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The Veterinary Clinics of North... Mar 2021Fractures and ligamentous injuries of the front paw are common in small animals and usually result from direct trauma, such as vehicular accident, collision with a... (Review)
Review
Fractures and ligamentous injuries of the front paw are common in small animals and usually result from direct trauma, such as vehicular accident, collision with a stationary object, falls from a height, or entrapment of the paw with leverage (eg, stepping in a hole while running). Metacarpal and phalangeal fractures may be associated with concurrent ligamentous injury. Tendon and paw injuries are generally associated with direct traumatic etiologies, such as laceration. Treatment of digit injuries follows the principles of surgery associated with similar injuries at other anatomic locations. External coaptation may be necessary to protect undersized implants.
Topics: Animals; Dogs; Finger Injuries; Finger Phalanges; Metacarpal Bones
PubMed: 33558010
DOI: 10.1016/j.cvsm.2020.12.001 -
Journal of Neurophysiology Oct 2019It is tempting to describe human reach-to-grasp movements in terms of two, more or less independent visuomotor channels, one relating hand transport to the object's... (Review)
Review
It is tempting to describe human reach-to-grasp movements in terms of two, more or less independent visuomotor channels, one relating hand transport to the object's location and the other relating grip aperture to the object's size. Our review of experimental work questions this framework for reasons that go beyond noting the dependence between the two channels. Both the lack of effect of size illusions on grip aperture and the finding that the variability in grip aperture does not depend on the object's size indicate that size information is not used to control grip aperture. An alternative is to describe grip formation as emerging from controlling the movements of the digits in space. Each digit's trajectory when grasping an object is remarkably similar to its trajectory when moving to tap the same position on its own. The similarity is also evident in the fast responses when the object is displaced. This review develops a new description of the speed-accuracy trade-off for multiple effectors that is applied to grasping. The most direct support for the digit-in-space framework is that prism-induced adaptation of each digit's tapping movements transfers to that digit's movements when grasping, leading to changes in grip aperture for adaptation in opposite directions for the two digits. We conclude that although grip aperture and hand transport are convenient variables to describe grasping, treating grasping as movements of the digits in space is a more suitable basis for understanding the neural control of grasping.
Topics: Fingers; Hand Strength; Humans; Illusions; Motor Skills; Movement; Size Perception
PubMed: 31339802
DOI: 10.1152/jn.00123.2019 -
Journal of Bone and Mineral Research :... Feb 2022Amputation of the mouse digit tip results in blastema-mediated regeneration. In this model, new bone regenerates de novo to lengthen the amputated stump bone, resulting...
Amputation of the mouse digit tip results in blastema-mediated regeneration. In this model, new bone regenerates de novo to lengthen the amputated stump bone, resulting in a functional replacement of the terminal phalangeal element along with associated non-skeletal tissues. Physiological examples of bone repair, such as distraction osteogenesis and fracture repair, are well known to require mechanical loading. However, the role of mechanical loading during mammalian digit tip regeneration is unknown. In this study, we demonstrate that reducing mechanical loading inhibits blastema formation by attenuating bone resorption and wound closure, resulting in the complete inhibition of digit regeneration. Mechanical unloading effects on wound healing and regeneration are completely reversible when mechanical loading is restored. Mechanical unloading after blastema formation results in a reduced rate of de novo bone formation, demonstrating mechanical load dependence of the bone regenerative response. Moreover, enhancing the wound-healing response of mechanically unloaded digits with the cyanoacrylate tissue adhesive Dermabond improves wound closure and partially rescues digit tip regeneration. Taken together, these results demonstrate that mammalian digit tip regeneration is mechanical load-dependent. Given that human fingertip regeneration shares many characteristics with the mouse digit tip, these results identify mechanical load as a previously unappreciated requirement for de novo bone regeneration in humans. © 2021 American Society for Bone and Mineral Research (ASBMR).
