Using Bayesian statistics to estimate the likelihood a new trial will demonstrate the efficacy of a new treatment

Time is Money! Influence on Operating Theater and Sterilization Times of Patient-specific Cutting Guides and Single-use Instrumentation for Total Knee Arthroplasty: A Full Factorial Design of 136 Patients

Background

Patient-specific cutting guides (PSGs) and single-use disposable instrumentation (SUI) have emerged as potential beneficial innovations for total knee arthroplasty. The aim of this study was to evaluate the impact of PSG and SUI for total knee arthroplasty on operating room (OR) and sterilization times.

Methods

A monocentric, prospective, interventional, full factorial design study, including 136 patients, compared patient-specific (PSG, n = 68) to conventional cutting guides (n = 68) and SUI (n = 68) to conventional instrumentation (CVI, n = 68). In the OR, we recorded the number of instrument trays, operating time, and room occupancy time. In the central sterile services department, the total sterilization duration was assessed. The primary outcome was operating time and sterilization duration. Secondary outcomes were difference in the number of trays, Oxford Knee Score, and postoperative mechanical axis.

Results

The median operating time was 80 minutes (Q1-Q3: 73-90) and was significantly increased for SUI compared to that for CVI (+5 minutes, P = .0072). The median sterilization duration was 1261 minutes (Q1-Q3: 934-1603). It was significantly in favor of SUI (936 minutes) over CVI (1565 minutes) (+629 minutes, P < .0001). The total number of instrument trays was 404 for 136 patients: 252 for CVI and 152 for SUI (P < .0001) and 189 for PSG and 215 for conventional cutting guides (P = .0006). There was no significant difference in OKS (P = .86) nor in the postoperative alignment which was between 177° and 183° (75% patients, P = .24).

Conclusions

SUI lowers the number of instrument trays and sterilization duration. PSG is not associated with significant OR or sterilization time reduction. The use of SUI could reduce the risk of noncompliance of instrument trays.

Prevention of Pathological Fracture of the Proximal Femur: A Systematic Review of Surgical and Percutaneous Image-Guided Techniques Used in Interventional Oncology

Background and objectives: Patients suffering from bone metastasis are at high risk for pathological fractures and especially hip fractures. Osteolytic metastases can induce a high morbidity rate (i.e., pain, facture risk, mobility impairment), and operation on them can be difficult in this frail population having a reduced life expectancy. Several medical devices have been investigated for the prevention of these pathological hip fractures. Materials and Methods: To investigate these solutions, a literature review and a meta-analysis of primary studies was performed. Data sources included electronic databases (PubMed, CENTRAL and ClinicalTrials.gov) from 1990 until 1 January 2019. Titles, abstracts and full-text articles were reviewed in order to select only studies evaluating the performance of the studied solution to prevent osteoporotic and/or pathological hip fracture. The main outcomes were the occurrence of hip fracture, pain evaluation (VAS score) and adverse events occurrence (including severe adverse events and deaths). All randomised controlled trials (RCTs) and cohort studies were considered. A Bayesian cumulative meta-analysis was undertaken on the primary studies conducted in patients with bone metastasis. Results: A total of 12 primary studies were identified, all were cohort studies without a control group, and one compared two devices, and were thereafter considered separately. In those 12 samples, 255 patients were included, mean age 61.7 years. After implantation, the cumulative risk of fracture was 5.5% (95% confidence interval, 3.0% to 8.6%), and adverse event occurrence was 17.4% (95%CI, 12.6 to 22.8%), with a median follow-up of 10 months. The posterior probability of a fracture rate below 5% was 40.3%. Conclusions: The literature about medical devices evaluation for preventing hip fractures in metastatic patients is poor and mostly based on studies with a limited level of evidence. However, this systematic review shows promising results in terms of efficacy and tolerance of these devices in patients with bone metastases. This treatment strategy requires further investigations.

CYP2D6 Genotype-guided Metoprolol Therapy in Cardiac Surgery Patients: Rationale and Design of the Pharmacogenetic-guided Metoprolol Management for Postoperative Atrial Fibrillation in Cardiac Surgery (PREEMPTIVE) Pilot Study

OBJECTIVES

The Preemptive Pharmacogenetic-guided Metoprolol Management for Atrial Fibrillation in Cardiac Surgery (PREEMPTIVE) pilot trial aims to use existing institutional resources to develop a process for integrating CYP2D6 pharmacogenetic test results into the patient electronic health record, to develop an evidence-based clinical decision support tool to facilitate CYP2D6 genotype-guided metoprolol administration in the cardiac surgery setting, and to determine the impact of implementing this CYP2D6 genotype-guided integrated approach on the incidence of postoperative atrial fibrillation (AF), provider, and cost outcomes.

DESIGN

One-arm Bayesian adaptive design clinical trial.

SETTING

Single center, university hospital.

PARTICIPANTS

The authors will screen (including CYP2D6 genotype) up to 600 (264 ± 144 expected under the adaptive design) cardiac surgery patients, and enroll up to 200 (88 ± 48 expected) poor, intermediate, and ultrarapid CYP2D6 metabolizers over a period of 2 years at a tertiary academic center.

INTERVENTIONS

All consented and enrolled patients will receive the intervention of CYP2D6 genotype-guided metoprolol management based on CYP2D6 phenotype classified as a poor, intermediate, extensive (normal), or ultrarapid metabolizer.

MEASUREMENTS AND MAIN RESULTS

The primary outcome will be the incidence of postoperative AF. Secondary outcomes relating to rates of CYP2D6 genotype-guided prescription changes, costs, lengths of stay, and implementation metrics also will be investigated.

CONCLUSIONS

The PREEMPTIVE pilot study is the first perioperative pilot trial to provide essential information for the design of a future, large-scale trial comparing CYP2D6 genotype-guided metoprolol management with a nontailored strategy in terms of managing AF. In addition, secondary outcomes regarding implementation, clinical benefit, safety, and cost-effectiveness in patients undergoing cardiac surgery will be examined.

Can a Single-Use and Patient-Specific Instrumentation Be Reliably Used in Primary Total Knee Arthroplasty? A Multicenter Controlled Study

BACKGROUND

The aim of this controlled multicenter study is to evaluate the clinical and radiologic outcomes of primary total knee arthroplasty (TKA) using single-use fully disposable and patient-specific cutting guides (SU) and compare the results to those obtained with traditional patient-specific cutting guides (PSI) vs conventional instrumentation (CI).

METHODS

Seventy consecutive patients had their TKA performed using SU. They were compared to 140 historical patients requiring TKA that were randomized to have the procedure performed using PSI vs CI. The primary measure outcome was mechanical axis as measured on a standing long-leg radiograph using the hip-knee-ankle angle. Secondary outcome measures were Knee Society and Oxford knee scores, operative time, need for postoperative transfusion, and length of hospital stay.

RESULTS

The mean hip-knee-ankle value was 179.8° (standard deviation [SD] 3.1°), 179.2° (SD 2.9°), and 178.3° (SD 2.5°) in the CI, PSI and SU groups, respectively (P = .0082). Outliers were identified in 16 of 65 (24.6%), 15 of 67 (22.4%), and 14 of 70 (20.0%) knees in the CI, PSI, and SU group, respectively (P = .81). There was no significant difference in the clinical results (P = .29 and .19, respectively). Operative time, number of unit transfusion, and length of hospital stay were not significantly different between the 3 groups (P = .45, .31, and 0.98, respectively).

CONCLUSION

The use of an SU in TKA provided similar clinical and radiologic results to those obtained with traditional PSI and CI. The potential economic advantages of single-use instrumentation in primary TKA require further investigation.