Revision of metal-on-metal hip replacements with dual-mobility bearings and acetabular component retention.

Aims: In metal-on-metal (MoM) hip arthroplasties and resurfacings, mechanically induced corrosion can lead to elevated serum metal ions, a local inflammatory response, and formation of pseudotumours, ultimately requiring revision. The size and diametral clearance of anatomical (ADM) and modular (MDM) dual-mobility polyethylene bearings match those of Birmingham hip MoM components. If the acetabular component is satisfactorily positioned, well integrated into the bone, and has no surface damage, this presents the opportunity for revision with exchange of the metal head for ADM/MDM polyethylene bearings without removal of the acetabular component. Methods: Between 2012 and 2020, across two centres, 94 patients underwent revision of Birmingham MoM hip arthroplasties or resurfacings. Mean age was 65.5 years (33 to 87). In 53 patients (56.4%), the acetabular component was retained and dual-mobility bearings were used (DM); in 41 (43.6%) the acetabulum was revised (AR). Patients underwent follow-up of minimum two-years (mean 4.6 (2.1 to 8.5) years). Results: In the DM group, two (3.8%) patients underwent further surgery: one (1.9%) for dislocation and one (1.9%) for infection. In the AR group, four (9.8%) underwent further procedures: two (4.9%) for loosening of the acetabular component and two (4.9%) following dislocations. There were no other dislocations in either group. In the DM group, operating time (68.4 vs 101.5 mins, p < 0.001), postoperative drop in haemoglobin (16.6 vs 27.8 g/L, p < 0.001), and length of stay (1.8 vs 2.4 days, p < 0.001) were significantly lower. There was a significant reduction in serum metal ions postoperatively in both groups (p < 0.001), although there was no difference between groups for this reduction (p = 0.674 (cobalt); p = 0.186 (chromium)). Conclusion: In selected patients with Birmingham MoM hips, where the acetabular component is well-fixed and in a satisfactory position with no surface damage, the metal head can be exchanged for polyethylene ADM/MDM bearings with retention of the acetabular prosthesis. This presents significant benefits, with a shorter procedure and a lower risk of complications.

Birmingham Hip Resurfacing at 25 years.

Aims: The Birmingham Hip Resurfacing (BHR) was introduced in 1997 to address the needs of young active patients using a historically proven large-diameter metal-on-metal (MoM) bearing. A single designer surgeon's consecutive series of 130 patients (144 hips) was previously reported at five and ten years, reporting three and ten failures, respectively. The aim of this study was to extend the follow-up of this original cohort at 25 years. Methods: The study extends the reporting on the first consecutive 144 resurfacing procedures in 130 patients for all indications. All operations were undertaken between August 1997 and May 1998. The mean age at operation was 52.1 years (SD 9.93; 17 to 76), and included 37 female patients (28.5%). Failure was defined as revision of either component for any reason. Kaplan-Meier survival analysis was performed. Routine follow-up with serum metal ion levels, radiographs, and Oxford Hip Scores (OHSs) was undertaken. Results: Overall implant survival was 83.50% (95% confidence interval (CI) 0.79 to 0.90) at 25 years, and the number at risk was 79. Survival in male patients at 25 years was 89.5% (95% CI 0.83 to 0.96) compared to 66.9% for female patients (95% CI 0.51 to 0.83). Ten additional failures occurred in the period of ten to 25 years. These involved an adverse reaction to metal debris in four patients, a periprosthetic femoral neck fracture affecting five patients, and aseptic loosening in one patient. The median chromium levels were 49.50 nmol/l (interquartile range (IQR) 34 to 70), and the median cobalt serum levels were 42 nmol/l (IQR 24.50 to 71.25). The median OHS at last follow-up was 35 (IQR 10 to 48). During the 25-year study period, 29 patients died. Patient survival at 25 years was 75.10% (95% CI 0.67 to 0.83). Conclusion: This study demonstrates that MoM hip resurfacing using the BHR provides a durable alternative to total hip arthroplasty (THA), particularly in younger male patients with osteoarthritis wishing to maintain a high level of function. These results compare favourably to the best results for THAs.

The characteristics and predictors of mortality in periprosthetic fractures around the knee.

