Retention of the posterior cruciate ligament stabilizes the medial femoral condyle during kneeling using a tibial insert with ball-in-socket medial conformity.

PURPOSE: Resecting the posterior cruciate ligament (PCL) increases posterior laxity and increases the flexion gap more than the extension gap in the native (i.e. healthy) knee. These two effects could lead to significant anterior displacement of the medial femoral condyle in kneeling following total knee arthroplasty even when using a tibial insert with a high degree of medial conformity. Using an insert with ball-in-socket medial conformity and a flat lateral articular surface, the primary purpose was to determine whether the medial femoral condyle remained stable with and without PCL retention during kneeling. METHODS: Two groups of patients were studied, one with PCL retention (22 patients) and the other with PCL resection (25 patients), while kneeling at 90º flexion. Following 3D model-to-2D image registration, A-P displacements of both femoral condyles were determined relative to the dwell point of the medial socket. RESULTS: With PCL resection versus PCL retention, the medial femoral condyle was 5.1 ± 3.7 mm versus 0.8 ± 2.1 mm anterior of the dwell point (p < 0.0001). Patient-reported function scores were comparable (p ≥ 0.1610) despite a significantly shorter follow-up of 7.8 ± 0.9 months with PCL retention than 19.6 ± 4.9 months with PCL resection (p < 0.0001). Range of motion was 126 ± 8° versus 122 ± 6° with and without PCL retention, respectively (p = 0.057). CONCLUSION: Surgeons that use a highly conforming tibial insert design can stabilize the medial femoral condyle during kneeling by retaining the PCL. In patients with PCL resection, the 9 mm high anterior lip of the insert with ball-in-socket medial conformity was insufficient to prevent significant anterior displacement of the medial femoral condyle when weight-bearing on the anterior tibia.

The peak force to push a trial tibial insert into position cannot be used to select the correct thickness in total knee arthroplasty.

An objective of a total knee arthroplasty (TKA) is to restore native (i.e. healthy) function, and a crucial step is determining the correct insert thickness for each patient. If the insert is too thick, then stiffness results, and if too thin, then instability results. Two methods to determine the insert thickness are by manually assessing the joint laxity and by using a trial insert with goniometric markings that measures the internal-external rotation of the trial with respect to a mark on the femoral component. The former is qualitative and depends on the surgeon's experience and 'feel' and while the latter is quantitative, it can be used only with an insert with medial ball-in-socket conformity. An unexplored method is to measure the force required to push a trial insert into position. To determine whether this method has merit, the push force was measured in 30 patients undergoing unrestricted kinematically aligned TKA using an insert with ball-in-socket medial conformity, a flat lateral surface, and retention of the posterior cruciate ligament. During surgery, the surgeon determined three appropriate thicknesses to test from a selection ranging from 10 mm to 14 mm in 1 mm increments. The peak push forces going from an insert 1 mm thinner than the correct thickness as determined by an insert goniometer and from the correct thickness to 1 mm thicker were measured. Mean peak forces for the different insert thicknesses were 127 ± 104 N, 127 ± 95 N, and 144 ± 96 N for 1 mm thinner, correct, and 1 mm thicker, respectively, and did not differ (p = 0.3210). As a result, measurement of peak force during trial positioning of a tibial insert cannot be used to identify the correct thickness for all insert designs.

Finding Order in Chaos: Quantitative Predictors of Chaos Terrain Morphology on Europa.

The mechanisms for chaos terrain formation on Europa have long been a source of debate in the scientific community. There exist numerous theoretical and numerical models for chaos formation, but to date there has been a lack of quantifiable observations that can be used to constrain models and permit comparison to the outputs of these chaos models. Here, we use mapping and statistical analysis to develop a quantitative description of chaos terrain and their observed morphologies. For nine chaos features, we map every block, or region of pre-existing terrain within disrupted matrix. We demonstrate that chaos terrains follow a continuous spectrum of morphologies between two endmembers, platy and knobby. We find that any given chaos terrain's morphology can be quantified by means of the linearized exponential slope of its cumulative block area distribution. This quantitative metric provides a new diagnostic parameter in future studies of chaos terrain formation and comparison.

