We share our experiences in designing a complete simulator prototype and provide the technological basis to determine whether an immersive medical training environment for vertebroplasty is successful. In our study, the following key research contributions were realised: (1) the effective combination of a virtual reality surgical simulator and a computerised mannequin in designing a novel training setup for medical education, and (2) based on a user-study, the quantitative evaluation through surgical workflow and crisis simulation in proving the face validity of our immersive medical training environment. Medical simulation platforms intend to assist and support surgical trainees by enhancing their skills in a virtual environment. This approach to training is consistent with an important paradigm shift in medical education that has occurred over the past decade. Surgical trainees have traditionally learned interventions on patients under the supervision of a senior physician in what is essentially an apprenticeship model. In addition to exposing patients to some risk, this tends to be a slow and inherently subjective process that lacks objective, quantitative assessment of performance. By proposing our immersive medical simulator we offer the first shared experimental platform for education researchers to design, implement, test, and compare vertebroplasty training methods. We collected feedback from two expert and two novice residents, on improving the teaching paradigm during vertebroplasty. In this way, this limits the risks of complications during the skill acquisition phase that all learners must pass through. The complete simulation environment was evaluated on a 5-pt Likert scale format: (1) strongly disagree, (2) disagree, (3) neither agree nor disagree, (4) agree, and (5) strongly agree. When assessing all aspects of the realism of the simulation environment, specifically on whether it is suitable for the training of technical skills team training, the participating surgeons gave an average score of 4.5. Additionally, we also simulated a crisis simulation. During training, the simulation instructor introduced a visualisation depicting cement extravasation into a perivertebral vein. Furthermore, the physiology of the computerised mannequin was influenced by the instructor simulating a lung embolism by gradually lowering the oxygen saturation from 98% to 80% beginning at a standardised point during the procedure. The simulation was stopped after the communication between the surgeon and the anaesthetist occurred which determined their acknowledgment that an adverse event occurred. The realism of this crisis simulation was ranked with an average score of 4.75. To our knowledge this is the first virtual reality simulator with the capacity to control the introduction of adverse events or complication yielding a wide spectrum of highly adjustable crisis simulation scenarios. Our conclusions validate the importance of incorporating surgical workflow analysis together with virtual reality, human multisensory responses, and the inclusion of real surgical instruments when considering the design of a simulation environment for medical education. The proposed training environment for individuals can be certainly extended to training medical teams

Poly (vinyl alcohol) (PVA) hydrogel with high water content is one of the potential materials for artificial cartilage. In the previous study, the wear behavior of PVA hydrogel prepared by freeze-thawing (FT) method (PVA-FT gel) showed the excellent friction and wear property in simulated biological environment. However, the improvement of mechanical strength and wear resistance would be also needed for clinical application of PVA hydrogel as artificial cartilage. The different kind of physically-crosslinked PVA hydrogels prepared by cast-drying (CD) method (PVA-CD gel) and hybrid method of FT and CD (PVA-CD on FT hybrid gel) were also developed, and these two hydrogels have different mechanical properties and showed low friction compared with PVA-FT gel in saline. In this study, PVA hydrogel prepared by CD and hybrid methods were newly developed and friction and wear behavior of PVA-CD gel and PVA-CD on FT hybrid gel were evaluated in simulated biological environment. A sliding pair of an ellipsoidal reciprocating upper specimen of hydrogel and a flat stationary lower specimen of hydrogel was tested in reciprocating friction test. The thicknesses of PVA-CD gel and PVA-CD on FT hybrid gel were 2.0mm and 1.7mm, respectively. The applied load was 2.94 N. The sliding velocity was 20 mm/s and the total sliding distance was 1.5 km. In this study, solutions that contain hyaluronic acid, phospholipid and proteins were prepared as simulated synovial fluid and used as a lubricant for friction test. Molecular weight of sodium hyaluronate was 9.2×10. 5. L-alpha dipalmitoylphosphatidylcholine (DPPC) was selected as phospholipid constituent and was dispersed in saline as liposome. This liposomal solution was used as a base lubricant. Albumin and gamma-globulin, which are main protein constituents in natural synovial fluid, were used as additives as protein constituents. As shown in Fig.1, PVA-CD gel showed low friction such as below 0.02 at initial state of friction test. However, friction coefficient of PVA-CD gel rapidly increased and reached to about 0.5. In contrast, PVA-CD on FT hybrid gel kept low friction within the friction test. After friction test, many deep scratches were observed on the worn surface of PVA-CD gel (Figs. 2(a)-(c)). In contrast, the original surface structure of PVA-CD on FT hybrid gel almost remained while some scratches were observed (Figs. 2(d)-(f)). These results indicated that PVA-CD gel could show low friction but low wear resistance. The hybridization of FT and CD improved the wear resistance of PVA-CD gel. Therefore, the hybridization of FT and CD method is one of the prospective preparation methods of artificial cartilage with low friction and low wear. It is important to elucidate the mechanism of excellent lubricating property of PVA-CD on FT hybrid gel and develop the highly-functioned artificial hydrogel cartilage with low friction and high wear resistance

