Sonographic appearance of the flexor tendon, volar plate, and A1 pulley with respect to the severity of trigger finger

Diagnostic and Interventional US of the Wrist and Hand: Quadrant-based Approach

Diagnostic and interventional US of the wrist and hand can be challenging due to the small size and superficial location of structures and various disorders that need to be considered. A quadrant-based approach (volar, ulnar, dorsal, and radial) provides a rational method for performing a focused examination and joint positioning during both diagnostic imaging and intervention. Volar wrist disorders primarily involve the median nerve and the digital flexor system comprised of the flexor tendons and pulleys. The ulnar nerve and extensor carpi ulnaris tendon are chiefly responsible for ulnar-sided wrist pain. The differential diagnosis for dorsal-sided symptoms typically involves the extensor tendon compartments and includes distal intersection syndrome, extensor pollicis longus tear, and digital extensor apparatus injury. The soft-tissue ganglion is the most common abnormality in the dorsal wrist, typically associated with wrist ligaments or joint capsule. Radial-sided pain may be secondary to de Quervain tenosynovitis and must be differentiated from the more proximal intersection syndrome. US is an important tool for assessing the ulnar collateral ligament of the first metacarpophalangeal joint of the thumb and differentiating between displaced and nondisplaced tears, thereby influencing management. Despite the complexity of the anatomy and potential pathologic features within the wrist, a focused quadrant-based examination can permit the sonologist to focus on the structures of relevance. In conjunction with a systematic approach, this can aid in precise and efficient diagnostic scanning and intervention of the wrist and hand. ©RSNA, 2023 Supplemental material is available for this article. Quiz questions for this article are available through the Online Learning Center.

The cross-sectional area ratio of a specific part of the flexor pollicis longus tendon- a stable sonographic measurement for trigger thumb: a cross-sectional trial

BACKGROUND

Trigger thumb is a pathologic condition of the digital pulleys and flexor tendons. To find a cutoff value of the cross-sectional area ratio of specific parts of the flexor pollicis longus tendon to diagnosis trigger thumb in the high-frequency ultrasound examination.

METHODS

We evaluated 271 healthy volunteers and 57 patients with clinical diagnosis of trigger thumb. The cross-sectional area of the metacarpophalangeal joint of flexor pollicis longus tendon (C1) and the cross-sectional area of the midpoint of the first metacarpal of flexor pollicis longus tendon (C2) were analyzed.

RESULTS

There is no difference between gender, age and left and right hands in the ratio of C1 to C2 (C1/ C2). The mean of C1/ C2 in the healthy thumb was 0.983 ± 0.103, which was significantly smaller in comparison to the diseased thumb (P < 0.05). Based on the receiver operating characteristic curve, we chose the diagnostic cut-off value for the C1/ C2 to be 1.362 and 1.153 in order to differ a trigger thumb from children and adults.

CONCLUSIONS

The C1/ C2 of the healthy thumb was relatively stable, with a mean value of 0.983 ± 0.103. The cutoff value of C1/C2 to distinguish healthy thumb from diseased thumb in children and adults were 1.362 and 1.153, respectively.

Symptom Duration and Diabetic Control Influence Success of Steroid Injection in Trigger Finger

BACKGROUND

Trigger finger is one of the most common hand pathologies, with a prevalence in 2% of the general population. Conservative treatment with corticosteroid injections at the A1 pulley has been shown to be a cost-effective first line treatment. However, additional patient factors have not fully been described regarding steroid injection efficacy. We hypothesize that patients presenting with longer chronicity of symptoms prior to treatment and elevated blood sugars would have reduced success rates of steroid injection therapy.

METHODS

A retrospective chart review of 297 patients at a single institution was performed between years 2013-2019. Patients were included if they presented with the diagnosis trigger finger and were treated with initial corticosteroid injection at the A1 pulley.

