P869Predictive value of the endothelial shear stress distribution in three-dimensional quantitative coronary angiography models in detecting vulnerable plaques

Background

Low Endothelial shear stress (ESS) is a well-known instigator of coronary atherosclerosis. Prospective intravascular ultrasound (IVUS)-based imaging studies with computational fluid dynamic analysis revealed its predictive merit in-vivo. However, whether coronary modelling derived from quantitative coronary angiography (QCA) is equally effective in detecting high-risk plaques remains to be established.

Purpose

To examine the value of endothelial shear stress (ESS) estimated in three-dimensional (3D) QCA models in detecting plaques that are likely to progress and cause events.

Method

We analysed the baseline intravascular ultrasound virtual histology (IVUS-VH) and angiographic data from 28 non-culprit lesions with a vulnerable phenotype (i.e., fibroatheroma or thin cap fibroatheroma) that caused major adverse cardiac events or required revascularization (nc-MACE-R) at 5-year follow-up and from a control group of 119 vulnerable plaques that remained quiescent. The segments studied by IVUS-VH at baseline were reconstructed using 3D-QCA software and in the obtained geometries blood flow simulation was performed and we estimated the resting Pd/Pa across the vulnerable plaque and the mean ESS values in 3mm sub-segments. A propensity score was built by the baseline plaque characteristics and the hemodynamic indices and its efficacy in detecting nc-MACE-R lesions was examined.

Results

Nc-MACE-R lesions were longer (32.5mm [18.0, 41.6], vs. 19.6mm [12.7, 31.3], p=0.03), had smaller minimum lumen area (MLA) (3.65mm2 [3.26, 4.36] vs. 5.03mm2 [3.98, 6.66], p<0.01), increased plaque burden (PB) (69.4% [63.5, 72.0] vs. 60.8% [53.7, 66.5], p<0.01), were exposed to higher ESS (9.40Pa [6.3, 12.5] vs. 4.1Pa [3.0, 6.9], p<0.01), and exhibited a lower resting Pd/Pa (0.97 [0.95, 0.98] vs. 0.98 [0.97, 0.99], p<0.01]. In multivariable analysis the only independent predictor of nc-MACE-R was the maximum 3mm ESS value (hazard ratio: 1.08 [1.02, 1.16], P=0.016). Lesions exposed to high ESS (>4.95Pa) with a high-risk anatomy (MLA<4mm2and PB>70%) had a higher nc-MACE-R rate (53.8%) than those with a low-risk anatomy exposed to high ESS (31.6%) or those exposed to low ESS that had high (20.0%) or low-risk anatomy (7.1%, P<0.001).

Conclusion

In the present study, 3D-QCA-derived local hemodynamic variables provided useful prognostic information and in combination with lesion anatomy enabled more accurate identification of nc-MACE-R lesions. Further research in a larger number of patients is need to confirm these findings before the conduction of large scale prospective studies that will combine intravascular imaging and 3D-QCA modelling to more accurately detect vulnerable plaques.

Ten-year Medicare budget impact of increased coverage for anti-obesity intervention

Aims: To estimate the long-term budget impact of expanding Medicare coverage of anti-obesity interventions among adults aged 65 and older in the US. Materials and methods: This study analyzed a representative sample of Medicare beneficiaries from the combined 2008-2016 National Health and Nutrition Examination Surveys. Population characteristics, cost and effectiveness of anti-obesity interventions, and the sustainability of weight loss in real-life were modeled to project the budgetary impact on gross Medicare outlay over 10 years. Hypothetical scenarios of 50% and 67% increases in intervention participation above base case were used to model moderate and extensive Medicare coverage expansion of intensive behavior therapy and pharmacotherapy. Results: For each Medicare beneficiary receiving anti-obesity treatment, we estimate Medicare savings of $6,842 and $7,155 over 10 years under moderate and extensive coverage utilization assumptions, respectively. The average cost of intervention is $1,798 and $1,886 per treated participant. Taking the entire Medicare population (treated and untreated) into consideration, the estimated 10-year budget savings per beneficiary are $308 and $339 under moderate and extensive assumptions, respectively. Sensitivity analysis of drug adherence rate and weight-loss efficacy indicated a potential variation of budget savings within 7% and 22% of the base case, respectively. Most of the projected cost savings come from lower utilization of ambulatory services and prescription drugs. Limitations: Due to the scarcity of studies on the efficacy of pharmacotherapy among older adults with obesity, the simulated weight loss and long-term maintenance effects were derived from clinical trial outcomes, in which older adults were mostly excluded from participation. The model did not include potential side-effects from anti-obesity medications and associated costs. Conclusions: This analysis suggests that expanding coverage of anti-obesity interventions to eligible individuals could generate $20-$23 billion budgetary savings to Medicare over 10 years.