Joint assessment through manual physical examination is a fundamental skill that must be acquired by orthopaedic surgeons. These joint assessments allow surgeons to identify soft tissue injuries (e.g. ligament tears) which are critical in identifying appropriate treatment options.

The difficulty in communicating the feeling of different joint conditions and the limited opportunities for practice can make these skills challenging to learn, resulting in reduced treatment effectiveness and increased costs. This research seeks to improve the training of joint assessment with the creation of a haptic joint simulator that can train surgeons with increased effectiveness.

A first of its kind haptic simulator is presented, which incorporates: a newly defined kinetic knee simulation, a haptic device for user interaction, and a haptic control algorithm. The knee model has been specifically created for this application and allows six degree-of-freedom manipulation of the tibia while considering the effects of ten knee ligament bundles. The model has been mathematically formulated to allow for the high update rates necessary for smooth and stable haptic simulation.

Two quantitative assessments were made of the model to confirm its clinical validity. The first was against the widely used OpenSim biomechanical simulation software. Simulations of the model's performance for both anterior-posterior draw tests and varus-valgus rotation tests showed less than 0.7%RMSE for force and 5.5%RMSE for moments. Crucially, the proposed model could generate updated forces in less than 1ms, compared to 188ms for OpenSim. The second validation of the model was against a cadaveric knee that was tested using a validated robotic testing platform. This comparison showed that the model could generate similar force- motion pathways to the cadaveric knee after the model's parameters were scaled to match.

Having demonstrated that it is possible to create a computational knee model that has good conformance to gold-standard knee simulations and cadaveric recordings, while updating at less than 1ms, this research has overcome a major hurdle. The next stage of this research will be to incorporate the knee model into a full haptic simulator and perform skill acquisition trials. Given the effectiveness of past haptic training systems in aiding clinical skills acquisition, this research offers a promising way to improve surgeon training, and therefore also patient diagnosis and treatment.

Aim

The purpose of this study was to report on outcomes after stabilization of large skeletal defects following radical debridement of hip or knee infections and staged reimplantation using segmental antibiotic mega-spacers.

Purpose

Total disc replacement (TDR) devices have been restricted to designs with large, congruent articulations due to the limited wear properties of available materials. TDRs with more natural motion could be designed if materials were available which could resist the higher wear conditions. A novel TriLobe TDR design is self-centering and energetically stable, emulating the natural motion of the intact motion segment, but is not feasible using traditional materials due to small incongruent articulating surfaces. The objective of this study was to compare the wear properties of a medical grade polycrystalline diamond with wear properties of cobalt chrome (CoCr) and ultrahigh molecular weight polyethylene (UHMWPE) in aggressive high wear conditions.

Introduction

Damage development in cemented acetabular replacements has been studied in bovine pelvic bones under long-term physiological¹ loading, albeit dry, conditions, using a specially designed hip simulator². In this work we report further experimental results from testing in wet condition in a new custom designed environmental chamber. Damage was detected and monitored using mCT scanning at regular intervals of the experiments. Two dimensional projections in the axial, sagittal and coronal planes were extracted from the 3D data for fatigue damage identification. The simulated mechanical and biological effects on the initiation and evolution of the damage of cemented acetabular reconstructs were examined and compared with those under dry condition.