RESULTS

Steroid injection therapy alone was successful in 65% of patients. Patients received on average 1.61 steroid injections. Patients who failed treatment received an average of 1.85 injections compared to 1.49 for those who had successful corticosteroid injection therapy (p=0.001). Presence of ipsilateral hand disease was associated with significant increase in failure of steroid injections (43.4% versus 30.8%, p=0.032). Diabetic patients with Hemoglobin A1c> 6.5 had a significantly higher rate of failing steroid injection therapy (71.9% versus 38.1%, p<0.001). Patients that presented with greater than 2.5 months of symptoms had a higher failure rate of corticosteroid therapy (40.4% versus 29.5%, p=0.048).

CONCLUSIONS

Patients with a co-existing diagnosis of diabetes and an A1c greater than 6.5, ipsilateral concomitant hand disease, or presence of symptoms for greater than 2.5 months should be counseled regarding higher risk of failure of local corticosteroid injection.

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

»

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.

»

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.

»

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.

»

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.

»

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.

Evaluation of the first annular pulley stretch effect under isometric contraction of the flexor tendon in healthy volunteers and trigger finger patients using ultrasonography

Background

Isometric exercises for a flexed finger have been reported to be effective for treating trigger finger as the flexor tendon widens the space under the first annular (A1) pulley towards the palmar destination during the exercise. This study aimed to evaluate the structural changes during the A1 pulley stretch in healthy volunteers and patients with trigger finger using ultrasonography.

Methods

We enrolled 25 male and 14 female patients (39 middle fingers). The thickness of the subcutaneous tissue (parameter a), A1 pulley (parameter b), and the flexor tendon (parameter c) and the distance between the dorsal surface of the flexor tendon and the palmar surface of the metacarpal head (parameter d) were measured using ultrasonography of the metacarpophalangeal joint of the middle finger flexed at 45° at rest (pattern A) and under isometric contraction of the flexor tendon against an extension force of the proximal interphalangeal joint (pattern B).

Results

The average differences between patterns A and B in the healthy volunteers were 0.29 mm (parameter a; P = 0.02), 0.017 mm (parameter b; P = 0.63), 0.16 (parameter c; P = 0.26), and 0.41 (parameter d; P = 0.004), and those in patients with trigger finger were 0.22 mm (parameter a; P = 0.23), 0.019 mm (parameter b; P = 0.85), 0.03 mm (parameter c; P = 0.82), and 0.78 mm (parameter d; P < 0.001). The distance between the dorsal side of the A1 pulley and the palmar surface of the metacarpal head was also significantly increased by 0.57 mm (8.2%) in healthy volunteers (P < 0.001) and 0.81 mm (11%) in patients with trigger finger (P < 0.001).

Conclusions

In this study, the space under the A1 pulley was expanded under isometric contraction of the flexor tendon. These findings support the effectiveness of pulley stretch exercises for the trigger finger condition.

A1 pulley stretching treats trigger finger: A1 pulley luminal region under digital flexor tendon traction

BACKGROUND

A1 pulley stretching is recognized as a clinically beneficial treatment for trigger finger. It is thought to lead to an increase in the cross-sectional area of the A1 pulley luminal region, thus improving trigger finger symptoms. The purpose of the present study was thus to evaluate the resultant forces during stretching that increase the CSA of the A1 pulley luminal region using fresh-frozen cadavers.

METHODS

Using seven fingers from three fresh-frozen cadavers to replicate A1 pulley stretching, we investigated the resultant forces during stretching that increase the cross-sectional area of the A1 pulley luminal region. The traction forces of the flexor digitorum profundus tendons were increased in steps to 150 N, and the cross-sectional area and height of the A1 pulley luminal region were measured using ultrasonography.

FINDINGS

The cross-sectional area of the A1 pulley luminal region increased with step-wise increases in the flexor digitorum profundus traction. On average, the cross-sectional area and height of the A1 pulley luminal region showed increases of 31.4% and 43.6%, respectively, compared to the unloaded condition.

INTERPRETATION

These results confirmed that A1 pulley stretching increases the cross-sectional area of the A1 pulley luminal region. A1 pulley stretching has the potential to reduce the severity of trigger finger in patients facing surgery.

