Search

Unlabelled: Computer-assisted technology creates a new approach to total knee arthroplasty (TKA). The primary purpose of this technology is to improve component placement and soft tissue balance. We asked whether the use of navigation techniques would lead to a narrow range of implant alignment in both coronal and sagittal planes and throughout the flexion-extension range. Using a prospective consecutive series of 57 navigated TKAs, we assessed intraoperative knee measurements, including alignment, varus-valgus stress angles in extension, and varus-valgus angles from 0 degrees to 90 degrees of flexion comparing postimplant with preimplant. We found fewer outliers with coronal (100% of TKAs within +/-2 degrees) and sagittal (0% of TKAs with fixed flexion greater than 5 degrees) alignment, soft tissue balancing (mean varus and valgus stress angles -3.2 degrees and 2.3 degrees; range, -5 degrees to 5 degrees), and mean femorotibial angle over flexion range 0 degrees (-0.2 degrees; range, -1 degrees to 2 degrees), 30 degrees (-0.2 degrees; range, -5 degrees to 4 degrees), 60 degrees (-0.5 degrees; range, -5 degrees to 7 degrees), and 90 degrees (-0.2 degrees; range, -5 degrees to 10 degrees). This technology allows a narrow range of implant placement and soft tissue management in extension. We anticipate improved ultimate patient outcomes with less tissue disruption. Level Of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Background: With 100,000 total knee arthroplasty (TKA) procedures taking place in the United Kingdom annually, the demand on rehabilitation services is high. Most regimes are home-based. Without clinician-patient interaction, detection of rehabilitation concerns can be delayed, reducing the chance of successful early intervention. Wearable technologies, such as MotionSense TM (Stryker, US), may offer a solution to this problem by remotely supporting post-operative TKA rehabilitation through the provision of personalised rehabilitation and tracking of home exercises, enabling healthcare professionals to continuously monitor rehabilitation progress remotely. Validation of such devices against a known kinematic model in activities of daily living is important for confident interpretation of resulting clinical data. The aim of this study therefore was to validate the accuracy of MotionSense TM against a clinical motion capture standard., Methods: Twenty younger and 14 older healthy, able-bodied adults attended one testing session (Younger: 24 ± 4 years old; Older: 71 ± 5 years old). Movement was tracked using Vicon motion analysis and a Plug-In-Gait lower body model was applied to all participants. Three activities were performed - walking, stair ascent, stair descent. The knee flexion angle root mean square error (RMSE) between the technologies was determined., Results: For both groups the knee flexion RMSE remained below 3° for all activities. The combined RMSE for all adults was 2.4° for walking, 2.7° for stair ascent, and 2.6° for stair descent. The signed error increased during the swing phase of gait., Conclusion: MotionSense TM was found to accurately estimate knee flexion angles during several common activities compared to Vicon motion capture., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: The aim was to review the literature regarding needle arthroscopy using the Arthrex NanoScope system and evaluate: (1) the diagnostic indications, utility, and efficacy compared to conventional methods, and (2) the therapeutic indications, safety, and reported outcomes., Methods: Searches of three databases (MEDLINE, Embase and PubMed) were conducted in November 2021 using MeSH terms: 'needle arthroscopy', 'human', 'in office arthroscopy', 'needle arthroscope', 'nanoscopic', 'surgery', 'nanoscope' and 'percutaneous arthroscopy'. The included studies were catalogued, quality-assessed using Methodological Index for Non-Randomised Studies (MINORS), and analysed using the Cochrane data collection templates for randomised control trials (RCT) and non-randomised control trials (non-RCT). The majority of studies were non-numerical and were examined using qualitative analysis., Results: The search yielded 314 studies, 22 of which were included for analysis. MINORS assessment was applicable to four studies. Mean MINORS was 10.7/16 with the most frequent limitations being lack of unbiased endpoint or sample size calculation. The level of evidence ranged from level IV-V. Diagnostic and therapeutic indications were described in relation to the: knee (n = 10); shoulder (n = 6); foot/ankle (n = 3); elbow (n = 2), and miscellaneous (n = 1)., Conclusions: Needle arthroscopy can augment the diagnostic process in patients presenting with musculoskeletal complaints, and may provide benefits in terms of diagnostic accuracy, cost efficiency, timeliness of investigation, and a visually impactful patient-centred consultation. Therapeutic interventions are reported by a small number of pioneer groups who report some benefits over conventional arthroscopy. The available literature remains small and of low quality, and more evidence is needed with regards to patient selection, efficacy, safety, and cost., Level of Evidence: Level V (based on the weakest study included in the Systematic Review)., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: Needle arthroscopy (NA) is an emerging technique that could streamline pathways, facilitate timely care, and reduce service burden. The primary aim was to assess the practical and economic viability of an outpatient NA service. Secondary aims were to assess the relative costs and benefits compared to a conventional arthroscopy (CA) service., Methods: This service feasibility study was conducted between 2021-2022 in a high-volume national treatment centre. A NA pathway was established for patients with chronic soft tissue pathology or early degenerative knee disease. The pathway was evaluated in terms of: i) cost; ii) efficiency, and iii) waste production, and an assessment was conducted of the patient-related and service-related effects., Results: The cost of the NA pathway was £1555.20 per patient, compared to £2,351.53 for CA. Time to management was 45 days for NA versus 180 days for CA. The NA pathway involved two hospital attendances, whereas CA required a minimum of three. NA cases produced 1.4 kg of non-recyclable waste compared to 5.0 kg produced by CA. For every two cases managed by NA instead of CA, capacity for one additional obligate-inpatient procedure was created., Conclusions: The NA pathway offers a technically and economically viable approach for the management of refractory knee symptoms in the context of chronic soft tissue or early degenerative disease. NA placed less demand on hospital resources, produced two-thirds less non-recyclable waste, and is amenable to a one-stop clinic approach. Clinical studies focused on objective and patient-reported outcome measures are required to assess clinical efficacy., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

