II. Mechanism

  1. Central slip tears over PIP dorsum
    1. See Hand Anatomy
  2. Commonly occurs with ball striking dorsal finger
    1. Actively extended PIP joint forced into flexion
    2. Common basketball dislocation
  3. May also occur with volar dislocation of pip joint
  4. Images
    1. FingerExtensorTendonInjury.png

III. Signs

  1. See Hand Injury
  2. See Hand Exam
  3. See Elson Extensor Tendon Test
  4. PIP joint diffusely tender and swollen
  5. Maximal pain at midline dorsal proximal middle phalanx
  6. Pain on resisted finger extension
    1. Hold the PIP joint at 15-30 degrees flexion
    2. Patient unable to actively extend finger
    3. Passive extension still possible
  7. Inability to extend DIP joint when PIP is held in flexion
    1. centralSlipDIPExtensionTest.jpg
    2. Suggests central slip injury
  8. Assess for associated collateral ligament injury

IV. Imaging: XRay finger

  1. Normal in most cases
  2. Small proximal middle phalanx avulsion Fracture

V. Management

  1. Orthopedic referral indications
    1. Avulsion Fracture involving >1/3 of joint
    2. Passive extension of PIP not possible
  2. First 6 weeks
    1. Splint PIP joint in full extension
      1. Aluminum splint (do not use stack splint)
    2. Must maintain PIP extension continuously
      1. If PIP falls into flexion, 6 weeks starts again
    3. Daily passive range of motion of DIP joint
    4. May participate in sports if PIP remains splinted
  3. After 6 weeks
    1. Range of motion of PIP into full flexion

VI. Complications: Boutonniere Deformity

  1. Occurs when central slip injury not splinted
    1. Extensor slip lateral bands migrate to volar pip
    2. Develops weeks after initial injury
  2. Characteristics
    1. PIP Flexion contracture
    2. DIP and MCP hyperextension

VII. References

  1. Shamseldin (2003) AAFP Board Review, Seattle
  2. Leggit (2006) Am Fam Physician 73(5):810-23 [PubMed]

Images: Related links to external sites (from Bing)

Related Studies

Ontology: Boutonnière deformity (C0158476)

Concepts Acquired Abnormality (T020)
ICD9 736.21
ICD10 M20.02
SnomedCT 203553004, 43234007
English Boutonniere deformity finger, Boutonniere deformity of finger, acquired boutonniere deformity of finger (diagnosis), acquired boutonniere deformity of finger, boutonniere deformity (physical finding), boutonniere deformity, boutonniere deformities, boutonnieres deformity, Boutonniere deformity of finger (disorder), Boutonnière deformity (disorder), Boutonnière deformity, boutonnière deformity, Boutonniere deformity
Dutch boutonniere of knoopsgatmisvorming van vingers
French Déformation en boutonnière
German Boutonniere-Deformitaet
Italian Deformazioni a bottoniera
Portuguese Deformação em botoeira
Spanish Deformidad en ojal, deformidad en ojal (trastorno), deformidad en ojal
Japanese ボタン穴変形, ボタンアナヘンケイ
Czech Boutonnierova deformita
Hungarian Boutonniere-deformitás