Aims: Periprosthetic fractures (PPFs) around the knee are challenging injuries. This study aims to describe the characteristics of knee PPFs and the impact of patient demographics, fracture types, and management modalities on in-hospital mortality. Methods: Using a multicentre study design, independent of registry data, we included adult patients sustaining a PPF around a knee arthroplasty between 1 January 2010 and 31 December 2019. Univariate, then multivariable, logistic regression analyses were performed to study the impact of patient, fracture, and treatment on mortality. Results: Out of a total of 1,667 patients in the PPF study database, 420 patients were included. The in-hospital mortality rate was 6.4%. Multivariable analyses suggested that American Society of Anesthesiologists (ASA) grade, history of peripheral vascular disease (PVD), history of rheumatic disease, fracture around a loose implant, and cerebrovascular accident (CVA) during hospital stay were each independently associated with mortality. Each point increase in ASA grade independently correlated with a four-fold greater mortality risk (odds ratio (OR) 4.1 (95% confidence interval (CI) 1.19 to 14.06); p = 0.026). Patients with PVD have a nine-fold increase in mortality risk (OR 9.1 (95% CI 1.25 to 66.47); p = 0.030) and patients with rheumatic disease have a 6.8-fold increase in mortality risk (OR 6.8 (95% CI 1.32 to 34.68); p = 0.022). Patients with a fracture around a loose implant (Unified Classification System (UCS) B2) have a 20-fold increase in mortality, compared to UCS A1 (OR 20.9 (95% CI 1.61 to 271.38); p = 0.020). Mode of management was not a significant predictor of mortality. Patients managed with revision arthroplasty had a significantly longer length of stay (median 16 days; p = 0.029) and higher rates of return to theatre, compared to patients treated nonoperatively or with fixation. Conclusion: The mortality rate in PPFs around the knee is similar to that for native distal femur and neck of femur fragility fractures. Patients with certain modifiable risk factors should be optimized. A national PPF database and standardized management guidelines are currently required to understand these complex injuries and to improve patient outcomes.

Predictors of mortality in periprosthetic fractures of the hip: Results from the national PPF study.

INTRODUCTION: Periprosthetic fractures (PPFs) around the hip joint are increasing in prevalence. In this collaborative study, we aimed to investigate the impact of patient demographics, fracture characteristics, and modes of management on in-hospital mortality of PPFs involving the hip. METHODS: Using a multi-centre cohort study design, we retrospectively identified adults presenting with a PPF around the hip over a 10-year period. Univariate and multivariable logistic regression analyses were performed to study the independent correlation between patient, fracture, and treatment factors on mortality. RESULTS: A total of 1,109 patients were included. The in-hospital mortality rate was 5.3%. Multivariable analyses suggested that age, male sex, abbreviated mental test score (AMTS), pneumonia, renal failure, history of peripheral vascular disease (PVD) and deep surgical site infection were each independently associated with mortality. Each yearly increase in age independently correlates with a 7% increase in mortality (OR 1.07, p=0.019). The odds of mortality was 2.99 times higher for patients diagnosed with pneumonia during their hospital stay [OR 2.99 (95% CI 1.07-8.37) p=0.037], and 7.25 times higher for patients that developed renal failure during their stay [OR 7.25 (95% CI 1.85-28.47) p=0.005]. Patients with history of PVD have a six-fold greater mortality risk (OR 6.06, p=0.003). Mode of treatment was not a significant predictor of mortality. CONCLUSION: The in-hospital mortality rate of PPFs around the hip exceeds 5%. The fracture subtype and mode of management are not independent predictors of mortality, while patient factors such as age, AMTS, history of PVD, pneumonia, and renal failure can independently predict mortality. Peri-operative optimisation of modifiable risk factors such as lung and kidney function in patients with PPFs around the hip during their hospital stay is of utmost importance.

Characteristics and risk factors of UCS fracture subtypes in periprosthetic fractures around the hip.

