Statin intensity and postoperative mortality following open repair of intact abdominal aortic aneurysm.

BackgroundThere is a lack of evidence for the association between intensive statin therapy and outcomes following vascular surgery. The aim of this study was to evaluate the association between perioperative statin intensity and in-hospital mortality following open abdominal aortic aneurysm (AAA) repair.MethodsPatients undergoing open AAA repair between 2009 and 2015 were identified from the Premier Healthcare Database. Statin use was classified into low, moderate and high intensity, based on American College of Cardiology/American Heart Association guidelines. Supratherapeutic intensity was defined as doses higher than the recommended guidelines. Multivariable logistic regression analyses were undertaken to assess the association between statin intensity and postoperative major adverse events and in-hospital mortality.ResultsOf 6497 patients undergoing open AAA repair, 3217 (49·5 per cent) received perioperative statin. Statin users were more likely to present with three or more co-morbidities than non-users (26·5 versus 21·8 per cent; P < 0·001). Unadjusted postoperative mortality was significantly lower in statin users (2·6 versus 6·3 per cent; P < 0·001); however, there was no difference in the risk of developing major adverse events. Multivariable analysis showed that statin use was associated with lower odds of death (odds ratio 0·41, 95 per cent c.i. 0·31 to 0·54). Moderate, high and supratherapeutic statin intensities were not associated with lower odds of death or major adverse events compared with low-intensity statin therapy.ConclusionStatin use is associated with lower odds of death in hospital following open AAA repair. High-intensity statins were not associated with lower morbidity or mortality

Failure mechanism of the all-polyethylene glenoid implant

Fixation failure of glenoid components is the main cause of unsuccessful total shoulder arthroplasties. The characteristics of these failures are still not well understood, hence, attempts at improving the implant fixation are somewhat blind and the failure rate remains high. This lack of understanding is largely due to the fundamental problem that direct observations of failure are impossible as the fixation is inherently embedded within the bone. Twenty custom made implants, reflecting various common fixation designs, and a specimen set-up was prepared to enable direct observation of failure when the specimens were exposed to cyclic superior loads during laboratory experiments. Finite element analyses of the laboratory tests were also carried out to explain the observed failure scenarios. All implants, irrespective of the particular fixation design, failed at the implant-cement interface and failure initiated at the inferior part of the component fixation. Finite element analyses indicated that this failure scenario was caused by a weak and brittle implant-cement interface and tensile stresses in the inferior region possibly worsened by a stress raiser effect at the inferior rim. The results of this study indicate that glenoid failure can be delayed or prevented by improving the implant/cement interface strength. Also any design features that reduce the geometrical stress raiser and the inferior tensile stresses in general should delay implant loosening

Risk factors for revision after shoulder arthroplasty: 1,825 shoulder arthroplasties from the Norwegian Arthroplasty Register

Background and purpose Previous studies on shoulder arthroplasty have usually described small patient populations, and few articles have addressed the survival of shoulder implants. We describe the results of shoulder replacement in the Norwegian population (of 4.7 million) during a 12-year period. Trends in the use of shoulder arthroplasty during the study period were also investigated

Statin intensity and postoperative mortality following open repair of intact abdominal aortic aneurysm.

BackgroundThere is a lack of evidence for the association between intensive statin therapy and outcomes following vascular surgery. The aim of this study was to evaluate the association between perioperative statin intensity and in-hospital mortality following open abdominal aortic aneurysm (AAA) repair.MethodsPatients undergoing open AAA repair between 2009 and 2015 were identified from the Premier Healthcare Database. Statin use was classified into low, moderate and high intensity, based on American College of Cardiology/American Heart Association guidelines. Supratherapeutic intensity was defined as doses higher than the recommended guidelines. Multivariable logistic regression analyses were undertaken to assess the association between statin intensity and postoperative major adverse events and in-hospital mortality.ResultsOf 6497 patients undergoing open AAA repair, 3217 (49·5 per cent) received perioperative statin. Statin users were more likely to present with three or more co-morbidities than non-users (26·5 versus 21·8 per cent; P < 0·001). Unadjusted postoperative mortality was significantly lower in statin users (2·6 versus 6·3 per cent; P < 0·001); however, there was no difference in the risk of developing major adverse events. Multivariable analysis showed that statin use was associated with lower odds of death (odds ratio 0·41, 95 per cent c.i. 0·31 to 0·54). Moderate, high and supratherapeutic statin intensities were not associated with lower odds of death or major adverse events compared with low-intensity statin therapy.ConclusionStatin use is associated with lower odds of death in hospital following open AAA repair. High-intensity statins were not associated with lower morbidity or mortality

Reverse Total Shoulder Arthroplasty

Since the introduction of reverse total shoulder arthroplasty (RTSA) in 1987 (in Europe) and 2004 (in the United States), the number of RTSAs performed annually has increased. Although the main indication for RTSA has been rotator cuff tears, indications have expanded to include several shoulder conditions, many of which involve dysfunction of the rotator cuff. RTSA complications have been reported to affect 19% to 68% of patients and include acromial fracture, haematoma, infection, instability, mechanical baseplate failure, neurological injury, periprosthetic fracture and scapular notching. Current controversies in RTSA include optimal baseplate positioning, humeral neck-shaft angle (135° versus 155°), glenosphere placement (medial, lateral or bony increased offset RTSA) and subscapularis repair. Improvements in prosthesis design, surgeon experience and clinical results will need to occur to optimize this treatment for many shoulder conditions. , Cite this article: EFORT Open Rev 2018;3:58–69 DOI: 10.1302/2058-5241.3.170044PubMedScopu

Tightening force and torque of nonlocking screws in a reverse shoulder prosthesis.

BACKGROUND: Reversed shoulder arthroplasty is an accepted treatment for glenohumeral arthritis associated to rotator cuff deficiency. For most reversed shoulder prostheses, the baseplate of the glenoid component is uncemented and its primary stability is provided by a central peg and peripheral screws. Because of the importance of the primary stability for a good osteo-integration of the baseplate, the optimal fixation of the screws is crucial. In particular, the amplitude of the tightening force of the nonlocking screws is clearly associated to this stability. Since this force is unknown, it is currently not accounted for in experimental or numerical analyses. Thus, the primary goal of this work is to measure this tightening force experimentally. In addition, the tightening torque was also measured, to estimate an optimal surgical value. METHODS: An experimental setup with an instrumented baseplate was developed to measure simultaneously the tightening force, tightening torque and screwing angle, of the nonlocking screws of the Aquealis reversed prosthesis. In addition, the amount of bone volume around each screw was measured with a micro-CT. Measurements were performed on 6 human cadaveric scapulae. FINDINGS: A statistically correlated relationship (p<0.05, R=0.83) was obtained between the maximal tightening force and the bone volume. The relationship between the tightening torque and the bone volume was not statistically significant. INTERPRETATION: The experimental relationship presented in this paper can be used in numerical analyses to improve the baseplate fixation in the glenoid bone