Topics: Amputation, Surgical; Animals; Bone Regeneration; Bone and Bones; Mice; Osteogenesis; Wound Healing
PubMed: 34783092
DOI: 10.1002/jbmr.4470 -
Disease Markers 2021Behcet syndrome (BS) is a multisystemic perivasculitis whose genetic susceptibility is linked to HLA region. We first meta-analysed all HLA class I and II genes involved... (Meta-Analysis)
Meta-Analysis Review
Behcet syndrome (BS) is a multisystemic perivasculitis whose genetic susceptibility is linked to HLA region. We first meta-analysed all HLA class I and II genes involved in BS susceptibility in all ethnic groups worldwide. We identified 1141 articles and finally included 31 case-control studies after multiple rounds of selection. We analysed frequencies for 24 HLA-A alleles (3 alleles for HLA-A∗26 at four digits), 50 HLA-B alleles (11 alleles for HLA-B∗51 at four digits), 15 HLA-C alleles, 16 HLA-DRB1 alleles, 6 HLA-DQB1 alleles, and 15 HLA-DPB1 alleles. We meta-analysed only HLA allelic frequencies from at least three studies; therefore, we investigated 21 alleles out of 140. Going from 7.00 to 1.6 OR, we found 11 class I alleles conferring risk for BS: B∗51 : 08, B∗51, B∗51 : 01, B∗51 : 02, DQB1∗03, A∗26 : 01, Cw∗14, Cw∗15, Cw∗16, B∗15, and A∗26. Overall, the studies included populations from Europe (Greece, Spain, Italy, Germany, and Ireland), Asia (Korea, China, China Han, and Thailand), Middle East (Israel, Saudi Arabia, and Iran), and Morocco (as no other North-African population was included). We collected a number of ethnical groups sufficient to conduct an ethnic-specific meta-analysis where Europeans showed 11.25 OR for B∗51:08 and Japan 3.50 OR for A∗26 : 01. A remarkable result was that the most frequent HLA - B∗51 two-digit alleles associated with BS were different among populations: HLA - B∗51 : 08 in Europe, HLA - B∗51 : 01 in Turkey, and HLA - B∗51 : 02 in Japan. Overall, we discussed our real-world results with other imputation studies.
Topics: Behcet Syndrome; Case-Control Studies; China; Genes, MHC Class I; HLA-DP beta-Chains; HLA-DQ beta-Chains; Humans; Japan; Polymorphism, Genetic; Republic of Korea
PubMed: 34938376
DOI: 10.1155/2021/9348697 -
Developmental Biology Jun 2022It is long-established that innervation-dependent production of neurotrophic factors is required for blastema formation and epimorphic regeneration of appendages in fish...
It is long-established that innervation-dependent production of neurotrophic factors is required for blastema formation and epimorphic regeneration of appendages in fish and amphibians. The regenerating mouse digit tip and the human fingertip are mammalian models for epimorphic regeneration, and limb denervation in mice inhibits this response. A complicating issue of limb denervation studies in terrestrial vertebrates is that the experimental models also cause severe paralysis therefore impairing appendage use and diminishing mechanical loading of the denervated tissues. Thus, it is unclear whether the limb denervation impairs regeneration via loss of neurotrophic signaling or loss of mechanical load, or both. Herein, we developed a novel surgical procedure in which individual digits were specifically denervated without impairing ambulation and mechanical loading. We demonstrate that digit specific denervation does not inhibit but attenuates digit tip regeneration, in part due to a delay in wound healing. However, treating denervated digits with a wound dressing that enhances closure results in a partial rescue of the regeneration response. Contrary to the current understanding of mammalian epimorphic regeneration, these studies demonstrate that mouse digit tip regeneration is not peripheral nerve dependent, an observation that should inform continued mammalian regenerative medicine approaches.
Topics: Amputation, Surgical; Animals; Denervation; Extremities; Mammals; Mice; Wound Healing
PubMed: 35353991
DOI: 10.1016/j.ydbio.2022.03.007 -
The South African Journal of Psychiatry... 2021Schizophrenia is a debilitating mental health condition affecting the lives of many South Africans. The origins of the heterogeneity in the presentation of the illness...
BACKGROUND
Schizophrenia is a debilitating mental health condition affecting the lives of many South Africans. The origins of the heterogeneity in the presentation of the illness remain uncertain.
AIM
This cross-sectional study performed a retrospective data analysis to determine the usefulness of digit ratio as an endophenotype in a South African schizophrenia population.
SETTING
A large genetic study in a South African schizophrenia population recruited patients from services in the Western and Eastern Cape.
METHODS
Complete clinical histories were captured for participants, including sets of images of the face and extremities. Software was utilised to measure the lengths of participants' digits from said images and digit ratios (2D:4D) were calculated. Descriptive analyses were performed on the ratios and statistical differences in digit ratio means were calculated between groups characterised by sex, age of onset and the presence vs absence of positive symptoms. Linear modelling was utilised to assess for correlates between 2D:4D and positive and negative symptom severity using scores obtained from the Positive and Negative Syndrome Scale (PANSS) and Scale for the Assessment of Negative Symptoms (SANS).
RESULTS
2D:4D in male participants did not significantly differ from female participants as in healthy populations. 2D:4D did not significantly correlate with the severity of positive or negative symptoms and 2D:4D means between groups did not significantly relate to age of onset.
CONCLUSION
2D:4D appears to be a possible endophenotype in schizophrenia in this population. 2D:4D, however, may not be as readily identifiable as certain minor physical anomalies and neurological soft signs significantly associated with schizophrenia in this population.
PubMed: 33824756
DOI: 10.4102/sajpsychiatry.v27i0.1587 -
Human Brain Mapping Jun 2023Scientists traditionally use passive stimulation to examine the organisation of primary somatosensory cortex (SI). However, given the close, bidirectional relationship...
