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Regeneration (Oxford, England) Aug 2015A variety of digit and limb repair and reconstruction methods have been used in different clinical settings, but regeneration remains an item on every plastic surgeon's... (Review)
Review
A variety of digit and limb repair and reconstruction methods have been used in different clinical settings, but regeneration remains an item on every plastic surgeon's "wish list." Although surgical salvage techniques are continually being improved, unreplantable digits and limbs are still abundant. We comprehensively review the structural and functional salvage methods in clinical practice, from the peeling injuries of small distal fingertips to multisegmented amputated limbs, and the developmental and tissue engineering approaches for regenerating human digits and limbs in the laboratory. Although surgical techniques have forged ahead, there are still situations in which digits and limbs are unreplantable. Advances in the field are delineated, and the regeneration processes of salamander limbs, lizard tails, and mouse digits and each component of tissue engineering approaches for digit- and limb-building are discussed. Although the current technology is promising, there are many challenges in human digit and limb regeneration. We hope this review inspires research on the critical gap between clinical and basic science, and leads to more sophisticated digit and limb loss rescue and regeneration innovations.
PubMed: 27499873
DOI: 10.1002/reg2.41 -
The International Journal of... 2018The distal part of the tetrapod limb, the autopod, is characterized by the presence of digits. The digits display a wide diversity of shapes and number reflecting... (Review)
Review
The distal part of the tetrapod limb, the autopod, is characterized by the presence of digits. The digits display a wide diversity of shapes and number reflecting selection pressure for functional adaptation. Despite extensive study, the different aspects of digit patterning, as well as the factors and mechanisms involved are not completely understood. Here, we review the evidence implicating Hox proteins in digit patterning and the interaction between Hox genes and the Sonic hedgehog/Gli3 pathway, the other major regulator of digit number and identity. Currently, it is well accepted that a self-organizing Turing-type mechanism underlies digit patterning, this being understood as the establishment of an iterative arrangement of digit/interdigit in the hand plate. We also discuss the involvement of 5' Hox genes in regulating digit spacing in the digital plate and therefore the number of digits formed in this self-organizing system.
Topics: Animals; Body Patterning; Extremities; Gene Expression Regulation, Developmental; Genes, Homeobox; Hedgehog Proteins; Signal Transduction
PubMed: 30604849
DOI: 10.1387/ijdb.180200mr -
International Journal of Cell Biology 2017Tissue regeneration and repair have received much attention in the medical field over the years. The study of amphibians, such as newts and salamanders, has uncovered... (Review)
Review
Tissue regeneration and repair have received much attention in the medical field over the years. The study of amphibians, such as newts and salamanders, has uncovered many of the processes that occur in these animals during full-limb/digit regeneration, a process that is highly limited in mammals. Understanding these processes in amphibians could shed light on how to develop and improve this process in mammals. Amputation injuries in mammals usually result in the formation of scar tissue with limited regrowth of the limb/digit; however, it has been observed that the very tips of digits (fingers and toes) can partially regrow in humans and mice under certain conditions. This review will summarize and compare the processes involved in salamander limb regeneration, mammalian wound healing, and digit regeneration in mice and humans.
PubMed: 28487741
DOI: 10.1155/2017/5312951 -
Journal of Exercise Rehabilitation Dec 2016Second to fourth digit ratio is the ratio of second to fourth digit length. It has been known that digit ratio is sexually dimorphic in humans, such that males tend to... (Review)
Review
Second to fourth digit ratio is the ratio of second to fourth digit length. It has been known that digit ratio is sexually dimorphic in humans, such that males tend to have lower digit ratio (longer fourth digits relative to second digits) than females. Digit ratio is thought to be a biomarker of the balance between fetal testosterone (FT) and fetal estrogen (FE) in a relatively narrow developmental window at the end of the first trimester of pregnancy. On the contrary, the relationships between digit ratio and levels of sex steroids in adults are not clear. Most correlational studies between digit ratio and adult sex steroids have revealed that this association is statistically not significant. However, for many years, a lot of researches showed negative relationships between digit ratio and sports performance such as rugby, surfing, rowing, sprinting, endurance, and hand grip strength. Here, we discuss possible mechanisms about the relationships between digit ratio and sports performance.
PubMed: 28119871
DOI: 10.12965/jer.1632862.431 -
Development (Cambridge, England) Sep 2020The vertebrate limb continues to serve as an influential model of growth, morphogenesis and pattern formation. With this Review, we aim to give an up-to-date picture of... (Review)
Review
The vertebrate limb continues to serve as an influential model of growth, morphogenesis and pattern formation. With this Review, we aim to give an up-to-date picture of how a population of undifferentiated cells develops into the complex pattern of the limb. Focussing largely on mouse and chick studies, we concentrate on the positioning of the limbs, the formation of the limb bud, the establishment of the principal limb axes, the specification of pattern, the integration of pattern formation with growth and the determination of digit number. We also discuss the important, but little understood, topic of how gene expression is interpreted into morphology.
