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A 6-year-old otherwise healthy girl presented with a Wassel VI duplication of the left thumb metacarpal and triphalangeal radial and ulnar thumbs. The patient underwent successful thumb reconstruction by transposition of the distal ulnar thumb onto the radial thumb metacarpal. To the best of our knowledge, this case report represents the first published anatomical dissection and surgical reconstruction of a Wassel VI duplication with triphalangeal radial and ulnar thumbs., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Wu et al. introduced a modified radiographic system that allows classification of all forms of CTD with excellent interobserver and intraobserver reliability. No study to date has evaluated the radiographic characteristics of Wu et al. type C3 CTD with osseous attachment at the level of the metacarpal., Objective: This study aimed to evaluate the radiographic features of type C3 CTD according to the system of Wu et al., to describe the different anatomical subtypes of the duplication, and to propose a categorization approach to distinguish diverse surgical strategies based on the radiographic anatomy of this specific subtype of duplication., Methods: We performed a retrospective analysis of 215 patients (221 thumbs) diagnosed with Wu et al. type C3 CTD at our Institution between 2015 and 2021. We evaluated all CTDs by examining the alignment of the interphalangeal (IP) and metacarpophalangeal (MP) joints and by assessing the presence of abnormal hypertrophic epiphysis of the primary thumb on posteroanterior (PA) radiographs. The proposed classification system has four types: Type I with good alignment of both MP and IP joints, Type II with ulnar deviation of the MP joint, Type III with radial deviation in the MP joint and Type IV with abnormal hypertrophic epiphysis of the distal phalanx of the main thumb with ulnar deviation of the IP joint with or without ulnar deviation of the MP joint., Results: There were 140 male and 75 female patients with CTD (221 thumbs). There were 65 left, 144 right and 6 bilateral forms. The right-to-left, male-to-female and unilateral-to-bilateral ratios were 2.2:1, 1.9:1 and 35.8:1 respectively. The mean age at surgery was 22.3 ± 11.8 months (range, 8-80). The proposed classification system allowed the classification of all CTDs (n = 221). Specifically, 53 fingers were classified as Type I (24%), 136 as Type II (61.5%), 21 as Type III (9.5%), and 11 as Type IV (5%)., Conclusion: The proposed system is based on radiographic pathoanatomy and complements that of Wu et al. by identifying four distinct subtypes of deformity. It has the potential to improve inter-professional communication and guide surgery in patients with Wu et al. type C3 CTD. However, our results are preliminary and further research is needed to validate them., Level of Evidence: III., (© 2024. The Author(s).)

Functional impairment, absence, or traumatic loss of the thumb is associated with considerable morbidity. A fully functioning thumb is estimated to account for 40% of hand function. An array of options exists for thumb reconstruction, and the intervention selected must be tailored to each individual patient. Pollicization is a powerful and elegant operation that can dramatically improve function for many patients. However, the surgeon and patient must be keenly aware that pollicization does not construct a "normal" thumb. Herein, we present a stepwise approach to treatment, including surgical nuances, alternatives to pollicization, complications, and outcomes., Competing Interests: Disclosures The authors have no conflicts of interest to disclose., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Level of Evidence: III., Competing Interests: Declaration of conflicting interestsThe authors declare no potential conflicts of interest with respect to the research, authorship, and publication of this article.

Background: De Quervain tenosynovitis of the wrist is a common pathology. The primary aim of this study is to determine the prevalence of extensor pollicis brevis and abductor pollicis longus (APL) anatomical variations in association with de Quervain tenosynovitis. The secondary aim was to compare additional patient-specific factors associated with de Quervain tenosynovitis., Methods: This retrospective study included 172 patients with de Quervain tenosynovitis who underwent first dorsal compartment release and 179 patients with thumb carpometacarpal (CMC) arthritis who underwent thumb CMC arthroplasty between August 1, 2007, and May 1, 2022. The CMC group was chosen as the control group because the study surgeons perform APL suspensionplasty as the primary procedure for thumb CMC arthritis, allowing for a comparison group without de Quervain tenosynovitis. Exclusion criteria included patients undergoing revision surgery, patients undergoing thumb CMC procedure other than APL suspensionplasty, and patients with both CMC and first dorsal compartment diagnoses. Demographics, clinical variables, and intraoperative findings were collected through retrospective chart reviews., Results: Patients in the de Quervain tenosynovitis group tended to be younger (51 years, range: 23-92 years vs 63 years, range: 28-85 years), women (86.1% vs 77.1%), and more commonly of African American or black race (15.7% vs 3.9%) and Asian race (5.2% vs 0%). There was a higher prevalence of tendon subcompartments (79.1% vs 64.2%), but fewer number of APL slips (38.3% vs 20.7% 2 or fewer slips) seen in the de Quervain tenosynovitis group., Conclusion: Anatomical variation exists between patients with and without de Quervain tenosynovitis. The presence of tendon subcompartments but not an increased number of tendon slips is associated with de Quervain tenosynovitis., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: B.E. is a paid consultant of Synthes, owns stock in Johnson & Johnson and Pfizer, and is a board member for AAOS and American Society for Surgery of the Hand. D.Z. receives research support from Akcea Therapeutics unrelated to this project. He has also received a speaker honorarium from Alnylam Pharmaceuticals, is a committee member of the American Society for Surgery of the Hand, and is on the editorial board for The Journal of Hand Surgery (Asian-Pacific Volume). P.B. is on the editorial board for Journal of Hand Surgery and Techniques in Hand and Upper Extremity. C.L. and S.M. declare that they have no conflict of interest.

Purpose: The Thumb Grasp and Pinch Assessment (T-GAP) is a new instrument for evaluating thumb use in children with congenital hypoplastic thumbs. The assessors video-record the children while they perform nine specific activities and score their grasp types using T-GAP. A high T-GAP score indicates more mature grasp patterns. The developers reported the instrument's validity and reliability for index finger pollicization. This study investigated T-GAP's validity and reliability in children with reconstructed hypoplastic thumbs., Methods: Four hand surgeons and two hand therapists from two hospitals rated video clips of 20 Manske type II and IIIa hands twice in 17 patients who performed the T-GAP at least 1 year after opposition transfer and thumb ligament reconstruction. To investigate the validity, we calculated correlation coefficients for T-GAP scores and clinical outcomes, including thumb ROM, grip and pinch strength, and visual analog assessments of thumb function and appearance. To estimate T-GAP's inter- and intrarater reliability, we calculated intraclass correlation coefficients and their 95% confidence intervals (CIs)., Results: Thumb Grasp and Pinch Assessment score showed a strong linear correlation (r = 0.815-0.944) and a moderate to strong nonlinear correlation (ρ = 0.527-0.744) with visual analog scale assessments of thumb function and appearance, respectively; a moderate nonlinear correlation (ρ = 0.464) with grip strength; and a moderate nonlinear correlation (ρ = 0.541) with thumb MCP joint range of motion. The intraclass correlation coefficient for the interrater reliability was 0.892 (95% CI, 0.768-0.954) in round 1 and 0.898 (95% CI, 0.754-0.959) in round 2, and for intrarater reliability, the mean was 0.882 (95% CI, 0.785-0.980)., Conclusions: Thumb Grasp and Pinch Assessment score had a moderate to strong construct validity and a moderate concurrent validity. Both inter- and intrarater reliability was strong., Clinical Relevance: This study supports the T-GAP instrument's validity and reliability for assessing functional outcomes in congenital hypoplastic thumb reconstruction., (Copyright © 2024 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.)

