By My Linh Huynh, occupational therapist
Cause
Also known as hammer finger, mallet finger is caused by a rupture of the distal part of the extensor tendon, where the lateral bands converge. Once ruptured, the tendon can no longer perform its function of straightening the tip of the finger, creating what is called an extension lag at the distal interphalangeal joint. If left untreated, this injury can lead to an imbalance in the finger structures and progress into a boutonnière deformity.
Treatment
For most closed ruptures, mallet fingers are well treated conservatively by immobilizing the distal interphalangeal joint in an extended position for 6 to 8 weeks. The middle joint, the proximal interphalangeal joint, remains free during the treatment. Afterward, your occupational therapist will teach you how to begin mobilizing your finger in a controlled manner to avoid placing too much stress on the tendon that has just healed during the immobilization period. Typically, between the 10th and 12th week, you will begin to wean off your splint and gradually reintegrate the affected finger into your daily activities.
Results with conservative treatment
Geyman et al. mention that conservative treatment is effective for at least 80% of mallet finger injuries. Surgical interventions are usually indicated for open injuries (lacerations leading to a wound), more complex or chronic cases, or recurrent mallet fingers.
Why encourage occupational therapy
- Allows for the creation of a custom-made splint tailored to the client.
- Provides education on the cause of the issue and activities to avoid throughout the protocol.
- Helps prevent a boutonnière deformity.
- Guides the client in the progression of exercises and splint weaning to avoid an extension lag that can occur after the immobilization period.
References
Geyman, J. P., Fink, K., & Sullivan, S. D. (1998). Conservative versus surgical treatment of mallet finger: a pooled quantitative literature evaluation. The Journal of the American Board of Family Practice, 11(5), 382-390.
Skirven, T. M., Osterman, A. L., Fedorczyk, J., Amadio, P. C., Felder, S., & Shin, E. K. (2020). Rehabilitation of the hand and upper extremity. Elsevier Health Sciences.