Mobility plays an important role, in particular for patients with osteoporosis and after trauma surgery, both as an outcome and as treatment. Mobility is closely linked to the patient”s quality of life and exercise is a powerful additional treatment option. In order to be able to generate an evidence base to evaluate various surgical and non-surgical treatment options, objective measurements of patient mobility and exercise over a certain time period are needed. Wearables are a promising candidate, with obvious advantages compared to questionnaires and/or PROs. However, when extracting parameters with wearables, one often faces the problem of algorithms not performing well enough for special cases like slow gait speeds or impaired gait, as they typically appear in this patient group. We plan to further extend the applicability of the actibelt system (3D accelerometer, 100Hz), in particular to improve the measurement precision of real-world walking speed in slow and impaired walking. We are using a special measurement wheel including a rotating 3D accelerometer that allows to capture high quality real-world walking speed and distance measurements, and a mobile high resolution camera system. In a first block 20 patients with osteoporosis were included in the study at the Ludwigs-Maximilians-University”s Department of General, Trauma and Reconstructive Surgery in Munich, Germany and equipped with an actibelt. Patients were asked to walk as “normal” as possible, while wearing their usual apparel, in the building and outside the building. They climbed stairs and had to deal with all unexpected “stop and go” events that appear in real-world walking. Various gait parameters will be extracted from the recorded data and compared to the gold standard. We will then tune the existing algorithms as well as new algorithms (e.g. step detection based on continuous wavelet transformation) to explore potential improvements of both step detection and speed estimation algorithms. Further refinement and validation using real world data is warranted

Variations in pelvic anatomy are a major risk factor for misplaced percutaneous sacroiliac screws used to treat unstable posterior pelvic ring injuries. A better understanding of pelvic morphology improves preoperative planning and therefore minimises the risk of malpositioned screws, neurological or vascular injuries, failed fixation or malreduction. Hence a classification system which identifies the clinically important anatomical variations of the sacrum would improve communication among pelvic surgeons and inform treatment strategy.

300 Pelvic CT scans from skeletally mature trauma patients that did not have pre-existing posterior pelvic pathology were identified. Axial and coronal transosseous corridor widths at both S1 and S2 were recorded. Additionally, the S1 lateral mass angle were also calculated. Pelvises were classified based upon the sacroiliac joint (SIJ) height using the midpoint of the anterior cortex of L5 as a reference point. Four distinct types could be identified:

Differences in transosseous corridor widths and lateral mass angles between classification types were assessed using two-way ANOVAs.

Type-B was the most common pelvic type followed by Type-A, Type-C, and Type-D. Significant differences in the axial and coronal corridors was observed for all pelvic types at each level. Lateral mass angles increased from Types-A to C, but were smaller in Type-D.

This classification system offers a guide to surgeons navigating variable pelvic anatomy and understanding how it is associated with the differences in transosseous sacral corridors. It can assist surgeons’ preoperative planning of screw position, choice of fixation or the need for technological assistance.

The aim of this study was to validate the use of three models of fracture fixation in the assessment of technical skills. We recruited 21 subjects (six experts, seven intermediates, and eight novices) to perform three procedures: application of a dynamic compression plate on a cadaver porcine model, insertion of an unreamed tibial intramedullary nail, and application of a forearm external fixator, both on synthetic bone models. The primary outcome measures were the Objective Structural Assessment of technical skills global rating scale on video recordings of the procedures which were scored by two independent expert observers, and the hand movements of the surgeons which were analysed using the Imperial College Surgical Assessment Device.

The video scores were significantly different for the three groups in all three procedures (p < 0.05), with excellent inter-rater reliability (α = 0.88). The novice and intermediate groups specifically were significantly different in their performance with dynamic compression plate and intramedullary nails (p < 0.05). Movement analysis distinguished between the three groups in the dynamic compression plate model, but a ceiling effect was demonstrated in the intramedullary nail and external fixator procedures, where intermediates and experts performed to comparable standards (p > 0.6). A total of 85% (18 of 21) of the subjects found the dynamic compression model and 57% (12 of 21) found all the models acceptable tools of assessment.

