bluuebunny/crossref_metadata_2025 huggingface dataset:
Extremal bifurcations of rotating AdS4 black holes
Authors: McInnes Brett
Published: December 2021

Abstract

The Weak Gravity Conjecture arises from the assertion that all extremal black holes, even those which are “classical” in the sense of being very massive, must decay by quantum-mechanical emission of particles or smaller black holes. This is interesting, because some observed astrophysical black holes are on the brink of being extremal — though this is due to rapid rotation rather than a large electric or magnetic charge. The possibility that rotating near-extremal black holes might, in addition to radiating spinning particles, also bifurcate by emitting smaller black holes, has attracted much attention of late. There is, however, a basic question to be answered here: can such a bifurcation be compatible with the second law of thermodynamics? This is by no means clear. Here we show that, if there is indeed such a mechanism for bifurcations of AdS4-Kerr-Newman black holes, then this process can in fact satisfy the second law.
Derived representation schemes and Nakajima quiver varieties
Authors: D’Alesio Stefano
Published: December 2021

We introduce a derived representation scheme associated with a quiver, which may be thought of as a derived version of a Nakajima variety. We exhibit an explicit model for the derived representation scheme as a Koszul complex and by doing so we show that it has vanishing higher homology if and only if the moment map defining the corresponding Nakajima variety is flat. In this case we prove a comparison theorem relating isotypical components of the representation scheme to equivariant K-theoretic classes of tautological bundles on the Nakajima variety. As a corollary of this result we obtain some integral formulas present in the mathematical and physical literature since a few years, such as the formula for Nekrasov partition function for the moduli space of framed instantons on$$S^4$$S4. On the technical side we extend the theory of relative derived representation schemes by introducing derived partial character schemes associated with reductive subgroups of the general linear group and constructing an equivariant version of the derived representation functor for algebras with a rational action of an algebraic torus.
Safety and Effectiveness of the New Generation APERIO® Hybrid Stent-retriever Device in Large Vessel Occlusion Stroke
Authors: Vogt Marius L. , Kollikowski Alexander M. , Weidner Franziska , Strinitz Marc , Feick Jörn , Essig Fabian , Neugebauer Hermann , Haeusler Karl Georg , Pham Mirko , Maerz Alexander
Published: December 2021

Background

It is unknown whether technological advancement of stent-retriever devices influences typical observational indicators of safety or effectiveness.

Methods

Observational retrospective study of APERIO® (AP) vs. new generation APERIO® Hybrid (APH) (Acandis®, Pforzheim, Germany) stent-retriever device (01/2019–09/2020) for mechanical thrombectomy (MT) in large vessel occlusion (LVO) stroke. Primary effectiveness endpoint was successful recanalization eTICI (expanded Thrombolysis In Cerebral Ischemia) ≥ 2b67, primary safety endpoint was occurrence of hemorrhagic complications after MT. Secondary outcome measures were time from groin puncture to first pass and successful reperfusion, and the total number of passes needed to achieve the final recanalization result.

Results

A total of 298 patients with LVO stroke who were treated by MT matched the inclusion criteria: 148 patients (49.7%) treated with AP vs. 150 patients (50.3%) treated with new generation APH. Successful recanalization was not statistically different between both groups: 75.7% for AP vs. 79.3% for APH; p = 0.450. Postinterventional hemorrhagic complications and particularly subarachnoid hemorrhage as the entity possibly associated with stent-retriever device type was significantly less frequent in the group treated with the APH: 29.7% for AP and 16.0% for APH; p = 0.005; however, rates of symptomatic hemorrhage with clinical deterioration and in domo mortality were not statistically different. Neither the median number of stent-retriever passages needed to achieve final recanalization, time from groin puncture to first pass, time from groin puncture to final recanalization nor the number of cases in which successful recanalization could only be achieved by using a different stent-retriever as bail-out device differed between both groups.

Conclusion

In the specific example of the APERIO® stent-retriever device, we observed that further technological developments of the new generation device were not associated with disadvantages with respect to typical observational indicators of safety or effectiveness.
Validation of the Thai version of the Prolapse and Incontinence Knowledge Questionnaire (PIKQ)
Authors: Komon Wanchat , Manonai Jittima , Kijmanawat Athasit , Silpakit Chatchawan , Tunkoon Bhatarachit , Jengprasert Ketkaew , Sarit-apirak Sirirat
Published: December 2021

Introduction and hypothesis

The Prolapse and Incontinence Knowledge Questionnaire (PIKQ) was developed and validated to assess women’s knowledge regarding etiology, diagnosis and treatment of pelvic organ prolapse (POP) and urinary incontinence (UI). We aimed to translate and validate a Thai version of the PIKQ to use as a tool to evaluate knowledge of POP and UI among Thai-speaking women.

Methods

The English PIKQ, which comprises the PIKQ-POP and PIKQ-UI sections, was translated into Thai. Psychometric properties of the final version of the Thai PIKQ were tested for content validity, construct validity, internal consistency and test-retest reliability among 168 women attending a gynecology clinic and 150 nurses.

