Limb development genes underlie variation in human fingerprint patterns.

Fingerprints are of long-standing practical and cultural interest, but little is known about the mechanisms that underlie their variation. Using genome-wide scans in Han Chinese cohorts, we identified 18 loci associated with fingerprint type across the digits, including a genetic basis for the long-recognized "pattern-block" correlations among the middle three digits. In particular, we identified a variant near EVI1 that alters regulatory activity and established a role for EVI1 in dermatoglyph patterning in mice. Dynamic EVI1 expression during human development supports its role in shaping the limbs and digits, rather than influencing skin patterning directly. Trans-ethnic meta-analysis identified 43 fingerprint-associated loci, with nearby genes being strongly enriched for general limb development pathways. We also found that fingerprint patterns were genetically correlated with hand proportions. Taken together, these findings support the key role of limb development genes in influencing the outcome of fingerprint patterning.

Toe stimulation improves tactile perception of the genitals.

The human body is represented in a topographic pattern in the primary somatosensory cortex (S1), and genital representation is displaced below the toe representation. However, the relationship between the representation of the genitals and toe in S1 remains unclear. In this study, tactile stimulation was applied to the big toe in healthy subjects to observe changes in tactile acuity in the unstimulated genital area, abdomen, and metacarpal dorsal. Then tactile stimulation was applied to the right abdomen and metacarpal dorsal to observe changes in tactile acuity in bilateral genitals. The results revealed that tactile stimulation of the big toe led to a reduction in the 2-point discrimination threshold (2PDT) not only in the stimulated big toe but also in the bilateral unstimulated genitals, whereas the bilateral abdomen and metacarpal dorsal threshold remained unchanged. On the other hand, tactile stimulation of the abdomen and metacarpal dorsal did not elicit 2-point discrimination threshold changes in the bilateral genitals. Cortical and subcortical mechanisms have been proposed to account for the findings. One explanation involves the intracortical interaction between 2 adjacent representations. Another possible explanation is that the information content of a specific body part is broadly distributed across the S1. Moreover, exploring the links between human behaviors and changes in the cerebral cortex is of significant importance.

A novel homozygous FAM92A gene (CIBAR1) variant further confirms its association with non-syndromic postaxial polydactyly type A9 (PAPA9).

Polydactyly is a very common digit anomaly, having extra digits in hands and/or toes. Non-syndromic polydactyly in both autosomal dominant and autosomal recessive forms are caused by disease-causing variants in several genes, including GLI1, GLI3, ZNF141, FAM92A, IQCE, KIAA0825, MIPOL1, STKLD1, PITX1, and DACH1. Whole exome sequencing (WES) followed by bi-directional Sanger sequencing was performed for the single affected individual (II-1) of the family to reveal the disease causative variant/gene. 3D protein modeling and structural molecular docking was performed to determine the effect of the identified mutation on the overall protein structure. WES revealed a novel biallelic missense variant (c.472G>C; p.Ala158Pro) in exon 6 of the FAM92A gene. The identified variant segregated perfectly with the disease phenotype using Sanger sequencing. Furthermore, Insilco analysis revealed that the variant significantly changes the protein secondary structure, and substantially impact the stability of FAM92A. We report the second FAM92A disease-causing mutation associated with recessive non-syndromic postaxial polydactyly. The data further confirms the contribution of FAM92A in limb development and patterning.

Ophthalmic manifestations of Czech dysplasia.

Czech dysplasia is an autosomal dominant type 2 collagenopathy that is caused by heterozygosity for the recurrent p.(Arg275Cys) COL2A1 variant. Affected individuals usually present with skeletal abnormalities such as metatarsal hypoplasia of the third and fourth toes and early-onset arthropathy, as well as hearing loss. To date, no ophthalmic findings have been reported in patients with Czech dysplasia even though COL2A1 has been implicated in other ocular conditions such as type 1 Stickler syndrome. For the first time, we report the ocular findings in four families with Czech dysplasia, including type 1 vitreous anomaly, hypoplastic vitreous, retinal tears, and significant refractive error. These novel ocular findings expand the phenotype associated with Czech dysplasia and may aid clinicians as an additional diagnostic feature. Patients with congenital abnormalities of vitreous gel architecture have an increased risk of retinal detachment, and as such, patients may benefit from prophylaxis. Considering that many of the patients did not report any ocular symptoms, vitreous phenotyping is of key importance in identifying the need for counseling with regard to prophylaxis.

