Aims. Traditionally, acetabular component insertion during total hip arthroplasty (THA) is visually assisted in the posterior approach and fluoroscopically assisted in the anterior approach. The present study examined the accuracy of a new surgeon during anterior (NSA) and posterior (NSP) THA using robotic arm-assisted technology compared to two experienced surgeons using traditional methods. Methods. Prospectively collected data was reviewed for 120 patients at two institutions. Data were collected on the first 30 anterior approach and the first 30 posterior approach surgeries performed by a newly graduated arthroplasty surgeon (all using robotic arm-assisted technology) and was compared to standard THA by an experienced anterior (SSA) and posterior surgeon (SSP). Acetabular component inclination, version, and leg length were calculated postoperatively and differences calculated based on postoperative film measurement. Results. Demographic data were similar between groups with the exception of BMI being lower in the NSA group (27.98 vs 25.2; p = 0.005). Operating time and total time in operating room (TTOR) was lower in the SSA (p < 0.001) and TTOR was higher in the NSP group (p = 0.014). Planned versus postoperative leg length discrepancy were similar among both anterior and posterior surgeries (p > 0.104). Planned versus postoperative abduction and anteversion were similar among the NSA and SSA (p > 0.425), whereas planned versus postoperative abduction and anteversion were lower in the NSP (p < 0.001). Outliers > 10 mm from planned leg length were present in one case of the SSP and NSP, with none in the anterior groups. There were no outliers > 10° in anterior or posterior for abduction in all surgeons. The SSP had six outliers > 10° in anteversion while the NSP had none (p = 0.004); the SSA had no outliers for anteversion while the NSA had one (p = 0.500). Conclusion. Robotic arm-assisted technology allowed a newly trained surgeon to produce similarly accurate results and outcomes as experienced surgeons in anterior and posterior hip arthroplasty. Cite this article: Bone Jt Open 2021;2(6):365–370

We aim to explore the potential technologies for monitoring and assessment of patients undergoing arthroplasty by examining selected literature focusing on the technology currently available and reflecting on possible future development and application. The reviewed literature indicates a large variety of different hardware and software, widely available and used in a limited manner, to assess patients’ performance. There are extensive opportunities to enhance and integrate the systems which are already in existence to develop patient-specific pathways for rehabilitation. Cite this article: Bone Joint J 2022;104-B(10):1104–1109

The computational modelling and 3D technology are finding more and more applications in the medical field. Orthopedic surgery is one of the specialties that can benefit the most from this solution. Three case reports drawn from the experience of the authors’ Orthopedic Clinic are illustraded to highlight the benefits of applying this technology. Drawing on the extensive experience gained within the authors’ Operating Unit, three cases regarding different body segments have been selected to prove the importance of 3D technology in preoperative planning and during the surgery. A sternal transplant by allograft from a cryopreserved cadaver, the realization of a custom made implant of the glenoid component in a two-stage revision of a reverse shoulder arthroplasty, and a case of revision on a hip prosthesis with acetabular bone loss (Paprosky 3B) treated with custom system. In all cases the surgery was planned using 3D processing software and models of the affected bone segments, printed by 3D printer, and based on CT scans of the patients. The surgical implant was managed with dedicated instruments. The use of 3D technology can improve the results of orthopedic surgery in many ways: by optimizing the outcomes of the operation as it allows a preliminary study of the bone loss and an evalutation of feasibility of the surgery, it improves the precision of the positioning of the implant, especially in the context of severe deformity and bone loss, and it reduces the operating time; by improving surgeon training; by increasing patient involvement in decision making and informed consent. 3D technology, by offering targeted and customized solutions, is a valid tool to obtain the tailored care that every patient needs and deserves, also providing the surgeon with an important help in cases of great complexity

An overview about 3D printing technology in orthopaedic applications will be given based on examples. The process from early prototypes to certified implants coming from serial production will be demonstrated also considering relevant surrounding conditions. Today's focus is mostly on orthopaedic implants, but there is a high potential for new implant-related surgical instrument solutions taking into account up-coming clinical demands and user needs accessible by actual 3D printing technologies

Digital Ventilated Cages (DVC) offer an innovative technology to obtain accurate movement data from a single mouse over time [1]. Thus, they could be used to determine the occurrence of a tendon damage event as well as inform on tissue regeneration [2,3]. Therefore, using the mouse model of tendon experimental damage, in this study it has been tested whether the recovery of tissue microarchitecture and of extracellular matrix (ECM) correlates with the motion data collected through this technology. Mice models were used to induce acute injury in Achilles tendons (ATs), while healthy ones were used as control. During the healing process, the mice were housed in DVC cages (Tecniplast) to monitor animal welfare and to study biomechanics assessing movement activity, an indicator of the recovery of tendon tissue functionality. After 28 days, the AT were harvested and assessed for their histological and immunohistochemical properties to obtain a total histological score (TSH) that was then correlated to the movement data. DVC cages showed the capacity to distinguish activity patterns in groups from the two different conditions. The data collected showed that the mice with access to the mouse wheel had a higher activity as compared to the blocked wheel group, which suggests that the extra movement during tendon healing improved motion ability. The histological results showed a clear difference between different analyzed groups. The bilateral free wheel group showed the best histological recovery, offering the highest TSH score, thus confirming the results of the DVC cages and the correlation between movement activity and structural recovery. Data obtained showed a correlation between TSH and the DVC cages, displaying structural and movement differences between the tested groups. This successful correlation allows the usage of DVC type cages as a non-invasive method to predict tissue regeneration and recovery. Acknowledgements: This research is part of the P4FIT project ESR13, funded by the H2020-ITN-EJD MSCA grant agreement No.955685

Aims. Total knee arthroplasty (TKA) using functional alignment aims to implant the components with minimal compromise of the soft-tissue envelope by restoring the plane and obliquity of the non-arthritic joint. The objective of this study was to determine the effect of TKA with functional alignment on mediolateral soft-tissue balance as assessed using intraoperative sensor-guided technology. Methods. This prospective study included 30 consecutive patients undergoing robotic-assisted TKA using the Stryker PS Triathlon implant with functional alignment. Intraoperative soft-tissue balance was assessed using sensor-guided technology after definitive component implantation; soft-tissue balance was defined as intercompartmental pressure difference (ICPD) of < 15 psi. Medial and lateral compartment pressures were recorded at 10°, 45°, and 90° of knee flexion. This study included 18 females (60%) and 12 males (40%) with a mean age of 65.2 years (SD 9.3). Mean preoperative hip-knee-ankle deformity was 6.3° varus (SD 2.7°). Results. TKA with functional alignment achieved balanced medial and lateral compartment pressures at 10° (25.0 psi (SD 6.1) vs 23.1 psi (SD 6.7), respectively; p = 0.140), 45° (21.4 psi (SD 5.9) vs 20.6 psi (SD 5.9), respectively; p = 0.510), and 90° (21.2 psi (SD 7.1) vs 21.6 psi (SD 9.0), respectively; p = 0.800) of knee flexion. Mean ICPD was 6.1 psi (SD 4.5; 0 to 14) at 10°, 5.4 psi (SD 3.9; 0 to 12) at 45°, and 4.9 psi (SD 4.45; 0 to 15) at 90° of knee flexion. Mean postoperative limb alignment was 2.2° varus (SD 1.0°). Conclusion. TKA using the functional alignment achieves balanced mediolateral soft-tissue tension through the arc of knee flexion as assessed using intraoperative pressure-sensor technology. Further clinical trials are required to determine if TKA with functional alignment translates to improvements in patient satisfaction and outcomes compared to conventional alignment techniques. Cite this article: Bone Joint J 2021;103-B(3):507–514

Introduction. The use of technology, such as navigation and robotic systems, may improve the accuracy of component positioning in total hip arthroplasty (THA) but its impact on patient reported outcomes measures (PROMs) remains unclear. This study aims to identify the association between intraoperative use of technology and patient reported outcomes measures (PROMs) in patients who underwent primary total hip arthroplasty (THA). Methods. We retrospectively reviewed patients who underwent primary THA between 2016 and 2020 and answered a post-operative PROM questionnaire. Patients were separated into three groups depending on the technology utilized intraoperatively: navigation, robotics, or no technology (i.e. manual THA. The Forgotten Joint Score (FJS-12) and Hip Disability and Osteoarthritis Outcome Score, Joint Replacement (HOOS, JR) were collected at various time points (FJS: 3m, 1y, and 2y; HOOS, JR: pre-operatively, 3m, and 1y). Demographic differences were assessed with chi-square and ANOVA. Mean scores between all groups were compared using univariate ANCOVA, controlling for observed demographic differences. Results. Of the 1,960 cases included, 896 navigation, 135 robotics, and 929 manual. There was a significant statistical difference in one-year HOOS, JR scores (85.23 vs. 85.95 vs. 86.76; p=0.014) and two-year FJS-12 scores (64.72 vs. 73.35 vs. 74.63; p=0.004) between the three groups. However, they did not exceed the mean clinically important difference (MCID) at any time period. Short and long-term PROMs significantly differed between navigation and manually performed cases (FJS 3m: p=0.047; FJS 2y: p=0.001; HOOS, JR 1y: p=0.004). Two-year FJS-12 scores statistically differed between navigation and robotics (p=0.038). There was no statistical difference in either FJS-12 or HOOS, JR scores between robotics and manual THA groups at all time points (FJS 3m:p=0.076, 1y:p=0.225, 2y:p=0.793; HOOS, JR preop:p=0.872, 3m:p=0.644, 1y:p=0.531). Conclusion. Statistical differences observed between all modalities are not likely to be clinically meaningful with regards to early patient reported outcomes. While intraoperative use of technology may improve the accuracy of implant placement, these modalities have not necessarily translated into improved early reported functional outcomes

Introduction. There is debate regarding whether the use of computer-assisted technology, such as navigation and robotics, has any benefit on clinical or patient reported outcomes following total knee arthroplasty (TKA). This study aims to report on the association between intraoperative use of technology and outcomes in patients who underwent primary TKA. Methods. We retrospectively reviewed 7,096 patients who underwent primary TKA from 2016–2020. Patients were stratified depending on the technology utilized intraoperatively: navigation, robotics, or no technology. Patient demographics, clinical data, Forgotten Joint Score-12 (FJS), and Knee injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS, JR) were collected at various time points up to 1-year follow-up. Demographic differences were assessed with chi-square and ANOVA tests. Clinical data and mean FJS and KOOS, JR scores were compared using univariate ANCOVA, controlling for demographic differences. Results. During the study period, 287 (4%) navigation, 367 (5%) robotics, and 6,442 (91%) manual cases were performed. Surgical time significantly differed between the three groups (113.33 vs. 117.44 vs. 102.11 respectively; p<0.001). Discharge disposition significantly differed between the three groups (p<0.001), with a greater percentage of patients who underwent manual TKA discharged to a skilled nursing facility (12% vs. 8% vs. 15%; p<0.001) than those who had intraoperative technology utilized. FJS scores did not statistically differ at 3-months (p=0.067) and 1-year (p=0.221) postoperatively. There was a significant statistical difference in three-month KOOS, JR scores (59.48 vs. 60.10 vs. 63.64; p=0.001); however, one-year scores did not statistically differ between the three groups (p=0.320). Mean improvement in KOOS, JR scores preoperatively to one-year postoperatively was significantly largest for the navigation group and least for robotics (27.12 vs. 23.78 vs. 25.42; p<0.001). Conclusion. This study demonstrates shorter mean operative time in cases with no utilization of technology and clinically similar patient reported outcome scores associated with TKAs performed between all modalities. While the use of intraoperative technology may aid surgeons, it has not currently translated to better short-term patient outcomes

The COVID-19 pandemic necessitated a pivot to online learning for many traditional, hands-on subjects such as anatomy. This, coupled with the increase in online education programmes, and the reduction of time students spend in anatomy dissection rooms, has highlighted a real need for innovative and accessible learning tools. This study describes the development of a novel 3-dimensional (3D), interactive anatomy teaching tool using structured light scanning (SLS) technology. This technique allows the 3D shape and texture of an object to be captured and displayed online, where it can be viewed and manipulated in real-time. Human bones of the upper limb, vertebrae and whole skulls were digitised using SLS using Einscan Pro2X/H scanners. The resulting meshes were then post-processed to add the captured textures and to remove any extraneous information. The final models were uploaded into Sketchfab where they were orientated, lit and annotated. To gather opinion on these models as effective teaching tools, surveys were completed by anatomy students (n=35) and anatomy educators (n=8). Data was collected using a Likert scale response, as well as free text answers to gather qualitative information. 3D scans of the scapula, humerus, radius, ulna, vertebrae and skull were successfully produced by SLS. Interactive models were produced via scan data in Sketchfab and successfully annotated to provide labelled 3D models for examination. 94% of survey respondents agreed that the interactive models were easy to use (n=35, 31% agree and 63% strongly agree) and 97% agreed that the 3D interactive models were more useful than 2D images for learning bony anatomy (n=35; 26% agree and 71% strongly agree). This initial study has demonstrated a suitable proof-of-concept for SLS technology as a useful technique for producing 3D interactive online tools for learning and teaching bony anatomy. Current studies are focussed on determining the SLS accuracy and the ability of SLS to capture soft tissue/joints. We believe that this tool will be a useful technique for generating online 3D interactive models to study orthopaedic anatomy

