Pediatric Trigger Thumb with Metacarpophalangeal Joint Hyperextension or Instability.

BACKGROUND The aim of this study was to provide the first on report on the mechanism and the different treatment measures of metacarpophalangeal joint hyperextension (MCPH) or metacarpophalangeal joint instability (MCPI) in cases of pediatric trigger thumb. Some pediatric trigger thumb patients have disease combined with excessive extension of metacarpophalangeal (MCP) joint or instability of MCP joint. MATERIAL AND METHODS A total of 1083 children with trigger thumb surgery were divided into 2 groups (the MCPH group and the MCPI group) by the extension degree of the MCP joint. After tendon sheath released, the MCPH group was treated by a cast and the MCPI group was treated by a cast and a brace. We compared the differences in baseline data and the further functional activities of interphalangeal (IP) and MCP joint between the 2 groups. RESULTS Among the 1083 cases, 154 cases (185 thumbs) were trigger thumb with MCPH or MCPI, of which 167 thumbs were placed in the MCPH group and 18 thumbs were placed in the MCPI group. The average age of the MCPH group was 2.8 years, with an average duration of disease of 13 months. The average age of the MCPI group was 6.6 years, with an average duration of disease of 33 months. MCPH still existed after cast removal. In the MCPI group, 12 out of 18 thumbs recovered; 6 thumbs relapsed at 2-4 months after brace removal. CONCLUSIONS Trigger thumb with MCPH and MCPI in children is significantly associated with multi-joint laxity. While there was still MCPH after cast treatment, there was no need for further treatment during the short-term follow-up. Cast and brace treatment after surgery was a simple, easy method for treatment of MCPI and had a good effect.

MR imaging findings of trigger thumb.

Trigger finger (or trigger thumb), also known as sclerosing tenosynovitis, is a common clinical diagnosis that rarely presents for imaging. Because of this selection bias, many radiologists may not be familiar with the process. Furthermore, patients who do present for imaging frequently have misleading examination indications. To our knowledge, magnetic resonance (MR) imaging findings of trigger thumb have not been previously reported in the literature. In this article, we review the entity of trigger thumb, the anatomy involved, and associated imaging findings, which include flexor pollicis longus tendinosis with a distinct nodule, A1 pulley thickening, and tenosynovitis. In addition, in some cases, an abnormal Av pulley is apparent. In the rare cases of trigger finger that present for MR imaging, accurate diagnosis by the radiologist can allow initiation of treatment and avoid further unnecessary workup.

Clinical and pathological correlates of severity classifications in trigger fingers based on computer-aided image analysis.

BACKGROUND: The treatment of trigger finger so far has heavily relied on clinicians' evaluations for the severity of patients' symptoms and the functionality of affected fingers. However, there is still a lack of pathological evidence supporting the criteria of clinical evaluations. This study's aim was to correlate clinical classification and pathological changes for trigger finger based on the tissue abnormality observed from microscopic images. METHODS: Tissue samples were acquired, and microscopic images were randomly selected and then graded by three pathologists and two physicians, respectively. Moreover, the acquired images were automatically analyzed to derive two quantitative parameters, the size ratio of the abnormal tissue region and the number ratio of the abnormal nuclei, which can reflect tissue abnormality caused by trigger finger. A self-developed image analysis system was used to avoid human subjectivity during the quantification process. Finally, correlations between the quantitative image parameters, pathological grading, and clinical severity classification were assessed. RESULTS: One-way ANOVA tests revealed significant correlations between the image quantification and pathological grading as well as between the image quantification and clinical severity classification. The Cohen's kappa coefficient test also depicted good consistency between pathological grading and clinical severity classification. CONCLUSIONS: The criteria of clinical classification were found to be highly associated with the pathological changes of affected tissues. The correlations serve as explicit evidence supporting clinicians in making a treatment strategy of trigger finger. In addition, our proposed computer-aided image analysis system was considered to be a promising and objective approach to determining trigger finger severity at the microscopic level.

Histopathology of tenosynovium in trigger fingers.

