You are here

Swan Neck Deformity M20.039 736.22

swan-neck deformity 
ICD-9 Classification / Treatment
Etiology / Natural History Associated Injuries / DDx
Anatomy Complications
Clinical Evaluation Follow-up Care
Xray / Diagnositc Tests Review References


Swan Neck Deformity ICD-10

Swan Neck Deformity ICD-9

  • 736.22 Swan Neck Deformity 736.22

Swan Neck Deformity Etiology / Epidemiology / Natural History

  • Characterized by hyperextension of the PIP joint and flexion of the DIP joint 
  • Affects approximately 14% of patients with established rheumatoid arthritis (Boyer MI, JAAOS 1999;7:92)
  • Generally caused by tenosynovitis and synovitis in the finger and PIP joint

Swan Neck Deformity Anatomy

  •  The volar plate, collateral ligaments, and flexor digitorum superficialis allows the PIP joint to hyperextend due to extensor mechanism forces.  The deforming forces may be accentuated by intrinsic contracture/tightness related to MCP joint flexion and volar subluxation.
  • DIP joint synovitis may rupture the terminal extensor tendon which worsens the PIP hyperextention

Swan Neck Deformity Clinical Evaluation


Swan Neck Deformity Xray / Diagnositc Tests


Swan Neck Deformity Classification / Treatment

  •  Nalebuff Type I: flexible hyperextension of the PIP joint.  RX: 
  • Nalebuff Type II: tightness of the intrinsic muscles causes limitation of PIP joint flexion when the MCP joint is maintained in extension.
  • Nalebuff Type III: limited PIP joint flexion in all MCP joint positions due to the inability of the lateral bands to translate volar to the axis of rotation of the PIP joint.
  • Nalebuff Type IV: destruction of the articular surface of the PIP joint
  • Treatment options: see (Boyer MI, JAAOS 1999;7:92)

Swan Neck Deformity Associated Injuries / Differential Diagnosis


Swan Neck Deformity Complications

Swan Neck Deformity Follow-up Care


Swan Neck Deformity Review References  




The information on this website is intended for orthopaedic surgeons.  It is not intended for the general public. The information on this website may not be complete or accurate.  The eORIF website is not an authoritative reference for orthopaedic surgery or medicine and does not represent the "standard of care".  While the information on this site is about health care issues and sports medicine, it is not medical advice. People seeking specific medical advice or assistance should contact a board certified physician.  See Site Terms / Full Disclaimer