[THE CONGENITAL TRIGGER THUMB - CLINICAL PRESENTATION AND TREATMENT].

INTRODUCTION: Congenital trigger thumb is found in 0.3% of all children. There is an ongoing debate whether the finding of a congenital trigger thumb is truly congenital or is developmental, although the current tendency in the literature is to see it as a developmental finding. When a toddler is found to have a thumb with the interphalangeal joint locked in flexion there are a number of differential diagnoses to be considered. Absence or aberrance of the extensor mechanism, arthrogryposis, spasticity and the clasped thumb deformity all may explain this finding. The most common diagnosis of a toddler found with his thumb locked in flexion or extension is the congenital trigger thumb. Clinical inspection will reveal, in most cases, a distinct nodule at the base of the thumb named Notta's Node, and a thumb fixed in either flexion or extension at the interphalangeal joint. A trial of conservative treatment extending for at least six months should be made, but once this fails, surgical intervention is the rule of thumb. Surgical intervention consists of ligation of the A1 pulley while preserving structures in its vicinity.

Pediatric Trigger Digits.

Pediatric trigger thumb presents not at birth but early in childhood. Most evidence suggests that it is caused by a developmental size mismatch between the flexor pollicis longus tendon and its sheath. Patients generally present with the thumb interphalangeal joint locked in flexion. Surgical reviews report near universally excellent outcomes after open release of the A1 pulley. However, recent reports indicate that there may be a role for nonsurgical treatment for families that are willing to wait several years for possible spontaneous resolution of the deformity. Triggering in digits other than the thumb in children is generally associated with an underlying diagnosis including anatomic abnormalities of the tendons, and metabolic, inflammatory, and infectious etiologies. Although some have advocated nonsurgical treatment, surgery is often necessary to address the underlying anatomic etiology. More extensive surgery beyond simple A1 pulley release is often required, including release of the A3 pulley and resection of a slip of the flexor digitorum superficialis tendon.

[The operative treatment of a bowstring phenomenon of the thumb in childhood: case report and literature review]. / Die operative Behandlung des veralteten Bogensehneneffektes des Daumens im Kindesalter, Fallbericht und Literaturrecherche.

INTRODUCTION: The operative treatment of a congenital trigger thumb comprises splitting the A1 pulley under conditions of hand surgery. One complication is cutting through the A2 pulley. In this case a bowstring phenomenon will result. CASE REPORT: We report about the reconstruction of the A2 pulley by using a transosseous fixed tendon strip for a now 7-year-old boy with an impressive bowstring phenomenon with profound impairment of thumb function and power after surgery of a trigger thumb at the age of 2 years. DISCUSSION: The iatrogenic splitting of the A2 pulley during the operative treatment of a congenital trigger thumb and the treatment of the resulting bowstring phenomenon are not sufficiently reflected at the literature. In adulthood, several different methods of pulley reconstruction are described. CONCLUSION: In our opinion this technique is a safe and easy option to reconstruct the A2 pulley without expensive fibre anchors and enables a broad replacement without compromising extension tendons. Also outdated bowstring phenomenons are sufficiently stabilised. A good hand function with full preservation of finger flexibility and power is ensured as well.

Congenital trigger thumb in children: electron microscopy and immunohistochemical analysis of the first annular pulley.

Although numerous studies have been performed on congenital trigger thumb (CTT), the pathogenesis is still unknown. Cytocontractile proteins and myofibroblasts are present during soft-tissue contraction, and they may have a role in CTT. The aim of the study is to clarify the immunohistochemical and the electron microscopy characteristics of the first annular (A-1) pulley in CTT. The specimens from the A-1 pulleys were collected from 22 children with CTT. Electron microscopy was used to study the last five specimens. Immunohistochemistry staining demonstrated that all specimens stained positively for vimentin and for α-smooth muscle actin, and stained negatively for desmin. Electron microscopy showed fibroblasts in collagenous matrix, which contain vimentin-like material and associated at the surface with elastin-like tubular matrix filaments and elastin fibers. In two specimens, a few cells showed markers of myofibroblastic differentiation. The presence of the cytocontractile proteins and myofibroblasts suggests proliferation of fibrous tissues during either the intrauterine or extrauterine phase of development and may account for the presence of congenital stenosis at the level of the A-1 pulley. We believe that CTT may be developmental; if the process started in the intrauterine phase it might present as a fixed flexion contracture and will show mature fibroblasts. If the process started in the extrauterine phase, it might present as triggering first and will show myofibroblastic changes, then with the maturation of the fibrous tissue, result in a fixed flexion contracture.