Aims: Periprosthetic fractures (PPFs) following hip arthroplasty are complex injuries. This study evaluates patient demographic characteristics, management, outcomes, and risk factors associated with PPF subtypes over a decade. Methods: Using a multicentre collaborative study design, independent of registry data, we identified adults from 29 centres with PPFs around the hip between January 2010 and December 2019. Radiographs were assessed for the Unified Classification System (UCS) grade. Patient and injury characteristics, management, and outcomes were compared between UCS grades. A multinomial logistic regression was performed to estimate relative risk ratios (RRR) of variables on UCS grade. Results: A total of 1,104 patients were included. The majority were female (57.9%; n = 639), ethnically white (88.5%; n = 977), used mobility aids (67%; n = 743), and had a median age of 82 years (interquartile range (IQR) 74 to 87). A total of 77 (7%) had pain prior to the PPF. The most common UCS grade was B2 (33%; n = 368). UCS type D fractures had the longest length of stay (median 19 days (IQR 11 to 26)), highest readmission to hospital (21%; n = 9), and highest rate of discharge to step-down care (52%; n = 23). Multinomial regression suggests that uncemented femoral stems are associated with a reduced risk of UCS C (RRR 0.36 (95% confidence interval (CI) 0.2 to 0.7); p = 0.002) and increased risk of UCS A (RRR 3.3 (95% CI 1.9 to 5.7); p < 0.001), compared to UCS B fracture. Conclusion: The most common PPF type in elderly frail patients is UCS B2. Uncemented stems have a lower risk of UCS C fractures compared to cemented stems. A national PPF database is needed to further identify correlation between implants and fracture subtypes.

The British Orthopaedic Oncology Management (BOOM) audit.

Aims: Most patients with advanced malignancy suffer bone metastases, which pose a significant challenge to orthopaedic services and burden to the health economy. This study aimed to assess adherence to the British Orthopaedic Oncology Society (BOOS)/British Orthopaedic Association (BOA) guidelines on patients with metastatic bone disease (MBD) in the UK. Methods: A prospective, multicentre, national collaborative audit was designed and delivered by a trainee-led collaborative group. Data were collected over three months (1 April 2021 to 30 June 2021) for all patients presenting with MBD. A data collection tool allowed investigators at each hospital to compare practice against guidelines. Data were collated and analyzed centrally to quantify compliance from 84 hospitals in the UK for a total of 1,137 patients who were eligible for inclusion. Results: A total of 846 patients with pelvic and appendicular MBD were analyzed, after excluding those with only spinal metastatic disease. A designated MBD lead was not present in 39% of centres (33/84). Adequate radiographs were not performed in 19% of patients (160/846), and 29% (247/846) did not have an up-to-date CT of thorax, abdomen, and pelvis to stage their disease. Compliance was low obtaining an oncological opinion (69%; 584/846) and prognosis estimations (38%; 223/846). Surgery was performed in 38% of patients (319/846), with the rates of up-to-date radiological investigations and oncology input with prognosis below the expected standard. Of the 25% (215/846) presenting with a solitary metastasis, a tertiary opinion from a MBD centre and biopsy was sought in 60% (130/215). Conclusion: Current practice in the UK does not comply with national guidelines, especially regarding investigations prior to surgery and for patients with solitary metastases. This study highlights the need for investment and improvement in care. The recent publication of British Orthopaedic Association Standards for Trauma (BOAST) defines auditable standards to drive these improvements for this vulnerable patient group.

Can Non-Contrast 3T MRI scans predict the type of labral procedure in hip arthroscopy?

PURPOSE: The study proposed a simple classification system that aimed at predicting the labral procedure during hip arthroscopy using images from unenhanced 3T MRI scans. PATENTS AND METHODS: Forty patients undergoing hip arthroscopy had their MRI scans reviewed pre-operatively by one of two senior radiologists and classified into: type 1: stable labrum with intra-substance degeneration (no labral repair required), type 2: unstable labrum, no intra-substance degeneration (labral repair required), or type 3: unstable labrum with intra-substance degeneration (Labral repair not feasible). Hip arthroscopy is carried out by one of two surgeons and classified accordingly while blinded to the radiologists' assessment. RESULTS: The pre-operative radiological classification managed to predict the labral procedure in 29 cases out of 40 (72.5%). The gamma value was 0.83, and the kappa value was 0.46 denoting moderate agreement. The inter-class correlation coefficient was 0.52 indicating moderate reliability. CONCLUSION: The proposed classification showed a moderate agreement between the radiological findings and arthroscopic findings. As we cannot accurately correlate the MRI findings with the type of surgical management, the surgeon should be prepared for all scenarios of labral procedures. LEVEL OF EVIDENCE: Level IV (case series).

Development and comparison of 1-year survival models in patients with primary bone sarcomas: External validation of a Bayesian belief network model and creation and external validation of a new gradient boosting machine model.