Universities have an obligation to ensure that Intellectual Property (IP) outputs are properly captured and exploited according to various National and European guidelines. There are two main ways which University technology development can take on the road to commercialisation: 1. Licensing the technology to an existing company: A license is permission to do something the granting party (the licensor) has the right to otherwise prohibit. In the context of IP licensing, it is a grant, by the owner of the property, to another (the licensee) of the right to use the IP in question for commercial purposes; 2. Starting a new company: An important university objective is to explore and pursue opportunities for the exploitation of its intellectual property rights. For universities and its inventors, spin out companies often provide an effective means to achieve this objective. A spin out is created when the University creates a new company out of one of its existing departments, institutions or by an inventor. The decision of which path to take is critical and various elements can effect this decision such as the inventors own objectives, the market niche for the technology, the stage of technical development, the potential reward for each option and the types of support structures available. This talk will summarise the main points to consider when deciding on the most appropriate way to commercialise technologies developed in Universities

Significance. Increasing health care costs are bankrupting the United States and other industrialized countries. To control and/or reduce costs in health care, hospitals, payers, and patients are turning to evidence-based meta-analyses and health economic analyses to identify medical treatments that provide value (value=outcome/cost). Objective: To determine if clinical outcome (patient reported outcomes) analyses or value/economic analyses are more likely to provide the evidence needed for adoption of new technologies in arthroplasty. Methods. A proprietary joint arthroplasty database of patient reported outcomes (PROs) was analyzed to determine the minimum clinically important differences (MCIDs) for PROs used for total knee replacement surgery. The PROs analyzed were: (1) European quality of life (EQ-5D); Oxford Knee Score (OKS); (3) Lower Extremity Activity Scale (LEAS); and (4) Likert Pain Scale (LPS). The MCID was calculated using a distribution method where the MCID equals one half the standard deviation of the score change, MCID = σΔ/2. For clinical meta-analyses, new technologies must demonstrate statistically significant better PROs and the difference must be greater than the MCID. For economic analyses, quality adjusted life years (QALYs) are used. For example, if a total knee replacement (TKR) improved a patient's health-related quality of life by 10% (0.10) and the assumed implant life is 15 years, the patient received 1.5 QALYs (0.10 × 15 years). If the total cost of care for the knee replacement surgery is $30,000, the cost per QALY is $20,000 ($30,000/1.5 QALYs). Results. The MCIDs for EQ-5D, OKS, LEAS, and LPS are 0.086%, 4.6 points, 1.6 points, and 1.3 points, respectively. The mean change (one-year post-operative EQ-5D minus pre-operative EQ-5D) for health-related quality of life is 15% (0.15). The average patient received 2.25 QALYs (0.15 × 15 years) from the surgery. The average cost per QALY is $13,333. However, if a new technology improves the mean health-related quality of life by 1% and the assumed implant life is 15 years, the patient receives 0.15 QALYs of improvement. With an average cost per QALY of $13,333, the new technology will be cost effective if the new technology cost is less than or equal to $2,000 (0.15 × $13,333) per patient. Conclusions. Achieving clinical superiority with new arthroplasty technology will be difficult because the minimum clinically important differences that need to be achieved are significant (EQ-5D 8.6%, OKS 4.6 points, LEAS 1.3 points, and LPS 1.3 points). However, small mean improvements in health-related quality of life (1%) can make the new technology cost effective. New technologies for arthroplasty surgery will increasingly need economic analyses to demonstrate cost effectiveness. Orthopaedic surgeons and manufacturers must collaborate to routinely collect health-related quality of life (EQ-5D) patient reported outcomes to provide a pathway for adoption of new innovative arthroplasty technologies

Objective. To analyze the short-term outcome after medial open-wedge high tibial osteotomy with a 3D-printing technology in early medial keen osteoarthritis and varus malalignment. Design and Method. 32 knees(28 cases) of mOWHTO (fixation with an angular-stable TomoFix implant(Synthes)) with a 3D-printing technology combined with arhtroscopy were prospectively surveyed with regard to functional outcome(Hospital for special knee score [HSS] score). Pre- and postoperative tibial bone varus angle (TBVA), mechanical medial proximal tibial angle (MPTA), and alignment were analyzed with regard to the result. Results. 32 knees were included (28 patients; mean age 46.5±9.3 years). The follow-up rate was 100% at 1.7±0.6 years (range, 1.2–3.2 years). Pre- and postoperative mechanical tibiofemoral axis were 6.8°±2°of varus and 1.2°± 3.4° of valgus, respectively. HSS score significantly improved from 46.0±18.3 preoperatively to 84±12 at one, 80±7 at two years (P<0.01). Conclusions. Medial open-wedge high tibial osteotomy with a 3D-printing technology combined with arthroscopy in medial keen osteoarthritis and varus malalignment is an accurate and good treatment option. High preoperative TBVA and appropriate corrected angle(0–3° of valgus)) was associated with better functional outcome at final follow-up

Production of porous titanium bone implants is a highly promising research and application area due to providing high osseointegration and achieving the desired mechanical properties. Production of controlled porosity in titanium implants is possible with laser powder bed fusion (L- PBF) technology. The main topics of this presentation includes the L-PBF process parameter optimization to manufacture thin walls of porous titanium structures with almost full density and good mechanical properties as well as good dimensional accuracy. Moreover, the cleaning and coating process of these structures to further increase osseointegration and then in-vitro biocompatibility will be covered

Introduction. Robotic-arm assisted knee arthroplasty (rKA) has been associated with improved clinical, radiographic, and patient-reported outcomes. There is a paucity of literature, however, addressing its cost effectiveness. In the context of an integrated health system with an insurance plan and single source comprehensive data warehouse for electronic health records and claims data, we present an evaluation of healthcare costs and utilization associated with manual knee arthroplasty (mKA) versus rKA. We also examine the influence of rKA technology on surgeons’ practice patterns. Methods. Practice patterns of KA were assessed 18 months before and after introduction of robotic technology in April 2018. For patients also insured through the system's health plan, inpatient costs (actual costs recorded by health system), 90-day postoperative costs (allowed amounts paid by insurance plan), and 90-day postoperative utilization (length of stay, home health care visits, rehabilitation visits) were compared between mKA and rKA patients, stratified by total (TKA) or unicompartmental (UKA) surgery. Linear regression modeling was used to compare outcomes between the two pairs of groups (mKA vs. rKA, for both UKA and TKA). Log-link function and gamma error distribution was used for costs. All analyses were done using SAS statistical software, with p<0.05 considered statistically significant. Results. Overall KA volume increased 21%, from 532 cases in the pre-rKA period to 644 post-rKA introduction, with UKA surgeries increasing from 38 to 97 (155%). Of these KAs, 218 patients were insured through our system's health plan (38 rUKAs, 9 mUKAs, 91 rTKAs, and 80 mTKAs), allowing precise insurance claims analysis for postoperative utilization and cost. Patients with rKA had significantly lower mean home health costs (-90% difference for UKA, −79% difference for TKA, p<0.02) and home rehab costs (-64% difference for UKA, −73% difference for TKA, p≤0.007) than mKA patients. No significant differences were observed in outpatient rehab (visits or costs), total rehab costs, or length of stay. Mean total postoperative costs were significantly lower for rUKA than mUKA (-47% difference, p=0.02) but similar for TKA (p>0.05). There were no significant differences in total inpatient costs between MAKO and non-MAKO patients. Conclusion. Robotic-arm assisted KA can allow for increased UKA volume and potential for substantial cost savings over the total episode of care by reducing postoperative utilization and costs

Osteoarthritis (OA) is a degenerative joint disease affecting millions worldwide. Early detection of OA and monitoring its progression is essential for effective treatment and for preventing irreversible damage. Although sensors have emerged as a promising tool for monitoring analytes in patients, their application for monitoring the state of pathology is currently restricted to specific fields (such as diabetes). In this study, we present the development of an optical sensor system for real-time monitoring of inflammation based on the measurement of nitric oxide (NO), a molecule highly produced in tissues during inflammation. Single-walled carbon nanotubes (SWCNT) were functionalized with a single-stranded DNA (ssDNA) wrapping designed using an artificial intelligence approach and tested using S-nitroso-N-acetyl penicillamine (SNAP) as a standard released-NO marker. An optical SWIR reader with LED excitation at 650 nm, 730 nm and detecting emission above 1000 nm was developed to read the fluorescence signal from the SWCNTs. Finally, the SWCNT was embedded in GelMa to prove the feasibility of monitoring the release of NO in bovine chondrocyte and osteochondral inflamed cultures (1–10 ng/ml IL1β) monitored over 48 hours. The stability of the inflammation model and NO release was indirectly validated using the Griess and DAF-FM methods. A microfabricated sensor tag was developed to explore the possibility of using ssDNA-SWCNT in an ex vivo anatomic set-up for surgical feasibility, the limit of detection, and the stability under dynamic flexion. The SWCNT sensor was sensitive to NO in both in silico and in vitro conditions during the inflammatory response from chondrocyte and osteochondral plug cultures. The fluorescence signal decreased in the inflamed group compared to control, indicating increased NO concentration. The micro-tag was suitable and stable in joints showing a readable signal at a depth of up to 6 mm under the skin. The ssDNA-SWCNT technology showed the possibility of monitoring inflammation continuously in an in vitro set-up and good stability inside the joint. However, further studies in vivo are needed to prove the possibility of monitoring disease progression and treatment efficacy in vivo. Acknowledgments: The project was co-financed by Innosuisse (grant nr. 56034.1 IP-LS)

Background. It is technically challenging to restore hip rotation center exactly in total hip arthroplasty (THA) for patients with end-stage osteoarthritis secondary to developmental dysplasia of the hip (DDH) due to the complicated acetabular morphology changes. In this study, we developed a new method to restore hip rotation center exactly and rapidly in THA with the assistance of three dimensional (3-D) printing technology. Methods. Seventeen patients (21 hips) with end-stage osteoarthritis secondary to DDH who underwent THA were included in this study. Simulated operations were performed on 3-D printed hip models for preoperative planning. The Harris fossa and acetabular notches were recognized and restored to locate acetabular center. The agreement on the size of acetabular cup and bone defect between simulated operations and actual operations were analyzed. Clinical and radiographic outcomes were recorded and evaluated. Results. The sizes of the acetabular cup of simulated operations on 3-D printing models showed a high rate of coincidence with the actual sizes in the operations(ICC value=0.930) There was no significant difference statistically between the sizes of bone defect in simulated operations and the actual sizes of bone defect in THA(t value=0.03 P value=0.97). The average Harris score of the patients was improved from (38.33±6.07) preoperatively to the last follow-up (88.61±3.44) postoperatively. The mean vertical and horizontal distances of hip rotation center on the pelvic radiographs were restored to (15.12 ± 1.25 mm and (32.49±2.83) mm respectively. No case presented dislocation or radiological signs of loosening until last follow-up. Conclusions. The application of 3-D printing technology facilitates orthopedists to recognize the morphology of Harris fossa and acetabular notches, locate the acetabular center and restore the hip rotation center rapidly and accurately

Decreasing the bulk weight without losing the biomechanical properties of commercial pure titanium (Cp-Ti) medical implants is now possible by using Laser Powder Bed Fusion (L-PBF) technology. Gyroid lattice structures that have precious mechanical and biological advantages because of similarity to trabecular bone. The aim of the study was to design and develop L-PBF process parameter optimization for manufacturing gyroid lattice Cp-Ti structures. The cleaning process was then optimized to remove the non-melted powder from the gyroid surface without mechanical loss. Gyroid cubic designs were created with various relative densities by nTopology. L-PBF process parameter optimization was progressed using with Cp-Ti (EOS TiCP Grade2) powder in the EOS M290 machine to achieve parts that have almost full dense and dimensional accuracy. The metallography method was made for density. Dimensional accuracy at gyroid wall thicknesses was investigated between designed and manufactured via stereomicroscope, also mechanical tests were applied with real time experiment and numerical analysis (ANSYS). Mass loss and strut thickness loss were investigated for chemical etching cleaning process. Gyroid parts had 99,5% density. High dimensional accuracy was achieved during L-PBF process parameters optimization. Final L-PBF parameters gave the highest 19% elongation and 427 MPa yield strength values at tensile test. Mechanical properties of gyroid were controlled with changing relative density. A minute chemical etching provided to remove non-melted powders. Compression test results of gyroids at numerical and real-time analysis gave unrelated while deformation behaviors were compatible with each other. Gyroid Cp-Ti osteosynthesis mini plates will be produced with final L-PBF process parameters. MTT cytotoxicity test will be characterized for cell viability. Acknowledgements This project is granted by TUBITAK (120N943). Feza Korkusuz MD is a member of the Turkish Academy of Sciences (TÜBA)

