||Clinical Applications of Ultrasonography in
Carpal Tunnel Syndrome and Trigger Finger
||Department of BioMedical Engineering
carpal tunnel syndrome
carpal tunnel pressure
腕隧道症候群與扳機指為兩種非常常見的手部疾患，且兩者有一定程度的共病性。而腕隧道症候群的致病機制可能是腕管(carpal tunnel)內的腕管壓力的升高所導致。目前，其中一種治療方法是以腕管減壓術為主，透過切開橫腕骨韌帶來治療腕隧道症候群。而扳機指患者在掌指關節附近常有疼痛感且伴隨著手指頭於彎曲和伸直時在 A1 滑車近端區域有卡住、夾住或彈響的感覺。其中A1 滑車-肌腱系統的不相稱可能是引發扳機指的機制。在本論文中，研究設計分為三個部分，除了透過超音波輔助手術技術治療這些疾病外，更利用此一特殊手術方式來量測腕管內的壓力及評估A1 滑車-肌腱系統的不相稱現象，分別描述如下：
超音波導引經皮腕隧道鬆解：本部分研究的目的是呈現利用超音波輔助經皮腕管解離手術(percutaneous carpal tunnel release, PCTR）技術治療腕隧道症候群患者及其臨床結果。方法：我們使用先前於大體研究中所定義的解剖標誌包含安全區、定位、大小估計和橫腕韌帶的範圍，於91 位腕隧道症候群患者使用此一手術技術。追蹤包括四個時間點（1 週、2 個月、6 個月和12 個月），最終隨訪時間平均為22.5 個月。結果：感覺異常在治療後1 週、2 個月、6 個月和12 個月時分別減少約76.8%、93.4%、100%和100%。24.2%患者在1 週內曾有過中度疼痛，至2 個月內為6.6%，治療後12 個月內則僅剩1.1%。在最終隨訪時，兩隻手腕被評為不滿意：一隻手腕中度疼痛，但無感覺異常，另一隻手腕治療後14 個月復發。無治療中或治療後併發症狀。結論：超音波輔助經皮腕管解離手術是一種安全且有效的方法，但技術要求高，需要接受嚴密的教育與訓練才能熟悉使用。腕管壓-預後相關性：由於較少相關文獻提出利用超音波導引穿刺法研究超音波輔助經皮腕管解離手術對腕管壓力的影響，並建立腕管壓力與臨床結果之間的關係。因此，這部分研究的目的是評估腕管壓力的臨床結果與經超音波輔助經皮腕管解離手術治療後正中神經橫截面積的相關性。方法：一系列原發性腕隧道症候群患者量測術前、術後腕管壓力，及評估超音波下正中神經橫截面積和波士頓腕隧道量表直至治療後12 個月。結果：在超音波輔助經皮腕管解離手術後，36 例病患之37 隻症狀手的腕管壓力有顯著下降。對於輕度和中度神經電生理分級的患者，治療後的腕管壓力較低，腕管壓力降低率較高。手術後，波士頓腕隧道量表分數在一個月的追蹤中顯著改善，正中神經橫截面積直到3 個月的追蹤才顯著改善。術前腕管壓力與術前正中神經橫截面積評分和正中神經橫截面積顯著正相關。直到手術後12 個月，術後即時的腕管壓仍與正中神經橫截面積顯著正相關，但僅與術後1 個月的波士頓腕隧道量表分數成正相關。結論：術後即時的腕管壓可能可以用於預測短期術後功能性結果和正中神經橫截面積。肌腱-A1 滑車不對稱：本部分研究的目的是：利用非侵入性的超音波系統探討屈指肌腱的橫截面積和A1 滑車的厚度於扳機指與對側正常指分別於手指彎曲與伸直兩種姿勢下的相對關係。方法：本研究檢查了17 位扳機指患者的患側手指與對側正常手指。分別在掌指關節0°和彎曲60°時兩種姿勢觀察屈指肌腱及A1 滑車的超音波影像。結果：與對側正常手指相比，在掌指關節0°和彎曲60°時扳機指屈指肌腱橫截面積及A1滑車厚度皆顯著增加。此外，扳機指A1 滑車厚度於掌指關節彎曲60°時明顯大於彎曲0°時，但屈指肌腱橫截面積無論在哪種角度皆無顯著差異。結論：我們的結果顯示扳機指會造成A1 滑車增厚的和較大的屈指肌腱橫截面積。而扳機指在掌指關節彎曲時，A1 滑車與屈指肌腱橫截面積的不對稱變化可能是造成扳機現象的原因。
Carpal tunnel syndrome (CTS) and trigger digit (TD) both are common hand disorder with a significant co-incidence. The elevated carpal tunnel pressure (CTP) within the carpal tunnel is a possible mechanism to result in the CTS. Carpal tunnel release is one of the treatments for CTS by transecting the transverse carpal ligament (TCL) to relieve the symptoms of CTS. The patients with TD usually present pain at the metacarpophalangeal(MCP) joint and locking, catching or snapping sensation at the proximal portion of first annular (A1) pulley of the affected finger during flexion and extension. The mismatch of the A1 pulley-tendon sheath system is a possible mechanism to cause the triggering phenomenon. In this thesis, study designs were divided into three parts. The concept of these studies is to solve the clinical scenario using ultrasonography. We treated CTS and TD using ultrasonography-assisted percutaneous release in our daily practice, and furthermore measured the CTP using the unique technique. Finally, we evaluated the mismatch of the A1 