This study has validated a low-cost, high-fidelity porcine dynamic compression plate model using video rating scores for skills assessment and movement analysis. It has also demonstrated that Synbone models for the application of and intramedullary nail and an external fixator are less sensitive and should be improved for further assessment of surgical skills in trauma. The availability of valid objective tools of assessment of surgical skills allows further studies into improving methods of training.

Since the emergence of the COVID-19 pandemic, the NHS has been under unprecedentedpressure. Elective surgery had ceased, and trauma surgery has decreased dramatically. Surgical training is multi-faceted and requires a specialist trainee to have a timetable which includes regular elective non-emergency operating, trauma operating and training in outpatient clinics. Consequently, training in theatre and the achievement of operative numbers and index procedures had not been possible for Trauma and Orthopaedic (T&O) specialist trainees. The Joint Committee on Surgical Training (JCST) has clear training index requirements for all T&O specialist trainees. In this study, we surveyed specialist trainees in the North West London deanery against the annual requirements set by the JCST guidelines. In addition, we retrospectively assessed the total number of trauma referrals and operations scheduled in our unit during the COVID-19 outbreak compared to that one year previously. The aim of this study is to objectively assess the effect the pandemic has on T&O specialist training. A total of 24 responses were collected from specialist trainees. The results of the survey showed 87% of trainees believed that their training had been affected. 75% of trainees felt they were not on track to meet operative numbers for the year, and 71% felt index number achievement had been affected. Trauma case numbers dropped by 20% compared to that one year previously. We recommend timely, planned and conscientious remediation for specialist trainees’ educational requirements. Specialist trainees must take responsibility for their training and use of additional educational opportunities. Clinical supervisors and training programme directors must provide additional support and guidance to achieve ARCP outcomes however in some scenarios extension of training may be necessary

Abstract. Objectives. Our objective was to determine the incidence of post-operative COVID-19 infection within the first two weeks following treatment at the COVID-free site. During the COVID-19 pandemic our hospital saw one of the highest rates of COVID-19 infection in the United Kingdom. As a result, our trauma services were relocated to a vacant private elective hospital to provide a ‘COVID-free’ setting for trauma patients. Patients admitted to the COVID-free site were screened for coronavirus infection and only treated at that site if asymptomatic. Those with symptoms were treated at the ‘COVID’ site. Method. We collected data at the COVID-free site during the first seven weeks of its’ establishment. Inclusion criteria were all patients presenting for operative management of limb trauma; however, fragility hip fractures were excluded. All patients were screened for symptoms of COVID-19 infection at their 2-week follow-up appointment. Results. 72 patients presented to our service during the study period. The mean age was 34.9 years (21 to 89). 62 patients had general anaesthesia (86%), 7 patients had regional anaesthesia (10%) and 3 patients had local anaesthesia (4%). One asymptotic patient who was swabbed for COVID-19 on admission returned a positive result. This patient had contracted the infection before surgery and was excluded from further analysis. 71 patients (100%) remained asymptomatic at follow-up and none had required medical attention for suspected COVID-19 infection. Conclusion. A ‘COVID-free’ trauma service was established in a private elective hospital during the pandemic. None of the patients undergoing urgent trauma surgery in this setting developed COVID-19 symptoms as a result of their hospital admission. Establishing a separate site with screening to avoid admission of patients with COVID-19 infection can allow safe emergency surgery. This data can support informed consent and reassure patients of their risks when we resume day case and elective surgery. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Objectives. Infection of implants is a major problem in elective and trauma surgery. Heating is an effective way to reduce the bacterial load in food preparation, and studies on hyperthermia treatment for cancer have shown that it is possible to heat metal objects with pulsed electromagnetic fields selectively (PEMF), also known as induction heating. We therefore set out to answer the following research question: is non-contact induction heating of metallic implants effective in reducing bacterial load in vitro?. Methods. Titanium alloy cylinders (Ti6Al4V) were exposed to PEMF from an induction heater with maximum 2000 watts at 27 kHz after being contaminated with five different types of micro-organisms: Staphylococcus epidermidis; Staphylococcus aureus; Pseudomonas aeruginosa; spore-forming Bacillus cereus; and yeast Candida albicans. The cylinders were exposed to incremental target temperatures (35°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C) for up to 3.5 minutes. Results. There was an average linear heating rate of 0.39°C per second up to the target temperature, and thereafter the target temperature was maintained until the end of the experiment. At 60°C and higher (duration 3.5 minutes), there was a 6-log reduction or higher for every micro-organism tested. At 60°C, we found that the shortest duration of effective induction heating was 1.5 minutes. This resulted in a 5-log reduction or higher for every micro-organism tested. Conclusion. Non-contact induction heating of a titanium disk is effective in reducing bacterial load in vitro. These promising results can be further explored as a new treatment modality for infections of metal orthopaedic implants. Cite this article: B. G. Pijls, I. M. J. G. Sanders, E. J. Kuijper, R. G. H. H. Nelissen. Non-contact electromagnetic induction heating for eradicating bacteria and yeasts on biomaterials and possible relevance to orthopaedic implant infections: In vitro findings. Bone Joint Res 2017;6:323–330. DOI: 10.1302/2046-3758.65.BJR-2016-0308.R1

