Endocranial ontogeny and evolution in early Homo sapiens: The evidence from Herto, Ethiopia.

Fossils and artifacts from Herto, Ethiopia, include the most complete child and adult crania of early Homo sapiens. The endocranial cavities of the Herto individuals show that by 160,000 y ago, brain size, inferred from endocranial size, was similar to that seen in modern human populations. However, endocranial shape differed from ours. This gave rise to the hypothesis that the brain itself evolved substantially during the past ∼200,000 y, possibly in tandem with the transition from Middle to Upper Paleolithic techno-cultures. However, it remains unclear whether evolutionary changes in endocranial shape mostly reflect changes in brain morphology rather than changes related to interaction with maxillofacial morphology. To discriminate between these effects, we make use of the ontogenetic fact that brain growth nearly ceases by the time the first permanent molars fully erupt, but the face and cranial base continue to grow until adulthood. Here we use morphometric data derived from digitally restored immature and adult H. sapiens fossils from Herto, Qafzeh, and Skhul (HQS) to track endocranial development in early H. sapiens. Until the completion of brain growth, endocasts of HQS children were similar in shape to those of modern human children. The similarly shaped endocasts of fossil and modern children indicate that our brains did not evolve substantially over the past 200,000 y. Differences between the endocranial shapes of modern and fossil H. sapiens adults developed only with continuing facial and basicranial growth, possibly reflecting substantial differences in masticatory and/or respiratory function.

Estimating sexual size dimorphism in fossil species from posterior probability densities.

Accurate characterization of sexual dimorphism is crucial in evolutionary biology because of its significance in understanding present and past adaptations involving reproductive and resource use strategies of species. However, inferring dimorphism in fossil assemblages is difficult, particularly with relatively low dimorphism. Commonly used methods of estimating dimorphism levels in fossils include the mean method, the binomial dimorphism index, and the coefficient of variation method. These methods have been reported to overestimate low levels of dimorphism, which is problematic when investigating issues such as canine size dimorphism in primates and its relation to reproductive strategies. Here, we introduce the posterior density peak (pdPeak) method that utilizes the Bayesian inference to provide posterior probability densities of dimorphism levels and within-sex variance. The highest posterior density point is termed the pdPeak. We investigated performance of the pdPeak method and made comparisons with the above-mentioned conventional methods via 1) computer-generated samples simulating a range of conditions and 2) application to canine crown-diameter datasets of extant known-sex anthropoids. Results showed that the pdPeak method is capable of unbiased estimates in a broader range of dimorphism levels than the other methods and uniquely provides reliable interval estimates. Although attention is required to its underestimation tendency when some of the distributional assumptions are violated, we demonstrate that the pdPeak method enables a more accurate dimorphism estimate at lower dimorphism levels than previously possible, which is important to illuminating human evolution.

Canine sexual dimorphism in Ardipithecus ramidus was nearly human-like.

Body and canine size dimorphism in fossils inform sociobehavioral hypotheses on human evolution and have been of interest since Darwin's famous reflections on the subject. Here, we assemble a large dataset of fossil canines of the human clade, including all available Ardipithecus ramidus fossils recovered from the Middle Awash and Gona research areas in Ethiopia, and systematically examine canine dimorphism through evolutionary time. In particular, we apply a Bayesian probabilistic method that reduces bias when estimating weak and moderate levels of dimorphism. Our results show that Ar. ramidus canine dimorphism was significantly weaker than in the bonobo, the least dimorphic and behaviorally least aggressive among extant great apes. Average male-to-female size ratios of the canine in Ar. ramidus are estimated as 1.06 and 1.13 in the upper and lower canines, respectively, within modern human population ranges of variation. The slightly greater magnitude of canine size dimorphism in the lower than in the upper canines of Ar. ramidus appears to be shared with early Australopithecus, suggesting that male canine reduction was initially more advanced in the behaviorally important upper canine. The available fossil evidence suggests a drastic size reduction of the male canine prior to Ar. ramidus and the earliest known members of the human clade, with little change in canine dimorphism levels thereafter. This evolutionary pattern indicates a profound behavioral shift associated with comparatively weak levels of male aggression early in human evolution, a pattern that was subsequently shared by Australopithecus and Homo.