Stenosing flexor tenosynovitis, trigger finger, is a common clinical disorder causing painful locking or contracture of the involved digits, and most instances are idiopathic. This problem is generally caused by a size mismatch between the swollen flexor tendon and the thickened first annular pulley. Although hypertrophic pulleys have been histologically and ultrasonographically detected, little is known about the histopathology of the tenosynovium covering the tendons of trigger fingers. We identified chondrocytoid cells that produced hyaluronic acid in 23 (61%) fingers and hypocellular collagen matrix in 32 (84%) fingers around the tenosynovium among 38 specimens of tenosynovium from patients with trigger fingers. These chondrocytoid cells expressed the synovial B cell marker CD44, but not the chondrocyte marker S-100 protein. The incidence of these findings was much higher than that of conventional findings of synovitis, such as inflammatory infiltrate (37%), increased vascularity (37%), hyperplasia of synovial lining cells (21%), or fibrin exudation (5%). We discovered the following distinctive histopathological features of trigger finger: hyaluronic acid-producing chondrocytoid cells originated from fibroblastic synovial B cells, and a hypocellular collagen matrix surrounding the tenosynovium. Thus, an edematous extracellular matrix with active hyaluronic acid synthesis might increase pressure under the pulley and contribute to the progression of stenosis.

Finger flexor rigidity in the healthy population.

The involvement of the hand flexors in trigger finger is not clear. This study aimed to examine the rigidity of the flexor tendon in the first pulley territory in the hand by using ultrasound in a healthy population, as well as to create a reference scale of rigidity for the flexor tendons to compare those values in trigger fingers. We tested 35 healthy volunteers using a linear ultrasound transducer and the color Doppler method. Rigidity levels below the first pulley were examined and compared between the different fingers of the hand and the relationship between rigidity and sex and the three different age groups was evaluated. In the healthy population, the rigidity of the flexor tendons of the hand in the territory of the first pulley varied between 233.1 and 962.8 kPa, with an average of 486.42 kPa and standard deviation of 114.85. We showed that the flexors in the dominant hand were more rigid, there was a difference between the rigidity of the flexor tendons of the thumb and the other fingers of the same hand, and the ring finger of the dominant hand had stiffer flexor tendons than the fingers of the other hand in the male population. We created a value scale for the rigidity of the flexor tendons of the fingers. This base scale can be compared between different pathologies, including trigger finger. The study and all experimental protocols were approved by the local ethical committee.

Epidemiology of carpal tunnel syndrome in patients with single versus multiple trigger digits.

PURPOSE: Previous studies have identified the association between trigger digit and carpal tunnel syndrome (CTS). However, whether the presence of multiple trigger digits affects the prevalence of CTS is unknown. The purpose of this study was to determine the incidence of carpal tunnel symptoms in patients treated for single versus multiple trigger digits. METHODS: We performed a retrospective review of 300 patients treated for trigger digit by injection or surgical release and recorded CTS symptoms, signs, and treatment for either the ipsilateral or contralateral hand documented within 24 months before trigger digit treatment and for an average of 35 months (range, 7- 66 mo) after treatment. Patients were categorized as having single (n = 160) or multiple (n = 140) trigger digits. Binary logistic regression modeled risk factors for development of CTS. Patient age, sex, number of trigger digits (single or multiple), and presence of diabetes, gout, thyroid disease, or thumb osteoarthritis were considered independent variables. RESULTS: A total of 58 of 140 patients (41%) who presented with multiple trigger digits exhibited concomitant carpal tunnel symptoms, compared with 26 of 160 (16%) patients who presented with a single trigger digit. Significant independent predictors of CTS associated with trigger digits in the final regression model included multiple trigger digits (odds ratio = 3.6; subjects with multiple trigger digits had significantly higher odds of carpal tunnel presentation than subjects with a single trigger digit) and diabetes (odds ratio = 1.9; diabetic subjects had significantly higher odds of carpal tunnel presentation than nondiabetics). CONCLUSIONS: A greater than 3-fold increase in the relative risk of CTS development exists in patients undergoing treatment for multiple trigger digits, compared with those undergoing treatment for a single trigger digit. Awareness of this association may aid in the early diagnosis and treatment of CTS in patients presenting with multiple trigger digits. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic III.

Management of pediatric trigger thumb and trigger finger.