Insights into the Role of Employers Supporting Obesity Management in People with Obesity: Results of the National ACTION Study

Lack of both awareness and application of evidence-based principles for obesity care for people with obesity (PwO) limit employers' role in supporting effective obesity management among employees with obesity (EwO). The aim of the ACTION (Awareness, Care, and Treatment In Obesity maNagement) study was to explore the current state of employer wellness programs related to obesity management, evaluate the impact of obesity in the workplace, assess attitudes regarding the role of employers in managing obesity, and identify challenges in implementing workplace wellness programs as perceived by employer representatives (ERs) and EwO. An online survey was conducted among ERs and adult PwO (BMI ≥30 by self-reported height and weight) using a cross-sectional, US-based stratified sample design. There were 153 ER respondents and 3008 adult PwO respondents; 1478 PwO were employed full-time, part-time, or were self-employed. ERs recognize the seriousness of obesity and its negative impact on work productivity; however, wellness programs tend to fall short of addressing specific needs of EwO, evidenced by low participation and success rates reported by EwO. This study highlights the need for programs that address the complexities of obesity and the specific needs of EwO, which currently are inadequately addressed according to EwO.

Persistence of newer anti-obesity medications in a real-world setting

AIMS

Evaluate real-world data on persistence with anti-obesity medications (AOMs) and explore associated patient factors.

METHODS

Truven Health MarketScan® data were analyzed to evaluate utilization of AOMs approved for long-term use between 4/2015 and 3/2016. Kaplan-Meier survival analyses were used to evaluate treatment persistence. A multivariate analysis was performed to identify associations between persistence and relevant factors.

RESULTS

In total, 26,522 adult patients were identified as newly prescribed naltrexone/bupropion (44.0%, mean age 47.1, 80.5% female), lorcaserin (24.8%, 48.5, 79.3%), phentermine/topiramate extended release (15.8%, 46.7, 82.2%) or liraglutide 3.0 mg (15.4%, 46.9, 72.4%). At 6 months, 41.8% of patients were still on liraglutide 3.0 mg, compared to 15.9% lorcaserin (p < 0.001), 18.1% naltrexone/bupropion (p < 0.001), and 27.3% phentermine/topiramate (p < 0.001). After adjusting for baseline factors, patients on liraglutide 3.0 mg had significantly lower risk of discontinuation compared to those on lorcaserin (HR = 0.46, p < 0.0001), naltrexone/bupropion (HR = 0.48, p < 0.0001), and phentermine/topiramate (HR = 0.64, p < 0.0001) over the course of follow-up (mean follow-up duration, 342-427 days). Older age, male gender, having hyperlipidemia, and no prior phentermine use were associated with higher persistence. Over 95% of study patients had commercial insurance.

CONCLUSIONS

In a real-world setting, patients on liraglutide 3.0 mg had the highest persistence rate of the four AOMs studied.