Scientists traditionally use passive stimulation to examine the organisation of primary somatosensory cortex (SI). However, given the close, bidirectional relationship between the somatosensory and motor systems, active paradigms involving free movement may uncover alternative SI representational motifs. Here, we used 7 Tesla functional magnetic resonance imaging to compare hallmark features of SI digit representation between active and passive tasks which were unmatched on task or stimulus properties. The spatial location of digit maps, somatotopic organisation, and inter-digit representational structure were largely consistent between tasks, indicating representational consistency. We also observed some task differences. The active task produced higher univariate activity and multivariate representational information content (inter-digit distances). The passive task showed a trend towards greater selectivity for digits versus their neighbours. Our findings highlight that, while the gross features of SI functional organisation are task invariant, it is important to also consider motor contributions to digit representation.
Topics: Humans; Somatosensory Cortex; Brain Mapping; Fingers; Magnetic Resonance Imaging; Movement
PubMed: 37145934
DOI: 10.1002/hbm.26298 -
JAMA Network Open Oct 2021Risk-adjusted variation in surgeon outcomes has been traditionally explained by surgeon volume and hospital infrastructure, yet it is unclear how a surgeon's operative...
IMPORTANCE
Risk-adjusted variation in surgeon outcomes has been traditionally explained by surgeon volume and hospital infrastructure, yet it is unclear how a surgeon's operative proficiency directly contributes to their patients' outcomes.
OBJECTIVE
To assess the variation of surgeons' operative proficiency and investigate its association with surgical outcomes.
DESIGN, SETTING, AND PARTICIPANTS
This case series was a retrospective analysis of all digit replantations and revascularizations at a single US university medical center between January 2000 and August 2020. Surgeons were assigned a proficiency score based on the expected procedure difficulty and outcomes from a sample of their cases. Surgeon proficiency scores were then used to determine associations with outcomes from subsequent cases. The expected difficulty of each case was calculated using a novel scoring system that applied pooled relative risks from a meta-analysis of risk factors for replantation and revascularization failure.
EXPOSURES
Digit replantation and revascularization.
MAIN OUTCOMES AND MEASURES
Digit survival at 1-month follow up (case success) and number of complications.
RESULTS
A total of 145 patients and 226 digits were treated by 11 surgeons with training in hand or microsurgery (mean [SD] age, 41.9 [15.2] years; 204 [90%] men); there were 116 replantations and 110 revascularizations. Surgeon proficiency scores ranged from 1.3 to 5.7, with a mean (SD) of 3.4 (1.4). Case success rates among surgeons varied from 20.0% to 90.5%, with a mean (SD) of 64.9%. Higher proficiency scores were associated with fewer case failures: each point increase was associated with 40% decreased odds of failure (odds ratio, 0.60; 95% CI, 0.38-0.94). Every 3-point increase in proficiency score was associated with 1 less complication (effect estimate, -0.29; 95% CI, -0.56 to 0.02). Surgeon proficiency score had a greater association with case failure than surgeon volume (16.7% vs 12.0%). The final model's association with case failure had an area under the receiver operating characteristics curve of 0.93.
CONCLUSIONS AND RELEVANCE
Operative proficiency varied widely among practicing surgeons and accounted for 17% of estimative ability for success of digit replantation and revascularization. Greater surgeon proficiency was associated with better outcomes, indicating that the value of surgical care may be optimized by improving surgeon proficiency.
Topics: Adult; Amputation, Surgical; Clinical Competence; Female; Fingers; Humans; Logistic Models; Male; Middle Aged; Odds Ratio; Propensity Score; Replantation; Retrospective Studies; Surgeons; Treatment Outcome
PubMed: 34698849
DOI: 10.1001/jamanetworkopen.2021.28765 -
Cognition Jan 2023Number line estimation tasks are frequently used to study numerical cognition skills. In a typical version, the bounded number line task, target numerals must be placed...
Number line estimation tasks are frequently used to study numerical cognition skills. In a typical version, the bounded number line task, target numerals must be placed on a bounded line labeled only at its endpoints (e.g., with 0 and 100). Placements by adults, while highly accurate, reveal a cyclical pattern of over- and underestimation of target numerals. The pattern suggests use of proportion judgment strategies and is well-captured by cyclical power models. Another systematic number line bias that has recently been observed, but has not yet been considered in modeling efforts, is the left digit effect. Numerals with different leftmost digits (e.g., 39 and 41) are placed farther apart on a line than is warranted. In the current study (N = 60), adult estimates were obtained for all numerals on a 0-100 number line estimation task, and fit of the standard cyclical power model was compared with two modified versions of the model. One modified version included a parameter that underweights the rightward digit's place value (e.g., the ones digit here), and the other used the same parameter to underweight all digits' place values. We found that both modifications provided a considerably better fit for individual and median data than the standard model, and we discuss their relative merits and cognitive interpretations. The data and models suggest how a left digit bias might impact estimates across the number line.
Topics: Adult; Humans; Mathematics; Judgment; Cognition
PubMed: 36228381
DOI: 10.1016/j.cognition.2022.105257 -
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