Exploring Age-Related Variations in Carpal Bone Volume: Implications for Clinical Practice and Anatomical Understanding.

BACKGROUND: Clinically recognizing the changes in carpal bone volumes and understanding their implications in predicting osteoarthritis (OA) is crucial in clinical practice This study aimed to explore age-related differences in carpal bone volumes across genders, leveraging computed tomography (CT) wrist scans to create 3D surface models of these bones. METHODS: Carpal bone volumes were calculated using the 3D Slicer software from CT scans obtained from Frankston Hospital and additional datasets from Brown and Auckland Universities. The data were statistically processed using Stata V13. Double-sided P-values < .05 were considered statistically significant. The study was conducted in accordance with the ethical standards laid out in the Declaration of Helsinki. RESULTS: A total of 181 patients were analyzed, and 48% of whom were female. A statistically significant positive Spearman correlation (rho = 0.37-0.611, P <.05) was observed between increasing age and the volume of all surveyed carpal bones (scaphoid, lunate, triquetrum, pisiform, hamate, capitate, and trapezium) across genders. Intrauser and interuser reliabilities for 3D Slicer-generated volumes of trapezium and pisiform bones were statistically significant, with Interclass Correlation Coefficient (ICC) values of 0.86 and 0.95, respectively. CONCLUSION: Trapezial volumes increase with age, potentially due to the presence of OA and consequent osteophyte formation. This pattern is more prevalent among older individuals and women. However, the positive correlation between carpal bone volume and age was consistent across all carpal bones and both genders, regardless of OA presence. These findings suggest that carpal bone volume may naturally increase with age, independent of OA-related changes. LEVEL OF EVIDENCE: III, cohort study.

The Preservation of Umbilical Blood Supply in Combined Ventral Hernia Repair and Abdominoplasty: A Narrative Review.

INTRODUCTION: Combined ventral hernia repair and abdominoplasty treat risk factors such as high body mass index and weak abdominal musculature, providing excellent intraoperative exposure and improved patient outcomes. Unfortunately, a combination of traditional procedures is unfeasible as the umbilical blood supply would be compromised, leading to increased umbilical necrosis risk. This narrative review aimed to identify new techniques and solidify evidence in preserving umbilical blood supply and associated level of evidence. METHODS: Two authors conducted a thorough literature search on PubMed, Scopus and Cochrane CENTRAL databases from January 1901 to July 2023, adhering to the methodologies of the preferred reporting items for systematic reviews and meta-analyses. Studies were reviewed for their surgical technique and quality of evidence. The primary outcomes of interest consisted of umbilical complications of this combined procedure. RESULTS: Six techniques were identified that included laparoscopic, pre-rectus, unilateral, distal bilateral, proximal bilateral, and inferior midline approaches. All techniques demonstrated as viable options in preserving umbilical blood supply as reported complications were few, minor, and compounded by risk factors. However, all included techniques were limited to low-to-moderate-quality evidence. CONCLUSION: Despite the lack of high-quality evidence, all techniques remain viable options for combined ventral hernia repair and abdominoplasty. Large-scale high-quality RCTs are required to compare the effectiveness of various approaches with additional outcomes of hernia recurrence rates, intraoperative time, and patient- and surgeon-reported satisfaction. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The impact of COVID-19 on emergency cholecystectomy.