Results

Regarding content validity of the final Thai PIKQ, the number of missing items was 0. Participants in the nurse group were more likely than those in the patient group to select the correct answer for all items for the POP scale and UI scale (P < 0.001). For internal consistency testing, Cronbach’s alpha coefficient was 0.745 for the PIKQ-POP and 0.754 for the PIKQ-UI scales, suggesting that the items had relatively high internal consistency. The item-total correlation values ranged from 0.204 to 0.539, showing an adequate correlation of each item with the scale overall. The correlation coefficients between the test and retest for PIKQ-POP and PIKQ-UI were 0.685 and 0.735, respectively (P < 0.001).

Conclusions

The Thai PIKQ is a simple instrument which shows good validity and high reliability and could be a useful tool for assessing knowledge regarding POP and UI in clinical practice.
Antenatal pelvic floor muscle training and urinary incontinence: a randomized controlled 7-year follow-up study
Authors: Stafne Signe Nilssen , Dalbye Rebecka , Kristiansen Oda M. , Hjelle Yvonne E. , Salvesen Kjell Åsmund , Mørkved Siv , Johannessen Hege Hølmo
Published: December 2021

Introduction and hypothesis

Urinary incontinence is common postpartum. Our aims were to assess whether antenatal exercise including pelvic floor muscle training (PFMT) has long-term effects on urinary incontinence (UI) and to explore factors associated with UI 7 years postpartum.

Methods

A follow-up of a two-centre randomized controlled trial performed at St. Olavs Hospital and Stavanger University Hospital, Norway. In the original trial women were randomized to a 12-week structured exercise protocol including PFMT or standard antenatal care during pregnancy. Link to an electronic questionnaire was sent by postal mail 7 years postpartum. Prevalence of UI was assessed with Sandvik severity index and compared between groups. Factors associated with UI were studied using multivariable logistic regression analysis.

Results

The response rate was 35% (298/855). UI was reported by 78 (51%) in the intervention group and 63 (57%) in the control group (p = 0.539). In the multivariable logistic regression analyses, women with UI at inclusion had a five-fold increase in odds of UI at 7 years (OR 5.4, 95% CI 2.6, 11.5). Engaging in regular exercise was not significantly associated with UI at 7 years; however, UI was associated with lower exercise intensity (OR 2.4, 95% CI 1.2, 4.6).

Conclusions

We found no group differences of antenatal exercise including PFMT on UI after 7 years among the responders. UI in pregnancy increased the risk of long-term UI. Regular exercise was not associated with UI at 7 years; however, women with UI were more than twice as likely to exercise at lower intensity than continent women.
Prevalence, contributory factors and severity of medication errors associated with direct-acting oral anticoagulants in adult patients: a systematic review and meta-analysis
Authors: Al Rowily Abdulrhman , Jalal Zahraa , Price Malcolm J. , Abutaleb Mohammed H. , Almodiaemgh Hind , Al Ammari Maha , Paudyal Vibhu
Published: December 2021

Purpose

This study aimed to estimate the prevalence, contributory factors, and severity of medication errors associated with direct acting oral anticoagulants (DOACs).

Methods

A systematic review and meta-analysis were undertaken by searching 11 databases including Medline, Embase, and CINHAL between January 2008 and September 2020. The pooled prevalence of errors and predictive intervals were estimated using random-effects models using Stata software. Data related to error causation were synthesised according to Reason’s accident causation model.

Results

From the 5205 titles screened, 32 studies were included which were mostly based in hospitals and included DOAC treatment for thromboembolism and atrial fibrillation. The proportion of study population who experienced either prescription, administration, or dispensing error ranged from 5.3 to 37.3%. The pooled percentage of patients experiencing prescribing error was 20% (95% CI 15–25%; I2 = 96%; 95% PrI 4–43%). Prescribing error constituted the majority of all error types with a pooled estimate of 78% (95%CI 73–82%; I2 = 0) of all errors. The common reported causes were active failures including wrong drug, and dose for the indication. Mistakes such as non-consideration of renal function, and error-provoking conditions such as lack of knowledge were common contributing factors. Adverse events such as potentially fatal intracranial haemorrhage or patient deaths were linked to the errors but causality assessments were often missing.

Conclusions

Despite their favourable safety profile, DOAC medication errors are common. There is a need to promote multidisciplinary working, guideline-adherence, training, and education of healthcare professionals, and the use of theory-based and technology-facilitated interventions to minimise errors and maximise the benefits of DOACs usage in all settings.

Protocol

A protocol developed as per PRISMA-P guideline is registered under PROSPERO ID = CRD42019122996
Application of reinforcement learning for the optimization of clinch joint characteristics
Authors: Zirngibl Christoph , Dworschak Fabian , Schleich Benjamin , Wartzack Sandro
Published: December 2021

