Fatal pulmonary embolism following elective total knee replacement using aspirin in multi-modal prophylaxis - A 12year study

BACKGROUND

The National Institute for Health and Clinical Excellence (NICE) has issued guidelines on which thromboprophylaxis regimens are suitable following lower limb arthroplasty. Aspirin is not a recommended agent despite being accepted in orthopaedic guidelines elsewhere. We assessed the incidence of fatal pulmonary embolism (PE) and all-cause mortality following elective primary total knee replacement (TKR) with a standardised multi-modal prophylaxis regime in a large teaching district general hospital.

METHODS

We utilised a prospective audit database to identify those that had died within 42 and 90days postoperatively. Data from April 2000 to 2012 were analysed for 42 and 90day mortality rates. There were a total of 8277 elective primary TKR performed over the 12year period. The multi-modal prophylaxis regimen used unless contraindicated for all patients included 75mg aspirin once daily for four weeks. Case note review ascertained the causes of death. Where a patient had been referred to the coroner, they were contacted for post mortem results.

RESULTS

The mortality rates at 42 and 90days were 0.36 and 0.46%. There was one fatal PE within 42days of surgery (0.01%) who was taking enoxaparin because of aspirin intolerance. Two fatal PE's occurred at 48 and 57days post-operatively (0.02%). The leading cause of death was myocardial infarction (0.13%).

CONCLUSIONS

Fatal PE following elective TKR with a multi-modal prophylaxis regime is a very rare cause of mortality.

The variability in Oxford hip and knee scores in the preoperative period: is there an ideal time to score?

Background All NHS-funded providers are required to collect and report patient-reported outcome measures for hip and knee arthroplasty. Although there are established guidelines for timing such measures following arthroplasty, there are no specific time-points for collection in the preoperative period. The primary aim of this study was to identify whether there was a significant amount of variability in the Oxford hip and knee scores prior to surgical intervention when completed in the outpatient clinic at the time of listing for arthroplasty or when completed at the preoperative assessment clinic. Methods A prospective cohort study of patients listed for primary hip or knee arthroplasty was conducted. Patients were asked to fill in a preoperative Oxford score in the outpatient clinic at the time of listing. They were then invited to fill in the official outcome measures questionnaire at the preoperative assessment clinic. The postoperative Oxford score was then completed when the patient was seen again at their postoperative follow up in clinic. Results Of the total of 109 patients included in this study period, there were 18 (17%) who had a worse score of 4 or more points difference and 43 (39.4%) who had an improvement of 4 or more points difference when the scores were compared between time of listing at the outpatient and at the preoperative assessment clinic. There was a statistically significant difference (P = 0.0054) in the mean Oxford scores. Conclusions The results of our study suggest that there should be standardisation of timing for completing the preoperative patient-reported outcome measures.

The effect of surgical experience on the amount of radiation exposure from fluoroscopy during dynamic hip screw fixation

INTRODUCTION Dynamic hip screw (DHS) fixation for proximal femur fractures is one of the most common procedures in trauma that requires the use of fluoroscopy. Emphasis is often placed on producing the 'perfect picture', which may lead to excessive use of fluoroscopy, without added patient benefit. This study, the largest of its kind, aimed to determine the effect of surgical experience on the amount of radiation exposure from fluoroscopy during DHS fixation. METHODS All hospital admissions for extracapsular proximal femur fractures to our institution between 2007 and 2012 were analysed. Patient demographics, fracture configuration, grade of surgeon and the total radiation dose after fixation were recorded. Analysis of variance was performed to assess differences in radiation levels between different grades of surgeon. RESULTS A total of 1,203 patients with a mean age of 81.3 years (range: 21-105 years) were included in the study. The majority of the fractures were three-part (33.3%), followed by two-part (32.2%), four-part (25.7%) and basicervical (8.9%). Registrars (ST3-ST8) used a significantly higher radiation dose than consultants for all fracture types (p=0.009). When analysed separately by trainee group, the most junior registrars (ST3-ST4) and the most senior registrars (ST7-ST8) were found to use significantly higher radiation levels than consultants (p=0.037 and p<0.001 respectively). CONCLUSIONS The level of surgical experience does influence the amount of radiation exposure from fluoroscopy during DHS fixation. Surgical trainees should not ignore the potential harmful effects of radiation and should be equipped with the knowledge of how to keep the radiation exposure as low as possible.