BACKGROUNDS: The impact of the SARS-CoV-2 virus (COVID-19) upon the delivery of surgical services in Australia has not been well characterized, other than restrictions to elective surgery due to government directive-related cancellations. Using emergency cholecystectomy as a representative operation, this study aimed to investigate the impact of COVID-19 on emergency general surgery in Australia in relation to in-hours versus after-hours operating. METHODS: A retrospective analysis was conducted of medical records for patients admitted with cholecystitis or biliary colic between 1 March 2019 and 28 February 2021 at Frankston Hospital, Australia. Patient demographics, admission data, imaging findings, operative and post-operative data were compared between pre-COVID-19 and COVID-19 periods. Variables were compared using the Wilcoxon-Mann-Whitney, Chi Squared or Fishers exact test. RESULTS: During the COVID-19 period, emergency cholecystectomy was performed for a greater proportion of patients presenting with cholecystitis or biliary colic (93.5% versus 77.7%, p < 0.01). Despite this, there was concomitant reduction in after-hours cholecystectomy from 14.4% to 7.5% (p = 0.04). Patients requiring after-hours surgery during the COVID-19 period had more features of sepsis (23% more tachypnoeic, 18% more hypotensive), and were more likely to have certain features of cholecystitis on imaging (45% more likely to have pericholecystic fluid). CONCLUSION: Following elective surgery cancellations during the COVID-19 period, an increase was seen in the proportion of patients presenting with gallstone disease who were managed with emergency cholecystectomy due to improved theatre access. Concurrently, there was a decrease in the requirement for surgery to be performed after-hours.

Antithrombotic Use with Collagenase Clostridium Histolyticum Injection to Treat Dupuytren Disease.

Background: Collagenase Clostridium histolyticum (collagenase) is an injectable treatment option for Dupuytren disease. The current study was designed to investigate the safety and ensure the effectiveness of collagenase for the treatment of Dupuytren disease, with or without concomitant antithrombotic usage. Methods: One hundred and forty-eight patients with Dupuytren disease were treated with collagenase during this period; 49 taking antithrombotics and 99 not taking antithrombotics. The primary outcomes were clinical success (a reduction in joint contracture to < 5°) and clinical improvement (a reduction in joint contracture by equal to or more than 50%). Results: No statistically significant difference in either clinical success or clinical improvement was found between those taking and those not taking antithrombotics. No significant difference was found in the incidence of any adverse effects or skin splits between the two cohorts. Conclusions: Collagenase can be safely and effectively used to treat patients with Dupuytren disease who take antithrombotics.

Effects of COVID-19 lockdown measures on emergency plastic and reconstructive surgery presentations.

BACKGROUND: In Australia, the COVID-19 pandemic has caused severe social disruptions, including restrictions to the movement of people. Healthcare centres around the world have seen changes in the nature of injuries acquired during the COVID-19 pandemic; we therefore hypothesize that social isolation measures have changed the pattern of plastic and reconstructive surgery presentations. METHODS: A prospective cohort study was designed comparing patient presentations during the enforced COVID-19 lockdown to two previous periods. All emergency referrals requiring operative intervention by the plastic and reconstructive surgery unit of our institution were included. Patient demographics, place and mechanism of injury, drug and alcohol involvement, delays to presentation, length of admission and complication rates were collected. RESULTS: Demographics and complication rates were similar across all groups. A 31.8% reduction in total number of emergency cases was seen during the lockdown period. Increase in do-it-yourself injuries (P = 0.001), bicycle injuries (P = 0.001) and injuries acquired via substance abuse (P = 0.041) was observed. Head and neck injuries, mostly due to animal bites and falls, were also more prevalent compared to the same period the previous year (P = 0.007). As expected, over 80% of plastic surgery operations during the COVID-19 period were due to injuries acquired at home, a significant increase compared to previous periods. CONCLUSION: Despite changes in the pattern of presentations requiring plastic and reconstructive emergency surgery, traumatic injuries continued to occur during the pandemic. Thus, planning will be essential to ensure resource allocation for emergency procedures is sustained as second and third waves of COVID-19 cases emerge worldwide.

The influence of skin tears following collagenase treatment of Dupuytren's disease on treatment outcomes.

This study investigated influence of skin tears on patient-reported outcomes of injection of collagenase clostridium histolyticum for Dupuytren's disease and association between extension deficit of digits before injection and skin tear after the injection. From 2016 to 2018, 391 Dupuytren's cords were treated in 184 patients in a prospective cohort study and the patients were evaluated before injection and six months after injection. Skin tears occurred in 50% of these patients. We found no significant differences in the patient-reported outcomes between patients with or without skin tears. A higher extension deficit before treatment was associated with significantly increased frequency of skin tears. We conclude that the incidence of skin tears after injection does not affect patient reported outcomes six months after collagenase injection, but the incidence of skin tears is significantly associated with the severity of pre-treatment finger extension deficits.Level of evidence: II.