Pediatric trigger thumb and trigger finger represent distinct conditions and should not be treated like adult acquired trigger finger. Over the last two decades, our understanding of the natural history of pediatric trigger thumb and the etiology and surgical management of pediatric trigger finger has improved. Pediatric trigger thumb may spontaneously resolve, although resolution may take several years. Open surgical release of the A1 pulley of the thumb is an alternative option that nearly uniformly restores thumb interphalangeal joint motion. Surgical management of pediatric trigger finger with isolated release of the A1 pulley has been associated with high recurrence rates. Awareness of the anatomic factors that may contribute to triggering in the pediatric finger and willingness to explore and address other involved components of the flexor mechanism can prevent surgical failure.

Resection of the flexor digitorum superficialis for trigger finger with proximal interphalangeal joint positional contracture.

PURPOSE: Open release of the A1 pulley is a widely known procedure for the treatment of trigger finger. A subset of patients presents with both trigger finger and a positional contracture of the proximal interphalangeal (PIP) joint. These patients usually have a long history of trigger finger or have already undergone a surgical release of the annular pulley. This study is a retrospective review of the outcomes of resection of the flexor digitorum superficialis (FDS) for patients whose trigger finger was associated with a positional contracture of the PIP joint. METHODS: Thirty-six patients (39 fingers) were treated by resection of the FDS after section of the A1 pulley. The mean age of the patients was 63 years (range, 45-90 y). Seven patients (19 %) had previously undergone an open release of the A1 pulley and had developed a positional contracture of the PIP joint 2 to 5 months afterward. We performed a retrospective review with a mean follow-up of 30 months (range, 12-60 mo). No patient was lost to follow-up. The active range of motion was recorded at the PIP joint before and after surgery. RESULTS: The mean preoperative positional contracture of the PIP joint was 24° (range, 15°-30°). The mean postoperative positional contracture of the PIP joint was 4° (range, 0°-10°). The most commonly affected digit was the middle finger (26 fingers, 67%). In 28 fingers (72%), full extension was achieved following only the surgical procedure. The remaining 11 fingers (28%) had a postoperative residual positional contracture (range, 5°-10°). However, all fingers achieved a full range of motion after physical therapy and an injection of betamethasone. All of the resected tendons had histological damage. CONCLUSIONS: This technique is a useful treatment for selected patients whose trigger finger is associated with a positional contracture.

Pediatric trigger thumb with locked interphalangeal joint: can observation or splinting be a treatment option?

BACKGROUND: The purpose of this study is to report the natural history of pediatric trigger thumb with locked interphalangeal joint, the efficacy of a splint for this condition, and the outcome of late surgery. METHODS: Medical records of 64 patients were retrospectively reviewed. Patients were treated with a coil splint when parents and patients accepted; otherwise, regular observation was conducted. Splint application and/or observation were terminated either when the patient gained full range of active motion without snapping, or underwent surgical intervention. RESULTS: In splint group, 92% of the patients experienced complete symptom relief in 22 months, whereas 60% resolved completely in 59 months in observation group. The differences were statistically significant. One thumb in a patient with bilateral involvement remained locked while the other completely resolved. The rest of the patients also showed improved symptom from locking to snapping. Four patients with residual snapping underwent surgery at the age of 8 years and above without any deformity and complication. CONCLUSIONS: Splint was efficient in shortening the time for symptom relief; however, the natural history revealed the self-limiting nature of this condition. Late surgery was safe and effective for residual snapping and can be presented as one treatment option to the patients and families, combined with conservative treatment. LEVEL OF EVIDENCE: Level III--retrospective comparative study.

Pressure generated by syringes: implications for hydrodissection and injection of dense connective tissue lesions.

