Background

Virtual Reality (VR) uses headsets and motion-tracked controllers so surgeons can perform simulated total hip arthroplasty (THA) in a fully-immersive, interactive 3D operating theatre. The aim of this study was to investigate the effect of laboratory-based VR training on the ability of surgical trainees to perform direct anterior approach THA on cadavers.

Though the perceived advantages of computer assisted orthopaedic systems (CAOS) have been claimed incessantly over the years, these systems are far from commonplace in most orthopaedic theatres. Here, we present a summary of those very reasons.

Health Technology Assessment report elicited no proof of clinical benefits of the Robodoc over conventional procedures. Mazoochian et al were unable to confirm the same accuracy of implant position while using the Caspar. Honl et al found a higher revision and dislocation rate accompanied with longer surgery durations when robotic assisted technology was used.

Shortcomings identified in the CT-based navigation systems included an additional CT scan, which represents extra costs for the acquisition as well as additional radiation to the patient. Sistan et al claims that image-free navigational systems in knee arthroplasty do not provide a more reliable means for rotational alignment as compared to traditional techniques. Computer assisted pedicle screw insertion in the spine has also not demonstrated any significant clinical advantages.

To date, long term results of computer-guided or robot-assisted implantation of endoprosthetic devices are still lacking. With the unproven long-term clinical and functional results of patients who had computer aided surgery and given the multi-factorial complexities of patient outcome, it is difficult to claim via small scale short term studies that these systems present a significant benefit to the patient or the healthcare providers. Potential benefits of long-term outcome, better implant survival and functional improvement require further investigation and until that information is available this technology must be further developed before its widespread usage can be justified.

Aims

The aim of this study was to evaluate the suitability, against an accepted international standard, of a linked hip fracture registry and routinely collected administrative dataset in England to embed and deliver randomized controlled trials (RCTs).

Single level discectomy (SLD) is one of the most commonly performed spinal surgery procedures. Two key drivers of their cost-of-care are duration of surgery (DOS) and postoperative length of stay (LOS). Therefore, the ability to preoperatively predict SLD DOS and LOS has substantial implications for both hospital and healthcare system finances, scheduling and resource allocation. As such, the goal of this study was to predict DOS and LOS for SLD using machine learning models (MLMs) constructed on preoperative factors using a large North American database. The American College of Surgeons (ACS) National Surgical and Quality Improvement (NSQIP) database was queried for SLD procedures from 2014-2019. The dataset was split in a 60/20/20 ratio of training/validation/testing based on year. Various MLMs (traditional regression models, tree-based models, and multilayer perceptron neural networks) were used and evaluated according to 1) mean squared error (MSE), 2) buffer accuracy (the number of times the predicted target was within a predesignated buffer), and 3) classification accuracy (the number of times the correct class was predicted by the models). To ensure real world applicability, the results of the models were compared to a mean regressor model. A total of 11,525 patients were included in this study. During validation, the neural network model (NNM) had the best MSEs for DOS (0.99) and LOS (0.67). During testing, the NNM had the best MSEs for DOS (0.89) and LOS (0.65). The NNM yielded the best 30-minute buffer accuracy for DOS (70.9%) and ≤120 min, >120 min classification accuracy (86.8%). The NNM had the best 1-day buffer accuracy for LOS (84.5%) and ≤2 days, >2 days classification accuracy (94.6%). All models were more accurate than the mean regressors for both DOS and LOS predictions. We successfully demonstrated that MLMs can be used to accurately predict the DOS and LOS of SLD based on preoperative factors. This big-data application has significant practical implications with respect to surgical scheduling and inpatient bedflow, as well as major implications for both private and publicly funded healthcare systems. Incorporating this artificial intelligence technique in real-time hospital operations would be enhanced by including institution-specific operational factors such as surgical team and operating room workflow