Dupuytren Disease Management Trends: A Survey of Hand Surgeons.

Background: Management of Dupuytren Disease is variable, and influenced by multiple factors including location, extent of disease, surgical preference and familiarity with different treatment techniques. The objective of this study was to determine current Dupuytren Disease management trends in Australia. Methods: A questionnaire was sent through The Australian Hand Surgery Society to all members. In addition to demographic data, indications and preferences for different management interventions were surveyed on location of disease, age and activity level of the patient. Results: 99 (48%) of the Australian Hand Surgery Society members completed the survey. Respondents were primarily Orthopaedic (50%) or Plastic (49%) Surgeons, and most worked in private (99%) and public (71%) practice. Surgeon's believed that Tubiana's treatment goals to correct deformity was the most important (60%) and to shorten post-operative recovery (60%) was the least important. Only 42% of respondents perform needle aponeurotomy for Dupuytren Disease. In contrast 70% of respondents perform collagenase injections, with manipulation most commonly undertaken on the second day (46%) and skin tears (52%) the most common complication. Seventy-five percent of the respondents feel there is sufficient evidence to support the treatment of Dupuytren disease with collagenase injections. Ninety nine percent of all respondents perform fasciectomes for Dupuytren Disease, with Limited (without graft) (76%) the most routine performed. Conclusions: Several procedural options for the treatment of Dupuytren Disease exist within Australia. This study shows current Australian practice trends and highlights the increasing use of collagenase.

The effectiveness of manipulation of fingers with Dupuytren's contracture 7 days after collagenase clostridial histolyticum injection.

Timing of manipulation of digits after collagenase injection for Dupuytren's disease varies and often takes place within the first few days post-injection. We prospectively investigated the effectiveness of performing manipulation under local anaesthesia 7 days after injection in 100 patients. Demographic data, passive extension deficit, and patient-reported outcome measures were recorded before collagenase injection. Four to 7 weeks after manipulation, passive extension deficit and patient-reported outcome measures improved significantly without the development of any tendon ruptures. Clinical success was achieved in 41% and clinical improvement in 76% of the patients. Adverse events were reported by 85%. The outcomes were comparable with studies with early manipulation, and demonstrate a safe and effective variation to current protocols. We conclude that delaying manipulation to 7 days after collagenase injection is safe and efficient, which allows for flexibility in clinical appointments without negatively affecting outcome. Level of evidence: III.

Failure Rates of Base of Thumb Arthritis Surgery: A Systematic Review.

PURPOSE: The purpose of the current review was to estimate failure rates of trapeziometacarpal (TMC) implants and compare against failure rates of nonimplant techniques for surgical treatment of TMC joint (basal thumb joint) arthritis. METHODS: A systematic review was conducted to identify articles reporting on thumb implant arthroplasty and on nonimplant arthroplasty techniques for treatment of base of thumb arthritis in the English literature. The collected data were combined to calculate failure rates per 100 procedure-years. Failure was defined by the requirement for a secondary salvage procedure. The failure rates between different implant and nonimplant arthroplasty groups were compared directly and implants with higher than anticipated failure rates were identified. RESULTS: One hundred twenty-five articles on implant arthroplasty and 33 articles on the outcome of nonimplant surgical arthroplasty of the TMC joint were included. The implant arthroplasty failure rates per 100 procedure-years were total joint replacement (2.4), hemiarthroplasty (2.5), interposition with partial trapezial resection (4.5), interposition with complete trapezial resection (1.7), and interposition with no trapezial resection (4.5). The nonimplant arthroplasty failure rates per 100 procedure-years were: trapeziectomy (0.49), joint fusion (0.52), and trapeziectomy with ligament reconstruction ± tendon interposition (0.23). CONCLUSIONS: Several implant designs (arthroplasties) had high rates of failure due to aseptic loosening, dislocation, and persisting pain. Furthermore, some implants had higher than anticipated failure rates than other implants within each class. Overall, the failure rates of nonimplant techniques were lower than those of implant arthroplasty. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

In-Vivo Quantitative Mapping of the Perforasomes of Deep Inferior Epigastric Artery Perforators.