Integrative geochronology calibrates the Middle and Late Stone Ages of Ethiopia's Afar Rift.

The Halibee member of the Upper Dawaitoli Formation of Ethiopia's Middle Awash study area features a wealth of Middle and Later Stone Age (MSA and LSA) paleoanthropological resources in a succession of Pleistocene sediments. We introduce these artifacts and fossils, and determine their chronostratigraphic placement via a combination of established radioisotopic methods and a recently developed dating method applied to ostrich eggshell (OES). We apply the recently developed 230Th/U burial dating of OES to bridge the temporal gap between radiocarbon (14C) and 40Ar/39Ar ages for the MSA and provide 14C ages to constrain the younger LSA archaeology and fauna to ∼24 to 21.4 ka. Paired 14C and 230Th/U burial ages of OES agree at ∼31 ka for an older LSA locality, validating the newer method, and in turn supporting its application to stratigraphically underlying MSA occurrences previously constrained only by a maximum 40Ar/39Ar age. Associated fauna, flora, and Homo sapiens fossils are thereby now fixed between 106 ± 20 ka and 96.4 ± 1.6 ka (all errors 2σ). Additional 40Ar/39 results on an underlying tuff refine its age to 158.1 ± 11.0 ka, providing a more precise minimum age for MSA lithic artifacts, fauna, and H. sapiens fossils recovered ∼9 m below it. These results demonstrate how chronological control can be obtained in tectonically active and stratigraphically complex settings to precisely calibrate crucial evidence of technological, environmental, and evolutionary changes during the African Middle and Late Pleistocene.

A powder XRD, solid state NMR and calorimetric study of the phase evolution in mechanochemically synthesized dual cation (Csx(CH3NH3)1-x)PbX3 lead halide perovskite systems.

Methylammonium (MA+) lead halide perovskites (MAPbX3) have been widely investigated for photovoltaic applications, with the addition of Cs improving structural and thermal stability. This study reports the complete A site miscibility of Cs+ and MA+ cations in the lead chloride and lead bromide perovskites with nominal stoichiometric formulae (CsxMA1-x)Pb(Cl/Br)3 (x = 0, 0.13, 0.25, 0.37, 0.50, 0.63, 0.75, 0.87, 1). These suites of materials were synthesized mechanochemically as a simple, cost-effective synthesis technique to produce highly ordered, single phase particles. In contrast to previous studies using conventional synthetic routes that have reported significant solubility gaps, this solvent-free approach induces complete miscibility within the dual cation Cs+/MA+ system, with the resultant structures exhibiting high short-range and long-range atomic ordering across the entire compositional range that are devoid of solvent inclusions and disorder. The subtle structural evolution from cubic to orthorhombic symmetry reflecting PbX6 octahedral tilting was studied using complementary high resolution TEM, powder XRD, multinuclear 133Cs/207Pb/1H MAS NMR, DSC, XPS and UV/vis approaches. The phase purity and exceptional structural order were reflected in the very high resolution HRTEM images presented from particles with crystallite sizes in the ∼80-170 nm range, and the stability and long lifetimes of the Br series (10-20 min) and the Cl series (∼30 s-1 min) under the 200 kV/146 µA e- beam. Rietveld refinements associated with the room temperature PXRD study demonstrated that each system converged towards single phase compositions that were very close to the intended target stoichiometries, thus indicating the complete miscibility within these dual cation Cs+/MA+ solid solution systems. The multinuclear MAS NMR data showed a distinct sensitivity to the changing solid solution compositions across the MAPbX3-CsPbX3 partition. In particular, the 133Cs shifts demonstrated a sensitivity to the cubic-orthorhombic phase transition while the 133Cs T1s exhibited a pronounced sensitivity to the variable Cs+ cation mobility across the compositional range. Variable temperature PXRD studies facilitated the production of phase diagrams mapping the Cs+/MA+ compositional space for the (CsxMA1-x)PbCl3 and (CsxMA1-x)PbBr3 solid solution series, while Tauc plots of the UV/vis data exhibited reducing bandgaps with increasing MA+ incorporation through ranges of cubic phases where octahedral tilting was absent.

