Perioperative administration of tranexamic acid in hip fracture surgery (The PATHS study): national audit of current practice

INTRODUCTION

Neck of femur fractures (NOFF) are associated with significant morbidity and mortality, exacerbated by anaemia. Evidence indicates tranexamic acid (TXA) administration in NOFF surgery reduces blood loss and transfusion requirements, without increasing complications. The aim of this study was to establish current TXA administration practice in patients undergoing surgery for NOFF in the UK.

METHODS

We conducted a multicentre prospective study within the UK over a two-week period in March 2019. Pre-, intra- and postoperative data were collected locally and analysed centrally.

RESULTS

Data for 917 patients were submitted from 66 institutions. Of those eligible, 48.0% received TXA perioperatively. Administration rates varied from 0 to 100%. Significantly greater numbers undergoing arthroplasty received TXA (57.6%) compared with internal fixation (38.4%, p<0.01). Some 15.2% of institutions had a protocol for TXA use in NOFF. Patients treated in these units were significantly more likely to receive TXA (86.7%) than those who were not (41.2% p<0.01). Of those receiving TXA, 92.3% were given 1g intravenously (IV) at anaesthetic administration.

CONCLUSIONS

Despite supportive evidence for its use, a wide variation in the administration of TXA between hospitals and procedures has been demonstrated. Administration rates were higher for arthroplasty than for fixation procedures. Most centres do not have a protocol guiding TXA administration. We recommend administration of 1g IV TXA perioperatively for patients undergoing NOFF surgery, where not contraindicated, unless future randomised controlled trials support an alternative regimen. We recommend units include their own locally agreed TXA policy within a written protocol for the care of NOFF patients.

NEOTROPICAL FRESHWATER FISHES: A dataset of occurrence and abundance of freshwater fishes in the Neotropics

The Neotropical region hosts 4225 freshwater fish species, ranking first among the world's most diverse regions for freshwater fishes. Our NEOTROPICAL FRESHWATER FISHES data set is the first to produce a large-scale Neotropical freshwater fish inventory, covering the entire Neotropical region from Mexico and the Caribbean in the north to the southern limits in Argentina, Paraguay, Chile, and Uruguay. We compiled 185,787 distribution records, with unique georeferenced coordinates, for the 4225 species, represented by occurrence and abundance data. The number of species for the most numerous orders are as follows: Characiformes (1289), Siluriformes (1384), Cichliformes (354), Cyprinodontiformes (245), and Gymnotiformes (135). The most recorded species was the characid Astyanax fasciatus (4696 records). We registered 116,802 distribution records for native species, compared to 1802 distribution records for nonnative species. The main aim of the NEOTROPICAL FRESHWATER FISHES data set was to make these occurrence and abundance data accessible for international researchers to develop ecological and macroecological studies, from local to regional scales, with focal fish species, families, or orders. We anticipate that the NEOTROPICAL FRESHWATER FISHES data set will be valuable for studies on a wide range of ecological processes, such as trophic cascades, fishery pressure, the effects of habitat loss and fragmentation, and the impacts of species invasion and climate change. There are no copyright restrictions on the data, and please cite this data paper when using the data in publications.

Macroinfauna responses and recovery trajectories after an oil spill differ from those following saltmarsh restoration

Given the severity of injuries to biota in coastal wetlands from the Deepwater Horizon oil spill (DWH) and the resulting availability of funding for restoration, information on impacted salt marshes and biotic development of restored marshes may both help inform marsh restoration planning in the near term and for future spills. Accordingly, we performed a meta-analysis to model a restoration trajectory of total macroinfauna density in constructed marshes (studied for ~30 y), and with a previously published restoration trajectory for amphipods, we compared these to recovery curves for total macroinfauna and amphipods from DWH impacted marshes (over 8.5 y). Total macroinfauna and amphipod densities in constructed marshes did not consistently reach equivalency with reference sites before 20 y, yet in heavily oiled marshes recovery occurred by 4.5 y post spill (although it is unlikely that macroinfaunal community composition fully recovered). These differences were probably due to initial conditions (e.g., higher initial levels of belowground organic matter in oiled marshes) that were more conducive to recovery as compared to constructed marshes. Furthermore, we found that amphipod trajectories were distinctly different in constructed and oiled marshes as densities at oiled sites exceeded that of reference sites by as much as 20x during much of the recovery period. Amphipods may have responded to the rapid increase and high biomass of benthic microalgae following the spill. These results indicate that biotic responses after an oil spill may be quantitatively different than those following restoration, even for heavily oiled marshes that were initially denuded of vegetation. Our dual trajectories for oil spill recovery and restoration development for macroinfauna should help guide restoration planning and assessment following the DWH as well as for restoration scaling for future spills.