Prospective observational cohort study of the association between antiplatelet therapy, bleeding and thrombosis in patients with coronary stents undergoing noncardiac surgery.

BACKGROUND: The perioperative management of antiplatelet therapy in noncardiac surgery patients who have undergone previous percutaneous coronary intervention (PCI) remains a dilemma. Continuing dual antiplatelet therapy (DAPT) may carry a risk of bleeding, while stopping antiplatelet therapy may increase the risk of perioperative major adverse cardiovascular events (MACE). METHODS: Occurrence of Bleeding and Thrombosis during Antiplatelet Therapy In Non-Cardiac Surgery (OBTAIN) was an international prospective multicentre cohort study of perioperative antiplatelet treatment, MACE, and serious bleeding in noncardiac surgery. The incidences of MACE and bleeding were compared in patients receiving DAPT, monotherapy, and no antiplatelet therapy before surgery. Unadjusted risk ratios were calculated taking monotherapy as the baseline. The adjusted risks of bleeding and MACE were compared in patients receiving monotherapy and DAPT using propensity score matching. RESULTS: A total of 917 patients were recruited and 847 were eligible for inclusion. Ninety-six patients received no antiplatelet therapy, 526 received monotherapy with aspirin, and 225 received DAPT. Thirty-two patients suffered MACE and 22 had bleeding. The unadjusted risk ratio for MACE in patients receiving DAPT compared with monotherapy was 1.9 (0.93-3.88), P=0.08. There was no difference in MACE between no antiplatelet treatment and monotherapy 1.03 (0.31-3.46), P=0.96. Bleeding was more frequent with DAPT 6.55 (2.3-17.96) P=0.0002. In a propensity matched analysis of 177 patients who received DAPT and 177 monotherapy patients, the risk ratio for MACE with DAPT was 1.83 (0.69-4.85), P=0.32. The risk of bleeding was significantly greater in the DAPT group 4.00 (1.15-13.93), P=0.031. CONCLUSIONS: OBTAIN showed an increased risk of bleeding with DAPT and found no evidence for protective effects of DAPT from perioperative MACE in patients who have undergone previous PCI.

Paediatric antiepileptic polytherapy: systematic review of efficacy and neurobehavioural effects and a tertiary centre experience.

AIM: This paper presents the prevalence of antiepileptic polytherapy at a single tertiary institution and systematically reviews the evidence base for its efficacy and neurobehavioural safety in children. METHOD: Prevalence of antiepileptic polypharmacy was determined from pharmacy dispensing records at a paediatric tertiary hospital and neurobehavioural comorbidities quantified through casenote review; comparison is made with studies evaluating the neurobehavioural safety of antiepileptic polytherapy, identified via systematic literature review. RESULTS: Amongst 262 patients at the hospital, 117 (44.7%) were prescribed polytherapy; with patients having an intellectual disability statistically more likely to be prescribed polytherapy than those without (70.5% vs 40.6%; p < 0.0001). Systematic review identified no trials addressing the efficacy or neurobehavioural outcomes of polytherapy as a primary outcome. Several observational studies identified associations between polytherapy and neurobehavioural adverse outcomes such as anxiety and behavioural disturbance. Observational studies also suggest that a reduction in polytherapy load is generally not associated with worsening seizure control. CONCLUSION: Whilst antiepileptic polytherapy is common practice within paediatric epilepsy cohorts attending tertiary care institutions, evidence is lacking to support its efficacy. There are significant practical difficulties to undertaking randomised controlled trials within this population. Nonetheless, clinicians must consider that adverse neurobehavioural consequences of polytherapy might outweigh benefits to seizure control.

Abdominal aortic aneurysm repair in the United Kingdom: an exemplar for the role of anaesthetists in perioperative medicine.

