The thickness of the A2 pulley and the flexor tendon are related to the severity of trigger finger: results of a prospective study using high-resolution ultrasonography

A Cadaveric Study Examining the Accuracy of Wireless Hand-Held Guided Ultrasound Injections Versus Blind Injections in the Flexor Tendon Sheath

Purpose

Hand-held ultrasound (HHUS) is gaining popularity among clinicians. Although its use for procedural guidance could have several advantages in hand surgery, other surgeons may wonder about its added benefits. This cadaveric study aimed to examine the hypothesis of increased accuracy of wireless HHUS-guided injections versus that of blind injections into the flexor sheath.

Methods

Our series included 20 fresh cadaveric hands with 80 fingers randomly assigned to 2 groups. In group A, 10 hands were randomly assigned to receive a landmark injection and then received a blinded injection to the flexor tendon sheath (FTS). In group B, 10 hands were blinded in the same manner and received an ultrasound-guided injection with HHUS. Methylene blue was injected, and anatomic dissection was performed to evaluate the injection accuracy based on the dye's filling pattern in the FTS as stage I (no filling), stage II (<50% filling), and stage III (>50% filling). Statistical analysis was performed, and P <.05 indicated a significant difference.

Results

One finger was excluded because of severe Dupuytren contracture. In group A, 39 blind injections of the FTS were performed, with 82% (32/39) fingers achieving stage III filling. In group B, 40 ultrasound-guided FTS injections were performed, with 90% (36/40) of fingers achieving stage III filing. Our study did not reveal any superiority in accuracy when ultrasound guidance was used (P = .35).

Conclusions

Hand-held ultrasound-guided FTS injections were not more accurate than blind injections performed by an experienced hand surgeon. These findings suggest that blind injections can be used as routine practice when performed by experienced operators to treat trigger finger. However, the use of HHUS may offer other advantages in hand surgery practice.

Clinical relevance

Ultimately, choosing to perform HHUS-guided injection versus blind injection to treat trigger finger depends on the surgeon's experience and preference for a particular technique.

High HbA1c Levels Are Associated With Development of Trigger Finger in Type 1 and Type 2 Diabetes: An Observational Register-Based Study From Sweden

OBJECTIVE

Trigger finger (TF) is a hand disorder causing the fingers to painfully lock in flexion. Diabetes is a known risk factor; however, whether strict glycemic control effectively lowers risk of TF is unknown. Our aim was to examine whether high HbA1c was associated with increased risk of TF among individuals with diabetes.

RESEARCH DESIGN AND METHODS

The Swedish National Diabetes Register (NDR) was cross-linked with the health care register of the Region of Skåne in southern Sweden. In total, 9,682 individuals with type 1 diabetes (T1D) and 85,755 individuals with type 2 diabetes (T2D) aged ≥18 years were included from 2004 to 2019. Associations between HbA1c and TF were calculated with sex-stratified, multivariate logistic regression models with 95% CIs, with adjustment for age, duration of diabetes, BMI, and systolic blood pressure.

RESULTS

In total, 486 women and 271 men with T1D and 1,143 women and 1,009 men with T2D were diagnosed with TF. Increased levels of HbA1c were associated with TF among individuals with T1D (women OR 1.26 [95% CI 1.1-1.4], P = 0.001, and men 1.4 [1.2-1.7], P < 0.001) and T2D (women 1.14 [95% CI 1.2-1.2], P < 0.001, and men 1.12 [95% CI 1.0-1.2], P = 0.003).

CONCLUSIONS

Hyperglycemia increases the risk of developing TF among individuals with T1D and T2D. Optimal treatment of diabetes seems to be of importance for prevention of diabetic hand complications such as TF.

Sonographic Location of Distal A1 Pulley by Means of a Bony Acoustic Landmark on the Proximal Phalanx: An Anatomic Study

PURPOSE

To identify the anatomic relationship between the distal extent of the A1 pulley and the distalmost insertion point of the palmar plate into the base of the proximal phalanx at a metaphyseal bony ridge, the "P1 peak" (P1P), which is a bony acoustic landmark easily identifiable on sonography of the finger.