We report the application and results of skin defect coverage using the free lateral great toe flap in revision surgery for residual postoperative deformities in Wassel-Flatt type IV-D thumb duplications. This retrospective study included five patients treated between June 2020 and September 2021 to correct angular deformity and repair the secondary skin defect. All the flaps survived. The patients were followed up for 8-12 months and all the reconstructed thumbs had a satisfactory appearance. The results of the Japanese Society for Surgery of the Hand scoring system were excellent in one patient, good in three patients and fair in one patient. The results of the Alignment, Ulnar and Radial stability, Range of motion and Aesthetical aspects (ALURRA) scoring system were good in four patients and moderate in one patient. Level of evidence: IV., Competing Interests: Declaration of conflicting interestsThe authors declare no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Nail-patella syndrome (NPS) is an autosomal dominant disease caused mostly by mutations in the LMX1B gene and is characterized by hypoplastic nails, hypoplastic patella, elbow deformities, glaucoma, and nephropathy, sometimes leading to kidney failure. The combination and the severity of symptoms vary greatly from patient to patient. Because a kidney biopsy may show nonspecific findings, patients with nephropathy alone may not be diagnosed without undergoing genetic testing. We examined the case of a 6-year-old girl with persistent high proteinuria who was not diagnosed by kidney biopsy but had a diagnosis of a de novo mutation in the LMX1B gene following genetic testing. Retrospectively, only the thumbs showed triangular lunulae, while the third and fourth fingers lacked skin creases over the distal interphalangeal joints, which is subtle but characteristic of NPS. Notifying pediatric nephrologists of these findings can help avoid unnecessary kidney biopsies and lead to early detection of the disease., (© 2024. The Author(s), under exclusive licence to International Pediatric Nephrology Association.)

Genetic variants in the zone of polarizing activity regulatory sequence (ZRS) that induce ectopic expression of the SHH gene have been associated with different ZRS-related phenotypes. We report the first patient with a de novo variant, c.423+4916 T>C, in ZRS (previously classified as a variant of uncertain significance) that causes tibial hemimelia-polysyndactyly-triphalangeal thumb syndrome (THPTTS). A two-month-old male patient presented with bilateral preaxial polydactyly, triphalangeal thumb, and tibial agenesis and was heterozygous for the variant c.423+4916T>C (neither of his parents was a carrier). The findings obtained from the family study were sufficient to reclassify the variant from "uncertain significance" to "likely pathogenic" according to three criteria from the American College of Medical Genetics and Genomics guidelines, as follows: (1) absence of gnomAD, (2) confirmation of paternity and maternity, and (3) strong phenotype-genotype association. In ZRS-associated syndromes, a wide clinical spectrum has been observed, ranging from polydactyly to THPTTS; our patient has the most severe and rare phenotype. We did not perform functional assays. However, the c.423+4916T>C variant is flanked by three variants, which have been proven not only to cause the phenotype but also to increase the expression of SHH . Through all this data gathering, we consider the c.423+4916T>C variant to be causative of THPTTS.

Background: Kagami-Ogata syndrome (KOS) and Temple syndrome (TS) are two imprinting disorders characterized by the absence or reduced expression of maternal or paternal genes in the chromosome 14q32 region, respectively. We present a rare prenatally diagnosed case of recurrent KOS inherited from a mother affected by TS., Case Presentation: The woman's two affected pregnancies exhibited recurrent manifestations of prenatal overgrowth, polyhydramnios, and omphalocele, as well as a small bell-shaped thorax with coat-hanger ribs postnatally. Prenatal genetic testing using a single-nucleotide polymorphism array detected a 268.2-kb deletion in the chromosome 14q32 imprinted region inherited from the mother, leading to the diagnosis of KOS. Additionally, the woman carried a de novo deletion in the paternal chromosome 14q32 imprinted region and presented with short stature and small hands and feet, indicating a diagnosis of TS., Conclusions: Given the rarity of KOS as an imprinting disorder, accurate prenatal diagnosis of this rare imprinting disorder depends on two factors: (1) increasing clinician recognition of the clinical phenotype and related genetic mechanism, and (2) emphasizing the importance of imprinted regions in the CMA workflow for laboratory analysis., (© 2024. The Author(s).)

Townes-Brocks syndrome (TBS) is an autosomal dominant disorder characterised by the triad of anorectal, thumb, and ear malformations. It may also be accompanied by defects in kidney, heart, eyes, hearing, and feet. TBS has been demonstrated to result from heterozygous variants in the SALL1 gene, which encodes zinc finger protein believed to function as a transcriptional repressor. The clinical characteristics of an atypical TBS phenotype patient from a Chinese family are described, with predominant manifestations including external ear dysplasia, unilateral renal hypoplasia with mild renal dysfunction, and hearing impairment. A novel heterozygous variant c.3060T>A (p.Tyr1020*) in exon 2 of the SALL1 gene was identified in this proband. Pyrosequencing of the complementary DNA of the proband revealed that the variant transcript accounted for 48% of the total transcripts in peripheral leukocytes, indicating that this variant transcript has not undergone nonsense-mediated mRNA decay. This variant c.3060T > A is located at the terminal end of exon 2, proximal to the 3' end of the SALL1 gene, and exerts a relatively minor impact on protein function. We suggest that the atypical TBS phenotype observed in the proband may be attributed to the truncated protein retaining partial SALL1 function., (© 2024 Asian Pacific Society of Nephrology.)

Linburg-Comstock syndrome is an acquired symptomatic restrictive thumb index finger flexor tenosynovitis involving a hypertrophic tenosynovium between flexor pollicis longus and flexor digitorum profundus. Patients may report synkinetic movement of the thumb and index finger, pain and swelling. We present the case of a woman in her 80s who presented with painless Linburg-Comstock syndrome after a trapeziectomy 4 months earlier for trapeziometacarpal arthritis. A literature review of PubMed-indexed case reports found that Linburg-Comstock syndrome has never been described in a post-trapeziectomy patient. This unusual presentation that arose as a side effect of hand surgery remains unreported in the literature. We present this unique complication as the first such case in the world. This case report is a valuable addition to the existing knowledge on the complications of trapeziectomy surgery., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Congenital clasped thumb is associated with deficient thumb extensor tendons. Reconstruction includes tendon transfer. Here, we describe a variant of the abductor pollicis longus (APL) tendon, not previously reported, contributing to the flexion deformity. The purpose of this study is to report examples of and offer surgical repair techniques for APL variants identified in patients with clasped thumb., Methods: We reviewed records of 11 consecutive patients undergoing reconstruction for clasped thumb. Surgical anatomy of the APL tendon was evaluated in all patients, followed by release of aberrant APL attachments. Participants were invited to return for an in-person assessment with a certified hand therapist. Data were collected regarding intraoperative findings, surgical techniques for reconstruction, postoperative thumb motion, and patient and caregiver satisfaction., Results: Eleven children (12 thumbs) underwent aberrant APL release and rerouting between 2019 and 2021. Preoperatively, all thumbs were passively correctible to 0° of extension. In all patients, the APL was found to terminate palmar to the metacarpophalangeal (MCP) joint, creating an MCP flexion moment when tensioned. The average age at surgery was 7 years (range: 1-15 years), and the average follow-up was 14.2 months (range: 1-21 months). The mean postoperative thumb radial abduction was 55° (range: 20°-75°)., Conclusions: When reconstructing clasped thumbs, surgeons should explore the presence of APL abnormalities. Release and centralization of the APL can improve thumb position and function. This technique may avoid the need for extra-anatomical tendon transfer in patients with clasped thumb., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