Greater prefrontal activation during sitting toe tapping predicts severer freezing of gait in Parkinson's disease: an fNIRS study.

OBJECTIVE: Previous studies have revealed that, compared with Parkinson's disease (PD) patients without freezing of gait (FoG), the ones with FoG showed greater prefrontal activation while doing lower-limb movements involving standing, walking and turning, which require both locomotor and balance control. However, the relation between FoG and pure locomotor control as well as its underlying mechanism remain unclear. METHODS: A total of 56 PD subjects were recruited and allocated to PD-FoG and PD-noFoG subgroups, and 34 age-matched heathy adults were included as heathy control (HC). Functional near-infrared spectroscopy was used to measure their prefrontal activation in a sitting lower-limb movement task, wherein subjects were asked to sit and tap their right toes as big and as fast as possible. RESULTS: Result of one-way ANOVA (Group: PD-FoG vs. PD-noFoG vs. HC) revealed greater activation in the right prefrontal cortex in the PD-FoG group than in the other 2 groups. Linear mixed-effects model showed consistent result. Furthermore, the right prefrontal activation positively correlated with the severity of FoG symptoms in PD-FoG patients. CONCLUSION: These findings suggested that PD patients with FoG require additional cognitive resources to compensate their damaged automaticity in locomotor control, which is more pronounced in severe FoG patients than milder ones.

Toe-brachial index and toe systolic blood pressure for the diagnosis of peripheral arterial disease.

