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Cureus Dec 2021Background Digital replantation is associated with a substantial risk of failure. There is considerable variation in survival rates globally, and the current data are...
Background Digital replantation is associated with a substantial risk of failure. There is considerable variation in survival rates globally, and the current data are limited by poor statistical methods and bias of selection, which limits its translation to Europe and the USA. We aimed to establish a more representative survival rate of digit replantation for western populations and evaluate espoused prognostic variables using robust statistical methodology. Materials and Methods Retrospective data were collected from 58 consecutive patients who underwent digital replantation following traumatic amputation in three tertiary care hand centres in the UK over seven years. The unit of analysis was the digit. Generalized linear modelling was used to estimate the odds ratio (OR) of digit survival. Results Forty-six of 68 replanted digits survived (68%). The typical replant candidate was a 40-year-old male manual worker. Digit survival was more likely with guillotine injuries (adjusted OR 25.5 [95% CI 5.60, 115]) and when intraoperative skeletal shortening was performed (adjusted OR 15.3 [95% CI 2.62, 89.5]). The age of the patient, seniority of the operating surgeon, and use of vein grafts was not associated with digit survival. Conclusion We provide robust data to show that guillotine amputations have more favourable survival rates, which can be further improved by skeletal shortening at the time of replantation. We suggest that research networks worldwide set up digit amputation registries to capture individual patient data on this uncommon injury.
PubMed: 34909346
DOI: 10.7759/cureus.20183 -
Anatomical Record (Hoboken, N.J. : 2007) Jun 2007Cetaceans (whales, dolphins, and porpoises) have a soft tissue flipper that encases most of the forelimb, and elongated digits with an increased number of phalanges...
Cetaceans (whales, dolphins, and porpoises) have a soft tissue flipper that encases most of the forelimb, and elongated digits with an increased number of phalanges (hyperphalangy). In addition, some cetaceans exhibit a reduction in digit number. Although toothed cetaceans (odontocetes) are pentadactylous, most baleen whales (mysticetes) are tetradactylous and also lack a metacarpal. This study conducts a survey of cetacean metacarpal and phalangeal morphologies, traces the evolution of hyperphalangy in a phylogenetic context, optimizes characters onto previously published cetacean phylogenies, and tests various digit loss hypotheses. Dissections were performed on 16 cetacean flippers representing 10 species (8 mysticetes, 2 odontocetes). Phalangeal count data were derived from forelimb radiographs (36 odontocetes, 5 mysticetes), osteological specimens of articulated forelimbs (8 mysticetes), and were supplemented with published counts. Modal phalangeal counts were coded as ordered and unpolarized characters and optimized onto two known cetacean phylogenies. Results indicate that digital ray I is reduced in many cetaceans (except Globicephala) and all elements of digital ray I were lost in tetradactylous mysticetes. Fossil evidence indicates this ray may have been lost approximately 14 Ma. Most odontocetes also reduce the number of phalangeal elements in digit V, while mysticetes typically retain the plesiomorphic condition of three phalanges. Results from modal phalangeal counts show the greatest degree of hyperphalangy in digits II and III in odontocetes and digits III and IV in mysticetes. Fossil evidence indicates cetacean hyperphalangy evolved by at least 7-8 Ma. Digit loss and digit positioning may underlie disparate flipper shapes, with narrow, elongate flippers facilitating fast swimming and broad flippers aiding slow turns. Hyperphalangy may help distribute leading edge forces, and multiple interphalangeal joints may smooth leading edge flipper contour.