Due to increasing challenges in the area of lightweight design, the demand for time- and cost-effective joining technologies is steadily rising. For this, cold-forming processes provide a fast and environmentally friendly alternative to common joining methods, such as welding. However, to ensure a sufficient applicability in combination with a high reliability of the joint connection, not only the selection of a best-fitting process, but also the suitable dimensioning of the individual joint is crucial. Therefore, few studies already investigated the systematic analysis of clinched joints usually focusing on the optimization of particular tool geometries against shear and tensile loading. This mainly involved the application of a meta-model assisted genetic algorithm to define a solution space including Pareto optima with all efficient allocations. However, if the investigation of new process configurations (e. g. changing materials) is necessary, the earlier generated meta-models often reach their limits which can lead to a significantly loss of estimation quality. Thus, it is mainly required to repeat the time-consuming and resource-intensive data sampling process in combination with the following identification of best-fitting meta-modeling algorithms. As a solution to this problem, the combination of Deep and Reinforcement Learning provides high potentials for the determination of optimal solutions without taking labeled input data into consideration. Therefore, the training of an Agent aims not only to predict quality-relevant joint characteristics, but also at learning a policy of how to obtain them. As a result, the parameters of the deep neural networks are adapted to represent the effects of varying tool configurations on the target variables. This provides the definition of a novel approach to analyze and optimize clinch joint characteristics for certain use-case scenarios.
The CUSUM statistic of change point under NA sequences
Authors: Ling Jin , Li Xiao-qin , Yang Wen-zhi , Jiao Jian-ling
Published: December 2021

In this paper, we investigate the CUSUM statistic of change point under the negatively associated (NA) sequences. By establishing the consistency estimators for mean and covariance functions respectively, the limit distribution of the CUSUM statistic is proved to be a standard Brownian bridge, which extends the results obtained under the case of an independent normal sample and the moving average processes. Finally, the finite sample properties of the CUSUM statistic are given to show the efficiency of the method by simulation studies and an application on a real data analysis.
Fuzzy Zorn’s lemma with applications
Authors: Xin Xiao-long , Fu Yu-long
Published: December 2021

We introduced the fuzzy axioms of choice, fuzzy Zorn’s lemma and fuzzy well-ordering principle, which are the fuzzy versions of the axioms of choice, Zorn’s lemma and well-ordering principle, and discussed the relations among them. As an application of fuzzy Zorn’s lemma, we got the following results: (1) Every proper fuzzy ideal of a ring was contained in a maximal fuzzy ideal. (2) Every nonzero ring contained a fuzzy maximal ideal. (3) Introduced the notion of fuzzy nilpotent elements in a ring R, and proved that the intersection of all fuzzy prime ideals in a commutative ring R is the union of all fuzzy nilpotent elements in R. (4) Proposed the fuzzy version of Tychonoff Theorem and by use of fuzzy Zorn’s lemma, we proved the fuzzy Tychonoff Theorem.
Assessment of the Antimicrobial and Fertilizing Activity of Table Olive Concentrated Waste Streams During Their Shelf Life
Authors: Brenes Manuel , De Los Santos Berta , Aguado Ana , De Castro Antonio , García Pedro , Romero Concepción
Published: December 2021

Table olive wastewaters represent a big problem for factories not yet solved. Some partial solutions are the purification, the reuse or the generation of a smaller volume of these liquids. The purpose of this study was to investigate the possibility of obtaining a concentrate that can be stable over time and that has a biofertilizing capacity on tomato (Solanum lycopersicum L.) plants. In this study, washing waters from Spanish style green and storage liquids from black ripe olive processing were vacuum concentrated up to 10, 13 and 17 times so that they reached total sugar content of up to 700 mmol L−1, 925 mmol L−1 and 1200 mmol L−1 respectively. Interestingly, the evaporation achieved to retain most of the phenolic compounds that ranged from 18 mmol L−1 in the fresh solution to 140 mmol L−1 in the solution concentrated 10 times. Moreover, these concentrates showed in vitro antimicrobial activity against the bacteria Erwinia amylovora and Pseudomonas syringae, and the Oomycota Phytophthora sp. In addition, they increased the strength and cumulative yield of the tomato plants cultivated under greenhouse conditions, even after 12 months of storage at room temperature. It has been demonstrated that it is possible to reduce the large volume of the wastewaters of the table olive industry, and the concentrates have potential application for agricultural uses, even after 1 year of storage, thereby contributing to a more environmentally sustainable industry.

Graphical Abstract
Stratigraphic architecture and depositional environment of the Paleocene-Lower Eocene aquifers system (Douala onshore basin, SW Cameroon)
Authors: Koah Na Lebogo Serge Parfait , Bisso Dieudonnée , Ngo Elogan Ntem Jeannette , Mvondo Ondoa Joseph
Published: December 2021

The Paleocene-Lower Eocene N'kapa Formation has long been considered as an important groundwater and hydrocarbon resource in the eastern edge of the Douala Basin. The present study’s aim is to establish a possible link between the geological nature of this formation and the quality of potential aquifers using Gamma Ray well log, cuttings and outcrops through sedimentology and sequence stratigraphy studies. The results obtained from this study show that: lithofacies are dominated by clays, silts and sands/sandstones; gamma ray electrofacies are funnel-shaped to cylindrical-shaped with some bell-shaped; depositional environments are continental to shallow marine dominated by fluvial and sometimes tidal processes; fluvial channel-fill, tidal channel-fill and delta front bars sands are potential aquifers; sequence stratigraphy analysis reveals two transgressive–regressive cycles of second order (Danian to Selandian and Thanetian to Ypresian), two Highstand System Tracts, one Transgressive System Tract and one Lowstand System Tract; the high-resolution geometry of these sandy/sandstone sedimentary bodies shows that their distribution is linked to the hydrodynamic factors and the topography of the depositional environment. A total of two types of lithological facies of the reservoir levels were defined according to the volume of clay: clean sandstone (0–15%) and low clayey sandstone (15–30%). The gamma ray well log correlation shows that the thickness of the reservoir levels is variable and that the clay content (Vsh%) increases from the NE to the SW. As a result, the best potential aquifers appear to correspond to the fluvial channel-fill sands deposited during the base-level fall of Upper Paleocene age (Lower Thanetian).
Utilization of produced condensate for enhanced oil recovery: a case study for the forest reserve field in Trinidad
Authors: Lall Daron , Alexander David , Maharaj Rean , Narace Indar , Soroush Mohammad
Published: December 2021

