Background. Knee replacement surgery is currently facing three dilemmas: a high dissatisfaction rate; increasing demand with financial constraints; and variation in utilisation. A patient centred approach, usually achieved through shared decision-making, has the potential to help address these dilemmas. However, such an approach requires an understanding of the factors involved in patient decision-making. This is the first study examining decision-making in knee replacements that includes patients at different stages of decision-making – this is critical when considering decision-making as a process. We base our findings in a theoretical model, proposed by Elwyn et al, that highlights the distinction between deliberation and decision-making, and propose modifications to this model specific to knee replacement decision-making. Methods. This study used two focus groups of six patients each and in-depth interviews with 10 patients to examine the factors that affect patient decision-making and their interaction at different points in the decision-making process. A qualitative analysis of themes, based on a constant comparative method, is used to analyse the data. This study was approved by the Dyfed Powys Research Ethics Committee (13/WA/0140). Results. We describe 10 themes that affect patient deliberation over the decision: decision-making style; coping strategies; expectation of outcome; decision-making stress; personal situation; preferred model of care; trust in doctor; sources of information; mental state; and loss of control. We add to Elwyn's model by demonstrating the boundary between deliberation and decision-making is the decision-making threshold. Conclusion. This study provides increased detail on a theoretical model that can be used to describe decision-making, and an understanding of the factors that affect decision-making for patients considering knee replacement. Such an understanding will aid patient centred care, and has particular relevance in developing interventions aimed at delivering information. This is likely to affect the satisfaction rate, demand, and utilisation of knee replacements. Level of evidence. 4

Introduction. Shared decision making (SDM) was introduced in hospital Lillebelt in 2019 and research reports that patients are more satisfied with their treatment, if they play an active role in choosing treatment. A Decision-Helper was constructed and introduced in the treatment for Colles fractures. This study aimed to understand how patients experience shared decision-making (SDM) for an acute illness, and how it affects them when making decisions about the treatment of their distal radius fracture. Method. An exploratory, qualitative study design was performed to understand the patient's experience, during the choice of treatment with SDM. 12 were recruited when they came to their first follow-up 5 days after the injury, in the outpatient clinic. 10 were interviewed; 3 face to face and 7 by telephone. All women aged 57-87 years and all had a displaced Colles fracture, which had been reduced in the Emergency Room. Result. Analyzing the interviews three themes emerged: 1) Acute situation. Patients was positive towards SDM, but found it demanding to participate in. Patients was still in crisis, 5 days after suffering from a fracture. Patients were unable to remember the information given in the ER, regarding the use of the Decision helper. Few had prepared themselves for the consult in the outpatient clinic. 2) Influence on treatment choice. It was unclear to the majority of patients, that cast or surgery, resulted in similar clinical outcomes. 3) The treatment decision was based on personal factors, more than the information received during the consult. Conclusion. Patients wants to be included in the treatment decision. It is important to highlight that booth treatments are equal in clinical outcome, before introducing the Decision-Helper. The doctor´s demeanor is of great importance to the patient's experience. Introducing SDM in the clinical setting requires training and repeated observations, to succeed

Currently implemented accuracy metrics in open-source libraries for segmentation by supervised machine learning are typically one-dimensional scores [1]. While extremely relevant to evaluate applicability in clinics, anatomical location of segmentation errors is often neglected. This study aims to include the three-dimensional (3D) spatial information in the development of a novel framework for segmentation accuracy evaluation and comparison between different methods. Predicted and ground truth (manually segmented) segmentation masks are meshed into 3D surfaces. A template mesh of the same anatomical structure is then registered to all ground truth 3D surfaces. This ensures all surface points on the ground truth meshes to be in the same anatomically homologous order. Next, point-wise surface deviations between the registered ground truth mesh and the meshed segmentation prediction are calculated and allow for color plotting of point-wise descriptive statistics. Statistical parametric mapping includes point-wise false discovery rate (FDR) adjusted p-values (also referred to as q-values). The framework reads volumetric image data containing the segmentation masks of both ground truth and segmentation prediction. 3D color plots containing descriptive statistics (mean absolute value, maximal value,…) on point-wise segmentation errors are rendered. As an example, we compared segmentation results of nnUNet [2], UNet++ [3] and UNETR [4] by visualizing the mean absolute error (surface deviation from ground truth) as a color plot on the 3D model of bone and cartilage of the mean distal femur. A novel framework to evaluate segmentation accuracy is presented. Output includes anatomical information on the segmentation errors, as well as point-wise comparative statistics on different segmentation algorithms. Clearly, this allows for a better informed decision-making process when selecting the best algorithm for a specific clinical application