Abstract. Objectives. Non-technical skills including teamwork play a pivotal role in surgical outcomes. Virtual reality is effective at improving technical skills, however there is a paucity of evidence on team-based virtual reality (VR) training. This study aimed to assess if multiplayer virtual reality training was superior to solo training for acquisition of both technical and non-technical skills in learning the complex anterior approach total hip arthroplasty operation. Methods. 10 novice surgeons and 10 novice scrub nurses, were randomised to solo or team virtual reality training to perform anterior approach total hip arthroplasty. Solo participants trained with virtual avatar counterparts, whilst teams trained in pairs (surgeon and scrub nurse). Both groups underwent 5 VR training sessions over 6 weeks. Then, they underwent a real-life assessment in which they performed AA-THA on a high-fidelity model with real equipment in a simulated operating theatre. Teams performed together and solo participants were randomly paired up with a solo player of the opposite role. Videos of the assessment were marked by two blinded expert assessors. Outcomes were procedure time, procedural errors from an expert pre-defined protocol and acetabular component positioning. Non-technical skills were assessed using the NOTECHs II and NOTSS scores. Results. Teams were 28.11% faster than solos in the real world assessment (31.22 minutes ±2.02 vs 43.43 ±2.71, p=0.01), with 34.91% less errors (−15.25 errors ±3.09 vs −23.43 ±1.84, p=0.04). Teams had significantly higher NOTSS and NOTECHS II scores when compared to solos (p<0.001). 8/10 surgeons placed the acetabular component within the target safe zone. Conclusions. Multiplayer training appears to lead to faster surgery with fewer technical errors and the development of superior non-technical skills. VR learnt skills appear to translate to the physical world. This supports the application of multidisciplinary learning to create a more integrated approach to surgical team training

Objective. To evaluate the clinical and functional outcomes obtained by combination of high-flexion Freedom® Total Knee System (TKS) and mini-subvastus approach in total knee replacement patients. Method. This is a retrospective, observational, real world study conducted at Mumbai in India from 2011 to 2016. All patients who were above the age of 18 and operated for total knee replacement (TKR) with mini-subvastus approach using Freedom (Maxx Medical) by the senior author were included. The Implant survivorship was the survey endpoint; primary endpoint was range of motion (ROM); and secondary endpoints were AKSS (American Knee Society Score) and WOMAC (Western Ontario and McMaster Universities Osteoarthritis) scores collected pre- and post-operatively. Results. 184 patients with 242 knees (126 unilateral and 58 bilateral) were operated with high-flexion TKS. Average age of patients was 70 ± 6.2 years. The mean ROM increased from 99.4°±10.44° (50°-120°) preoperatively to 116.78°±8.18° (88°–140°) postoperatively (p<0.001). Clinical and functional AKSS scores improved from 60.83±5.12 to 91.16±2.19 (p<0.001) and 65.35±3.52 to 99.13±4.61 (p<0.001) respectively. There average WOMAC pain scores improved from 12.12±1.72 to 0.066±0.37 (<0.0001). Moreover, post-operative WOMAC stiffness and function scores depicted significant improvement from 4.43±0.97 to 0.03±0.26 (p<0.0001) and 0.03±0.26 to 0.18±1.21 (p<0.0001) respectively at a mean follow-up of 3.71 ± 0.98 years. Implant survivorship was 100%. Conclusion. High-flexion Freedom® TKS demonstrated a satisfactory clinical and functional improvements including high flexion when operated by the mini-subvastus approach at a mean FU of 4 years

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

Pedicle screws give the best bone purchase of all posterior fixation techniques of the cervical spine, which would suggest a frequent utilisation. However, the cervical pedicles are small and the potential danger of misplacing a screw limits their use. In in vitrostudies the misplacement frequency has been shown to be unacceptably high, whereas this is not seen clinically, maybe due to different insertion techniques. Fortunately a misplaced screw rarely leads to a clinical complication. To minimise the risks, however, we now only use pedicle screws in the cervical spine where stability is critical, i.e. at the extremes of a fixation. For example: A C1–C2 fixation in rheumatoid arthritis or in fracture of the dens would utilise C2–C1 transarticular screws (i.e. C2 pedicle screws). A cranio-cervical or cranio-thoracic fixation would involve 1 or 2 levels of pedicle screws as distal anchorage, and lateral mass screws in between. A short cervical fixation with pedicle screws could be in a trauma patient where it would be desired to have a very reliable fixation with a minimum number of fixation levels. Computer navigation is a promising technique, however, not free from misplaced screws. So far we have experience of 83 navigated screws in 18 patients evaluated with postoperative computed tomography (CT). 67 screws were in correct position, 11 had insignificant breach fractures of the pedicle wall, whereas 4 were incorrectly placed, usually laterally into the foramen for the vertebral artery, none however with a clinical consequence. The main problem with computer navigation in the c-spine seems to be to obtain a good enough CT scan to allow good matching between the virtual and real worlds