Aims: The aim of this study was to assess factors associated with the estimated lifetime risk of revision surgery after primary knee arthroplasty (KA)., Methods: All patients from the Scottish Arthroplasty Project dataset undergoing primary KA during the period 1 January 1998 to 31 December 2019 were included. The cumulative incidence function for revision and death was calculated up to 20 years. Adjusted analyses used cause-specific Cox regression modelling to determine the influence of patient factors. The lifetime risk was calculated as a percentage for patients aged between 45 and 99 years using multiple-decrement life table methodology., Results: The estimated lifetime risk of revision ranged between 32.7% (95% confidence interval (CI) 22.6 to 47.3) for patients aged 45 to 49 years and 0.6% (95% CI 0.1 to 4.5) for patients aged over 90 years. At 20 years, the overall cumulative incidence of revision (6.8% (95% CI 6.6 to 7.0)) was significantly less than that of death (66.3% (95% CI 65.4 to 67.1)). Adjusted analyses demonstrated converse effect of increasing age on risk of revision (hazard ratio (HR) 0.5 (95% CI 0.5 to 0.6)) and death (HR 3.6 (95% CI 3.4 to 3.7)). Male sex was associated with increased risks of revision (HR 1.1 (95% CI 1.1 to 1.2); p < 0.001) and death (HR 1.4 (95% CI 1.3 to 1.4); p < 0.001). Compared to patients undergoing primary KA for osteoarthritis, patients with inflammatory arthropathy had a higher risk of death (HR 1.7 (95% CI 1.7 to 1.8); p < 0.001), but were less likely to be revised (HR 0.9 (95% CI 0.7 to 1.0); p < 0.001). Patients with a greater number of comorbidities (HR 1.4 (95% CI 1.3 to 1.4)) and greater levels of socioeconomic deprivation (HR 1.4 (95% CI 1.4 to 1.5)) were at increased risk of death, but neither increased the risk of revision., Conclusion: The estimated lifetime risk of revision KA varied depending on patient sex, age, and underlying diagnosis. Patients aged between 45 and 49 years had a one in three risk of undergoing revision surgery within their lifetime, which decreased with age to one in 159 in those aged 90 years or more.Cite this article: Bone Joint J  2022;104-B(12):1313-1322.