Topics: Adaptation, Physiological; Animals; Animals, Newborn; Biological Evolution; Cetacea; Forelimb; Morphogenesis; Phylogeny
PubMed: 17516431
DOI: 10.1002/ar.20532 -
Frontiers in Genetics 2015An open problem in biology is to derive general principles that capture how morphogenesis evolved to generate diverse forms in different organisms. Here we discuss... (Review)
Review
An open problem in biology is to derive general principles that capture how morphogenesis evolved to generate diverse forms in different organisms. Here we discuss recent work investigating the morphogenetic basis for digit loss in vertebrate limbs and variation in form of marginal outgrowths of angiosperm (flowering plant) leaves. Two pathways underlie digit loss in vertebrate limbs. First, alterations to digit patterning arise through modification of expression of the Patched 1 receptor, which senses the Sonic Hedgehog morphogen and limits its mobility in the limb bud. Second, evolutionary changes to the degree of programmed cell death between digits influence their development after their initiation. Similarly, evolutionary modification of leaf margin outgrowths occurs via two broad pathways. First, species-specific transcription factor expression modulates outgrowth patterning dependent on regulated transport of the hormone auxin. Second, species-specific expression of the newly discovered REDUCED COMPLEXITY homeodomain transcription factor influences growth between individual outgrowths after their initiation. These findings demonstrate that in both plants and animals tinkering with either patterning or post-patterning processes can cause morphological change. They also highlight the considerable flexibility of morphological evolution and indicate that it may be possible to derive broad principles that capture how morphogenesis evolved across complex eukaryotes.
PubMed: 26442102
DOI: 10.3389/fgene.2015.00284 -
Dermatology Practical & Conceptual Jan 2019The term melanonychia describes a black-brown-gray pigmentation of the nail plate that, in most cases, appears as a longitudinal band. Melanonychia can be observed at...
The term melanonychia describes a black-brown-gray pigmentation of the nail plate that, in most cases, appears as a longitudinal band. Melanonychia can be observed at any age, affecting one digit or several digits, in both fingernails and toenails. Its causes can be difficult to differentiate clinically and depend on the number of bands and on their color, edge, and width. For this reason, especially in adults and when the pigmentation is localized in one single digit, biopsy and histopathological examination still represent the gold standard for a definitive diagnosis. Dermoscopy should be used routinely in the evaluation of a pigmented nail, as it provides important information for the management of melanonychia and can help avoid unnecessary nail biopsies. In cases of melanonychia it is important to establish whether the pigment is melanin or not and to determine whether the pigmentation of melanin is due to activation or proliferation and whether it is benign or malignant.
PubMed: 30775147
DOI: 10.5826/dpc.0901a10 -
Journal of Medical Genetics Jun 1980The dermatoglyphs of 13 Japanese (eight males and five females) with duplication of the thumb were studied. The dermal patterns on the thumb were compared with those on...
The dermatoglyphs of 13 Japanese (eight males and five females) with duplication of the thumb were studied. The dermal patterns on the thumb were compared with those on the extra digit. A whorl on the thumb was associated with a whorl on the extra digit in two cases, a radial loop in four cases, and an arch in two cases. Where the thumb pattern was a loop the pattern on the extra digit was a loop in all three cases. Where the thumb and extra digit are both well developed the pattern tends to be the same on both digits. When the extra digit is poorly developed it tends to have a different pattern from the thumb.
Topics: Child, Preschool; Dermatoglyphics; Female; Humans; Infant; Male; Thumb
PubMed: 7401131
DOI: 10.1136/jmg.17.3.194 -
Proceedings. Biological Sciences Aug 2017Digit reduction is a major trend that characterizes horse evolution, but its causes and consequences have rarely been quantitatively tested. Using beam analysis on...
Digit reduction is a major trend that characterizes horse evolution, but its causes and consequences have rarely been quantitatively tested. Using beam analysis on fossilized centre metapodials, we tested how locomotor bone stresses changed with digit reduction and increasing body size across the horse lineage. Internal bone geometry was captured from 13 fossil horse genera that covered the breadth of the equid phylogeny and the spectrum of digit reduction and body sizes, from to To account for the load-bearing role of side digits, a novel, continuous measure of digit reduction was also established-toe reduction index (TRI). Our results show that without accounting for side digits, three-toed horses as late as would have experienced physiologically untenable bone stresses. Conversely, when side digits are modelled as load-bearing, species at the base of the horse radiation through probably maintained a similar safety factor to fracture stress. We conclude that the centre metapodial compensated for evolutionary digit reduction and body mass increases by becoming more resistant to bending through substantial positive allometry in internal geometry. These results lend support to two historical hypotheses: that increasing body mass selected for a single, robust metapodial rather than several smaller ones; and that, as horse limbs became elongated, the cost of inertia from the side toes outweighed their utility for stabilization or load-bearing.