Abstract P5-08-18: Biomarker (BM) results from MERiDiAN, a double-blind placebo (PLA)-controlled randomized phase 3 trial of 1st-line paclitaxel (PAC) with or without bevacizumab (BEV) for HER2-negative metastatic breast cancer (mBC)

Background: In the MERiDiAN trial, progression-free survival (PFS) was significantly improved with the addition of BEV to 1st-line PAC for mBC in both the ITT population and the subgroup with high baseline plasma (p) vascular endothelial growth factor (VEGF)-A, meeting both co-primary objectives. However, a predictive effect of pVEGF-A was not seen (PFS pVEGF-A-by-treatment interaction p=0.46; secondary endpoint). We report exploratory analyses of additional candidate BMs.

Methods: Patients (pts) with HER2-negative mBC previously untreated with chemotherapy for mBC were randomized to receive PAC (90 mg/m2, days 1, 8 & 15 q4w) combined with either PLA or BEV 10 mg/kg q2w until disease progression or unacceptable toxicity. Plasma, blood and archival tumor sampling was mandatory. The BM-evaluable population (BEP) comprised all ITT pts with a baseline sample for ≥1 BM. Prespecified exploratory BM analyses included: tumor (t) CD31 (marker of microvascular density) and tVEGF-A (molecular target of BEV) by immunohistochemistry; tPAM50 gene expression; and pVEGF receptor (R)-2 by ELISA. For CD31, tVEGF-A and pVEGFR-2 analyses, the BEP was dichotomized using the median of each BM as the cutoff between low and high subgroups. BEV effect on PFS was assessed within these subgroups (unstratified analyses). Similar subgroup analyses were done for each tPAM50 molecular subtype. No adjustment was made for multiplicity of testing as the analyses were exploratory.

Results: The BEP included 467 (97%) of the 481 randomized pts. There was no correlation between CD31, tVEGF-A and pVEGFR-2. Correlations between BMs and PFS are shown below. The hazard ratio (HR) point estimate for BEV effect was lower in luminal B (0.59) than luminal A (0.96) or other smaller tPAM50 subgroups, but 95% CIs overlapped. pVEGFR-2 showed borderline significance for predictive potential using the median (10.2 ng/mL) as the cutoff. In further exploratory analyses using the 1st quartile (Q1; 8.7 ng/mL) as the cutoff, the PFS HR was 1.19 (95% CI 0.75–1.89) in the low (≤Q1) subgroup vs 0.60 (95% CI 0.46–0.79) in the high (&gt;Q1) subgroup (interaction p=0.01).

BMSubgroupNo. of events/ptsMedian PFS, mosPFS HR (95% Wald CI)Interaction p-value  PAC–PLAPAC–BEVPAC–PLAPAC–BEV  tPAM50 (N=421)Luminal A65/10367/10610.911.20.96 (0.68-1.35)Not applicable Luminal B46/6332/569.011.00.59 (0.38-0.93)  HER2 enriched8/119/105.58.30.88 (0.33-2.32)  Basal like29/3727/355.68.50.67 (0.39-1.14) tCD31 (N=410)Low69/9969/1067.610.80.71 (0.51-0.99)0.40 High78/11164/949.211.00.87 (0.62-1.22) tVEGF-A (N=434)Low78/10777/1107.411.00.68 (0.49-0.93)0.23 High76/11165/1069.210.90.89 (0.64-1.24) pVEGFR-2 (N=436)Low70/10773/1119.210.60.90 (0.64-1.25)0.06 High83/10968/1097.912.20.58 (0.42-0.81) 

Conclusions: Of the 4 candidate BMs explored here, potential predictive value was suggested only for pVEGFR-2. Correlations between pVEGFR-2 levels and outcome have been observed in previous retrospective analyses of breast cancer trials. However, similar levels in healthy donors and breast cancer pts, as well as the narrow dynamic range, may limit the utility of pVEGFR-2 as a potential predictive BM for BEV efficacy.

Citation Format: Das Thakur M, Bais C, Estay I, Vaidyanathan R, O'Shaughnessy J, Cameron D, Hubeaux S, Quah C, Miles D. Biomarker (BM) results from MERiDiAN, a double-blind placebo (PLA)-controlled randomized phase 3 trial of 1st-line paclitaxel (PAC) with or without bevacizumab (BEV) for HER2-negative metastatic breast cancer (mBC). [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-08-18.