Introduction. Knee arthroplasty (KA), encompassing Total Knee Replacement (TKR) and Unicompartmental Knee Replacement (UKR), is one of the most common orthopedic procedures, aimed at alleviating severe knee arthritis. Postoperative KA management, especially radiographic imaging, remains a substantial financial burden and lacks standardised protocols for its clinical utility during follow-up. Method. In this retrospective multicentre cohort study, data were analysed from January 2014 to March 2020 for adult patients undergoing primary KA at Imperial NHS Trust. Patients were followed over a five-year period. Four machine learning models were developed to evaluate if post-operative X-ray frequency can predict revision surgery. The best-performing model was used to assess the risk of revision surgery associated with different number of X-rays. Result. The study assessed 289 knees with a 2.4% revision rate. The revision group had more X-rays on average than the primary group. The best performing model was Logistic Regression (LR), which indicated that each additional X-ray raised the revision risk by 52% (p<0.001). Notably, having four or more X-rays was linked to a three-fold increase in risk of revision (OR=3.02; p<0.001). Our results align with the literature that immediate post-operative X-rays have limited utility, making the 2nd post-operative X-ray of highest importance in understanding the patient's trajectory. These insights can enhance management by improving risk stratification for patients at higher revision surgery risk. Despite LR being the best-performing model, it is limited by the dataset's significant class imbalance. Conclusion. X-ray frequency can independently predict revision surgery. This study provides insights that can guide surgeons in evidence-based post-operative decision-making. To use those findings and influence post-operative management, future studies should build on this predictive model by incorporating a more robust dataset, surgical indications, and X-ray findings. This will allow early identification of high-risk patients, allowing for personalised post-operative recommendations

Objectives. Evidence -based medicine (EBM) is designed to inform clinical decision-making within all medical specialties, including orthopaedic surgery. We recently published a pilot survey of the Canadian Orthopaedic Association (COA) membership and demonstrated that the adoption of EBM principles is variable among Canadian orthopaedic surgeons. The objective of this study was to conduct a broader international survey of orthopaedic surgeons to identify characteristics of research studies perceived as being most influential in informing clinical decision-making. Materials and Methods. A 29-question electronic survey was distributed to the readership of an established orthopaedic journal with international readership. The survey aimed to analyse the influence of both extrinsic (journal quality, investigator profiles, etc.) and intrinsic characteristics (study design, sample size, etc.) of research studies in relation to their influence on practice patterns. Results. A total of 353 surgeons completed the survey. Surgeons achieved consensus on the ‘importance’ of three key designs on their practices: randomised controlled trials (94%), meta-analyses (75%) and systematic reviews (66%). The vast majority of respondents support the use of current evidence over historical clinical training; however subjective factors such as journal reputation (72%) and investigator profile (68%) continue to influence clinical decision-making strongly. Conclusion. Although intrinsic factors such as study design and sample size have some influence on clinical decision-making, surgeon respondents are equally influenced by extrinsic factors such as investigator reputation and perceived journal quality. Cite this article: Dr M. Ghert. An international survey to identify the intrinsic and extrinsic factors of research studies most likely to change orthopaedic practice. Bone Joint Res 2016;5:130–136. DOI: 10.1302/2046-3758.54.2000578