BACKGROUND: Peripheral arterial disease (PAD) of the lower limbs is caused by atherosclerotic occlusive disease in which narrowing of arteries reduces blood flow to the lower limbs. PAD is common; it is estimated to affect 236 million individuals worldwide. Advanced age, smoking, hypertension, diabetes and concomitant cardiovascular disease are common factors associated with increased risk of PAD. Complications of PAD can include claudication pain, rest pain, wounds, gangrene, amputation and increased cardiovascular morbidity and mortality. It is therefore clinically important to use diagnostic tests that accurately identify PAD. Accurate and timely detection of PAD allows clinicians to implement appropriate risk management strategies to prevent complications, slow progression or intervene when indicated. Toe-brachial index (TBI) and toe systolic blood pressure (TSBP) are amongst a suite of non-invasive bedside tests used to detect PAD. Both TBI and TSBP are commonly utilised by a variety of clinicians in different settings, therefore a systematic review and meta-analysis of their diagnostic accuracy is warranted and highly relevant to inform clinical practice. OBJECTIVES: To (1) estimate the accuracy of TSBP and TBI for the diagnosis of PAD in the lower extremities at different cut-off values for test positivity in populations at risk of PAD, and (2) compare the accuracy of TBI and TSBP for the diagnosis of PAD in the lower extremities. Secondary objectives were to investigate several possible sources of heterogeneity in test accuracy, including the following: patient group tested (people with type 1 or type 2 diabetes, people with renal disease and general population), type of equipment used, positivity threshold and type of reference standard. SEARCH METHODS: The Cochrane Vascular Information Specialist searched the MEDLINE, Embase, CINAHL, Web of Science, LILACS, Zetoc and DARE databases and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 27 February 2024. SELECTION CRITERIA: We included diagnostic case-control, cross-sectional, prospective and retrospective studies in which all participants had either a TSBP or TBI measurement plus a validated method of vascular diagnostic imaging for PAD. We needed to be able to cross-tabulate (2 x 2 table) results of the index test and the reference standard to include a study. To be included, study populations had to be adults aged 18 years and over. We included studies of symptomatic and asymptomatic participants. Studies had to use TSBP and TBI (also called toe-brachial pressure index (TBPI)), either individually, or in addition to other non-invasive tests as index tests to diagnose PAD in individuals with suspected disease. We included data collected by photoplethysmography, laser Doppler, continuous wave Doppler, sphygmomanometers (both manual and aneroid) and manual or automated digital equipment. DATA COLLECTION AND ANALYSIS: Two review authors independently completed data extraction using a standardised form. We extracted data to populate 2 x 2 contingency tables when available (true positives, true negatives, false positives, false negatives). Where data were not available to enable statistical analysis, we contacted study authors directly. Two review authors working independently undertook quality assessment using QUADAS-2, with disagreements resolved by a third review author. We incorporated two additional questions into the quality appraisal to aid our understanding of the conduct of studies and make appropriate judgements about risk of bias and applicability. MAIN RESULTS: Eighteen studies met the inclusion criteria; 13 evaluated TBI only, one evaluated TSBP only and four evaluated both TBI and TSBP. Thirteen of the studies used colour duplex ultrasound (CDU) as a reference standard, two used computed tomography angiography (CTA), one used multi-detector row tomography (MDCT), one used angiography and one used a combination of CDU, CTA and angiography. TBI was investigated in 1927 participants and 2550 limbs. TSBP was investigated in 701 participants, of which 701 limbs had TSBP measured. Studies were generally of low methodological quality, with poor reporting of participant recruitment in regard to consecutive or random sampling, and poor reporting of blinding between index test and reference standard, as well as timing between index test and reference standard. The certainty of evidence according to GRADE for most studies was very low. AUTHORS' CONCLUSIONS: Whilst a small number of diagnostic test accuracy studies have been completed for TBI and TSBP to identify PAD, the overall methodological quality was low, with most studies providing a very low certainty of evidence. The evidence base to support the use of TBI and TSBP to identify PAD is therefore limited. Whilst both TBI and TSBP are used extensively clinically, the overall diagnostic performance of these tests remains uncertain. Future research using robust methods and clear reporting is warranted to comprehensively determine the diagnostic test accuracy of the TBI and TSBP for identification of PAD with greater certainty. However, conducting such research where some of the reference tests are invasive and only clinically indicated in populations with known PAD is challenging.

Whole genome resequencing reveals candidate genes for postaxial polydactyly in Large White pigs.

Polydactyly is a genetic abnormality that affects both pig welfare and industry profits. Despite efforts to explore the genetic basis of pig polydactyly, progress remains limited. In this study, we analyzed a group of Large White pigs with postaxial polydactyly, including 29 cases and 79 controls from 24 families. High-depth sequencing was performed on 20 pigs, while low-depth sequencing was improved through imputation for the remaining pigs. A genome-wide association study (GWAS) and genetic differentiation were conducted using the resequencing dataset, resulting in the identification of 48 significantly associated SNPs and 27 candidate regions. The genetic differentiation regions on chromosomes 5 and 18, which harbored GWAS-identified SNPs, were delineated as confidence regions. The confidence region at Chr18: 1.850-1.925 Mb covers the fifth intron of LMBR1, a gene that contains an important regulatory element for SHH, known as ZRS. Mutations in this ZRS have been found to cause polydactyly in animals and humans. Therefore, we propose LMBR1 as a prospective candidate gene for postaxial polydactyly. These findings emphasize the importance of exploring the role of ZRS within LMBR1 in the pathogenesis of polydactyly in pigs.

Evaluation of the Recurrence Rate of Ingrown Toenail After a 45-Second Matrix Cauterization With Phenol.