BACKGROUND: There is limited understanding of anatomy of perforator angiosomes, or "perforasomes," of the deep inferior epigastric artery (DIEA). A perforasome is defined as the territory perfused by a single perforator vessel of a named artery, such as the DIEA. Given the clinical significance of this anatomical concept in microsurgical breast reconstruction, this study is a quantitative investigation of DIEA perforasome characteristics and patterns associated with perforasome size, perforator caliber, location and branching, using computed tomographic (CT) angiography. METHODS: Twenty abdominal arterial-phase CT angiograms were analyzed in 3 dimensions using software (Horos). DIEA perforasomes were mapped, yielding data on 40 medial-row and 40 lateral-row perforasomes. Perforator branch extents and number were measured using 3-dimensional multi-planar reconstruction, and perforator caliber on axial slices. RESULTS: Perforasomes exhibited eccentric branching distributions in horizontal and vertical axes, that is, a majority of perforators were not centrally located within their perforasomes. Lateral-row perforasomes displayed greater horizontal eccentricity than medial-row. There was a positive correlation between perforator caliber and perforasome size. Medial-row perforators had more branches and larger caliber than lateral-row. CONCLUSIONS: This is the first article to quantify relationships between perforators and their territories of supply in vivo, augmenting current understanding of perforasome theory. DIEA perforasomes can be readily visualized and mapped with CT angiography, which may enable effective preoperative flap planning in DIEA perforator flap breast reconstruction. Future investigation may highlight the importance of this information in improving surgical outcomes, including flap survival and fat necrosis reduction, through careful, perforasome-based flap design.

Vasopressin casts light on the suprachiasmatic nucleus.

KEY POINTS: A subpopulation of retinal ganglion cells expresses the neuropeptide vasopressin. These retinal ganglion cells project predominately to our biological clock, the suprachiasmatic nucleus (SCN). Light-induced vasopressin release enhances the responses of SCN neurons to light. It also enhances expression of genes involved in photo-entrainment of biological rhythms. ABSTRACT: In all animals, the transition between night and day engages a host of physiological and behavioural rhythms. These rhythms depend not on the rods and cones of the retina, but on retinal ganglion cells (RGCs) that detect the ambient light level in the environment. These project to the suprachiasmatic nucleus (SCN) of the hypothalamus to entrain circadian rhythms that are generated within the SCN. The neuropeptide vasopressin has an important role in this entrainment. Many SCN neurons express vasopressin, and it has been assumed that the role of vasopressin in the SCN reflects the activity of these cells. Here we show that vasopressin is also expressed in many retinal cells that project to the SCN. Light-evoked vasopressin release contributes to the responses of SCN neurons to light, and enhances expression of the immediate early gene c-fos in the SCN, which is involved in photic entrainment of circadian rhythms.

Dendritic peptide release mediates interpopulation crosstalk between neurosecretory and preautonomic networks.

Although communication between neurons is considered a function of the synapse, neurons also release neurotransmitter from their dendrites. We found that dendritic transmitter release coordinates activity across distinct neuronal populations to generate integrative homeostatic responses. We show that activity-dependent vasopressin release from hypothalamic neuroendocrine neurons in the paraventricular nucleus stimulates neighboring (~100 µm soma-to-soma) presympathetic neurons, resulting in a sympathoexcitatory population response. This interpopulation crosstalk was engaged by an NMDA-mediated increase in dendritic Ca(2+), influenced by vasopressin's ability to diffuse in the extracellular space, and involved activation of CAN channels at the target neurons. Furthermore, we demonstrate that this interpopulation crosstalk plays a pivotal role in the generation of a systemic, polymodal neurohumoral response to a hyperosmotic challenge. Because dendritic release is emerging as a widespread process, our results suggest that a similar mechanism could mediate interpopulation crosstalk in other brain systems, particularly those involved in generating complex behaviors.