We experienced an atypical case of radial longitudinal deficiency that did not fit into any classifications, including Blauth. The patient had a bilateral hypoplastic thumb, in which the index and middle fingers were missing in the right hand. We performed surgeries in four stages: centralization of the right hand, opponensplasty of the right thumb, opponensplasty of the left thumb, and distraction lengthening of the right ulnar. Twenty-five years after the initial treatment, the patient was satisfied with the treatment and had no significant difficulty with activities of daily living., (© 2024 Japanese Teratology Society.)

This systematic review analyses the literature for long-term outcomes of index finger pollicization. This review includes all seven studies that reported outcomes of index finger pollicization for congenital thumb aplasia or hypoplasia for qualitative review. The seven studies included 108 index finger pollicizations with 54% male children. The studies did not describe the preoperative quality and function of the transposed index finger. Grip strength was in the range of 52%-76% of the contralateral hand. Lateral pinch and key grip strength were also approximately 50% of the contralateral hand. The main drawback of the collective literature is the lack of homogeneity of results and a standardized protocol for reporting postoperative outcomes. These factors need to be addressed to compare the long-term results of pollicizations accurately., Competing Interests: Declaration of conflicting interestsThe authors declare no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

BACKGROUND Congenital hypoplasia of the thumb type IV, also known as floating thumb, is a condition in which 2 small phalanges are attached to the hand with a thin skin bridge. Surgical management options for this condition vary from amputation to flap reconstruction. MATERIAL AND METHODS This retrospective study analyzed 11 infants with congenital hypoplasia of the thumb type IV who underwent surgical reconstruction using a modified vascularized polydactylous hallux flap. The study included 6 male and 5 female infants, aged 6 to 24 months. Functional evaluations and radiographic studies were conducted postoperatively. RESULTS All 11 patients underwent the complete surgical protocol. Successful vascular and nerve anastomoses were performed during the initial procedure, ensuring sufficient blood supply and neural connectivity to the transferred toes. The second operation showed promising outcomes, including improvements in thumb opposition, grasp strength, and overall function. Postoperative assessments demonstrated satisfactory radiographic alignment and no major complications during the follow-up period. CONCLUSIONS The modified vascularized polydactylous hallux flap reconstruction is a viable surgical option for managing congenital hypoplasia of the thumb type IV in infants. This technique effectively restores thumb opposition, grasp strength, and overall hand function, with satisfactory radiographic alignment and minimal complications. The study findings support the efficacy and safety of this surgical approach in addressing this rare congenital anomaly.

Background: Townes-Brocks syndrome (TBS) is a rare genetic disorder characterized by imperforate anus, dysplastic ears, thumb malformations, and other abnormalities. Previous studies have revealed that mutations in the SALL1 gene can disrupt normal development, resulting in the characteristic features of Townes-Brocks syndrome. Spalt-like transcription factors (SALLs) are highly conserved proteins that play important roles in various cellular processes, including embryonic development, cell differentiation, and cell survival. Over 400 different variants or mutations have been reported in the SALL1 gene in individuals with TBS. Most of these variants lead to the formation of premature termination codons (PTCs), also known as nonsense mutations. The majority of these PTCs occur in a specific region of the SALL1 gene called the "hotspot region", which is particularly susceptible to mutation., Methods: In this study, we conducted whole-exome sequencing on a three-generation Chinese family with anorectal malformations., Results: We identified a novel heterozygous mutation (chr16:51175376:c.757 C > T p.Gln253*) in the SALL1 gene. Molecular analysis revealed a heterozygous C to T transition at nucleotide position 757 in exon 2 of the SALL1 (NM_002968) gene. This mutation is predicted to result in the substitution of the Gln253 codon with a premature stop codon (p.Gln253*). The glutamine-rich domain forms a long alpha helix, enabling the mutant protein to interact with the wild-type SALL1 protein. This interaction may result in steric hindrance effects on the wild-type SALL1 protein., Conclusions: Our findings have expanded the mutation database of the SALL1 gene, which is significant for genetic counseling and clinical surveillance in the affected family. Furthermore, our study enhances the understanding of Townes-Brocks syndrome and has the potential to improve its diagnosis and treatment., (© 2024. The Author(s).)

The extensor digitorum profundus complex underwent degeneration of the ulnar segments during primate adaptation and evolution. This process resulted in the preservation of only the extensor pollicis longus and extensor indicis in some apes, including humans. Consequently, anatomical variations within the digitorum profundus complex in modern humans have been well-documented, with detailed reports on their frequency and patterns in previous studies. Here, we report an unusual arrangement involving two anomalies in the extensor digitorum profundus complex, identified in a 66-year-old Japanese male cadaver. In this cadaver, two accessory muscles differentiated from both the extensor pollicis longus and extensor indicis. Notably, the latter muscle featured a tendon bifurcating towards both the thumb and index fingers, referred to as the extensor pollicis et indicis communis. Under the extensor retinaculum, the tendon of the accessory extensor pollicis longus passed through an independent compartment, whereas that of the extensor pollicis et indicis communis traversed a compartment shared by the extensor indicis and the extensor digitorum communis. Both muscles were innervated by the posterior interosseous nerve. Previous studies have reported that the accessory slip of the extensor pollicis longus and extensor pollicis et indicis communis appear at frequencies of 0.6% and 0.4-1.4%, respectively. However, to the best of our knowledge, a configuration in which both appear simultaneously has not been reported. The data from this case could provide essential insights into the variations in the extensor digitorum profundus complex in humans and non-human primates., (© 2024. The Author(s), under exclusive licence to Japanese Association of Anatomists.)