BACKGROUND: Bone sarcomas often present late with advanced stage at diagnosis and an according, varying short-term survival. In 2016, Nandra et al. generated a Bayesian belief network model for 1-year survival in patients with bone sarcomas. The purpose of this study is: (1) to externally validate the prior 1-year Bayesian belief network prediction model for survival in patients with bone sarcomas and (2) to develop a gradient boosting machine model using Nandra et al.'s cohort and evaluate whether the gradient boosting machine model outperforms the Bayesian belief network model when externally validated in an independent Danish population cohort. MATERIAL AND METHODS: The training cohort comprised 3493 patients newly diagnosed with bone sarcoma from the institutional prospectively maintained database at the Royal Orthopaedic Hospital, Birmingham, UK. The validation cohort comprised 771 patients with newly diagnosed bone sarcoma included from the Danish Sarcoma Registry during January 1, 2000-June 22, 2016. We performed area under receiver operator characteristic curve analysis, Brier score and decision curve analysis to evaluate the predictive performance of the models. RESULTS: External validation of the Bayesian belief network 1-year prediction model demonstrated an area under receiver operator characteristic curve of 68% (95% confidence interval, 62%-73%). Area under receiver operator characteristic curve of the gradient boosting machine model demonstrated: 75% (95% confidence interval: 70%-80%), overall model performance by the Brier score was 0.09 (95% confidence interval: 0.077-0.11) and decision curve analysis demonstrated a positive net benefit for threshold probabilities above 0.5. External validation of the developed gradient boosting machine model demonstrated an area under receiver operator characteristic curve of 63% (95% confidence interval: 57%-68%), and the Brier score was 0.14 (95% confidence interval: 0.12-0.16). CONCLUSION: External validation of the 1-year Bayesian belief network survival model yielded a poor outcome based on a Danish population cohort validation. We successfully developed a gradient boosting machine 1-year survival model. The gradient boosting machine did not outperform the Bayesian belief network model based on external validation in a Danish population-based cohort.

How much does a Medical and Healthcare Products Regulatory Agency medical device alert for metal-on-metal hip arthroplasty patients really cost?

BACKGROUND: Many worldwide regulatory authorities recommend regular surveillance of metal-on-metal hip arthroplasty patients given high failure rates. However, concerns have been raised about whether such regular surveillance, which includes asymptomatic patients, is evidence-based and cost-effective. We determined: (1) the cost of implementing the 2015 MHRA surveillance in "at-risk" Birmingham Hip Resurfacing (BHR) patients; and (2) how many asymptomatic hips with adverse reactions to metal debris (ARMD) would have been missed without patient recall. METHODS: All BHR patients eligible for the 2015 MHRA recall (all females, and males with head sizes ⩽46 mm, regardless of symptoms) at one centre were invited for review (hips = 707; patients = 593). All patients were investigated (Oxford Hip Score, radiographs, blood metal ions, and targeted cross-sectional imaging) and managed accordingly. Surveillance costs were calculated using finance department data. RESULTS: The surveillance cost £105,921.79 (range £147.76-£257.50/patient). Radiographs (£39,598) and nurse practitioner time/assistance (£23,618) accounted for 60% of overall costs. 31 hips had ARMD on imaging (12 revised; 19 under surveillance). All revisions were symptomatic. 7 hips with ARMD under surveillance were asymptomatic and remain under regular review. The number needed to treat to avoid missing one asymptomatic ARMD case was 101 patients, representing a cost of £18,041 to avoid one asymptomatic case. CONCLUSIONS: Implementing MHRA surveillance for "at-risk" BHR patients was extremely costly. The risk of asymptomatic ARMD was low with the BHR (1%), suggesting recommended follow-up in asymptomatic patients is not cost efficient. This raises concerns about the increasingly intensive surveillance recommended in the 2017 MHRA guidance for metal-on-metal hip patients.

Mortality risk of surgically managing orthopaedic trauma during the COVID-19 pandemic.