Revision knee arthroplasty is a complex procedure with the number and cost of knee revision procedures performed per year expected to rise. Few studies have examined adverse events following revision arthroplasty. The objective of this study was to determine rates of serious adverse events in patients undergoing revision knee arthroplasty with consideration of the indication for revision (urgent versus elective indications) and to compare these with primary arthroplasty and re-revision arthroplasty. Patients undergoing primary knee arthroplasty were identified in the UK Hospital Episode Statistics. Subsequent revision and re-revision arthroplasty procedures in the same patients and same knee were identified. The primary outcome was 90-day mortality and a logistic regression model was used to investigate factors associated with 90-day mortality and secondary adverse outcomes including infection (undergoing surgery), pulmonary embolism, myocardial infarction, stroke. Urgent indications for revision arthroplasty were defined as infection or fracture, and all other indications were included in the elective indications cohort. 939,021 primary knee arthroplasty cases were included of which 40,854 underwent subsequent revision arthroplasty, and 9,100 underwent re-revision arthroplasty. Revision surgery for elective indications was associated with a 90-day rate of mortality of 0.44% (135/30,826; 95% CI 0.37-0.52) which was comparable to primary knee arthroplasty (0.46%; 4,292/939,021; 95% CI 0.44-0.47). Revision arthroplasty for infection, however, was associated with a much higher mortality of 2.04% (184/9037; 95% CI 1.75-2.35; odds ratio [OR] 3.54; 95% CI 2.81-4.46), as was revision for periprosthetic fracture at 5.25% (52/991; 95% CI 3.94-6.82; OR 6.23; 95% CI 4.39-8.85). Higher rates of pulmonary embolism, myocardial infarction, and stroke were also observed in the infection and fracture cohort. These findings highlight the burden of complications associated with revision knee arthroplasty. They will inform shared decision-making for patients considering revision knee arthroplasty for elective indications. Patients presenting with infection of a knee arthroplasty or a periprosthetic fracture are at very high risk of adverse events. It is important that acute hospital services and tertiary referral centres caring for these patients are appropriately supported to ensure appropriate urgency and an anticipation for increased care requirements

Neurological complications in oncological and degenerative spine surgery represent one of the most feared risks of these procedures. Multimodal intraoperative neurophysiological monitoring (IONM) mainly uses methods to detect changes in the patient's neurological status in a timely manner, thus allowing actions that can reverse neurological deficits before they become irreversible. The utopian goal of spinal surgery is the absence of neurological complications while the realistic goal is to optimize the responses to changes in neuromonitoring such that permanent deficits occur less frequently as possible. In 2014, an algorithm was proposed in response to changes in neuromonitoring for deformity corrections in spinal surgery. There are several studies that confirm the positive impact that a checklist has on care. The proposed checklist has been specifically designed for interventions on stable columns which is significantly different from oncological and degenerative surgery. The goal of this project is to provide a checklist for oncological and degenerative spine surgery to improve the quality of care and minimize the risk of neurological deficit through the optimization of clinical decision-making during periods of intraoperative stress or uncertainty. After a literature review on risk factors and recommendations for responding to IONM changes, 3 surveys were administered to 8 surgeons with experience in oncological and degenerative spine surgery from 5 hospitals in Italy. In addition, anesthesiologists, intraoperative neuro-monitoring teams, operating room nurses participated. The members participated in the optimization and final drafting of the checklist. The authors reassessed and modified the checklist during 3 meetings over 9 months, including a clinical validation period using a modified Delphi process. A checklist containing 28 items to be considered in responding to the changes of the IONM was created. The checklist was submitted for inclusion in the new recommendations of the Italian Society of Clinical Neurophysiology (SINC) for intraoperative neurophysiological monitoring. The final checklist represents the consensus of a group of experienced spine surgeons. The checklist includes the most important and high-performance items to consider when responding to IONM changes in patients with an unstable spine. The implementation of this checklist has the potential to improve surgical outcomes and patient safety in the field of spinal surgery