Hypochlorous acid (HOCl) is a potent anti-bacterial agent which could reduce periprosthetic joint infection. Early infection complications in joint replacements are often considered to be due to local contamination at the time of surgery and result in a significant socioeconomic cost. Current theatre cleaning procedures produce “clean” operating theatres which still contain bacteria (colony forming units, CFU). Reducing this bacterial load may reduce local contamination at the time of surgery. HOCl is produced naturally in the human neutrophil and has been implicated as the primary agent involved in bacterial killing during this process. In vitro research confirms its efficacy against essentially all clinically relevant bacteria. The recent advent of commercial production of HOCl, delivered as a fog, has resulted in extensive use in the food industry. Reported lack of corrosion and high anti-bacterial potency are seen as two key factors for the use of HOCl in the orthopaedic environment. Prior work by the authors comparing human cell toxicity of HOCl, chlorhexidine and iodine solutions shows favourable results. This study evaluates use of neutral HOCl applied as a dry room fog to decrease bacteria in the operating theatre environment. Using an animal operating theatre as the test site, bacterial swabs were taken from ten 100cm. 2. sample areas before standard cleaning with detergent, after standard cleaning, and again after 60 minutes exposure to HOCl fog. After standard cleaning, 6 of 10 sample sites recorded significant bacterial growth (>10 CFU/100cm. 2. ). After exposure to HOCl fog, growth in all 10 sites was below detection limits (<10 CFU/100cm. 2. ). This was repeated with specific exposure to Staphylococcus aureus and Escherichia coli. We can conclude that HOCl is effective when used as a fogging agent to reduce bacterial loading within an operating theatre environment and as such has significant potential to reduce intraoperative contamination and periprosthetic infection

Complex acetabular reconstruction for oncology and bone loss are challenging for surgeons due to their often hostile biological and mechanical environments. Titrating concentrations of silver ions on implants and alternative modes of delivery allow surgeons to exploit anti-infective properties without compromising bone on growth and thus providing a long-term stable fixation. We present a case series of 12 custom acetabular tri-flange and custom hemipelvis reconstructions (Ossis, Christchurch, New Zealand), with an ultrathin plasma coating of silver particles embedded between layers of siloxane (BioGate HyProtect™, Nuremberg, Germany). At the time of reporting no implant has been revised and no patient has required a hospital admission or debridement for a deep surgical site infection. Routine follow up x-rays were reviewed and found 2 cases with loosening, both at their respective anterior fixation. Radiographs of both cases show remodelling at the ilium indicative of stable fixation posteriorly. Both patients remain asymptomatic. 3 patients were readmitted for dislocations, 1 of whom had 5 dislocations within 3 weeks post-operatively and was immobilised in an abduction brace to address a lack of muscle tone and has not had a revision of their components. Utilising navigation with meticulous implant design and construction; augmented with an ultrathin plasma coating of silver particles embedded between layers of siloxane with controlled and long-term generation of silver ion diffusion has led to outstanding outcomes in this series of 12 custom acetabular and hemipelvis reconstructions. No patients were revised for infection and no patients show signs of failure of bone on growth and incorporation. Hip instability remains a problem in these challenging mechanical environments and we continue to reassess our approach to this multifaceted problem

Using a reverse engineering capability to quantify the factors that control the rigid body mechanics of the wrist, a mathematical forward animation capability and model of wrist motion that allows the carpus to move under its own rules is being developed. This characterises the isometric connections, from which was developed the Stable Central Column Theory of Carpal Mechanics - which incorporates the Law of Rules Based Motion. This work has now advanced to the ability to reapply the extracted rules to allow rules-based rigid body reanimation of an individual wrist. As each wrist is unique, there is a given reality that each reanimation must be based on an individual wrist's unique rules, and the aspiration to create a standard or normal wrist is unrealistic. Using True Life Anatomy (Adelaide, Aust) analysis software, the specific rules (morphology / connectivity / interaction / loading) of individual wrists have been characterised, and then reapplied in a rigid body reanimation environment using Adams (MSC Software, U.S.) software. In the preliminary application of this biomechanics environment, by using the reverse engineering / forward reanimation process, wrist motion can be recreated - based purely on the unique rules, extracted from individual wrists. Instability of the proximal scaphoid was evident in several of the animations, and there was confirmation that the spatial attachment points of the isometric constraints are very exacting. The actual attachment and specific morphology of the carpal bones varied between individual wrists. Using a reverse engineering and then forward reanimation process, we have been able to recreate wrist motion using the rigid body mechanics based on the Law of Rules Based Motion. Further work is required, but the potential to apply “what if” virtual surgery options to an individual injured wrist and more precisely characterise and test solutions to wrist dysfunction are becoming realised

