Acute kidney injury (AKI) is a complex disorder for which currently there is no accepted definition. Having a uniform standard for diagnosing and classifying AKI would enhance our ability to manage these patients. Future clinical and translational research in AKI will require collaborative networks of investigators drawn from various disciplines, dissemination of information via multidisciplinary joint conferences and publications, and improved translation of knowledge from pre-clinical research. We describe an initiative to develop uniform standards for defining and classifying AKI and to establish a forum for multidisciplinary interaction to improve care for patients with or at risk for AKI. Members representing key societies in critical care and nephrology along with additional experts in adult and pediatric AKI participated in a two day conference in Amsterdam, The Netherlands, in September 2005 and were assigned to one of three workgroups. Each group's discussions formed the basis for draft recommendations that were later refined and improved during discussion with the larger group. Dissenting opinions were also noted. The final draft recommendations were circulated to all participants and subsequently agreed upon as the consensus recommendations for this report. Participating societies endorsed the recommendations and agreed to help disseminate the results. The term AKI is proposed to represent the entire spectrum of acute renal failure. Diagnostic criteria for AKI are proposed based on acute alterations in serum creatinine or urine output. A staging system for AKI which reflects quantitative changes in serum creatinine and urine output has been developed. We describe the formation of a multidisciplinary collaborative network focused on AKI. We have proposed uniform standards for diagnosing and classifying AKI which will need to be validated in future studies. The Acute Kidney Injury Network offers a mechanism for proceeding with efforts to improve patient outcomes.

Acute Kidney Injury Network: report of an initiative to improve outcomes in acute kidney injury

These guidelines are intended for use by infectious disease specialists, orthopedists, and other healthcare professionals who care for patients with prosthetic joint infection (PJI). They include evidence-based and opinion-based recommendations for the diagnosis and management of patients with PJI treated with debridement and retention of the prosthesis, resection arthroplasty with or without subsequent staged reimplantation, 1-stage reimplantation, and amputation.

/pdf/diagnosis-and-management-of-prosthetic-joint-infection-4ogdeimcv4.pdf

Diagnosis and Management of Prosthetic Joint Infection: Clinical Practice Guidelines by the Infectious Diseases Society of America

Three-dimensional (3D) printing has numerous applications and has gained much interest in the medical world. The constantly improving quality of 3D-printing applications has contributed to their increased use on patients. This paper summarizes the literature on surgical 3D-printing applications used on patients, with a focus on reported clinical and economic outcomes. Three major literature databases were screened for case series (more than three cases described in the same study) and trials of surgical applications of 3D printing in humans. 227 surgical papers were analyzed and summarized using an evidence table. The papers described the use of 3D printing for surgical guides, anatomical models, and custom implants. 3D printing is used in multiple surgical domains, such as orthopedics, maxillofacial surgery, cranial surgery, and spinal surgery. In general, the advantages of 3D-printed parts are said to include reduced surgical time, improved medical outcome, and decreased radiation exposure. The costs of printing and additional scans generally increase the overall cost of the procedure. 3D printing is well integrated in surgical practice and research. Applications vary from anatomical models mainly intended for surgical planning to surgical guides and implants. Our research suggests that there are several advantages to 3D-printed applications, but that further research is needed to determine whether the increased intervention costs can be balanced with the observable advantages of this new technology. There is a need for a formal cost–effectiveness analysis.