Background of Study. Identification of the exact make and model of an orthopaedic implant prior to a revision surgery can be challenging depending upon the surgeon's experience and available knowledge base about the available implants. The current identification procedure is manual and time consuming as the surgeon may have to do a comprehensive search within an online database of radiographs of an implant to make a visual match. There is further time lapse in contacting that particular implant manufacturer to confirm the make and model of the implant and then order the whole inventory for the revision surgery. This leads to delay in treatment thus requiring extra hospital bed occupancy. Materials and Methods. We have analysed image recognition techniques currently in use for image recognition to understand the underlying technologies based on an interface commonly known as Application Programming interface (API). These API's specifies how the software components of the proposed application interact with each other. The objective of this study is to leverage one or a combination of API's to design a fully functional application in the initial phase and that can help recognize the implant accurately from a large database of radiographs and then develop a specialized and advanced API/Technology in the implant identification application. Results. Our study takes into account the existent technologies such as Facebook, Pictoria, Imagga, Google images. We found that there is an API currently available that can be directly applied to build an implant recognition system. However, commonly known Facebook's image tagging algorithms to store unique information with each image is the starting point to help build an intelligent system that in combination with image processing and development of a custom implant recognition API. Conclusion. There is an urgent need to have a robust and accurate system for identification of orthopaedic implants. Revision surgeries may need to be carried out by hospitals without access to index surgery operating notes. Patients may approach the most convenient not necessarily the same surgeon for a revision surgery. The dependency upon surgeon's experience, hospitals facilities and archiving of records can be avoided with the use of a single application that allows multiple manufacturers to contribute to a database of catalogue of their products

Purpose. South African arthroplasty surgeons commonly make use of new bearing surface technology. This new technology only has short term, industry funded clinical trials or simulator studies available to prove its performance and motivate its use. These products are being used despite the availability of conventional components with proven long term in vivo efficacy. In the light of the recent Du Puy ASR recall, which also showed initial good clinical results, we reviewed the available data on some of the new available bearing surface technology. Methods. We performed a literature search to identify the best available clinical data regarding duration of follow up and number of patients for a selection of new bearing surfaces and compared it to well known long term clinical follow up studies and joint registry data of conventional products. Results. New bearing surface technologies have no long term clinical supportive data. Short and medium term results are available, however these are limited and mainly industry funded. Simulator data constituts the bulk of research used as motivation for the introduction of new technologies. Conclusion. The currently available data on new bearing surface technology is not adequate to provide the arthroplasty surgeon with a confident opinion on long term safety and efficacy. Surgeons should be careful when recommending new products to their patients, who are usually well informed of new technology but often without the necessary insight. NO DISCLOSURES

Total ankle replacement (TAR) is contraindicated in patients with significant talar collapse due to AVN and in these patients total talus body prosthesis has been proposed to restore ankle joint. To date, five studies have reported implantation of a custom-made talar body in patients with severely damaged talus, showing the limit of short-term damage of tibial and calcaneal thalamic joint surfaces. Four of this kind of implants have been performed. The first two realized with “traditional” technology CAD-CAM has been performed in active patients affected by “missing talus” and now presents a survival follow-up of 15 and 17 years. For the third patient affected by massive talus AVN we designed a 3D printed porous titanium custom talar body prosthesis fixed on the calcaneum and coupled with a TAR, first acquiring high-resolution 3D CT images of the contralateral healthy talus that was “mirroring” obtaining the volume of fractured talus in order to provide the optimal fit. Then the 3D printed implant was manufactured. The fourth concern a TAR septic mobilization with high bone loss of the talus. The “two-stage” reconstruction conducted with the implant of total tibio-talo-calcaneal prosthesis “custom made” built with the same technology 3D, entirely in titanium and using the “trabecular metal” technology for the calcaneous interface. Weightbearing has progressively allowed after 6 weeks. No complications were observed. All the implants are still in place with an overall joint mobility ranging from 40° to 60°. This treatment requires high demanding technical skills and experience with TAR and foot and ankle trauma. The 15 years survival of 2 total talar prosthesis coupled to a TAR manufactured by a CAD-CAM procedure encourages consider this 3D printed custom implant as a new alternative solution for massive AVN and traumatic missing talus in active patients

INTRODUCTION. Measurement of range of motion is a critical item of any knee scoring system. Conventional measurements used in the clinical settings are not as precise as required. Smartphone technology using either inclinometer application or photographic technology may be more precise with virtually no additional cost when compared to more sophisticated techniques such as gait analysis or image analysis. No comparative analysis between these two techniques has been previously performed. The goal of the study was to compare these two technologies to the navigated measurement considered as the gold standard. MATERIAL. Ten patients were consecutively included. Inclusion criterion was implantation of a TKA with a navigation system. METHODS. Two free angle measurement applications were downloaded to the Smartphone: one using inclinometer technology, the other using camera technology. After navigation assisted TKA and just before wound closure, the operated knee was positioned at full extension, 30±2°, 60±2°, 90±2° and 120±2° according to the navigated measurement. At each step, the knee flexion angle was measured with both Smartphone applications: inclinometer application (figure 1) and camera application (figure 2). For each of the ten patients, 5 navigated, 5 inclinometer and 5 camera measurements were obtained for each patient, giving three sets of 50 repeat measurements. The sample size was calculated to get a significance level of 0.05 and a power of 0.8 to detect a 10° difference. The difference between the three sets of measurements was analyzed with an ANOVA test for repeat measurements, with post-hoc comparisons with a paired Wilcoxon test. The correlation between the three sets of measurements was analyzed with a Kendall test, with post-hoc comparisons with a Spearman test. All tests were performed at a 0.05 level of significance, and post-hoc comparisons were performed at a 0.01 level of significance. RESULTS. The mean paired difference between navigated and camera measurements was 0.7° (SD 1.5°), with one difference greater than 3°. The mean paired difference between navigated and inclinometer measurements was 7.5° (SD 5.3°), with 16 differences greater than 10°. The mean paired difference between inclinometer and camera measurements was −6.8° (SD5.2°), with 7 differences greater than 10°. The ANOVA test for repeat measurements showed a significant difference between the three sets of measurements (p<0.001). The results of post-hoc paired comparisons with the Wilcoxon test are reported in table 2. The Kendall test showed that the distribution of the three sets of measurements was no different. The post-hoc paired correlations with the Spearman test showed a good coherence between all pairs of measurements (R² between 0.02 and 0.12). No pre-operative criteria showed a significant influence on the differences observed. DISCUSSION. Measuring the knee flexion angle with the camera of a smartphone is effective in a routine clinical practice. Accuracy can be better than other conventional measurement techniques. All applications of a smartphone do not have the same precision and must be validated before clinical use. CONCLUSION. Smartphone technology enables a more accurate assessment of the knee range of motion after TKA than conventional measurement techniques. To view tables/figures, please contact authors directly

Local anatomical abnormalities vary in congenital hip disease patients. Authors often present early to mid-term total hip arthroplasty clinical outcomes using different techniques and implants randomly on patients with different types of the disease, making same conclusions difficult. We report long term outcomes (13 to 23 years) of the treatment of low and high dislocation cases (separately) with total hip arthroplasty using TM technology acetabular cups (Implex initially and then Zimmer) and short fluted conical (Zimmer) femoral stems. From 2000 to 2010, 418 congenital hip disease hip joints were treated in our department with total hip arthroplasty. According to Hartofilakidis et al's classification, 230 hips had dysplasia, 101 low dislocation, (group A) and 87 high dislocation (group B). Pre-operative and post-operative values, at regular intervals, of HHS, SF-12, WOMAC, OHS and HOOS were available for all patients. Patient, surgeon and implant related failures and complications were recorded for all patients. In all cases an attempt was made to restore hip center of rotation. In group A the average lengthening was 2.8 cm (range: 1 to 4.2) and in group B 5.7 cm (range: 4.2 to 11). In both groups, no hips were revised due to aseptic loosening of either the acetabular cup or the femoral stem. In group A, a cumulative success rate of 95.6% (95% confidence interval, 92.7% – 97.4%) and in group B a cumulative success rate of 94.8% (95% confidence interval, 92.6%–96.9%) was recorded, at 20 years, with revision for any reason as an end point. No s.s. differences were found between groups when mean values of HHS, SF-12, WOMAC and OKS were compared. Satisfactory long-term clinical outcomes can be achieved in treating different types of congenital hip disease when appropriate surgical techniques combined with “game changing” implants are used

Aims. Complex joint fractures of the lower extremity are often accompanied by soft-tissue swelling and are associated with prolonged hospitalization and soft-tissue complications. The aim of the study was to evaluate the effect of vascular impulse technology (VIT) on soft-tissue conditioning in comparison with conventional elevation. Methods. A total of 100 patients were included in this prospective, randomized, controlled monocentre study allocated to the three subgroups of dislocated ankle fracture (n = 40), pilon fracture (n = 20), and intra-articular calcaneal fracture (n = 40). Patients were randomized to the two study groups in a 1:1 ratio. The effectiveness of VIT (intervention) compared with elevation (control) was analyzed separately for the whole study population and for the three subgroups. The primary endpoint was the time from admission until operability (in days). Results. The mean length of time until operability was 8.2 days (SD 3.0) in the intervention group and 10.2 days (SD 3.7) in the control group across all three fractures groups combined (p = 0.004). An analysis of the subgroups revealed that a significant reduction in the time to operability was achieved in two of the three: with 8.6 days (SD 2.2) versus 10.6 days (SD 3.6) in ankle fractures (p = 0.043), 9.8 days (SD 4.1) versus 12.5 days (SD 5.1) in pilon fractures (p = 0.205), and 7.0 days (SD 2.6) versus 8.4 days (SD 1.5) in calcaneal fractures (p = 0.043). A lower length of stay (p = 0.007), a reduction in pain (p. preop. = 0.05; p. discharge. < 0.001) and need for narcotics (p. preop. = 0.064; p. postop. = 0.072), an increased reduction in swelling (p < 0.001), and a lower revision rate (p = 0.044) could also be seen, and a trend towards fewer complications (p = 0.216) became apparent. Conclusion. Compared with elevation, VIT results in a significant reduction in the time to achieve operability in complex joint fractures of the lower limb. Cite this article: Bone Joint J 2021;103-B(4):746–754

Crosslinking has been already used for about 80 years to enhance the longevity of polyethylene cables. The polymer alteration has been achieved with peroxide, silane or irradiation. The medical devices industry discovered the benefit of this technology for its tribological applications like hip or knee bearings in the 2000s as crosslinking improves considerably the abrasion resistance of the material. The more current methods used are Gamma and Beta irradiation. On the basis of economical (rising prices of Cobalt), environmental (the radioactive source can not be turned off), technological (low dose rate) drawbacks for Gamma respectively low penetration for Beta irradiation we decided to investigate an alternative technology: the X-Ray irradiation, which provides a homogeneous crosslinking in a relatively short time. We analyzed the wear, mechanical, thermal, oxidative and network properties of two vitamin E doped UHMWPE: first crosslinked with E-Beam, second with X-Ray. There wasn't any significant difference between the X-Ray and the E-Beam crosslinked material

Shoulder arthroplasty has experienced exponential growth in the past 10–15 years, largely due to improvements in anatomical design, increased application of technology to address various clinical pathology, and improved access to experienced shoulder surgeons. Glenohumeral arthritis has historically been the most common indication for a shoulder replacement, and glenoid wear has been the main concern with regards to longevity of the prosthesis. Attempts to improve glenoid components involve alterations in peg or keel configuration, as well as the introduction of metal backed constructs. Early experience with metal backed components led to very poor results with often catastrophic loosening and destruction of glenoid bone. Proximal humerus fractures are another common indication for a shoulder arthroplasty, and in these cases, tuberosity fixation and healing are the challenge precluding a consistently successful result. More recently, base plate fixation in the setting of a reverse shoulder arthroplasty has come to the forefront as a significant factor. Trabecular metal technology has emerged as a compelling method of enabling powerful bone ingrowth to the surfaces of arthroplasty components. Trabecular metal is composed of tantalum. It is used to form a carbon scaffold which has a modulus between that of cancellous and cortical bone, thus has some flexibility when made into an independent construct. Vapor deposition onto arthroplasty surfaces provides a bone ingrowth surface. There is interest in utilizing trabecular metal for glenoid and tuberosity fixation in particular. Trabecular metal proximal coated stems provide an ingrowth surface for tuberosity fixation in the setting of proximal humerus fractures. Long term results are still pending. Because the metal is much less stiff then other metals, trabecular metal has recently been used along the back of polyethylene glenoids. The original design had a problem with fracture at the base of the pegs. A redesigned component instituting a cruciate design was implemented, and is currently available on a limited release basis with promising early results. The use of trabecular metal on the deep surface of the reverse arthroplasty baseplate and the proximal aspect of the reverse stem has led to successful fixation, allowing cementless fixation of both the humeral and glenoid components. Learning objectives of this presentation include:. Understand the mechanical characteristics of trabecular metal and its bone ingrowth characteristics. Familiarize with currently available prosthetics incorporating trabecular metal technology. Case presentations utilizing trabecular metal coated components

