can lead to nodule formation on the tendon. This creates a negative feedback loop with both the A1 pulley and the flexor tendon growing thicker. The catch/trigger occurs when the tendon gets pinched while trying to glide under the thickened pulley. When there is also a lump on the flexor tendon, it becomes stuck because it is unable to go back under the A1 ligament. As you can see in the simplified image below (showing just one finger flexor tendon), the lump gets stuck on one side of the pulley and can become locked into flexion or extension. Getting stuck in flexion (after bending the finger/thumb) is most common.
ASSOCIATED CAUSES / DISEASES
"Overuse, diabetes, gout, acromegaly, renal disease, glycogen storage diseases, carpal tunnel syndrome, rheumatoid arthritis, and other rheumatoid and musculoskeletal disorders have been associated with TF. Thyroid dysfunction, particularly hypothyroidism and thyrotoxicosis, have also been associated with TF." (1) Carpal tunnel release has also been associated with the development of TF/TT, with Trigger Thumb being the most common. (1)
The lifetime risk of TF for the general population is most commonly reported to be 2.6%, compared to 10% for people with diabetes. However, other studies report rates of 1-2% for the general population and 10-20% for people with diabetes. Of all the patients presenting with TF, 25% are diabetic. Furthermore, around half of patients with diabetes will present with multiple TFs. The longer a patient has diabetes with a high HbA1c, the more likely they will be affected by a hand or shoulder disorder. Having an HbA1c level greater than 7% is an independent risk factor for developing TF. (1)
I found it interesting to learn that "although abnormal inflammation and swelling have been noted at the A1 pulley and flexor tendon, there does not seem to be an abundance of inflammatory infiltrate, but rather metaplasia". Metaplasia is defined as a change of cells to a form that does not normally occur in the tissue in which it is found. One of the inner layers of a healthy A1 pulley contain skinny spindle-shaped fibroblasts with elongated nuclei and compact parallel collagen bundles. By the time TF has progressed to a moderate level, the inner fibroblasts have become thinned and replaced by the fibrous tissue of chondrocytes with rounded nuclei. This abnormal response contributes to greater pressure between tendon and ligament, "which like other musculoskeletal disorders is exacerbated by hyperglycemia" (1) Hyperglycemia is defined as an excess of glucose in the bloodstream. This is commonly referred to as high blood sugar. I will write more about decreasing sugar consumption in the Nutritional Therapy section below.
HAND THERAPY TREATMENT
There are variety of treatments that Certified Hand Therapists commonly provide for TF/TT.
1) Modalities:
There are multiple modality options including hot packs, hot paraffin wax baths, ultrasound, iontophoresis. Heat and paraffin increase blood flow and flexibility of collagen tissue, which can help make stretching more effective. Ultrasound is a sound-wave current that vibrates cells in a manner that can decrease inflammation. Iontophoresis uses an electrical current from a battery-powered machine to diffuse steroid medication into the skin. The application of iontophoresis has fallen out of favor due to inconclusive evidence of efficacy.
2) Passive Range of Motion exercises (PROM):
These are stretches applied by using the other hand to move the affected digit into full flexion and extension in order to decrease stiffness and prevent joint contractures.
- Finger/Thumb stretches: If the digit remains relaxed, the joints can be moved by the other hand without catching because the tendon is not being pulled/moved inside the sheath by an active muscle contraction.
- Stretches for the long extrinsic flexor muscles, located in the forearm, to decrease tightness
- Stretches for the short intrinsic hand-based muscles: the interossei muscles that move the fingers side to side, and the lumbrical muscles that move the fingers from a claw position to a bird-beak position
- Isometrics for the long flexor tendon called the Flexor Digitorum Profundus.
For anyone living in the state of Oregon, I can provide Zoom video instruction of how to do these exercises and if you're in the Portland area we could meet in person. Reach out to me at Jessica@HolisticHandHealth.com
For those living elsewhere, here is a link to a You Tube video showing the top 3 Trigger Finger Exercises: https://www.google.com/search?q=trigger+finger+exercises&oq=trigger+finger+exercises&aqs=chrome..69i57j0i512l9.3686j0j7&sourceid=chrome&ie=UTF-8
3) Splinting:
I recommend patients utilize splints to completely avoid catching/locking for 6-8 weeks to let the irritated/thickened tissues calm down.
- "Ring" splint to limit full flexion (bending) during the day to prevent catching/locking
- Night extension splint to keep the middle knuckle of the finger straight at night
CORTIZONE & SURGERY
The following statistics come from A Critical Appraisal of Adult Trigger Finger article, published in 2019. The authors critically reviewed the efficacy and cost-effectiveness of the treatments methods for TF through a comprehensive search of the PubMed Database from 2003 to 2019.