METHODS

We studied 48 fingers (no thumbs) from 12 fresh frozen cadavers with high-resolution ultrasound. A 20-gauge hypodermic needle was directed perpendicular to the long axis of the tendon sheath along a plumb line drawn at the level of the bony flare of the proximal metaphyseal-diaphyseal junction of the proximal phalanx, or the P1P, under high-resolution ultrasound guidance. Dissection was then performed, and the distance of the needle barrel and the actual distance of the P1P from the distal edge of the A1 pulley were recorded.

RESULTS

The study demonstrated that accurate placement of the needle within 1 mm of the actual P1P was possible using ultrasound guidance and that the P1P was within 1 mm of the distal edge of the actual A1 pulley in all specimens studied.

CONCLUSIONS

In all the specimens studied, we found that the P1P may be used as a clearly identifiable sonographic reference landmark to identify the distal extent of the A1 pulley.

CLINICAL RELEVANCE

Using the P1P landmark as a guide to judge the completeness of ultrasound-guided percutaneous trigger finger release may reduce the risks of incomplete distal release and inadvertent release of the A2 pulley.

Adhesions as a component of the trigger finger: a dynamic sonographic study

We performed a detailed dynamic high-resolution ultrasound examination of the flexor tendons in trigger fingers and compared this with normal contralateral digits. There was a loss of defined linear tendon margins and/or traction of the flexor tendons on the surrounding soft tissue during passive flexion of the distal interphalangeal joint in 17 out of 20 trigger fingers, which indicated adherence to the surrounding tissues. The differential motion between the flexor digitorum profundus tendon and the flexor digitorum superficialis tendons was also lost in ten trigger fingers, which suggested adherence between the tendons. No signs of peritendinous or intertendinous adhesions were found in the healthy control fingers. We conclude that tendon adhesions are present in the majority of trigger fingers. We could not determine a relationship between the severity of triggering and the presence of adherence due to limited sample size.Level of evidence: II.

Current Concepts in the Management of Advanced Trigger Finger: A Critical Analysis Review

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While the majority of patients with trigger finger obtain excellent outcomes from nonoperative treatment or release of the A1 pulley, a subset of patients with advanced trigger finger, defined as trigger finger with loss of active or passive range of motion, may have incomplete symptom relief and warrant specific attention.

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Advanced trigger finger is more refractory to complete symptom resolution from corticosteroid injection, and particular attention should be paid to incomplete improvement of flexion contractures.

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Unlike simple trigger finger, the pathology in advanced trigger finger involves not only the A1 pulley but also the flexor tendon, including thickening and degeneration.

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Progression toward surgical intervention should not be delayed when nonoperative measures fail, and specific attention should be paid to persistent inability to achieve full extension following A1 pulley release.

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Facing substantial residual flexion contracture, reduction flexor tenoplasty and partial or complete resection of the superficialis tendon followed by hand therapy and splinting may be needed to allow patients to regain reliable full range of motion.

Ultrasound findings of finger, wrist and knee joints in Mucopolysaccharidosis Type I

INTRODUCTION

Musculoskeletal findings in MPS can progress after enzyme replacement. Our aim was to examine synovial recesses, tendons, retinacula and pulleys using ultrasonography for structural and inflammatory changes.

MATERIAL AND METHODS

The wrist, metacarpophalangeal (MCP), proximal and distal interphalangeal (PIP and DIP) joints, the finger flexor tendons and the knee including entheses of quadriceps and patella tendons were assessed clinically. Ultrasonography of the various synovial recesses of the wrist as well as the extensor retinaculum, carpal tunnel, MCP, PIP and DIP joints of the second finger, extensor and flexor tendons, A1-5 pulleys and the knee joint including relevant entheses followed. Significance of differences between patient values and available normative data were assessed using t-tests.

RESULTS

Ultrasonography showed significant abnormal intraarticular material in the wrist without a clear distribution to synovial recesses and without effusions. Doppler signals were found in a perisynovial distribution and not intrasynovial as expected in in inflammatory arthritis. Findings were similar in the knee but not the fingers. Flexor and extensor tendons were also mostly normal in their structure but significant thickening of retinaculae and the flexor tendon pulleys was seen (p<0.0001 compared to normal).