Background: Little evidence supports acquisition of routine head imaging after uncomplicated elective neurosurgical procedures for patients with unchanged neurological examinations; however, imaging is still performed by some neurointerventionalists. We assessed the clinical utility of routine computed tomography of the head (CTH) following elective neuroendovascular interventions, including aneurysm coiling, aneurysm stent-assisted coiling, aneurysm flow diversion, arteriovenous malformation/fistula embolization, middle meningeal artery embolization for subdural hematoma, extracranial carotid artery stenting, and venous sinus stenting., Methods: Retrospective chart review identified patients undergoing neuroendovascular intervention from 2011 to 2021 at our institution. Demographic, clinical, and radiographic variables, including presenting signs and symptoms, antiplatelets and/or anticoagulant medications, intraprocedural complications, postprocedural CTH findings, and postprocedural neurological examinations, were recorded. Association of clinical variables with an abnormal postprocedural CTH was assessed with univariate analysis. Patients with ruptured vascular pathology, preoperative embolizations, and missing postprocedural CTH images and/or reports were excluded., Results: Of 509 procedures identified, 354 were eligible for analysis; 4.8% of patients (17/354) had abnormal findings on postprocedural CTH. Nine patients had intraprocedural complications or new postprocedural neurological deficits that would have prompted imaging regardless of institutional practice. None of the remaining 8 (2.3%) patients required additional procedures. New postprocedural neurological deficit was the only significant predictor of abnormal postprocedural CTH (odds ratio = 6.79; 95% confidence interval, 2.01-20.32; P = 0.0009)., Conclusions: In a large cohort of patients undergoing elective neuroendovascular intervention, no patients were identified for whom routine postprocedural CTH alone meaningfully altered their clinical care. Routine CTH is not necessary after uncomplicated elective neuroendovascular interventions performed with careful postprocedural neurological assessment., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Functional connectivity (FC) is a sensitive metric that provides a readout of whole cortex coordinate neural activity in a mouse model. We examine the impact of experimental SAH modeled through endovascular perforation, and the effectiveness of subsequent treatment on FC, through three key questions: 1) Does the endovascular perforation model of SAH induce deficits in FC; 2) Does exposure to hypoxic conditioning provide protection against these FC deficits and, if so, is this neurovascular protection SIRT1-mediated; and 3) does treatment with the SIRT1 activator resveratrol alone provide protection against these FC deficits? Cranial windows were adhered on skull-intact mice that were then subjected to either sham or SAH surgery and either left untreated or treated with hypoxic post-conditioning (with or without EX527) or resveratrol for 3 days. Mice were imaged 3 days post-SAH/sham surgery, temporally aligned with the onset of major SAH sequela in mice. Here we show that the endovascular perforation model of SAH induces global and network-specific deficits in FC by day 3, corresponding with the time frame of DCI in mice. Hypoxic conditioning provides SIRT1-mediated protection against these network-specific FC deficits post-SAH, as does treatment with resveratrol. Conditioning-based strategies provide multifaceted neurovascular protection in experimental SAH.

Aims: The aim of this study was to determine the long-term mortality rate, and to identify factors associated with this, following primary and revision knee arthroplasty (KA)., Methods: Data from the Scottish Arthroplasty Project (1998 to 2019) were retrospectively analyzed. Patient mortality data were linked from the National Records of Scotland. Analyses were performed separately for the primary and revised KA cohorts. The standardized mortality ratio (SMR) with 95% confidence intervals (CIs) was calculated for the population at risk. Multivariable Cox proportional hazards were used to identify predictors and estimate relative mortality risks., Results: At a median 7.4 years (interquartile range (IQR) 4.0 to 11.6) follow-up, 27.8% of primary (n = 27,474/98,778) and 31.3% of revision (n = 2,611/8,343) KA patients had died. Both primary and revision cohorts had lower mortality rates than the general population (SMR 0.74 (95% CI 0.73 to 0.74); p < 0.001; SMR 0.83 (95% CI 0.80 to 0.86); p < 0.001, respectively), which persisted for 12 and eighteight years after surgery, respectively. Factors associated with increased risk of mortality after primary KA included male sex (hazard ratio (HR) 1.40 (95% CI 1.36 to 1.45)), increasing socioeconomic deprivation (HR 1.43 (95% CI 1.36 to 1.50)), inflammatory polyarthropathy (HR 1.79 (95% CI 1.68 to 1.90)), greater number of comorbidities (HR 1.59 (95% CI 1.51 to 1.68)), and periprosthetic joint infection (PJI) requiring revision (HR 1.92 (95% CI 1.57 to 2.36)) when adjusting for age. Similarly, male sex (HR 1.36 (95% CI 1.24 to 1.49)), increasing socioeconomic deprivation (HR 1.31 (95% CI 1.12 to 1.52)), inflammatory polyarthropathy (HR 1.24 (95% CI 1.12 to 1.37)), greater number of comorbidities (HR 1.64 (95% CI 1.33 to 2.01)), and revision for PJI (HR 1.35 (95% 1.18 to 1.55)) were independently associated with an increased risk of mortality following revision KA when adjusting for age., Conclusion: The SMR of patients undergoing primary and revision KA was lower than that of the general population and remained so for several years post-surgery. However, approximately one in four patients undergoing primary and one in three patients undergoing revision KA died within tenten years of surgery. Several patient and surgical factors, including PJI, were associated with the risk of mortality within ten years of primary and revision surgery. Cite this article: Bone Joint J  2022;104-B(1):45-52.