Mixed-methods development of a new patient-reported outcome instrument for chronic low back pain: part 1-the Patient Assessment for Low Back Pain - Symptoms (PAL-S)

We describe the mixed-methods (qualitative and quantitative) development and preliminary validation of the Patient Assessment for Low Back Pain-Symptoms (PAL-S), a patient-reported outcome measure for use in chronic low back pain (cLBP) clinical trials. Qualitative methods (concept elicitation and cognitive interviews) were used to identify and refine symptom concepts and quantitative methods (classical test theory and Rasch measurement theory) were used to evaluate item- and scale-level performance of the measure using an iterative approach. Patients with cLBP participated in concept elicitation interviews (N = 43), cognitive interviews (N = 38), and interview-based assessment of paper-to-electronic mode equivalence (N = 8). A web-based sample of patients with self-reported cLBP participated in quantitative studies to evaluate preliminary (N = 598) and revised (n = 401) drafts and a physician-diagnosed cohort of patients with cLBP (N = 45) participated in preliminary validation of the measure. The PAL-S contained 14 items describing symptoms (overall pain, sharp, prickling, sensitive, tender, radiating, shocking, shooting, burning, squeezing, muscle spasms, throbbing, aching, and stiffness). Item-level performance, scale structure, and scoring seemed to be appropriate. One-week test-retest reproducibility was acceptable (intraclass correlation coefficient 0.81 [95% confidence interval, 0.61-0.91]). Convergent validity was demonstrated with total score and MOS-36 Bodily Pain (Pearson correlation -0.79), Neuropathic Pain Symptom Inventory (0.73), Roland-Morris Disability Questionnaire (0.67), and MOS-36 Physical Functioning (-0.65). Individual item scores and total score discriminated between numeric rating scale tertile groups and painDETECT categories. Respondent interpretation of paper and electronic administration modes was equivalent. The PAL-S has demonstrated content validity and is potentially useful to assess treatment benefit in cLBP clinical trials.

Assessment of Patient-Reported Outcome Instruments to Assess Chronic Low Back Pain

Objective

To identify patient-reported outcome (PRO) instruments that assess chronic low back pain (cLBP) symptoms (specifically pain qualities) and/or impacts for potential use in cLBP clinical trials to demonstrate treatment benefit and support labeling claims.

Design

Literature review of existing PRO measures.

Methods

Publications detailing existing PRO measures for cLBP were identified, reviewed, and summarized. As recommended by the US Food & Drug Administration (FDA) PRO development guidance, standard measurement characteristics were reviewed, including development history, psychometric properties (validity and reliability), ability to detect change, and interpretation of observed changes.

Results

Thirteen instruments were selected and reviewed: Low Back Pain Bothersomeness Scale, Neuropathic Pain Symptom Inventory, PainDETECT, Pain Quality Assessment Scale Revised, Revised Short Form McGill Pain Questionnaire, Low Back Pain Impact Questionnaire, Oswestry Disability Index, Pain Disability Index, Roland-Morris Disability Questionnaire, Brief Pain Inventory and Brief Pain Inventory Short Form, Musculoskeletal Outcomes Data Evaluation and Management System Spine Module, Orebro Musculoskeletal Pain Questionnaire, and the West Haven-Yale Multidimensional Pain Inventory Interference Scale. The instruments varied in the aspects of pain and/or impacts that they assessed, and none of the instruments fulfilled all criteria for use in clinical trials to support labeling claims based on recommendations outlined in the FDA PRO guidance.

Conclusions

There is an unmet need for a validated PRO instrument to evaluate cLBP-related symptoms and impacts for use in clinical trials.

An evolution in the management of fractures of the ankle

Aims

There has been an evolution recently in the management of unstable fractures of the ankle with a trend towards direct fixation of a posterior malleolar fragment. Within these fractures, Haraguchi type 2 fractures extend medially and often cannot be fixed using a standard posterolateral approach. Our aim was to describe the posteromedial approach to address these fractures and to assess its efficacy and safety.

Patients and Methods

We performed a review of 15 patients with a Haraguchi type 2 posterior malleolar fracture which was fixed using a posteromedial approach. Five patients underwent initial temporary spanning external fixation. The outcome was assessed at a median follow-up of 29 months (interquartile range (IQR) 17 to 36) using the Olerud and Molander score and radiographs were assessed for the quality of the reduction.