Augmented reality simulators offer opportunities for practice of orthopaedic procedures outside of theatre environments. We developed an augmented reality simulator that allows trainees to practice pinning of paediatric supracondylar humeral fractures (SCHF) in a radiation-free environment at no extra risk to patients. The simulator is composed of a tangible child's elbow model, and simulated fluoroscopy on a tablet device. The treatment of these fractures is likely one of the first procedures involving X-ray guided wire insertion that trainee orthopaedic surgeons will encounter. This study aims to examine the extent of improvement simulator training provides to real-world operating theatre performance. This multi-centre study will involve four cohorts of New Zealand orthopaedic trainees in their SET1 year. Trainees with no simulator exposure in 2019 - 2021 will form the comparator cohort. Trainees in 2022 will receive additional, regular simulator training as the intervention cohort. The comparator cohort's performance in paediatric SCHF surgery will be retrospectively audited using routinely collected operative outcomes and parameters over a six-month period. The performance of the intervention cohorts will be collected in the same way over a comparable period. The data collected for both groups will be used to examine whether additional training with an augmented reality simulator shows improved real-world surgical outcomes compared to traditional surgical training. This protocol has been approved by the University of Otago Health Ethics committee, and the study is due for completion in 2024. This study is the first nation-wide transfer validity study of a surgical simulator in New Zealand. As of September 2022, all trainees in the intervention cohort have been recruited along with eight retrospective trainees via email. We present this protocol to maintain transparency of the prespecified research plans and ensure robust scientific methods. This protocol may also assist other researchers conducting similar studies within small populations

Introduction: The mechanobiology and response of bone formation to strain under physiological loading is well established, however investigation into exceedingly soft scaffolds relative to cancellous bone is limited. In this study we designed and 3D printed mechanically-optimised low-stiffness implants, targeting specific strain ranges inducing bone formation and assessed their biological performance in a pre-clinical in vivo load-bearing tibial tuberosity advancement (TTA) model. The TTA model provides an attractive pre-clinical framework to investigate implant osseointegration within an uneven loading environment due to the dominating patellar tendon force. A knee finite element model from ovine CT data was developed to determine physiological target strains from simulated TTA surgery. We 3D printed low-stiffness Ti wedge osteotomy implants with homogeneous stiffness of 0.8 GPa (Ti1), 0.6 GPa (Ti2) and a locally-optimised design with a 0.3 GPa cortex and soft 0.1 GPa core (Ti3), for implantation in a 12-week ovine tibial advancement osteotomy (9mm). We quantitatively assessed bone fusion, bone area, mineral apposition rate and bone formation rate. Optimised Ti3 implants exhibited evenly high strains throughout, despite uneven wedge osteotomy loading. We demonstrated that higher strains above 3.75%, led to greater bone formation. Histomorphometry showed uniform bone ingrowthin optimised Ti3 compared to homogeneous designs (Ti1 and Ti2), and greater bone-implant contact. The greatest bone formation scores were seen in Ti3, followed by Ti2 and Ti1. Results from our study indicate lower stiffness and higher strain ranges than normally achieved in Ti scaffolds stimulate early bone formation. By accounting for loading environments through rational design, implants can be optimised to improve uniform osseointegration. Design and 3D printing of exceedingly soft titanium orthopaedic implants enhance strain induced bone formation and have significant importance in future implant design for knee, hip arthroplasty and treatment of large load-bearing bone defects