Background and Purpose: Early brain injury may be a more significant contributor to poor outcome after aneurysmal subarachnoid hemorrhage (aSAH) than vasospasm and delayed cerebral ischemia. However, studying this process has been hampered by lack of a means of quantifying the spectrum of injury. Global cerebral edema (GCE) is the most widely accepted manifestation of early brain injury but is currently assessed only through subjective, qualitative or semi-quantitative means. Selective sulcal volume (SSV), the CSF volume above the lateral ventricles, has been proposed as a quantitative biomarker of GCE, but is time-consuming to measure manually. Here we implement an automated algorithm to extract SSV and evaluate the age-dependent relationship of reduced SSV on early outcomes after aSAH., Methods: We selected all adults with aSAH admitted to a single institution with imaging within 72 hours of ictus. Scans were assessed for qualitative presence of GCE. SSV was automatically segmented from serial CTs using a deep learning-based approach. Early SSV was the lowest SSV from all early scans. Modified Rankin Scale score of 4 to 6 at hospital discharge was classified as a poor outcome., Results: Two hundred forty-four patients with aSAH were included. Sixty-five (27%) had GCE on admission while 24 developed it subsequently within 72 hours. Median SSV on admission was 10.7 mL but frequently decreased, with minimum early SSV being 3.0 mL (interquartile range, 0.3-11.9). Early SSV below 5 mL was highly predictive of qualitative GCE (area under receiver-operating-characteristic curve, 0.90). Reduced early SSV was an independent predictor of poor outcome, with a stronger effect in younger patients., Conclusions: Automated assessment of SSV provides an objective biomarker of GCE that can be leveraged to quantify early brain injury and dissect its impact on outcomes after aSAH. Such quantitative analysis suggests that GCE may be more impactful to younger patients with SAH.

Aims: The aim of this study was to measure the effect of hospital case volume on the survival of revision total knee arthroplasty (RTKA)., Methods: This is a retrospective analysis of Scottish Arthroplasty Project data, a nationwide audit which prospectively collects data on all arthroplasty procedures performed in Scotland. The primary outcome was RTKA survival at ten years. The primary explanatory variable was the effect of hospital case volume per year on RTKA survival. Kaplan-Meier survival curves were plotted with 95% confidence intervals (CIs) to determine the lifespan of RTKA. Multivariate Cox proportional hazards were used to estimate relative revision risks over time. Hazard ratios (HRs) were reported with 95% CI, and p-value < 0.05 was considered statistically significant., Results: From 1998 to 2019, 8,301 patients (8,894 knees) underwent RTKA surgery in Scotland (median age at RTKA 70 years (interquartile range (IQR) 63 to 76); median follow-up 6.2 years (IQR 3.0 to 10.2). In all, 4,764 (53.6%) were female, and 781 (8.8%) were treated for infection. Of these 8,894 knees, 957 (10.8%) underwent a second revision procedure. Male sex, younger age at index revision, and positive infection status were associated with need for re-revision. The ten-year survival estimate for RTKA was 87.3% (95% CI 86.5 to 88.1). Adjusting for sex, age, surgeon volume, and indication for revision, high hospital case volume was significantly associated with lower risk of re-revision (HR 0.78 (95% CI 0.64 to 0.94, p < 0.001)). The risk of re-revision steadily declined in centres performing > 20 cases per year; risk reduction was 16% with > 20 cases; 22% with > 30 cases; and 28% with > 40 cases. The lowest level of risk was associated with the highest volume centres., Conclusion: The majority of RTKA in Scotland survive up to ten years. Increasing yearly hospital case volume above 20 cases is independently associated with a significant risk reduction of re-revision. Development of high-volume tertiary centres may lead to an improvement in the overall survival of RTKA. Cite this article: Bone Joint J  2021;103-B(4):602-609.

Aims: The COVID-19 pandemic led to a national suspension of "non-urgent" elective hip and knee arthroplasty. The study aims to measure the effect of the COVID-19 pandemic on total hip arthroplasty (THA) and total knee arthroplasty (TKA) volume in Scotland. Secondary objectives are to measure the success of restarting elective services and model the time required to bridge the gap left by the first period of suspension., Methods: A retrospective observational study using the Scottish Arthroplasty Project dataset. All patients undergoing elective THAs and TKAs during the period 1 January 2008 to 31 December 2020 were included. A negative binomial regression model using historical case-volume and mid-year population estimates was built to project the future case-volume of THA and TKA in Scotland. The median monthly case volume was calculated for the period 2008 to 2019 (baseline) and compared to the actual monthly case volume for 2020. The time taken to eliminate the deficit was calculated based upon the projected monthly workload and with a potential workload between 100% to 120% of baseline., Results: Compared to the period 2008 to 2019, primary TKA and THA volume fell by 61.1% and 53.6%, respectively. Since restarting elective services, Scottish hospitals have achieved approximately 40% to 50% of baseline monthly activity. With no changes in current workload, by 2021 there would be a reduction of 9,180 and 10,170 for THA and TKA, respectively. Conversely, working at 120% baseline monthly output, it would take over four years to eliminate the deficit for both TKA and THA., Conclusion: This national study demonstrates the significant impact that COVID-19 pandemic has had on overall THA and TKA volume. In the six months after resuming elective services, Scottish hospitals averaged less than 50% normal monthly output. Loss of operating capacity will increase treatment delays and likely worsen overall morbidity. Cite this article: Bone Joint Open  2021;2(3):203-210.