Topics: Animals; Body Patterning; Extremities; Gene Expression Regulation, Developmental; Limb Buds; Vertebrates
PubMed: 32917670
DOI: 10.1242/dev.177956 -
Cureus Aug 2020A 36-year-old man presented with incidental findings of an asymmetric chest with hypoplastic and flattened left anterior chest wall due to absent left pectoralis major....
A 36-year-old man presented with incidental findings of an asymmetric chest with hypoplastic and flattened left anterior chest wall due to absent left pectoralis major. He also had short and webbed fingers in the left hand. These deformities were present since birth. Chest X-ray showed hyperlucency on the left side. Computerized tomography (CT) scan showed an absence of the left pectoralis major. X-ray of the left hand showed hypoplasia of the proximal phalanx and aplasia of the middle and distal phalanges of the second digit, and aplasia of the middle phalanges of the third and fourth digits. A diagnosis of left-sided Poland syndrome with associated ipsilateral brachysyndactyly, which is a very rare entity, was made. The patient opted against any reconstructive procedure as he had a minimal functional limitation.
PubMed: 32944470
DOI: 10.7759/cureus.9755 -
JPRAS Open Mar 2022Macrodactyly is a rare congenital disorder of overgrowth affecting the digits of the upper or lower extremity. Mostly, patients are surgically treated during childhood...
BACKGROUND
Macrodactyly is a rare congenital disorder of overgrowth affecting the digits of the upper or lower extremity. Mostly, patients are surgically treated during childhood to reduce the digit or to stop growth. There are no standardized guidelines for the treatment and follow-up of macrodactyly. Consequently, follow-up may not be regularly scheduled into adulthood.
METHODS
A retrospective, descriptive analysis of patients with the long-term progression of macrodactyly who presented at our tertiary referral hospital between July 2018 and March 2020 was performed. All patients from our local macrodactyly database were screened for progression of macrodactyly since adulthood; this resulted in four patients. The aim of these case series is to highlight the clinical features and disease course at long-term follow-up.
RESULTS
All patients were surgically treated during childhood and showed progression of tissue overgrowth during adult life. All patients developed severe secondary degenerative bone changes in macrodactyly affected digits, such as ankyloses of joints, new bone formation, and bony spurs. Subsequently, tissue overgrowth and degenerative bone changes led to functional problems.
CONCLUSION
Patients with macrodactyly may experience growth during adult life, which may progress to deforming changes. Consequently, patients should be informed about the possible growth, and the progressive growth should be monitored.
PubMed: 34869816
DOI: 10.1016/j.jpra.2021.10.004 -
Hand (New York, N.Y.) Jan 2021Digit replantation affords the opportunity to restore hand function following amputation. To date, however, few studies have evaluated functional outcomes following... (Meta-Analysis)
Meta-Analysis Review
Digit replantation affords the opportunity to restore hand function following amputation. To date, however, few studies have evaluated functional outcomes following replantation. Therefore, it was the objective of this study to perform a meta-analysis to better characterize the predictors of hand function. A literature search was performed using the PubMed database to identify studies that focused on digit amputation/replantation and functional outcomes. Studies were evaluated for patient- and injury-related factors and their respective effects on clinical outcomes of sensation, grip strength, and Disabilities of the Arm, Shoulder, and Hand (DASH) scores. Statistical analysis was conducted across the pooled data set to identify significant trends. Twenty-eight studies representing 618 replanted digits were included in this study. We found the average grip strength was 78.7% (relative to contralateral), the average 2-point discrimination (2PD) was 7.8 mm, and the average DASH score was 12.81. After conducting statistical analysis, we found patients with more proximal injuries had lower grip strength scores ( < .05). We found 2PD scores were influenced by age, mechanism of injury, and amputation level ( < .05). Finally, we found DASH scores after replantation were predicted by mechanism of injury and level of amputation ( < .05). The following variables did not influence outcomes: gender, tobacco use, ischemia time, and digit number. Digit replant does not restore premorbid hand function but does result in adequate hand function. Expected functional outcomes following replant should be considered in the decision-making process. These data can help risk-stratify patients, guide postreplant expectations, and influence the decision for replantation.
Topics: Amputation, Surgical; Amputation, Traumatic; Finger Injuries; Humans; Replantation; Retrospective Studies
PubMed: 30938181
DOI: 10.1177/1558944719834658