INTRODUCTION: Ingrown toenail is a very common nail disorder, and partial matricectomy by phenolization is considered the most effective treatment technique. However, the contact time of the phenol with the nail matrix remains debatable. OBJECTIVE: To evaluate the recurrence rate of ingrown toenail after partial matricectomy by phenol for 45 seconds. METHODS: A total of 1,460 surgeries were performed, with a photographic record of 802 pictures for a period of 6 months. The presence of any nail spicule or sign of ingrowth during follow-up was considered a recurrence. RESULTS: A total of 802 surgeries were evaluated, with the most affected nails being the right (49.3%) and left (48%) big toes and most frequently the lateral fold (54.5%). The recurrence rate was 0.75% at 3 months and 1.87% at 6 months, and the medial nail fold had a higher recurrence rate than the lateral nail fold. CONCLUSION: Forty-five seconds of contact time of 88% phenol with the nail matrix was enough and effective, resulting in low recurrence rates. Prospective studies are needed to better assess postoperative morbidity.

Detecting Toe-Off and Initial Contact in Real-Time With Self-Adapting Thresholds.

This research introduces an adaptive control algorithm designed to determine gait phase in real-time using an inertial measurement unit (IMU) affixed to the shank. Focusing on detecting specific gait events, primarily initial contact (IC) and toe-off (TO), the algorithm utilizes dynamic thresholds and ratios that facilitate accurate event determination adaptively across a range of walking speeds. Built-in safety checks further ensure precision and minimize false detections. We validated the algorithm with eight participants walking at varying speeds. The algorithm demonstrated promising results in detecting IC and TO events with mean lead of 8.95 ms and 4.42 ms and detection success rate of 100% and 99.72%, respectively. These results are consistent with benchmarks from established algorithms (Hanlon and Anderson, 2009, "Real-Time Gait Event Detection Using Wearable Sensors," Gait Posture, 30(4), pp. 523-527; Maqbool et al., 2017, "A Real-Time Gait Event Detection for Lower Limb Prosthesis Control and Evaluation," IEEE Trans. Neural Syst. Rehabil. Eng.: Publ. IEEE Eng. Med. Biol. Soc., 25(9), pp. 1500-1509). Moreover, the algorithm's self-adaptive nature ensures it can be used in scenarios of varying movement, offering a promising solution for real-time gait phase detection.

Repair of distal finger soft-tissue defects with free fibular great toe neurovascular flaps.

BACKGROUND: This work aimed to investigate the change in fingerprint depth and the recovery rule of fingerprint biological recognition function after repairing finger abdominal defects and rebuilding fingerprint with a free flap. METHOD: From April 2018 to March 2023, we collected a total of 43 cases of repairing finger pulp defects using the free flap of the fibular side of the great toe with the digital nerve. After surgery, irregular follow-up visits were conducted to observe fingerprint clarity, perform the ninhydrin test or detect visible sweating with the naked eye. We recorded fingerprint clarity, nail shape, two-point discrimination, cold perception, warm perception and fingerprint recognition using smartphones. The reconstruction process of the repaired finger was recorded to understand the changes in various observation indicators and their relationship with the depth of the fingerprint. The correlation between fingerprint depth and neural repair was determined, and the process of fingerprint biological recognition function repair was elucidated. RESULT: All flaps survived, and we observed various manifestations in different stages of nerve recovery. The reconstructed fingerprint had a clear fuzzy process, and the depth changes of the fingerprint were consistent with the changes in the biological recognition function curve. CONCLUSION: The free flap with the digital nerve is used to repair finger pulp defects. The reconstructed fingerprint has a biological recognition function, and the depth of the fingerprint is correlated with the process of nerve repair. The fingerprint morphology has a dynamic recovery process, and it can reach a stable state after 6-8 months.

Refinement of Surgery for Postaxial Polysyndactyly of the Toes: Esthetic Outcome in Japanese Feet.