pulley-tendon sheath system using ultrasonography. The three parts were described as follows:US-assisted PCTR:The purpose of this part of the study is to present the technique and the results of an ultrasonographically guided percutaneous carpal tunnel release (PCTR) in a consecutive series of patients with carpal tunnel syndrome. Methods: We used previously defined landmarks with the "safe zones", localization, estimated size, and extent of the transverse carpal ligament for this prospective clinical study of 91 consecutive cases of carpal tunnel release treated with this technique. The follow-up consisted of four time points(1 week and 2, 6, and 12 months) and a final evaluation in an average 22.5 months. Results:
The sensory disturbances disappeared in 76.8, 93.4, 100, and 100% of the patients in 1 week and 2, 6, and 12 months postoperatively, and 24.2% experienced moderate pain within 1 week, 6.6% within 2 months, and 1.1% within 12 months after the operation. In the final evaluation, two hands were graded as unsatisfactory: one had moderate wrist pain without sensory disturbance and one had a recurrence 14 months after the operation. There was no intra- or postoperative complication. Conclusions: Ultrasonographically assisted PCTR is a safe and effective procedure, but it is technically demanding and requires substantial training to be proficient in its use. CTP-outcomes correlation: Since there were no studies to investigate the effect of ultrasonographically guided percutaneous carpal tunnel release (UCTR) on CTP by percutaneous ultrasound-guided needle puncture method and establish the relationship between CTP and clinical outcomes.The aim of this part of the study is to evaluate the correlation of carpal tunnel pressure (CTP) with clinical outcomes and cross-sectional area of median nerve (CSAMN) following ultrasonographically guided percutaneous carpal tunnel release (UCTR). Methods: Serial patients with idiopathic CTS were enrolled. CSAMN under ultrasound examination and Boston Carpal Tunnel Questionnaire (BCTQ)
were evaluated until twelve months postoperatively. Results: The CTP in 37 hands of 36 patients significantly decreased after UCTR. There were the lower post-operative CTP and the higher decrease ration of CTP in patients with the mild and moderate electrodiagnostic grades. After surgery, BCTQ score significantly improved at one-month follow-up, and CSAMN did not significantly improve until three-month follow-up. The pre-operative CTP was significantly positively correlated with pre-operative BCTQ score and CSAMN. The immediately post-operative CTP was still significantly positively correlated with CSAMN until twelve months after surgery, but only with post-operative BCTQ at one-month followup.