Characterization of Hand Tendons Through High-Frequency Ultrasound Elastography

Tendon stiffness plays an important role in the tendon healing process, and many studies have indicated that measuring the shear wave velocity (SWV) on tendons relates to their stiffness. Because the thickness of hand tendons is a few millimeters, high-resolution imaging is required for visualizing hand tissues. However, the resolution of current ultrasound elastography systems is insufficient. In this study, a high-frequency (HF) ultrasound elastography system is proposed for measuring the SWVs of hand tendons. The HF ultrasound elastography system uses an external vibrator to create shear waves on hand tendons. Then, it uses a 40-MHz HF ultrasound array transducer with ultrafast ultrasound imaging technology to measure the SWV for characterizing hand tendons. A handheld device that combines a transducer and a vibrator allows the user to scan hand tissues. The biases of HF ultrasound elastography were measured in gelatin phantom experiments and were less than 6% compared to standard mechanical testing approach. Human experiments showed the ability to use HF ultrasound elastography to distinguish different SWVs of hand tendons. The SWVs were 0.73 ± 0.65 m/s and 1 ± 0.54 m/s for flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP), respectively, and 0.52 ± 0.14 m/s and 4.02 ± 0.77 m/s for extensor tendon under stretch and contraction conditions, respectively. The simplicity and convenience of the HF ultrasound elastography system for measuring hand tendon stiffness make it a promising tool for evaluating the severity of hand injuries and the performance of rehabilitation after hand injuries.

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.

Correlation between Hypervascularization of the First Annular Pulley on Color Doppler Imaging of Trigger Finger and Patients' Backgrounds

OBJECTIVES

The aim of this study was to investigate the correlation between hypervascularization of the first annular (A1) pulley on color Doppler imaging of trigger finger and patients' backgrounds.

METHODS

A total of 148 trigger digits from 144 patients were studied with ultrasound at the time of initial diagnosis. We observed the A1 pulley at the level of the metacarpophalangeal joint in a transverse image and noted the presence or absence of a signal in the A1 pulley on color Doppler imaging. Patients' ages, sexes, clinical grades, symptom durations, prevalence of interphalangeal joint contracture, and visual analog scale pain scores were compared between the groups with positive and negative Doppler findings.

RESULTS

The 144 patients included 45 men and 99 women. Sixty-one of 148 digits (41%) showed positive Doppler findings in the A1 pulley. Patients' ages and visual analog scale scores in the Doppler-positive group were slightly greater than those in the Doppler-negative group (P = .03; P < .01, respectively). The digit with positive Doppler findings tended to be categorized into a severer grade and into the group with a shorter symptom duration (P < .01 for both).

CONCLUSIONS

Hypervascularization of the A1 pulley tended to appear in an earlier period after the patients had become aware of symptoms, as frequently as their symptoms became severe, in conjunction with higher pain scores. Doppler imaging of the A1 pulley might help in better understanding patients' conditions.

Ultrasonographic Features of Trigger Finger in Patients With Hyperuricemia

PURPOSE

The purpose of the current study was to compare demographic differences and ultrasonographic features in primary trigger finger and trigger finger in association with hyperuricemia.

METHODS

Between October 2008 and February 2010, a prospective review of consecutive cases of 54 patients with trigger finger and hyperuricemia, 76 patients with a trigger finger without hyperuricemia, and 80 control cases were enrolled. The clinical results were analyzed by descriptive epidemiology, an ultrasonographic measurement of the thickness of A1 pulley, cross-sectional area of the flexor tendon and synovium.

RESULTS

The middle finger was primarily affected, followed by the index and ring fingers in both trigger finger groups. The thickness of A1 pulley, cross-sectional area of the flexor tendon, and flexor tendon with synovium in trigger finger without hyperuricemia group were significantly larger than that in trigger finger with hyperuricemia and control groups. There was no significant difference between trigger finger with hyperuricemia and control groups. Double-contour sign and tophus were only observed in trigger finger with hyperuricemia group.

CONCLUSIONS

Thickness of A1 pulley, cross-sectional area of the flexor tendon, and flexor tendon with synovium were significantly larger in trigger finger without hyperuricemia group. These findings were not evident in trigger finger with hyperuricemia group.