The current global economic trends of low commodity prices for hydrocarbons, competition due to the emergence of shale oil and gas, as well as the decline in production from mature oilfields in Trinidad and Tobago (TT) have fuelled the need for the implementation of efficient and enhanced oil recovery methods. Of particular concern locally is the issue of decreasing oil production and increasing production costs in mature oil fields due to the prevalence of organic deposits (paraffin or asphaltenes), which results in the coating of production tubing causing the plugging of surface equipment, pipelines, perforations and pore spaces in the geological formation. Major deposition compound paraffins and asphaltene are soluble in condensate, which is relatively cheap and is produced as a by-product and flared in TT, and it is already used as a pipeline diluent and cleaner for deposits. The strategy of utilizing this “waste” solvent as an economical and environmentally friendly strategy for EOR was worth investigation. The FR 1346 RD well was selected for evaluation, and a pilot test was conducted using the compositional reservoir simulation model (CMG–GEM). Laboratory studies were conducted using a constructed pressure permeability flow chamber, and results from the device indicated that an asphaltene plug decreased the permeability by approximately 24%, but after treatment with condensate, there was an improvement in permeability of approximately 10% (300 md to 420 md). Tuning of the simulation model incorporating the laboratory-derived permeability data resulted in an increase in production rate to 35 bopd, which matched very closely with the field pilot well test result of an increase of 46% (from 20 to 39 bopd) when the condensate soak was performed. This increase translated in an overall gain of 30,531 bbls of oil associated with a financial gain of approximately $4.7 MM TT per well over the 16-year period. Injection types including condensate, carbon dioxide and nitrogen yielded the production of the same order. This study offers compelling evidence that the use of produced condensate in EOR is an economically and environmentally friendly strategy in TT.
Improvement of a multiphase flow model for wellhead chokes under critical and subcritical conditions using field data
Authors: Leporini Mariella , Terenzi Alessandro , Marchetti Barbara
Published: December 2021

The characterization of the multiphase flow through valves and orifices is a problem yet to be solved in engineering design, and there is a need for a prediction model able to simulate the complexity of this kind of flow in relation to fluid thermodynamic behaviour, and applicable to different incoming stream conditions and compositions. The present paper describes the development of a global model for the calculation of the discharge coefficient of orifices and choke valves operating under two- and three-phase flow as well as critical and subcritical conditions. The model generalizes the hydrovalve model developed by Selmer-Olsen et al. (in: Wilson (ed) Proceedings of 7th international conference on Multiphase Production, BHR Group, pp 441–446, 1995) and the Henry–Fauske (J Heat Transfer 93: 179–187, 1971. 10.1115/1.3449782) non-equilibrium model on the basis of an updated definition of the discharge coefficient. The model has been adapted to real choke valve geometries, by fitting the discharge coefficient and model parameters using field data from three production wells. The model developed is a global quartic function with different constants for the different valve geometries. The new discharge coefficient allows to simulate field data with high accuracy.
Rock property modelling and sensitivity analysis for hydrocarbon exploration in OSSY field, Niger Delta Basin
Authors: Ogbamikhumi Alexander , Omorogieva Osakpolor Marvellous
Published: December 2021

The application of quantitative interpretation techniques for hydrocarbon prospect evaluation from seismic has become so vital. The effective employment of these techniques is dependent on several factors: the quality of the seismic and well data, sparseness of data, the physics of rock, lithological and structural complexity of the field. This study adopts reflection pattern, amplitude versus offset (AVO), Biot–Gassmann fluid substitution and cross-plot models to understand the physics of the reservoir rocks in the field by examining the sensitivity of the basic rock properties; P-wave velocity, S-wave velocity and density, to variation in lithology and fluid types in the pore spaces of reservoirs. This is to ascertain the applicability of quantitative seismic interpretation techniques to explore hydrocarbon prospect in the studied field. The results of reflection pattern and AVO models revealed that the depth of interest is dominated by Class IV AVO sands with a high negative zero offset reflectivity that reduces with offset. The AVO intercept versus gradient plot indicated that both brine and hydrocarbon bearing sands can be discriminated on seismic. Fluid substitution modelling results revealed that the rock properties will favourably respond to variation in oil saturation, but as little as 5% gas presence will result in huge change in the rock properties, which will remain constant upon further increments of gas saturation, thereby making it difficult to differentiate between economical and sub-economical saturations of gas on seismic data. Rock physics cross-plot models revealed separate cluster points typical of shale presence, brine sands and hydrocarbon bearing sands. Thus, the response of the rock properties to the modelling processes adopted favours the application of quantitative interpretation techniques to evaluate hydrocarbon in the field.
In Vitro Studies of a New Method of Flexor Tendon Repair
Authors: SAVAGE ROBERT
Published: December 2021