The success rate of a single corticosteroid injection is reported to be 57%. Having a second injection, within a 6-month follow-up period, increase the success rate to 86%. Women with a single TF are most likely to have long-term success with a single injection. A study determined the 10-year success rate of women to be 56%, compared with 35% for men. For people with multiple TFs, the long-term success after single injection is 39% for women and 37% for men. Corticosteroid injections are believed to be less effective for patients with symptoms that have been present for more than 6 months (1).
Surgery is recommended after two failed injections. However, many surgeons and patients elect to forgo any injections and instead elect to have immediate surgery. An open surgical approach, with a longitudinal incision, has a success rate of 99%. A percutaneous release technique, which is done through a small puncture of the skin, has 74-94% success rate. The advantage of the percutaneous approach is that is it less invasive, which decreases the risk for infection, scar tissue, and finger stiffness. However, it has a higher risk of nerve damage. One study found persistent pain in as many as 50% of patients who underwent percutaneous release (1).
NUTRITIONAL THERAPY RECOMMENDATIONS
Here is what likely drew you to my website in the first place, because not many hand therapists nor orthopedic doctors talk about nutrition! Could these recommendations prevent the need for injections and surgeries...? While I cannot guarantee prevention, all of these recommendations will improve a person's overall health and hopefully make a difference in reducing and preventing Trigger Finger/Thumb issues.
1) Decrease sugar consumption:
Remember how diabetics have a much greater risk of developing TF/TT? Modern research has repeatedly shown that high sugar diets create inflammation in the body, which is an underlying cause of diabetes, obesity and many other chronic health conditions.
I encourage my patients/clients to cut out soda and other sugary drinks, including fruit juice. It's much better to eat a whole piece of fruit because the fiber and enzymes help slow down the release of sugar to the bloodstream. I also advise everyone to decrease their consumption of processed/packaged foods, which often contain High Fructose Corn Syrup and poor quality oils/fats. The bottom line is to try to avoid sugar as much as possible, which I know is much easier said than done. Sugar tastes so good and sets off a dopamine surge that is similar to the way the brain reacts to the ingestion of substance like heroin and cocaine, which is why we crave sugar and become addicted to it.
I also stress the importance of eating enough high-quality protein and healthy fats. I have written about these topics in other blog posts to support my patients/clients and other health professionals.
2) Focus on good hydration:
There is increasing evidence that even mild dehydration plays a role in the development of chronic diseases (4). To learn the ideal amount to drink for your body weight, please read my first blog post titled the #1 Ingredient for Healthy & Flexible Joints: https://www.holistichandhealth.com/blog-1
3) Boost Magnesium intake:
Magnesium is a mineral that helps muscles relax and allows the body to utilize calcium optimally. I remember being surprised when I learned that 50% of Americans are deficient in magnesium, which worsens to 80% of the elderly. Supplementing with Magnesium Glycinate, Mag L-Threonate or Magnesium Citrate can be helpful. A standard dosage of 250-300 mg before bed is recommended, however, some people may need higher doses. It is important to note that the citrate/carbonate form (found in a powdered supplement called Natural Calm) has a laxative effect. I personally take Magnesium Glycinate because it is one of the most absorbable forms of magnesium. As a Nutritional Therapist, I tailor the dosage and form of Magnesium to fit each client’s needs.
4) Boost Vitamin B6 intake:
B6 vitamin is involved in over 150 enzyme reactions in the body. It directly impacts the body's ability to utilize magnesium, which means supplementing with magnesium alone is often not enough. A B6 deficiency has been linked to increased pain perception. Supplementation of activated B6 (P5P ) at 20-50 mg, 3 times daily, is recommended (6). It is important to choose a supplement with the activated P-5-P form of B6, which stands for Pyridoxal-5-Phosphate. I recommend my patients with trigger finger/thumbs to take activated B6 for 2-3 months. It can take up to 6 weeks to notice an effect.
4) Avoid Yellow Dye No. 5 and Tartrazine Derivatives:
"Yellow Dye No. 5 and Tartrazine inhibit B6 metabolism, which leads to the deficiency that can cause trigger finger. Yellow dye #5 can be found in soft drinks, certain beverages, baked goods, breakfast cereals, processed vegetables, chips, pickles, honey, mustard, gelatin desserts, pudding, ready to use frostings, dessert powders, candy, gums, cosmetics, and in certain medicines and other foods" (7). This is why is it so important to read labels completely. Yellow Dye #5 is also called Tartrazine.
