Please confirm topic selection

Are you sure you want to trigger topic in your Anconeus AI algorithm?

Please confirm action

You are done for today with this topic.

Would you like to start learning session with this topic items scheduled for future?

Updated: May 22 2021

Hypothenar Hammer Syndrome

Images[1]_moved.jpg angio.jpg
  • summary
    • Hypothenar Hammer Syndrome is post-traumatic digital ischemia from thrombosis of the ulnar artery at Guyon's canal.
    • Diagnosis is made with vascular studies including Doppler ultrasound and CT angiography.
    • Treatment can be observation, fibrinolysis, vessel ligation or reconstruction depending on the chronicity of symptoms, the digital brachial index, and the presence of an aneurysm. 
  • Epidemiology
    • Incidence
      • rare
        • < 1 per 100,000
    • Demographics
      • male: female ratio is 9:1
      • age bracket is 40s-50s
    • Anatomic location
      • unilateral, dominant ring finger +/- small finger
      • less commonly, index and middle fingers
      • thumb is spared
    • Risk factors
      • occupations using vibrating tools such as carpenters, machinists, mechanics
      • sports such as baseball catchers, mountain biking, golf, volleyball, karate
  • Etiology
    • Pathophysiology
      • mechanism
        • single or repetitive blunt impact on hypothenar eminence leads to ulnar artery thrombosis or aneurysm
        • hook of hamate functions as an anvil, causing thrombosis
        • distal embolisation leads to ulceration, gangrene
  • Anatomy
    • Ulnar artery
      • ulnar artery branches into 2 branches as it exits Guyon's canal
        • deep branch
        • superficial palmar arch in Guyon's canal
      • relation to hook of hamate
        • over distal 2cm, the artery is directly anterior to the hook of the hamate, covered by palmaris brevis, subcutaneous tissue and skin
  • Presentation
    • History
      • occupational or sporting risks (see above)
    • Symptoms
      • pain over hypothenar eminence and ring finger
        • may involve small, middle and index fingers
      • cold sensitivity
      • paresthesia
    • Physical exam
      • inspection
        • blanching, mottling, cyanosis, pallor, gangrene
        • tenderness over hypothenar eminence
        • prominent callus (calloused skin over hypothenar eminence)
        • pulsatile mass if aneurysm is present
        • fingertip ulcerations over ulnar digits
        • splinter hemorrhages over ulnar digits
      • provocative tests
        • Allen's test
          • positive if occlusion is present
          • negative if an aneurysm is present
  • Imaging
    • Doppler ultrasound
      • indications
        • first line test
        • measure digital brachial index
          • <0.7 necessitates reconstruction
    • Angiogram, CT angiogram or MR angiogram
      • indications
        • mandatory for diagnosis
      • findings
        • tortuous "corkscrew" ulnar artery
        • occlusion or aneurysm at the hook of the hamate
  • Differential
    • Raynaud's disease 
      • involves the thumb (hypothenar hammer syndrome does not)
  • Treatment
    • Nonoperative
      • lifestyle modifications, symptomatic treatment, and vascular consult
        • indications
          • thrombosis without aneurysm > 2 weeks
          • asymptomatic
          • no threat of digital loss
        • lifestyle modifications
          • smoking cessation
          • avoid recurrent trauma
        • outcomes
          • 80% success
    • Operative
      • endovascular fibrinolysis
        • indications
          • thrombosis without aneurysm < 2 weeks
      • excision of involved segment and reconstruction with or without a vein graft
        • indications
          • digital brachial index <0.7
          • thrombosis with aneurysm
          • ischemia in multiple digits
          • failed conservative treatment with recurrent symptoms
      • arterial ligation (Leriche procedure)
        • indications
          • digital brachial index >0.7
1 of 1
1 of 3
Private Note

Attach Treatment Poll
Treatment poll is required to gain more useful feedback from members.
Please enter Question Text
Please enter at least 2 unique options
Please enter at least 2 unique options
Please enter at least 2 unique options