This cadaveric study describes a dorsal wrist transverse elliptical cutaneous flap, based on radial artery cutaneous perforators in the region of the snuffbox. The flap was then successfully used in a child with thumb hypoplasia and severe first-web contracture., Competing Interests: Declaration of conflicting interestsThe authors declare no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Pathogenic variants of the KCNH1 gene can cause dominant-inherited Temple-Baraitser/Zimmermann-Laband syndrome with severe mental retardation, seizure, gingival hyperplasia and nail hypoplasia. This study established an induced pluripotent stem cell (iPSC) line using urinary cells from a girl with KCNH1 recurrent/hotspot pathogenic variant c.1070G > A (p.R357Q). The cell identity, pluripotency, karyotypic integrity, absence of reprogramming virus and mycoplasma contamination, and differential potential to three germ layers of the iPSC line, named as ZJUCHi003, were characterized and confirmed. Furthermore, ZJUCHi003-derived neurons manifested slower action potential repolarization process and wider action potential half-width than the normal neurons. This cell line will be useful for investigating the pathogenic mechanisms of KCNH1 variants-associated symptoms, as well as for evaluating novel therapeutic approaches., (© 2024. The Author(s) under exclusive licence to Japan Human Cell Society.)

Background: Townes-Brocks syndrome (TBS) is a rare genetic disorder characterised by multiple malformations. Due to its phenotypic heterogeneity and rarity, diagnosis and recognition of TBS can be challenging and there has been a lack of investigation of patients with atypical TBS in large cohorts and delineation of their phenotypic characteristics., Methods: We screened SALL1 and DACT1 variants using next-generation sequencing in the China Deafness Genetics Consortium (CDGC) cohort enrolling 20 666 unrelated hearing loss (HL) cases. Comprehensive clinical evaluations were conducted on seven members from a three-generation TBS family. Combining data from previously reported cases, we also provided a landscape of phenotypes and genotypes of patients with TBS., Results: We identified five novel and two reported pathogenic/likely pathogenic (P/LP) SALL1 variants from seven families. Audiological features in patients differed in severity and binaural asymmetry. Moreover, previously undocumented malformations in the middle and inner ear were detected in one patient. By comprehensive clinical evaluations, we further provide evidence for the causal relationship between SALL1 variation and certain endocrine abnormalities. Penetrance analysis within familial contexts revealed incomplete penetrance among first-generation patients with TBS and a higher disease burden among their affected offspring., Conclusion: This study presents the first insight of genetic screening for patients with TBS in a large HL cohort. We broadened the phenotypic-genotypic spectrum of TBS and our results supported an underestimated prevalence of TBS. Due to the rarity and phenotypic heterogeneity of rare diseases, broader spectrum molecular tests, especially whole genome sequencing, can improve the situation of underdiagnosis and provide effective recommendations for clinical management., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objectives: Thumb duplication is one of the most challenging pediatric reconstructive hand surgeries. Wassel types II and IV are the most frequent, but also the most complex reconstructions as the duplication arises at the joint level. Ablation and reconstruction, the most widely used technique, aims at achieving a stable, well-aligned, mobile and esthetically acceptable thumb. The paucity of reliable surgical guidelines leads to high rates of suboptimal surgical outcomes. This review evaluated the various reconstruction techniques detailed in the literature and highlighted useful methods to prevent common secondary complications., Methods: A comprehensive PubMed and Embase literature search was made. Inclusion criteria were Wassel type II and/or IV, pediatric patients, and primary or secondary surgeries. Exclusion criteria were Bilhaut-Cloquet reconstruction and its modifications. Techniques were screened, collected and analyzed for the following secondary complications: instability, axial deformity, and contour deformity., Results: Thirty-two articles met the inclusion criteria and were reviewed. Postoperative instability was prevented by tightening the joint capsule by plication, advancement of the volar plate, or reconstruction of the collateral ligaments using a periosteal flap or the double-breasting technique. Axial deformity was prevented by arthroplasty, shaving a triangular portion of the metacarpal head, centralization of eccentric tendons, pulley reconstruction using flexor pollicis longus, or corrective osteotomies of the phalangeal or metacarpal bones using the wedge or oblique techniques. Limited range of motion was prevented by first webspace Z-plasty, and soft-tissue contouring was addressed by planned skin incisions and soft-tissue augmentation. Preoperative, perioperative and postoperative considerations, including splinting, imaging and immobilization, were also described., Conclusion: Despite the ongoing advances and abundant knowledge in reconstructive strategies for thumb duplication, there are few studies that reviewed and analyzed the various reported options. This review provides physicians and trainees with guidance in surgical planning to prevent common secondary complications. Further research should focus on the development of standardized assessment tools, enabling reliable prospective comparative studies on thumb duplication reconstruction., Level of Evidence: IV., (Copyright © 2024 SFCM. Published by Elsevier Masson SAS. All rights reserved.)

This study examined the relationship between osteochondral stability and postoperative deviation at the interphalangeal (IP) joint in Wassel types II and III radial polydactyly. Cases with cartilaginous fusion between the radial distal phalanx and the proximal phalanx were classified as type IIB, while the remaining cases were categorized as type IIA. In conventional surgery, the cartilage was routinely resected on the radial aspect of the proximal phalangeal head, while in the modified procedure, this was preserved to avoid postoperative radial deviation. Postoperatively, there was no significant difference between both procedures in type IIA thumbs regarding IP joint deviation, whereas in type IIB/III thumbs, IP joint deviation was significantly higher in the conventional group (mean 19° [SD 16°]) compared to the modified group (mean 0.8° [SD 4.9°]). Surgeons should exercise caution against excessive cartilage excision to preserve osteochondral stability during procedures, especially for type IIB and III radial polydactylies. Level of evidence : IV., Competing Interests: Declaration of conflicting interestsThe authors declare no potential conflicts of interest with respect to the research, authorship, and publication of this article.

Background: Previous classifications in polydactyly of the thumb were by the level of duplication on radiography. This study aimed to develop a practical algorithm based on physical characteristics for treatment guidelines., Methods: The polydactylies were stratified using four physical characteristics: floating, symmetry, dominant side, and joint angulation/nail size. The algorithm identified the hypoplastic type and then stratified the polydactylies as symmetric and asymmetric. The asymmetric type was divided into ulnar dominant and radial dominant. The symmetric type was divided into adequate type and inadequate type. The prediction of treatments was studied retrospectively by the distribution of surgical procedures in 500 patients with 545 affected thumbs, by the new classification and the Wassel-Flatt classification., Results: Of the 545 polydactylies, 78 (14.5%) were categorized as the hypoplastic type, 369 (67.5%) as the ulnar-dominant type, 8 (1.5%) as the radial-dominant type, 70 (12.8%) as the symmetric adequate nail type, and 20 (3.7%) as the symmetric inadequate type. Treatments were excision and reconstruction in 403 polydactylies (73.9%), simple excision in 135 polydactylies (24.8%), and the Bilhaut-Cloquet procedure, ray amputation, and on-top plasty procedures were only performed in 7 polydactylies (1.3%). The distribution of surgical procedures was distinct among the new classification types and was similar among the Wassel-Flatt types., Conclusions: The new classification stratified polydactylies by physical findings in a stepwise manner. Though surgical technical details are not included, this simple classification is useful for paediatricians and parents to understand how a surgical decision is made., Level of Evidence: Diagnostic Level IV., Competing Interests: Conflict of interest The authors declare that they have no potential conflicts of interest for this study., (Copyright © 2024 Taiwan Pediatric Association. Published by Elsevier B.V. All rights reserved.)