Background and Purpose: Vasospasm and delayed cerebral ischemia (DCI) contribute significantly to the morbidity/mortality associated with aneurysmal subarachnoid hemorrhage (SAH). While considerable research effort has focused on preventing or reversing vasospasm, SAH-induced brain injury occurs in response to a multitude of concomitantly acting pathophysiologic mechanisms. In this regard, the pleiotropic epigenetic responses to conditioning-based therapeutics may provide an ideal SAH therapeutic strategy. We previously documented the ability of hypoxic preconditioning (PC) to attenuate vasospasm and neurological deficits after SAH, in a manner that depends on the activity of endothelial nitric oxide synthase. The present study was undertaken to elucidate whether the NAD-dependent protein deacetylase sirtuin isoform SIRT1 is an upstream mediator of hypoxic PC-induced protection, and to assess the efficacy of the SIRT1-activating polyphenol Resveratrol as a pharmacologic preconditioning therapy., Methods: Wild-type C57BL/6J mice were utilized in the study and subjected to normoxia or hypoxic PC. Surgical procedures included induction of SAH via endovascular perforation or sham surgery. Multiple endpoints were assessed including cerebral vasospasm, neurobehavioral deficits, SIRT1 expression via quantitative real-time PCR for mRNA, and western blot for protein quantification. Pharmacological agents utilized in the study include EX-527 (SIRT1 inhibitor), and Resveratrol (SIRT1 activator)., Results: Hypoxic PC leads to rapid and sustained increase in cerebral SIRT1 mRNA and protein expression. SIRT1 inhibition blocks the protective effects of hypoxic PC on vasospasm and neurological deficits. Resveratrol pretreatment dose-dependently abrogates vasospasm and attenuates neurological deficits following SAH - beneficial effects that were similarly blocked by pharmacologic inhibition of SIRT1., Conclusion: SIRT1 mediates hypoxic preconditioning-induced protection against neurovascular dysfunction after SAH. Resveratrol mimics this neurovascular protection, at least in part, via SIRT1. Activation of SIRT1 is a promising, novel, pleiotropic therapeutic strategy to combat DCI after SAH., (Copyright © 2020. Published by Elsevier Inc.)

Delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (SAH) has been associated with numerous pathophysiological sequelae, including large artery vasospasm and microvascular thrombosis. The focus of this review is to provide an overview of experimental animal model studies and human autopsy studies that explore the temporal-spatial characterization and mechanism of microvascular platelet aggregation and thrombosis following SAH, as well as to critically assess experimental studies and clinical trials highlighting preventative therapeutic options against this highly morbid pathophysiological process. Upon review of the literature, we discovered that microvascular platelet aggregation and thrombosis occur after experimental SAH across multiple species and SAH induction techniques in a similar time frame to other components of DCI, occurring in the cerebral cortex and hippocampus across both hemispheres. We discuss the relationship of these findings to human autopsy studies. In the final section of this review, we highlight the important therapeutic options for targeting microvascular platelet aggregation and thrombosis, and emphasize why therapeutic targeting of this neurovascular pathology may improve patient care. We encourage ongoing research into the pathophysiology of SAH and DCI, especially in regard to microvascular platelet aggregation and thrombosis and the translation to randomized clinical trials.

Background: Existing methods for assessment of total knee arthroplasty (TKA) component rotation on computed tomography (CT) scans are complex, especially in relation to the tibial component. Anecdotal evidence from our practice pointed towards a potential new landmark. The study aims were to check the prevalence of this landmark, define tibial component rotation in relation to it and demonstrate its reliability., Methods: Two hundred and eleven CTs undertaken following TKA were reviewed for presence of the landmark. A protocol to measure tibial component rotation in relation to this landmark was developed and the rotation measured using this method and Berger's protocol. Thirty one of the 211 CT scans were measured twice by two observers. Reliability was calculated using the Intraclass Correlation Coefficient (ICC)., Results: The new landmark of a flat area on the lateral cortex of the tibia inferior to the tibial component was identified on all scans. Median tibial component rotation measured using our protocol was 0.0° ± 5.4° and -9.2° ± 5.5° using Berger's protocol. Intra-observer reliability with the new method was excellent (ICCs of 0.899 and 0.871) and inter-observer reliability was good (ICCs of 0.734 and 0.836)., Conclusions: The new landmark had a very high prevalence and could be used to define tibial component rotation. This measurement of tibial component rotation had acceptable reliability. This landmark has potential for use in the radiological assessment of tibial component rotation following TKA. Further work is required to determine its relationship to anatomical structures and symptoms of tibial component mal-rotation., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Purpose: Knee alignment is a fundamental measurement in the assessment, monitoring and surgical management of patients with osteoarthritis. There is a lack of data regarding how static tibiofemoral alignment varies between supine and standing conditions. This study aimed to quantify the relationship between supine and standing lower limb alignment in asymptomatic, osteoarthritic (OA) and prosthetic (TKA) knees., Methods: A non-invasive position capture system was used to assess knee alignment for 30 asymptomatic controls and 31 patients with OA both before and after TKA. Coronal and sagittal mechanical femorotibial angles were measured supine with the lower limb in extension and in bipedal stance. Changes between conditions were analysed using paired ttests. Vector plots of ankle centre displacement relative to the knee centre from supine to standing were produced to allow three-dimensional visualisation., Results: All groups showed a trend towards varus and extension when going from supine to standing. Mean change for asymptomatic knees was 1.2° more varus (p = 0.001) and 3.8° more extended (p < 0.001). For OA knees this was 1.1° more varus (p = 0.009) and 5.9° more extended (p < 0.001) and TKA knees 1.9° more varus (p < 0.001) and 5.6° more extended (p < 0.001)., Conclusion: The observed consistent changes in lower limb alignment between supine and standing positions across knee types suggests the soft tissue envelope restraining the knee may have a greater influence on dynamic alignment changes than the underlying bony deformity. This highlights the importance of quantifying soft tissue behaviour when planning, performing and evaluating alignment dependent surgical interventions of the knee. When routinely assessing any type of knee, clinicians should be aware that subtle consistent alignment changes occur under weightbearing conditions and tailor their treatments accordingly., Level of Evidence: II.