The involvement of actin, calcium channels and exocytosis proteins in somato-dendritic oxytocin and vasopressin release.

Hypothalamic magnocellular neurons release vasopressin and oxytocin not only from their axon terminals into the blood, but also from their somata and dendrites into the extracellular space of the brain, and this can be regulated independently. Differential release of neurotransmitters from different compartments of a single neuron requires subtle regulatory mechanisms. Somato-dendritic, but not axon terminal release can be modulated by changes in intracellular calcium concentration [(Ca(2+))] by release of calcium from intracellular stores, resulting in priming of dendritic pools for activity-dependent release. This review focuses on our current understanding of the mechanisms of priming and the roles of actin remodeling, voltage-operated calcium channels (VOCCs) and SNARE proteins in the regulation somato-dendritic and axon terminal peptide release.

The involvement of voltage-operated calcium channels in somato-dendritic oxytocin release.

Magnocellular neurons of the supraoptic nucleus (SON) secrete oxytocin and vasopressin from axon terminals in the neurohypophysis, but they also release large amounts of peptide from their somata and dendrites, and this can be regulated both by activity-dependent Ca(2+) influx and by mobilization of intracellular Ca(2+). This somato-dendritic release can also be primed by agents that mobilise intracellular Ca(2+), meaning that the extent to which it is activity-dependent, is physiologically labile. We investigated the role of different Ca(2+) channels in somato-dendritic release; blocking N-type channels reduced depolarisation-induced oxytocin release from SONs in vitro from adult and post-natal day 8 (PND-8) rats, blocking L-type only had effect in PND-8 rats, while blocking other channel types had no significant effect. When oxytocin release was primed by prior exposure to thapsigargin, both N- and L-type channel blockers reduced release, while P/Q and R-type blockers were ineffective. Using confocal microscopy, we found immunoreactivity for Ca(v)1.2 and 1.3 channel subunits (which both form L-type channels), 2.1 (P/Q type), 2.2 (N-type) and 2.3 (R-type) in the somata and dendrites of both oxytocin and vasopressin neurons, and the intensity of the immunofluorescence signal for different subunits differed between PND-8, adult and lactating rats. Using patch-clamp electrophysiology, the N-type Ca(2+) current density increased after thapsigargin treatment, but did not alter the voltage sensitivity of the channel. These results suggest that the expression, location or availability of N-type Ca(2+) channels is altered when required for high rates of somato-dendritic peptide release.

Vasopressin and social odor processing in the olfactory bulb and anterior olfactory nucleus.

Central vasopressin facilitates social recognition and modulates numerous complex social behaviors in mammals, including parental behavior, aggression, affiliation, and pair-bonding. In rodents, social interactions are primarily mediated by the exchange of olfactory information, and there is evidence that vasopressin signaling is important in brain areas where olfactory information is processed. We recently discovered populations of vasopressin neurons in the main and accessory olfactory bulbs and anterior olfactory nucleus that are involved in the processing of social odor cues. In this review, we propose a model of how vasopressin release in these regions, potentially from the dendrites, may act to filter social odor information to facilitate odor-based social recognition. Finally, we discuss recent human research linked to vasopressin signaling and suggest that our model of priming-facilitated vasopressin signaling would be a rewarding target for further studies, as a failure of priming may underlie pathological changes in complex behaviors.

Expression of early growth response protein 1 in vasopressin neurones of the rat anterior olfactory nucleus following social odour exposure.