Long-term follow-up after surgical correction of patients with radial polydactyly might reveal unexpected or undesired outcomes that are accentuated by growth. It should be stressed that assessment of outcomes differs considerably by the system used. Preoperative examination can elucidate the underlying pathological anatomy of these anomalies and consequently, these anatomical differences should be corrected as much as possible during the first operation to prevent worse outcomes at long-term follow-up. In various long-term studies, the reoperation rate was in the range of 7%-28%, with the most common reasons being deviation, instability, nail deformity and suboptimal appearance. Most unfavourable results occur during growth and are frequently revealed only at longer-term follow-up. Concentration of care to a few centres is advised since these malformations occur in small numbers and experienced surgeons tend to have better results. Consensus on the used assessment system and multicentred studies are essential in future to better understand how we can prevent reoperations., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

We designed a new method using hemi-longitudinal second metacarpal bone to reconstruct grade-3 hypoplastic thumbs. Seven patients were treated in two stages. In the first stage, the second metacarpal was split longitudinally and transferred to reconstruct the first metacarpal. In the second stage, opponensplasty was performed by transferring the FDS tendon. Bone union was achieved in all cases. All patients could oppose to their middle finger at least. They managed to do daily activities such as writing, eating, using smartphones and so on. This is a useful procedure to preserve a 5-digit hand with good function in treating grade-3 hypoplastic thumbs, with no harm to the foot and no need for vascular anastomosis. LEVEL OF EVIDENCE: IV., (Copyright © 2023. Published by Elsevier Masson SAS.)

Background: To investigate the functional and aesthetic results of a new modified Bilhaut-Cloquet procedure for the treatment of Wassel type III-IV thumb polydactyly., Methods: Thirteen patients with Wassel type III-IV thumb polydactyly who visited the Department of Orthopedics of Hebei Provincial Children's Hospital from 2019 to 2022 were selected. The surgical procedure involved a modified Bilhaut-Cloquet surgery, where two-thirds of the distal part of the dominant finger was retained as the p body of the reconstructed thumb. The triangular bone block of the ablated distal thumb that did not contain the epiphysis and articular cartilage was sutured and fixed, and the neurovascular flap of the ablated distal thumb was used as an augmenting segment of the reconstructed thumb, with the nail bed and nail matrix exquisitely sutured. The evaluation performed according to the Japanese Society for Surgery of the Hand (JSSH) system., Results: All 13 children showed bone healing, no wound infection, nonunion, or deformity healing. None of the children showed a significant reduction in the active and passive mobility of the thumb postoperatively compared with preoperatively. Postoperative evaluation was performed based on the JSSH score, with a mean of 17.15 points (14-19 points), with 11 children rated as excellent and two as good. No severe nail ridges, nail gaps, or nail split deformities of the thumb were observed postoperatively. Postoperative metacarpophalangeal and interphalangeal joint movements were not reduced compared with preoperative movements. All parents were satisfied with the appearance and function of the reconstructed thumb., Conclusion: The modified Bilhaut-Cloquet procedure designed in this study was satisfactory for Wassel type III-IV thumb polydactyly without affecting the stability of the interphalangeal joints and preserving joint mobility. The postoperative thumb has a comparable circumference and nail width and was cosmetically and functionally satisfactory, especially for the asymmetric two thumbs, which achieved favorable results., (© 2024. The Author(s).)

Radial longitudinal deficiency (RLD) is commonly associated with thumb hypoplasia. The association between RLD and radial polydactyly (RP) is uncommon, but case reports or case series have been reported. We report our experience of managing patients with this association. A total of 97 patients with RLD were seen in our department, of which six were children with concomitant RLD and RP. Four children had both RLD and RP in the same limb; of them, three also had RLD in the contralateral limb. The mean age at presentation was 11.6 months. Awareness of this association alerts the clinician to look for RLD in the presence of RP and vice versa. This case series supports recent experimental and clinical evidence that RP and RLD may be part of the same developmental spectrum. Further studies may guide its inclusion as a possible new category in the Oberg-Manske-Tonkin (OMT) classification of congenital upper-limb anomalies. Level of evidence: IV., Competing Interests: Declaration of conflicting interestsThe authors declare no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: The aim of this study was to determine the clinical outcomes of vascularized hemi-metatarsal composite tissue transfer for the reconstruction of type IIIB hypoplastic thumbs., Methods: Twenty-eight patients with type IIIB hypoplastic thumbs treated with vascularized hemi-metatarsal composite tissue transfer were included in this retrospective study with a mean follow-up of 2.4 years. Preoperative digital subtraction angiography was performed to examine the vessel variance. Clinical measures included grip and pinch strength, scar status, and Kapandji thumb opposition score. Subjective Pediatric Outcomes Data Collection Instrument scores and parent satisfaction were also evaluated., Results: Radial arteries were hypoplastic in 82.1% of the cases, and the common palmar digital artery was chosen as the recipient vessel for the tissue transfer. There was no neurovascular complication. The only donor-site complication was a metatarsal fracture that healed with casting. Key pinch and tripod pinch were 29.5% and 45.8% of the normal side, respectively. The mean grip strength was 51.7% of the unaffected side. The mean Kapandji score was 6. The Pediatric Outcomes Data Collection Instrument scores were high for global function; upper extremity function; transfer; and basic mobility, happiness, and comfort. The Vancouver Scar Scale showed an average score of 2.1. All parents were satisfied with the clinical outcomes., Conclusion: Vascularized hemi-metatarsal composite tissue transfer for type IIIB thumb hypoplasia can provide improved subjective outcomes and is a feasible method for the attainment of a five-digit hand., Clinical Question/level of Evidence: Therapeutic, IV., (Copyright © 2023 by the American Society of Plastic Surgeons.)

Triphalangeal thumbs (TPTs) are regularly caused by mutations in the ZRS in LMBR1. Phenotypic variability can be present in TPT-families. However, recent observations suggest an increased occurrence of severe phenotypes in the Dutch TPT-population. Therefore, the aim of this study is to investigate the progression of the clinical severity of TPT-phenotype through generations. Index patients from a Dutch TPT-population were identified. A 105C>G mutation in the ZRS has previously been confirmed in this population. Questionnaires regarding family occurrence and phenotypes were distributed. Subsequently, families were visited to validate the phenotype. Both occurrence and inheritance patterns of the TPT-phenotype were analyzed through multiple generations. One hundred seventy patients with TPT were identified from 11 families. When considering all 132 segregations (parent-to-child transmission), 54% of the segregations produced a stable phenotype, 38% produced a more severe phenotype while only 8% of the phenotype was less severe when compared to the affected parents. Overall, 71% of the index patients had a more severe phenotype compared to their great-grandparent. Although all family members share an identical mutation in the ZRS (105C>G), it does not explain the wide phenotypic range of anomalies. Our observational study provides better estimations for counseling and provides new insights in the long-range regulation of SHH by the ZRS-enhancer. In the current study, we provide evidence that the assumed variability in TPT-phenotype is not random, but in fact it is more likely that the expression becomes more severe in the next generation. Therefore, we observe a pattern that resembles phenotypic anticipation in TPT-families. [ABSTRACT FROM AUTHOR]