The mechanical factors in tendon repair have been studied and physical principles applied to this unsolved problem. A new technique of tendon repair has been derived and tested in the laboratory. Compared to several well known techniques it has been shown to have three times the tensile strength and to allow one tenth the gap to form between the tendon ends under load. It has been designed not to constrict the blood supply of the tendon and the tests indicate that it will be strong enough to allow early active mobilisation even after inflammation has caused the tendon to soften.
Tourniquet Pressure: The Effect of Limb Circumference and Systolic Blood Pressure
Authors: VAN ROEKEL H. E. , THURSTON A. J.
Published: December 2021

Complications attributable to direct pressure may result from the use of pneumatic tourniquets during surgical procedures. Traditional estimates have determined the pressures employed rather than the minimal pressure necessary to produce a bloodless field.

To determine this pressure, pre-operative and post-operative systolic blood pressures and the tourniquet pressure at which capillary bleeding occurred were measured in a group of patients undergoing elective surgery of the upper and lower limbs. From these results two equations were derived, one for each of the upper and lower limbs, which give the minimum tourniquet pressures to produce bloodless fields. In an average sized, normotensive patient, 200mm Hg was found to be adequate for the upper limb and 250mm Hg for the lower limb.
Venous Occlusion Plethysmography in Patients with Cold Related Symptoms after Digital Salvage Procedures
Authors: KAY SIMON
Published: December 2021

Fourteen patients who had undergone microsurgical salvage of one or more digits were interviewed and examined. An assessment of sensitivity to cold is defined as cold intolerance and correlated with nerve function and arterial inflow measured by venous occlusion plethysmography. No relationship between arterial inflow and cold intolerance nor nerve function was found. There was, however a tendency for worsening cold intolerance to be associated with poorer nerve function. Half the salvaged digits had arterial inflow greater than the contralateral control digit.
Fractures of the Hook of the Hamate
Authors: FOUCHER G. , SCHUIND F. , MERLE M. , BRUNELLI F.
Published: December 2021

Fractures of the hook of the hamate are rare injuries. Six new cases are presented; the most usual mechanism is probably a direct blow to the area of the hook. The diagnosis, which can only be made by special roentgenographic techniques is usually missed at the acute phase. Most of the cases are diagnosed when painful non-union, fraying tendinitis of the flexor tendons to the ulnar fingers, ulnar or median nerve deficits appear. The adequate treatment is usually excision of the hook fragment.
Irreducible Dislocation of the Distal Interphalangeal Joint
Authors: MURAKAMI Y.
Published: December 2021

A case of irreducible dislocation of the distal interphalangeal joint of the finger caused by entrapment of the deep flexor tendon is reported.
Compound Dislocations of Four Metacarpophalangeal Joints
Authors: WRIGHT C. STEWART
Published: December 2021

A case of compound dorsal dislocation of four metacarpophalangeal joints is presented. The use of early joint motion and extension block splinting resulted in an excellent range of motion in this uncommon injury.
Pseudogout of the Wrist Presenting as Acute Median Nerve Compression
Authors: GOODWIN D. R. A. , ARBEL R.
Published: December 2021

Two cases are reported of acute median nerve compression due to calcium pyrophosphate deposition in the wrist, masquerading as a septic condition.

There have been recent reports in the literature of the effects of calcium pyrophosphate in joints of the upper limb (Resnick 1983 and Hensley, 1983) These conditions are uncommon and the presentation and initial symptomatology of our case led in the first patient to misdiagnosis and an unnecessary operation, which was avoided in the second case.
Preliminary Report on a New Technique to Aid Diagnosis of Some Disorders Found in Hands
Authors: WALLACE R. G. H. , MOLLAN R. A. B. , KERNOHAN W. G.
Published: December 2021

This preliminary report proposes to show that an objective auscultatory method exists as an aid to diagnosis of some hand conditions. The signals so produced are both distinctive and reproducible. The conditions investigated were:- Cavitation finger clicks; Trigger finger; normal crepitus and the crepitus of de Quervain’s tenosynovitis.
Finger Reconstruction Using Toe Transplantation
Authors: LEUNG P. C.
Published: December 2021

In the mutilated hand where all the fingers are destroyed, the undamaged mobile thumb will not be capable of performing the important function of making a grip or pinch alone. Under such circumstances, it is worthwhile reconstructing the missing fingers so as to restore this simple but basic function.
Irreducible Compound Dorsal Dislocations of the Proximal Interphalangeal Joint of the Finger
Authors: KJELDAL INGER
Published: December 2021

Three cases of compound irreducible dorsal dislocation of the proximal interphalangeal joint of the finger are reported. The probable mechanism is discussed. The findings warrant the description “volar capsular boutonnière” as the condyles of the proximal phalanx buttonhole, through the volar structures.

Open reduction combined with debridement, is the treatment for such compound irreducible dorsal dislocations.

Dislocation of the proximal interphalangeal joints of the fingers are common and can usually be reduced by simple traction. Occasionally reduction by closed methods is unsuccessful because of interposition of volar or dorsal soft tissue structures (Lamb 1981).