Device-associated infection remains a serious clinical problem in orthopaedic and trauma surgery. The emergence of resistant organisms such as methicillin resistant Staphylococcus aureus (MRSA) has further exacerbated this problem by limiting the range of treatment options. Currently, systemic antibiotic therapy is the cornerstone of treatment, alongside surgical resection of infected tissues and implant removal. The potential for antibiotic loaded biomaterials to support the prevention and treatment of infection is significant, although the currently available options are limited in number and often re-purposed from other applications e.g. antibiotic loading of bone cement. The first part of the talk will cover the basic concepts involved in antibiotic treatment, with an emphasis on the ideal antibiotic release kinetics from biomaterials, and how bacterial biofilms and antibiotic resistance influence antimicrobial efficacy. The next generation of biomaterials for antibiotic delivery should be specifically designed with this knowledge in mind. Regulatory approval of antimicrobial combination devices, however, is an evolving process as regulatory bodies seek more robust and clinically relevant efficacy data. Approval will require preclinical efficacy using standardized animal models that recapitulate the key features of the clinical disease. The second part of this talk will cover best practice in this important stage of development

Transverse patella fractures are commonly encountered in trauma surgery, open reduction and internal fixation are considered the gold standard treatment modality that could permit early knee motion and immediate rehabilitation. Many fixation methods had been defined and compared to each other's in many clinical and biomechanical studies. The aim of this study was to assess the safety and stability of our novel anatomical patella plate and to compare its stability with tension band-wire technique. A total of 12 cadaveric preserved knees (six right and six left patellae) with close patellar size were chosen to form two groups of six samples. Each group received either plate or tension band-wiring fixation for an experimentally created patella fracture. Cyclic load of an average of 350 N was applied for all specimens and after accomplishing 50 cycles the displacements of all fracture edges were recorded. After completing 50 cycles in each group, the average fracture edges displacement measured in the plate group was 1.98 ± 0.299 mm, whereas the average fracture edges displacement measured in the tension band-wire group was 2.85 ± 0.768 mm (p = 0.016). In the operative treatment of displaced transverse patellar fractures, the strength of fixation obtained by titanium curved plates is highly stronger when compared to the fixation with a tension band-wire technique. Fixation with titanium curved plates provides satisfactory stability at the fracture site which allow withstanding the cyclic loads during the postoperative rehabilitation