Purpose: Resection of the underdeveloped digit and reconstruction of the robust digit is the standard treatment option for preaxial polydactyly of the hand. As an underdeveloped digit, the radial component is usually excised, whereas the ulnar component excision is rarely needed. This study aimed to evaluate the surgical results of ulnar component excision and radial component reconstruction in patients with preaxial polydactyly of the hand., Methods: We retrospectively reviewed the medical records and radiographs of 809 patients (861 thumbs) who underwent surgery for preaxial polydactyly of the hand from November 2006 to June 2018. Among these, 22 (2.6%) thumbs in which the ulnar component was more hypoplastic or had more severe deformities than the radial component were treated with ulnar component excision and radial component reconstruction. The mean follow-up duration was 49 months (range, 12-142 months). We evaluated the Japanese Society for Surgery of the Hand scores and whether the patients were satisfied with the thumb function and appearance at the final follow-up. We also recorded any complications, such as reoperation., Results: The mean Japanese Society for Surgery of the Hand score was 12.8 (range, 5-17). Six patients had poor results, 7 had fair results, and 2 had good results; however, none of the patients had an excellent result. Satisfaction with thumb function and appearance was reported in 11 (50%) and 6 (27%) cases, respectively. Thirteen of 22 (59.1%) cases involved reoperations, and the most common reason for reoperation was interphalangeal joint deviation of the remaining thumb., Conclusions: Ulnar component excision and radial component reconstruction are rare operative choices in preaxial polydactyly of the hand. Surgeons and patients should be aware that a considerable number of patients treated with this method required reoperations and had low clinical outcome scores., Type of Study/ Level of Evidence: Prognostic IV., (Copyright © 2023 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.)

Background: Historically, amputation and pollicization has been the recommended surgical treatment for Blauth type III hypoplastic thumbs. However, due to aesthetic objections or cultural preferences, some parents seek out alternative surgical options. The present study describes a nontraditional technique that preserves and augments the hypoplastic thumb., Methods: Patient charts were retrospectively reviewed to identify patients with Blauth type III hypoplastic thumbs who underwent thumb reconstruction at our institution from 2008 to 2018. The reconstruction procedure involved toe phalanx transfer, staged tendon transfers, and lengthening as needed. Motion was assessed categorically as ability to flex, extend, or oppose the thumb. Functionality was assessed as ability to pinch and grasp with the surgical hand. Patient- or parent-reported improvement in thumb function was also recorded., Results: Of the 13 patients, 100% could flex, extend, and oppose the thumb to some degree. Eleven patients (85%) had functional one-handed grasp, and 9 (69%) had a functional pinch. Eleven patients (85%) reported no functional limitations of the operative hand. Thirteen patients (100%) reported improvement in hand function after surgery as compared to pre-operatively. There were 2 minor complications (15%), both of which resolved after intervention. No patients experienced donor-site morbidity., Conclusions: Reconstruction of Blauth III thumbs is a nontraditional technique that allows for digit retention by salvaging the hypoplastic thumb. In the present study, the majority of patients had functional thumbs and all reported postoperative improvement. Overall, our results suggest that reconstruction is a viable surgical option for Blauth III hypoplastic thumbs.

Purpose of Review: Polydactyly presents with variable extent of duplication and may involve preaxial/radial (hand)/medial (foot), postaxial/ulnar (hand)/lateral (foot) or central duplication. This review will summarize recent advancements in the surgical management of this common entity., Recent Findings: Modifications to classification systems aim to help guide surgical management of polydactyly. Attempts have been made at quantifying preoperative angulation of the duplicated digits to minimize the chance of residual or recurrent deformity after surgical reconstruction. As a result, consideration should be given to the need for soft tissue correction vs. osteotomy to optimize the clinical outcome. On-top plasty is an option that may be beneficial in 'unequal' preaxial polydactyly, where neither duplicate is preferred on its own., Summary: Polydactyly is one of the most common congenital anomalies in the hands and feet. Determination of surgical intervention often begins with classification systems that exist, which primarily separate these into preaxial, postaxial, and central. Referral for surgical consideration is indicated, given the management is often surgical., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: To present a radiographic follow-up study of the use of a nonvascularized iliac crest bone graft as a treatment for modified Blauth type IIIB thumb hypoplasia., Methods: From January 2015 to December 2019, nonvascularized iliac crest bone grafts were used to reconstruct the first metacarpal in 23 cases with type IIIB thumbs. The average follow-up duration was 1.9 years (range 1.0-3.9 years). We evaluated the patients' serial x-rays and measured the width and length changes of the reconstructed first metacarpals., Results: Survival of the graft, judged radiographically, was achieved in 20 cases (20/23, 87%), with an average reduction of 33% in the width of the graft. Shortening of the graft (average 2.3 mm, range 0.1-5.6 mm) was noted in 11 of the 20 cases, and an increase in the length of the graft (average 4.2 mm, range 0.7-8.6 mm) was observed in the other 9. Bone graft failure (3/23, 13%) occurred in 3 cases because of significant bone resorption., Conclusions: For type IIIB thumb hypoplasia, a nonvascularized iliac crest bone graft was a feasible method to reconstruct the first metacarpal, with a 13% risk of graft failure, 33% average reduction in graft width, and 55% reduction in graft length. However, in cultures that value the preservation of a 5-digit hand, this technique may provide an alternative to excision with index pollicization., Type of Study/level of Evidence: Therapeutic IV., (Copyright © 2023 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.)

SALL1 heterozygous pathogenic variants cause Townes-Brocks syndrome (TBS), a condition with variable clinical presentation. The main features are a stenotic or imperforate anus, dysplastic ears, and thumb malformations, and other common concerns are hearing impairments, foot malformations, and renal and heart defects. Most of the pathogenic SALL1 variants are nonsense and frameshift, likely escaping nonsense-mediated mRNA decay and causing disease via a dominant-negative mechanism. Haploinsufficiency may result in mild phenotypes, but only four families with distinct SALL1 deletions have been reported to date, with a few more being of larger size and also affecting neighboring genes. We report on a family with autosomal dominant hearing impairment and mild anal and skeletal anomalies, in whom a novel 350 kb SALL1 deletion, spanning exon 1 and the upstream region, was identified by array comparative genomic hybridization. We review the clinical findings of known individuals with SALL1 deletions and point out that the overall phenotype is milder, especially when compared with individuals who carry the recurrent p.Arg276Ter mutation, but with a possible higher risk of developmental delay. Chromosomal microarray analysis is still a valuable tool in the identification of atypical/mild TBS cases, which are likely underestimated.

A 28-year-old male musical student has been presented with visible inability of active abduction and extension of the thumbs in both hands beyond the neutral position. The student has not been previously diagnosed and claimed no history of trauma or surgical procedures in the area of hands and no family history of such disabilities. The student remained capable of playing on keyboard instruments on high level due to compensation by hyperextension of the interphalangeal joint of both thumbs and showed no increased frequency of the injuries or playing-related disorders. The ultrasound and magnetic resonance imaging showed complete bilateral agenesis of extensor pollicis brevis muscles and was classified as isolated congenital clasped thumb syndrome. Due to the age of the student and the agenesis of the muscles the conservative treatment was deemed inadequate and due to high functionality of the student as a musician and unforeseeable results it might have on a musician's career, surgical treatment has been disadvised.