The number of women entering medical school has been steadily increasing over the past two decades; however, the number of women pursuing careers in orthopaedic surgery has not increased at the same rate. One of the suggested reasons for this discrepancy is the perceived incompatibility of having a family while upholding the demands of a surgical career in orthopaedics. A growing body of scientific literature has also outlined the increased rate of infertility and pregnancy complications in women surgeons. The extent to which these factors play a role in the recruitment and retention of women in orthopaedic surgery is unknown. Understanding pregnancy and parenthood in orthopaedic surgery is a critical first step in addressing this issue. A scoping review was conducted to identify literature pertaining to the perceptions and experiences of pregnancy and/or parenthood of women in orthopaedic surgery. Embase, MEDLINE and PsychINFO were searched on June 7th, 2021 with Boolean operators to combine the following terms: orthop?e*, pregnancy, maternity, motherhood, parenthood, parental, and parenting. Studies pertaining to orthopaedic surgery residents, fellows and staff were included. The Arksey and O'Malley framework for scoping studies was followed. Descriptive statistics were used to quantify the included studies while thematic analysis as described by Braun and Clarke was used to analyze the qualitative data. A total of 17 studies from 2006 to 2021 met inclusion criteria. Over half of the available research was conducted within the last two years (n=9, 53%). The majority of studies were conducted in the United States (n=15, 88%) and the United Kingdom (n=2, 12%). The most commonly used study design was survey-based research (n=13, 76%), followed by review studies (n=3, 18%), and case series (n=1, 6%). Thematic analysis revealed five key themes contributing to the women's experiences of pregnancy and/or parenthood in orthopaedics: (1) women are subtly or blatantly discouraged from becoming pregnant by their colleagues and superiors, (2) women delay childbearing to preserve their professional reputation, (3) there are higher rates of infertility and preterm labor in orthopaedic surgeons than in the general population, (4) the orthopaedic work environment can be hazardous and challenging for the pregnant woman, but accommodations are possible to mitigate risks, and (5) overall, there is limited support for pregnant and/or parenting women in orthopaedics throughout their career. The first woman to be board-certified in orthopaedic surgery in the United States was Ruth Jackson in 1937. Eighty-four years later, orthopaedic surgery has the lowest number of women of the surgical specialties. The barriers related to pregnancy and/or parenthood during a woman's career in orthopaedics may be one cause. This study identified five themes related to pregnancy and parenthood that warrant further investigation. Qualitative research approaches can be used to elucidate the details of women's experiences and to provide suggestions for structural changes in the orthopaedic work environment

Introduction. Circular frame fixation has become a cornerstone of non-union and deformity management since its inception in the 1950s. As a consequence of modularity and heterogenous patient and injury factors, the prediction of the mechanobiological environment within a defect is subject to wide variations in practice. Given these wide range of confounding variables, clinical and cadaveric experimentation is close to impossible and frame constructs are based upon clinician experience. The Finite Element Analysis (FEA) method provides a powerful tool to numerically analyse mechanics. This work aims to develop an FEA model of a tibial defect and predict the mechanical response within the construct. Materials and Methods. The geometry of a tibia was acquired via CT and a series of bone defects were digitally created in the tibial diaphysis. A 4-ring, 10-wire Ilizarov fixator was constructed using 180mm stainless steel rings and 1.8mm stainless steel wires tensioned to 1200N. An axial load (800N) was applied to simulate single leg stance of an 80kg patient. The magnitude of displacement was measured for defects with varying sizes (5–40mm). A numerical analysis was performed in large-strain regime using open-source FEA library (MoFEM). Results. Defect size did not effect displacement, but significantly influenced strain. Measured displacements were 5.72–5.78mm, however strain ranged from 14.5–100%. Moreover, it was found that bone material properties also have no significant impact on the results. Conclusions. Accounting for FEA assumptions, this model predicted a strain environment which was above expected favourable range for bone healing. The addition of graft within the environment is likely to change the mechanobiological environment which warrants further investigation. We plan to develop this model to answer further research questions in the limb reconstruction discipline and validate its accuracy with mechanical data. We believe the presented approach can be a useful tool for investigating the performance circular frames

Abstract. Background. During COVID-19 pandemic, there has been worldwide cancellation of elective surgeries to protect patients from nosocomial transmission and peri-operative complications. With unfolding situation, there is definite need for exit strategy to reinstate elective services. Therefore, more literature evidence supporting exit plan to elective surgical services is imperative to adopt a safe working principle. This study aims to provide evidence for safe elective surgical practice during pandemic. Methods. This single centre, prospective, observational study included adult patients who were admitted and underwent elective surgical procedures in the trust's COVID-Free environment at Birmingham Treatment Centre between 19th May and 14th July’2020. Data collected on demographic parameters, peri-operative variables, surgical specialities, COVID-19 RT-PCR testing results, post-operative complications and mortality. The study also highlighted the protocols it followed for the elective services during pandemic. Results. 303 patients were included with mean age of 49.9 years (SD 16.5) comprising of 59% (178) female and 41% (125) male. They were classified according to American Society of Anaesthesiologist Grade, different surgical specialities and types of anaesthesia used. 96% patients were discharged on the same day. 100% compliance to pre-operative COVID-19 testing was maintained. There was no 30-day mortality or major respiratory complications. Conclusion. Careful patient selection, simultaneous involvement of the pre-assessment and anaesthetic team, strict adherence to peri-operative protocols and delivering vigilant post-operative care for COVID-19 infection can help providing safe elective surgical services if the community transmission under reasonable control. However, it is particularly important to maintain COVID-free safe environment for such procedures