This study reports three cases of compound dorsal dislocation of the proximal interphalangeal joint with volar soft tissue interposition.

Such lesions are sparsely mentioned in text books on fractures and hand injuries and hitherto only a few cases have been published (Lamb 1981, Bunnell 1956).
Volar Dislocation of the Metacarpophalangeal Joint of the Thumb—A Case Report
Authors: MIYAMOTO M. , HIRAYAMA T. , UCHIDA M.
Published: December 2021

A patient with a volar dislocation of the metacarpophalangeal joint of the thumb is reported in which closed reduction proved impossible because of the interposition of the dorsal capsule, extensor pollicis longus tendon and extensor pollicis brevis tendon in the metacarpophalangeal joint. The collateral ligament was also ruptured. Therefore open reduction is recommended for similar cases.
Primary Flexor Tendon Repair: The Mechanical Limitations of the Modified Kessler Technique
Authors: WADE P. J. F. , MUIR I. F. K. , HUTCHEON L. L.
Published: December 2021

The aim of primary suture of flexor tendons in the hand is to achieve full function as soon as possible with a one stage operation. Much interest has been aroused by this subject and more recently by the possibility of improving results by postoperative active movement of the repaired tendon. We report the results of mechanical testing of the modified Kessler suture which suggests that the peripheral stitch is an important structural component of the suture. It is not merely a 'tucking in' stitch, but is essential to prevent very early gap formation. Steel is the best material for the central or core part of the suture. Cautious active postoperative movements may be possible using the modified Kessler suture, but within a narrow range of safety and with careful supervision.
The Excursions of the Long Extensor Tendons of the Hand
Authors: ELLIOT D. , McGROUTHER D. A.
Published: December 2021

In a cadaveric study in seven hands, the mathematical relationship between extensor tendon excursion and joint motion (wrist, m.p., p.i.p. and d.i.p.) has been investigated. This has been found to be linear at all joints, allowing the mean tendon excursions corresponding to ten degrees of joint motion to be calculated for each of the above joints for all five rays of the hand. A table of these excursion values is presented as a reference for calculation of clinical problems.
Compressed Air Injuries of the Hand
Authors: KLARESKOV B. , GEBUHR P. , RØRDAM P.
Published: December 2021

Two cases of injection of compressed air into the hand are reported. The air was injected under a pressure of 5–15 Atm. Both cases had a benign course. This is in contrast to high pressure injection (40–400 Atm) with foreign material.

Both patients had minor skin lesions before the accident.
Ulnar Variance in Kienböck’s Disease
Authors: KRISTENSEN S. S. , THOMASSEN E. , CHRISTENSEN F.
Published: December 2021

Forty four patients with forty seven wrists suffering from Kienböck’s disease were re-examined. The mean observation time was 20.5 years. In all forty seven wrists the treatment had been immobilization. Using a standard X-ray projection, and a reliable method of ulnar variance measuring, the ulnar variance was determined by three observers independently. Comparing the result with the ulnar variance in normal wrists we found the so-called “ulnar minus variant” overrepresented in patients with Kienböck’s disease. However, comparing X-rays taken at the time of diagnosis with X-rays at re-examination, we found in eight out of forty seven wrists that a subchondral bone formation in the distal radius opposite the lunate bone had taken place. This bone formation will tend to enhance the negative value of ulnar variance measurements, and suggests an explanation of the overrepresentation of “ulnar minus variants” in Kienböck’s disease. Excluding these eight wrists from the material and comparing the mean ulnar variance value in the remaining thirty nine wrists with the mean value in normal wrists no statistical difference was shown. Based on these observations it seems unlikely that the “ulnar minus variant” has any bearing on the cause of Kienböck’s disease.
Dynamic Splinting Following Flexor Tendon Repair
Authors: CITRON N. D. , FORSTER A.
Published: December 2021

Electromyographic investigation of subjects wearing dynamic flexor tendon repair (Kleinert) splints shows a wide variability in the amount of contraction in the flexor digitorum profundus muscle during extension of the finger. We suggest there is no advantage in giving extra resistance to the extensor muscles, and that the strength of the rubber bands needs to be only just sufficient to flex the finger passively back to its resting position.
Treatment of Ganglia by a Thread Technique
Authors: GANG R. K. , MAKHLOUF S.
Published: December 2021

Seventy ganglia of the wrist have been treated by a new method whereby two sutures are passed through the ganglion, at right angles to each other, and each is tied in a loop. At intervals thereafter, the contents of the ganglion are expelled by massage. Only three recurrences occurred in 62 patients followed-up. This compares well with the results of surgical excision and avoids the complications of operation and anaesthetic.
Kienböck’s Disease: Two Unusual Cases
Authors: RIBBANS W. J.
Published: December 2021

Two unusual cases of Kienböck’s disease are reported. The first is of a young woman whose presenting feature was spontaneous rupture of the flexor pollicis longus tendon. This is the first reported case in which such a rupture was the presenting feature of the condition. The second of a 71-year-old woman with scleroderma and Raynaud’s disease who did not develop Kienböck’s disease until late in life. The literature contains no older patient with this condition and a likely association is made between the avascular necrosis and the vasculitis associated wit this connective tissue disorder.
Forearm Muscle Herniae and their Treatment
Authors: ROBERTS J. O. , REGAN P. J. , DICKINSON J. C. , BAILEY B. N.
Published: December 2021