[Percutaneous release of trigger thumb in children: 63 cases]. / Le traitement percutané du pouce à ressaut chez l'enfant : à propos de 63 cas.

INTRODUCTION: Congenital trigger thumb is secondary to a conflict between the flexor pollicis longus tendon and its inextensible tendon sheath. Though, the exact aetiology is still unknown, its treatment is usually surgical. PATIENTS: The authors present their experience of treating 52 consecutive patients with 63 trigger thumbs, with mean age 32 months, range (12 months to five years). Twenty-nine boys and 23 girls. Right thumb 37 and left thumb 26, 11 patients had have bilateral trigger thumb. Each was exclusively treated by percutaneous release of the A1 pulley using a needle. RESULTS: Fifty-two with 50 treated trigger thumbs were available for follow-up. The mean follow-up after this procedure was 28 months (range 12-30 months). Fourty-eight thumbs had a good result without any recurrence of triggering. Two thumbs had recurrent triggering and were subsequently successfully treated by open release. No thumbs demonstrated any neurovascular deficit clinically. CONCLUSION: Percutaneous release of congenital trigger thumb can be performed safely and effectively in children by a surgeon specializing in hand surgery.

Pediatric trigger thumb in identical twins: congenital or acquired?

Pediatric trigger thumb is an uncommon condition with a calculated incidence of 3 per 1000 live births or less. Some reports have suggested a congenital etiology while others could not find a single case of pediatric trigger thumb at birth. This article reports the occurrence of bilateral trigger thumbs in identical twins, age 3 years and 9 months, affecting their thumbs to similar extents, which may suggest a congenital etiology.Congenital etiology for trigger thumb has been proposed for many reasons: occurrence in infants, occurrence in twins, occasional bilaterality, possible presence of triggering at birth, and absence of history of trauma. The occurrence of pediatric trigger thumb in twins has been reported 3 times in the literature; all reported cases were bilateral, as in our case.The mean age at presentation of pediatric trigger thumb is 2 years. The thumb is usually held in a fixed flexion position (mimicking a fracture). Examination usually reveals a palpable nodule in the flexor pollicis longus tendon at the metacarpal joint. This is an important clinical sign. Triggering in children, however, is rare. Macroscopically, there is a nodular thickening of the tendon itself. Pathological changes can be found in the tendon, tendon sheath, or both. A specimen taken from one of the nodules in our case showed degenerative changes while those from both pulleys were normal.Pediatric trigger thumb responds predictably to A1 pulley release, preferably before age 4 years, although milder cases may resolve spontaneously.

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.

The congenital trigger thumb: is release of the first annular pulley alone sufficient to resolve the triggering?

The recognized treatment of persistent congenital trigger thumb (CTT) is surgical release of the flexor pollicis longus (FPL) tendon by transection of the first annular (A1) pulley at the thumb metacarpal head. Twenty-seven children with persistent CTT were operated between 2000 and 2004. The average age at surgery was 34 months. In 16 patients, the CTT appeared unilaterally and was the sole anomaly in the hand. The others suffered from either multiple hand abnormalities or another syndrome. In only 3 of the 16 thumbs (ie, 19%) division of just the A1 pulley at the metacarpal (MC) head was sufficient to relieve the triggering. In 11 thumbs (69%), a structure other than the sheath and distally from the A1 pulley, up to halfway the proximal phalangeal shaft (as a single entity), was discovered and had to be released also. A separate annular pulley, distal to the A1 pulley and other than the A2 pulley, was found in 2 cases (13%). In both cases, transection of this separate annular pulley alone sufficed. Complete release of the FPL was obtained in all, and none presented with postoperative complications at an average of 24 months' follow-up. Our clinical study suggests that a separate annular pulley system may exist, which has to be transected to allow for free FPL excursion in perhaps as many as 2 out of 3 CTTs. In our study group, this was not accompanied by complications.