Search for Subsolar Mass Ultracompact Binaries in Advanced LIGO's Second Observing Run

We present a search for subsolar mass ultracompact objects in data obtained during Advanced LIGO's second observing run. In contrast to a previous search of Advanced LIGO data from the first observing run, this search includes the effects of component spin on the gravitational waveform. We identify no viable gravitational-wave candidates consistent with subsolar mass ultracompact binaries with at least one component between 0.2  M_{⊙}-1.0  M_{⊙}. We use the null result to constrain the binary merger rate of (0.2  M_{⊙}, 0.2  M_{⊙}) binaries to be less than 3.7×10^{5}  Gpc^{-3} yr^{-1} and the binary merger rate of (1.0  M_{⊙}, 1.0  M_{⊙}) binaries to be less than 5.2×10^{3}  Gpc^{-3} yr^{-1}. Subsolar mass ultracompact objects are not expected to form via known stellar evolution channels, though it has been suggested that primordial density fluctuations or particle dark matter with cooling mechanisms and/or nuclear interactions could form black holes with subsolar masses. Assuming a particular primordial black hole (PBH) formation model, we constrain a population of merging 0.2  M_{⊙} black holes to account for less than 16% of the dark matter density and a population of merging 1.0  M_{⊙} black holes to account for less than 2% of the dark matter density. We discuss how constraints on the merger rate and dark matter fraction may be extended to arbitrary black hole population models that predict subsolar mass binaries.

Tests of General Relativity with GW170817

The recent discovery by Advanced LIGO and Advanced Virgo of a gravitational wave signal from a binary neutron star inspiral has enabled tests of general relativity (GR) with this new type of source. This source, for the first time, permits tests of strong-field dynamics of compact binaries in the presence of matter. In this Letter, we place constraints on the dipole radiation and possible deviations from GR in the post-Newtonian coefficients that govern the inspiral regime. Bounds on modified dispersion of gravitational waves are obtained; in combination with information from the observed electromagnetic counterpart we can also constrain effects due to large extra dimensions. Finally, the polarization content of the gravitational wave signal is studied. The results of all tests performed here show good agreement with GR.

Constraining the p-Mode-g-Mode Tidal Instability with GW170817

We analyze the impact of a proposed tidal instability coupling p modes and g modes within neutron stars on GW170817. This nonresonant instability transfers energy from the orbit of the binary to internal modes of the stars, accelerating the gravitational-wave driven inspiral. We model the impact of this instability on the phasing of the gravitational wave signal using three parameters per star: an overall amplitude, a saturation frequency, and a spectral index. Incorporating these additional parameters, we compute the Bayes factor (lnB_{!pg}^{pg}) comparing our p-g model to a standard one. We find that the observed signal is consistent with waveform models that neglect p-g effects, with lnB_{!pg}^{pg}=0.03_{-0.58}^{+0.70} (maximum a posteriori and 90% credible region). By injecting simulated signals that do not include p-g effects and recovering them with the p-g model, we show that there is a ≃50% probability of obtaining similar lnB_{!pg}^{pg} even when p-g effects are absent. We find that the p-g amplitude for 1.4  M_{⊙} neutron stars is constrained to less than a few tenths of the theoretical maximum, with maxima a posteriori near one-tenth this maximum and p-g saturation frequency ∼70  Hz. This suggests that there are less than a few hundred excited modes, assuming they all saturate by wave breaking. For comparison, theoretical upper bounds suggest ≲10^{3} modes saturate by wave breaking. Thus, the measured constraints only rule out extreme values of the p-g parameters. They also imply that the instability dissipates ≲10^{51}  erg over the entire inspiral, i.e., less than a few percent of the energy radiated as gravitational waves.

Search for Subsolar-Mass Ultracompact Binaries in Advanced LIGO's First Observing Run

We present the first Advanced LIGO and Advanced Virgo search for ultracompact binary systems with component masses between 0.2  M_{⊙}-1.0  M_{⊙} using data taken between September 12, 2015 and January 19, 2016. We find no viable gravitational wave candidates. Our null result constrains the coalescence rate of monochromatic (delta function) distributions of nonspinning (0.2  M_{⊙}, 0.2  M_{⊙}) ultracompact binaries to be less than 1.0×10^{6}  Gpc^{-3}  yr^{-1} and the coalescence rate of a similar distribution of (1.0  M_{⊙}, 1.0  M_{⊙}) ultracompact binaries to be less than 1.9×10^{4}  Gpc^{-3}  yr^{-1} (at 90% confidence). Neither black holes nor neutron stars are expected to form below ∼1  M_{⊙} through conventional stellar evolution, though it has been proposed that similarly low mass black holes could be formed primordially through density fluctuations in the early Universe and contribute to the dark matter density. The interpretation of our constraints in the primordial black hole dark matter paradigm is highly model dependent; however, under a particular primordial black hole binary formation scenario we constrain monochromatic primordial black hole populations of 0.2  M_{⊙} to be less than 33% of the total dark matter density and monochromatic populations of 1.0  M_{⊙} to be less than 5% of the dark matter density. The latter strengthens the presently placed bounds from microlensing surveys of massive compact halo objects (MACHOs) provided by the MACHO and EROS Collaborations.