CONCLUSION

MPS I patients showed intraarticular deposition of abnormal material in the wrist and knee but not in the finger joints where significant thickening of retinaculae/pulleys controlling tendon position was dominant. No ultrasound findings of inflammatory pathology were demonstrated but rather a secondary reaction to abnormal deposition and direct damage of GAG.

Trigger finger in children with hurler syndrome - distribution pattern and treatment options

Introduction: Mucopolysaccharidosis is a rare and congenital autosomal recessive lysosomal storage disorder of glycosaminoglycans. An enzyme defect leads to cell, tissue and organ dysfunction. Carpal tunnel syndrome and trigger finger are the results of mucopolysaccharid deposition.

Material and methods: We are treating 6 patients with mucopolysaccharide associated trigger fingers in an interdisciplinary setting with the department of pediatric hematology and oncology at Hannover Medical School, where each patient is examined inter alia for symptoms of trigger finger annually.

Besides an interview of the parents about abnormalities with regard to hand function, pain and/or neurologic symptoms the children are examined by palpation and by assessment of the active and passive range of finger motion.

In the case of finger locking due to an impaired excursion of the flexor tendons in the A2 and A3 pulley region, we performed a trap-door incision technique for A2 pulley widening and a simple release of the A3 pulley.

Results: In 6 patients 43 fingers were affected. The average age was 10 years. Pulley thickening was palpated in 19 fingers of to the left hand and 24 fingers of the right hand. In 7 fingers the A1 pulley was affected, in 28 fingers the A2 pulley and in 25 fingers the A3 pulley. The A4 and A5 pulley were not affected in any case. Trigger symptoms were seen in 13 fingers. Five of the 6 children were given an operation indication. In these cases we performed carpal tunnel release, release of Loge de Guyon, and trigger finger release, either in combination or alone. In all cases the procedure led to pain relief and functional improvement.

Conclusion: The treatment of trigger fingers in children with mucopolysaccharidosis as a rare disease is challenging with regard to diagnostics and indication.

The main treatment goal is pain relief and improvement of hand function.

Segmentation of finger tendon and synovial sheath in ultrasound image using deep convolutional neural network

BACKGROUND

Trigger finger is a common hand disease, which is caused by a mismatch in diameter between the tendon and the pulley. Ultrasound images are typically used to diagnose this disease, which are also used to guide surgical treatment. However, background noise and unclear tissue boundaries in the images increase the difficulty of the process. To overcome these problems, a computer-aided tool for the identification of finger tissue is needed.

RESULTS

Two datasets were used for evaluation: one comprised different cases of individual images and another consisting of eight groups of continuous images. Regarding result similarity and contour smoothness, our proposed deeply supervised dilated fully convolutional DenseNet (D2FC-DN) is better than ATASM (the state-of-art segmentation method) and representative CNN methods. As a practical application, our proposed method can be used to build a tendon and synovial sheath model that can be used in a training system for ultrasound-guided trigger finger surgery.

CONCLUSION

We proposed a D2FC-DN for finger tendon and synovial sheath segmentation in ultrasound images. The segmentation results were remarkably accurate for two datasets. It can be applied to assist the diagnosis of trigger finger by highlighting the tissues and generate models for surgical training systems in the future.

METHODS

We propose a novel finger tendon segmentation method for use with ultrasound images that can also be used for synovial sheath segmentation that yields a more complete description for analysis. In this study, a hybrid of effective convolutional neural network techniques are applied, resulting in a deeply supervised dilated fully convolutional DenseNet (D2FC-DN), which displayed excellent segmentation performance on the tendon and synovial sheath.

Open Surgery for Trigger Finger Required Combined a1-a2 Pulley Release. A Retrospective Study on 1305 Case

OBJECTIVES

We retrospectively reviewed 1305 open-surgery for idiopathic trigger finger performed by 4 senior hand surgeons between 2014 and 2016.

MATERIAL AND METHODS

Medical records and a telephone interview made with a minimum follow-up of 1 year were used to identify the recurrent rate of triggering and other complications.