The past two decades have seen an increasing recognition that the delivery of safe surgery with low complication rates and good long-term outcomes is a team endeavour embracing the whole patient care pathway. The key role of the anaesthetist in managing the patient through the surgical process is widely understood and has driven the emergence of perioperative medicine. In parallel with these developments there has been a sea change in the organisation of the care of patients presenting for elective abdominal aortic aneurysm (AAA) repair. Data from the 2008 report of the VASCUNET vascular registry suggested that the UK had the highest mortality for elective open AAA repair in Europe (7.9%). In response, a national quality improvement programme (AAAQIP) spanning the disciplines of surgery, anaesthesia, radiology and nursing was put in place. This led to significant changes in all aspects of AAA repair including the role of the anaesthetist. Preoperative assessment by an anaesthetist with a vascular practice was mandated and the role of the anaesthetist in the vascular multidisciplinary team meeting (MDT) established. Anaesthetic data were included in the national data collection system for vascular surgery, the National Vascular Registry. These changes paralleled and in some cases led the wider evolution of the role of the anaesthetist in perioperative medicine. The mortality from infrarenal AAA repair in the UK decreased to 2.4% by 2012. This improvement reflects changes in perioperative care supported and in some cases led by anaesthetists.

Anterior laxity and patient-reported outcomes 7 years after ACL reconstruction with a fresh-frozen tibialis allograft.

PURPOSE: After reconstructing a torn ACL with a soft tissue allograft, the long-term healing process of graft maturation following the short-term healing process of graft incorporation into the bone tunnels might lead to recurring instability and concomitant decreases in the activity level, function, and patient satisfaction. Relying on roentgen stereophotogrammetric analysis (RSA), the primary purpose was to determine whether anterior laxity increased and whether patient-reported outcomes declined between 1 and 7 years for a particular graft construct, surgical technique, and rehabilitation programme. METHODS: Eighteen of 19 patients, who participated in an earlier RSA study which extended to 1 year after the surgical procedure, were contacted 7 years after the surgical procedure. An examiner, different from the treating surgeon, measured anterior laxity under 150 N of anterior force using RSA in 16 patients and obtained outcome scores in 17 patients. One patient moved abroad and could not be contacted. One patient reinjured his reconstructed ACL and was excluded. RESULTS: The average increase in anterior laxity of 1.5 ± 2.1 mm between 1 and 7 years after surgery was not significant (p = 0.08), and the average increase in anterior laxity of 2.7 ± 2.3 mm between the day of surgery and 7 years was significant (p < 0.001). There were no significant declines in activity (median Tegner score, 6 at 1 year, 6 at 7 years), function (average Lysholm score, 94 at 1 year, 91 at 7 years), and subjective satisfaction (average International Knee Documentation Committee score, 90 at 1 year, 87 at 7 years) between 1 and 7 years after surgery. CONCLUSION: In demonstrating that the ACL graft construct remains functional in the long term, this study supports the use of a fresh-frozen tibialis allograft in patients with an average age of 37 years at the time of surgery when used in conjunction with a surgical technique which avoids roof and PCL impingement, uses slippage-resistant fixation devices, and allows brace-free, self-paced rehabilitation. LEVEL OF EVIDENCE: IV.

Low prevalence of HER2 positivity amongst BRCA1 and BRCA2 mutation carriers and in primary BRCA screens.

The aim of this study is to delineate more clearly the prevalence of HER2+ breast cancer in women with germline BRCA1/2 mutations. For this purpose, we analysed primary mutation screens on women with breast cancer with unequivocal HER2 amplification and assessed the proportion of BRCA1 and BRCA2 breast cancers that were HER2+ comparing this with the existing literature. The results are that 1063 primary BRCA screens had confirmed tumour HER2 status. If HER2+ only 2.5 % (4/156) and 3.2 % (5/156) of women had a BRCA1 or BRCA2 mutation identified respectively; compared to 27.7 % (115/415) and 8.2 % (34/415) with triple negative tumours. Only 2.1 % (4/195) women with BRCA1-related breast cancer had HER2 amplified breast cancers rising to 6.8 % (n = 12, p = 0.04) in BRCA2. These rates are in keeping with most of the existing literature except a recent large multicenter report which documented higher rates but with no control group. The study concluded that true HER2-amplified breast cancers are rare amongst BRCA1 mutation carriers and are less common in BRCA2 than background rates.

Effect of supervised aerobic exercise rehabilitation on physical fitness and quality-of-life in survivors of critical illness: an exploratory minimized controlled trial (PIX study).