Topics: Animals; Biological Evolution; Body Size; Equidae; Extremities; Fossils; Phylogeny; Weight-Bearing
PubMed: 28835559
DOI: 10.1098/rspb.2017.1174 -
Anatomical Record (Hoboken, N.J. : 2007) Dec 2008The Homeobox (Hox) genes direct the development of tetrapod digits. The expression of Hox genes may be influenced by endogenous sex steroids during development. Manning...
The Homeobox (Hox) genes direct the development of tetrapod digits. The expression of Hox genes may be influenced by endogenous sex steroids during development. Manning (Digit ratio. New Brunswick, NJ: Rutgers University Press, 2002) predicted that the ratio between the lengths of digits 2 (2D) and 4 (4D) should be sexually dimorphic because prenatal exposure to estrogens and androgens positively influence the lengths of 2D and 4D, respectively. We measured digits and other morphological traits of birds from three orders (Passeriformes, house sparrow, Passer domesticus; tree swallow, Tachycineta bicolor; Pscittaciformes, budgerigar, Melopsittacus undulates; Galliformes, chicken, Gallus domesticus) to test this prediction. None were sexually dimorphic for 2D:4D and there were no associations between 2D:4D and other sexually dimorphic traits. When we pooled data from all four species after we averaged right and left side digits from each individual and z-transformed the resulting digit ratios, we found that males had significantly larger 2D:4D than did females. Tetrapods appear to be sexually dimorphic for 2D:4D with 2D:4D larger in males as in some birds and reptiles and 2D:4D smaller in males as in some mammals. The differences between the reptile and mammal lineages in the directionality of 2D:4D may be related to the differences between them in chromosomal sex determination. We suggest that (a) natural selection for a perching foot in the first birds may have overridden the effects of hormones on the development of digit ratio in this group of vertebrates and (b) caution be used in making inferences about prenatal exposure to hormones and digit ratio in birds.
Topics: Animals; Biological Evolution; Birds; Body Patterning; Chickens; Female; Functional Laterality; Gonadal Steroid Hormones; Male; Mammals; Organogenesis; Parakeets; Reptiles; Sex Characteristics; Sparrows; Species Specificity; Swallows; Toes; Wings, Animal
PubMed: 18833568
DOI: 10.1002/ar.20769 -
Experimental Brain Research Jul 2007When grasping rectangular or circular objects with a precision grip the digits close in on the object in opposite directions. In doing so the digits move perpendicular...
When grasping rectangular or circular objects with a precision grip the digits close in on the object in opposite directions. In doing so the digits move perpendicular to the local surface orientation as they approach opposite sides of the object. This perpendicular approach is advantageous for accurately placing the digits. Trapezoidal objects have non-parallel surfaces so that moving the digits in opposite directions would make the digits approach the contact surfaces at an angle that is not 90 degrees . In this study we examined whether this happens, or whether subjects tend to approach trapezoidal objects' surfaces perpendicularly. We used objects of different sizes and with different surface slants. Subjects tended to approach the object's surfaces orthogonally, suggesting that they aim for an optimal precision of digit placement rather than simply closing their hand as it reaches the object.
Topics: Adult; Female; Fingers; Hand; Hand Strength; Humans; Male; Movement; Neuropsychological Tests; Orientation; Psychomotor Performance; Reaction Time; Space Perception; Visual Perception
PubMed: 17310376
DOI: 10.1007/s00221-007-0867-6 -
JAMA Network Open Aug 2022Terminal digit preference has been shown to be associated with inaccurate blood pressure (BP) recording.
IMPORTANCE
Terminal digit preference has been shown to be associated with inaccurate blood pressure (BP) recording.
OBJECTIVE
To evaluate whether converting from manual BP measurement with aneroid sphygmomanometers to automated BP measurement was associated with terminal digit preference, mean levels of recorded BP, and the rate at which hypertension was diagnosed.
DESIGN, SETTING, AND PARTICIPANTS
This quality improvement study was conducted from May 9, 2021, to March 24, 2022, using interrupted time series analysis of medical record data from 11 primary care clinics in a single health care system from April 2008 to April 2015. The study population was patients aged 18 to 75 years who had their BP measured and recorded at least once during the study period.