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.

The thickening of flexor tendons pulleys: a useful ultrasonographical sign in the diagnosis of psoriatic arthritis

PURPOSE

To investigate the frequency of thickening of pulleys for flexor tendons in patients with early arthritis in their hands, and to evaluate it as a predictive sign of PsA.

METHODS

A prospective observational study involving 228 consecutive patients presenting with recent onset of arthritis in their hands was conducted at rheumatology outpatient clinics in the Veneto region of Italy between October 2014 and September 2017. Diabetic patients were excluded because of the high frequency of trigger finger. The final diagnosis of the rheumatologist delivered after 12 months of follow-up, was considered as the gold standard for the analysis of diagnostic accuracy.

RESULTS

Twenty-two patients were excluded from the study because of diabetes. A total of 86 patients with thickening of A1 pulleys in flexor tendons and 120 without were evaluated. Pulley thickness was significantly associated with a family history of psoriasis (18/86 vs 3/120, p ˂ 0.001) and diabetes (9/86 vs 4/120, p = 0.036), and with a personal history of cutaneous psoriasis (25/86 vs 10/120, p ˂ 0.001), psoriatic onychopathy (7/86 vs 2/120, p = 0.028), lower back pain (22/86 vs 11/120, p = 0.001), Dupuytren's disease (7/86 vs 2/120 p = 0.028) and De Quervain tenosynovitis (4/86 vs 0/120, p = 0.028). In isolation, this sign had a good sensitivity rate (80%). The specificity rate for the disease was barely significative (71%), with an LR+ of 2.71 for PsA.

CONCLUSIONS

The thickening of the pulleys in the flexor tendons is an easy-to-detect sign with good sensitivity for the diagnosis of PsA. Its specificity and positive predictive value are not very high; however, if it is included in a complete classification process, sonographers should report it during hand evaluations of patients with arthritis.

Comprehensive simulation on morphological and mechanical properties of trigger finger - A cadaveric model

Trigger finger has long been a common disorder in hand orthopedics. To clarify the unknown causative factors regarding the disease, numerous experiments were done on human cadavers, including tendon forces, tendon moment arm, mechanical properties of the pulley, gliding resistance, etc. However, most of these studies were conducted on normal fingers. As the etiology of trigger finger is still controversial on whether it is an outcome of tendon nodule or pulley scarring, in this study, a trigger finger model was built combining both the nodule created by silicone gel injection and pulley constriction by external compression. Indentation and gliding resistance tests were performed on cadaveric specimens to verify the model. Results showed that after silicone gel injection into the tendon, a significant increase in thickness was found. In addition, no significant difference was found in the toe region compressive modulus of the tendon after injection. Moreover, maximum, drop of gliding resistance and work of extension were all found to be significantly larger as the severity of triggering increased. Our results indicated we have developed a feasible cadaver model simulating trigger finger nodule which could be utilized for further experiments to elucidate other causative factors and biomechanical features of trigger finger in the future.

Sonography of Non-neoplastic Disorders of the Hand and Wrist Tendons

Tendon disorders commonly cause hand and wrist disability and curtail the performance of work-related duties or routine tasks. Imaging is often needed for diagnosis, but it requires knowledge of the complex anatomic structures of the tendons of the hand and wrist as well as familiarity with related disorders. This review article aims to provide medical professionals with guidelines for the sonographic assessment of the tendons of hand and wrist and related disorders. Sonographic features of tendon disorders affecting the hand and wrist are described here, specifically: infectious tenosynovitis; tendon rupture or tearing; stenosing forms of tenosynovitis such as De Quervain disease and trigger finger; intersection syndrome; insertional tendinopathy; several forms of tendinous instability such as extensor carpi ulnaris instability, climber finger, and boxer knuckle; and tendinopathy in inflammatory rheumatic diseases. Postsurgical evaluation of the hand and wrist tendons is also discussed, including the healthy and pathologic appearances of operated tendons as well as impingement from orthopedic hardware. In conclusion, sonography is effective in assessing the tendons of the hand and wrist and related disorders and represents a valuable tool for diagnosis.