BACKGROUND: Evidence is limited for the effectiveness of interventions for survivors of critical illness after hospital discharge. We explored the effect of an 8-week hospital-based exercise-training programme on physical fitness and quality-of-life. METHODS: In a parallel-group minimized controlled trial, patients were recruited before hospital discharge or in the intensive care follow-up clinic and enrolled 8-16 weeks after discharge. Each week, the intervention comprised two sessions of physiotherapist-led cycle ergometer exercise (30 min, moderate intensity) plus one equivalent unsupervised exercise session. The control group received usual care. The primary outcomes were the anaerobic threshold (in ml O2 kg(-1) min(-1)) and physical function and mental health (SF-36 questionnaire v.2), measured at Weeks 9 (primary time point) and 26. Outcome assessors were blinded to group assignment. RESULTS: Thirty patients were allocated to the control and 29 to the intervention. For the anaerobic threshold outcome at Week 9, data were available for 17 control vs 13 intervention participants. There was a small benefit (vs control) for the anaerobic threshold of 1.8 (95% confidence interval, 0.4-3.2) ml O2 kg(-1) min(-1). This advantage was not sustained at Week 26. There was evidence for a possible beneficial effect of the intervention on self-reported physical function at Week 9 (3.4; -1.4 to 8.2 units) and on mental health at Week 26 (4.4; -2.4 to 11.2 units). These potential benefits should be examined robustly in any subsequent definitive trial. CONCLUSIONS: The intervention appeared to accelerate the natural recovery process and seems feasible, but the fitness benefit was only short term. CLINICAL TRIAL REGISTRATION: Current Controlled Trials ISRCTN65176374 (http://www.controlled-trials.com/ISRCTN65176374).

Design, calibration and validation of a novel 3D printed instrumented spatial linkage that measures changes in the rotational axes of the tibiofemoral joint.

An accurate axis-finding technique is required to measure any changes from normal caused by total knee arthroplasty in the flexion-extension (F-E) and longitudinal rotation (LR) axes of the tibiofemoral joint. In a previous paper, we computationally determined how best to design and use an instrumented spatial linkage (ISL) to locate the F-E and LR axes such that rotational and translational errors were minimized. However, the ISL was not built and consequently was not calibrated; thus the errors in locating these axes were not quantified on an actual ISL. Moreover, previous methods to calibrate an ISL used calibration devices with accuracies that were either undocumented or insufficient for the device to serve as a gold-standard. Accordingly, the objectives were to (1) construct an ISL using the previously established guidelines,(2) calibrate the ISL using an improved method, and (3) quantify the error in measuring changes in the F-E and LR axes. A 3D printed ISL was constructed and calibrated using a coordinate measuring machine, which served as a gold standard. Validation was performed using a fixture that represented the tibiofemoral joint with an adjustable F-E axis and the errors in measuring changes to the positions and orientations of the F-E and LR axes were quantified. The resulting root mean squared errors (RMSEs) of the calibration residuals using the new calibration method were 0.24, 0.33, and 0.15 mm for the anterior-posterior, medial-lateral, and proximal-distal positions, respectively, and 0.11, 0.10, and 0.09 deg for varus-valgus, flexion-extension, and internal-external orientations, respectively. All RMSEs were below 0.29% of the respective full-scale range. When measuring changes to the F-E or LR axes, each orientation error was below 0.5 deg; when measuring changes in the F-E axis, each position error was below 1.0 mm. The largest position RMSE was when measuring a medial-lateral change in the LR axis (1.2 mm). Despite the large size of the ISL, these calibration residuals were better than those for previously published ISLs, particularly when measuring orientations, indicating that using a more accurate gold standard was beneficial in limiting the calibration residuals. The validation method demonstrated that this ISL is capable of accurately measuring clinically important changes (i.e. 1 mm and 1 deg) in the F-E and LR axes.

Appreciating the links between heart failure and depression.