OBJECTIVE: Hydrodissection and high-pressure injection are important for the treatment of dense connective tissue lesions including rheumatoid nodules, Dupuytren's contracture, and trigger finger. The present study determined the optimal syringes for high-pressure injection of dense connective tissue lesions. METHODS: Different sizes (1, 3, 5, 10, 20, and 60 mL) of a mechanical syringe (reciprocating procedure device) with a luer-lock fitting were studied. Twenty operators generated maximum pressure with each mechanical syringe size, and pressure was measured in pounds per square inch (psi). Subsequently, 223 dense connective tissue lesions were injected with different sizes of syringes (1, 3, or 10 mL). Outcomes included (i) successful intralesional injection and (ii) clinical response at 2 weeks. RESULTS: Smaller syringes generated significantly more injection pressure than did larger syringes: 1 mL (363 ± 197 psi), 3 mL (177 ± 96 psi), 5 mL (73 ± 40 psi), 10 mL (53 ± 29 psi), 20 mL (32 ± 18 psi), and 60 mL (19 ± 12 psi). Similarly, smaller syringes were superior to larger syringes for intralesional injection success: 10 mL: 34% (15/44) vs. 1 mL: 100% (70/70) (p < 0.001) and 3 mL: 91% (99/109) (p < 0.001). CONCLUSION: Smaller syringes (≤ 3 mL) are superior to larger syringes (≥ 5 mL) for successful hydrodissection and high-pressure intralesional injection of dense connective tissue lesions.

Cardiac Amyloidosis Screening at Trigger Finger Release Surgery.

Cardiac amyloidosis is often preceded by orthopedic manifestations such as carpal tunnel syndrome, and 10% of patients who underwent idiopathic carpal tunnel release surgery will have biopsy-confirmed amyloid deposits in the tenosynovial sheath. Trigger finger is also commonly reported in patients with amyloidosis and involves the same tendon sheath as carpal tunnel syndrome, but the prevalence of amyloid deposition is unclear. This prospective cross-sectional study enrolled 100 patients aged ≥50 years at the time of surgery for idiopathic trigger finger. Patients underwent release surgery, and a sample of the tenosynovium of the affected finger was excised, stained with Congo red, and subtyped with mass spectrometry if amyloid was demonstrated. Further cardiac evaluation was performed in patients with amyloid deposition. Of the 100 patients (mean age 65.5 ± 8.1 years) enrolled, only 2 demonstrated amyloid deposits on Congo red staining. One patient with previous proteinuric kidney disease had fibrinogen A α-chain amyloidosis, and the other patient had untyped amyloidosis. Neither patient had cardiac involvement. A total of 13 of the 100 patients underwent concomitant carpal tunnel release surgery, and 2 of these patients had amyloid deposits in the carpal tunnel with "false-negative" samples from the trigger finger tenosynovium. In conclusion, biopsy during trigger finger release surgery demonstrated a 2% yield for amyloidosis, which is significantly lower than the previously published yield of 10% during carpal tunnel release surgery. This observation has important implications for the development of diagnostic algorithms to screen patients for amyloidosis during orthopedic operations.

Ultrasonographic assessment of clinically diagnosed trigger fingers.

This study examines flexor digitorum tendons and A1 pulley in patients presenting trigger fingers using high-resolution ultrasonography (US), determines the accurate causes of trigger fingers, and analyzes the relationship between clinical data and US findings. As much as 50 trigger fingers of 41 patients were examined by high-resolution US, and the US findings were analyzed as tendon thickness, fibrillar echotexture, tendon margin, fluid collection, A1 pulley thickening, tendon sheath cyst, and metacarpophalageal (MCP) joint abnormalities. The affected fingers were compared with the asymptomatic opposite sides. Right thumb and ring finger were the most common fingers involved. Mean thickness of flexor digitorum tendons of the affected fingers was increased significantly, compared with that of the opposite fingers. There were various US findings in flexor digitorum tendons as follows; loss of normal fibrillar echogenic pattern (14%), irregularity or blurring of the tendon margin (62%), and fluid collection in the tendon sheath (16%). Thickening of A1 pulley was noted in 44% of fingers, and mean thickness of A1 pulley was 0.7 mm. As much as 6% of fingers had the sheath cysts and 4% of fingers had abnormalities of MCP joints. The patients with extension difficulty of the fingers had thicker flexor digitorum tendon than those without. The patients with locking fingers had more blurred margin of the tendon than those without. US can detect various lesions in clinical trigger fingers, and some US findings correlated with clinical findings.

Risk factors for carpal tunnel syndrome or trigger finger following distal radius fracture: a nationwide study.