Background: Macrodactyly is a very rare congenital difference that affects hands and feet with significant developmental and psychological implications. Macrodactyly is attributed to a somatic mutation in PIK3CA, a component of the mTOR pathway-related overgrowth disorders. Other medical conditions have been associated with macrodactyly (e.g., neurofibromatosis and Proteus syndrome). A thorough investigation of the presence of these conditions should be undertaken by the multidisciplinary team. The aim of this study is to summarize the main clinical characteristics and associated conditions, with an emphasis on diagnosis and surgical treatment options., Materials and Methods: We present several clinical cases after a retrospective chart review of macrodactyly cases and a comprehensive literature review., Results: The indications for surgery include peripheral compressive neuropathies (e.g., carpal tunnel syndrome), grotesque enlargement interfering with function, psychosocial distress due to the deformity, and macrodystrophic lipomatosis with proximal upper limb involvement. The main surgical treatment options are categorized as follows: digit reduction (e.g., soft tissue debulking, skeletal shortening/ terminalization, Barsky procedure, and Tsuge technique), limitation of growth (digital nerve stripping and epiphysiodesis), and correction of deviation (wedge or angulation osteotomy, arthrodesis, Millesi procedure for thumb macrodactyly correction, toe-to-hand transfer, ray resection, and combination of bony reduction and soft tissue debulking)., Conclusions: Macrodactyly correction requires surgical experience and an individualized approach. Treatment is primarily surgical; however, efforts are being made to delineate the root cause of macrodactyly and provide nonoperative management., Competing Interests: Declaration of Competing Interest None., (Copyright © 2022 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.)

Rationale: Triphalangeal thumb (TPT) is a rare congenital malformation where the thumb has three phalanges instead of two. Syndactyly is a condition in which children are born with fused or webbed fingers. The combination of TPT, Syndactyly, and thumb duplication is extremely rare, especially when these deformities are combined in one hand., Patient Concerns: Hand abnormalities and polydactyl have been reported in a 1-year-old boy., Diagnosis: A clinical examination reveals two thumb duplications, finger fusion (Syndactyly), and a thumb with three phalanges (TPT). The diagnosis was based on clinical findings and an X-ray image of the hand., Interventions: The Z-plasty method was used to remove the adhesion between the thumb and forefinger, as well as the removal of the medial and distal phalanx of the thumb's medial tip., Outcomes: The patient was followed for 2 months and found him in good health. To authors' knowledge, we described an unusual case from Syria, considered the first in medical history., Lessons Learned: General and plastic surgeons should be aware about this unusual mix of the three abnormalities. The family history must also be carefully investigated to explore the occurrence of hereditary illnesses., Competing Interests: The authors have no funding, ethical statement and conflicts of interest to disclose., (Copyright © 2022 the Author(s). Published by Wolters Kluwer Health, Inc.)

Index pollicization in severe thumb hypoplasia or aplasia in children or for the reconstruction of a mutilated thumb in adults is a rare and technically demanding procedure. Weakness of the new thumb is routinely reported after index pollicization. An inappropriate position of the first dorsal interosseous muscle (FDIM) can partly explain this strength deficit. Here, we report an original anatomical study on FDIM transfer for reanimation of the new thumb's opposition function and its clinical application. An anatomical study was carried out on three upper limbs from fresh, non-embalmed adult cadavers. We demonstrated the feasibility of an FDIM transfer pedicled on the proper FDIM artery and the deep branch of the ulnar nerve. The proximal FDIM insertions were sutured to the lateral border of the flexor retinaculum to recreate the superficial thenar musculature. This procedure was performed on a 52-year-old man who was referred to us with swelling on his hand. We discovered a myxoid inflammatory fibroblastic sarcoma of the thumb that required proximal thumb amputation while preserving the base of the first metacarpal. To our knowledge, this is the first description of FDIM pedicled flap transfer during an index pollicization procedure among an adult population. However, in severe thumb hypoplasia or aplasia cases, this procedure is limited by the size and anatomical variations of the neurovascular structures among a population affected by radial longitudinal deficiency., (Copyright © 2022. Published by Elsevier Masson SAS.)

Although the primary aim of pollicization is to augment function, aesthetic improvement is an important secondary aim. Satisfaction with hand appearance in children with index pollicization for thumb hypoplasia was evaluated in 18 patients at an average of 7.5 years after surgery. Patients and their parents rated the appearance of their operated hand using a 10-point visual analogue scale (VAS). Four independent surgeons and 16 non-surgeon observers also rated the hands after reviewing standardized photographs of each child. The median patient-reported and parent-reported scores were 9 for both groups (IQR: 7-10) with a trend for children 12 years and older, to report lower satisfaction with appearance. The non-surgeon group assessments varied more for a given hand than the surgeons' assessments, though when scores were averaged within these groups for each hand, there was a high degree of correlation between the two groups. Surprisingly, the patient's own assessment showed a trend towards negative correlation when compared with the average rating of the non-surgeon assessors, suggesting that patients' own assessment of their hand's appearance is more affected by subjective factors than the objective physical outcome., Competing Interests: Declaration of Competing Interest None., (Copyright © 2022 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.)

A short thumb with radial angulation causes loss of hand function in patients with Apert syndrome. Although past reports have described various procedures for the correction of the thumb, there has been no consensus on the best procedure. This study aimed to assess the clinical and radiographic results of a surgical technique for the correction of a thumb radial angulation deformity: open-wedge osteotomy using a bone-graft substitute. Ten patients (18 thumbs) who underwent open-wedge osteotomy on the proximal phalange using a bone-graft substitute were evaluated retrospectively. The open-wedge osteotomies had been performed at the center of the proximal phalanx. Thumb radial angles and thumb lengths were measured on radiographs, and the clinical results were investigated, including bone union and complications. The median patient age at the time of surgery was 5.8 years, and the average follow-up period was 6.7 years. The average thumb radial angle was 57.3° preoperatively, 6.5° immediately postoperatively, and 19.8° at the most recent follow-up. The average thumb length was 12.1 mm preoperatively, 18.1 mm immediately postoperatively, and 22.3 mm at the most recent follow-up, indicating an extension effect of more than 50% immediately postoperatively. In all cases, the artificial bone had been absorbed and developed into autologous bone, and there were no complications such as infection and skin necrosis. These findings suggest that open-wedge osteotomy with an artificial bone substitute is simple and effective for treating radial-angulation deformities in patients with Apert syndrome. Level of evidence: Level IV - retrospective case series., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

In this case report, we describe an adult patient with bilateral congenital absence of the m. flexor pollicis longus (FPL) without any other anomalies or thenar atrophy. The FPL muscle acts to flex the thumb and is innervated by the anterior interosseous nerve. Impaired function of the FPL muscle may have several causes. A bilateral anomaly of the FPL tendon is a rare phenomenon, with only a few cases having been reported. This case report does not only demonstrate the diagnosis of bilateral FPL tendon anomaly by physical examination and magnetic resonance imaging, it also includes the embryological development of the FPL muscle and tendon.