A medical imaging analysis system for trigger finger using an adaptive texture-based active shape model (ATASM) in ultrasound images

Trigger finger has become a prevalent disease that greatly affects occupational activity and daily life. Ultrasound imaging is commonly used for the clinical diagnosis of trigger finger severity. Due to image property variations, traditional methods cannot effectively segment the finger joint’s tendon structure. In this study, an adaptive texture-based active shape model method is used for segmenting the tendon and synovial sheath. Adapted weights are applied in the segmentation process to adjust the contribution of energy terms depending on image characteristics at different positions. The pathology is then determined according to the wavelet and co-occurrence texture features of the segmented tendon area. In the experiments, the segmentation results have fewer errors, with respect to the ground truth, than contours drawn by regular users. The mean values of the absolute segmentation difference of the tendon and synovial sheath are 3.14 and 4.54 pixels, respectively. The average accuracy of pathological determination is 87.14%. The segmentation results are all acceptable in data of both clear and fuzzy boundary cases in 74 images. And the symptom classifications of 42 cases are also a good reference for diagnosis according to the expert clinicians’ opinions.

Morphological alterations of the tendon and pulley on ultrasound after intrasynovial injection of betamethasone for trigger digit

Purpose

The aim of this study was to elucidate whether intrasynovial corticosteroid injections for trigger digit reduced the volume of the tendon and pulley on high-resolution ultrasonography.

Methods

Twenty-three digits of 20 patients with trigger digit were included. Each affected finger was graded clinically according to the following classification: grade I for pre-triggering, grade II for active triggering, grade III for passive triggering, and grade IV for presence of contracture. Axial ultrasound examinations were performed before an intrasynovial corticosteroid injection and at an average of 31 days after the injection. The transverse diameter, thickness, and cross-sectional area of the tendon and the thickness of the pulley were measured by two independent, blinded researchers.

Results

At least 1 grade of improvement was achieved in this study group by the time of the second examination. The transverse diameter and cross-sectional area of the tendon and the thickness of the pulley significantly decreased (P<0.05).

Conclusion

The injection of a single dose of betamethasone improved clinical symptoms by reducing the volume of both the tendon and pulley, which may be related to the fact that tendon and pulley ruptures are delayed by corticosteroid injections.

What triggers in trigger finger? The flexor tendons at the flexor digitorum superficialis bifurcation

To define the role of the flexor tendons in trigger finger, a high-resolution ultrasound examination was performed in 20 trigger fingers and 20 normal contralateral digits in three digital postures: full extension, mid-flexion and near-full flexion. Precise measurements of diameter and cross-sectional area of the combined tendon mass were recorded at five clearly defined locations: summit of the metacarpal head, proximal lip of the proximal phalanx (PP) and at 1/8, 1/4 and 1/2 length of the PP. In the normal tendons, there was an anatomical thickening, not previously appreciated at 1/4 length PP, in the region of the FDS bifurcation. This anatomical region moved proximally on finger flexion to the A1 pulley. In trigger fingers, the flexor tendons had greater diameter (sagittal view) and cross-sectional area than the normal side at all locations (p < 0.01, p < 0.001), with an even greater increase in diameter in the FDS bifurcation area (p < 0.001). Trigger fingers also had thicker A1 pulleys (p < 0.001). Triggering occurs on flexing the finger when the enlarged combined flexor tendon mass at the specific anatomical region of the FDS bifurcation impacts on the thickened A1 pulley, resisting its excursion.

Quantitative Assessment of First Annular Pulley and Adjacent Tissues Using High-Frequency Ultrasound