Cannulated screw fixation is currently the treatment of choice for slipped capital femoral epiphyses (SCFE). A SCFE module of the Bonedoc simulator was created in order to test the ability of advanced trainees to place the screw in the correct position, and the practicality of using the simulator within the orthopaedic surgery training curriculum. Bonedoc (University of Auckland) is a virtual reality simulator of image guided orthopaedic operations. 1. This simulator runs in Internet Explorer (Microsoft, USA) using the Octaga (Octaga, Norway) plugin. The total download is around 4 MB. The SCFE module was created from a CT scan of a Grade 2 acute on chronic SCFE. DICOM images were imported into 3DView (. www.rmrsystems.co.uk. ) and a mesh created. The generic femur from the DHS module was morphed within the CAD package Blender (Blender.org) to conform to this reconstructed SCFE mesh. Forty two advanced trainees operated on the same virtual SCFE during a training weekend. The trainees had 25 minutes to become familiar with the simulator and complete the operative case. The trainees performed all tasks relevant to the operation. At the operation’s conclusion the trainees self-assessed their performance. Subsequently the simulator provided surgically relevant objective feedback on aspects such as exact position of the screw, misplaced attempts and the number of x-rays. The results were analysed using SAS (SAS Institute, USA) in subgroups based on year on the scheme, as well as correlated within each operation. There was no difference in the accuracy with which the virtual slipped capital femoral epiphysis was pinned by trainees in different years in the training programme. However, 26 of the 39 of the virtual screws were placed in the superior direction. There was no correlation between number of X-ray images taken and final accuracy of screw placement. The number of misplaced drill holes was correlated both with number of X-ray images taken (p< 0.01) and operative time (p< 0.01) but not with final accuracy of the screw. An increase in misplaced attempts was correlated with angulation errors in the anterior plane (p< 0.01). There was no correlation between the trainees’ self assessment and any of the measured variables. The Bonedoc simulator provides a means to test trainees on technical aspects of a surgical procedure. It provides objective results, which can mimic real world outcomes. In addition, the ability to test all trainees on the same virtual operative case allows standardisation of assessment. All trainees completed the task to a similar level of accuracy, which may reflect the overall skill level in advanced trainees within the New Zealand. However, many trainees placed the screw in the superior portion of the femoral head, which is thought to increase the risk of avascular necrosis. 2. Further work is required to evaluate how accurately performance on the simulator predicts performance in the operating theatre