Background: Preaxial or radial polydactyly is one of the most common hand congenital anomalies in newborns. Contemporary reconstruction methods include ligament reconstruction, excision of the polydactylous thumb, osteotomy, and other surgical techniques according to the type of polydactyly. The purpose of this study was to report mid-term to long-term reconstruction results for thumb (radial) polydactyly., Methods: We retrospectively reviewed the medical records of patients who underwent reconstruction surgery for preaxial polydactyly. Clinical outcomes, including the range of motion (ROM), pain, and complications, were evaluated. We assessed the final radiographs of the reconstructed thumb to identify the potential development of arthritis or other remaining deformities. After excluding cases without a simple radiograph and cases with a short follow-up period of fewer than 5 years, 26 thumbs were included. The surgical technique followed including excision of polydactylout thumb was tailored to the type of polydactyly. If the nail size of the thumbs was similar, the Bilhaut-Cloquet method was preferred., Results: The mean age of the patients at the surgery and final follow-up was 14.9 months (range: 8 to 30 mo) and 11.9 years (range: 5.8 to 19.3 y), respectively. The mean follow-up was 128.8 months years (range: 60 to 219 mo), and the mean ROM of the thumb was 32.7 and 57.5 degrees in the distal interphalangeal joint (DIP) and metacarpophalangeal (MP) joint, respectively. Ulnar or radial side instability was prominent in 7 patients in the involved joints (26.9%). One patient underwent interphalangeal (IP) fusion for extension lag with pain. The radiologic evaluation revealed that 2 patients developed radiographic evidence of IP joint arthritis (7.7%). Radial deviation of the MP or IP joint existed in 13 cases (range: 5 to 40 degrees) (50.0%), and ulnar deviation of the MP or IP joint existed in 2 cases (range: 19 to 20 degrees) (7.7%)., Conclusions: In mid-term to long-term experience, sequelae such as joint instability, joint stiffness, and remaining deformity cannot be neglected. An unstable MP joint may result if the DIP joint remains stiff or has a lower ROM., Level of Evidence: Level IV-therapeutic studies., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

The primary cilium is a non-motile sensory organelle that extends from the surface of most vertebrate cells and transduces signals regulating proliferation, differentiation, and migration. Primary cilia dysfunctions have been observed in cancer and in a group of heterogeneous disorders called ciliopathies, characterized by renal and liver cysts, skeleton and limb abnormalities, retinal degeneration, intellectual disability, ataxia, and heart disease and, recently, in autism spectrum disorder, schizophrenia, and epilepsy. The potassium voltage-gated channel subfamily H member 1 (KCNH1) gene encodes a member of the EAG (ether-à-go-go) family, which controls potassium flux regulating resting membrane potential in both excitable and non-excitable cells and is involved in intracellular signaling, cell proliferation, and tumorigenesis. KCNH1 missense variants have been associated with syndromic neurodevelopmental disorders, including Zimmermann-Laband syndrome 1 (ZLS1, MIM #135500), Temple-Baraitser syndrome (TMBTS, MIM #611816), and, recently, with milder phenotypes as epilepsy. In this work, we provide evidence that KCNH1 localizes at the base of the cilium in pre-ciliary vesicles and ciliary pocket of human dermal fibroblasts and retinal pigment epithelial (hTERT RPE1) cells and that the pathogenic missense variants (L352V and R330Q; NP_002229.1) perturb cilia morphology, assembly/disassembly, and Sonic Hedgehog signaling, disclosing a multifaceted role of the protein. The study of KCNH1 localization, its functions related to primary cilia, and the alterations introduced by mutations in ciliogenesis, cell cycle coordination, cilium morphology, and cilia signaling pathways could help elucidate the molecular mechanisms underlying neurological phenotypes and neurodevelopmental disorders not considered as classical ciliopathies but for which a significant role of primary cilia is emerging., (© 2022. The Author(s).)

We analysed the spectrum of congenital hand differences in a cohort of patients with Fanconi anaemia (FA). Data of 48 FA patients at the National Cancer Institute were reviewed focusing on age at diagnosis, type and severity of limb difference and any potential association with other known clinical anomalies that are part of the FA phenotype, specifically VACTERL-H and PHENOS. Twenty-eight patients had an upper limb difference, which always included thumb hypoplasia. Twenty-three patients had bilateral upper limb differences, including varying combinations and severities of thumb hypoplasia, radial dysplasia and thumb duplication. Patients with a limb difference were diagnosed at a younger age (<2 years: 15/28 with limb anomaly versus 4/20 without a limb anomaly). However, 7/28 with limb anomalies, usually thumb hypoplasia, were not diagnosed until after 6 years of age. This study demonstrates the broad spectrum of radial ray anomalies within the FA phenotype along with the possibility of either unilateral or bilateral upper limb differences and adds further merit to consideration of screening for FA in all cases of radial ray anomaly. Level of evidence: II.

Background: The purpose of this research is to study the modified surgical effect of Wassel type III radial polydactyly thumbs of equal or nearly equal size treated., Methods: The study sample consisted of 12 reconstructed cases of Wassel type III radial polydactyly. The proximal phalanx was unequally combined by the curvature osteotomy and aligned the articular surface, and the distal phalanx was symmetrically combined. A fragment bone was filled in the depression of the distal phalanx to correct nail curvature and prevent seagull deformities. Twelve cases were available for assessment using an evaluation form on the Japanese Society for Surgery of the Hand., Results: An average functional point was 13.75 points (maximum 14 points). The interphalangeal joint motion was reduced, but this joint was stable in all cases. The cosmetic score was averaged 3.6 (maximum 4 points), and most parents were satisfied with the postoperative appearance and functional results., Conclusion: Our modification of Bihaut-Cloquet procedure is an effective way to provide a well-functioning thumb for Wassel type III radial polydactyly thumbs., Level of Evidence: Level IV., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

With the same clinical picture, different pathological changes must be expected in congenital malformations of the hand. Therefore, knowledge of these pathologies is crucial for planning the surgical approach. The approaches to common malformations are dealt with as examples. These include the double thumb and the syndactyly.In the case of the double thumb with an asymmetrical contour, the result is improved by augmenting parts of the redundant double thumb. In this case, a different incision is required than in simple resection.In the frequently performed syndactyly separations, there are many techniques that have been proven to achieve a good result. But only if principles such as local displacement flap plasty for commissure formation, tension-free wound closure, no longitudinal incisions and no bilateral preparation of a finger are observed here too. If it can be assumed preoperatively that a good surgical result cannot be achieved with the conventional technique of syndactyly separation, pre-treatment using an external fixator for transverse soft tissue distraction is the method of choice.The timing of surgery takes into account not to disturb the motor development of the affected person., Competing Interests: Die Autorinnen/Autoren geben an, dass kein Interessenkonflikt besteht., (Thieme. All rights reserved.)