RESULTS

This retrospective study let us note that 169 fingers (13%) required simultaneous release of the A1-A2 pulleys because the sectioning of the A1 pulley alone did not lead to complete free sliding of the tendons. We did not record any bowstring complication and we ascribe this to both surgery and bandaging technique. Overall rate of complication was 11.8% and relapse triggering or permanent proximal interphalangeal joint flexion (PPIJF) were among them; notably, however, they occurred only in patients where the A2 pulley was not sectioned.

CONCLUSIONS

Is possible to reduce the percentage of relapse triggering or PPIJF after trigger finger surgery, by performing that combined A1-A2 pulley release.

LEVEL OF EVIDENCE

Level III.

Ultrasound Features of Trigger Finger: Review of the Literature

Trigger finger is a common pathologic condition of the digital pulleys and flexor tendons in the hand. The key clinical finding is a transient blockage of the digit when it is flexed with subsequent painful snapping when it is extended. Imaging is a helpful guide for establishing the severity of the disease, identifying the underlying cause, and deciding the appropriate management. This narrative review aims to recall the anatomic and pathologic bases and describe the ultrasound features of trigger finger, also including common ultrasound findings and complications after therapy. Ultrasound enables an accurate static and dynamic evaluation of trigger finger as well as a comparison with the adjacent normal digits and thus should be considered the radiologic modality of first choice for its diagnosis.

Effect of metacarpophalangeal joint position on A1 pulley and flexor digitorum tendons in trigger digit

BACKGROUND

The aim of this study was to evaluate and compare the cross-sectional area (CSA) of flexor digitorum tendons and the thickness of first annular (A1) pulleys between contralateral normal digits and trigger digits (TDs) at positions of finger flexion and extension using a noninvasive ultrasound system.

METHODS

Seventeen affected fingers of 17 patients (6 men and 11 women) with TDs in one hand, and 17 contralateral normal digits without trigger finger symptoms were examined. The sonographic appearances of flexor digitorum tendons and A1 pulleys were observed at two positions of metacarpophalangeal (MCP) joint flexion: 0° and 60°.

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 with contralateral normal digits (p < 0.01). In TDs, 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.

CONCLUSION

Our results suggested that TDs 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.

A Critical Appraisal of Adult Trigger Finger: Pathophysiology, Treatment, and Future Outlook

Trigger finger (TF) is a common referral to a hand surgeon, with people with diabetess being the most at-risk population. Abnormal thickening, scarring, and inflammation occur at the A1 pulley and flexor tendon, and histological changes correlate well with the clinical severity of TF. Corticosteroid injections decrease the thickness of the A1 pulley and are considered a first-line treatment. However, corticosteroids are only moderately effective, especially for people with diabetes. Patients may elect for surgery if nonoperative treatments prove ineffective; some may choose immediate surgical release instead. To release the A1 pulley, patients have the option of an open or percutaneous approach. The open approach has a greater risk of infection and scar tissue formation in the short run but an overall superior long-term outcome compared with the percutaneous approach.

METHODS

We critically reviewed the efficacy and cost-effectiveness of the treatment methods for TF through a comprehensive search of the PubMed Database from 2003 to 2019.

RESULTS

To reduce costs, while still delivering the best possible care, it is critical to consider the likelihood of success for each treatment method in each subpopulation. Furthermore, some patients may need to return to work promptly, which ultimately may influence their desired treatment method.

CONCLUSIONS

Currently, there is no universal treatment algorithm for TF. From a purely financial standpoint, women without diabetes presenting with a single triggering thumb should attempt 2 corticosteroid trials before percutaneous release. It is the most cost-effective for all other subpopulations to elect for immediate percutaneous release.

Trigger finger: An overview of the treatment options

Stenosing flexor tenosynovitis, more commonly known as trigger finger, is one of the most common causes of hand pain and dysfunction. Clinicians must be able to identify the disorder, know the broad range of treatment options, and counsel patients on the treatment best suited for their condition. Awareness of the economic burden each option entails is central to optimizing treatment outcomes and patient satisfaction.