AO Spine Guideline for Using Osteobiologics in Spine Degeneration project is an international collaborative initiative to identify and evaluate evidence on existing use of osteobiologics in spine degenerative diseases. It aims to formulate clinically relevant and internationally applicable guidelines ensuring evidence-based, safe and effective use of osteobiologics. The current focus is the use of osteobiologics in anterior cervical discectomy and fusion surgeries. The guideline development is planned in three phases. Phase 1- Evidence synthesis and Recommendation; Phase 2- Guideline with osteobiologics grading and Validation; Phase 3- Guideline dissemination and Development of a clinical decision support tool. The key questions formulating the guidelines for the use of osteobiologics will be addressed in a series of systematic reviews in Phase 1. The evidence synthesized by the systematic reviews will be assessed by Grading of Recommendations, Assessment, Development and Evaluations (GRADE) methodology, including expert panel discussions to formulate a recommendation. In Phase 2, osteobiologics will be graded based on evidence and the grading will be integrated with the recommendation from Phase 1, and thus formulate a guideline. The guideline will be further validated by prospective clinical studies. In the third phase, dissemination of the proposed guideline and development of a decision support tool is planned. AO-GO aims to bridge an important gap between quality of evidence and use of osteobiologics in spine fusion surgeries. With a holistic approach the guideline aims to facilitate evidence-based, patient-oriented decision-making process in clinical practice, thus stimulating further evidence-based studies regarding osteobiologics usage in spine surgeries

Rotational laxity increases the risk of anterior cruciate ligament (ACL) injuries and residual rotational laxity can result in inferior surgical outcomes and risk of retears. The dynamic rotatory knee stability can be assessed through manual examination, but it is limited to the surgeon's experience and it provides inaccurate measurements, highlighting the need for objective measurement of knee rotational laxity. The objective measurement of knee laxity can help to better identify patients that may benefit from conservative treatment or those that require surgical treatment with or without concomitant extra-articular procedures. We rely in Porto Knee Testing Device (PKTD®) to accurately measure sagittal and rotatory laxity of the knee, either individually or in a combined fashion. The PKTD® is safe and can be used in combination with CT or MRI, which allows to assess both the “anatomy” and the “function” in the same examination. By this way, we may have a total ACL rupture and a stable knee not requiring surgery or, on the other hand, the same injury scenario but with an unstable knee that requires surgical intervention (with or without lateral extra-articular tenodesis). In cases of partial ACL tears, it may be possible to identify some ligamentous fibers that remain functional, where the conservative treatment or augmentation techniques can provide satisfactory results. It can also identify when a posteromedial or posterolateral instability is associated. The PKTD® can also be used to follow-up the laxity results of conservative and surgical procedures and contribute to the decision-making of return to sports

Open lower limb fractures are resource-intensive fractures, accounting for a significant proportion of the workload and cost of orthopaedic trauma units. A recent study has evaluated that the median cost of direct inpatient treatment of open lower-limb fractures in the National Health Service (NHS) is steep, at £19189 per patient. Healthcare providers are expected to be aware of the costs of treatments, although there is very limited dissemination of this information, neither on a national or local level. Older adults (>65 years old) are at an increased risk of the types of high-energy injuries that can result in open lower limb fractures. Generally, there remains a significant lack of literature surrounding the cost of open fracture management, especially in specific patient groups that are disproportionately affected by these fractures. This study has calculated the direct inpatient care costs of older adults with open lower limb fractures. Open lower limb fractures in adult patients over 65 years old treated at Addenbrooke's Hospital of Cambridge University Hospitals NHS Trust were identified over the period of March 2014-March 2019. Isolated fractures of the femur, tibia and fibula over this time period were included. Direct inpatient care costs were calculated using information about the sustained fracture, operative time, implant(s) and theatre kit(s) used, the number of patient bed-days on the orthopaedic ward and critical care unit, and the number of hours of inpatient physiotherapy received. Direct inpatient care costs were compared with the income received by our centre for each of these cases, according to Healthcare Resource Group (HRG) cost codes. Our data was also compared with existing literature on Patient Level Costing (PLC) figures for open lower limb fractures. We extracted data from 58 patients over the age of 65 years treated for open isolated lower limb fractures at Addenbrooke's Hospital, Cambridge University Hospitals NHS Trust, between March 2014 and March 2019. The median cost of inpatient care calculated in this study was £20,398 per patient, resulting in a financial loss to the hospital of £5113 per patient. When the results were disaggregated by sex, the median cost for an open lower limb fracture in a male patient was £20,886 compared to £19,304 in a female patient. Data were also disaggregated by the site of injury, which produced a median cost for an open femur fracture of £23,949, and £24,549 and £15,362 for open tibia and ankle fractures, respectively. The absence of published primary literature and clinical audits on this topic continues to hinder the inclusion of cost-effectiveness as an important factor in clinical decision-making. This study provides valuable insight into the true cost of open lower limb fractures in a key patient population in a Major Trauma Centre in England and highlights the large losses incurred by hospitals in treating these cases. These results support the revision of the remuneration structures in the NHS for the treatment of elderly patients with these injuries