GW170817: Measurements of Neutron Star Radii and Equation of State

On 17 August 2017, the LIGO and Virgo observatories made the first direct detection of gravitational waves from the coalescence of a neutron star binary system. The detection of this gravitational-wave signal, GW170817, offers a novel opportunity to directly probe the properties of matter at the extreme conditions found in the interior of these stars. The initial, minimal-assumption analysis of the LIGO and Virgo data placed constraints on the tidal effects of the coalescing bodies, which were then translated to constraints on neutron star radii. Here, we expand upon previous analyses by working under the hypothesis that both bodies were neutron stars that are described by the same equation of state and have spins within the range observed in Galactic binary neutron stars. Our analysis employs two methods: the use of equation-of-state-insensitive relations between various macroscopic properties of the neutron stars and the use of an efficient parametrization of the defining function p(ρ) of the equation of state itself. From the LIGO and Virgo data alone and the first method, we measure the two neutron star radii as R_{1}=10.8_{-1.7}^{+2.0}  km for the heavier star and R_{2}=10.7_{-1.5}^{+2.1}  km for the lighter star at the 90% credible level. If we additionally require that the equation of state supports neutron stars with masses larger than 1.97  M_{⊙} as required from electromagnetic observations and employ the equation-of-state parametrization, we further constrain R_{1}=11.9_{-1.4}^{+1.4}  km and R_{2}=11.9_{-1.4}^{+1.4}  km at the 90% credible level. Finally, we obtain constraints on p(ρ) at supranuclear densities, with pressure at twice nuclear saturation density measured at 3.5_{-1.7}^{+2.7}×10^{34}  dyn cm^{-2} at the 90% level.

Is the number of new trauma and orthopaedic consultant posts increasing or decreasing?

Introduction Trauma and orthopaedics is a popular surgical specialty in the UK. Recent changes to the National Health Service have suggested an imbalance with fewer jobs yet more trainees. Furthermore, subspecialisation is emerging within all surgical disciplines. The aim of this study was to examine whether there were decreasing numbers of trauma and orthopaedic (T&O) consultant appointments in the UK, and to determine the frequency of subspecialisation. Methods All 51 issues of the British Medical Journal (BMJ) careers supplement from the year 2000 were reviewed as well as the 51 issues from 2010. The number of T&O posts, requested subspecialty interests and the number of posts in other surgical specialties were analysed. Results A total of 481 consultant posts in T&O were advertised in the 102 issues of the careers supplements reviewed. Of these, 281 were advertised in 2000 and 200 in 2010. The mean number of posts per issue was 5.5 in 2000 and 3.9 in 2010. In 2000 orthopaedic posts represented 30.5% of all surgical posts while in 2010 this was 37.8%. Under two-thirds (61.6%) of posts requested a specialty interest in 2000 but this increased to 93% in 2010. The greatest increase in named subspecialty was seen in 'spine' (from 4.1% to 19.0%.) while 'general' had the greatest decrease (from 38.4% to 7.0%). Conclusions UK consultant posts in T&O are decreasing in frequency. Most advertised posts request a subspecialty interest but registrar training focuses on producing 'generally' competent orthopaedic consultants. The onus is therefore on fellowships to develop subspecialty interest. As these are not all educationally approved, reconfiguration of fellowships is likely to be necessary.

Chitayat syndrome: hyperphalangism, characteristic facies, hallux valgus and bronchomalacia results from a recurrent c.266A>G p.(Tyr89Cys) variant in the ERF gene

BACKGROUND

In 1993, Chitayat et al., reported a newborn with hyperphalangism, facial anomalies, and bronchomalacia. We identified three additional families with similar findings. Features include bilateral accessory phalanx resulting in shortened index fingers; hallux valgus; distinctive face; respiratory compromise.

OBJECTIVES

To identify the genetic aetiology of Chitayat syndrome and identify a unifying cause for this specific form of hyperphalangism.

METHODS

Through ongoing collaboration, we had collected patients with strikingly-similar phenotype. Trio-based exome sequencing was first performed in Patient 2 through Deciphering Developmental Disorders study. Proband-only exome sequencing had previously been independently performed in Patient 4. Following identification of a candidate gene variant in Patient 2, the same variant was subsequently confirmed from exome data in Patient 4. Sanger sequencing was used to validate this variant in Patients 1, 3; confirm paternal inheritance in Patient 5.

RESULTS

A recurrent, novel variant NM_006494.2:c.266A>G p.(Tyr89Cys) in ERF was identified in five affected individuals: de novo (patient 1, 2 and 3) and inherited from an affected father (patient 4 and 5). p.Tyr89Cys is an aromatic polar neutral to polar neutral amino acid substitution, at a highly conserved position and lies within the functionally important ETS-domain of the protein. The recurrent ERF c.266A>C p.(Tyr89Cys) variant causes Chitayat syndrome.

DISCUSSION

ERF variants have previously been associated with complex craniosynostosis. In contrast, none of the patients with the c.266A>G p.(Tyr89Cys) variant have craniosynostosis.