Minimally invasive thread trigger digit release: a preliminary report on 34 digits of the adult hands

The trigger finger release was performed in 34 digits (11 thumbs and 23 fingers) of 24 patients through the thread transecting technique with the tip-to-tip approach, in which a 22-gauge needle inserts into a 18-gauge needle when both needles are inside the hand, guiding the 22-gauge needle to exit the hand at the same access point of 18-gauge needle. We prospectively evaluated the effectiveness and functional recovery of these patients. In all 34 digits, triggering and locking were resolved, and complete extension and flexion occurred immediately following the release. There were no complications, such as incomplete release, neurovascular or flexor tendon or A2 pulley injury, infection, or tendon bow-stringing. Patients did not require prescription pain medications. Most patients used their hands to meet their basic living needs the same day of the procedure. The hand function evaluated with the Quick Disabilities of the Arm, Shoulder and Hand questionnaire, and scored 4 within 3 months. Level of evidence: II.

Comparative clinical study of ultrasound-guided A1 pulley release vs open surgical intervention in the treatment of trigger finger

AIM

To investigate the effectiveness of ultrasound-guided release of the first annular pulley and compare results with the conventional open operative technique.

METHODS

In this prospective randomized, single-center, clinical study, 32 patients with trigger finger or trigger thumb, grade II-IV according to Green classification system, were recruited. Two groups were formed; Group A (16 patients) was treated with an ultrasound-guided percutaneous release of the affected A1 pulley under local anesthesia. Group B (16 patients) underwent an open surgical release of the A1 pulley, through a 10-15 mm incision. Patients were assessed pre- and postoperatively (follow-up: 2, 4 and 12 wk) by physicians blinded to the procedures. Treatment of triggering (primary variable of interest) was expressed as the “success rate” per digit. The time for taking postoperative pain killers, range of motion recovery, QuickDASH test scores (Greek version), return to normal activities (including work), complications and cosmetic results were assessed.

RESULTS

The success rate in group A was 93.75% (15/16) and in group B 100% (16/16). Mean times in group A patients were 3.5 d for taking pain killers, 4.1 d for returning to normal activities, and 7.2 and 3.9 d for complete extension and flexion recovery, respectively. Mean QuickDASH scores in group A were 45.5 preoperatively and, 7.5, 0.5 and 0 after 2, 4, and 12 wk postoperatively. Mean times in group B patients were 2.9 d for taking pain killers, 17.8 d for returning to normal activities, and 5.6 and 3 d for complete extension and flexion recovery. Mean QuickDASH scores in group B were 43.2 preoperatively and, 8.2, 1.3 and 0 after 2, 4, and 12 wk postoperatively. The cosmetic results found excellent or good in 87.5% (14/16) of group A patients, while in 56.25% (9/16) of group B patients were evaluated as fair or poor.

CONCLUSION

Treatment of the trigger finger using ultrasonography resulted in fewer absence of work days, and better cosmetic results, in comparison with the open surgery technique. It is a promising method that represents excellent results without major complications, so that it could be possibly be established as a first-line treatment in the trigger finger’s disease.

High-resolution ultrasound in the diagnosis of trigger finger and evaluation of response to steroid injection

OBJECTIVE

No studies have reported the use of ultrasound for the evaluation of trigger finger after steroid injection. We evaluated the clinical features and ultrasound appearance of trigger finger before and after steroid injection under ultrasound guidance.

MATERIALS AND METHODS

Thirty-eight digits with triggering were included. A single steroid injection into the tendon sheath was administered. Ultrasound findings and clinical symptoms, including pain, triggering, and the Quinnell score, were analyzed before injection and at 1 and 3 weeks after injection.

RESULTS

Ultrasound indicated that the thickness of the flexor tendons and the thickness of A1 pulleys were significantly greater in the trigger fingers than in controls before steroid injection. Three weeks after injection, these two parameters decreased, and there was no significant difference in the two parameters between the trigger finger and the controls. The visual analogue scales at 1 and 3 weeks after the injection were significantly lower than those before the injection. The Quinnell grading system scores significantly improved at 1 and 3 weeks after injection compared with the scores before injection. Moreover, a tendency was seen for the more clinically severe cases to show more swelling of the tendon and pulley.

CONCLUSION

In conclusion, ultrasound assessments could reveal that the thickened A1 pulley and flexor tendon significantly improved after steroid injection, which enables us to confirm the therapeutic effects of the steroid injection. Therefore, ultrasound assessments can be a useful adjunct to understand the response to treatment with the steroid injection.