5) Boost Vitamin B12 intake:
When it comes to B12 supplementation, there is a wide range of recommended dosage. I hesitate to recommend a specific dosage without an individual evaluation. Foods high in B12 in include mollusks (clams, oysters, scallops), crustaceans (crab, shrimp), fish (herring, sardines, salmon, trout, tuna), beef, eggs, fortified nutritional yeast, milk and dairy products (for those can tolerate lactose), nori (seaweed), and shiitake mushrooms.
6) Eliminate or decrease gluten consumption:
This is a huge player in many chronic health conditions. A team of researchers, led by Dr. Fasano at the University of Harvard Celiac research center, "suggests that a protein in gluten, gliadin, is not only indigestible, but also that it causes inflammation – via intestinal permeability – in all who eat it." (8) I would like to stress the last five words: in ALL who eat it. Intestinal permeability is commonly known as Leaky Gut, which leads to nutritional deficiencies and inflammation. Gluten intolerance in a major factor in Rheumatoid Arthritis and other auto-immune conditions that affect the joints.
There are many methods for testing gluten intolerance but currently there is no gold standard. A simple blood test can screen people for celiac disease but they must be currently eating a diet that includes gluten for it to be accurate. You can learn more about gluten intolerance/allergy testing options in this Healthline article: https://www.healthline.com/health/gluten-intolerance-test
7) Boost Vitamin D:
People living in northern/southern latitudes that are more than 37 degrees from the equator are at high risk for Vitamin D deficiency. It is very common and most people are unaware of it. The symptoms are often subtle and non-specific, but they can include muscle weakness/aches/cramps, pain, fatigue and depression. It is important to have vitamin D levels checked once a year to tailor supplementation dosage.
8) Homeopathic options:
According to Dr. Vikas Sharma, MD the best homeopathic medicines for trigger finger are: Rhus Tox, Ruta Graveolens, Arnica Montana, Causticum, Merc Sol, and Sulphur (10). Please refer to his article titled Homeopathic Treatment for Trigger Finger to learn about these and recommended dosages. https://www.drhomeo.com/homeopathic-treatment/homeopathic-treatment-trigger-finger/#
CONCLUSION
All hand therapists know that many trigger fingers and thumbs do not fully resolve with conservative treatment and that symptoms often reoccur. I believe, in many cases, that this is due underlying nutritional issues not being addressed. Providing education about hydration and nutritional therapy, along with traditional treatments, will increase effectiveness in reducing and preventing the reoccurrence of trigger finger and thumb.
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ABOUT HOLISTIC HAND HEALTH
I enjoy working with individual patients & clients as a OT Hand Therapist and Nutritional Therapist to blend traditional and holistic therapies. I have learned the importance of addressing the root nutritional issues behind symptoms and conditions. I provide comprehensive evaluations and treatment plans with tailored recommendations. I approach each person as a unique bio-individual and include both dietary and lifestyle encouragement.
REFERENCES
1) Brozovich, Nikolas MD; Agrawal, Devandra PhD, MBA; Reddy, Gangadasu MD, MS, FACS. A Critical Appraisal of Adult Trigger Finger: Pathophysiology, Treatment, and Future Outlook. Plastic and Reconstructive Surgery - Global Open: August 2019 - Volume 7 - Issue 8 - p e2360
2) Makkouk, A, Oetgen, M, Swigart C, Dodds, S. Trigger finger: etiology, evaluation, and treatment. Cur Rev Musculoskelet Med. 2008 Jun; 1(2): 92-96. Published online 2007 Nov 27. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2684207/
3) Blazar P.E., Aggarwal, R. Trigger finger (Stenosing Flexor Tenosynovitis). 2019. UpToDate. com https://www.uptodate.com/contents/trigger-finger-stenosing-flexor-tenosynovitis
4) Manz F, Wentz A. The importance of good hydration for the prevention of chronic diseases. Nutr Rev. 2005; 63(6 Pt 2): S2-S5.
5) Tucker, J. The Trigger Thumb Tendonitis Dynamic. 2018. Tendonitisexpert.com https://www.tendonitisexpert.com/trigger-thumb.html
6) Dach, J. Vitamin B6, Pyridoxine for Trigger Finger and Carpal Tunnel. 2014. Drdach.com http://www.drdach.com/Vitamin_B6_TriggerFinger.html
9) Ferrara PE, Codazza S, Maccauro G, Zirio G, Ferriero G, Ronconi G. Physical therapies for the conservative treatment of the trigger finger: a narrative review. Orthop Rev (Pavia). 2020 Jun 26;12(Suppl 1):8680.
10) Sharma, Vikas. Homeopathic Treatment for Trigger Finger