Background: Surgical site infection (SSI) is a debilitating complication of lower limb arthroplasty with significant morbidity and increased costs. Numerous risk factors are associated with SSI., Methods: In an effort to identify novel risk factors for SSI, we undertook a retrospective cohort study of 1832 primary total hip arthroplasties and 2100 primary total knee arthroplasties performed in our high volume arthroplasty unit over a 2-year period., Results: Two risk factors were identified for SSI following total hip arthroplasty: body mass index ≥30 and peri-operative blood transfusion. Eight risk factors were identified for SSI following total knee arthroplasty: hypertension, peri-operative blood transfusion, skin closure using 2-octyl cyanoacrylate, use of oral steroids, reduced serum mean cell volume, reduced mean cell hemoglobin, elevated serum neutrophil count, and use of warfarin or rivaroxaban for venous thromboembolism prophylaxis., Conclusions: Our work proposes a number of previously undocumented risk factors in relation to SSI. Further investigation is required to ascertain the magnitude of their effect., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: This study compared knee alignment and laxity in patients before, during and after total knee arthroplasty, using methodologically similar procedures, with an aim to help inform pre-operative planning., Methods: Eighteen male and 13 female patients were recruited, mean age 66years (51-82) and mean body mass index of 33 (23-43). All were assessed pre- and postoperatively using a non-invasive infrared position capture system and all underwent total knee arthroplasty using a navigation system. Knee kinematic data were collected and comparisons made between preoperative clinical and intraoperative measurements for osteoarthritic knees, and between postoperative clinical and intraoperative measurements for prosthetic knees., Findings: There was no difference in unstressed coronal mechanical femoral-tibial angles for either osteoarthritic or prosthetic knees. However, for sagittal alignment the knees were in greater extension intraoperatively (osteoarthritic 5.2° p<0.001, prosthetic 7.2° p<0.001). For osteoarthritic knees, both varus and valgus stress manoeuvres had greater angular displacements intraoperatively by a mean value of 1.5° for varus (p=0.002) and 1.6° for valgus (p<0.001). For prosthetic knees, only valgus angular displacement was greater intraoperatively (0.9°, p=0.002)., Interpretation: Surgeons performing total knee arthroplasties should be aware of potential differences in alignment and laxity measured under different conditions to facilitate more accurate operative planning and follow-up., (Copyright © 2017. Published by Elsevier Ltd.)

Background: We describe a rare case of a sphenoid sinus myxoma that was resected via an endoscopic endonasal skull base approach. We review the literature regarding these rare tumors of the paranasal sinuses., Case Description: A 72-year-old woman was diagnosed with an incidental sphenoid sinus tumor and left sphenoid wing meningioma during a workup for left-sided proptosis and diplopia. Biopsies of the sphenoid wing and sphenoid sinus tumors were obtained. After undergoing surgical resection of the meningioma, the patient then underwent definitive resection of the sphenoid sinus myxoma via endoscopic endonasal skull base approach. Postoperative imaging demonstrated a gross total resection. The patient suffered postoperative thromboembolic complications due to underlying hypercoagulable state but made a complete recovery and returned to her neurologic baseline. There has been no evidence of recurrent myxoma in the sphenoid sinus 24 months after surgery., Discussion: Myxomas are benign tumors derived from primitive mesenchyme. Myxomas very rarely present in the paranasal or skull base location. Complete surgical resection is the primary treatment for these tumors. The endoscopic endonasal approach is an effective technique for resecting various benign and more aggressive extradural skull base tumors., Conclusions: Myxomas of the sphenoid sinus are rare. The endoscopic endonasal skull base approach is an effective and minimal access technique for resection of this rare tumor of the sphenoid sinus., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Alignment of normal, arthritic, and replaced human knees is a much debated subject as is the collateral ligamentous laxity. Traditional quantitative values have been challenged. Methods used to measure these are also not without flaws. Authors review the recent literature and a novel method of measurement of these values has been included. This method includes use of computer navigation technique in clinic setting for assessment of the normal or affected knee before the surgery. Computer navigation has been known for achievement of alignment accuracy during knee surgery. Now its use in clinic setting has added to the inventory of measurement methods. Authors dispel the common myth of straight mechanical axis in normal knees and also look at quantification of amount of collateral knee laxity. Based on the scientific studies, it has been shown that the mean alignment is in varus in normal knees. It changes from lying non-weight-bearing position to standing weight-bearing position in both coronal and the sagittal planes. It also varies with gender and race. The collateral laxity is also different for males and females. Further studies are needed to define the ideal alignment and collateral laxity which the surgeon should aim for individual knees.