Conclusions: Therefore, the immediate postoperative CTP might predict the short-term postoperative functional outcomes and CSAMN. Tendon-A1 pulley mismatch: The aim of this study was to evaluate and to compare the cross-sectional area (CSA) of flexor digitorum tendons and the thickness of A1 pulleys between contralateral normal digits and trigger digits at positions of finger flexion and extension using a noninvasive ultrasound system. Methods: Seventeen affected fingers of seventeen trigger finger patients who involved the trigger finger in one hand were examined in this study. Seventeen contralateral normal digits without symptoms of trigger finger were
examined. The sonographic appearances of flexor digitorum tendons and A1 pulley were observed at two positions of 0˚ and 60˚ metacarpophalangeal (MCP) joint flexion. Results:
The findings of this study indicate that CSA of flexor digitorum tendons and A1 pulley thickness were significantly larger in both positions of 0° and 60° flexion of MCP joint compared to contralateral normal digits (p< 0.01). In trigger digits, there was a significantly thicker A1 pulley at 60° flexion of MCP joint than that at 0° flexion (p< 0.01), but no
significant change on CSA of flexor tendons. Conclusions: Our results suggested that trigger digits lead to the thicker A1 pulley and larger CSA of the flexor digitorum tendons. The mismatch in volume change between CSA of flexor digitorum tendons and A1 pulley
thickness during MCP flexion may lead to the trigger phenomenon.
摘要 ····································································· I
Abstract ································································ III
致謝 ····································································· VI
Content ································································· VII
List of Table ··························································· XI
List of Figure ·························································· XII
Chapter 1 Introduction ··················································· 1
1.1 RESEARCH BACKGROUD ······································· 2
1.1.1 Carpal tunnel syndrome (CTS) ······························· 2
1.1.2 CTS and carpal tunnel pressure(CTP) ······················ 2
1.1.3 Trigger digit (TD) ··············································· 3
1.2 MOTIVATIONS AND OBJECTIVES ··························· 4
1.2.1 US-assisted PCTR ··············································· 4
1.2.2 CTP-outcomes correlation ····································· 5
1.2.3 Tendon-A1 pulley mismatch ··································· 5
Chapter 2 Ultrasonographically Guided Percutaneous Carpal
Tunnel Release: Early Clinical Experiences and Outcomes · 6
2.1 INTRODUCTION ···················································· 7
2.2 MATERIALS AND METHODS ··································· 9
2.2.1 Patient population ··············································· 9
2.2.2 Instruments and operative technique ························ 9
2.2.3 After-care ························································· 18
2.2.4 Assessing the result and outcome measurement ··········· 18
2.3 RESULTS ······························································· 20
2.3.1 US-assisted PCTR ··············································· 20
2.3.2 Symptomative relief and postoperative pain and tenderness
2.3.3 Sensory and strength testing··································· 21
2.3.4 Scar and wound healing ······································· 24
2.3.5 Complications ···················································· 24
2.3.6 Final outcomes ·················································· 24
2.4 DISCUSSIONS ························································ 25
2.5 CONCLUSION ························································ 30
Chapter 3 The Correlation Of Carpal Tunnel Pressure With
Clinical Outcomes Following Ultrasonographically-Guided
Percutaneous CarpalTunnel Release ································· 31
3.1 INTRODUCTION ···················································· 32
3.2 MATERIALS AND METHODS ··································· 34
3.2.1 Participants ······················································· 34
3.2.2 Carpal tunnel pressure measurement and percutaneous
ultrasound-guided carpal tunnel release ··························· 34
3.2.3 CSA of median nerve and Functional Outcome ··········· 35
3.2.4 Statistical analysis ······························································· 36
3.3 RESULTS ······························································· 37
3.3.1 Demographic data ··············································· 37
3.3.2 Outcomes after UCTR ························································· 37
3.3.3 Correlation among CTP, CSA of median nerve, and functional
outcomes ······················································································· 38
3.4 DISCUSSIONS ························································ 44
3.5 CONCLUSIONS ······················································ 48
Chapter 4Effect of Metacarpophalangeal Joint Positionon A1 Pulley
and Flexor Digitorum Tendons in Trigger Digits ············· 49
4.1 INTRODUCTION ···················································· 50
4.2 MATERIALS AND METHODS ··································· 52
4.2.1 Patients ···························································· 52
4.2.2 Ultrasound examination and measurements ····················· 54
4.2.3 Statistical analysis ······························································· 55
4.3 RESULTS ······························································· 56
4.3.1 Trigger digits versus normal digits ··························· 56
4.3.2 The effect of MCP posture ·················································· 56
4.4 DISCUSSIONS ························································ 59
4.5 LIMITATIONS ························································ 61
4.6 CONCLUSIONS ······················································ 61
References ····································································· 62
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