A 50-year-old male presents to the emergency department with a new inability to extend his 5th digit of the left hand. He states he was playing a game of pick-up basketball last week when he jammed the finger while attempting to catch a pass from a teammate. An AP and lateral radiograph of the digit is obtained (Image 1 courtesy of Dr Alborz Jahangiri, Radiopaedia.org). What is your diagnosis? What causes this injury? What exam maneuver can help diagnose the underlying injury before the deformity is evident? What is the treatment/management of this injury? What are the surgical indications?
Boutonniere deformity – flexion of the proximal interphalangeal joint (PIP) and extension of the distal interphalangeal joint (DIP). Note the associated avulsion fracture at the PIP.
Trauma / inflammatory conditions (eg. rheumatoid arthritis) leading to tearing / weakening of the central slip extensor tendon and triangular ligament. See Image 2.
- Pearl: In this case, a traumatic avulsion (jammed finger) caused the central slip rupture. Loss of the central slip tendon prevents full PIP extension
- Pearl: PIP extension can still occur with the lumbricals and lateral slip tendons. The pull of the lumbricals will become unopposed during a central slip rupture, causing a volar extended DIP [1].
Image 2: Injury to the central slip tendon leading to a boutonniere deformity. Author’s own image.
- Use the Elson test or the Modified Elson test to help diagnose a central slip injury before the patient presents with a deformity of the finger.
- Weak, isolated PIP extension with an extended DIP
Early diagnosis prevents permanent deformation or loss of function of the finger.
- Splint the PIP joint in full extension for 6 weeks
- Do not remove the splint at any time
- With an associated avulsion fracture, this patient will likely require a primary central band repair. This necessitates follow-up with hand/orthopedics within the week, if possible [2].
Most chronic boutonniere deformities do not require surgery.
- Acute displaced avulsion fracture
- Acute closed injuries not amenable to PIP splinting
- Open fracture
- In patients that suffered this injury secondary to rheumatoid arthritis, a PIP arthrodesis may be required [2].
Resources and References
Check out the rest of the SplintER archives.
- Souter WA. The Problem of Boutonniere Deformity. Clinical Orthopaedics and Related Research. 1974;104:116-133. PMID: 4607222
- Strauch RJ. Extensor Tendon Injury. Green’s Operative Hand Surgery. 2011:159-188. doi:10.1016/b978-1-4160-5279-1.00006-x
Author information
The post SplintER Series: A Jammed Finger appeared first on ALiEM.