IMPACT-Global Hip Fracture Audit: Nosocomial infection, risk prediction and prognostication, minimum reporting standards and global collaborative audit: Lessons from an international multicentre study of 7,090 patients conducted in 14 nations during the COVID-19 pandemic.

AIMS: This international study aimed to assess: 1) the prevalence of preoperative and postoperative COVID-19 among patients with hip fracture, 2) the effect on 30-day mortality, and 3) clinical factors associated with the infection and with mortality in COVID-19-positive patients. METHODS: A multicentre collaboration among 112 centres in 14 countries collected data on all patients presenting with a hip fracture between 1st March-31st May 2020. Demographics, residence, place of injury, presentation blood tests, Nottingham Hip Fracture Score, time to surgery, management, ASA grade, length of stay, COVID-19 and 30-day mortality status were recorded. RESULTS: A total of 7090 patients were included, with a mean age of 82.2 (range 50-104) years and 4959 (69.9%) being female. Of 651 (9.2%) patients diagnosed with COVID-19, 225 (34.6%) were positive at presentation and 426 (65.4%) were positive postoperatively. Positive COVID-19 status was independently associated with male sex (odds ratio (OR) 1.38, p = 0.001), residential care (OR 2.15, p < 0.001), inpatient fall (OR 2.23, p = 0.003), cancer (OR 0.63, p = 0.009), ASA grades 4 (OR 1.59, p = 0.008) or 5 (OR 8.28, p < 0.001), and longer admission (OR 1.06 for each increasing day, p < 0.001). Patients with COVID-19 at any time had a significantly lower chance of 30-day survival versus those without COVID-19 (72.7% versus 92.6%, p < 0.001). COVID-19 was independently associated with an increased 30-day mortality risk (hazard ratio (HR) 2.83, p < 0.001). Increasing age (HR 1.03, p = 0.028), male sex (HR 2.35, p < 0.001), renal disease (HR 1.53, p = 0.017), and pulmonary disease (HR 1.45, p = 0.039) were independently associated with a higher 30-day mortality risk in patients with COVID-19 when adjusting for confounders. CONCLUSION: The prevalence of COVID-19 in hip fracture patients during the first wave of the pandemic was 9%, and was independently associated with a three-fold increased 30-day mortality risk. Among COVID-19-positive patients, those who were older, male, with renal or pulmonary disease had a significantly higher 30-day mortality risk.

Human bony labyrinth is an indicator of population history and dispersal from Africa.

The dispersal of modern humans from Africa is now well documented with genetic data that track population history, as well as gene flow between populations. Phenetic skeletal data, such as cranial and pelvic morphologies, also exhibit a dispersal-from-Africa signal, which, however, tends to be blurred by the effects of local adaptation and in vivo phenotypic plasticity, and that is often deteriorated by postmortem damage to skeletal remains. These complexities raise the question of which skeletal structures most effectively track neutral population history. The cavity system of the inner ear (the so-called bony labyrinth) is a good candidate structure for such analyses. It is already fully formed by birth, which minimizes postnatal phenotypic plasticity, and it is generally well preserved in archaeological samples. Here we use morphometric data of the bony labyrinth to show that it is a surprisingly good marker of the global dispersal of modern humans from Africa. Labyrinthine morphology tracks genetic distances and geography in accordance with an isolation-by-distance model with dispersal from Africa. Our data further indicate that the neutral-like pattern of variation is compatible with stabilizing selection on labyrinth morphology. Given the increasingly important role of the petrous bone for ancient DNA recovery from archaeological specimens, we encourage researchers to acquire 3D morphological data of the inner ear structures before any invasive sampling. Such data will constitute an important archive of phenotypic variation in present and past populations, and will permit individual-based genotype-phenotype comparisons.

Systematic review of randomised controlled trials for interventions to treat injuries to the medial ligaments of the knee.