The plasma spray(TPS) has come to be accepted as one of the more reliable methods of porous coating of prosthesis, it is not without some technical limitations, especially with regard to precise modulation of pore size, porosity, and roughness. However, the plasma spray(TPS) not often but seriously faces problems such as bead detachment related poor osteointegration, weakness of metal strength and high manufacturing costs in addition to its various technical limitations. Currently, there has been much research into developing a more economical and effective method for porous coating of the prosthesis. In light of such demand, 3D Printing with DMT Technology has been introduced into the field of surface treatment of prosthesis with promising expectations. DMT technology -an additive fabrication process that uses high-power laser and various metal powders in order to produce fully dense and geometrically complex metal components, molds, and dies directly from digital CAD model data of 3D subjects aims to help overcome many of the problems associated with plasma spray and thereby open a new chapter of endless possibilities for coating technology. In this study, the porous coating specimen using 3-D DMT metal printing was characterized morphologically as well as biomechanically, in terms of 1) pore size 2) porosity 3) tensile strength 4) shear strength 5) roughness respectively. The biological cyto-compatibility was evaluated by culturing human osteoblast-like cells(Saos-2: ATCC HTB85) on the surface of round discs with porous coating to demonstrate the biological influence on the porosity of the specimens with different surface treatment for comparative analysis. The evaluation was accompanied by assessment of cell proliferation and morphology with arrangement of actin filament and expression of adhesion molecule with α. v. β. 3. integrin. While 3-D DMT coating specimen showed relatively regular porosity in the range of 150–500µm with the increase of porosity about 83%, the mechanical behavior remarkably improved, compared to TPS: shear strength 13%, fatigue failure 30%, roughness 16%, respectively. Also worth noting, the tensile strength was unable to be measured because the glue for test had fallen off. (Fig. 1) There is no transitional zone underneath the porous coating layer.(Fig. 2) From the aspect of biocompatibility, 3-D coating showed better cell attachment, spreading of cytoskeleton, cell proliferation, and expression of osteogenic markers than TPS, even if not significantly.(Fig. 3) Additionally, cell migration assay was performed with double chamber study, and gene expression was evaluated by measuring alkaline phosphatase(ALP) levels and analyzing mRNA expression for ostepontin(OPG) and osteocalcin(OC). In conclusion, the study reinforces the popular stance that the implementation of 3-D DMT could open up new possibilities for coating technology and form a new chapter in the history of prosthesis development

Biological fixation of arthroplasty devices through osseointegration via ingrowth or ongrowth can be achieved with a numerous surface treatments and technologies. Surface roughness and topography have evolved to include sintered bead, calcium phosphate coatings and more recently additive manufacturing techniques. Regardless of the technique employed, the clinical goal has always been directed at improving osseointegration and achieve rapid, stable and long-term implant fixation without compromising the mechanical properties of the device. Pre-clinical models provide insight into the in-vivo efficacy. The in vivo results of a wide range of technologies over the past 20 years have been examined by our laboratory using an adult ovine cortical and cancellous implantation model. This paper will present a twenty year experience of pre-clinical evaluation of bone ingrowth and ongrowth surfaces used for arthroplasty device fixation. The endpoints as well as understanding of the dynamic nature of the bone-implant interface continues to evolve as advanced manufacturing moves forward and the demands on the interface due to patient and surgeon expectations increase

Rural surgical practice in Australia provides a unique environment to the Orthopaedic Surgeon. Whilst most of the work load mimics that of city practice, the rural surgeon has little choice but to master a broad schema of surgical skills, and keeping up with the current literature and techniques can be challenging. At our public hospital over the last audited twelve month period, 108 primary total knee replacements were performed by 4 surgeons out of 236 joint replacements including revision surgeries. At the Private hospital a total of 215 joint replacements were performed in the same period including revision surgeries, of which 127 were knee arthroplasties. It is recognised that the incidence of complications from arthroplasty can be increased in low volume joint replacement surgeons. This centre is a mid volume centre, but rural and generally underfunded. In light of this, it is not unreasonable to look at techniques or evolving technologies that may improve the ability of an individual surgeon to position a joint replacement in an optimal position and with economic consideration. Conventional navigation has a number of factors associated with it that may make its use in a rural centre less attractive. These include capital cost of both hardware and software; Most rural centres do not have the ability to purchase the hardware and thus the issue of transporting hard ware on site, and representative support, may all be issues. The potential benefit of patient specific implants [PSI] may thus be two-fold in this setting. The surgeon and the patient benefit from the technology, but the technology does not need to be transported to the site. As a result of these considerations, a single surgeon in a rural centre, commenced using PSI's after gaining initial experience with the implant using traditional techniques. This early study looks at this experience and attempts to quantify some of the issues around this technology

Metal-polycarbonate urethane (MPU) bearing is a cutting-edge new bearing technology for hip reconstruction. It consists of a 3mm-thick pliable acetabular cup which biomechanically mimics human cartilage and can be coupled with large diameter metal heads. In pristine sockets, no acetabular bone reaming is required to insert the cup. No cement is needed and the cup is simply snapped by hand into a groove made with a special tool. In deformed sockets, the standard reaming technique must be used. The cup acts as a liner inserted into an uncemented metal shell. MPU bearing has been analysed in comparative in vitro studies. Clinical and radiographic results have been recorded at a minimum follow-up of 2 years in 202 femoral neck fracture patients. Polycarbonate-urethane elasticity is 20MPa (70 times less than UMHWPE, 10,500 times less than CoCr, p < 0.001). The number of particles generated per step is 1000 with MPU, 1,000,000 with ceramic-ceramic and metal-metal (MOM) (p< 0.001). Fluid film thickness is 0.25microns with MPU, 0.02 with MOM (p< 0.001). At a minimum follow-up of 2 years, X-rays showed good implant stability. In sockets where the buffer alone was implanted an improvement of the supraacetabular bone density was observed over time. Mean Harris hip score after 1 month was 58 points, increasing to 80 points at 2 years (p < 0.05). One patient was revised, due to non-implant-related pain. The in vitro and clinical data support the use of this novel bearing technology which has the potential to revolutionize hip arthroplasty

Wireless technologies applied to the medical field have grown both in prevalence and importance in the past decade. Various applications and technologies exist underneath the telemedicine umbrella including Point-of-Care systems where electrocardiographs, blood pressure, temperature, and medical image data are recorded and transmitted wirelessly, which enables remote patient monitoring from inside hospitals, personal residences, and virtually any location with access to satellite communication. Another widespread application for wireless systems in hospitals is asset tracking, typically done with RFID technology. Wireless technologies have not been widely used in computer assisted orthopaedic surgery (CAOS) because of the limitations in terms of overall 3-D accuracy. We have developed a wireless positioning system based on ultra wideband technology (UWB) which achieves mm-range 3-D dynamic accuracy and can be used for intraoperative tracking in CAOS systems. Current intraoperative tracking technologies include optical and electromagnetic tracking systems. The main limitations with these systems include the need for line-of-sight in optical systems and the limited view volume and susceptibility to metallic interference in electromagnetic tracking systems. UWB indoor positioning does not suffer from these effects. Until this point, the main limitation of UWB indoor positioning systems was its limitation in 3-D real-time dynamic accuracy (10–15 cm as opposed to the required 1–2 mm). We have developed a UWB indoor positioning system which achieves dynamic 3-D accuracy in the range of 5–6 mm for a non-coherent approach and 0.5–1 mm for a coherent approach (transmitter and receiver use the same clock signal). The integration of this tracking system with smart surgical tools opens up a plethora of exciting intraoperative applications including picking landmarks, 3-D bone and instrument registration, real-time wireless pressure sensing used for ligament balancing in TKA, and real-time A-mode ultrasound bone morphing. The UWB tracking system will be presented along with its integration into smart surgical tools and surgical navigation

The use of 3D imaging methodologies in orthopaedics has allowed the introduction of new technologies, such as the design of patient-specific implants or surgical instrumentation. This has introduced the need for high accuracy, in addition to a correct diagnosis. Until recently, little was known about the accuracy of MR imaging to reconstruct 3D models of the skeletal anatomy. This study was conducted to quantify the accuracy of MRI-based segmentation of the knee joint. Nine knees of unfixed human cadavers were used to compare the accuracy of MR imaging to an optical scan. MR images of the specimens were obtained with a 1.5T clinical MRI scanner (GE Signa HDxt), using a slice thickness of 2 mm and a pixel size of 0.39 mm × 0.39 mm. Manual segmentation of the images was done using Mimics® (Materialise NV, Leuven, Belgium). The specimens were cleaned using an acetone treatment to remove soft-tissue but to keep the cartilage intact. The cleaned bones were optically scanned using a white-light optical scanner (ATOS II by GOM mbH, Braunschweig, Germany) having a resolution of 1.2 million pixels per measuring volume, yielding an accuracy of 0.02 mm. The optical scan of each bone reflects the actual dimensions of the bone and is considered as a ground truth measurement. First, a registration of the optical scan and the MRI-based 3D reconstruction was performed. Then, the optical scan was compared to the 3D model of the bone by calculating the distance of the vertices of the optical scan to the reconstructed 3D object. Comparison of the 3D reconstruction using MRI images and the optical scans resulted in an average absolute error of 0.67 mm (± 0.52 mm standard deviation) for segmentation of the cartilage surface, with an RMS value of circa twice the pixel size. Segmenting the bone surface resulted in an average absolute error of 0.42 mm (± 0.38 mm standard deviation) and an RMS error of 1.5 times the pixel size. This accuracy is higher than reported previously by White, who compared MRI and CT imaging by looking at the positioning of landmarks on 3D printed models of the segmented images using a calliper [White, 2008]. They reported an average accuracy of 2.15 mm (± 2.44 mm) on bone using MRI images. In comparison, Rathnayaka compared both CT- and MRI-based 3D models to measurements of the real bone using a mechanical contact scanner [Rathnayaka, 2012]. They listed an accuracy of 0.23 mm for MRI segmentation using five ovine limbs. This study is one of the first to report on the segmentation accuracy of MRI technology on knee cartilage, using human specimens and a clinical scanning protocol. The results found for both bone and cartilage segmentation demonstrate the feasibility of accurate 3D reconstructions of the knee using MRI technology

Although metal-on-metal hip resurfacing (MOMHR) is becoming a well accepted indication for young active patients with hip deformities, it does not come without its disadvantages. Longterm bone atrophy, serum metal ion elevation, metal ion hypersensitivity and the formation of pseudotumours have all been reported in the literature. It is thus clear that there is a need for novel bearing technology. A potentially revolutionary hip resurfacing system comes in the form of the TriboFit. ®. Hip System, which comprises a 2.7 mm-thick acetabular buffer made of polycarbonate-urethane, a hydrophilic, biocompatible, endotoxin-resistant material which mimics the fluid film layer naturally present in hip joints. This is a pliable implant whose modulus of elasticity is the same as that of normal human cartilage, thus providing optimum shock absorption. In addition, it induces lubrication, which is of the utmost importance as friction is almost eliminated, resulting in a subsequent decrease in the production of wear particles. Indeed, in vitro studies have shown that metal wear is 7-fold less than with a comparable metal-on-metal implant. The TriboFit. ®. Buffer is implanted using flexible mechanical fixation. With a special instrument, a circumferential groove is cut into the patients’ socket. The TriboFit. ®. Buffer is seated by applying gentle pressure, with its ledge snapping tightly into the groove. The surgical technique is bone sparing as no acetabular bone reaming is required whatsoever. The TriboFit. ®. Buffer can be coupled with a select number of metal hip resurfacing femoral components. In our centre, we have used this novel bearing technology to treat patients with both osteoarthritis (two patients) and avascular necrosis (four patients). The mean patient age was 50 years (range 30 to 63). In five patients who had a well preserved socket anatomy, the TriboFit. ®. Buffer was implanted without reaming the acetabular bone. In one patient with significant osteoarthritic changes of the socket, the TriboFit. ®. Buffer was inserted into a specially manufactured uncemented metal shell, using the TriboFit. ®. Buffer as a liner. The socket was reamed according to the standard reaming technique. In two patients a Birmingham hip resurfacing (BHR) femoral component was used and in the other four an ADEPT component was used. Rehabilitation was fast and uncomplicated. The mean follow-up of these patients was one year. The mean preoperative Harris hip score (HHS) was 62. The mean HHS at one year was 99 (p = < 0.05). X-rays showed good quality bone at the bone-implant interface. No osteolysis, loosening, or bone rarefaction was observed. At follow-up, two patients resumed sporting activities. One patient resumed skiing while the other resumed biking. Our pilot study shows that TriboFit. ®. Buffer hip resurfacing arthroplasty is a valid alternative to MOMHR. Compared to the latter, the major advantage includes significantly lower metal wear generation, without any differences in the functional results. This new technology has the potential to expand the use of hip resurfacing to patients with renal malfunction, metal ion allergy/hypersensitivity and to fertile females