Navigation is the combination of real and virtual anatomy. Registration brings the virtual world of imaged anatomy into accordance with the real world of actual anatomy. Without a navigation system the process takes place in the head of the surgeon, he assigns the image data to the patient’s anatomy, based on his experience. This process is called mental registration. Registration methods: Every point in the patient’s anatomy correlates to one point in the three-dimensional image of the patient. Every point in the anatomy and the image can be clearly defined as a position vector in a Cartesian coordinate system. Registration is carried out by a series of transformations of the different Cartesian coordinate systems. The registration between the real and the virtual world can be performed manually or automatically. Different technologies are available for this process. In the Paired Points Matching landmarks, which can be clearly identified in the image dataset and in the in situ anatomy, are registered pre-operatively in a three-dimensional (e.g. CT) dataset. At least three points, registered as precisely as possible in the dataset and the intra-operative anatomy, are necessary to define the spatial position of the dataset and to bring it into correlation with the patients anatomy. On the spine, the existing prominent landmarks on the accessible dorsal part of the vertebrae, the dorsal process, and the joint condyles are used. Different factors contribute to an inaccurate registration, like an inadequate preparation of the anatomic structure, a misinterpretation of the landmarks by the surgeon, or anatomic variations, that formed in the time between the CT images and the operation. The definition of corresponding point pairs can be difficult in many applications and an increased degree of invasivity must be accepted. Therefore, the precise recognition of the predefined points of the image dataset in the patient’s anatomy is severely impaired. However, other characteristics, e.g. curves or surfaces of bones can be extracted from the image data. These form the basis for the Surface Matching. A series of points on the surface of the bone must then be digitalised intra-operatively. This accumulation of points is then transferred to the corresponding virtual surface with the help of a complex mathematic algorithm, so that the gap between the points and the surfaces is minimized. Under special circumstances the registration can be carried out automatically. For this it is necessary that the position of both coordinate systems is known at the time of image recording. To do this, a reference array needs to be attached to the patient and thus the automatic registration can only be performed intra-operatively. In general, all available intra-operative imaging equipment can be used. Bulky equipment, such as computer tomography or magnetic resonance imaging is available intra-operatively only in very few facilities. The most valuable source for intra-operative images is the image intensifier. Images can be recorded with a navigated, calibrated C-Arm in the standard positions relevant for the surgery. Several fluoroscopic image layers can be displayed at the same time as optical information in the operating room in the form of a permanent virtual fluoroscopy. Since 2001 a fluoroscopic image intensifier is available, which can generate three-dimensional multilayer reconstructions of high-contrast objects, like bones, from single fluoroscopic images. Since the introduction of three-dimensional imaging techniques in navigation, it is possible to perform the automatic registration of three-dimensional data. So, the above described limitations of CT-based navigation for minimal invasive surgery, e.g. not being able to update the dataset and errors during manual registration, were taken into account. However, the process of automatic registration is highly complex and influenced by many factors

Introduction: Legislation driven & technology aided reductions in mortality have been documented over the past 10 years for road traffic accidents (RTAs). However many authors have noted an increasing morbidity as a result of serious lower limb injuries. In collaboration with the Transport Research Laboratory (TRL) a 2 stage research programme has been carried out on fresh frozen PHMS lower limbs. This programme, has culminated in a specific series of PMHS tests to reproduce the most disabling lower limb injuries seen in real world accident data. The authors aimed to establish force thresholds for failure (fracture) of the calcaneus, talus and tibial plafond in frontal and frontal offset RTAs. This data is considered essential to support new pan-European legislation for better lower limb protection structures in new motor vehicles which is currently under discussion. Methods: A 5m bungee driven sled test facility capable of creating a validated and repeatable dynamic crash pulse was used to subject 15 PMHS lower limb specimens to, axial impact loading. The pulse was modelled on the accelerometer toe-pan recordings from a full-scale automotive crash test in frontal impact. To represent brake pedal intrusion at an impact velocity of up to 14ms. −1. , a staggered double impact, delaying application of axial loading was used. Impact loading was achieved via a modelled brake pedal to the mid-foot. All specimens were preloaded through the Achilles tendon and by knee extension to simulate the plantar flexing response seen in the foot & ankle in driving simulator studies. Delaying the application of axial loading after the initial impact and sled deceleration effectively imparts momentum into the specimen, further preloading the foot and ankle and thus increasing pre-impact bracing. Transducer data were recorded using high frequency (20 & 100 KHz) capture systems (K-Trader and Prosig). High-speed cinematography enabled additional kinematic analysis. Each specimen was tested once only. Specimens were selected at random for five impact severity groups. All specimens underwent pre impact BMD evaluation using protocols previously designed for this type of work. Post impact analysis included X-rays and necropsy. Results: The specimens used varied in BMD and age similar to specimens used in other centres for similar testing. In the 15 final test specimens 8 calcaneal fractures were generated, one with an additional talar neck fracture. Seven specimens did not sustain injury. Measured BMD did not appear to be a useful predictor of load to failure. Peak axial forces ranged from 5KN up to 14kN. Toe pan and foot accelerations up to 200g were generated. Discussion: This test method appears to predispose the calcaneus to injury. It failed to create either a Pilon fracture or an isolated talus fracture. Previous research investigating axial impact loading have applied a direct impact with varing levels of pre-load. They resulted in a range of injuries and suggested pre-loading reduced injury thresholds for talar and tibial injuries. This has not been our experience. Conclusions: This data is invaluable, enabling thresholds for legislative car crash testing to be authoritatively stated and incorporated into national and international standards