CONCLUSIONS

We report the molecular aetiology of Chitayat syndrome and discuss potential mechanisms for this distinctive phenotype associated with the p.Tyr89Cys substitution in ERF.

Development of bingeing in rats altered by a small operant requirement

Previous studies have shown that providing an optional food for a brief period of time to non-food deprived rats on an intermittent basis in the home cage engenders significantly more intake (binge-type behavior) than when the optional food is provided for a brief period on a daily basis. Experiment 1 examined the effects of placing a small operant response requirement on access to an optional food (vegetable shortening) on the establishment of binge-type behavior. Experiment 2 examined the effects of different schedules of reinforcement, a period of abstinence from shortening, and 24h of food deprivation on established binge-type behavior. In Experiment 1 the group of rats with 30-min access to shortening on an intermittent basis in their home cages (IC) consumed significantly more shortening than the group with 30-min daily access in the home cage (DC). The group with 30-min intermittent access in an operant chamber (IO group) earned significantly more reinforcers than the group with 30-min daily access in an operant chamber (DO). In Experiment 2, the IO group earned significantly more reinforcers than the DO group regardless of the response cost, the period of shortening abstinence, and overnight food deprivation. These results demonstrate that while intermittent access generates binge-type eating, the size of the binge (intake) can be altered by different contingency arrangements.

Comprehensive analysis of karyotypic mosaicism between trophectoderm and inner cell mass

Aneuploidy has been well-documented in blastocyst embryos, but prior studies have been limited in scale and/or lack mechanistic data. We previously reported preclinical validation of microarray 24-chromosome preimplantation genetic screening in a 24-h protocol. The method diagnoses chromosome copy number, structural chromosome aberrations, parental source of aneuploidy and distinguishes certain meiotic from mitotic errors. In this study, our objective was to examine aneuploidy in human blastocysts and determine correspondence of karyotypes between trophectoderm (TE) and inner cell mass (ICM). We disaggregated 51 blastocysts from 17 couples into ICM and one or two TE fractions. The average maternal age was 31. Next, we ran 24-chromosome microarray molecular karyotyping on all of the samples, and then performed a retrospective analysis of the data. The average per-chromosome confidence was 99.95%. Approximately 80% of blastocysts were euploid. The majority of aneuploid embryos were simple aneuploid, i.e. one or two whole-chromosome imbalances. Structural chromosome aberrations, which are common in cleavage stage embryos, occurred in only three blastocysts (5.8%). All TE biopsies derived from the same embryos were concordant. Forty-nine of 51 (96.1%) ICM samples were concordant with TE biopsies derived from the same embryos. Discordance between TE and ICM occurred only in the two embryos with structural chromosome aberration. We conclude that TE karyotype is an excellent predictor of ICM karyotype. Discordance between TE and ICM occurred only in embryos with structural chromosome aberrations.

Preclinical validation of a microarray method for full molecular karyotyping of blastomeres in a 24-h protocol

BACKGROUND

Preimplantation genetic screening (PGS) has been used in an attempt to determine embryonic aneuploidy. Techniques that use new molecular methods to determine the karyotype of an embryo are expanding the scope of PGS.

METHODS

We introduce a new method for PGS, termed 'parental support', which leverages microarray measurements from parental DNA to 'clean' single-cell microarray measurements on embryonic cells and explicitly computes confidence in each copy number call. The method distinguishes mitotic and meiotic copy errors and determines parental source of aneuploidy.

RESULTS

Validation with 459 single cells of known karyotype indicated that per-cell false-positive and false-negative rates are roughly equivalent to the 'gold standard' metaphase karyotype. The majority of the cells were run in parallel with a clinical commercial PGS service. Computed confidences were conservative and roughly concordant with accuracy. To examine ploidy in human embryos, the method was then applied to 26 disaggregated, cryopreserved, cleavage-stage embryos for a total of 134 single blastomeres. Only 23.1% of the embryos were euploid, though 46.2% of embryos were mosaic euploid. Mosaicism affected 57.7% of the embryos. Counts of mitotic and meiotic errors were roughly equivalent. Maternal meiotic trisomy predominated over paternal trisomy, and maternal meiotic trisomies were negatively predictive of mosaic euploid embryos.

CONCLUSIONS

We have performed a major preclinical validation of a new method for PGS and found that the technology performs approximately as well as a metaphase karyotype. We also directly measured the mechanism of aneuploidy in cleavage-stage human embryos and found high rates and distinct patterns of mitotic and meiotic aneuploidy.