Due to a lack of appropriate image resolution, most ultrasound scanners are unable to sensitively discern the pulley tissues. To extensively investigate the properties of the A1 pulley system and the surrounding tissues for assessing trigger finger, a 30 MHz ultrasound system was implemented to perform in vitro experiments using the hypodermis, A1 pulley, and superficial digital flexor tendon (SDFT) dissected from cadavers. Ultrasound signals were acquired from both the transverse and sagittal planes of each tissue sample. The quantitative ultrasonic parameters, including sound speed, attenuation coefficient, integrated backscatter (IB) and Nakagami parameter (m), were subsequently estimated to characterize the tissue properties. The results demonstrated that the acquired ultrasound images have high resolution and are able to sufficiently differentiate the variations of tissue textures. Moreover, the attenuation slope of the hypodermis is larger than those of the A1 pulley and SDFT. The IB of A1 pulley is about the same as that of the hypodermis, and is very different from SDFT. The m parameter of the A1 pulley is also very different from those of hypodermis and SDFT. This study demonstrated that high-frequency ultrasound images in conjunction with ultrasonic parameters are capable of characterizing the A1 pulley system and surrounding tissues.

Correlation Between Sonographic and In Vivo Measurement of A1 Pulleys in Trigger Fingers

The thickness of 210 A1 pulleys of 21 male and female healthy volunteers in two different age groups (20-35 y and 50-70 y) were measured by ultrasound. In a second group, the thickness of 15 diseased A1 pulleys and 15 A1 pulleys of the corresponding other hand of 10 patients with the clinical diagnosis of trigger finger were measured by ultrasound. During open trigger finger release, a strip of A1 pulley was excised and immediately measured using an electronic caliper. The average pulley thickness of healthy volunteers was 0.43-0.47 mm, compared to 0.77-0.79 mm in patients with trigger finger. Based on the receiver operating characteristic (ROC) curve, a diagnostic cut-off value of the pulley thickness at 0.62 mm was defined in order to differ a trigger finger from a healthy finger (sensitivity and specificity of 85%). The correlation between sonographic and effective intra-operative measurements of pulley thickness was linear and very strong (Pearson coefficient 0.86-0.90). In order to distinguish between healthy and diseased A1 pulleys, 0.62 mm is a simple value to use, which can be applied regardless of age, sex, body mass index (BMI) and height in adults.

Ultrasound-Guided Interventional Procedures of the Wrist and Hand: Anatomy, Indications, and Techniques

Acute and chronic wrist and hand conditions are commonly seen by neuromuscular and musculoskeletal specialists. High-frequency diagnostic ultrasonography (US) has facilitated advances in the diagnosis and interventional management of wrist and hand disorders. US provides excellent soft tissue resolution, accessibility, portability, lack of ionizing radiation, and the ability to dynamically assess disorders and precisely guide interventional procedures. This article review the relevant anatomy, indications, and interventional techniques for common disorders of the wrist and hand, including radiocarpal joint arthritis, scaphotrapeziotrapezoidal joint arthritis, trapeziometacarpal joint arthritis, phalangeal joint arthritis, first dorsal compartment tenosynovitis, ganglion cysts, and stenosing tenosynovitis.

Comparison of the Thickness of Pulley and Flexor Tendon Between in Neutral and in Flexed Positions of Trigger Finger

Objective:

This study aims to compare the morphology of the A1 pulley and flexor tendons in idiopathic trigger finger of digits other than the thumb between in neutral position and in the position with the interphalangeal joints full flexed and with the metacarpophalangeal (MP) joint 0° extended (hook grip position).

Method:

A total of 48 affected digits and 48 contralateral normal digits from 48 patients who initially diagnosed with idiopathic trigger finger were studied sonographically. Sonographic analysis was focused on the A1 pulley and flexor tendons at the level of the MP joint in the transverse plane. We measured the anterior-posterior thickness of A1 pulley and the sum of the flexor digitorum superficialis and profundus tendons, and also measured the maximum radialulnar width of the flexor tendon in neutral and hook grip positions, respectively. Each measurement was compared between in neutral and in hook grip positions, and also between the affected and contralateral normal digits in each position.

Results:

In all the digits, the anterior-posterior thickness of flexor tendons significantly increased in hook grip position as compared with in neutral position, whereas radial-ulnar width significantly decreased. Both the A1 pulley and flexor tendons were thicker in the affected digits as compared with contralateral normal digits.

Conclusion:

The thickness of flexor tendons was significantly increased anteroposteriorly in hook grip position as compared with in neutral position. In trigger finger, A1 pulley and flexor tendon were thickened, and mismatch between the volume of the flexor tendon sheath and the tendons, especially in anterior-posterior direction, might be a cause of repetitive triggering.