Computer assisted surgery is becoming more frequently used in the medical world. Navigation of surgical instruments and implants plays an important role in this surgery. OrthoPilot™ Hip Suite (BBraun Aesculap) is one such system used for hip navigation in orthopaedic surgery. However the accuracy of this system remains to be determined independently of the manufacturer. The manufacturer supplies a technical specification for the accuracy of the system (± 2 mm and ± 2°) and previous research has been undertaken to compare its clinical accuracy against conventional hip replacements by x-ray. This clinical validation is important but contains many sources of error or deviation from an ideal outcome in terms of the surgeons' use of the system, inaccurate palpation of landmarks, variation in actual cup position from that given by the navigation system and measurement of the final cup position. It is therefore not possible to validate the claims of the manufacturer from this data. There is no literature evaluating the technical accuracy of the software i.e. the accuracy of the system given known inputs. This study had two main aims 1) validating the accuracy of the OrthoPilot data while navigating the surgical instruments and 2) validating the accuracy of navigation algorithm inside the OrthoPilot system which determines cup implant placement. The OrthoPilot validation was performed and compared against the gold standard of a VICON movement analysis system. The system used was OrthoPilot™ with a Spectra camera from Northern Digital Inc. (Ontario, Canada). Software investigated was the Hip Suite THA cup only navigation software Version 3.1. The validation was performed and compared against the VICON Nexus version 1.4.116 with Bodybuilder software version 3.55. An aluminium pelvis phantom was used for measurement allowing accurate and repeatable inputs. The OrthoPilot system has three types of instruments sets; passive, active and hybrid. This study was carried out with the passive instruments set. Data were captured simultaneously from both the OrthoPilot and VICON systems for the supine position of the phantom. Distances between the anatomical land marks on the phantom were compared to test the data capturing accuracy of the OrthoPilot system. Anatomical land marks of right anterior superior iliac supine (RASIS), left anterior superior iliac supine (LASIS) and Pubic Symphasis (PS) were palpated to define the Anterior Pelvic Plane (APP). Distances between the anatomical landmarks of RASIS to LASIS, RASIS to PS and LASIS to PS were considered for comparison. Width and height of the pelvis was varied to examine different APPs. The width and height used were 170 mm and 53 mm, 230 mm and 88 mm, and 290 mm and 123 mm respectively. One hundred APP data sets were captured at each instance. The accuracy of the hip navigation algorithm was tested by applying similar algorithm to calculate the native anteversion and inclination angles of the acetabulum using the VICON system. Data were captured simultaneously from both OrthoPilot and VICON systems. Radiographic anteversion and inclination angles were obtained with phantom model, which had 14° of anteversion angle and 45° of inclination angle. APP of 230 mm in width and 88 mm in height was used to obtain anterior pelvic plane data. Position vectors for each anatomical land mark from the OrthoPilot system were extracted from relevant transformation matrices, while position vectors from the VICON system were extracted from static trial modelling. The distance data from both systems were compared with calibrated distance data from the phantom model. Mean values of the distances between anatomical landmarks were found to be similar for both OrthoPilot and VICON systems. In addition, these distances were comparable with the pelvic phantom model data, within 1 mm for all measured distances for the VICON and 2 mm for the OrthoPilot. Furthermore, the standard deviations were less than 1% of the measured value. Comparison was also made for the anteversion and inclination angles of the acetabulum of the pelvic model with OrthoPilot and VICON data. Both systems produced similar results for the mean angle values, within 0.5° of the known angles for the VICON and 1° for the OrthoPilot and with standard deviations of the measured values of less than 1%. All the data were captured simultaneously from both OrthoPilot and VICON systems under the same laboratory conditions. According to the above results it is clear that the distance readings obtained from the OrthoPilot are comparable to the results obtained from the gold standard VICON system and the calibrated distance readings of the phantom. In addition, acetabular angle results obtained from OrthoPilot are almost equivalent to results obtained from VICON and the calibrated phantom angles. Finally it is can be concluded that, both the data palpation with OrthoPilot system and acetabular angle calculation algorithm of the OrthoPilot system are accurate enough for the real world clinical tasks they are expected to perform

