Today I want to discuss Mallet Finger – a common finger injury that is a lot easier to treat right the FIRST time in order to prevent the potential consequences of delaying treatment and avoid surgery.
What is it?
Mallet finger usually occurs due to a trauma where the tip of your finger is forced into a bent (flexed) position (such as when “catching” a basketball with the tip of your finger) or is forced backwards into hyper-extension (such as when “blocking” a volleyball or falling onto your hand). Sports are so often involved in the mechanism of injury that mallet finger is also commonly known as “baseball finger”!
These forces can result in either:
the tearing of the extensor tendon that attaches to the outermost bone (distal phalanx) in your finger that usually helps straighten the finger…
OR an avulsion fracture – where the extensor tendon pulls away part of the bone in your distal phalanx…
TAKE HOME MESSAGE #1: This is why it’s always important to go to your doctor ASAP to get an Xray or other diagnostic imaging to check for bone damage.
NOTE: Sometimes a mallet finger can also occur very slowly over time. If the tissues on the underside (palmar aspect) of the finger contract (such as if you had a scar or skin graft), they “pull” the tip of the finger into a bent position, gradually over-stretching the extensor tendon on top.
How do I know if I have it?
1. You will have pain predominantly at the outermost joint in your finger (called the Distal Interphalangeal or DIP joint).
2. You can bend the DIP joint by yourself, but CANNOT straighten the finger without assistance (such as using your other hand or a table). This problem is called an “extension lag”.
What can I do about it?
1st Step – Get your doctor to check if there’s a fracture or other causes for your pain.
2nd Step – Splinting for 6-8 weeks! The goal behind splinting is to hold the DIP joint in extension or sometimes slight hyperextension. This allows the ends of the delicate extensor tendon to reattach and heal in a tight position and/or the bone fragment to reattach to the rest of the distal phalanx.
A quick Google search reveals that there are a wide variety of mallet splints available – from smaller splints that block only the DIP joint (ie STAX or Oval 8’s), to full finger splints that block both joints in the finger. Talking to your doctor or physiotherapist can help determine which splint is right for you.
The good news is that this injury generally heals well with conservative treatment and is most effective the sooner (ie within the first few days) your finger is splinted.
TAKE HOME MESSAGE #2: The most crucial factor in mallet finger healing is keeping the DIP joint supported in a straight position 100% of the time for the first 6-8 weeks.
If the digit is allowed to bend (even once!), the delicate tendon will likely get overstretched and the treatment could fail. THIS IS THE IMPORTANT PART: Never. Allow. The Joint. to BEND. at ANY point during this first 6 weeks!
Your physiotherapist can help you learn to safely remove your splint without bending the DIP joint and develop strategies to practice skin care.
At the 6 to 8-week mark, your physiotherapist will guide your transition out of the splint and help you safely and gradually regain your normal finger range of motion.
Developing Chronic Mallet Finger
Despite our best efforts, sometimes life just happens - fingers get accidentally bent, treatments get delayed…what happens then?
If the finger bends during this initial period, usually a second or third round of non-stop finger splinting is repeated. But unfortunately, sometimes this is unsuccessful and you are left with a permanent “drop finger”. This usually doesn’t limit functional use of your hand if your extension lag is 20˚ or less.
However, this permanent bending of the DIP joint, can result in hyperextension of the next joint, making a “Swan-neck deformity”.
Surgery may be required if your extension lag is 40˚ or more, is significantly affecting your function (especially as a musician), and/or you’ve tried splinting without success.
Long story short, from a physiotherapy perspective, it’s a lot easier and more effective to treat this condition the right way, the first time. Don’t try to do it alone – having a medical professional (whether it be a doctor or physiotherapist) to help guide the process can help maximize your treatment outcome!
If you have more questions about mallet finger or any other upper extremity condition, feel free to book a Telehealth appointment with me at InReach Physiotherapy!
By: Susan Herdman, Registered Physiotherapist – specializing in upper extremity and hand rehabilitation.
Book a telephysio / online physio / virtual physio / video physiotherapy appointment with a registered physiotherapist in British Columbia. InReach Online Physio services communities in northern and rural BC, such as Masset, Queen Charlotte, Fraser Lake, Fort Nelson, Fort St James, Dease Lake, Fort St John, Dawson Creek, the Gulf Islands, and more!
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Holtkamp K - OrthoIllinois (2016). Mallet Finger Rehabilitation Protocol conservative Management. Accessed Oct 15, 2021: https://www.orthoillinois.com/wp-content/uploads/2016/12/ExtensorTendonIConservativeMalletFinger2017.pdf
Lamaris GA & Matthew MK (2017). The diagnosis and management of mallet
finger injuries. AAHS HAND; Vol 12(3), p 223-228. DOI: 10.1177/1558944716642763. Accessed Oct 15, 2021: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5480656/pdf/10.1177_1558944716642763.pdf
Solomon G (2020). Chapter 25: Finger Sprains and Deformities in Wietlisbach’s Cooper’s Fundamentals of Hand Therapy: Clinical Reasoning and Treatment Guidelines for Common Diagnoses of the Upper Extremity (3rd Edition, pp. 320-337). St. Louis, Missouri: Elsevier.
Willoughby JA, Foister RD, & Cummings BJ (2016). Chapter 21: Extensor Tendon Imbalance: Mallet Finger, Swan-Neck Deformity, Boutonniére Deformity in Saunders, Astifidis, Burke, Higgins, & McClinton’s Hand and Upper Extremity Rehabilitation: A Practical Guide (4th Edition, pp. 205-218). St. Louis, Missouri: Elsevier.
Mallet finger deformity: Wikimedia: Howcheng (2008 June 28) The middle finger of this hand shows a condition called mallet finger. https://commons.wikimedia.org/wiki/File:Mallet_finger.jpg
Swan-neck deformity: Wikimedia: Couch-scratching-cats (2021 Aug 17) Slight swan-neck deformation on the finger of a person with hypermobility, this deformation can also be seen by the silhouette of my finger's shadow caused by the camera flash. https://commons.wikimedia.org/wiki/File:Swan_neck_deformation_finger.jpg