The implementation of knee arthrodesis has become synonymous with limb salvage in the presence of chronic sepsis and bone loss around the knee. This can be seen in failed trauma surgery or knee arthroplasty as an alternative to trans-femoral amputation. There is no prior literature assessing which factors affect knee arthrodesis using external fixation devices. Sixteen consecutive patients (four women and twelve men) made up of eleven infected knee implants, three internal fixations of the tibial following fractured tibial plateau as well as 2 infected native joints were identified. The mean age at initial surgery was 56 years (range 25 to 82 years). All procedures were performed under the direct supervision of the limb reconstruction teams using a standard protocol with either a Taylor spatial frame or Ilizarov frame. The patient records, microbiology results and radiographs of all patients who underwent knee arthrodesis at this institution between 1999 and 2010 were reviewed. Of the 16 patients in this study knee fusion occurred in eleven patients (69%). The five patients where arthrodesis failed all had significant bone loss on the pre-operative radiographs and confirmed at surgery. We found a relationship between a significant infection of the knee with MRSA and failure to fuse. Three of the five patients had MRSA isolated from inside the knee at some stage during their treatment. The five patients where fusion failed were on average older (mean age 63 years against 51 years) and had more extensive bone loss. Those who failed to fuse had more co-morbidities. We would conclude that where there is little or no bone loss, arthrodesis of the knee can be reliably achieved with the use of circular frame fixation. A greater number of negative factors also prolongs the amount of time spent in the external fixator. The presence of significant bone loss, infection, increased age and multiple co-morbidities requires careful evaluation and consideration of trans-femoral amputation as an alternative

Besides eliminating pain, restoring activity is a major goal in orthopaedic interventions including joint replacement or trauma surgery following falls in frail elderly, both treatments of highest socio-economic impact. In joint replacement and even more so in frail elderly at risk of falling, turns are assessed in clinical tests such as the TUG (Timed Get-up-and-Go), Tinetti, or SPPB so that classifying turning movements in the free field with wearable activity monitors promises clinically valuable objective diagnostic or outcome parameters. It is the aim of this study to validate a computationally simple turn detection algorithm for a leg-worn activity monitor comprising 3D gyroscopes. A previously developed and validated activity classification algorithm for thigh-worn accelerometers was extended by adding a turn detection algorithm to its decision tree structure and using the 3D gyroscope of a new 9-axis IMU (56×40×15mm, 25g, f=50Hz,). Based on published principles (El-Gohary et al. Sensors 2014), the turn detection algorithm filters the x-axis (thigh) for noise and walking (Butterworth low-pass, 2. nd. order with a cut-off at 4Hz and 4. th. order with a cut-off at 0.3Hz) before using a rotational speed threshold of 15deg/s to identify a turn and taking the bi-lateral zero-crossings as start and stop markers to integrate the turning angle. For validation, a test subject wore an activity monitor on both thighs and performed a total of 57 turns of various types (walking, on-the-spot, fast/slow), ranges (45 to 360deg) and directions (left/right) in free order while being video-taped. An independent observer annotated the video so that the algorithmic counts could be compared to n=114 turns. Video-observation was compared to the algorithmic classification in a confusion matrix and the detection accuracy (true positives) was calculated. In addition, 4-day continuous activity measures from 4 test subjects (2 healthy, 2 frail elderly) were compared. Overall, only 5/114 turns were undetected producing a 96% detection accuracy. No false positives were classified. However, when detection accuracy was calculated for turning angle intervals (45°: 30–67.5°; 90°: 67.5–135°; 180°: 135–270°; 360°: 270–450°), accuracy for all interval classifications combined dropped to 83.3% with equal values for left and right turns. For the 180° and 360°, accuracy was 100% while for the shorter 45° and 90° turns accuracy was 75% and 71% only, mainly because subsequent turns were not separated. Healthy subjects performed between 470 (office worker) and 823 (house wife) turns/day while frail elderly scored 128 (high fall risk) to 487 turns/day (low fall risk). Turns/day and steps/day were not correlated. In healthy subjects ca. 50% of turns were in the 45° category compared to only ca. 35% in frail elderly. Turn detection for a thigh-worn IMU activity monitor using a computationally simple algorithm is feasible with high general detection accuracy. The classification and separation of subsequent short turns can be further improved. In multi-day measurement, turns/day and the distribution of short and long turns seem to be a largely independent activity parameter compared to step counts and may improve objective assessment of fall risk or arthroplasty outcome