AIMS: It is imperative to understand the risks of operating on urgent cases during the COVID-19 (SARS-Cov-2 virus) pandemic for clinical decision-making and medical resource planning. The primary aim was to determine the mortality risk and associated variables when operating on urgent cases during the COVID-19 pandemic. The secondary objective was to assess differences in the outcome of patients treated between sites treating COVID-19 and a separate surgical site. METHODS: The primary outcome measure was 30-day mortality. Secondary measures included complications of surgery, COVID-19 infection, and length of stay. Multiple variables were assessed for their contribution to the 30-day mortality. In total, 433 patients were included with a mean age of 65 years; 45% were male, and 90% were Caucasian. RESULTS: Overall mortality was 7.6% for all patients and 15.9% for femoral neck fractures. The mortality rate increased from 7.5% to 44.2% in patients with fracture neck of femur and a COVID-19 infection. The COVID-19 rate in the 30-day postoperative period was 11%. COVID-19 infection, age, and Charlson Comorbidity Index were independent risk factor for mortality. CONCLUSION: There was a significant risk of contracting COVID-19 due to being admitted to hospital. Using a site which was not treating COVID-19 respiratory patients for surgery did not identify a difference with respect to mortality, nosocomial COVID-19 infection, or length of stay. The COVID-19 pandemic significantly increases perioperative mortality risk in patients with fractured neck of femora but patients with other injuries were not at increased risk. Cite this article: Bone Jt Open 2021;2(5):330-336.

Efficacy of distal pedicle screw fixation as a caudal foundation in VEPTR growing rod constructs for early onset scoliosis.

PURPOSE: Surgical treatment of Early Onset Scoliosis (EOS) is challenging. Stable and robust foundations are vital. We have assessed a small cohort of patients with a rib-based proximal fixation and a pedicle screw-based distal foundation for a distraction based growing rod system. METHOD: This is a single center study in a tertiary spinal deformity unit with a catchment population of over 6 million. We performed a retrospective radiographic evaluation of 15 patients with EOS treated with Vertical Expandable Titanium Prosthetic Rib (VEPTR) implant between 2007 and 2017. The review of medical records and imaging data was performed to identify growth of the spine and complications with pedicle screws. RESULTS: There were ten male and five female patients with an average age at index surgery of 4yrs 11 months. Mean length of follow-up was 6 yrs 9 months. Serial radiographs revealed improvements in mean Cobb angle of 12 degrees, T1-T12 height of 29 mm and T1-S1 height of 48 mm with no deterioration in distal LIV tilt angle. We report that none of these patients had any complications related to their pedicle screws including cut-out. CONCLUSION: We report a technique which is efficacious and provides a mechanically robust distal fixation for VEPTR lengthening in early onset scoliosis.

A review of informed consent and how it has evolved to protect vulnerable participants in emergency care research.

A vulnerable participant in research lacks capacity to consent or may be exposed to coercion to participate. Capacity may be temporarily impaired due to loss of consciousness, hypoxia, pain and the consumption of alcohol or elicit substances.To advance emergency care, providing life-threatening measures in life-threatening circumstances, vulnerable patients are recruited into research studies. The urgent need for time-critical treatment conflicts with routine informed consent procedures.This article reviews ethical considerations and moral obligations to safeguard these participants and preserve their autonomy.A particular focus is given to research methodology to waive consent, and the role of ethics committees, research audits, research nurses and community engagement.Research on the acutely unwell patient who lacks capacity is possible with well-designed research trials that are led by investigators who are sufficiently trained, engage the community, gain ethical approval to waive consent and continuously audit practice. Cite this article: EFORT Open Rev 2020;5:73-79. DOI: 10.1302/2058-5241.5.180051.

Structuring of Hydrogels across Multiple Length Scales for Biomedical Applications.

The development of new materials for clinical use is limited by an onerous regulatory framework, which means that taking a completely new material into the clinic can make translation economically unfeasible. One way to get around this issue is to structure materials that are already approved by the regulator, such that they exhibit very distinct physical properties and can be used in a broader range of clinical applications. Here, the focus is on the structuring of soft materials at multiple length scales by modifying processing conditions. By applying shear to newly forming materials, it is possible to trigger molecular reorganization of polymer chains, such that they aggregate to form particles and ribbon-like structures. These structures then weakly interact at zero shear forming a solid-like material. The resulting self-healing network is of particular use for a range of different biomedical applications. How these materials are used to allow the delivery of therapeutic entities (cells and proteins) and as a support for additive layer manufacturing of larger-scale tissue constructs is discussed. This technology enables the development of a range of novel materials and structures for tissue augmentation and regeneration.

Innovative use of single-incision internal fixation of distal clavicle fractures augmented with coracoclavicular stabilisation.