PURPOSE: Treatment for polysyndactyly of the toes aims at cosmetic improvement but the lateroplantar rotation of the new fifth toe remains challenging. This study evaluated our novel surgical procedure for postaxial polysyndactyly of the toes. MATERIALS AND METHODS: Patients with postaxial polysyndactyly involving the fourth, fifth, and sixth toes treated in 2007 to 2017 with a minimum follow-up duration of 1 year were retrospectively investigated. Our aims of surgery for this condition were to avoid excessive lateroplantar rotation of the new fifth toe by using a proximally elongated plantar "shark-fin flap" and to make the tip of this toe appear to be naturally pointing inward by using the dog-ear component of the flap on the tip of the toe. The excess skin of the shark-fin flap was grafted onto the lateral surface of the fourth toe. Lateroplantar rotation of the fifth toe in these patients was compared with that in photographs of the feet of 96 normal 4-year-old children. RESULTS: A total of 11 feet in 10 patients (6 male, 4 female; mean age 1.3 years) were analyzed. Syndactyly between the fourth and fifth toes was complete in 3 feet, incomplete at the level of the distal interphalangeal joint of the fifth toe in 5, and incomplete at the level of the proximal interphalangeal joint of the fifth toe in 3. Lateroplantar rotation of the fifth toe, evaluated by the mean angle between 2 intersecting lines extending from the proximal nail fold of the third and fifth toes, was 25 ± 10° in normal feet and 0 ± 12° in operated feet with polysyndactyly. The absolute left-right difference in this angle was 7 ± 5° in normal children and 22 ± 12° in patients with polysyndactyly. Valgus deformity of the new fifth toe improved in all patients during a mean postoperative follow-up of 3.8 years. CONCLUSIONS: Using our procedure, no excessive lateroplantar rotation has been observed when the tip of the fifth toe is inclined inward using a dog-ear flap component. This procedure could be useful in patients in whom the cosmetic outcome is a priority.

Core and cluster or head to toe?: a comparison of two types of curricula for teaching physical examination skills to preclinical medical students.

BACKGROUND: Despite the central importance of physical examination (PE) skills to patient evaluation, early trainees struggle with its correct application and interpretation. This struggle may reflect the instructional strategies of PE courses which have largely ignored the clinical reasoning necessary to accurately apply these skills. The "core + cluster" (C + C) is a recent approach to teaching PE to clerkship-level medical students that combines a basic 'core' exam with 'cluster' based on the student's hypothesis about their patient's clinical presentation. Our institution developed a novel C + C curriculum to teach PE to preclinical students. We aimed to assess the impact of this new curriculum on students' clinical skills and course evaluations in comparison to the traditional "head-to-toe" approach we'd used previously. METHODS: This was a retrospective study comparing two consecutive medical school cohorts exposed to the new (C + C) and prior (HTT) curricula respectively. We studied two complete cohorts of first-year medical students at our institution who matriculated in 2014 and 2015. The 2014 cohort received PE training via an HTT approach. The 2015 cohort received PE training via a C + C approach. Outcomes included performance scores on a statewide clinical performance exam (CPX) and student course evaluations. RESULTS: We found no statistically significant difference in mean CPX scores between the two cohorts. However, student course ratings were significantly higher in the C + C cohort and students rated the C + C format as highly useful in clinical encounters. CONCLUSIONS: The C + C curriculum appears to be as effective a method of teaching PE to preclinical students as the HTT approach and is better received by students. We believe that this approach more appropriately reflects the way PE is used in clinical encounters and may help students with diagnostic hypothesis generation.

Application of Artificial Dermis Combined With a Medial Flap From the Second Toe to Repair Degloving Injury of the Fingertip.

There is no standard technique for repairing degloving injuries of the fingertip. Nail bed flap transplantation is a common surgical technique to address this injury, but this procedure inevitably damages the donor site in the toe. This article describes a surgical technique that can restore the appearance of the injured fingernail and preserve the length and function of the injured finger without damaging the toenail.

Health-related Quality of Life in Idiopathic Toe Walkers: A Multicenter Prospective Cross-sectional Study.