In this edition of Cochrane Corner, two updated reviews have been published in the Cochrane database. The first is a very broad review of rehabilitation strategies for patients with ankle fractures and includes early mobilization, the use of removable splints, and physical therapy techniques for patients treated with and without surgery. The second evaluates interventions for fixing tibial plateau fractures, including fixation techniques and bone graft substitutes.

Background/Purpose of study. The increasing aging of the population will see a growing number of patients presenting for spine surgery with appropriate indications but numerous medical comorbidities. This complicates decision-making, requiring that the likely benefit of surgery (outcome) be carefully weighed up against the potential risk (complications). We assessed the influence of comorbidity on the risks and benefits of spine surgery. Methods. 3′699 patients with degenerative lumbar disorders, undergoing surgery with the goal of pain relief, completed the multidimensional Core Outcome Measures Index (COMI; scored 0–10) before and 12 months after surgery. At 12mo they also rated the global treatment outcome and their satisfaction. Using the Eurospine Spine Tango Registry, surgeons documented surgical details, American Society of Anesthesiologists (ASA) scores and surgical/general complications. Results. 29.8% patients were rated ASA1 (normal healthy), 44.8% ASA2 (mild/moderate systemic disease), 25.0% ASA3 (severe) and 0.4% ASA4 (life-threatening). In going from ASA1 to ASA3 (ASA4 group too small), surgical complications increased significantly from 3.6% to 11.1% and general complications increased from 2.3% to 12.6%; 12-month outcomes showed a corresponding decline, with a good global outcome being reported by 78% ASA1 patients, 76% ASA2, and 68% ASA3. Satisfaction with treatment was 87%, 85%, and 79%, respectively and reduction in COMI, 4.2±2.9, 3.7±3.0, and 3.3±3.0 points, respectively. Conclusion. The negative impact of comorbidity on the outcome of spine surgery has not been well investigated/quantified to date. The ASA grade may be helpful in producing algorithms for decision-making and preoperative counselling regarding the corresponding risks and benefits of surgery. No Conflict of interest. No funding obtained. This abstract has not been previously published in whole or substantial part nor has it been presented previously at a national meeting

Background. A dedicated referral pathway for patients with bony metastases was introduced at Guy's and St Thomas’ Hospitals (GSTT) in 2009. The aim was to facilitate prompt, consultant-led decision-making and intervention for patients at risk of pathological fracture of long bones. Methods. We performed a clinical audit and service evaluation of the referral pathway through retrospective review of referrals over 3.5 years. Results. 75 patients referred from 7 different specialties, (34:41 male:female), mean age 64. 16 different types of primary cancer identified, the most common being breast (22/75). Location of metastasis was most commonly the femur (59/75). 24 patients underwent surgery, with femoral nail the most common procedure (13/24). Patients in the surgery group were younger, with higher Mirel's score, less visceral metastases and survived longer after surgery than patients treated non-operatively. Median referral-clinic time was 10 days and referral-surgery time was 14 days. Conclusions. Our data demonstrate the importance of this service and the growing demand. We have updated trust guidelines and improved our referral process through GSTT's Electronic Patient Record system. We have presented this data at local level to improve awareness and intend to reduce referral-clinical review time and have recently established a multidisciplinary meeting to improve patient outcome. Level of Evidence. 3