BACKGROUND: Optimal management of severe and complex injuries to the medial knee ligaments remains uncertain. This systematic review evaluates outcomes from randomised controlled trials investigating interventions for treating injuries of medial ligaments of the knee. METHODS: Randomised controlled clinical trials evaluating interventions for treating injuries of the medial knee ligaments were identified through searching EMBASE, Medline, Cochrane, WHO, and clinicaltrials.org. Comparisons were made between different non-operative interventions, surgical versus non-operative interventions, different surgical interventions, and different postoperative interventions. Primary outcome measures included patient reported outcome measures (PROM) of knee function, pain, and treatment failure. RESULTS: 412 trial records were identified; 259 were non-redundant and distinct studies, of which eight were included for analysis. No differences between operative and non-operative management strategies were found for either primary outcome: Lysholm and IKDC scores. Compared to non-operative interventions, operative interventions resulted in reduced quadriceps strength at eight weeks (mean difference (MD) 29 (% knee extension strength deficit compared with unaffected knee); 95%CI 3.89-54.11) and were associated with greater incidence of minor complications (relative risk (RR) 25; 95%CI: 1.51-421, and RR 25; 95%CI: 1.50-416.58, respectively). Quadriceps strength between 16 and 52 weeks was similar in non-operative and operative groups (MD 20; 95%CI -1.92-41.92). Functional rehabilitation was associated with reduced valgus laxity at six weeks compared to bracing ((MD) -1.40; 95%CI: -2.21-0.59). CONCLUSIONS: Non-operative interventions provided similar functional results to operative interventions for grade I-III injuries of the medial collateral ligaments. Non-operative intervention was associated with improved quadriceps strength during rehabilitation, and fewer complications, compared to operative interventions.

Hominid butchers and biting crocodiles in the African Plio-Pleistocene.

Zooarchaeologists have long relied on linear traces and pits found on the surfaces of ancient bones to infer ancient hominid behaviors such as slicing, chopping, and percussive actions during butchery of mammal carcasses. However, such claims about Plio-Pleistocene hominids rely mostly on very small assemblages of bony remains. Furthermore, recent experiments on trampling animals and biting crocodiles have shown each to be capable of producing mimics of such marks. This equifinality-the creation of similar products by different processes-makes deciphering early archaeological bone assemblages difficult. Bone modifications among Ethiopian Plio-Pleistocene hominid and faunal remains at Asa Issie, Maka, Hadar, and Bouri were reassessed in light of these findings. The results show that crocodiles were important modifiers of these bone assemblages. The relative roles of hominids, mammalian carnivores, and crocodiles in the formation of Oldowan zooarchaeological assemblages will only be accurately revealed by better bounding equifinality. Critical analysis within a consilience-based approach is identified as the pathway forward. More experimental studies and increased archaeological fieldwork aimed at generating adequate samples are now required.

Research questions to facilitate the future development of European long-term ecosystem research infrastructures: A horizon scanning exercise.

Distributed environmental research infrastructures are important to support assessments of the effects of global change on landscapes, ecosystems and society. These infrastructures need to provide continuity to address long-term change, yet be flexible enough to respond to rapid societal and technological developments that modify research priorities. We used a horizon scanning exercise to identify and prioritize emerging research questions for the future development of ecosystem and socio-ecological research infrastructures in Europe. Twenty research questions covered topics related to (i) ecosystem structures and processes, (ii) the impacts of anthropogenic drivers on ecosystems, (iii) ecosystem services and socio-ecological systems and (iv), methods and research infrastructures. Several key priorities for the development of research infrastructures emerged. Addressing complex environmental issues requires the adoption of a whole-system approach, achieved through integration of biotic, abiotic and socio-economic measurements. Interoperability among different research infrastructures needs to be improved by developing standard measurements, harmonizing methods, and establishing capacities and tools for data integration, processing, storage and analysis. Future research infrastructures should support a range of methodological approaches including observation, experiments and modelling. They should also have flexibility to respond to new requirements, for example by adjusting the spatio-temporal design of measurements. When new methods are introduced, compatibility with important long-term data series must be ensured. Finally, indicators, tools, and transdisciplinary approaches to identify, quantify and value ecosystem services across spatial scales and domains need to be advanced.