Depression and heart failure frequently occur together, symptoms overlap and the prognosis is worsened. Both conditions share biopsychosocial risk factors and are accompanied by behavioural/lifestyle, neurohormonal, inflammatory and autonomic changes that are implicated aetiologically. Depression has been conceptualized as a decompensated response to allostatic overload, wherein adaptive psychological, behavioural and physiological responses to chronic and/or severe stress, become unsustainable. Heart failure can similarly be viewed as a decompensated response to circulatory overload, wherein adaptive functional (neurohormonal effects on circulation, inotropic effects on heart) and structural (myocardial remodelling) changes, become unsustainable. It has been argued that the disengaged state of depression can initially be protective, limiting an individual's exposure to external challenges, such that full recovery is often possible. In contrast, heart failure, once past a tipping-point, can progress relentlessly. Here, we consider the bidirectional interactions between depression and heart failure. Targeted treatment of depression in the context of heart failure may improve quality of life, yet overall benefits on mortality remain elusive. However, effective treatment of heart failure typically enhances function and improves key psychological and behavioural determinants of low mood. Prospectively, research that examines the mechanistic associations between depression and heart failure offers fresh opportunity to optimize personalized management in the advent of newer interventions for both conditions.

Capivasertib and fulvestrant for patients with hormone receptor-positive advanced breast cancer: characterization, time course, and management of frequent adverse events from the phase III CAPItello-291 study.

BACKGROUND: Capivasertib is a potent, selective pan-AKT inhibitor. In CAPItello-291, the addition of capivasertib to fulvestrant resulted in a statistically significant (P < 0.001) improvement in progression-free survival over fulvestrant monotherapy in patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative advanced breast cancer and disease progression on or after aromatase inhibitor-based therapy. Characterization of the capivasertib-fulvestrant adverse event (AE) profile as managed in CAPItello-291 can inform future management guidance and optimize clinical benefit. PATIENTS AND METHODS: Seven hundred and eight patients were randomized 1 : 1 to capivasertib (400 mg twice daily; 4 days on, 3 days off) or placebo, plus fulvestrant, on a 4-week cycle. Dose reductions/interruptions for capivasertib/placebo were permitted (up to two dose reductions). Safety analyses included exposure, AE, and clinical laboratory data and were conducted in patients who received at least one dose of capivasertib, fulvestrant, or placebo. Frequent AEs associated with phosphoinositide 3-kinase (PI3K)/protein kinase (AKT) pathway inhibition (diarrhea, rash, hyperglycemia) were characterized using group terms. AEs were summarized using descriptive statistics; time-to-event analyses were conducted. RESULTS: Safety analyses included 705 patients: capivasertib-fulvestrant (n = 355) and placebo-fulvestrant (n = 350). Frequent any-grade AEs with capivasertib-fulvestrant were diarrhea (72.4%), rash (38.0%), and nausea (34.6%); frequent grade ≥3 AEs were rash (12.1%), diarrhea (9.3%), and hyperglycemia (2.3%). Diarrhea, rash, and hyperglycemia occurred shortly after starting capivasertib-fulvestrant [median days to onset (interquartile range) of any grade: 8 (2-22), 12 (10-15), and 15 (1-51), respectively], and were managed with supportive medications, dose reductions, interruptions, and/or discontinuation. Discontinuation rates were 2.0%, 4.5%, and 0.3%, respectively. Overall, 13.0% discontinued capivasertib due to AEs. CONCLUSIONS: Frequent AEs associated with PI3K/AKT pathway inhibition occurred early and were manageable. The low rate of treatment discontinuations suggests that, when appropriately managed, these AEs do not pose a challenge to clinical benefit.

Meta-analysis of prospective trials determining the short- and mid-term effect of elective open and endovascular repair of abdominal aortic aneurysms on quality of life.

BACKGROUND: Repair of an abdominal aortic aneurysm (AAA) is undertaken to prevent rupture. Intervention is by either open repair (OR) or a more minimally invasive endovascular repair (EVAR). Quality-of-life (QoL) analysis is an important health outcome and a number of single studies have assessed QoL following OR and EVAR. This was a meta-analysis of published studies to assess the effect of an intervention on QoL in patients with an AAA. METHODS: A systematic literature search was undertaken for studies prospectively reporting QoL analysis in patients with an AAA undergoing elective intervention. A multivariable meta-analysis model was developed in which the outcomes were mean changes in QoL scores over time, both for all AAA repairs (OR and EVAR) and comparing OR with EVAR. RESULTS: Data were collated from 16 studies (14 OR, 12 EVAR). The results suggested that treating an AAA had an effect on patient-reported QoL, evident from the statistically significant changes predominantly in domains assessing physical ability and pain. QoL was affected most within the first 3 months after any form of intervention, and was more pronounced following OR. Furthermore, a deterioration in the Physical Component Summary score following an AAA repair (either OR or EVAR) was evident at 12 months after intervention. CONCLUSION: Treating an AAA deleteriously affects patient-reported QoL over the first year following intervention.