Purpose: Few opportunities exist for physicians to easily obtain immediate insights or solicit direct advice from a respected peer on a complicated case. As a result, physicians end up relying heavily on journals, textbooks, and other dated resources that may prove to be dated or inadequate in addressing unique patient problems. Furthermore, the typical training modules available are limited to a one- or two-day experience. Often times this situation does not provide an adequate understanding of the surgical indications, techniques, and potential complications in the application of new technology. Consequently, many surgeons fail to adopt new technologies due to their lack of understanding of the application of such novel technologies. Recently, Reynolds et al studied the effect of peer collaboration among surgeons at a weekly surgery conference. They found that changes in surgical decision-making occurred in 12.5% of all cases reviewed and in 20% of the complex cases. However, collaboration should not be limited to weekly meetings or annual conferences. The Internet has introduced Collaborative Knowledge Networks (CKNs) that allow communities of surgeons to collaborate virtually on complex patient cases—allowing for rapid, bidirectional information. SpineConnect has surfaced as an example of a CKN that allows orthopedic spine surgeons to discuss surgical decisions. Method: We studied the use of Internet collaboration among spine surgeons using the SpineConnect website. We also compared the improvement in the adoption rate of novel technologies using technology fellowships versus traditional training modules. These fellowships use both in-person and virtual collaboration through the Spine-Connect platform as a new means of training physicians. Results: Using the SpineConnect website, surgical decision-making and planning was altered in 34% of active users and 90% agreed that the ability to collaborate with their peers, using a dedicated website, has improved their ability to practice spinal surgery. Continuous communication and dialogue resulting from the technology training fellowships encouraged better understanding of surgical indications, a greater comprehension of surgical technique, and a mechanism to discuss and solve complications. When such fellowships were implemented, we found a 30% improvement in adoption rate over traditional training modules. Conclusion: The treatment of spine surgery patients has benefited from the utilization of collaborative platforms such as SpineConnect. In spine surgeon training and education, we found that CKNs promoted better surgical decision-making and increased understanding of new technology application

Purpose. The purpose of this study was to assess the accuracy of three-dimensional camera technology when monitoring deformity correction by an Ilizarov frame and to compare it to manual measurements. Methods and Results. A model consisting of an Ilizarov frame built around an artificial tibia and fibula was used with retro-reflective markers placed on the frame and bones to allow for the positions of each to be detected by the camera system. Measurements made by the camera system were compared to measurements taken manually. In the assessment of frame lengthening, the camera system average error was 2% (SD 2%) compared to 7% (SD 6%) for manual measurement. In the assessment of bone lengthening, the camera system average error was 4% (SD 4%) compared to 34% (SD 8%) for manual measurement. The technology also demonstrated good accuracy in the measurement of angular deformity changes. Conclusion. The results of this study demonstrate that the measurement of deformity correction with three-dimensional infra-red camera technology is superior to manual measurements in a model of deformity correction. This method could replace or greatly reduce x-ray exposure in monitoring deformity correction post-operatively

Introduction. The most common bearing couple used in total knee arthroplasty (TKA) is ultra-high molecular weight polyethylene (UHMWPE) articulating against a CoCrMo alloy femoral component. Although this couple has demonstrated good clinical results, UHMWPE wear has been identified as one of the principal causes for long-term failure of total knee joint replacements. 1. indicating a need for improvements in TKA bearings technology. The wear resistance of UHMWPE can be improved by radiation crosslinking; however, in order to get the full benefit of this improved wear resistance, an abrasion resistant ceramic counterface is necessary. 2. Since the radiation crosslinking degrades mechanical properties, it is also important to have an optimized radiation dose and subsequent processing. The purpose of this study was to evaluate the long-term wear performance of VERILAST Technology comprising two advanced bearing technologies, abrasion resistant OXINIUM femoral components (OxZr). 3-4. and wear/strength optimized 7.5 Mrad crosslinked polyethylene (7.5-XLPE). 5. Materials and Methods. Three component assemblies of LEGION(tm) cruciate retaining (CR) OxZr femoral components, 7.5-XLPE tibial inserts were tested on an AMTI knee simulator under displacement control at 1 Hz frequency as described previously. 2. The tibial inserts were manufactured from compression molded GUR 1020 UHMWPE, radiation crosslinked to 7.5 Mrad dose, remelted to extinguish free radicals, and sterilized by EtO. The wear test was conducted for 45 Mcycle, which was considered to be a conservative estimate for the amount of cycles that would occur during 30 years of typical in-vivo use based on the relationship between patient age and the number of loading cycles as reported in the literature. 6-8. Results. The predominant wear feature on the 7.5-XLPE inserts was burnishing. There were no signs of fatigue wear or delamination. The mean volumetric wear rate (± SD) of the 7.5-XLPE inserts articulating against OxZr femoral components for 45 Mcycle was 0.58±0.17 mm. 3. /Mcycle. In a previous wear test under substantially identical conditions for 5 Mcycle simulating approximately 3 years of use, the mean volumetric wear rate of CoCr and virgin UHMWPE (CPE) couples was 23.4±2.4 mm. 3. /Mcycle. 2. The mean volumetric wear rate of the OxZr/7.5-XLPE couples was approximately 98% lower compared to the CoCr/CPE couples (p<0.01). After simulating 3 years of use, the mean volumetric wear of OxZr/7.5-XLPE couples (2.67 mm. 3. ) was approximately 98% lower than CoCr/CPE couples (120.42 mm. 3. ) (Figure 1). Furthermore, after simulating 30 years of use, the mean volumetric wear of OxZr/7.5-XLPE couples (22.78mm. 3. ) was approximately 81% lower than the CoCr/CPE couples after simulating 3 years of use (120.42 mm. 3. ) (Figure 2). Discussion. This study demonstrates that coupling OxZr femoral components with 7.5-XLPE inserts results in a TKA bearing combination that provides and maintains significantly lower, long-term wear performance

Introduction:. Cam type femoroacetabular impingement (FAI) may lead to osteoarthritis (OA)[1]. In 2D studies, an alpha angle greater than 55° was considered abnormal however limitations of 2D alpha angle measurement have led to the development of 3D methods [2–4]. Failure to completely address the bony impingement lesions during surgery has been the most common reason for unsuccessful hip arthroscopy surgery [5]. Robotic technology has facilitated more accurate surgery in comparison to the conventional means. In this study we aim to assess the potential application of robotic technology in dealing with this technically challenging procedure of cam sculpting surgery. Methods:. CT scans of three patients' hips with severe cam deformity (A, B and C models) were obtained and used to construct 3D dry bone models. A 3D surgical plan was made in custom written software. Each 3D plan was imported into the Acrobot Sculptor robot and bone resection was carried out. In total, 42 femoral models were sculpted (14/subset), thirty of which were performed by a single operator and the remaining 12 femurs were resected by two other operators. CT of the pre/post resected specimens was segmented and a 3D alpha angle and head neck ratios were measured [3–4] and compared using Mann-Whitney U test. Coefficient of variation (CV) was used to determine the degree of variation between the mean and maximum observed alpha angles for inter and intra observer repeatability. Results:. The maximal alpha angle in cam A, B and C (90.8°, 91.3° and 87.1°). There was significant reduction (p < 0.001) in maximum alpha angles post-operatively within all three models when compared to original model (Figure 1). The HNRs for cam A, B and C prior to surgery were found to be 3.2, 3.4 and 3.1 respectively that were reduced to a mean of 3.0 ± 0.1, 3.1 ± 0.1 and 3.1 ± 0.0, following resection surgery. The results of the intra and inter-observer repeatability study found good reproducibility (CV<10%) of the maximum and mean alpha angles between the 12 resected femurs. Discussion:. In this study we evaluated the use of robotic system to perform cam correction surgery by evaluating the 3D morphology of head/neck prior to and post surgery. With existing surgical options there is a potential for under or over-resection of the cam lesion, which runs the risk of the need for further surgery or rarely neck fracture and dislocation. Based on the calculated alpha angles and HNRs we have proved that we have successfully performed the surgery by avoiding under and over resection respectively. Amore accurate bony resection performed here may minimize the complications due to over and under resection and hence will decrease the burden on the health service

Background. Dislocation is a common complication after proximal and total femur prosthesis reconstruction for primary bone sarcoma patients. Expandable prosthesis in children puts an additional challenge due to the lengthening process. Hip stability is impaired due to multiple factors: Resection of the hip stabilizers as part of the sarcoma resection: forces acts on the hip during the lengthening; and mismatch of native growing acetabulum to the metal femoral head. Surgical solutions described in literature are various with reported low rates of success. Objective. Assess a novel 3D surgical planning technology by use of 3D models (computerized and physical), 3D planning, and Patient Specific Instruments (PSI) in supporting correction of young children suffering from hip instability after expandable prosthesis reconstruction following proximal femur resection. This innovative technology creates a new dimension of visualization and customization, and could improve understanding of this complex problem and facilitate the surgical decision making and procedure. Method. Two children, both patients with Ewing Sarcoma of the left proximal femur stage-IIB, ages 3/5 years at diagnosis, were treated with conventional chemotherapy followed by proximal femur resection. Both were reconstructed with expandable prosthesis (one at resection and other 4 years after resection). Hip migration developed gradually during lengthening process in the 24m follow up period. 3D software (Mimics, Materialise, Belgium) were used to make computerized 3D models of patients' pelvises. These were used to 3D print 1:1 physical models. Custom 3D planning software (MSk Lab, Imperial College London) allowed surgeons visualizing the anatomical status and assess of problem severity. Thereafter, osteotomies planes and the desired position of acetabular roof after reduction of hip joint were planned by the surgeons. These plans were used to generate 3D printed PSIs to guide the osteotomies during shelf and triple osteotomy surgeries. Accuracy of planning and PSIs were verified with fluoroscopy and post-op X-rays, by comparing cutting planes and post-op position of the acetabulum. Results. Surgeons reported excellent experience with the 3D models (computerized and physical). It helped them in the decision process with an improved understanding of the relationship between prosthesis head and acetabulum, a clear view of the osteophytes and bone formation surrounding the pseudoacetabulum, and osteophytes inside the native acetabulum. These osteophytes were not immediately visible on 2D CT imaging slices. Surgeons reported a good fit and PSIs' simplicity of use. The hip stability was satisfactory during surgery and in the immediate post-op period. X-ray showed a good and centered position of the hip and good levels of the osteotomies. Conclusions. 3D surgical planning and 3D printing was found to be very effective in assisting surgeons facing complex problems. In these particular cases neither CT nor MRI were able to visualize all bony formation and entrapment of prosthesis in the pseudoacetabulum. 3D visualisation can be very helpful for surgical treatment decisions, and by planning and executing surgery with the guidance of PSIs, surgeons can improve their surgical results. We believe that 3D technology and its advantages, can improve success rates of hip stability in this unique cohort of patients