Crystal Chemistry of Vanadium-Bearing Ellestadite Waste Forms.

Vanadate ellestadites Ca10(SiO4) x(VO4)6-2 x(SO4) xCl2, serving as prototype crystalline matrices for the fixation of pentavalent toxic metals (V, Cr, As), were synthesized and characterized by powder X-ray and neutron diffraction (PXRD and PND), electron probe microanalysis (EPMA), Fourier transform infrared spectroscopy (FTIR), and solid-state nuclear magnetic resonance (SS-NMR). The ellestadites 0.19 < x < 3 adopt the P63/ m structure, while the vanadate endmember Ca10(VO4)6Cl2 is triclinic with space group P1̅. A miscibility gap exists for 0.77 < x < 2.44. The deficiency of Cl in the structure leads to short-range disorder in the tunnel. Toxicity characteristic leaching testing (TCLP) showed the incorporation of vanadium increases ellestadite solubility, and defined a waste loading limit that should not exceed 25 atom % V to ensure small release levels.

Neither chimpanzee nor human, Ardipithecus reveals the surprising ancestry of both.

Australopithecus fossils were regularly interpreted during the late 20th century in a framework that used living African apes, especially chimpanzees, as proxies for the immediate ancestors of the human clade. Such projection is now largely nullified by the discovery of Ardipithecus. In the context of accumulating evidence from genetics, developmental biology, anatomy, ecology, biogeography, and geology, Ardipithecus alters perspectives on how our earliest hominid ancestors--and our closest living relatives--evolved.

Ardipithecus ramidus and the evolution of the human cranial base.

The early Pliocene African hominoid Ardipithecus ramidus was diagnosed as a having a unique phylogenetic relationship with the Australopithecus + Homo clade based on nonhoning canine teeth, a foreshortened cranial base, and postcranial characters related to facultative bipedality. However, pedal and pelvic traits indicating substantial arboreality have raised arguments that this taxon may instead be an example of parallel evolution of human-like traits among apes around the time of the chimpanzee-human split. Here we investigated the basicranial morphology of Ar. ramidus for additional clues to its phylogenetic position with reference to African apes, humans, and Australopithecus. Besides a relatively anterior foramen magnum, humans differ from apes in the lateral shift of the carotid foramina, mediolateral abbreviation of the lateral tympanic, and a shortened, trapezoidal basioccipital element. These traits reflect a relative broadening of the central basicranium, a derived condition associated with changes in tympanic shape and the extent of its contact with the petrous. Ar. ramidus shares with Australopithecus each of these human-like modifications. We used the preserved morphology of ARA-VP 1/500 to estimate the missing basicranial length, drawing on consistent proportional relationships in apes and humans. Ar. ramidus is confirmed to have a relatively short basicranium, as in Australopithecus and Homo. Reorganization of the central cranial base is among the earliest morphological markers of the Ardipithecus + Australopithecus + Homo clade.

Structure and Thermal Expansion of Calcium-Thorium Apatite, [Ca4]F[Ca2Th4]T[(SiO4)6]O2.

Thorium silicate apatite with the formula [Ca3.84Th0.16]F[Ca2.79Th3.21]T(SiO4)6O2 · x(H) was synthesized by solid-state reaction, and its structure refined in P63/m from powder X-ray diffraction (XRD) data using the Rietveld method (a = 9.50172(9) Å, c = 6.98302(8) Å, V = 545.98(1) Å(3); R-Bragg = 2.102%). It was found that thorium partitions strongly to the tunnel (T) 6h position rather than the framework (F) 4f site. Fourier transform infrared spectroscopy revealed only SiO4 tetrahedron, with SiO5 and SiO6 groups, sometimes observed in siliceous apatites absent, at least to the limit of detection of this technique. Thermal expansion of the thorium apatite determined by high-temperature XRD from 298-1173 K found Δa (0.87%) dilation to exceed Δc (0.73%) with increasing temperature consistent with other silicate apatites.