The stress response to trauma is the summation of the physiological response to the injury (the ‘first hit’) and by the response to any on-going physiological disturbance or subsequent trauma surgery (the ‘second hit’). Our animal model was developed in order to allow the study of each of these components of the stress response to major trauma. High-energy, comminuted fracture of the long bones and severe soft-tissue injuries in this model resulted in a significant tropotropic (depressor) cardiovascular response, transcardiac embolism of medullary contents and activation of the coagulation system. Subsequent stabilisation of the fractures using intramedullary nails did not significantly exacerbate any of these responses

Introduction. Iliac crest bone marrow aspirate (ICBMA) is frequently cited as the ‘gold-standard’ source of MSCs. MSCs have been shown to reside within the intramedullary (IM) cavities of long-bones [Nelea, 2005] however a comparative assessment with ICBMA has not yet been performed and the phenotype of the latter compartment MSCs remains undefined in their native environment. Methods. Aspiration of the IM cavities of 6 patients' femurs with matched ICBMA was performed. The long-bone-fatty-bone-marrow (LBFBM) was filtered (70μm) to separate liquid and solid fractions and the solid fraction was briefly (60min, 37oC) digested with collagenase. MSC enumeration was performed using the colony-forming-unit-fibroblast (CFU-F) assay and quantification of cells with the CD45low CD271+ phenotype by flow-cytometry. [Jones 2002, Buhring 2007] MSCs were cultured and standard expansion media and passage 2 cells were differentiated towards osteogenic, adipogenic and chondrogenic lineages. Results. ICBMA and LBFBM-liquid had similar median frequencies of MSCs/CFU-Fs per 200μl of sample (median 8, range 2-21, and 14, 0-53, respectively). LBFBM-solid fraction contained ∼10-fold more MSCs (116, 23-171). Correspondingly, LBFBM-solid fraction contained the highest proportions of CD45low CD271+ cells (median 0.315, 0.221-0.874) compared with (0.052, 0.023-0.083 and 0.152, 0.063-0.956) for ICBMA and LBFBM-liquid respectively (N =4) - thus sharing this phenotype of ICBMA cells. LBFBM MSCs were negative for the CD34 marker which has previously been reported on extra-bone marrow fat sources [Lin 2008]. MSCs isolated from the LBFBM phases were equivalent to ICBMA in terms of their osteogenic, chondrogenic or adipogenic potencies and their phenotypes following expansion was consistent with MSCs (CD73+ CD90+ CD105+CD33-CD34- CD45-). Conclusions. Intra-medullary cavities of long-bones are frequently accessed by the orthopaedic/trauma surgeon. Aspiration of LBFBM prior to reaming insertion of prosthesis/nail is a ‘low-tech’ method of harvesting large numbers of MSCs that can be liberated by brief enzymatic digestion. LBFBM can be used as an alternative to ICBMA for autologous use in trauma surgery. Both the in vivo phenotypes and functionality of LBFBM and ICBMA are comparable

Objectives

Thermal stability is a key property in determining the suitability of an antibiotic agent for local application in the treatment of orthopaedic infections. Despite the fact that long-term therapy is a stated goal of novel local delivery carriers, data describing thermal stability over a long period are scarce, and studies that avoid interference from specific carrier materials are absent from the orthopaedic literature.

Objectives

Venous thromboembolism (VTE) is a major potential complication following orthopaedic surgery. Subcutaneously administered enoxaparin has been used as the benchmark to reduce the incidence of VTE. However, concerns have been raised regarding the long-term administration of enoxaparin and its possible negative effects on bone healing and bone density with an increase of the risk of osteoporotic fractures. New oral anticoagulants such as rivaroxaban have recently been introduced, however, there is a lack of information regarding how these drugs affect bone metabolism and post-operative bone healing.

Objectives

The effects of disease progression and common tendinopathy treatments on the tissue characteristics of human rotator cuff tendons have not previously been evaluated in detail owing to a lack of suitable sampling techniques. This study evaluated the structural characteristics of torn human supraspinatus tendons across the full disease spectrum, and the short-term effects of subacromial corticosteroid injections (SCIs) and subacromial decompression (SAD) surgery on these structural characteristics.