Three cases of forearm muscle hernia are described. Their aetiology differed but, in all three, symptoms were sufficiently severe to interfere with the patient’s work. Surgical repair of the myocoeles, by closure of the fascial defects using fascia lata onlay grafts or an interweave of palmaris longus tendon, produced complete resolution of symptoms and enabled the patients to return to full employment.
The Scaphoid Compression Test
Authors: CHEN S. C.
Published: December 2021

A clinical test for scaphoid waist fractures is described in which the first ray is compressed longitudinally. This has the advantage that it can be done when the patient is in a plaster cast. Of 52 patients with suspected scaphoid fractures, 37 had negative tests and proved by X-rays then and later to have no fracture. 12 had positive tests and X-rays. Two patients with positive tests had fractures nearby: one of the scaphoid tuberosity and one of the radial styloid. One patient with a negative test had de Quervain’s disease. Once union has occurred, the test becomes negative.
Carpal Malalignment in Colles’ Fractures
Authors: BICKERSTAFF D. R. , BELL M. J.
Published: December 2021

Thirty-two unilateral Colles’ fractures were reviewed after one year to assess the evidence for carpal malalignment. Various radiographic parameters on the injured and uninjured wrists were correlated with a functional score. There was significant correlation with respect to the angles measuring carpal alignment on the late films and the functional score which was not present on either the initial or post-manipulation films. The carpus aligns in a dorsal instability pattern. Radial angulation or shortening was not found to be as significant in either the early or late films. This suggests that dorsal instability as the cause of morbidity after Colles’ fracture is far commoner than originally thought.
Haematoma Block for Fractures of the Wrist: A Cause of Compartment Syndrome
Authors: YOUNGE D.
Published: December 2021

A case of compartment syndrome after haematoma block for a fracture of the distal radius is reported. This seems to be the first report of this complication. A review of the literature revealed seven other cases of compartmental ischaemia reported after fracture of the distal radius, and a haematoma block was used in all the cases where the type of anaesthesia was known. It is suggested that the additional fluid added for a haematoma block can precipitate a compartment syndrome, which may be more common than the scarcity of cases reported would indicate.
Homodigital Neurovascular Island Flaps for Digital Pulp Loss
Authors: FOUCHER G. , SMITH D. , PEMPINELLO C. , BRAUN F. M. , CITRON N.
Published: December 2021

Terminal amputations with loss of the distal pulp are common injuries. This report analyses 64 consecutive cases of advanced or exchanged homodigital neurovascular island flaps operated on by one surgeon between 1981–1986. The surgical technique, indications, contra-indications and five year results are evaluated. Overall, these flaps provide reliable vascularity as well as normal sensibility at the distal end of the finger where high quality perception is required.
Surgical Catgut: The Myth of Allergy
Authors: CARROLL R. E.
Published: December 2021

During the period 1950 to 1985, 137 patients stated to the author that they were allergic to catgut sutures. The allegations were based on a previous episode at various sites on the body where wound healing had been complicated. A review of the problem did not indicate any history of symptoms of allergy. The author used catgut in the completion of his surgery on each of these patients. None of them showed any allergic manifestation and all healed perfectly per primum. Recent molecular studies of the collagen proteins demonstrate that it is highly improbable for the material to cause antigenicity.
Flexor Tendon Repair: Significant Gain in Strength from the Halsted Peripheral Suture Technique
Authors: WADE P. J. F. , WETHERELL R. G. , AMIS A. A.
Published: December 2021

A biomechanical study in vitro has evaluated a new modification of the core and peripheral suture technique for flexor tendon repair. Groups of repairs were conducted in cadaver tendons, using a core suture alone, a core suture with a simple running surface suture and a new modification involving a ‘Halsted’ horizontal mattress technique for the peripheral stitch. The Halsted modification increased the load at which a visible gap formed by 93%, the load at which a 2 mm gap formed by 77%, and the maximum strength by 89%. This increase was due to the technique; it did not depend on the suture material used. The bulk of the tendon repair was not significantly greater with the Halsted modification.
The Independent Long Extensor Tendon of the Fifth Toe as a Source of Tendon Grafts for the Hand
Authors: AULICINO P. L. , AINSWORTH S. R. , PARKER M.
Published: December 2021

The anatomical relationships of the extensor of the fifth toe to the long extensor of the other toes have been studied in 78 cadaver specimens. 50% of the specimens had an independent extensor to the fifth toe without interconnections to the other long toe extensors or the peroneus tertius. The independent fifth toe extensor was consistently of good quality and adequate length for use as a tendon graft, for which purpose it has been successfully used in five patients, with transfer of the adjacent long extensor from the fourth toe to maintain extension of the fifth metatarso-phalangeal joint.
The Sesamoids of the Metacarpo-Phalangeal Joint of the Thumb: An Anatomical and Clinical Study
Authors: GIBEAULT J. D. , SABA P. , HOENECKE H. , GRAHAM A.
Published: December 2021