Hydrothermal synthesis, structure investigation, and oxide ion conductivity of mixed Si/Ge-based apatite-type phases.

Apatite-type oxides ([A(I)4][A(II)6][(BO4)6]O2), particularly those of the rare-earth silicate and germanate systems, are among the more promising materials being considered as alternative solid oxide fuel cell electrolytes. Nonstoichiometric lanthanum silicate and germanate apatites display pure ionic conductivities exceeding those of yttria-stabilized zirconia at moderate temperatures (500-700 °C). In this study, mixed Si/Ge-based apatites were prepared by hydrothermal synthesis under mild conditions rather than the conventional solid-state method at high temperatures. Single-phase and highly crystalline nanosized apatite powders were obtained with the morphology changing across the series from spheres for the Si-based end member to hexagonal rods for the Ge-based end member. Powder X-ray and neutron analysis found all of these apatites to be hexagonal (P63/m). Quantitative X-ray microanalysis established the partial (<15 at%) substitution of La(3+) by Na(+) (introduced from the NaOH hydrothermal reagent), which showed a slight preference to enter the A(I) 4f framework position over the A(II) 6h tunnel site. Moreover, retention of hydroxide (OH(-)) was confirmed by IR spectroscopy and thermogravimetric analysis, and these apatites are best described as oxyhydroxyapatites. To prepare dense pellets for conductivity measurements, both conventional heat treatment and spark plasma sintering methods were compared, with the peculiar features of hydrothermally synthesized apatites and the influence of sodium on the ionic conductivity considered.

Structural study of the apatite Nd8Sr2Si6O26 by Laue neutron diffraction and single-crystal Raman spectroscopy.

A single-crystal structure determination of Nd8Sr2Si6O26 apatite, a prototype intermediate-temperature electrolyte for solid oxide fuel cells grown by the floating-zone method, was completed using the combination of Laue neutron diffraction and Raman spectroscopy. While neutron diffraction was in good agreement with P63/m symmetry, the possibility of P63 could not be convincingly excluded. This ambiguity was removed by the collection of orientation-dependent Raman spectra that could only be consistent with P63/m. The composition of Nd8Sr2Si6O26 was independently verified by powder X-ray diffraction in combination with electron probe microanalysis, with the latter confirming a homogeneous distribution of Sr and the absence of chemical zonation commonly observed in apatites. This comprehensive crystallochemical description of Nd8Sr2Si6O26 provides a baseline to quantify the efficacy of cation vacancies, oxygen superstoichiometry, and symmetry modification for promoting oxygen-ion mobility.

Delimitating species in paleoanthropology.

Evolutionary biologists created a large twentieth-century literature about delimiting biological species. Paleontologists contributed the unique complications of deep time. Toward century's end, one participant wrote: "In all probability more paper has been consumed on the questions of the nature and definition of the species than any other subject in evolutionary and systematic biology."

Impact of a keto diet on symptoms of Parkinson's disease, biomarkers, depression, anxiety and quality of life: a longitudinal study.

Aim: Evidence suggests low-carbohydrate diets (LCHF) may assist in treating neurodegenerative diseases such as Parkinson's disease (PD); however, gaps exist in the literature. Patients & methods: We conducted a small 24-week pilot study to investigate the effects of an LCHF diet on motor and nonmotor symptoms, health biomarkers, anxiety, and depression in seven people with PD. We also captured patient experiences during the process (quality of life [QoL]). Results: Participants reported improved biomarkers, enhanced cognition, mood, motor and nonmotor symptoms, and reduced pain and anxiety. Participants felt improvements enhanced their QoL. Conclusion: We conclude that an LCHF intervention is safe, feasible, and potentially effective in mitigating the symptoms of this disorder. However, more extensive randomized controlled studies are needed to create generalizable recommendations.

[Box: see text].

A national multicentre study of outcomes and patient satisfaction with the virtual fracture clinic and the influence of the COVID-19 pandemic: The MAVCOV study.

