Evidence before this study: Acute appendicitis is the most common general surgical emergency in children. Its diagnosis remains challenging and children presenting with acute right iliac fossa (RIF) pain may be admitted for clinical observation or undergo normal appendicectomy (removal of a histologically normal appendix). A search for external validation studies of risk prediction models for acute appendicitis in children was performed on MEDLINE and Web of Science on 12 January 2017 using the search terms ["appendicitis" OR "appendectomy" OR "appendicectomy"] AND ["score" OR "model" OR "nomogram" OR "scoring"]. Studies validating prediction models aimed at differentiating acute appendicitis from all other causes of RIF pain were included. No date restrictions were applied. Validation studies were most commonly performed for the Alvarado, Appendicitis Inflammatory Response Score (AIRS), and Paediatric Appendicitis Score (PAS) models. Most validation studies were based on retrospective, single centre, or small cohorts, and findings regarding model performance were inconsistent. There was no high quality evidence to guide selection of the optimum model and threshold cutoff for identification of low-risk children in the UK and Ireland. Added value of this study: Most children admitted to hospital with RIF pain do not undergo surgery. When children do undergo appendicectomy, removal of a normal appendix (normal appendicectomy) is common, occurring in around 1 in 6 children. The Shera score is able to identify a large low-risk group of children who present with acute RIF pain but do not have acute appendicitis (specificity 44%). This low-risk group has an overall 1 in 30 risk of acute appendicitis and a 1 in 270 risk of perforated appendicitis. The Shera score is unable to achieve a sufficiently high positive predictive value to select a high-risk group who should proceed directly to surgery. Current diagnostic performance of ultrasound is also too poor to select children for surgery. Implications of all the available evidence: Routine pre-operative risk scoring could inform shared decision making by doctors, children, and parents by supporting safe selection of lowrisk patients for ambulatory management, reducing unnecessary admissions and normal appendicectomy. Hospitals should ensure seven-day-a-week availability of ultrasound for medium and high-risk patients. Ultrasound should be performed by operators trained to assess for acute appendicitis in children. For children in whom diagnostic uncertainty remains following ultrasound, magnetic resonance imaging (MRI) or low-dose computed tomography (CT) are second-line investigations.

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Spine surgery has seen considerable advancements over the last 2 decades, particularly in the fields of image-guidance and robotics. These technologies offer the potential to overcome the various technical challenges in spinal surgery, such as physical and mental fatigue, hand tremor, difficulties with manual dexterity, and surgical precision. This review provides an overview of the image-guidance and robotics systems currently available. It will also provide an insight into the emerging technologies in development in the field of spine surgery. Image-guided and robotic-assisted surgical systems have been demonstrated to be safe, accurate, and time-efficient. Future advancements in the field include “augmented reality” systems, which build on these navigation platforms, but are yet to come to market. These developing technologies have considerable potential to improve the field of spine surgery. Further research is required in this area to determine superiority of these developing technologies over conventional techniques before widespread use should be adapted.

Finite element analysis is a computational technique to predict how different materials will react when a range of forces are applied. In the field of orthopedics, this technique has predominantly been used for implant design and testing. As the technology improves, increasing clinical applications are being developed, offering promise in the areas of surgical planning and the opportunity to tailor implants to individual patient characteristics. This article introduces the various preclinical mechanical tests available, as well as providing a brief overview of the finite element analysis technology.