Optimized design of an instrumented spatial linkage that minimizes errors in locating the rotational axes of the tibiofemoral joint: a computational analysis.

An accurate method to locate of the flexion-extension (F-E) axis and longitudinal rotation (LR) axis of the tibiofemoral joint is required to accurately characterize tibiofemoral kinematics. A method was recently developed to locate these axes using an instrumented spatial linkage (ISL) (2012, "On the Estimate of the Two Dominant Axes of the Knee Using an Instrumented Spatial Linkage," J. Appl. Biomech., 28(2), pp. 200-209). However, a more comprehensive error analysis is needed to optimize the design and characterize the limitations of the device before using it experimentally. To better understand the errors in the use of an ISL in finding the F-E and LR axes, our objectives were to (1) develop a method to computationally determine the orientation and position errors in locating the F-E and LR axes due to transducer nonlinearity and hysteresis, ISL size and attachment position, and the pattern of applied tibiofemoral motion, (2) determine the optimal size and attachment position of an ISL to minimize these errors, (3) determine the best pattern of pattern of applied motion to minimize these errors, and (4) examine the sensitivity of the errors to range of flexion and internal-external (I-E) rotation. A mathematical model was created that consisted of a virtual "elbow-type" ISL that measured motion across a virtual tibiofemoral joint. Two orientation and two position errors were computed for each axis by simulating the axis-finding method for 200 iterations while adding transducer errors to the revolute joints of the virtual ISL. The ISL size and position that minimized these errors were determined from 1080 different combinations. The errors in locating the axes using the optimal ISL were calculated for each of three patterns of motion applied to the tibiofemoral joint, consisting of a sequential pattern of discrete tibiofemoral positions, a random pattern of discrete tibiofemoral positions, and a sequential pattern of continuous tibiofemoral positions. Finally, errors as a function of range of flexion and I-E rotation were determined using the optimal pattern of applied motion. An ISL that was attached to the anterior aspect of the knee with 300-mm link lengths had the lowest maximum error without colliding with the anatomy of the joint. A sequential pattern of discrete tibiofemoral positions limited the largest orientation or position error without displaying large bias error. Finally, the minimum range of applied motion that ensured all errors were below 1 deg or 1 mm was 30 deg flexion with ±15 deg I-E rotation. Thus a method for comprehensive analysis of error when using this axis-finding method has been established, and was used to determine the optimal ISL and range of applied motion; this method of analysis could be used to determine the errors for any ISL size and position, any applied motion, and potentially any anatomical joint.

Dermatopathology and the Diagnosis of Fungal Infections.

Diagnosis of superficial/cutaneous fungal infections from skin, hair and nail samples is generally achieved using microscopy and culture in a microbiology laboratory, however, any presentation that is unusual or subcutaneous is sampled by taking a biopsy. Using histological techniques a tissue biopsy enables a pathologist to perform a full examination of the skin structure, detect any inflammatory processes or the presence of an infectious agent or foreign body. Histopathological examination can give a presumptive diagnosis while a culture result is pending, and may provide valuable diagnostic information if culture fails. This review demonstrates how histopathology contributes to the diagnosis of fungal infections from the superficial to the life threatening.

Evolving relationship of Nares Strait ice arches on sea ice along the Strait and the North Water, the Arctic's most productive polynya.

