Investigation of the Flexor Tendon Gliding Pattern in Normal and Trigger Digits Using Ultrasound Imaging

Abstract

The role of finger tendon excursion during rehabilitation protocol is to avoid the adhesion phenomenon which occurs at tissue or tendon repair In previous studies the main focus of these investigations were cadaveric or static study there were few studies measuring tendon excursion in-vivo that have been made in intraoperative observations electromyography or ultrasound Currently the maximum tendon excursion and the tendon excursion pattern on active finger motion were varied in different study that did not have a main reference There is a common disease seen in hand clinics called trigger finger or stenosing tenosynovitis Patients who suffer from trigger finger present discomfort during finger movement The discomfort is caused by the size discrepancy between flexor tendons and annular pulley system which results in greater resistance “Triggering” the sudden release phenomenon during finger extension movement when the tendon passes through the affected region The tendon nodule is a swelling of the flexor tendon resulting in constriction of the flexor tendon sheath triggering occurs when deformation of the tendon is induced Due to different motions different tendon gliding patterns maybe improve the triggering We are interested in understanding this possibility The purpose of this study is to use ultrasonography kinematic and kinetic analysis to obtain the tendon gliding pattern during different active finger motion and use this technique to evaluate the triggering condition of trigger finger patients In the study we recruited 19 healthy subjects who did not have any hand disease or injury and 7 trigger finger patients The finger motions we used are active fist motion and a modified tendon gliding exercise First participants were asked to flex and extend their finger in the neutral speed; another motion was a specific finger motion similar with tendon gliding exercise In the initial stage participants were ask to extend all finger joints and then sequentially flex MP PIP DIP joints to their maximum angles Next participants will extend MP PIP DIP joints to the initial position In the case of patients in addition to the above motion the passive pulling test was done in order to observe the relationship between tendon gliding and joint angle at triggering moment In this test we will use a string to pull the affected finger passively from a flexed posture to an extended posture The motion data and ultrasound image will be collected simultaneously The force data was collected in the passive pulling test The tendon excursion normalized tendon excursion versus differential joint angle FDS/FDP excursion ratio were used to evaluate the relationship between tendon and joint angle and between each flexor tendons As a result the characteristic are similar at the maximum joint angle between each active finger motion For active fist motion FDS/FDP excursion ratio show decrease with larger finger flexion angle which means FDP tendon play a more important role at larger flexion angles For the modified tendon gliding exercise the result shows FDS tendon made larger excursion at phase 1 with respect to FDP tendon The adjusted excursion ratio shows different patterns at all assigned phases between active fist motion and modified tendon gliding exercise This characteristic may be reference data for the future work In the patient study using ultrasound and external force to find that the relationship between performance of external force and tendon movement on image This is a potential method to evaluate the tendon performance of trigger finger at triggering moment In the current study we used ultrasonography to evaluate the relationship between tendon gliding and joint angle on healthy subjects and trigger finger patients and used passive pulling tests to estimate condition of triggering Further the tendon excursion pattern was building to become a reference to help evaluation of rehabilitation and hand research This model might be a safe and direct method to evaluate the finger movement pattern of trigger finger in the future

Date of Award	2014 Aug 27
Original language	English
Supervisor	Fong-chin Su (Supervisor)