Background. We searched -in transverse ultrasound view- the value of the difference (Delta) between -proximal to the tunnel- CSA (a) and -in the tunnel's inlet- CSA (b) for separating normal from abnormal median nerves. Methods. 51 patients –suspicious for CTS- underwent Phalen and Tinnel tests. After that, we used a high frequency ultrasound to measure CSAa, CSAb and Delta CSA in both hands. 33 of our 51 patients did not experience any clinical symptoms at the contralateral hand, so that we could perform a comparative study of normal and pathological median nerves (on the same patients). Then, all of them completed a Q-DASH questionnaire and a visual analogue scale (VAS 100/100) and they carried through with a nerve conduction study (NCS). Results. We found that a CSAb more than 0,010 and a Delta CSA > 0,003 are both very sensitive findings for CTS, but only DeltaCSA has good specificity. Comparing to NCS the Delta CSA>0,003 had no statistical difference in sensitivity, specificity, true negative and true positive results. Furthermore, patients with Delta CSA>0,009 were suffering from heavy CTS according to NCS, Q-DASH and VAS. On the other way, a Delta CSA between 0,003 and 0,006 suggests a mild or moderate CTS. Conclusion. Delta CSA could be the golden standard for the detection of CTS in patients that feel uncomfortable to undergo NCS. We propose a grading scale that distinguish mild or moderate syndromes (where we could try a conservative treatment) from heavy syndromes and help as on decision-making

Background. Radial head fractures are the commonest fractures involving the elbow. The goals of treatment are to restore stability, preserve motion, and maintain the relative length of the radius. Fortunately, most simple uncomplicated fractures can be treated non-operatively. Choosing between fixation and radial head replacement for comminuted fractures remains difficult. Excision of radial head fractures is not an ideal option in unstable elbow injuries. The purpose of this systematic review was to search for and critically appraise articles directly comparing functional outcomes and complications for fixation (open reduction internal fixation, ORIF) versus arthroplasty for comminuted radial head fractures (Mason type 3) in adults. Method. A comprehensive search of Medline, Embase and Cochrane databases using specific search terms and limits was conducted. Strict eligibility criteria were applied to stringently screen resultant articles. Three comparative studies were identified and reviewed. Results. Three comparative studies were identified and reviewed: two studies found significantly better Broberg & Morrey functional scores after replacement compared with ORIF in Mason type 3 fractures. The third study found no significant differences in Mayo functional score or range of motion, but did find that grip strength was better after ORIF. Complication rates were too heterogenous for conclusion. Conclusion. Fixation with good reduction may be attempted in unstable Mason type 3 fractures, and arthroplasty may be considered if this is not possible. Further randomised comparative trials are required to clarify the decision-making between fixation and replacement. Functional outcomes and complications were conflicting in the studies included here. Ideally, treatment decision should take into account elbow stability and degree of comminution

The surgical treatment of spinal deformities and degenerative or oncological vertebral diseases is becoming more common. However, this kind of surgery is complex and associated to a high rate of early and late complications. We retrospectively collected all the major complications observed in the perioperative and post-operative period for surgeries performed at our Division of Spine Surgery in the 2010–2012 period,. 285 surgeries were registered in 2010, 324 in 2011 and 308 in 2012. All the complications observed during the procedure and the follow-up period were recorded and classified according to the type (mechanical complications, neurological complications, infection, hematoma, cerebrospinal fluid fistula, systemic complications, death related to the surgery). In 2010, on 285 surgeries 47 patients (16.5 %) had 69 complications (24.2%): 25.7% for the treatment of oncological diseases, 23% for the treatment of degenerative diseases, 27% for the treatment of pathologies of traumatic origin, 11% for the treatment of spondylodiscitis (infectious diseases). In 2011, on 324 surgeries 35 patients (10.8 %) had 54 complications (16.7%): 16.3% for the treatment of oncological diseases, 16.3% for the treatment of degenerative diseases, 20% for the treatment of pathologies of traumatic origin, 28.6% for the treatment of spondylodiscitis. In 2012, on 308 surgeries, 25 patients (8.1 %) had 36 complications (11.7%): 14.4% for the treatment of oncological diseases, 7.2% for the treatment of degenerative diseases, 16.7% for the treatment of pathologies of traumatic origin, 20% for the treatment of spondylodiscitis. On 917 spinal surgeries performed from January 2010 to December 2012, 159 complications (17.3%) were recorded, with a prevalence of mechanical complications and infections. We are also prospectively collecting complications related to 2013–2015, in order to have a larger amount of data and try to detect potential risk factors to be taken into consideration in the decision-making process for complex spinal surgery

