Morphological Imaging and Biomechanics of Pulley and Trigger Finger

  • 楊 岱樺

Student thesis: Doctoral Thesis


Technology has increased the value of hand function and the occurrence of hand conditions of which trigger finger is one of the most common Yet important questions about diagnosis and treatment remain One question is the relationship between the flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) In our first study (Chapter 2) we investigated this relationship by creating a closed-system model Ten human cadaveric hands were mounted individually on our custom frame with the third finger’s flexor tendons looped through a mechanical pulley connected to a force transducer Individual joint motions and free joint movement were tested from rest to maximal flexion Joint range of motion tendon excursion and acquired loading force were recorded and the moment arm calculated The FDP contributed more than the FDS in individual proximal interphalangeal joint (PIP) motion but less in individual metacarpophalangeal joint (MCP) motion The FDP also played a greater role in free joint movement The findings about differences in finger performance and excursion amounts between the FDS and FDP provide important insights into hand modeling and treatment design Another question involves the correlation between pathological grading and clinical classification Treatment has depended on clinical severity evaluation but supporting pathological evidence is unestablished In our second study (Chapter 3) we investigated the correlation between clinical classification and pathological changes using tissue abnormality in microscopic images Images of tissue samples were randomly selected and graded A custom image analysis system was used to derive the size ratio of the abnormal tissue region and the number ratio of the abnormal nuclei Significant correlations were found between these parameters and pathological grading and between the parameters and clinical severity classification and good consistency was found between pathological and clinical classification These correlations can support treatment strategy development and this system can improve severity evaluation The final question relates to identifying the A1 pulley sonographically for proper percutaneous release The third study’s purpose (Chapter 4) was to identify the normal pulley’s exact location and thickness in sonographic images by comparing measurements from a clinical high-frequency ultrasound system (CHUS) a customized high-frequency ultrasound imaging research system (HURS) and a digital caliper Ten human cadaveric hands were used We inserted guide pins between the flexor tendons and A1 pulley of a randomly chosen and dissected ring finger recovered the finger and scanned it with the CHUS using anatomic structures for reference After identifying the pulley on the image we measured each long finger’s thickness using the CHUS Then we excised this pulley and measured its thickness with a digital caliper and the HURS The guide pins revealed the thin hypoechoic layer to be the synovial fluid space between the hyperechoic pulley and flexor tendons We also defined the pulley’s boundaries The significantly lower thickness measurement from the CHUS compared to the digital caliper and HURS indicated the HURS’s greater accuracy These new data can help the precise identification of the pulley Answering these questions should improve the diagnosis and treatment of this widespread hand disease thus improving many lives
Date of Award2015 May 4
Original languageEnglish
SupervisorFong-chin Su (Supervisor)

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