This study evaluates high power low frequency ultrasound transmitted via a flat vibrating probe tip as an alternative technology for meniscal debridement in the knee. A limitation of this technology is thermal damage in residual meniscal tissue. To compare tissue removal rate and thermal damage for a radiofrequency ablation device and an experimental ultrasound ablation device. Twelve bovine meniscal specimens were treated in an identical fashion with (a) a 3.75mm 50° bipolar radiofrequency wand, Arthrocare Super Multivac 50 Arthrowand (Arthrocare Corporation, Sunnyvale, CA), operated in a free-hand manner in accordance with manufacturers instructions (n=6), and (b) an experimental flat-tipped 3mm 20kHz ultrasound probe, suspended vertically in a 500N force-controlled experimental rig (n=6). Tissue removal rate (TRR), zone of thermal necrosis and zone of thermal alteration were calculated. Histological sections were prepared for each sample (H&E). Independent samples t-test was used to compare TRR, zone of thermal necrosis and zone of thermal alteration. Statistical analysis was performed using PASW Statistics (v.18, IBM SPSS Statistics, Chicago, IL, U.S.A.). The mean TRR for meniscal debridement by the radiofrequency device was 5.59±1.1mg/s. This compared with a mean TRR of 4.74±1.4mg/s for debridement with the ultrasound device at settings (p=0.259, NS). Mean depth of tissue removal using the radiofrequency device was 2.21±0.26mm compared to 3.75±0.25mm (p< 0.001, ?. 2. =0.09). Using the radiofrequency device, the mean depth of zone of thermal alteration was 1282±436µm, compared with 710±251µm for the force-controlled ultrasound device (p=0.29, ?. 2. =0.42). For the radiofrequency device, the mean depth of zone of thermal necrosis was 64±41µm versus 97±44µm for the ultrasound device (p=0.239, NS). We observed a trend towards an increased zone of thermal necrosis and a reduced zone of thermal alteration for the ultrasound device, when compared with the radiofrequency device. Ultrasonic debridement shows comparable thermal damage to existing radiofrequency meniscal debridement technology

Acetabular cup placement in total hip replacement surgery is often difficult to assess, especially in the lateral position and using the posterior approach. On table control X-Rays are not always accessible, especially in the government sector. Conventional techniques and computer assisted surgery (CAS), are currently the two most popular methods for proper placement of the acetabular cup in Lewinnek's safe zone of orientation (anteversion 15°–10° and lateral inclination 40°±10°). We developed a simple way to get accurate cup placement using Smartphone technology. Methods:. A spirit level application was downloaded to the Smartphone. The acetabulum inclination was measured on the pre-operative X-Rays. The phone is placed in a sterile bag and then used intra-operatively, to measure and set our acetabular cup orientation to our pre-operative measurements. The inclination level was measured before and after final placement of the acetabular cup. This was compared to the acetabular cup inclination in our post-operative X-Rays. Results:. In our series of 50 cup placements we found high accuracy. The results show less than 5° deviation between our pre-, intra- and post-operative measurements. Conclusions:. Smartphone technology proves to be good alternative to conventional methods and CAS, to improve Acetabular Cup placement in Total Hip Arthroplasty

Introduction: Improved biomechanics and stem fit facilitated by gender adepted dual stems and modularity has the potential to make THA easier and thereby decrease the complication rate. Increased fretting wear at the connecting interfaces may be a drawback. 10 year survival exceeding 90% is required to endorse modular necks and dual stem gender technology. Materials and Methods: We followed the first 190 consecutive implantations of an uncemented, straight femoral stem with dual stem technology and modular necks (European Hip System (EHS)/Profemur E, Wright Medical Technology Inc., Arlington, TN, USA) and a grit blasted titanium acetabular cup with a ceramic on polyethylene bearing in 178 patients from 1992 to 1997. Mean time of follow-up evaluation was 10 (8–13) years. Titanium serum ion levels were measured to detect fretting in the metal connection. Results: At follow-up, 21 patients (22 hips, 11.6%) had died, and 13 (14 hips, 7.4%) were lost to follow-up. One hip underwent femoral revision for a periprosthetic fracture. Overall stem survival was 99 (98–100) % at 10 years, survival with femoral revision for aseptic loosening as an end point was 100 (99–100) % at 10 years. Three acetabular components were revised, one for infection and two for aseptic loosening of the titanium shell. There was one fracture of a high offset modular neck at the laser labeling without trauma; the design was changed subsequently. The mean Harris-Hip-Score at follow-up was 88 points. 153 hips were available for radiolographic evaluation. No case of femoral or acetabular osteolysis or loosening was found. Accelerated wear was not detected on radiographs. No dislocation was found during the study period. The results showed no increased titanium serum ion levels compared to an age matched control group. Conclusions: The complication rate with this uncemented modular gender hip system was extremely low with a high patient (and surgeon) satisfaction. The modular neck system as well as the dual stem technology proved to be reliable. The metal ion analysis revealed no elevated serum ion levels. Modular necks and dual gender stems are a reliable and durable option in primary total hip arthroplasty

Objectives. Bioresorbable orthopaedic devices with calcium phosphate (CaP) fillers are commercially available on the assumption that increased calcium (Ca) locally drives new bone formation, but the clinical benefits are unknown. Electron beam (EB) irradiation of polymer devices has been shown to enhance the release of Ca. The aims of this study were to: 1) establish the biological safety of EB surface-modified bioresorbable devices; 2) test the release kinetics of CaP from a polymer device; and 3) establish any subsequent beneficial effects on bone repair in vivo. Methods. ActivaScrew Interference (Bioretec Ltd, Tampere, Finland) and poly(L-lactide-co-glycolide) (PLGA) orthopaedic screws containing 10 wt% β-tricalcium phosphate (β-TCP) underwent EB treatment. In vitro degradation over 36 weeks was investigated by recording mass loss, pH change, and Ca release. Implant performance was investigated in vivo over 36 weeks using a lapine femoral condyle model. Bone growth and osteoclast activity were assessed by histology and enzyme histochemistry. Results. Calcium release doubled in the EB-treated group before returning to a level seen in untreated samples at 28 weeks. Extensive bone growth was observed around the perimeter of all implant types, along with limited osteoclastic activity. No statistically significant differences between comparative groups was identified. Conclusion. The higher than normal dose of EB used for surface modification did not adversely affect tissue response around implants in vivo. Surprisingly, incorporation of β-TCP and the subsequent accelerated release of Ca had no significant effect on in vivo implant performance, calling into question the clinical evidence base for these commercially available devices. Cite this article: I. Palmer, S. A. Clarke, F. J Buchanan. Enhanced release of calcium phosphate additives from bioresorbable orthopaedic devices using irradiation technology is non-beneficial in a rabbit model: An animal study. Bone Joint Res 2019;8:266–274. DOI: 10.1302/2046-3758.86.BJR-2018-0224.R2

Introduction. 3-D Printing with direct metal tooling (DMT) technology was innovatively introduced in the field of surface treatment of prosthesis to improve, moreover to overcome the problems of plasma spray, hopefully resulting in opening the possibility of another page of coating technology. We presumed such modification on the surface of Co-Cr alloy by DMT would improve the ability of Co-Cr alloys to osseointegrate. Method. We compared the in vitro and in vivo ability of cells to adhere to DMT coated Co-Cr alloy to that of two different types of surface modifications: machined and plasma spray(TPS). We performed energy-dispersive x-ray spectroscopy and scanned electron microscopy investigations to assess the structure and morphology of the surfaces. Biologic and morphologic responses to osteoblast cell lines of human were then examined by measuring cell proliferation, cell differentiation (alkaline phosphatase activity), and avb3 integrin. The cell proliferation rate, alkaline phosphatase activity, and cell adhesion in the MAO group increased in comparison to those in the machined and grit-blasted groups. Results. The cell proliferation rate, alkaline phosphatase activity, and cell adhesion in the DMT group increased in comparison to those in the machined and TPS groups. Cell proliferation, alkaline phosphatase activity, migration, and adhesion were increased in DMT group compared to the two other groups. Human Osteoblast cells on DMT-coated surface were strongly adhered, and proliferated well compared to those on the other surfaces. Discussion. The surface modifications of DMT coating enhanced the biocompatibility (proliferation and migration of osteoblastlike cells) of Co-Cr alloy. This process is not unique to Co-Cr alloy; it can be applied to many metals to improve their biocompatibility, thus allowing a broad range of materials to be used for cementless implants

Background: The rates of primary and revision knee arthroplasty in the United States have been increasing. Simultaneously, several studies have reported increased complication rates when these procedures are performed at low-volume centers. One innovation designed to improve knee arthroplasty outcomes is computer navigation, which aims to reduce revision rates by improving the alignment achieved at surgery. The purpose of this study was to examine the impact of hospital volume on the costeffectiveness of this new technology in order to determine its feasibility and the level of evidence that should be sought prior to its adoption. Methods: A Markov decision model was used to evaluate the cost-effectiveness of computer-assisted knee arthroplasty, in relation to hospital volume. Transition probabilities were estimated from the arthroplasty literature, and costs were based on the average reimbursement for primary and revision knee arthroplasty at out institution. Outcomes were measured in quality adjusted life years. Results: The results demonstrate that computer-assisted surgery becomes less cost-effective as the annual hospital volume decreases, as the cost of navigation increases, and as the impact on revision rates decreases. If a center performs 250 cases per year, computer navigation will be cost-effective if the annual revision rate is reduced by 2% per year over a twenty-year period. If a center performs 150 cases per year, computer navigation is cost-effective if it results in a 2.5% reduction in the annual revision rate over a twenty-year period. If a center performs only 25 cases per year, the annual reduction in revision rates must be 13% for computer navigation to be cost-effective. Conclusion: This analysis demonstrates that computer navigation is not likely to be a cost-effective investment in health care improvement in low volume joint replacement centers, where its benefit is most likely to be realized. However, it may be a cost-effective technology for higher volume joint replacement centers, where the decrease in the rate of knee revision needed to make the investment cost-effective is modest, if improvements in revisions rates with the use of this technology can be realized. This illustrates that hospital volume can have a substantial impact on the cost-effectiveness of new technology in surgery, and this should be carefully considered by any center considering such a large capital investment

Football player's performance during competitive matches greatly depends on fitness and training. The use of GPS (Global Positioning System) has been revolutionary in the monitoring of player intensity during training. The aim of the study was to investigate the difference in training intensity between defenders, midfielders and forwards and if injury sustained was directly related to the intensity of training. GPS (Catapult Minimax GPS 10Hz) was used to collect training data for a professional British football club playing in the Championship, for the year August 2011/April 2012. Each player wore a GPS unit during each training session and the raw data was logged. The GPS calculates the player load which is a measure of intensity of training. It is a summation of instantaneous change of forward, sideway and upward accelerations. Adjustments are made for match days and injuries according to a defined set of rules. A total player load was obtained for each month and at the end of the season. The different injuries sustained throughout the year were logged for each player. This study shows that there is a difference between the intensity of training in different groups of players. The midfielders trained at the highest intensity and, in this group of professional football players, defenders sustained the most injuries GPS technology allows monitoring of player intensity during training. The data obtained will guide training and fitness coaches model training for the individual group of players. This will prepare players for official matches and eventually may help predict and prevent injuries

Background and purpose. The prevalence of back pain has remained relatively constant in the population in spite of previous interventions. Persons with sub-acute back pain are assumed to benefit from extended multidisciplinary, interdisciplinary or transdiciplinary and multisectorial, intersectorial or trans-sectorial interventions as an alternative to traditional mono-professional interventions. The purpose of this health technology assessment (HTA) was to document the possible effect of such interventions in patients suffering from back pain of 4-12 weeks duration. Methods and results. A systematic literature review is the overall basis for this HTA and the analysis of the interventions in relation to technology, patients, organization, and economics. HTA reports, systematic reviews, and recent primary studies were included. Further, primary data from Danish institutions (public and private) with experience in working with this technology were collected. There is moderate evidence that early multidiciplnary, interdisciplinary and transdiciplinary interventions are more effective than monodiciplinary interventions or no interventions in primary care. The effects are mainly seen in relation to reduced sick leave at or beyond 12-months follow-up and not in relation to reduced pain or improved function. The interventions appear to be cost-effective. Danish back centers mainly use sequential and/or parallel collaborative models. Conclusions. Extended multidisciplinary, interdisciplinary or transdiciplinary and multisectorial, intersectorial or trans-sectorial interventions delivered to patients with back pain of 4-12 weeks duration reduce sick-leave and appear to be cost-effective. The optimal content of such interventions cannot be determined but elements of cognitive behavioral therapy combined with graded exercise is used most frequently

Purpose Of The Study: To compare the Coblation technology Vs standard diathermy regarding surgical time & cost in arthroscopic subacromial decompression. Methods & Results: This prospective randomized comparative study between Coblation technology Vs standard monopolar diathermy in ASD. 40 patients with chronic impingement syndrome prospectively randomized 20 patients in each group. Procedure time & cost per case were accurately calculated. Results show that the Coblation group had an average 8 minutes shorter procedure time per case P value: 0.0001. The cost saving as a result was about £64 per case P value: 0.01. Conclusion: Use of Coblation technology for soft tissue debridement & resection in ASD reduces procedure time by 38% and the cost by an average of 18% per case (£64) compared with the use of a shaver and diathermy probe