A method is proposed to assess risk parameters of anterior cruciate ligament (ACL) injury using human pose estimation (HPE) and a single stereo depth camera. Detectron2 is used to identify key points of a subject performing a single leg jump test. This allows dynamic pivot of the knee to be assessed during landing using four risk parameters: knee valgus, knee translation in the coronal plane, pelvic tilt, and head-ankle alignment (body sway). Results show the model has an accuracy of 7° in angular measurements and 38 mm in linear measurements. Compared to previous studies, which only consider front-on analysis, this method has partially reduced accuracy in linear measurements and half the accuracy in angular measurements. Despite this, coupling information from multiple risk parameters reduces the accuracy required on any one parameter and the use of a single depth camera enables reliable analysis at a subject orientation of ±45° relative to the camera. These factors create a novel solution, proposing the ability for broad evaluation of ACL risk parameters in environments outside a testing laboratory, which has not been done before

3D printing and Bioprinting technologies are becoming increasingly popular in surgery to provide a solution for the regeneration of healthy tissues. The aim of our project is the regeneration of articular cartilage via bioprinting means, to manage isolated chondral defects. Chrondrogenic hydrogel (chondrogel: GelMa + TGF-b3 and BMP6) was prepared and sterilised in our lab following our standard protocols. Human adipose-derived mesenchymal stem cells were harvested from the infrapatellar fat pad of patients undergoing total knee joint replacements and incorporated in the hydrogel according to our published protocols. The chondrogenic properties of the chondrogel have been tested (histology, immunohistochemistry, PCR, immunofluorescence, gene analysis and 2. nd. harmonic generation microscopy) in vitro and in an ex-vivo model of human articular defect and compared with standard culture systems where the growth factors are added to the media at repeated intervals. The in-vitro analysis showed that the formation of hyaline cartilage pellet was comparable between the two strategies, with a similar metabolic activity of the cells. These results have been confirmed in the ex-vivo model: hyaline-like cartilage was observed within the chondral defect in both the chondrogel group and the control group after 28 days in culture. The use of bioprinting techniques in vivo requires the ability of stem cells to access growth factors directly in the environment they are in, as opposed to in vitro techniques where these factors are provided externally at recurrent intervals. This study showed the successful strategy of incorporating chondrogenic growth factors for the formation of hyaline-like cartilage in vitro and in an ex-vivo model of chondral loss. The incorporation of chondrogenic growth factors in a hydrogel is a possible strategy for articular cartilage regeneration

In reverse shoulder arthroplasty (RSA), a high complication rate is noted in the international literature (24.7%), and limited local literature is available. The complications in our developing health system, with high HIV, tuberculosis and metabolic syndrome prevalence may be different from that in developed health systems where the literature largely emanates from. The aim of this study is to describe the complications and complication rate following RSA in a South African cohort. An analytical, cross-sectional study was done where all patients’ who received RSA over an 11 year period at a tertiary hospital were evaluated. One-hundred-and-twenty-six primary RSA patients met the inclusion criteria and a detailed retrospective evaluation of their demographics, clinical variables and complication associated with their shoulder arthroplasty were assessed. All fracture, revision and tumour resection arthroplasties were excluded, and a minimum of 6 months follow up was required. A primary RSA complication rate of 19.0% (24/126) was noted, with the most complications occurring after 90 days at 54.2% (13/24). Instability was the predominant delayed complication at 61.5% (8/13) and sepsis being the most common in the early days at 45.5% (5/11). Haematoma formation, hardware failure and axillary nerve injury were also noted at 4.2% each (1/24). Keeping in mind the immense difference in socioeconomical status and patient demographics in a third world country the RSA complication rate in this study correlates with the known international consensus. This also proves that RSA is still a suitable option for rotator cuff arthropathy and glenohumeral osteoarthritis even in an economically constrained environment like South Africa