Results

The median Olerud and Molander score was 72 (IQR 70 to 75), representing a good functional outcome. The reduction was anatomical in ten, with a median step of 1.2 mm (IQR 0.9 to 1.85) in the remaining five patients. One patient had parasthaesiae affecting the medial forefoot, which resolved within three months.

Conclusion

We found that the posteromedial approach to the ankle for the surgical treatment of Haraguchi type 2 posterior malleolar fractures is a safe technique that enables good visualisation and reduction of the individual fracture fragments with promising early outcomes. Cite this article: Bone Joint J 2017;99-B:1496–1501.

Malignant bone tumours of the foot

Introduction Malignant osseous foot tumours are uncommon. Their oncological outcomes have been poorly documented in the literature so far. The aim of this study was to establish the incidence and to evaluate the oncological outcomes of such patients. Methods Our large orthopaedic oncology database was used to review 70 malignant osseous foot tumour patients. Results The age at diagnosis of malignant osseous foot tumours demonstrated a bimodal distribution peaking in the second and eighth decades of life. Overall, 55 primary malignant bone tumours of the foot (79%) were identified. The median duration from onset of symptoms to diagnosis was 52 weeks (interquartile range [IQR]: 17-104). Eight primary tumours (15%) underwent an accidental excision (ie intralesional excision of a malignant bone tumour where some of the tumour has been left behind, also known as a 'whoops procedure') prior to referral to our unit. Forty-six patients (84%) underwent surgery overall and thirteen of these developed recurrence or metastases. Seven of eight patients with a previous accidental excision underwent amputation. Fifteen osseous metastatic foot lesions were identified. The median length of foot symptoms to diagnosis was 24 weeks (IQR: 20-36 weeks). The median time to death following diagnosis of osseous foot metastases was 20.1 months (IQR: 11.3-27.8 months). Conclusions A high index of suspicion and awareness of clinical features of malignant osseous foot tumours are both essential to avoid diagnostic delays. Amputation is associated with a respectable outcome for patients who have undergone previous accidental excisions.

Comparison of Short vs Long Anti-rotation in Treating Trochanteric Fractures

Introduction: A comparative evaluation of the surgical treatment and outcome of patients with pertrochanteric fractures treated with short versus long proximal femoral nail antirotation. Materials and methods: A retrospective review was conducted of patients with pertrochanteric fractures treated between January 2011 and June 2012. In all 80 patients were enrolled in the study, of which 40 were treated with short PFNA and the remaining with long PFNA. Comparative analyses of demographic data, peri-operative outcome and complications were carried out. Results: There was no significant difference noted in the two groups with regards to Arbeitsgemeinschaft fur Osteosynthesefragen (AO) fracture classification, time from injury to surgery, blood transfusion post surgery and hospital stay. The surgical duration for a short PFNA procedure was significantly less (58 minutes) when compared to that of a long PFNA (87 minutes). Similarly intra-operative blood loss was significantly higher in the long PFNA group as compared to the short PFNA. Conclusions: A relatively quicker surgical time of just under an hour , lesser blood loss and better learning curve with trainee surgeons make short PFNA a better implant choice in the treatment of pertrochanteric fractures.

Delayed diagnosis in metastatic lesions of the foot

INTRODUCTION

Pedal acrometastases are a rare complication of disseminated malignancy. To date, there is little in the literature documenting their clinical course.

METHODS

Our large orthopaedic oncology database was used to review the clinical course of symptomatic pedal acrometastases.

RESULTS

A total of 15 cases of pedal acrometastases were identified from 2,595 patients with metastases. The median age at presentation was 64.5 years (range: 14-83 years) and the median length of foot symptoms (predominantly pain and swelling) prior to diagnosis of metastasis was 16 weeks (range: 6-104 weeks). The median survival following diagnosis was 4.6 months (range: 2.3-104.5 months).