Computer-assisted techniques in total knee replacement (TKR) have been introduced to improve bone cuts execution and relevant prosthesis components positioning. Although these have resulted in good surgical outcomes when compared to the conventional TKR technique, the surgical time increase and the use of additional invasive devices remain still critical. In order to cope with these issues, a new technology in TKR has been introduced also for positioning prosthetic components according to the natural lower-limb alignment. This technique is based on custom-fit cutting block derived from patient-specific lower-limb scan acquisition. The purpose of this study is to assess the accuracy of the custom-fit technology by means of a knee surgical navigation system, here used only as measurement system, and post-operative radiographic evaluations. Particularly, the performances of two different custom-fit cutting blocks realized from as many scan acquisitions have been here reported. Thirty patients affected by primary knee osteoarthritis were enrolled in this study. Fifteen patients were implanted with GMK® (Medacta-International, Castel San Pietro, CH) and as many patients with Journey® (Smith&Nephew, London, UK). Both TKR designs were implanted by using custom-fit blocks for bone cut executions provided by the same TKR manufacturers according to a pre-operative web planning approved by the surgeon. Particularly, the cutting block for the former design was built from CT scan acquisition of the hip, knee and ankle, whereas that for the latter design from MRI scans acquisition of the knee and X-ray lower-limb overview. A knee surgical navigation system (Stryker®-Leibinger, Freiburg, Germany) was used for recording intra-operative alignment of bone cuts as performed by means of the custom-fit cutting blocks and relevant component positioning. Prosthetic components alignments were also assessed post-operatively on X-ray images according to a shape-matching technique. The accuracy of the custom-fit blocks was evaluated through the comparison between pre-operative planning, and intra/post-operative data. Discrepancies above 3° and millimeters were considered as outliers. Within the patient cohort, nine cases were fully analyzed at the moment and here reported. Over them and except for one case, the discrepancy between pre-operative planned femoral/tibial resection level on the frontal plane and the corresponding measured intra-operatively was within 3 mm, being 5 mm in the worse case. Two outliers were observed for the corresponding femoral/tibial cut rotational alignment. Particularly, in one patient, the discrepancy in femoral cut alignment was of 8° in flexion and 6° in external rotation; in another patient this was of 4° in extension and 4° in external rotation in the femoral and tibial cut alignment, respectively. Post-operative radiographs evaluations for the final prosthetic components revealed that femoral/tibial alignment were within 3° in all cases, except for those patients that were already outliers. These preliminary results reveal the efficacy of the custom-fit cutting block for TKR. These were generally fitted properly and final prosthetic components were accurately placed, although some discrepancies were observed. This new technology seems to be a valid alternative to conventional and computer-assisted techniques. More consistent conclusions can be deduced after final evaluation of all patients

Flock technology is well known from textile industry. Short fibres are applied vertically on a substrate, coated with a flocking adhesive. Until now this technology has not been used in the field of biomaterials although it offers the possibility to create anisotrophic matrices with a high compressive strength despite of high porosity. Matrices presently used in matrix assisted autologous chondrocyte implantation do not show any orientation of the embedded chondrocytes. However column orientation and anisotropic direction of embedded cells and collagen fibers are thought to be necessary for proper cartilage matrix biomechanics. Combination of matrices as a guiding structure and chondrogenically differentiated mesenchymal stem cells (MSC) could offer new possibilities in the treatment of cartilage defects. Our aim was to evaluate whether anisotropic scaffolds are capable to support a cellular cartilaginous phenotype in vitro. Electrostatically flocked matrices consisted of a collagen substrate, gelatine as adhesive and polyamide flock fibres. Chondrogenic cells and MSC were embedded in the scaffolds. Adherence, vitality and proliferation was assessed using confocal laser-scan microscopy (cLSM). Chondrogenic induction was performed in the presence of TGF-beta 3. Accumulation of proteoglycans was quantified by alcian-blue stain and collagen type II synthesis after extraction of the newly synthesized matrix. cLSM showed proliferation of embedded MSC as evidenced by DAPI/Phalloidin stain. Vitality of embedded cells remained high over time. Articular chondrocytes and nucleus pulposus cells synthesized proteoglycans and collagen type II in the scaffolds. Also MSC embedded in the flock scaffolds differentiated and increased their chondrogenic phenotype over time. Using cLSM and biochemical analyses we demonstrated that cells adhered and proliferated well in the new scaffolds. Furthermore we showed that the scaffolds are capable to support induction and maintenance of the chondrogenic phenotype. We conclude that flocking technology is suitable for fabrication of scaffolds for cell cultivation and cartilage tissue engineering

Good clinical outcomes of Total Knee Arthroplasty (TKA) demand the ability to plan a surgery precisely and measure the outcome accurately. In comparison with plain radiograph, CT-based 3D planning offers several advantages. More specifically, CT has the benefits of avoiding errors resulting from magnification and inaccurate patient positioning. Additional benefits include the assessment in the axial plane and the replacement of 2D projections with 3D data. The concern on 3D CT-based planning, however, lies in the increase of radiation dosage to the patients. An alternative is to reconstruct a patient-specific 3D model of the complete lower extremity from 2D X-ray radiographs. This study presents a clinical validation of a novel technology called “3XPlan” which allows for 3D prosthesis planning using 2D X-ray radiographs. After a local institution review board (IRB) approval, 3XPlan was evaluated on 24 patients TKA. Pre-operatively, all the patients underwent a CT scan according to a standard protocol. Image acquisition consisted of three separate short spiral axial scans: 1) ipsilateral hip, 2) affected knee and 3) ipsilateral ankle. All the CT images were segmented to extract 3D surface models of both femur and tibia, which were regarded as the ground truth. Additionally, 2 X-ray images were acquired for each affected leg and were used in 3XPlan to derive patient-specific models of the leg. For 3D models derived from both modalities (CT vs. X-ray), five most relevant anatomical parameters for planning TKA were measured and compared with each other. Except for tibial torsion, the average differences for all other anatomical parameters are smaller than or close to 3 degrees

Aim. To introduce and promote a new technic and a new component using the 3D technology in the extreme acetabular revisions. Method. Since 2012, 13 patients, nine women and four men, were treated, 12 for a chronic complex PJI and one for an aseptic loosening. The average age was 75 years old (60 -90 years), the average follow-up 18,6 months (7–36 months). The revisions were bipolar in 12 cases and unipolar in one case for the oldest patient. For the septic cases, we performed 7 one stage procedure and 5 two stages. The femoral components were in 7 cases a modular stem, in 5 cases a massive component and a total femur. All these massive components were combined with a cemented double cup. The bone loss was evaluated with the AAOS, the Praposky and the Saleh classifications. A preoperative and postoperative Oxford score was used. Results. The bone loss are major; 9 stades III, 4 IV for the AAOS classification, 7 III A, 6 III B for the Praposky and 3 III, 6 IV, 4 V for the Saleh classification. The classifications weren't change by the component removal. 10 components were implanted without using cement. For the three cemented implants, the bone loss interested the columns and the roof. An acetabular disruption isn't a contrindication of an uncemented option. We report one early failure, in relation with no surgical postoperative complications. A good preoperative anchorage had never failed in the follow-up. The preoperative Oxford score was on average 8,9 (4–15) and the postoperative 33,6 (16–44). We report one early failure f a two stage procedure. Two patients underwent a recovery for partial change with no custom made implant involvement. In doing so, we have found that these cement less implants were well integrated and stable two months after the implantation. The most significant events are skin complications always after an extensive debridement, treated systematically by an iterative debridement. None of these complications appear to be related to the use of these implants. Conclusions. It's the first series which reports the use of the powder technology for a custom made component. In our series, it interests specific situations; elderly patients failing conventional medico-surgical strategies in complex functional and PJI. First results are really promising. This technology simplifies the complex acetabular reconstructions. It's a key point for the immediate postoperative functional management and to limit complications

Introduction. The purpose of this study was to use patient generated digital surveillance PROM's to track outcomes of TKA, Medial PKA, Lateral PKA. Methods. From Aug 2018 until June 2019 we performed 873 knee arthroplasties. Of these, 41 were fixed bearing lateral partial knee replacements (5%), 309 medial partial knee replacements (35%), and 523 total knee replacements (60%). The average age was 65 years old and 59% were female. KOOS-Jr scores were recorded preoperatively, and 6, 12 months postoperatively using digital surveillance technology with a greater than 90% response rate. Results. Baseline, 6 month, and 12 month KOOS-JR scores for TKR (54, 76, 79) were not different than baseline, 6 month, and 12 month KOOS-JR scores for medial PKA (56, 78, 82) [p values of 0.23, 0.32, 0.20 respectively]. Baseline and 6 month KOOS-JR scores for TKR were not different than baseline and 6 month KOOS-JR scores for lateral PKA (55, 77) [p values of 0.35 and 0.50 respectively). Where as, the 12 month KOOS-JR scores for TKR (79) were significantly less than 12 month KOOS-JR scores for lateral PKA (84)[p value of 0.04]. Baseline, 6 month, and 12 month KOOS-JR scores for medial PKR were not different than lateral PKR (55, 77, 84) [p values of 0.49, 0.39, 0.20]. Conclusions. Prospective digital surveillance of PROM following knee arthroplasty has proven to be a cost-effective strategy. Short term improvements in PROM's following TKA and medial PKA were not different. Lateral PKA demonstrated statistically significant higher 1 year PROM but unlikely clinically significant. Longer-term follow-up is needed for determination of implant and unreplaced compartment survivorship. For figures, tables, or references, please contact authors directly

Abstract

Biomedical imaging is essential in the diagnosis of musculoskeletal pathologies and postoperative evaluations. In this context, Cone-Beam technology-based Computed Tomography (CBCT) can make important contributions in orthopaedics. CBCT relies on divergent cone X-rays on the whole field of view and a rotating source-detector element to generate three-dimensional (3D) volumes. For the lower limb, they can allow acquisitions under real loading conditions, taking the name Weight-Bearing CBCT (WB-CBCT). Assessments at the foot, ankle, knee, and at the upper limb, can benefit from it in situations where loading is critical to understanding the interactions between anatomical structures. The present study reports 4 recent applications using WB-CBCT in an orthopaedic centre.

Patient scans by WB-CBCT were collected for examinations of the lower limb in monopodal standing position. An initial volumetric reconstruction is obtained, and the DICOM file is segmented to obtain 3D bone models. A reference frame is then established on each bone model by virtual landmark palpation or principal component analysis. Based on the variance of the model point cloud, this analysis automatically calculates longitudinal, vertical and mid-lateral axes. Using the defined references, absolute or relative orientations of the bones can be calculated in 3D.

In 19 diabetic patients, 3D reconstructed bone models of the foot under load were combined with plantar pressure measurement. Significant correlations were found between bone orientations, heights above the ground, and pressure values, revealing anatomic areas potentially prone to ulceration. In 4 patients enrolled for total ankle arthroplasty, preoperative 3D reconstructions were used for prosthetic design customization, allowing prosthesis-bone mismatch to be minimized. 20 knees with femoral ligament reconstruction were acquired with WB-CBCT and standard CT (in unloading). Bone reconstructions were used to assess congruency angle and patellar tilt and TT-TG. The values obtained show differences between loading and unloading, questioning what has been observed so far. Twenty flat feet were scanned before and after Grice surgery. WB-CBCT allowed characterization of the deformity and bone realignment after surgery, demonstrating the complexity and multi-planarity of the pathology.

These applications show how a more complete and realistic 3D geometric characterization of the of lower limb bones is now possible in loading using WB-CBCT. This allows for more accurate diagnoses, surgical planning, and postoperative evaluations, even by automatisms. Other applications are in progress.