INTRODUCTION: The management of displaced fractures of the distal clavicle remains controversial, particularly in younger patients where there is no consensus as to which surgical intervention is best. Each surgical method has unique surgical complications and rates of persistent pain and post-traumatic arthritis. We report an innovative surgical technique using a plate fixation augmented with minimally invasive tension slide coracoclavicular fixation using a cortical tenodesis button (8.5 mm). METHODS: A single-surgeon series, comprising of eleven cases, underwent retrospective review. A low-profile pre-contoured stainless steel plate that combines locking and non-locking options was used. Secondary fixation to the coracoid, through the plate, was achieved under fluoroscopic guidance eliminating the need for arthroscopy or exposure of the coracoid. An 8.5-mm cortical button loaded with a single FiberTape is inserted with fluoroscopic navigation, flipped under the coracoid and fixed to the plate. Patients followed a standardised rehabilitation protocol and clinical review assessing time to union, complications and Oxford Shoulder Scores. RESULTS: The mean age of the patients was 40 years, 82% male. The majority were day-case admissions with a mean follow-up of 18 months. Although a single patient requested plate removal due to lateral prominance, there were no revisions for implant failure and no surgical site infections or neurovascular injuries. All patients were reviewed at a minimum of 17 weeks and were progressing to union. Mean Oxford Shoulder Score was 43 (28-48, SD 6.5). CONCLUSION: We consider this technique ideal for treating Neer type II distal clavicle fractures or fractures that have poor bone quality laterally, in which it can be difficult to achieve adequate screw fixation. The technique benefits from smaller tunnel diameter (3.7-mm spade-tip drill) and button length (8.5 mm). The procedure has a short learning curve and is both safe and time efficient. LEVEL OF EVIDENCE: IV.

Comparing mortality risk of patients with acute hip fractures admitted to a major trauma centre on a weekday or weekend.

Proximal femoral fractures are a major public health concern with estimated annual direct and social costs amounting to £2 billion and average 30-day mortality risk of 7.5%. In response to the recent debate over out-of-hours hospital provision we investigated the 'weekend effect' at a major trauma centre, caring for acute injuries. A single centre, multi-surgeon review of 2060 patients performed. The distribution of patient and treatment variables compared in patients admitted on a weekday or the weekend. Fewer patients met performance indicators during weekend admission, time to surgery (63 vs. 71%) and time to geriatric review (86 vs. 91%). Weekend admission 30-day mortality was marginally lower than weekday (9.7% vs. 10.2%, OR 0.94, 95% CI 0.67 to 1.32, p = 0.7383). Increasing age, female gender, co-morbidities and confusion increased mortality risk. Binary regression analysis including these variables found no significant 'weekend effect'. Despite the unit observing an increasing workload in the last five years, with meticulous workforce planning, senior doctor provisions and careful use of resources, it is possible to provide a seven-day fracture neck of femur service with no variation in thirty-day mortality by the day of admission.

Can a Bayesian Belief Network Be Used to Estimate 1-year Survival in Patients With Bone Sarcomas?

BACKGROUND: Extremity sarcoma has a preponderance to present late with advanced stage at diagnosis. It is important to know why these patients die early from sarcoma and to predict those at high risk. Currently we have mid- to long-term outcome data on which to counsel patients and support treatment decisions, but in contrast to other cancer groups, very little on short-term mortality. Bayesian belief network modeling has been used to develop decision-support tools in various oncologic diagnoses, but to our knowledge, this approach has not been applied to patients with extremity sarcoma. QUESTIONS/PURPOSES: We sought to (1) determine whether a Bayesian belief network could be used to estimate the likelihood of 1-year mortality using receiver operator characteristic analysis; (2) describe the hierarchal relationships between prognostic and outcome variables; and (3) determine whether the model was suitable for clinical use using decision curve analysis. METHODS: We considered all patients treated for primary bone sarcoma between 1970 and 2012, and excluded secondary metastasis, presentation with local recurrence, and benign tumors. The institution's database yielded 3499 patients, of which six (0.2%) were excluded. Data extracted for analysis focused on patient demographics (age, sex), tumor characteristics at diagnosis (size, metastasis, pathologic fracture), survival, and cause of death. A Bayesian belief network generated conditional probabilities of variables and survival outcome at 1 year. A lift analysis determined the hierarchal relationship of variables. Internal validation of 699 test patients (20% dataset) determined model accuracy. Decision curve analysis was performed comparing net benefit (capped at 85.5%) for all threshold probabilities (survival output from model). RESULTS: We successfully generated a Bayesian belief network with five first-degree associates and describe their conditional relationship with survival after the diagnosis of primary bone sarcoma. On internal validation, the resultant model showed good predictive accuracy (area under the curve [AUC] = 0.767; 95% CI, 0.72-0.83). The factors that predict the outcome of interest, 1-year mortality, in order of relative importance are synchronous metastasis (6.4), patient's age (3), tumor size (2.1), histologic grade (1.8), and presentation with a pathologic fracture (1). Patient's sex, tumor location, and inadvertent excision were second-degree associates and not directly related to the outcome of interest. Decision curve analysis shows that clinicians can accurately base treatment decisions on the 1-year model rather than assuming all patients, or no patients, will survive greater than 1 year. For threshold probabilities less than approximately 0.5, the model is no better or no worse than assuming all patients will survive. CONCLUSIONS: We showed that a Bayesian belief network can be used to predict 1-year mortality in patients presenting with a primary malignancy of bone and quantified the primary factors responsible for an increased risk of death. Synchronous metastasis, patient's age, and the size of the tumor had the largest prognostic effect. We believe models such as these can be useful as clinical decision-support tools and, when properly externally validated, provide clinicians and patients with information germane to the treatment of bone sarcomas. CLINICAL RELEVANCE: Bone sarcomas are difficult to treat requiring multidisciplinary input to strategize management. An evidence-based survival prediction can be a powerful adjunctive to clinicians in this scenario. We believe the short-term predictions can be used to evaluate services, with 1-year mortality already being a quality indicator. Mortality predictors also can be incorporated in clinical trials, for example, to identify patients who are least likely to experience the side effects of experimental toxic chemotherapeutic agents.