Comparative study on the effectiveness of corticosteroid injections between trigger fingers with and without proximal interphalangeal joint flexion contracture

Trigger fingers with proximal interphalangeal joint flexion contracture are suggested to have a poorer response to corticosteroid injection than those without contracture, though this has not been proven scientifically. We compared the clinical response to corticosteroid injection between trigger fingers with and without proximal interphalangeal joint contracture, and investigated the influence of the injection on the A1 pulley and flexor digitorum tendons using ultrasonography. One month after injection, pain was significantly reduced in the no contracture group, and 56% of trigger fingers with proximal interphalangeal joint contracture resolved. Before injection, relative thickening of the A1 pulley and flexor digitorum tendons, and a partial hypoechoic lesion of the flexor digitorum superficialis tendon were observed in the contracture group. One month after injection, the thickening of the tendons and the A1 pulley was reduced, but the partial hypoechoic lesion was still observed in significant numbers. We have demonstrated that the presence of a proximal interphalangeal joint contracture was associated with a reduced clinical response to corticosteroid injection, and we suggest that the pathologic change in the flexor digitorum superficialis tendon, represented by the partial hypoechoic lesion, contributed to corticosteroid injection resistance.

LEVEL OF EVIDENCE

IV.

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

We aimed to investigate the relationship between the pulley-tendon complexes and the severity of trigger finger. The thickness of the A1 and A2 pulleys, and the cross-sectional area of the flexor tendon under the pulleys, were prospectively assessed using 17 MHz high-resolution ultrasonography, in 20 patients with trigger finger (31 fingers). A control group comprised 15 asymptomatic fingers. The thickness of the A1 pulley and the proximal part of the A2 pulley, and the cross-sectional area of the flexor tendon under the A2 pulley, were significantly increased in the patient group. Clinical grade was significantly correlated with the thickness of the A1 pulley, the thickness of the proximal part of the A2 pulley, and the cross-sectional area of the flexor tendon under the proximal part of the A2 pulley. This study confirmed that the thickness of the A2 pulley and flexor tendon under the A2 pulley seems to be related to the severity of trigger finger.

LEVEL OF EVIDENCES

Level III.

Sonographic evaluation of effects of the volar plate on trigger finger

BACKGROUND

We evaluated trigger fingers ultrasonographically and clarified differences between fingers with and without continuous locking or snapping symptoms according to the thicknesses of the A1 pulley, flexor tendon and volar plate.

METHODS

We evaluated 26 trigger fingers, divided into two groups: Group 1, 14 fingers with locking or snapping; and Group 2, 12 fingers without such symptoms. We also evaluated 26 contralateral fingers as controls (Control 1 and 2 groups). We compared each group to the respective control group according to thickness of the A1 pulley and volar plate, and cross-sectional area of the flexor tendon. In addition, nine fingers with locking or snapping and treated using corticosteroid injection were evaluated according to symptoms and sonographic findings 3-4 weeks after treatment.

RESULTS

Thickness of the A1 pulley and cross-sectional area of the flexor tendon were greater in both Groups 1 and 2 than in controls. Thickness of the volar plate was greater in Group 1 than in Control 1, although no significant difference was seen between Group 2 and Control 2. In Group 1, eight of the nine fingers showed an alleviation of locking or snapping symptoms with corticosteroid injection, and sonographic findings showed that thickness of the volar plate was significantly decreased with corticosteroid injection, in addition to reduced thickness of the A1 pulley.

CONCLUSION

In addition to thickening of the A1 pulley, thickening of the volar plate may represent an important contributor to continuous snapping or locking symptoms.