The relationship between coronal knee laxity and the restraining properties of the collateral ligaments remains unknown. This study investigated correlations between the structural properties of the collateral ligaments and stress angles used in computer-assisted total knee arthroplasty (TKA), measured with an optically based navigation system. Ten fresh-frozen cadaveric knees (mean age: 81 ± 11 years) were dissected to leave the menisci, cruciate ligaments, posterior joint capsule and collateral ligaments. The resected femur and tibia were rigidly secured within a test system which permitted kinematic registration of the knee using a commercially available image-free navigation system. Frontal plane knee alignment and varus-valgus stress angles were acquired. The force applied during varus-valgus testing was quantified. Medial and lateral bone-collateral ligament-bone specimens were then prepared, mounted within a uni-axial materials testing machine, and extended to failure. Force and displacement data were used to calculate the principal structural properties of the ligaments. The mean varus laxity was 4 ± 1° and the mean valgus laxity was 4 ± 2°. The corresponding mean manual force applied was 10 ± 3 N and 11 ± 4 N, respectively. While measures of knee laxity were independent of the ultimate tensile strength and stiffness of the collateral ligaments, there was a significant correlation between the force applied during stress testing and the instantaneous stiffness of the medial (r = 0.91, p = 0.001) and lateral (r = 0.68, p = 0.04) collateral ligaments. These findings suggest that clinicians may perceive a rate of change of ligament stiffness as the end-point during assessment of collateral knee laxity.

Clinical laxity tests are used for assessing knee ligament injuries and for soft tissue balancing in total knee arthroplasty. This study reports the development and validation of a quantitative technique of assessing collateral knee laxity through accurate measurement of potential variables during routine clinical examination. The hypothesis was that standardisation of a clinical stress test would result in a repeatable range of laxity measurements. Non-invasive infrared tracking technology with kinematic registration of joint centres gave real-time measurement of both coronal and sagittal mechanical tibiofemoral alignment Knee flexion, moment arm and magnitude of the applied force were all measured and standardised. Three clinicians then performed six knee laxity examinations on a single volunteer using a target moment of 18 Nm. Standardised laxity measurements had small standard deviations (within 1. 1 degree) for each clinician and similar mean values between clinicians, with the valgus laxity assessment (mean of 3 degrees) being slightly more consistent than varus (means of 4 degrees or 5 degrees). The manual technique of coronal knee laxity assessment was successfully quantified and standardised, leading to a narrow range of measurements (within the accuracy of the measurement system). Minimising the subjective variables of clinical examination could improve current knowledge of soft tissue knee behaviour.

Objective: To assess current wound care practice, implement a potentially improved regimen and re-evaluate practice., Method: Two prospective clinical audits were performed over a 6-month period, involving 100 patients undergoing hip or knee arthroplasty. Fifty consecutive patients with traditional dressings (Mepore; Mölnlycke) were evaluated prior to a change in practice to a modern dressing (Aquacel Surgical; ConvaTec). Fifty consecutive patients were then evaluated with the new dressing to complete the audit cycle. Clinical outcome measures were wear time, number of changes, blister rate and length of hospital stay. Statistical comparisons were performed using Mann Whitney or Fisher's exact test (statistical significance p < 0.05)., Results: Wear time for the traditional dressing (2 days) was significantly shorter than for the modern dressing (7 days; p < 0.001), and required more changes (0 vs 3; p < 0.001). Twenty per cent of patients developed blisters with the traditional dressing compared with 4% with the modern dressing (p=0.028). Median length of stay was the same for the modern dressing (4 days) compared with the traditional dressing (4 days). In the modern dressing group, 75% of patients were discharged by day 4, whereas in the traditional group this took until day 6., Conclusion: This audit highlights the problems associated with traditional dressings with frequent early dressing changes, blistering and delayed discharge. These adverse outcomes can be minimised with a modern dressing specifically designed for the demands of lower limb arthroplasty. Units planning to implement enhanced recovery regimens should consider adopting this dressing to avoid compromising patient discharge., Declaration of Interest: There were no external sources of funding for this audit; however, one author (JC) received reimbursement of expenses to attend and present work at educational conferences from ConvaTec.