Periprosthetic humeral fracture after Copeland resurfacing and the role of revision arthroplasty: A report of three cases.

Follow-up series of the Copeland resurfacing hemiarthroplasty have reported few postoperative fractures around the prosthesis. We report three cases of periprosthetic fracture around a Copeland resurfacing arthroplasty. Due to prosthetic loosening and tuberosity comminution, all cases were managed with revision shoulder arthroplasty. All patients had good functional outcome and range of movement on early follow-up.

Lessons learnt from managing an avulsion fracture of the tibial tubercle extending into the tibial physis.

Acute avulsions of the tibial tubercle apophysis are uncommon, with reported incidence of 0.4-2.7% of all physeal injuries. In our case the extent of the injury was not realised at first presentation and initial internal fixation was attempted. At first outpatient follow-up, repeat radiographs indicated the fracture was not reduced and further CT imaging requested. The three-dimensional CT reconstructed images provide considerably more information on the fracture pattern and retrospectively these may have been helpful during the initial procedure. Therefore we would recommend obtaining a preoperative CT scan if extension of the fracture into the tibial physis is suspected. During the second procedure arthroscopy was tried to aid fracture reduction, but visualisation of the anterior articular surface under the anterior horns of the menisci was difficult through the anterior portals with a standard 30° arthroscope and we further recommend having a 70° scope available to ensure optimal visualisation.

Paediatric fracture dislocation of the forearm: an unusual presentation.

Traumatic injuries of the elbow in children pose a diagnostic challenge. They demand precise knowledge of radiographic anatomy, growth characteristics of healthy and injured bones as well as specific fracture dynamics in this age group. Dislocation of the elbow is rare in children, accounting for 3-6% of all childhood elbow injuries. Fractures at the distal humerus and proximal forearm have been extensively discussed in the literature. We describe a unique case of a 4-year-old child presenting with a traumatic radial head fracture and ulnar dislocation not previously reported. Diagnosis and recognition of the injury pattern was fundamental in the successful management of this case. We recommend the use of CT with three-dimensional reconstructions, to fully understand the fracture pattern and dictate subsequent reduction manoeuvres during closed manipulation. Thus preventing open surgical techniques and their associated morbidities.

Innovative use of computer-assisted tomography in the management of an irreducible anterior shoulder dislocation.

Anterior dislocation of the shoulder is a common injury which is often reduced in the emergency department, without specialist orthopedic input. We report a case of an irreducible locked anterior glenohumeral dislocation with impaction of the humeral head onto the antero-inferior glenoid rim and subsequent generation of a Hill-Sachs lesion. To our knowledge, we describe the first reported case of using computer-assisted tomography to generate a sequence of movements to safely disimpact the locked dislocation without causing further iatrogenic injury or a fracture through the humeral articular surface. This novel image-assisted closed reduction technique spared the patient from the morbidity associated with performing open reduction surgery. At 6-month follow-up, the patient reported no re-dislocations, returned to work and had excellent range of motion.