Access conditions affect binge-type shortening consumption in rats

When non-food-deprived rats are given intermittent access to certain substances, consumption of those substances is greater than when more frequent access is provided. The present study examined the effects of three different shortening access conditions on subsequent shortening intake in rats. Each of the three different shortening conditions lasted five weeks and was followed by a five-week period in which shortening access was limited by time (1 h of availability) on either an Intermittent (Monday, Wednesday, Friday) or Daily schedule of access. In Part 1, limiting the quantity of shortening provided during the 1-h period of availability attenuated subsequent 1-h shortening intake in the Intermittent access group, but had no statistically significant effect in the Daily access group. In Part 2, unrestricted availability of shortening (24 h/day-7 days/week) attenuated subsequent 1-h shortening intake in all groups. In Part 3, shortening non-availability for five weeks enhanced subsequent 1-h shortening intake in all groups. It was also shown that rats under an Intermittent, but not a Daily, schedule of access consumed as much shortening during a 1-h period of availability, as was consumed in 24 h when shortening availability was unrestricted. These results demonstrate that while intermittent access is necessary and sufficient to stimulate binge-type eating in rats, the behavioral history can modulate binge size.

How accurate are lockable orthotic knee braces? An objective gait analysis study

There has been an increasing use of orthotic knee braces in the management of knee injuries but, to our knowledge, there is no gait analysis study assessing the accuracy of these braces. Eight healthy male subjects were studied to determine the accuracy of immobilisation or splintage provided by a lockable orthotic knee brace using gait analysis. Six types of immobilisation were studied: locked at 0, 10, 20, 30 degrees and unlocked in an orthotic knee brace, and without a brace. The knee flexion angles measured using the kinematic instruments at 0 and 10 degrees were significantly greater than those set at the knee brace. The knee flexion angle measured using the unlocked knee brace was significantly greater than that measured in the absence of a brace. This study highlights inaccuracies in a knee brace at low knee flexion angles. The higher actual angles alter the biomechanics of the knee joint and result in greater forces across the knee joint and especially the extensor mechanism.

The relationship of the angle of immobilisation of the knee to the force applied to the extensor mechanism when partially weight-bearing

We describe the influence of the angle of immobilisation during partial weight-bearing on the forces across the extensor mechanism of the knee. Gait analysis was performed on eight healthy male subjects with the right knee in an orthotic brace locked at 0°, 10°, 20° and 30°, with the brace unlocked and also without a brace. The ground reaction force, the angle of the knee and the net external flexion movement about the knee were measured and the extensor mechanism force was calculated.

The results showed a direct non-linear relationship between the angle of knee flexion and the extensor mechanism force. When a brace was applied, the lowest forces occurred when the brace was locked at 0°. At 30° the forces approached the failure strength of some fixation devices. We recommend that for potentially unstable injuries of the extensor mechanism, when mobilising with partial weight-bearing, the knee should be flexed at no more than 10°.

Re-admission rates within 28 days of total hip replacement

INTRODUCTION

The aim of the study was to identify the reasons for the higher than expected emergency re-admission to hospital within 28 days of total hip replacement (THR) for Stepping Hill Hospital, Stockport.

PATIENTS AND METHODS

Over a 42-month period, 65 (8.5%) of 769 patients were re-admitted within 28 days of discharge following primary THR. Case notes for 61 patients were available for retrospective review to assess premorbidity, initial postoperative complications and reason for re-admission.

RESULTS

The main reasons for re-admission were complications related to the procedure. These included thrombo-embolic disease 2.5%, atraumatic dislocation 1.4%, wound complications 1.2% and swollen limb 1.8%. Other causes such as admission to another department for problems not related to THR accounted for 0.8%.

CONCLUSIONS

Our findings are comparable with the published literature for early complications following THR. The three main reasons for re-admission were atraumatic dislocation, thrombo-embolic and wound complications such as superficial infection and haematoma are the commonest world-wide. The re-admission rate to hospital within the first 28 days following THR was a clinical indicator suggested by the UK Department of Health. It has subsequently been incorporated in a group of indicators used by the CASPE Healthcare Knowledge Systems (CHKS), a private healthcare consultancy and analysis company, for peer benchmarking. Our re-admission rates are inflated by admissions for non-THR-related reasons. The level of post-THR complications leading to re-admission were acceptable compared with the available published literature regarding 28-day re-admission. We anticipate that this study may act as a benchmark for other trusts.

The role of preoperative templating in total knee arthroplasty: comparison of three prostheses

Templating of preoperative radiographs is routinely recommended prior to knee arthroplasty. We performed this study to assess the reproducibility and accuracy of the templates for three commonly used knee implants (PFC, Kinemax, Scorpio). Six lower limb surgeons templated 10 patients for each of the three designs. The inter- and intra-observer reliability and accuracy was calculated. There was marked variation in the reliability of the templating with the tibial insert scoring better than the femoral and the Kinemax being the most reproducible of the three. In general, the intra-observer scores (kappa=0.57-0.81) were better than the inter-observer ones (kappa=0.21-0.60). The Scorpio was the most accurately templated of the three implants, with the percentage correlating with what was actually implanted ranging from 55% to 62% for the femur and 72% to 75% for the tibia, with no templated sizes more than one size different from the actual implant. The other implants ranged from 38% to 42% for the femur and 53% to 58% for the tibia with both having up to 3% more than 1 size difference from the actual implant. We believe that the use of templating in total knee arthroplasty should be interpreted with caution and we urge the development of more accurate prosthesis sizing techniques.