Obesity and recurrent intervertebral disc prolapse after lumbar microdiscectomy

INTRODUCTION

The primary aim of this study was to investigate the relationship between obesity and recurrent intervertebral disc prolapse (IDP) following lumbar microdiscectomy.

METHODS

A retrospective review of case notes from 2008 to 2012 was conducted for all patients who underwent single level lumbar microdiscectomy performed by a single surgeon. All patients were followed up at two weeks and six weeks following surgery, and given an open appointment for a further six months.

RESULTS

A total of 283 patients were available for analysis: 190 (67%) were in the non-obese group and 93 (32.9%) in the obese group. There was no statistical difference in postoperative infection, dural tear or length of stay between the non-obese and obese groups. Recurrent symptomatic IDP was seen in 27 patients (9.5%) confirmed by magnetic resonance imaging. Nineteen (10.0%) were in the non-obese group and eight (8.6%) in the obese group (p>0.8).

CONCLUSIONS

In our study, obesity was not a predictor of recurrent IDP following lumbar microdiscectomy. Our literature review confirmed that this study reports the largest series to date analysing the relationship between obesity and recurrent IDP following lumbar microdiscectomy in the British population.

Incidence of central nervous system metastases in patients with HER2-positive metastatic breast cancer treated with pertuzumab, trastuzumab, and docetaxel: results from the randomized phase III study CLEOPATRA

BACKGROUND

Results from the phase III trial CLEOPATRA in human epidermal growth factor receptor 2-positive first-line metastatic breast cancer demonstrated significant improvements in progression-free and overall survival with pertuzumab, trastuzumab, and docetaxel over placebo, trastuzumab, and docetaxel. We carried out exploratory analyses of the incidence and time to development of central nervous system (CNS) metastases in patients from CLEOPATRA.

PATIENTS AND METHODS

Patients received pertuzumab/placebo: 840 mg in cycle 1, then 420 mg; trastuzumab: 8 mg/kg in cycle 1, then 6 mg/kg; docetaxel: initiated at 75 mg/m(2). Study drugs were administered i.v. every 3 weeks. The log-rank test was used for between-arm comparisons of time to CNS metastases as first site of disease progression and overall survival in patients with CNS metastases as first site of disease progression. The Kaplan-Meier approach was used to estimate median time to CNS metastases as first site of disease progression and median overall survival.

RESULTS

The incidence of CNS metastases as first site of disease progression was similar between arms; placebo arm: 51 of 406 (12.6%), pertuzumab arm: 55 of 402 (13.7%). Median time to development of CNS metastases as first site of disease progression was 11.9 months in the placebo arm and 15.0 months in the pertuzumab arm; hazard ratio (HR) = 0.58, 95% confidence interval (CI) 0.39-0.85, P = 0.0049. Overall survival in patients who developed CNS metastases as first site of disease progression showed a trend in favor of pertuzumab, trastuzumab, and docetaxel; HR = 0.66, 95% CI 0.39-1.11. Median overall survival was 26.3 versus 34.4 months in the placebo and pertuzumab arms, respectively. Treatment comparison of the survival curves was not statistically significant for the log-rank test (P = 0.1139), but significant for the Wilcoxon test (P = 0.0449).

CONCLUSIONS

While the incidence of CNS metastases was similar between arms, our results suggest that pertuzumab, trastuzumab, and docetaxel delays the onset of CNS disease compared with placebo, trastuzumab, and docetaxel.

CLINICALTRIALSGOV

NCT00567190.

Judet decortication and compression plate fixation of long bone non-union: Is bone graft necessary?