/pdf/3d-printing-techniques-in-a-medical-setting-a-systematic-53jv953e7s.pdf

3D-printing techniques in a medical setting: a systematic literature review

https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(14)61798-0.pdf

Periprosthetic joint infection

Objective: To update the practice parameters for the evaluation of adult patients who develop a new fever in the intensive care unit, for the purpose of guiding clinical practice. Participants: A task force of 11 experts in the disciplines related to critical care medicine and infectious diseases was convened from the membership of the Society of Critical Care Medicine and the Infectious Diseases Society of America. Specialties represented included critical care medicine, surgery, internal medicine, infectious diseases, neurology, and laboratory medicine/microbiology. Evidence: The task force members provided personal experience and determined the published literature (MEDLINE articles, textbooks, etc.) from which consensus was obtained. Published literature was reviewed and classified into one of four categories, according to study design and scientific value. Consensus Process: The task force met twice in person, several times by teleconference, and held multiple e-mail discussions during a 2-yr period to identify the pertinent literature and arrive at consensus recommendations. Consideration was given to the relationship between the weight of scientific evidence and the strength of the recommendation. Draft documents were composed and debated by the task force until consensus was reached by nominal group process. Conclusions: The panel concluded that, because fever can have many infectious and noninfectious etiologies, a new fever in a patient in the intensive care unit should trigger a careful clinical assessment rather than automatic orders for laboratory and radiologic tests. A cost-conscious approach to obtaining cultures and imaging studies should be undertaken if indicated after a clinical evaluation. The goal of such an approach is to determine, in a directed manner, whether infection is present so that additional testing can be avoided and therapeutic decisions can be made. (Crit Care Med 2008; 36:1330‐1349)

/pdf/guidelines-for-evaluation-of-new-fever-in-critically-ill-i10hnh3j6p.pdf

Guidelines for evaluation of new fever in critically ill adult patients: 2008 update from the American College of Critical Care Medicine and the Infectious Diseases Society of America.

Background: Glenoid component malposition for anatomic shoulder replacement may result in complications. The purpose of this study was to define the efficacy of a new surgical method to place the glenoid component.

Methods: Thirty-one patients were randomized for glenoid component placement with use of either novel three-dimensional computed tomographic scan planning software combined with patient-specific instrumentation (the glenoid positioning system group), or conventional computed tomographic scan, preoperative planning, and surgical technique, utilizing instruments provided by the implant manufacturer (the standard surgical group). The desired position of the component was determined preoperatively. Postoperatively, a computed tomographic scan was used to define and compare the actual implant location with the preoperative plan.

Results: In the standard surgical group, the average preoperative glenoid retroversion was −11.3° (range, −39° to 17°). In the glenoid positioning system group, the average glenoid retroversion was −14.8° (range, −27° to 7°). When the standard surgical group was compared with the glenoid positioning system group, patient-specific instrumentation technology significantly decreased (p < 0.05) the average deviation of implant position for inclination and medial-lateral offset. Overall, the average deviation in version was 6.9° in the standard surgical group and 4.3° in the glenoid positioning system group. The average deviation in inclination was 11.6° in the standard surgical group and 2.9° in the glenoid positioning system group. The greatest benefit of patient-specific instrumentation was observed in patients with retroversion in excess of 16°; the average deviation was 10° in the standard surgical group and 1.2° in the glenoid positioning system group (p < 0.001). Preoperative planning and patient-specific instrumentation use resulted in a significant improvement in the selection and use of the optimal type of implant and a significant reduction in the frequency of malpositioned glenoid implants.

Conclusions: Novel three-dimensional preoperative planning, coupled with patient and implant-specific instrumentation, allows the surgeon to better define the preoperative pathology, select the optimal implant design and location, and then accurately execute the plan at the time of surgery.

Level of Evidence: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Comparison of patient-specific instruments with standard surgical instruments in determining glenoid component position: a randomized prospective clinical trial.

The purpose of this study was to develop an easily administered tool to preoperatively predict patient discharge disposition after total joint arthroplasty in the United States. Data were collected in a retrospective review of 517 medical charts and analyzed using logistic regression to develop a model for predicting the likelihood that a patient will not be discharged directly home. The resulting regression model was the basis for the nomogram, named the Predicting Location after Arthroplasty Nomogram. This model demonstrated a bootstrap-corrected concordance index of 0.867, excellent calibration, and external validation as demonstrated by a concordance index of 0.861. Preoperative knowledge that a patient is likely to require an extended care facility allows the clinical care team to make appropriate arrangements and avoid potential delays in patient discharge.