Sporting and physical activity following Oxford medial unicompartmental knee arthroplasty

The purpose of this study was to evaluate and assess the sporting and physical activities of patients who had undergone an Oxford medial unicompartmental knee arthroplasty (UKA). Seventy-six patients who underwent a UKA between 2000 and 2003 were reviewed. Demographic data such as age, sex and comorbidities were recorded. University of California Los Angeles (UCLA) activity level ratings and Oxford knee scores were determined for each patient. The sporting and physical activities of all patients' pre- and post-operatively were recorded. The mean age of patients was 64 years (range 49-81) at surgery and 66 years (range 53-82) at review. The mean follow up time was 18 months (range 4-46). Following surgery there was a significant improvement in UCLA activity level scores from 4.2 to 6.5 (Wilcoxon Matched-pairs Signed-rank Test, p<0.01). Forty-two patients (64%) regularly participated in sport before they became symptomatic with significant knee pain, and thirty-nine patients (59%) regularly participated in sports after surgery. In total 93% of patients successfully returned to their regular sporting and physical activities following surgery. The published long-term survivorship of the Oxford UKA has given surgeons increasing confidence to use the prosthesis on a younger generation of patients. Our study has demonstrated that this population of patients is extremely active. A more detailed study is required to evaluate the long-term effects of sporting activity on the Oxford UKA.

The use of knee splints after total knee replacements

The aim of this randomised prospective study was to establish whether the use of knee splints following total knee replacement is necessary. The study included 81 patients undergoing total knee replacement who were randomised into a 'splint' and a 'no splint' group post-operatively. The following parameters were recorded: The range of movement pre-operatively, 5 days post-operatively and 6 weeks post-operatively; the length of time to straight leg raise; the blood drained from the wound; and the amount of post-operative analgesia required. We found that patients in the 'no splint' group achieved significantly greater flexion at 5 days and 6 weeks post-operatively but drained significantly more blood from the wound. Transfusion requirements were similar in the two groups. There was no other significant difference in the parameters measured between the two groups. In conclusion we found no evidence to advocate the use of knee splints following total knee arthroplasty.

Direct determination of particle-particle interactions in a 2D plasma dust crystal

Particle interactions were directly determined from the lateral compression of two-dimensional plasma dust crystals confined in a parabolic potential well. Measured particle separations combined with an equation of state for the crystal were used to derive values for the particle screening length and the charge on the particles. The shape of the parabolic potential well was confirmed by observing trajectories of single particles falling within the well. No evidence of a lateral particle-particle binding was observed.

Mucoepidermoid/adenosquamous carcinoma of the skin: presentation of two cases

BACKGROUND

Mucoepidermoid carcinoma is a relatively common neoplasm of the major and minor salivary glands comprising 10-30% of primary carcinomas. They may involve the skin through direct extension, metastases, and rarely, as a primary focus (adenosquamous carcinoma).

OBJECTIVE

To discuss through case reports, the nomenclature, histology, clinical course, and treatment of mucoepidermoid/adenosquamous carcinoma.

METHODS

We present a case of mucoepidermoid carcinoma primary to an upper eyelid accessory lacrimal gland with direct cutaneous extension and a case of primary cutaneous adenosquamous carcinoma of the scalp.

RESULTS

An eyelid neoplasm of lacrimal origin was initially treated with Mohs micrographic surgery (MMS), requiring an orbital exenteration to achieve a tumor-free plane. In the second case, a primary scalp lesion was cleared with MMS. Neither patient has had local recurrence or metastases.

CONCLUSION

Correct diagnosis is crucial to pursuing adequate treatment for this aggressive neoplasm. We support the use of MMS to achieve local control.

Outcome measurement in the ACL deficient knee--what's the score?

There is increasing pressure within the United Kingdom for transparent assessment of the performance of every doctor along with the procedures they perform. Unfortunately, the validation of the outcome measures used to assess such procedures has been questioned. This has been well illustrated in the anterior cruciate ligament (ACL) deficient knee. Over 54 different outcome measures used to assess the ACL deficient knee have been identified, few of which were formally assessed at their initial publication. For those most frequently used the Lysholm (I and II) knee scoring scale and Tegner activity score are the only ones to have been adequately validated prior to use. The Cincinnati rating system and International Knee Documentation Committee (IKDC) form were not assessed and the reliability of both measures has since been questioned. Appropriately tested newer measures include the IKDC subjective knee evaluation form, Mohtadi's ACL quality of life outcome measure and the Knee injury and osteoarthritis outcome score (KOOS). We recommend use of the Lysholm II knee scoring scale and Tegner activity score for clinical follow-up of patients and for use as a gold standard to which future measures can be compared. These have their deficiencies and will ultimately require replacement. In view of the international standing of its authors, the IKDC subjective knee evaluation form is likely to be used in preference to the KOOS despite its attractions. For long-term clinical trials the SF-36 should also be used. Further research is required to produce suitable measures for assessing the ACL deficient knee and this work should be appropriately funded.