Two unusual cases of injury to the sesamoids of the M.P. joint of the thumb are described. An anatomical dissection of the M.P. volar plate region, including the sesamoids, was undertaken to delineate the details of the sesamoids’ relationship to the M.P. joint, flexor tendon, flexor tendon sheath and capsule of the joint. Histological studies were carried out to demonstrate a tendinous extension of the muscles that attach to the sesamoids.
Surgical Emphysema of the Dorsum of the Hand
Authors: BUTT M. , HIRD G. F.
Published: December 2021

We report a case of surgical emphysema of the dorsum of the hand following an injury when a hawthorn penetrated into the subcutaneous tissues over the dorsum of the M.P. joint of the ring finger.
Bennett’s Fracture
Authors: KJÆR-PETERSEN K. , LANGHOFF O. , ANDERSEN K.
Published: December 2021

The relationship between the quality of redaction and the occurrence of arthritic changes, symptoms and disability was studied in 41 Bennett’s fractures. Excellent position was obtained in five of nine fractures treated by closed reduction and plaster immobilisation, in four of six fractures treated by percutaneous K wire fixation and in 18 of 26 fractures treated by open reduction. After a median interval of 7.3 years, 15 of 18 reviewed patients with fractures healed in excellent position were free of symptoms, but this was so in only six of 13 fractures with residual displacement. The remainder had intermittent slight pain. Radiographic signs of arthritis was found in ten of 24 patients: three of 14 patients with excellent reduction and seven of ten patients with residual displacement.
Interphalangeal Dislocations of the Fingers Treated by an Elastic Double-Finger Bandage
Authors: SOELBERG M. , GEBUHR P. , KLARESKOV B.
Published: December 2021

A prospective trial of dislocations of the interphalangeal joints of fingers treated by elastic double-finger bandage showed good final results with an almost normal range of motion. The method is found pleasant by the patient, being hygienic and causing no kind of skin reaction.
Extensor Tendon Repair: An Animal Model Which Allows Immediate Post-Operative Mobilisation
Authors: WILSON KAREN , MOORE M. J. , RAYNER C. R. , FENTON O. M.
Published: December 2021

In adult rabbits, an experimentally transected digital extensor tendon was repaired. The technique employed a tongue, created from the proximal tendon, folded over to bridge the transection and reattached distally. Animals were allowed immediate post-operative mobilisation. Tendon material, 14–120 days post-operatively, was examined ultrastructurally in control and experimental animals from four different zones within the repaired tendon. The operation was well tolerated and adhesion free. Associated with the repair, two types of collagen fibril populations were observed. Firstly, in areas where tendon tissue had been removed, there was a population of fibrils with a narrow range of diameters. Secondly, in areas where tendon tissue was subjected to an increased level of stress per unit cross-sectional area, a population of fibrils with a range of diameters similar to that of controls but with a marked increase in the percentage of small diameter fibrils. The relevance of these observations to human tendon repair is discussed.
Location of Impaired Sensory Conduction of the Median Nerve in Carpal Tunnel Syndrome
Authors: NATHAN P. A. , SRINIVASAN H. , DOYLE LINDA S. , MEADOWS K. D.
Published: December 2021

Sensory conduction of the median nerve at the carpal tunnel for eight consecutive 1 cm segments of the nerve was evaluated in 217 hands of 153 of our patients with carpal tunnel syndrome. Impairment was found to be highly focal and often confined to a single 1 cm segment of the nerve. The section of the nerve at or just distal to the distal margin of the carpal tunnel was affected most frequently, the section within the tunnel was affected less often, and the section proximal to the tunnel at the level of the mid-carpal and radio-carpal joints was affected least. The greatest contrast between frequencies of slowing at adjacent segments occurred at the proximal and distal margins of the carpal tunnel. The distribution of the nerve impairment was similar between the sexes; however, among the men the segment affected most frequently was located 1 cm distal to the segment affected most frequently among the women. The general pattern of slowing which we found does not substantiate some commonly-held opinions about the aetiology of carpal tunnel syndrome.
Acute Ischaemia of the Hand Following Accidental Radial Artery Infusion of Depo-Medrone
Authors: TAWEEPOKE P. , FRAME J. D.
Published: December 2021

Acute ischaemia of the hand following the accidental intra-arterial injection of steroid has not, to our knowledge, been previously reported. We present such a case of the injection of Depo-Medrone with Lidocaine (Upjohn) into the right radial artery during attempted treatment of stenosing tenosynovitis of the right thumb. The resultant acute ischaemia was successfully managed after 20 hours by a combination of surgical thrombectomy, intra-arterial streptokinase and intravenous heparin and thymoxamine.
Complete Detachment of the Epiphysis of the Distal Phalanx
Authors: SAVAGE R.
Published: December 2021

A case of fracture-separation of the distal phalanx epiphysis, with complete detachment from soft tissue, is reported and discussed.
Congenital Malformations of the Hand
Authors: HADIDI A. T. , KADDAH N. T. , ZAKI M. S. , SAMI A. , AAL N. A.
Published: December 2021

Sixty-five children with 76 hand anomalies had brachial angiography performed to help plan appropriate surgical management. Three different methods of angiography were used. The study showed that the direct exposure method is safe and simple, has few complications and gives the best visualisation of the arterial supply of the hand. It also showed that each type of congenital hand deformity is frequently associated with specific vascular alterations. Angiography is an important and safe investigation in the pre-operative assessment of cases of complex congenital hand deformities.