The quantification of knee alignment is a routine part of orthopaedic practice and is important for monitoring disease progression, planning interventional strategies, and follow-up of patients. Currently available technologies such as radiographic measurements have a number of drawbacks. The aim of this study was to validate a potentially improved technique for measuring knee alignment under different conditions. An image-free navigation system was adapted for non-invasive use through the development of external infrared tracker mountings. Stability was assessed by comparing the variance (F-test) of repeated mechanical femoro-tibial (MFT) angle measurements for a volunteer and a leg model. MFT angles were then measured supine, standing and with varus-valgus stress in asymptomatic volunteers who each underwent two separate registrations and repeated measurements for each condition. The mean difference and 95% limits of agreement were used to assess intra-registration and inter-registration repeatability. For multiple registrations the range of measurements for the external mountings was 1° larger than for the rigid model with statistically similar variance (p=0.34). Thirty volunteers were assessed (19 males, 11 females) with a mean age of 41 years (range: 20-65) and a mean BMI of 26 (range: 19-34). For intra-registration repeatability, consecutive coronal alignment readings agreed to almost ±1°, with up to ±0.5° loss of repeatability for coronal alignment measured before and after stress maneuvers, and a ±0.2° loss following stance trials. Sagittal alignment measurements were less repeatable overall by an approximate factor of two. Inter-registration agreement limits for coronal and sagittal supine MFT angles were ±1.6° and ±2.3°, respectively. Varus and valgus stress measurements agreed to within ±1.3° and ±1.1°, respectively. Agreement limits for standing MFT angles were ±2.9° (coronal) and ±5.0° (sagittal), which may have reflected a variation in stance between measurements. The system provided repeatable, real-time measurements of coronal and sagittal knee alignment under a number of dynamic, real-time conditions, offering a potential alternative to radiographs.

Perilunate dislocations and fracture dislocations represent uncommon and unusual injuries that are often missed at initial presentation and diagnosed late in up to 25% of cases. Prompt open reduction, carpal stabilisation and ligamentous repair is required to reduce the risk of complications. We report a case of an established scaphoid non-union in an operatively managed perilunate fracture dislocation that spontaneously united almost 2 years after the initial injury, just before a planned revision scaphoid fixation with bone grafting. This case highlights the importance of initial clinical assessment together with appropriate radiographs and follow-up of these injuries post-operatively, especially when complications such as non-union arise.

Computer Assisted Orthopaedic Surgery (CAOS) technology is constantly evolving with support from a growing number of clinical trials. In contrast, reports of technical accuracy are scarce, with there being no recognized guidelines for independent measurement of the basic static performance of computer assisted systems. To address this problem, a group of surgeons, academics and manufacturers involved in the field of CAOS collaborated with the American Society for Testing and Materials (ASTM) International and drafted a set of standards for measuring and reporting the technical performance of such systems. The aims of this study were to use these proposed guidelines in assessing the positional accuracy of both a commercially available and a novel tracking system. A standardized measurement object model based on the ASTM guidelines was designed and manufactured to provide an array of points in space. Both the Polaris camera with associated active infrared trackers and a novel system that used a small visible-light camera (MicronTracker) were evaluated by measuring distances and single point repeatability. For single point registration the measurements were obtained both manually and with the pointer rigidly clamped to eliminate human movement artifact. The novel system produced unacceptably large distance errors and was not evaluated beyond this stage. The commercial system was precise and its accuracy was well within the expected range. However, when the pointer was held manually, particularly by a novice user, the results were significantly less precise by a factor of almost ten. The ASTM guidelines offer a simple, standardized method for measuring positional accuracy and could be used to enable independent testing of tracking systems. The novel system demonstrated a high level of inaccuracy that made it inappropriate for clinical testing. The commercially available tracking system performed well within expected limits under optimal conditions, but revealed a surprising loss of accuracy when movement artifacts were introduced. Technical validation of systems may give the user community more confidence in CAOS systems as well as highlighting potential sources of point registration error.

An audit of wound healing in patients undergoing total hip or knee arthroplasty in a Scottish hospital found that use of a barrier film made no difference to the effectiveness of a new Hydrofiber/hydrocolloid dressing combination.

1. In eggs turned about 12 times daily, around the long axis of the egg and through about 180 degrees, significant increases in heart rate occurred during turning on the 15th and 17th, although not on the 16th, d of incubation. 2. On and after the 18th d heart rate increases were more marked and occurred both during and after turning. 3. When a single group of embryos was turned every day for the last 4 d of incubation there were significant increases in heart rate on the last 3 d: this repeated retesting had no effect on the response to turning.