EXPOSURES
Manual BP measurement before April 2012 vs automated BP measurement with the Omron HEM-907XL monitor from May 2012 to April 2015.
MAIN OUTCOMES AND MEASURES
The main outcome was the distribution of terminal digits and mean systolic BP (SBP) values obtained during 4 years of manual measurement vs 3 years of automated measurement, assessed using a generalized linear mixed regression model with a random intercept for clinic and adjusted for seasonal fluctuations and patient demographic and clinical characteristics.
RESULTS
The study included 1 541 227 BP measurements from 225 504 unique patients during the entire study period, with 849 978 BP measurements from 165 137 patients (mean [SD] age, 47.1 [15.2] years; 58.2% female) during the manual measurement period and 691 249 measurements from 149 080 patients (mean [SD] age, 48.4 [15.3] years; 56.3% female) during the automated measurement period. With manual measurement, 32.8% of SBP terminal digits were 0 (20% was the expected value because nursing staff was instructed to record BP to the nearest even digit). This proportion decreased to 12.4% during the automated measurement period (expected value, 10%) when both even and odd digits were to be recorded. After automated measurement was implemented, the mean SBP estimated with statistical modeling increased by 5.09 mm Hg (95% CI, 4.98-5.19 mm Hg). Fewer BP values recorded during the automated than the manual measurement period were below 140/90 mm Hg (69.9% vs 84.3%; difference, -14.5%; 95% CI, -14.6% to -14.3%) and below 130/80 mm Hg (42.1% vs 60.0%; difference, -17.9%; 95% CI, -18.0% to -17.7%). The proportion of patients with a diagnosis of hypertension was 4.3 percentage points higher (23.4% vs 19.1%) during the automated measurement period.
CONCLUSIONS AND RELEVANCE
In this quality improvement study, automated BP measurement was associated with decreased terminal digit preference and significantly higher mean BP levels. The method of BP measurement was also associated with the rate at which hypertension was diagnosed. These findings may have implications for pay-for-performance programs, which may create an incentive to record BP levels that meet a particular goal and a disincentive to adopt automated measurement of BP.
Topics: Blood Pressure; Blood Pressure Determination; Female; Humans; Hypertension; Male; Middle Aged; Quality Improvement; Reimbursement, Incentive
PubMed: 36044216
DOI: 10.1001/jamanetworkopen.2022.29098 -
Journal of Hand Surgery Global Online Jul 2022A closed mallet injury is a common finger injury involving terminal extensor tendon avulsion from its insertion on the distal phalanx. Nonsurgical treatment with...
PURPOSE
A closed mallet injury is a common finger injury involving terminal extensor tendon avulsion from its insertion on the distal phalanx. Nonsurgical treatment with continuous extension orthosis fabrication is the preferred treatment. Our purpose was to report the failure rates of orthotic management by digit and investigate other factors that contribute to failure.
METHODS
This was a retrospective chart review of all patients with an isolated mallet finger injury managed at our institution from 2011 to 2019. Patient demographics, details of management, and treatment outcomes were collected. Failure rates were compared for all digits, specifically comparing the little finger versus all other digits. A categorical variable analysis was performed to identify risk factors for failure of orthosis management.
RESULTS
Out of 1,331 identified patients, 328 met the inclusion criteria. There was no statistically significant difference of failure rate between digits. There was a trend toward the little finger failing at a higher rate (n = 131, 40%) than the other digits individually ( = .08) and combined (n = 95, 29%; = .06). An older age at injury was associated with failure. The median patient age with failure was 54 years, versus the median patient age with nonfailure of 48 years ( < .01). The failure rate was higher in tendinous versus bony mallet injuries (n = 131, 40% vs n = 66, 20%, respectively; < .01). The orthotic type was associated with the failure rate, and failure was highest in patients treated with Stack orthoses (n = 183, 56%; = .01).
CONCLUSIONS
There was no significant difference in the orthotic management failure rate by digit for a mallet injury. Statistically significant risk factors for failure are increasing age, a tendinous injury, and the orthotic type. Further evaluation with a larger cohort is warranted to increase the statistical power of the findings.
TYPE OF STUDY/LEVEL OF EVIDENCE
Therapeutic III.
PubMed: 35880156
DOI: 10.1016/j.jhsg.2022.04.003