Considerations in the Radiologic Evaluation of the Pregnant Orthopaedic Patient

Radiographic imaging of the pregnant patient represents a diagnostic and management dilemma for the orthopaedic surgeon. Imaging is often necessary in the setting of trauma; however, in utero radiation exposure can result in deleterious developmental effects in the embryo and fetus. The likelihood of a negative effect is proportional to the radiation dose and the gestational age of the embryo or fetus at the time of exposure. Ionizing radiation doses >100 mGy in the first trimester of pregnancy may lead to spontaneous abortion, malformation, and mental retardation. Whereas plain radiographs of the extremities and cervical spine expose the fetus to minimal doses of radiation of <10 mGy, other commonly performed orthopaedic diagnostic studies, such as CT of the pelvis, emit significantly higher exposure doses of approximately 35 mGy. Non-emitting modalities, such as ultrasonography and MRI, are alternatives for evaluation in the clinical setting.

Role of sonographic imaging in occupational therapy practice

Occupational therapy practice is grounded in the delivery of occupation-centered, patient-driven treatments that engage clients in the process of doing to improve health. As emerging technologies, such as medical imaging, find their way into rehabilitation practice, it is imperative that occupational therapy practitioners assess whether and how these tools can be incorporated into treatment regimens that are dually responsive to the medical model of health care and to the profession's foundation in occupation. Most medical imaging modalities have a discrete place in occupation-based intervention as outcome measures or for patient education; however, sonographic imaging has the potential to blend multiple occupational therapy practice forms to document treatment outcomes, inform clinical reasoning, and facilitate improved functional performance when used as an accessory tool in direct intervention. Use of medical imaging is discussed as it relates to occupational foundations and the professional role within the context of providing efficient, effective patient-centered rehabilitative care.

Sonographic analyses of pulley and flexor tendon in idiopathic trigger finger with interphalangeal joint contracture

This study investigated the sonographic appearance of the pulley and flexor tendon in idiopathic trigger finger in correlation with the contracture of the interphalangeal (IP) joint in the thumb or proximal IP (PIP) joint in the other digits. Sonographic measurements using axial images were performed in 177 affected digits including 17 thumbs and 34 other digits judged to have IP or PIP joint contracture and 77 contralateral control digits. The A1 pulley of the contracture group was significantly thicker than that of the non-contracture group in all digits, whereas the flexor tendon was thicker only in digits other than the thumb. In the analysis using calculated cut-off values, A1 pulley thickening in the thumb and A1 pulley and flexor tendon thickening in the other digits showed statistically significant correlations with IP or PIP joint contracture. This study sonographically confirmed previous reports showing that enlargement of the flexor tendons contribute to the pathogenesis of PIP joint contracture.

Small longitudinal S incision and page turning style of annular ligament partial resection to treat stenosing tenosynovitis of thumb flexor tendon

Background

To present the treatment outcome for patients with stenosing tenosynovitis of thumb flexor tendon treated with a small S incision and page turning style of annular ligament partial resection.

Material/Methods

During a 2-year period between August 2011 and July 2013, 12 consecutive patients (mean age, 45.8 years) with stenosing tenosynovitis of the thumb flexor tendon were prospectively enrolled into this study. All 12 patients underwent longitudinal S skin incision to expose annular ligament and thumb flexor tendon, and with page turning style of annular ligament partial resection to finish the operation. The average range of motion of metacarpophalangeal thumb joint, Quick disability of arm, shoulder, and hand and Short Musculoskeletal Function Assessment Dysfunction score of arm and hand were primary outcome measures.

Results

There were 9 cases of stiff metacarpophalangeal joint of thumb and 3 cases of snapping thumb for stenosing tenosynovitis. At 1-year follow-up, all stenosing tenosynovitis had healed by an average of 4 weeks. The average range of motion of the metacarpophalangeal joint was 37.1° (range, 34–40°). No patients had recurrence, cicatricial contraction, or postoperative infection. The average disability of arm, shoulder, and hand was 0.3 out of 100 (range, 0–1.67), and average Short Musculoskeletal Functional Assessment Dysfunction score of arm and hand was 6.9 out of 40 (range, 0–15.6). All 12 patients stated that they were highly satisfied.

Conclusions

Small S incision and page turning style of annular ligament partial resection for stenosing tenosynovitis of thumb flexor tendon is a safe, simple, and reliable alternative treatment with minimal soft-tissue irritation, good functional results and recovery can be expected.