BACKGROUND: Virtual fracture clinics (VFCs) are advocated by the British Orthopaedic Association Standards for Trauma (BOAST). We aimed to assess the impact of the transition from face-to-face fracture clinic review and identify any change in clinical outcome and patient satisfaction. METHODS: A national, cross-sectional cohort study of VFCs across the UK over two separate two-week periods pre- and during the first UK COVID-19 lockdown was undertaken. Data comprising patient and injury characteristics, unplanned reattendance and complications within three months following discharge from VFC were collected by local collaborators. Telephone questionnaires were conducted to determine patient satisfaction and patient-reported outcome for patients discharged without face-to-face consultation. The primary outcome measure was the percentage of unplanned reattendances after direct discharge from VFC. RESULTS: Data was analysed for 51 UK VFCs comprising 6134 patients from the pre-pandemic group (06/05/2019-19/05/2019) and 4366 patients from the first UK lockdown (04/05/2020-17/05/2020). During lockdown, the rate of direct discharge from VFC increased significantly (odds ratio (OR) 2.01, p<0.001) from 30 % (n = 1856/6134) to 46 % (n = 2021/4366). The rate of compliance with BOAST guidance recommending fracture clinic review within three days increased (OR 1.93, p<0.001) from 82 % (n = 5003/6134) to 89 % (n = 3883/4366). There were no differences in the rates of unplanned reattendance (6 % pre- and 7 % during lockdown, p = 0.281) or complications (0.2 % for both, p = 0.815). There were 1527/3877 patients discharged without face-to-face review from VFC who completed telephone questionnaires (mean follow-up 18-months in pre-pandemic group and 6-months in lockdown group). Satisfaction was high in both cohorts (80 % pre- and 76 % lockdown, p = 0.093). Dissatisfaction was associated with an unplanned reattendance (p<0.001) or a missed injury (p<0.05). CONCLUSION: Despite a significant rise in direct discharge from VFC, there was no significant change in unplanned attendances, complications, or patient satisfaction. However, there are factors associated with dissatisfaction and these should be considered in the evolution of VFC.

Pre-existing knee osteoarthritis and severe joint depression are associated with the need for total knee arthroplasty after tibial plateau fracture in patients aged over 60 years.

Aims: This study aims to determine the rate of and risk factors for total knee arthroplasty (TKA) after operative management of tibial plateau fractures (TPFs) in older adults. Methods: This is a retrospective cohort study of 182 displaced TPFs in 180 patients aged ≥ 60 years, over a 12-year period with a minimum follow-up of one year. The mean age was 70.7 years (SD 7.7; 60 to 89), and 139/180 patients (77.2%) were female. Radiological assessment consisted of fracture classification; pre-existing knee osteoarthritis (OA); reduction quality; loss of reduction; and post-traumatic OA. Fracture depression was measured on CT, and the volume of defect estimated as half an oblate spheroid. Operative management, complications, reoperations, and mortality were recorded. Results: Nearly half of the fractures were Schatzker II AO B3.1 fractures (n = 85; 47%). Radiological knee OA was present at fracture in 59/182 TPFs (32.6%). Primary management was fixation in 174 (95.6%) and acute TKA in eight (4.4%). A total of 13 patients underwent late TKA (7.5%), most often within two years. By five years, 21/182 12% (95% confidence interval (CI) 6.0 to 16.7) had required TKA. Larger volume defects of greater depth on CT (median 15.9 mm vs 9.4 mm; p < 0.001) were significantly associated with TKA requirement. CT-measured joint depression of > 12.8 mm was associated with TKA requirement (area under the curve (AUC) 0.766; p = 0.001). Severe joint depression of > 15.5 mm (hazard ratio (HR) 6.15 (95% CI 2.60 to 14.55); p < 0.001) and pre-existing knee OA (HR 2.70 (95% CI 1.14 to 6.37); p = 0.024) were independently associated with TKA requirement. Where patients with severe joint depression of > 15.5 mm were managed with fixation, 11/25 ultimately required TKA. Conclusion: Overall, 12% of patients aged ≥ 60 years underwent TKA within five years of TPF. Severe joint depression and pre-existing knee arthritis were independent risk factors for both post-traumatic OA and TKA. These features should be investigated as potential indications for acute TKA in older adults with TPFs.