Non-union occurs in 5-10% of all fractures and is caused by a variety of mechanical and biological factors. Stable fixation is essential and many authors recommend the addition of bone graft. Our aim was to evaluate the results of internal fixation using Judet decortication and compression plating for long bone fractures and assess the impact of bone grafting on union rates. Our study group comprised all the patients undergoing compression plate fixation under a single surgeon over a fourteen year period (n=96). AO principles were used and the standard technique involved Judet decortication, compression plating and lag screws. Autologous bone graft was harvested from the iliac crest. The mean age was 45 years and 62% were male. The fracture site was the clavicle (n=20); humerus (n=23); radius and ulna (n=5); femur (n=31) and tibia (n=17). The primary fracture treatment was non-operative (n=41); IM nail (n=22); plate fixation (n=28) and external fixation (n=5). Deep infection was present in 6 cases. Bone graft was used in 40 cases. 91/96 non-unions treated with compression plating healed (95%). Bone grafting was used in all cases for the initial part of the series but its use declined as the surgeon became more confident that the non-unions would heal without the use of bone graft. The case mix and complexity remained constant throughout the study period and the union rate also remained constant. The mean time to radiological union was 6.4 months. In those treated with a compression plate without bone graft the union rate was 94.6% whilst the addition of bone graft resulted in a union rate of 95% (p=0.67). From our study we concluded that the routine use of autologous bone graft may not be necessary and, based upon the union rates observed in this study, a prospective randomised study to evaluate the use of bone graft in non-union surgery would need a sample size of 194,000 to detect a significant increase in union with 80% power. In terms of Numbers Needed Treat (NNT), we would need to give 1179 patients a bone graft to prevent one additional failure of healing.

The influence of socioeconomic status on the incidence, outcome and mortality of fractures of the hip

This is the first study to use the English Indices of Multiple Deprivation 2007, the Government's official measure of multiple deprivation, to analyse the effect of socioeconomic status on the incidence of fractures of the hip and their outcome and mortality. Our sample consisted of all patients admitted to hospital with a fracture of the hip (n = 7511) in Nottingham between 1999 and 2009. The incidence was 1.3 times higher (p = 0.038) in the most deprived populations than in the least deprived; the most deprived suffered a fracture, on average, 1.1 years earlier (82.0 years versus 83.1 years, p < 0.001). The mortality rate proved to be significantly higher in the most deprived population (log-rank test, p = 0.033), who also had a higher number of comorbidities (p = 0.001). This study has shown an increase in the incidence of fracture of the hip in the most deprived population, but no association between socioeconomic status and mortality at 30 days. Preventative programmes aimed at reducing the risk of hip fracture should be targeted towards the more deprived if they are to make a substantial impact.

Patient controlled opioid analgesia versus conventional opioid analgesia for postoperative pain

BACKGROUND

Patients may control postoperative pain by self-administration of intravenous opioids using devices designed for this purpose (patient controlled analgesia or PCA). A 1992 meta-analysis by Ballantyne found a strong patient preference for PCA over conventional analgesia but disclosed no differences in analgesic consumption or length of postoperative hospital stay. Although Ballantyne's meta-analysis found that PCA did have a small but statistically significant benefit upon pain intensity, Walder's review in 2001 did not find a significant differences in pain intensity and pain relief between PCA and conventionally treated groups.

OBJECTIVES

To evaluate the efficacy of PCA versus conventional analgesia (such as a nurse administering an analgesic upon a patient's request) for postoperative pain control.

SEARCH STRATEGY

Randomized controlled trials (RCTs) were identified from the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2004, Issue 3), MEDLINE (1966 to 2004), and EMBASE (1994 to 2004). Additional reports were identified from the reference lists of retrieved papers.

SELECTION CRITERIA

RCTs of PCA versus conventional analgesia that employed pain intensity as a primary or secondary outcome were selected. These trials included RCTs that compared PCA without a continuous background infusion versus conventional parenteral analgesic regimens. Studies that explicitly stated they involved patients with chronic pain were excluded.

DATA COLLECTION AND ANALYSIS

Trials were scored using the Oxford Quality Scale. Meta-analyses were performed of outcomes that included analgesic efficacy assessed by a Visual Analog Scale (VAS), analgesic consumption, patient satisfaction, length of stay and adverse effects. A sufficient number of the retrieved trials reported these parameters to permit meta-analyses.

MAIN RESULTS

Fifty-five studies with 2023 patients receiving PCA and 1838 patients assigned to a control group met inclusion criteria. PCA provided better pain control and greater patient satisfaction than conventional parenteral 'as-needed' analgesia. Patients using PCA consumed higher amounts of opioids than the controls and had a higher incidence of pruritus (itching) but had a similar incidence of other adverse effects. There was no difference in the length of hospital stay.

AUTHORS' CONCLUSIONS

This review provides evidence that PCA is an efficacious alternative to conventional systemic analgesia for postoperative pain control.