Is tourniquet use necessary for knee arthroscopy?

PURPOSE

With several studies identifying the tourniquet as a factor for increased risk of complications in knee arthroscopy, we wished to identify whether its use is necessary.

TYPE OF STUDY

We performed a prospective randomized trial on 109 patients undergoing knee arthroscopy.

MATERIALS AND METHODS

All patients had a tourniquet placed on the thigh and were assigned to either have it inflated or not inflated. Personal information, operative details, postoperative pain scores, analgesic requirements, and complications were recorded.

RESULTS

The 2 groups were comparable. There was no significant difference between the 2 groups with respect to operative view, duration of operation, pain scores, analgesic requirements, or complications. The tourniquet required intraoperative inflation in 4 patients assigned not to have it inflated; in 1 patient, the tourniquet made no difference to the operative view.

CONCLUSIONS

Many orthopaedic units continue to use a tourniquet routinely for knee arthroscopy, probably in the belief that a clear operative view can only be achieved with one. However, the findings in our trial indicate that knee arthroscopy may be performed adequately without the use of a tourniquet. Therefore, we recommend that its routine use for this procedure is discontinued.

Closure of palatal fistula with a local mucoperiosteal flap lined with buccal mucosal graft

OBJECTIVE

Oro-nasal fistula is a common complication of palatoplasty. Current methods for fistula repair utilize mucoperiosteal flaps or pedicled flaps. These procedures are often cumbersome and leave a raw nasal surface, which may increase the incidence of postoperative risks and problems. In addition, the recurrence rate of the fistula is as high as 34%. We propose a simple two-layer method of fistula repair to avoid recurrences.

DESIGN

A standard mucoperiosteal flap is raised on the oral side. A buccal mucosal graft is harvested from the cheeks and sutured to the nasal side of the flap that is then inset into the fistula.

SETTING

Patients were either referred to the senior author's private practice (four patients) or were patients who had previously been operated on by the senior author himself (three patients).

SUBJECTS

Study subjects consisted of seven patients, four males and three females, ages 14 months to 8 years. All patients had previously undergone cleft palate repair, complicated by subsequent oro-nasal fistula formation.

INTERVENTIONS

All patients underwent oro-nasal fistula repair under general anesthesia with a local mucoperiosteal flap lined with buccal mucosal grafts placed on the nasal side of the flap.

RESULTS

In all cases, the fistula was completely closed at first attempt without complications. Patients were followed for a minimum of 2 years, without evidence of recurrence.

CONCLUSIONS

Our proposed surgical procedure for fistula closure using a standard mucoperiosteal flap lined with a buccal mucosal graft is a suitable alternative for the repair of postpalatoplasty oro-nasal fistulas. Further study and long-term follow-up is needed to establish this method as a new standard form of repair.

Current imaging and possible therapeutic management of glucagonoma tumors: a case report

Glucagonomas, like other neuroendocrine tumors, express somatostatin receptors in more than 80% of cases. Unfortunately, because of the rarity of these tumors, the sensitivity and specificity of somatostatin analog (octreotide) imaging have not been established. Nonetheless, there have been limited reports in the literature supporting the use of indium In-111 DTPA N-terminal D-phenylalanine (D-PHE1) octreotide for glucagonoma imaging and may be most beneficial as an adjuvant to conventional imaging for tumor staging and therapeutic decision making. Current therapeutic applications of octreotide focus on stabilization of disease in tumors expressing somatostatin receptors, and tumor destruction, using beta-emitting isotopes. In this report, imaging of a glucagonoma with In-111 DTPA-D-PHE1 octreotide scintigraphy is described in a 51-year-old woman examined for a large palpable abdominal mass.

Imaging of non-small-cell lung cancer with indium-111 pentetreotide

PURPOSE

Lung cancer is the leading cause of cancer deaths in the United States. Non-small-cell lung cancer (NSCLC) accounts for 75% to 85% of lung cancers. CT has been the standard anatomic study for localizing and staging NSCLC, although it is associated only with moderate accuracy. In-111 pentetreotide, a radiolabeled somatostatin analog largely used in the scintigraphic localization of neuroendocrine tumors, has been shown incidentally to identify NSCLC lesions. This observation is important in the workup for metastatic disease for neuroendocrine tumors, because presumed metastatic lesions may actually be second primary tumors of NSCLC. In-111 may also serve as a potentially useful adjunct to CT in the anatomic evaluation of NSCLC. The purpose of this study was to determine the likelihood of detecting and localizing NSCLC using In-111 pentetreotide scintigraphy.

MATERIALS AND METHODS

Ten patients with known or possible NSCLC were examined using In-111 pentetreotide. Scans were compared with the patients' previously performed chest radiographs and CT scans.

RESULTS

In-111 pentetreotide imaging correctly identified sites of tumor involvement as detected by chest CT and surgery in all 10 patients with NSCLC.