Aims

The aim of this study was to develop and evaluate machine-learning-based computerized adaptive tests (CATs) for the Oxford Hip Score (OHS), Oxford Knee Score (OKS), Oxford Shoulder Score (OSS), and the Oxford Elbow Score (OES) and its subscales.

Computers arrived late in orthopaedic surgery. While the rest of the world already happily integrated computers into daily life, business and production, orthopaedic surgeons remained sceptical and denied any need for help from modern technology. It was in the mid-eighties though, that a young veterinary surgeon from California, specializing in total hip replacement in dogs, was contemplating the problems that he encountered during surgery. This veterinary surgeon, the late Hap Paul, was one of the founding members of the custom – implant society, from which evolved ISTA. He struggled with wrong positioning of implants and broken bones, and wondered why implants that were manufactured with highest technology finally were placed into the bone with crude instruments reminiscent of those found in a carpenters workshop. With the help of IBM and engineers from the University of California he created a system which he called ROBODOC. ®. , and it became the first computer based system helping the surgeon during an orthopaedic procedure. The technological effort was huge, as many parts of the system and of the procedure using advance robotic tools had to be invented from scratch. There was nothing there they could copy, and the system they invented – an active robot performing a critical part of surgery – represented a very ambitious step forward. Some compare the development of ROBODOC. ®. with the technological history of the Concorde: very sophisticated technology, very early and very advanced, somewhat expensive and with an aura of vision and adventure. Of course this was not the only and ultimate solution of bringing computers into surgery. Other researchers took a step backwards: they invented systems that helped the surgeon to navigate hand held instruments and implants within the surgical field, so-called navigation systems. These were initially used by neurosurgeons to navigate probes within the brain. As neurosurgeons were closely related to and depending on CT-scan, the logic step was to use the CT- datasets, match them with real world (the process of registration) and create a virtual 3D space that is congruent to the real 3D space. Using CT provided orthopaedic surgeons increase visibility with less required exposure. With the help of optical systems (other options are mechanical or magnetic systems) instruments can be tracked outside and inside the surgical object and allow precise navigation within the surgical field. However, preparation of tissue and/or placement of implants were still done with manual tools. Very early application of this navigation technology was spine surgery in the mid-nineties, where utmost precision was needed during the placement of pedicle screws. Further applications were knee replacement, hip replacement and numerous applications in trauma surgery. Also the source of data was further developed: from the very precise but costly CT-scan to simple radiographs taken during surgery to so-called image free surgery, where data are retrieved directly from the surgical object and approximations are created to direct the placement of implants. Navigation systems, in contrast to the original robotic system, presented two major advantages: they were much cheaper, and they allowed the surgeon to use his standard instruments and, most important, to play a more active part in the surgery, “to stay in the loop” (Tony DiGioia). Today there are thousands of navigations systems in routine use all over the world. Published results show benefits, but also limits. Surgery using navagation has become more precise and results more reproducible, yet there are still outliers which mainly stem from technical problems, but which are hard to detect and cause significant inaccuracy. Therefore the era of the robots is not over: robotic technology is currently revisited by numerous groups, and technically more advanced robots are developed and currently under testing. Robotic technology has continued to make inroads into the market with demonstrated capacity to assist the surgeon to reduce intraoperative complications, eliminate outliers, and achieve improved surgical outcomes consistently. Different types of robots (active, semi active and passive robots, such as systems which provide for constrained motion in the surgical field) are successfully moving into the operating theatre. ROBODOC. ®. , the forefather of all computer-assisted orthopaedic systems, is still around and actively applied during surgery, with published good results and high reliability. The history of ROBODOC. ®. is a master piece of technological history. After initial successful human surgeries, embedded in the feasibility study required by the FDA, the next step was more difficult: the randomized study for FDA approval to prove the efficacy almost killed the company and with it the technology. In early optimistic statements the inventors foresaw major benefits, but overlooked the difficulties to prove these in the postoperative outcome. Disadvantages of the system, like longer OR times and higher blood loss, at least prevalent in the in the early trials of the FDA study, were obvious while the “clear” benefits in outcome were not so obvious. Thus marketing abroad became a major option, and Europe became the prime target. The attempt was successful, and rapidly 30 systems were busy all over Europe. This development was brought to a halt by a couple of unsubstantiated lawsuits in Germany and unprecedented negative press campaign accompanying this effort. The lawsuits were sponsored by the illusion to finally sue an American company and gain millions from that lawsuit. This process started in the early days of this century, and so far, in spite of numerous sentences proclaimed, not one court has condemned the technology or found any wrong doing in applying it. In parallel with the declining European market, the Asian market was developed, and surgeons there benefited from the experiences in Europe and the consecutive improvements of the system. Currently TKR and THR are routinely performed using the ROBODOC. ®. system in Japan, Korea and India. This process let to recovery of the company, which tells us that technological progress also in medicine is inherently coupled to economic success. Although the first system applied in CAOS, Robodoc still is the most advanced system in technological terms. This is finally also accepted by the very critical USFDA, which had problems with the approval for such a long time because the system represents an autonomous robotic system working on patients. Initial problems like bulkiness, software bugs and invasiveness have been overcome. Work is underway even now to make the system more flexible covering a wider range of surgical procedures like uni and multi compartmental knee, hip resurfacing and acetabular cup in THR and further expanding the functionality of the system supporting not just orthopedic procedures but Neurosurgical procedures as well. Many of these developments are in the final stages of testing. In the meantime the CAOS community, i.e. the surgeons and engineers primarily working in application and development of the existing systems, more and more become convinced that computer assisted surgery undoubtedly is heading towards the integration of robotic systems into surgery: this is where ROBODOC. ®. came from