OBJECTIVE: Despite idiopathic toe walking (ITW) being a significant source of stress and anxiety for children and parents alike, little is known about the effect on health-related quality of life (HRQoL). The primary research question for this study was "Is ITW associated with impaired HRQoL, and is the degree of equinus contracture related to the degree of impairment?" METHODS: Twelve pediatric orthopaedic centers across the United Kingdom participated in this prospective, cross-sectional observational study of children younger than 18 years with ITW. Data were collected between May 2022 and July 2022. Using a standardized, piloted proforma, data collected included: demographics, toe-walking duration, passive ankle range of motion (Silfverskiold test), associated autism spectrum disorder or attention deficit hyperactivity disorder, previous and planned treatments, and Oxford Ankle Foot Questionnaire for Children scores. Domain scores were compared with a healthy control group and correlation was made to plantarflexion contracture using standard nonparametric statistical methods. RESULTS: Data were collected from 157 children. Significant reductions in physical, school and play, and emotional domain scores were noted compared with healthy controls. A significant moderate correlation was noted between passive ankle dorsiflexion and physical domain scores. There were no significant differences in Oxford Ankle Foot Questionnaire for Children scores among patient groups by treatment. CONCLUSIONS: ITW in children is associated with an impairment in HRQoL, not only across the physical domain but also the school and play and emotional domains. The more severe the equinus contracture, the worse the physical domain scores. LEVEL OF EVIDENCE: Level II-prospective cross-sectional observational study.

MRI of the Spine in Patients who Toe Walk: Is There a Role?

BACKGROUND: Little is known about the prevalence of intraspinal pathology in children who toe walk, but magnetic resonance imaging (MRI) may be part of the diagnostic workup. The purpose of this study was to examine the role of MRI for children who toe walk with a focus on the rate of positive findings and associated neurosurgical interventions performed for children with said MRI findings. METHODS: A single-center tertiary hospital database was queried to identify a cohort of 118 subjects with a diagnosis of toe walking who underwent spinal MRI during a 5-year period. Patient and MRI characteristics were summarized and compared between subjects with a major abnormality, minor abnormality, or no abnormality on MRI using multivariable logistic regression. Major MRI abnormalities included those with a clear spinal etiology, such as fatty filum, tethered cord, syrinx, and Chiari malformation, while minor abnormalities had unclear associations with toe walking. RESULTS: The most common primary indications for MRI were failure to improve with conservative treatment, severe contracture, and abnormal reflexes. The prevalence of major MRI abnormalities was 25% (30/118), minor MRI abnormalities was 19% (22/118), and normal MRI was 56% (66/118). Patients with delayed onset of toe walking were significantly more likely to have a major abnormality on MRI ( P =0.009). The presence of abnormal reflexes, severe contracture, back pain, bladder incontinence, and failure to improve with conservative treatment were not significantly associated with an increased likelihood of major abnormality on MRI. Twenty-nine (25%) subjects underwent tendon lengthening, and 5 (4%) underwent neurosurgical intervention, the most frequent of which was detethering and sectioning of fatty filum. CONCLUSIONS: Spinal MRI in patients who toe walk has a high rate of major positive findings, some of which require neurosurgical intervention. The most significant predictor of intraspinal pathology was the late onset of toe walking after the child had initiated walking. MRI of the spine should be considered by pediatric orthopedic surgeons in patients with toe walking who present late with an abnormal clinical course. LEVEL OF EVIDENCE: Level III Retrospective Comparative Study.

Immediate foot reconstruction and revascularization of toes using an interposition superficial circumflex iliac artery perforator flow-through flap: A case report.