Calcium phosphate cements (CPC) are used as biocompatible and bioactive bone void fillers. Ideally, the mechanical properties of these cements should match those of the surrounding bone. The knowledge of the real mechanical properties of the material is important in the decision-making process regarding possible use of the CPCs in different anatomical sites. Although it is generally recognized that these cements are stiffer and more brittle than desired, there is a limited amount of data about the possible deformation of this class of material before failure. The focus of this study was to determine these properties of injectable CPCs. Two different types of self-setting CPCs were investigated in this study: i) hydroxyapatite (HA), that historically has been the most widely studied CPC; ii) brushite, that recently has attracted attention due to its faster resorption than that of HA in vivo. Specimens of both cement types were prepared by mixing a powder phase with a liquid phase that were left to harden in phosphate buffered saline at 37°C. Once set, the specimens underwent a quasi-static compressive test to determine the compressive strength, the elastic modulus and the maximum deformation of the two materials. The material testing machine was equipped with a digital image correlation system, which allows accurate measurement of material deformation directly on the specimen surface. Brushite was found to be significantly more stiff (+80%) and resistant (+84%) than HA. Similar findings were found for the energy needed to create a first crack on the specimen surface. However, the first crack appeared on the specimen surface at the same low deformation level (∼0.15%) independently of the type of material tested. Complete failure of both materials occurred, on average, before reaching 0.25%. It has been demonstrated that the compressive behaviour of CPCs depends on their composition and porosity [1]. One of the main reasons for the high strength and stiffness of the brushite studied here was its low porosity (∼12%). However, the maximum deformation is not positively affected by this decrease in porosity. In fact, both materials show the same brittle behaviour, i.e. they undergo comparably little deformation before they break. Under these conditions, increasing the compressive strength may not always be beneficial clinically, e.g. in the treatment of vertebral compression fractures, where the high stiffness of the bone cements used has been identified as a risk factor for adjacent-level fractures [2]. However, it is not clear whether a 20-fold higher stiffness than the trabecular bone would give a different clinical outcome than a 10-fold higher stiffness. These high-strength, high-stiffness cements may also be used as a basis for further biomaterial development, e.g. in the creation of macro-porous scaffolds, which is usually challenging due to the commonly low mechanical properties of the base CPC material

This project began as an audit of performance against the 18-week referral to treatment time (RTT) target but became an interesting development in clinical training. The electronic documents and PACS images for 50 consecutive routine GP referrals to an orthopaedic clinic were traced using the UCPN (Unique Care Pathway Number). The average time from referral to 1. st. clinic appointment was 57 days (range 29–117). 16 were discharged at 1. st. visit. 26 were listed for surgery: 20 at the 1. st. clinic, 3 at the 2. nd. clinic, 2 at the 3. rd. clinic, 1 after test results without clinic review. Average time from referral to listing was 68 days (range 28–177). For 25 patients who had surgery, average RTT was 164 days (61–394). 14 patients breached the target. The UCPN allows an overview of the diagnostic work-up for the whole care pathway. Time constraints and less opportunity for continuity of care have hampered effective training in the outpatient clinic. Using the UCPN in this way allows detailed case-based discussions to develop the non-technical surgical skills (NOTSS) of situation awareness and decision-making. In a system where 57 days are typically wasted waiting for a new clinic appointment, clinical reasoning skills must be scalpel sharp to meet the 18-week RTT target. This study hints that better characterising the third of patients discharged and the third directly listed for surgery at the first visit might help with demand management. Better characterising the third of patients needing further tests might allow those test results to be available by the first visit. The next step is to test if, indeed, the UCPN is an effective tool to hone mental dissection