CONCLUSIONS

This study suggests that 0.58% of all osseous metastases involve the foot, and that symptoms of foot pain and swelling are often misdiagnosed, leading to delays in treatment. A high index of suspicion is required to diagnose pedal acrometastases early, thereby allowing early treatment so that the patient's quality of life can be maintained prior to death.

Desmoplastic fibroma of bone: A rare bone tumour

We identified thirteen patients with desmoplastic fibroma of bone treated at our institute over a 30 year period. The patients had a mean age of 25.9 years; eight were female. The incidence of desmoplastic fibroma of bone in all patients with benign bone tumours in our population is 0.003%. Surgical treatment ranged from primary amputation to intra-lesional curettage. The incidence of local recurrence was 15.4%. All cases of local recurrence after curettage or marginal excision demonstrated soft-tissue extension of their tumours on initial presentation suggesting that extra-osseous extension requires more radical surgery to control the disease.

This study presents the largest single centre series of desmoplastic fibroma of bone with a mean follow-up time of 8 years. We recommend wide surgical excision, particularly if the lesion can be resected without significant loss of function, as the treatment modality of choice with the lowest rate of recurrence. Patients undergoing intra-lesional or marginal resection need to be advised of the possibility of local recurrence and the need for long-term surveillance.

Distal volar radial plates: how anatomical are they?

BACKGROUND

Fractures of the distal radius are common, with volar locking plates being increasingly used in their treatment. They aim to provide stable internal fixation and are designed to mirror the natural anatomy. Current volar plate designs incorporate a volar cortical angle (VCA) of 25 degrees.

HYPOTHESIS

The aim of this study is to determine whether the VCA in uninjured distal radii corresponds accurately with modern volar plate designs.

MATERIALS AND METHODS

A retrospective radiological analysis utilizing Computed Tomography scans to assess the VCA of 100 distal radii. Each distal radius was subjected to 3 measurements of the VCA in the sagittal plane.

RESULTS

One hundred patients were identified (67 male, 33 female; mean age 37.4 years). The mean VCA was 32.9 degrees (S.D.±5.14 degrees). The VCA in male patients was significantly greater than in females (33.6 vs 31.5 degrees; P=0.04). There was a statistically significant difference between the lateral VCA and medial VCA (32.2 vs 34.3 degrees, P=0.02).

DISCUSSION

Our study clearly demonstrates that the VCA measured in the distal radius is significantly greater than the volar angulation incorporated within modern plate design. Given that the aim of ORIF is to anatomically reconstruct the distal radius, our study highlights that this may not be possible with current plates.

LEVELS OF EVIDENCE

Level IV Retrospective case series.

The surgical management of spinal deformity in children with a Fontan circulation

The management of spinal deformity in children with univentricular cardiac pathology poses significant challenges to the surgical and anaesthetic teams. To date, only posterior instrumented fusion techniques have been used in these children and these are associated with a high rate of complications. We reviewed our experience of both growing rod instrumentation and posterior instrumented fusion in children with a univentricular circulation.

Six children underwent spinal corrective surgery, two with cavopulmonary shunts and four following completion of a Fontan procedure. Three underwent growing rod instrumentation, two had a posterior fusion and one had spinal growth arrest. There were no complications following surgery, and the children undergoing growing rod instrumentation were successfully lengthened. We noted a trend for greater blood loss and haemodynamic instability in those whose surgery was undertaken following completion of a Fontan procedure. At a median follow-up of 87.6 months (interquartile range (IQR) 62.9 to 96.5) the median correction of deformity was 24.2% (64.5° (IQR 46° to 80°) vs 50.5° (IQR 36° to 63°)).

We believe that early surgical intervention with growing rod instrumentation systems allows staged correction of the spinal deformity and reduces the haemodynamic insult to these physiologically compromised children. Due to the haemodynamic changes that occur with the completed Fontan circulation, the initial scoliosis surgery should ideally be undertaken when in the cavopulmonary shunt stage.

Cite this article: Bone Joint J 2014;96-B:94–9.