Foot injuries, particularly degloving injuries, can lead to segmental loss of neurovascular structures in the toes, making simultaneous reconstruction of both the foot and toes challenging. This case report presents a technique using the superficial circumflex iliac artery perforator (SCIP) flap for immediate reconstruction of the dorsal foot and revascularization of multiple toes. A 28-year-old man suffered a degloving injury on the dorsum of his foot resulting in a 9 × 6cm skin defect, open fracture dislocations, exposure of tendons, and neurovascular injury, which included a 6-7.5 cm segmental defect of the vessels supplying the first, second, and third toes leaving all three toes ischemic. Immediate reconstruction was performed by harvesting a 12.5 × 5cm SCIP flap including both the superficial and deep branches and incorporating the superficial inferior epigastric vein (SIEV). The SCIP deep branch was used to revascularize the third and second toes and the SIEV vein graft used for the first toe. The patient recovered well, no complications were observed at the 2-year follow-up, preserving all three toes and regaining mobility. The use of the SCIP flap as a flow-through flap provides thin skin flap cover, good vessel caliber size match with digital vessels and reduces the need for vein grafts from distant sites improving surgical efficiency. These attributes make the flow-through interposition SCIP flap an excellent choice for reconstructing foot defects and revascularizing toes. We report this case to demonstrate the utility of the SCIP flap in immediate soft tissue cover and digit revascularization.

Plantar intermetatarsal perforator flap for first web skin-graftless syndactyly release: Anatomical study and clinical application.

INTRODUCTION: Foot-syndactyly has long been managed through conventional surgical procedures, each having its own distinct advantages and drawbacks. While these methods, which do not require skin grafts, exhibit a lower incidence of long-term complications, they lead to undesirable scarring on the dorsal side of the foot and reduced patient satisfaction. In this study, we introduce an innovative technique involving an intermetatarsal plantar flap, supported by an anatomical investigation and clinical application. METHODS: Eight freshly preserved lower limbs were injected with colored latex to examine the cutaneous vessels on the plantar surface, a skin-flap was designed in an elliptical shape to address first web conjoined toes. The flap was extended from the center of each affected ray measuring ~30% of the sole's length. Using the mentioned novel approach, a flap was created and dorsally extended with a straight incision to release bilateral simple foot-syndactyly in an 8-year-old child presented with Apert's Syndrome. RESULTS: We identified cutaneous branches originating either from the medial plantar vessels or the lateral proper artery of the hallux. On average, the mean number of cutaneous branches found over the first intermetatarsal web spaces was 5.8 (ranging from 5 to 8) most of them originating from medial plantar vessels with a mean of 5.1 branches (range 4-6) while proper lateral great-toe digital artery provided a mean of 0.6 branches (range 0-2). Intra-operatively, in our patient, advancing the plantar flap ensured complete coverage of the commissure, obviating the necessity for skin grafts. Incisions healed uneventfully and a wide first web was obtained. Over a 15 months follow-up, no complications were observed. CONCLUSIONS: Our findings suggest that the skin-graftless first web release of syndactyly using a plantar intermetatarsal flap is a reliable and straightforward procedure with good cosmetic results, offering a promising alternative to conventional techniques. LEVEL OF EVIDENCE: Therapeutic IV.

Characterization of Great Toe Extension Strength Using ToeScale-A Novel Portable Device.

Great toe strength (GTS) weakness is linked to declines in balance and mobility. Accurately assessing GTS, particularly great toe extension strength (GTES), is often neglected in clinical evaluations due to cumbersome and subjective methods. This study aims to characterize the force development curve output from the ToeScale and examine GTES variations with age, sex, BMI, and grip strength (GS) using traditional analyses and machine learning (ML). We conducted a pilot, cross-sectional feasibility study with convenience samples. We assessed GS using a hand-grip dynamometer and GTES using the ToeScale. The data analysis included descriptive statistics, correlations, independent samples t-tests, and accuracy and area under the curve (AUC) scores for three ML models. Thirty-one participants (males: 9; females: 22), 14 young (18-24 years) and 17 older (>65 years) adults, participated in the study. Males had significantly higher peak GTES than females in both age groups. The associations of GTES parameters with BMI and GS varied by age and sex. The ML model accuracies and AUC scores were low-moderate but aligned with traditional analyses. Future studies with larger samples and optimized ML models are needed.

The First Patient with Tibial Hemimelia-Polysyndactyly-Triphalangeal Thumb Syndrome Caused by De Novo c.423+4916 T>C ZRS Variant: A Case Report.

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.