Aims

There is little published on the outcomes after restarting elective orthopaedic procedures following cessation of surgery due to the COVID-19 pandemic. During the pandemic, the reported perioperative mortality in patients who acquired SARS-CoV-2 infection while undergoing elective orthopaedic surgery was 18% to 20%. The aim of this study is to report the surgical outcomes, complications, and risk of developing COVID-19 in 2,316 consecutive patients who underwent elective orthopaedic surgery in the latter part of 2020 and comparing it to the same, pre-pandemic, period in 2019.

Aims

This systematic review places a recently completed multicentre randomized controlled trial (RCT), UK FROST, in the context of existing randomized evidence for the management of primary frozen shoulder. UK FROST compared the effectiveness of pre-specified physiotherapy techniques with a steroid injection (PTSI), manipulation under anaesthesia (MUA) with a steroid injection, and arthroscopic capsular release (ACR). This review updates a 2012 review focusing on the effectiveness of MUA, ACR, hydrodilatation, and PTSI.

Aims

To determine the role of early MRI in the management of suspected scaphoid fractures.

Objectives

Wear debris released from bearing surfaces has been shown to provoke negative immune responses in the recipient. Excessive wear has been linked to early failure of prostheses. Analysis using coordinate measuring machines (CMMs) can provide estimates of total volumetric material loss of explanted prostheses and can help to understand device failure. The accuracy of volumetric testing has been debated, with some investigators stating that only protocols involving hundreds of thousands of measurement points are sufficient. We looked to examine this assumption and to apply the findings to the clinical arena.