Nares Strait, the waterway that separates northwest Greenland from Ellesmere Island, is a major pathway along which sea ice leaves the Arctic, including the planet's oldest and thickest sea ice that is experiencing an accelerated loss. Ice arches that develop during the winter at the Strait's northern or southern terminus can remain stable for months at a time during which the transport of sea ice ceases. The Arctic's most productive polynya, the North Water (NOW) or Pikialasorsuaq (West Greenlandic for 'great upwelling') forms at the Strait's southern end. There is evidence that a warming climate and the concomitant thinning of Arctic sea ice is weakening the arches and it has been proposed that this may impact the stability of NOW and the complex ecosystem that it sustains. Here we employ a categorization of recent winters with respect to the presence or absence of ice arches to explore their impact on sea ice along the Strait and over the NOW. We find that winters during which a southern ice arch is absent are associated with a reduced and thinner ice cover along the Strait with ice conditions over the NOW similar to that during winters with a southern arch. In winters, without a southern arch, there is also an acceleration of the winds along the Strait that contributes to the presence of reduced ice cover. Ocean color remote sensing data suggests that current levels of primary productivity over the NOW are independent of the presence or absence of an ice arch. The results suggest more research is needed to assess the stability of the NOW, with respect to reduced ice cover and primary productivity, in a future where ice arches cease to form along Nares Strait.

Posterior cruciate ligament retention with medial ball-in-socket conformity promotes internal tibial rotation and knee flexion while providing high clinical outcome scores.

BACKGROUND: Although retaining the posterior cruciate ligament (PCL) is advantageous in unrestricted kinematically aligned TKA, it is often excised with a medial stabilized implant. The primary objectives were to determine whether PCL retention using an insert with ball-in-socket (B-in-S) medial conformity to maximize A-P stability promotes internal tibial rotation and flexion while providing high patient-reported outcome scores. METHODS: Two cohorts of 25 patients each were treated with unrestricted kinematically aligned (KA) TKA using a tibial insert with B-in-S medial conformity and a flat lateral articular surface. One cohort retained the PCL; the other had it excised. Patients performed deep knee bend and step-up exercises during fluoroscopic imaging. Following 3D model-to-2D image registration, anterior-posterior (A-P) positions of the femoral condyles and tibial rotation were determined. RESULTS: For deep knee bend, mean internal tibial rotation with PCL retention was significantly greater at maximum flexion (17.7° ± 5.7° versus 10.4° ± 6.5°, p < 0.001) and significantly greater at 30°, 60°, and 90° flexion as well (p ≤ 0.0283). For step-up, mean internal tibial rotation with PCL retention was significantly greater at at 15°, 30°, and 45° flexion (p ≤ 0.0049) but was marginally not significantly greater at 60° (i.e. maximum) flexion (12.3° ± 4.4° versus 10.1° ± 5.4°, p = 0.0794). Mean flexion during active knee flexion with PCL retention was significantly greater (127° ± 8° versus 122° ± 6°, p = 0.0400). Both cohorts had high median Oxford Knee, WOMAC, and Forgotten Joint Scores that were not significantly different (p = 0.0918, 0.1448, and 0.0855, respectively) CONCLUSION: Surgeons that perform unrestricted KA TKA should retain the PCL with an insert that has B-in-S medial conformity, as this maintains extension and flexion gaps while also promoting internal tibial rotation and knee flexion as well as providing high clinical outcome scores.

Process, structural, and outcome quality indicators to support perioperative opioid stewardship: a rapid review.

Opioids are effective analgesics but can cause harm. Opioid stewardship is key to ensuring that opioids are used effectively and safely. There is no agreed set of quality indicators relating to the use of opioids perioperatively. This work is part of the Yorkshire Cancer Research Bowel Cancer Quality Improvement programme and aims to develop useful quality indicators for the improvement of care and patient outcomes at all stages of the perioperative journey.A rapid review was performed to identify original research and reviews in which quality indicators for perioperative opioid use are described. A data tool was developed to enable reliable and reproducible extraction of opioid quality indicators.A review of 628 abstracts and 118 full-text publications was undertaken. Opioid quality indicators were identified from 47 full-text publications. In total, 128 structure, process and outcome quality indicators were extracted. Duplicates were merged, with the final extraction of 24 discrete indicators. These indicators are based on five topics: patient education, clinician education, pre-operative optimization, procedure, and patient-specific prescribing and de-prescribing and opioid-related adverse drug events.The quality indicators are presented as a toolkit to contribute to practical opioid stewardship. Process indicators were most commonly identified and contribute most to quality improvement. Fewer quality indicators relating to intraoperative and immediate recovery stages of the patient journey were identified. An expert clinician panel will be convened to agree which of the quality indicators identified will be most valuable in our region for the management of patients undergoing surgery for bowel cancer.