The anterior olfactory nucleus (AON), a component of the main olfactory system, is a cortical region that processes olfactory information and acts as a relay between the main olfactory bulbs and higher brain regions such as the piriform cortex. Utilizing a transgenic rat in which an enhanced green fluorescent protein reporter gene is expressed in vasopressin neurones (eGFP-vasopressin), we have discovered a population of vasopressin neurones in the AON. These vasopressin neurones co-express vasopressin V1 receptors. They also co-express GABA and calbinin-D28k indicating that they are neurochemically different from the newly described vasopressin neurons in the main olfactory bulb. We utilized the immediate early gene product, early growth response protein 1 (Egr-1), to examine the functional role of these vasopressin neurons in processing social and non-social odours in the AON. Exposure of adult rats to a conspecific juvenile or a heterospecific predator odour leads to increases in Egr-1 expression in the AON in a subregion specific manner. However, only exposure to a juvenile increases Egr-1 expression in AON vasopressin neurons. These data suggest that vasopressin neurones in the AON may be selectively involved in the coding of social odour information.

An intrinsic vasopressin system in the olfactory bulb is involved in social recognition.

Many peptides, when released as chemical messengers within the brain, have powerful influences on complex behaviours. Most strikingly, vasopressin and oxytocin, once thought of as circulating hormones whose actions were confined to peripheral organs, are now known to be released in the brain, where they have fundamentally important roles in social behaviours. In humans, disruptions of these peptide systems have been linked to several neurobehavioural disorders, including Prader-Willi syndrome, affective disorders and obsessive-compulsive disorder, and polymorphisms of V1a vasopressin receptor have been linked to autism. Here we report that the rat olfactory bulb contains a large population of interneurons which express vasopressin, that blocking the actions of vasopressin in the olfactory bulb impairs the social recognition abilities of rats and that vasopressin agonists and antagonists can modulate the processing of information by olfactory bulb neurons. The findings indicate that social information is processed in part by a vasopressin system intrinsic to the olfactory system.

The effects of apelin on the electrical activity of hypothalamic magnocellular vasopressin and oxytocin neurons and somatodendritic Peptide release.

Apelin, a novel peptide originally isolated from bovine stomach tissue extracts, is widely but selectively distributed throughout the nervous system. Vasopressin and oxytocin are synthesized in the magnocellular neurons of the hypothalamic supraoptic nucleus (SON) and paraventricular nucleus, which are apelin-rich regions in the central nervous system. We made extracellular electrophysiological recordings from the transpharyngeally exposed SON of urethane-anaesthetized rats to assess the role of apelin in the control of the firing activity of identified magnocellular vasopressin and oxytocin neurons in vivo. Apelin-13 administration onto SON neurons via microdialysis revealed cell-specific responses; apelin-13 increased the firing rates of vasopressin cells but had no effect on the firing rate of oxytocin neurons. A direct excitatory effect of apelin-13 on vasopressin cell activity is also supported by our in vitro studies showing depolarization of membrane potential and increase in action potential firing. To assess the effects of apelin-13 on somatodendritic peptide release, we used in vitro release studies from SON explants in combination with highly sensitive and specific RIA. Apelin-13 decreases basal (by 78%; P < 0.05; n = 6) and potassium-stimulated (by 57%; P < 0.05; n = 6) vasopressin release but had no effect on somatodendritic oxytocin release. Taken together, our data suggest a local autocrine feedback action of apelin on magnocellular vasopressin neurons. Furthermore, these data show a marked dissociation between axonal and dendritic vasopressin release with a decrease in somatodendritic release but an increase in electrical activity at the cell bodies, indicating that release from these two compartments can be regulated wholly independently.

Oxytocin and appetite.

Oxytocin has potent central effects on feeding behaviour, as well as on social and sexual behaviours, and one likely substrate for its anorectic effect is the ventromedial nucleus of the hypothalamus. This nucleus expresses a high density of oxytocin receptors, but contains very few oxytocin-containing fibres, hence it is a likely target of 'neurohormonal' actions of oxytocin, including possibly oxytocin released from the dendrites of magnocellular oxytocin neurones. As oxytocin release from dendrites is regulated independent of electrical activity and of secretion from the neurohypophysis, exactly how this release is regulated by metabolic and reproduction-related signals remains to be established fully. Intriguingly though, it looks as though this central release of oxytocin from magnocellular neurons might be instrumental in a fundamental shift in motivational behaviour - switching behaviour from being driven by the need to find and consume food, to the need to reproduce.