CONCLUSION

This study demonstrates the uptake of In-111 pentetreotide by NSCLC. This important observation should be considered in the workup for metastatic disease of neuroendocrine tumors with In-111 pentetreotide, because NSCLC can be a source of false-positive findings. In-111 pentetreotide imaging may also serve as a potentially useful adjunct to CT for identifying obscured or equivocal lesions and as an aid in localizing tissue for biopsy.

Common peroneal nerve palsy following knee arthroscopy

We report the case of a 43-year-old woman who underwent knee arthroscopy. Postoperatively, she developed a lesion of the common peroneal nerve, which was confirmed by neurophysiological studies. Exploration showed the nerve to be in continuity and externally undamaged. At review 17 months later, there was incomplete recovery. We believe this lesion was caused by a traction injury related to patient positioning, which has not been reported previously.

Catalytic enantioselective amination of enolsilanes using C2-symmetric copper(II) complexes as chiral Lewis acids

[formula: see text] [Cu(S,S)-t-Bu-box](OTf)2 (1) catalyzes the enantioselective amination of enolsilanes with azodicarboxylate derivatives. Isomerically pure enolsilanes of aryl ketones, acylpyrroles, and thioesters added to the azo-imide in greater than 95% ee. The use of an alcohol additive was critical to achieving catalyst turnover.

Oxymetazoline in the treatment of posterior epistaxis

In this retrospective study, 36 patients were given oxymetazoline as a first step in treatment for posterior epistaxis. In 75% of the cases, epistaxis was effectively treated with oxymetazoline with no recurrent bleeding. All cases with recurrence resolved with continued administration of oxymetazoline. The results of this study propose a pharmacologic intervention for the treatment of posterior epistaxis.

Advanced techniques in liposuction

Liposuction is a procedure that has been widely used since the 1980s. The introduction of the tumescent technique in 1987 greatly improved the safety of the procedure. Innovative techniques and equip ment modifications have continued to evolve, broadening the scope of application and improving the results that can be obtained. This article discusses several recent advancements in liposuction techniques. Three-Dimensional Tumescent Liposculpture (William R. Cook, Coronado, CA) was developed to view contiguous areas of the body as a unit rather than to simply suction fat from one particular area. Advanced techniques have improved the ability to liposuction difficult areas, such as the arms, calves, medial thighs, and the male breast. A combination of syringe-suction and machine-assisted liposculpture is sometimes used. Tumescent liposculpture has been combined with pulsed CO2 laser surgery to produce a more effective and less invasive treatment for the aging face, neck, and jowls. External ultrasound-assisted liposculpture can produce excellent results.

Community solutions to violence: a Minnesota managed care action plan

Reducing violence is a critical health and economic priority. In Minnesota, as in other parts of the United States, violence is increasingly viewed as a public health problem. Helping people work together to prevent violence is one way that managed care organizations are collaborating with public health to improve the health of communities. In 1994, Blue Cross and Blue Shield of Minnesota worked with community organizations to develop The Minnesota Action Plan to End Gun Violence, a broad-based solution to a community problem: violence in Minnesota. The goal of this initiative was to develop grassroots solutions to violence and to inspire community members to take action. Outcomes of the initiative included: participation by over 1,000 Minnesotans in 12 community violence prevention forums; a widely distributed action plan; Students Stop Guns, a school-based intervention to keep Minnesota schools gun-free; the Governor's Task Force on Violence as a Public Health Problem, which led to a commitment of resources to prevent violence and respond to the victims and consequences of violence, and the Health Care Coalition on Violence, to institutionalize strategies within the Minnesota health care environment. The project's qualitative evaluation resulted in lessons and advice on how to execute a collaborative health improvement initiative. These lessons have been widely shared with Minnesota community health advocates.

Orthopaedic referrals from a cardiothoracic transplant population

In this study we audited the orthopaedic referrals from the cardiothoracic transplant population at Wythenshawe Hospital, South Manchester. A total of 33 referrals in 29 patients were made during the period of study. The referrals represented 10.3% (33/321) of the transplant population. However, the rate of referral per postoperative year was 37.9/1000, which was of a similar order to that of the general population. The diagnosis at referral was activity related in 24 (72.7%) referrals, with one-half of these being related to some form of sporting activity. Complications of immunosuppression may have contributed in up to 15 (45.4%) of referrals. We believe that musculoskeletal problems after cardiothoracic transplantation do not place an excessive burden on our orthopaedic department and that the pattern of referrals indicates that the transplant programme is a success.

The hidden cost of audit

Although a considerable sum of money has been made available for the introduction of medical audit, many of the indirect costs have not been considered. We have assessed one of these areas, the medical audit meeting, by calculating the cost to Preston Acute Hospitals (PAH) Trust and extrapolating it to England and Wales. A potential cost of Pounds 678,000 per annum to PAH Trust could be reduced to 14 per cent of this figure if current practices were changed. The hidden cost for England and Wales could be up to Pounds 106 million per annum. The cost of medical audit meetings could be dramatically reduced if current practices were modified. This could be done with little detriment to the audit process.