New-onset carpal tunnel syndrome (CTS) and trigger finger after distal radius fractures (DRFs) with or without open reduction and internal fixation (ORIF) have been reported inconsistently across different studies. This study assessed the incidence of CTS and trigger finger after DRFs using Taiwan National Health Insurance Research Database. In total, 1454 patients in the case (ORIF) cohort and 1454 patients in the control (non-ORIF) cohort were included in this retrospective study. The mean age was approximately 55 years old, and the female to male ratio was approximately 3/2. Nine patients underwent carpal tunnel release (CTR) surgery after diagnosis of CTS in the case group, and no patients did in the control group; whereas 19 cases of CTS were diagnosed without CTR in the case group, and 4 such cases were observed in the control group. Five cases of trigger finger were diagnosed in the case group, and 3 cases were diagnosed in the control group. CTS were significantly associated with ORIF for DRFs within 9 months after the fracture, whereas trigger finger was not significantly different between groups. Diabetes mellitus was a significant risk factor for CTS and trigger finger within 9 months after the incidence of DRFs.

Correlations between clinical presentations of adult trigger digits and histologic aspects of the A1 pulley.

PURPOSE: We aimed to report by light microscopy the normal histology of the A1 pulley, describe the histologic abnormalities of A1 pulleys in trigger digits, and look for possible correlations between these findings and the severity of the disease. METHODS: In a series of 104 trigger digits operated on in 80 adult patients, the A1 pulleys were removed and histologically studied. The findings were compared with 55 normal A1 pulleys obtained from fresh-frozen cadaveric specimens. RESULTS: The normal A1 pulley was composed of 3 layers: layer I, an inner, avascular, concave unicellular or bicellular gliding layer containing cartilage-like cells; layer II, a middle layer, also avascular, characterized by spindle-shaped fibroblasts; and layer III, an outer, richly vascularized layer, continuous with the membranous tendons sheath. We used a 3-grade classification, increasing in severity, to describe the histologic abnormalities observed in trigger digit A1 pulleys. Mild abnormalities (grade 1) were those with a fibrocartilaginous gliding surface almost intact. The margin between the fibrocartilaginous and membranous portions of the pulley was well delineated. In moderate abnormalities (grade 2), the avascular fibrocartilaginous gliding surface appeared fissured and thinner. The inner layer (I) was interrupted and replaced by fibrous tissue, with fissures that did not cross through the middle layer (II). A mild vascular network hyperplasia was observed in the outer layer (III), which began to invade the fibrocartilage. In severe abnormalities (grade 3), the fibrocartilaginous gliding surface was thin, discontinuous, or even completely destroyed. The vascular network hyperplasia became excessive and reached the synovial space of the flexor tendon sheath. The histologic features were correlated with the severity of the clinical symptoms (p < .001). CONCLUSIONS: The histologic abnormalities observed in the A1 pulley of trigger digits are characteristic and not related to inflammation. As the trigger digit worsens, the gliding surface begins to wear and is gradually replaced by a secondary invasive hyperplasia from the outer layer. These abnormalities could be caused by a modification or an increase of the mechanical stresses along the flexor tendons.

Congenital hand differences.

This article explores recent developments for 6 common congenital hand differences, including polydactyly, syndactyly, camptodactyly, clinodactyly, trigger thumb, and cleft hand. These differences are challenging because the surgeon must understand the potential for both functional and social (ie, appearance) issues in order to provide ideal treatment for each child and family. Therapy or surgical correction plays a role for most of these children. Recent investigations have provided additional data on the expected outcomes following intervention.

Length and landmark of A1 pulley in hand: an anatomical study.