Predicting patient discharge disposition after total joint arthroplasty in the United States.

Although the criterion standard for the treatment of prosthetic joint infections (PJIs) is 2-stage revision with interim placement of an antibiotic-loaded spacer, irrigation and debridement with polyethylene exchange offer advantages such as fewer surgeries, reduced potential for intraoperative complications, and lower direct costs. The purpose of this study was to develop a tool to preoperatively predict the probability of successful infection eradication following irrigation and debridement with polyethylene exchange for hip or knee PJIs. A total of 10,411 surgical cases were retrospectively reviewed, and data were collected from 309 charts. Overall, 149 (48.2%) cases failed to eradicate the infection following irrigation and debridement with polyethylene exchange. Univariate analysis identified multiple variables independently associated with reinfection including duration of symptoms, preoperative inflammatory markers, and infecting organism. Logistic regression was used to generate a model (bootstrap-corrected concordance index of 0.645) to predict successful eradication of the infection, which was the basis for a nomogram. Using commonly obtained preoperative variables, the nomogram can be used to predict the probability of infection-free survival at 1, 2, 3, 4, and 5 years. Preoperative knowledge of the probability that a treatment strategy will eradicate a patient's PJI may improve risk assessment.

The Preoperative Prediction of Success Following Irrigation and Debridement With Polyethylene Exchange for Hip and Knee Prosthetic Joint Infections

A method of preoperative planning and provision of patient-specific surgical aids includes creating a virtual model of a native patient tissue. A virtual device is placed into a predetermined device orientation relative to the virtual model (422) of the native patient tissue. At least one predetermined landmark orientation is specified for placement of at least one virtual landmark relative to the native patient tissue. A virtual patient-specific template containing the predetermined landmark orientation and having a landmark guiding feature is generated. At least one virtual patient-specific placement guide configured to interact simultaneously with at least one previously placed virtual landmark and the virtual device when the virtual device is in the predetermined device orientation is generated. A physical patient-specific template is created as a tangible representation of the virtual patient-specific template. A physical patient-specific placement guide is created as a tangible representation of the virtual patient-specific placement guide.

System of preoperative planning and provision of patient-specific surgical aids

Background The purpose of this study was to test the accuracy of a single synovial fluid biomarker, α-defensin, in diagnosing periprosthetic joint infection in revision total hip and revision total knee arthroplasty. Methods A total of 102 patients comprising 116 revision total hip arthroplasty and revision total knee arthroplasty procedures performed between May 2013 and March 2014 were prospectively evaluated. Cases were categorized as infected or notinfected using Musculoskeletal Infection Society criteria. Synovial fluid was obtained and tested for α-defensin using a commercially available kit (Synovasure [CD Diagnostics, Baltimore, Maryland]). Results For first-stage and single-stage revisions, the α-defensin test had a sensitivity of 100% (95% confidence interval [CI], 86%-100%) and a specificity of 98% (95% CI, 90%-100%) with a positive predictive value of 96% (95% CI, 80%-99%) and negative predictive value of 100% (95% CI, 93%-100%). Conclusion A positive α-defensin test result was significantly more sensitive and specific for predicting infection than current diagnostic testing and should be considered when managing periprosthetic joint infection. Level of Evidence: Level III, Study of Diagnostic Test.

Wael K. Barsoum

Papers

Comparison of patient-specific instruments with standard surgical instruments in determining glenoid component position: a randomized prospective clinical trial.

Predicting patient discharge disposition after total joint arthroplasty in the United States.

The Preoperative Prediction of Success Following Irrigation and Debridement With Polyethylene Exchange for Hip and Knee Prosthetic Joint Infections

System of preoperative planning and provision of patient-specific surgical aids

α-Defensin Accuracy to Diagnose Periprosthetic Joint Infection—Best Available Test?