Osteoarticular infections (OAI) are a common cause of morbidity in children, and as opposed to adults is usually caused by haematogenous spread. The bacteriology of OAI in children is not well described in the South African context, therefore this study was designed to determine the bacteriology of OAI in our population. All patients that underwent surgery for the treatment of OAI over a 3-year period were identified and those with positive cultures where organisms were identified from tissue, pus, fluid or blood were included. Duplicate cultures from the same patient were excluded if the organism and antibiotic susceptibility profile was the same. Patients were categorised according to age and class of infection (Septic arthritis, acute osteomyelitis, fracture related infection, post-operative sepsis and chronic osteomyelitis) and organisms were stratified according to these categories. We identified 132 organisms from 123 samples collected from 86 patients. Most cultured organisms were from children older than 3-years with acute haematogenous septic arthritis, osteomyelitis, or both. Methicillin sensitive Staphylococcus aureus accounted for 56% (74/132) of organisms cultured. There were no cases of MRSA. The Enterobacterales accounted for 17% (22/132) of organisms cultured, mostly in the fracture related and post-operative infection groups. Of these, 6 each were extended spectrum B-lactamase producers and AmpC producers. There were no carbapenemase producing Enterobacterales. Kingella kingae was not isolated in any patient. Methicillin sensitive S. aureus is the most common infecting organism in paediatric OAI and an anti-staphylococcal penicillin such as cloxacillin or flucloxacillin is the most appropriate empiric treatment for haematogenous OAI in our environment. In fracture related or post-operative infections, Enterobacterales were more frequently cultured, and treatment should be guided by culture and susceptibility results

Introduction. The management of fracture-related infection has undergone radical progress following the development of international guidelines. However, there is limited consideration to the realities of healthcare in low-resource environments due to a lack of available evidence in the literature from these settings. Initial antimicrobial suppression to support fracture union is frequently used in low- and middle-income countries despite the lack of published clinical evidence to support its practice. This study aimed to evaluate the outcomes following initial antimicrobial suppression to support fracture union in the management of fracture-related infection. Materials & Methods. A retrospective review of consecutive patients treated with initial antimicrobial suppression to support fracture healing followed by definitive eradication surgery to manage fracture-related infections following intramedullary fixation was performed. Indications for this approach were; a soft tissue envelope not requiring reconstructive surgery, radiographic evidence of stable fixation with adequate alignment, and progression towards fracture union. Results. This approach was associated with successful treatment in 51/55 (93%) patients. Fracture union was achieved in 52/55 (95%) patients with antimicrobial suppression alone. Remission of infection was achieved in 54/55 (98%) patients following definitive infection eradication surgery. Following antibiotic suppression, 6/46 (13%) pathogens isolated from intra-operative samples demonstrated multi-drug resistance. Conclusions. Initial antimicrobial suppression to support fracture healing followed by definitive infection eradication surgery was associated with successful treatment in 93% of patients. The likelihood of remission of infection increases when eradication surgery is performed in a healed bone. This approach was not associated with an increased risk of developing multi-drug-resistant infections compared to contemporary bone infection cohorts in the published literature

Prosthetic joint infection (PJI) remains one of the most challenging complications to manage following total joint arthroplasty (TJA). There is a paucity of published data on the management of PJI in smaller, rural hospital settings. In this study, we investigate [1] the success rate of surgical management for PJI following TJA and [2] the microbiology of infecting organisms in this unique geographical environment. We performed a retrospective single-centre study at a rural hospital (Southland Hospital, Invercargill, New Zealand) over a 3-year period (2019 to 2022). All patients presenting with a first episode of PJI fulfilling Musculoskeletal Infection Society criteria after hip or knee arthroplasty were included. All patients had a minimum follow up of 6 months. Treatment success was defined eradication of infection. Twenty-one cases (14 hips and 7 knees) were identified. These were managed with Debridement, antibiotics, and implant retention (DAIR) procedure (n=14, 67%), single-stage revision (n=6, 29%), or long-term suppressive antibiotics (n=1, 4%). Of the DAIR patients, infection recurred in 50% and underwent subsequent revision. Of the single-stage revision patients, 17% failed and underwent subsequent revision. The overall success rate was 90%. Methicillin-sensitive Staphylococcus aureus (MSSA) was the most isolated pathogen (57%,) with no methicillin-resistance Staphylococcus aureus (MRSA) identified. Overall, 90% of infecting organisms were cefazolin sensitive. These results suggest that management of PJI is a safe and viable treatment option when performed in a rural hospital setting, with comparable treatment success rates to urban centres. The incidence of MRSA is low in this setting. Rates of antibiotic resistance were relatively low and most organisms were sensitive to cefazolin, the routine antibiotic used in prophylaxis