OBJECTIVE: The purpose of the present study was to identify length and landmark of proximal of A1 pulley in hand. MATERIAL AND METHOD: An anatomical study of the length and landmark of A1 pulley in hand was performed in 510 fingers and thumbs from 51 preserved cadavers. There were 25 females and 26 males whose ages at the time of death ranged from 48 to 89 years. RESULTS: The lengths of A1 pulley were 5.30 +/- 0.53 mm in average of thumbs and 6.32 +/- 0.17, 6.58 +/- 0.19, 6.32 +/- 0.20, and 5.30 +/- 0.49 for the index, middle, ring, and small finger respectively. The average of all fingers were 6.13 +/- 0.17 mm. The margin from the proximal edge of A1 pulley related to the perpendicular line from posterior superior prominent of metacarpal head to the volar aspect of its fingers, which was in the same line for 327 (64.1%) fingers and thumbs, and for 464 (91.0%) fingers and thumbs were differences < or = 1 mm, and for 509 (99.8%) were differences < or = 2mm to proximal edge of A1 pulley of its finger and thumb. CONCLUSION: The posterior superior prominent of metacarpal head line in perpendicular to the volar aspect of its finger and thumb may be used as an anatomical landmark to predict of the proximal edge of A1 pulley with reasonable accuracy. The length of A1 pulley can serve as an important guide for the distal termination ofA1 pulley release.

Identification of the location of the A1 pulley combining palpation technique with palm landmarks and percutaneous release of A1 pulley with a 19-gauge needle: A cadaveric study.

The aims of this study were to identify the location of the A1 pulley combining palpation technique with superficial palm landmarks and to determine the efficacy and safety of A1 pulley percutaneous release with a 19-gauge needle. Fourteen fresh frozen cadaveric specimens were used: 56 fingers and 14 thumbs. The location of the A1 pulley was based on anatomical landmarks and was identified in all digits. Complete release of the A1 pulley occurred in 60 of the 70 digits (85.7%). The length of the A1 pulley in thumbs was 5.7 mm and in other fingers 4.5 mm. There were no signs of neurovascular bundle injuries. The mean distance between needle pathway and neurovascular bundle was 4.3 mm in the thumbs and 6.5 mm in the other fingers. There were no total flexor tendon injuries. The location of the A1 pulley can be predicted with success. Percutaneous release of the A1 pulley with a 19-gauge needle shows acceptable results in both safety and efficacy.

Three-dimensional printing of a microneedle array on personalized curved surfaces for dual-pronged treatment of trigger finger.

The hand function of patients who suffer from trigger finger can be impaired by the use of traditional splints. There is also a risk of systemic side effects with oral non-steroidal anti-inflammatory drugs (NSAIDs) used for pain relief. Microneedle-assisted transdermal drug delivery offers an attractive alternative for local delivery of NSAIDs. However, traditional microneedle arrays fabricated on flat surfaces are unable to deliver drugs effectively across the undulating skin surface of affected finger(s). In this study, using 3D printing, a dual-function microneedle array has been fabricated on personalized curved surfaces (microneedle splint) for drug delivery and splinting of the affected finger. The novel microneedle splint was assessed for its physical characteristics and the microneedles were shown to withstand up to twice the average thumb force without fracturing. An average skin penetration efficiency of 64% on dermatomed human cadaver skin was achieved and the final microneedle splint showed biocompatibility with human dermal cell lines. A significantly higher amount of diclofenac permeated through the skin by 0.5 h with the use of the microneedle splint as compared to intact skin. The fabricated microneedle splint can thus be a potential new approach to treat trigger finger via personalized splinting without affecting normal hand function.

Risk factors for return with a second trigger digit.

The purpose of this study was to determine predictors of return to the same practice with a second idiopathic trigger digit. A total of 2234 patients with Quinnell grade 2 or greater (objective triggering) of one or more digits were retrospectively analysed. A total of 490 of 2234 (22%) patients returned to the same practice with a second trigger digit, with an average follow-up time of 2.1 years (range, 7 days to 10 years). Predictors of return with a second trigger digit included carpal tunnel syndrome, Type 1 diabetes mellitus and duration of follow-up in years. Patients diagnosed with idiopathic trigger digit can be advised that about one in five will return to the same practice with another trigger digit, with approximately double the risk in patients that have carpal tunnel syndrome or Type 1 diabetes.

Percutaneous release of trigger fingers.

Open surgery has been indicated as the surgical treatment for trigger finger for many years; however, minimally invasive techniques are replacing conventional methods. Minimally invasive techniques enable early recovery of the patient with minimal damage to soft tissues. The authors' study showed that levels of effectiveness of open surgical and percutaneous methods were superior to those of the conservative method using corticosteroid based on the cure and reappearance rates of the trigger. Percutaneous pulley release for treating trigger finger is a safe, effective, and minimally invasive surgical alternative.