Introduction. A careful evaluation of new technologies such as robotic-arm assisted total knee arthroplasty (RATKA) is important to understand the reduction in variability among users. While there is data reviewing the use of RATKA, the data is typically presented for experienced TKA surgeons. Therefore, the purpose of this cadaveric study was to compare the variability for several surgical factors between RATKA and manual TKA (MTKA) for surgeons undergoing orthopaedic fellowship training. Methods. Two operating surgeons undergoing orthopaedic fellowship training, each prepared six cadaveric legs for cruciate retaining TKA, with MTKA on one side (3 knees) and RATKA on the other (3 knees). These surgeons were instructed to execute a full RATKA or MTKA procedure through trialing and achieve a balanced knee. The number of recuts and final poly thickness was intra-operatively recorded. After completion of bone cuts, the operating surgeons were asked if they would perform a cementless knee based on their perception of final bone cut quality as well as rank the amount of mental effort exerted for required surgical tasks. Two additional fellowship trained orthopaedic assessment surgeons, blinded to the method of preparation, each post-operatively graded the resultant bone cuts of the tibia and femur according to the perceived percentage of cut planarity (grade 1, <25%; grade 2, 25–50%; grade 3, 51–75%; and grade 4, >76%). The grade for medial and lateral tibial bone cuts was averaged and a Wilcoxon signed rank test was used for statistical comparisons. Assessment surgeons also determined whether the knee was balanced in flexion and extension. A balanced knee was defined as relatively equal medial and lateral gaps under relatively equal applied load. Results. Operating surgeons used 9mm polys in all 6 RATKA specimens, and 3/6 MTKA specimens. Operating surgeons said they would do cementless in 4/6 RATKA specimens, and 1/6 MTKA specimen. In MTKA specimens, 5/6 cases had a recut on the tibia or femur to obtain knee balance. With RATKA, 1/6 cases had a recut on the tibia. With RATKA, operating surgeons performed a pre-resection balancing workflow, and made plan adjustments prior to resection. The operating surgeons reported reduced mental effort when performing bone measurements, tibial bone cutting, knee balancing, trialing, and post-resection adjustments with RATKA compared to MTKA. Mental effort was equivalent during femoral bone cutting between the two procedures and increased for RATKA during initial exposure and retractor setup. Assessment surgeons considered all 6 RATKA and 2/6 MTKA specimens to be balanced. Assessment surgeons assigned RATKA specimens a higher grade for perceived planarity (3.86 vs. 3.48, p=0.03) than MTKA specimens. DISCUSSION. In this cadaveric study, RATKA resulted in a higher usage of minimum poly thickness, greater tendency to want to use cementless components, higher number of balanced knees, higher perceived planarity, lower number of recuts, and reduced mental effort than MTKA cases. RATKA may give users more confidence in performing cementless TKA, especially for novice surgeons. Robotic-arm assisted TKA may allow for reduced surgical variability, which may improve patient outcomes, and should be investigated in a clinical setting

Objective: To point out the strict rules of surgical technique required for the success of newly applied advanced technology. Materials: 73 hips in 70 patients, aged 23 to 71 years old, underwent total hip arthroplasty using ceramic bearing surfaces implants. 62 were a primary procedure, and 11 were revision surgery. Results: One complication of fracture of posterior ace-tabular wall was registered in a patient with ankylosing spondylitis, four early dislocations that were reduced closed, and one case of late postoperative death in a cardiac high-risk patient. No other complications were recorded since the first operation in May 1999. All patients had remarkable pain relief, improved range of motion and improved function. Discussion: The tribological properties of the ceramic articulating surfaces favors them as the preferred technology for future orthopaedic implants. By reducing wear to a minimum the choice of ceramics seems to be justified. The main concern is fragility versus toughness. We have formulated ten rules of proper surgical technique concerning: accurate fit of the components, accurate orientation of the components, stability of the joints, adequate tissue tension, caring for debris and prevention of metal transfer due to ceramic-metal touch. Conclusions: While our clinical experience is still short term, it appears that applying a rigorous and uncompromising surgical technique with ceramic bearing surfaces is essential for the clinical success of this potent bio-material. Based on our experience, our recommendations are that:. Ceramic bearing surfaces T.H.A.-s should be performed in specialized centers. The use of 32 mm. heads should be considered in order to avoid dislocations. With 28 mm. heads, full profile cups should be considered. Conservative physical therapy and range of motion exercises for 6–12 weeks

Healthcare associated infections (HAI) pose a major threat to patients admitted to hospitals, and infection rates following orthopaedic arthroplasty surgery are as high as 4%, while the infection rates are even higher after revision surgery. 405 nm High-Intensity Narrow Spectrum (HINS) light has been proven to reduce environmental contamination in hospital isolation rooms, and there is potential to develop this technology for application in orthopaedic surgery. Cultured rat osteoblasts were exposed to 405 nm light to investigate if bactericidal doses of light could be used safely in the presence of mammalian cells. Cell viability was measured by MTT reduction and microscopy techniques, function by alkaline phosphatase activity, and proliferation by the BrdU assay. Exposures of up to a dose of 36 J/cm. 2. had no significant effect on osteoblast cell viability, whilst exposure of a variety of clinically relevant bacteria, to 36 J/cm. 2. resulted in up to 100% kill. Exposure to a higher dose of 54 J/cm. 2. significantly affected the osteoblast cell viability, indicating dose dependency. Work also demonstrated that 405 nm light exposure induces reactive oxygen species (ROS) production in both mammalian and bacterial cells, as shown by fluorescence generated from 6-carboxy-2′,7′-dichlorodihydrofluorescein diacetate dye. The mammalian cells were significantly protected from dying at 54 J/cm. 2. by catalase, which detoxifies H. 2. O. 2. Bacterial cells were significantly protected by sodium pyruvate (H. 2. O. 2. scavenger) and by a combination of free radical scavengers (sodium pyruvate, dimethyl thiourea (·OH scavenger), catalase) at 162 and 324 J/cm. 2. Thus the cytotoxic mechanism of 405 nm light in mammalian cells and bacteria is likely oxidative stress involving predominantly H. 2. O. 2. generation, with other ROS contributing to the damage. Additional work describing the potential for incorporation of this antimicrobial light within operating theatre lighting systems will also be discussed, and this, coupled with the cell viability and cytotoxicity results, suggests that 405 nm light could have great potential for continual patient safe decontamination during orthopaedic replacement surgeries and thereby reduce the incidence of infections

Introduction. Ideally, standardized wear testing protocols replicate the in vivo motions and forces of TKR patients. In a previous study with 30 TKR patients, two distinct in vivo gait patterns emerged, one characterized as having low anteroposterior (AP-L) motion and the other high anteroposterior (AP-H) motion. The aim of this study was to determine the effect of the two in vivo-determined gait patterns on total and backside insert wear in comparison with the ISO standard 14243-3. In order to differentiate and accurately quantify topside and backside wear, a novel technique was employed where different lanthanide tracers are incorporated into the polyethylene during manufacture. Materials and Methods. Components from the Zimmer NexGen CR Knee Replacement System were used. Europium (Eu) and Gadolinium (Gd)-stearates were mechanically mixed with GUR1050 UHMWPE resin to obtain two tracer-UHMWPE resins containing 49.1±1.5 ppm Eu and 68.8±1.6 ppm Gd, respectively. 12 grams of the Eu-doped resin was placed on the bottom, 10 grams of virgin GUR1050 resin was placed in the middle, and 10 grams of Gd-doped resin was placed on the top to mold NexGen CR tibial inserts. The backside was then machined to interlock with the tibial baseplate. The minimum insert thickness was 10 mm. All inserts were packaged in nitrogen and gamma sterilized. The wear test was conducted on a 4-station knee simulator in displacement-control mode. Simulator input was obtained from ISO 14243-3 and from gait of 30 NexGen TKR subjects, previously categorized into low (AP-L) and high (AP-H) anteroposterior motion groups. Per station, each insert was sequentially subjected to ISO, AP-L, AP-H motion for 2 Mc at 1 Hz. Subsequently, the ISO profile was repeated. Tibial inserts were weighed and lubricant samples were taken after every 0.5 Mc interval. Knowing the Eu and Gd concentrations from ICP-MS analysis, and normalizing those to the concentrations in the polyethylene inserts, the localized (Eu – backside; Gd – topside) wear was calculated. Wear particle analysis was conducted following established protocols. Results. For all tested liners (n=4 + soak) during the three tested motion profiles, the chemically calculated wear correlated closely with the gravimetrically determined wear (R. 2. »0.8), with slopes not different from 1. Both in vivo motion groups displayed higher wear rates than the ISO group following the order of the AP motion amplitudes (Figure). Backside wear for ISO constituted 2.76% ± 0.90% (mean ± SE) of the total wear, increasing significantly to 15.8 ± 3.2% for AP-L and further increasing to 19.3 ± 0.95% for AP-H (p<.001). The mean wear particle sizes were under 200 nm for all three motion patterns, being largest for the AP-H gait protocol (Table). Discussion. Both in vivo motion groups displayed higher wear rates than the group tested per ISO standard 14243-3. Interestingly backside wear was affected the most and increased 4.5 to 6-fold over ISO. Testing for the proportion of backside wear across various activities of daily living may therefore be an important consideration in evaluating knee prostheses wear and could be facilitated by this new tracer technology. For any figures or tables, please contact the authors directly

32 students of surgical technology were instructed in hip resurfacing, and shown detailed plans of the desired operative outcome for the 3 cam type hips. They then used conventional instruments, image-free navigation (brainlab) and image based navigation(Acrobot). Only image based navigation performed well enough at navigating these difficult cam type hips with novice surgeons. Conventional instruments were not sufficient, with a tendency for the novice to put the hip in varus and translated low on the femoral neck. Image free navigation was more accurate than conventional instruments, avoiding the serious complication of notching but the range of error was 18mm and 10¡. Image based navigation appears to be fit for purpose in delivering both the accuracy and the precision needed by the novice surgeon in the skills laboratory who needs timely feedback so his clinical experience may start substantially further along the learning curve of this or any other technically demanding operation

The osteoconductivity is the most desirable characteristic to achieve early fixation of the cementless-type artificial joints with bone. Apatite deposition on the surface of materials can induce the osteoconductivity in bony defect. In previous studies, various surface treatments have been proposed to provide titanium-based artificial joints with the osteoconductivity. The most popular surface treatment for commercial artificial joints is plasma-spray coating with apatite. Although the technique has been widely used for commercial artificial joints in the world, it remains some disadvantages attributed to high temperature during the process, such as fracture at the interface between metal and apatite, changes in the composition, crystallinity and structure of plasma-sprayed apatite. The chemical surface treatment with NaOH and H2O2 solution to provide spontaneous apatite-forming ability in the body could overcome the problems of plasma-spray process, since the treatments could be expected to not only continually express the apatite-forming ability in the body but also deposit the bone-like apatite having the similar crystal structure, crystallinity and composition of bone apatite. Therefore, surface treatments provided the spontaneous apatite-forming ability would be effective for titanium-based artificial joints with osteoconductivity. Recently, our research group developed the extremely simple technique for providing the spontaneous apatite-forming ability to titanium by both spatial design and thermal oxidation, denoted as “GRAPE technology”. Pure titanium with machined micro-groove of less than 800 μm in depth and 1000 μm in width and thermally oxidized at 400°C in air induced apatite deposition in the internal space of micro-grooves during exposure to simulated body fluid. In this study, the application possibility of GRAPE technology was examined by using Ti-6Al-4V and Ti-15Zr-4Ta-4Nb. Apatite formed on the thermally oxidized Ti-15Zr-4Ta-4Nb at 500 and 600°C with micro-groove 500 μm wide and depth in the simulated body fluid for 7 days. In contrast, no apatite formation was observed on the thermally oxidized Ti-6Al-4V at 400, 500 and 600°C with micro-groove 500 μm wide and depth in the simulated body fluid for 7 days. Okazaki et al. reported that Ti-15Zr-4Ta-4Nb shows higher corrosion resistance, mechanical properties and cytocompatibility than Ti-6Al-4V. Hence, it is expected that the Ti-15Zr-4Ta-4Nb with GRAPE technology could be innovative cement-less artificial joints to achieve early fixation through its osteoconductivity and excellent performances

Computer-assisted technology has provided surgeons with intra-operative quantitative measurement tools that have led to the development of soft-tissue balancing algorithms based on surgeon-applied varus-valgus stress. Unfortunately these forces tend not to be standardised and the resultant algorithms may at best be surgeon-specific. Furthermore, these techniques are only available intra-operatively and rely on the rigid fixation of trackers to bone. The aim of this study was to develop a non-invasive computer-assisted measurement technique and assess the variation in collateral knee laxity measurements between different clinicians. An image-free navigation system was adapted for non-invasive use by developing external mountings for active infrared trackers. A leg model with rigid tracker mountings was designed and manufactured for comparison. Multiple kinematic registrations of alignment were made for both the model and the right leg of a volunteer to quantify the soft tissue artefacts. Repeatability of the system was assessed by performing two registration processes on eight volunteers. Collateral knee laxity was assessed on a single volunteer by 16 participants of varying experience each applying a maximum varus and valgus knee stress. Two surgeons performed repeated examinations to assess intra-observer variation. For repeated registrations of alignment, the SD of the non-invasive mounting (0.8°) was only a third higher than the leg model (0.6°) and the actual range was only 1° larger. The repeated alignment measurements on the volunteers showed a high level of agreement with an intraclass correlation coefficient of 0.93. Varus-valgus stress values showed poor inter-observer variation with a wide range of angles for both varus (1° to 7°) and valgus stress (0.5° to 5°). A Mann-Whitney test between the two sets of repeated tests showed that both varus stress and overall laxity were significantly different (p< 0.0001) but that valgus stress was marginal (p=0.052). Intra-observer measurements overall appeared more consistent. Soft tissue artefacts did not significantly reduce the repeatability of the assessment of coronal knee alignment using a navigation system and this provided a non-invasive technique for assessing coronal knee laxity. The perception of an ‘end-point’ varied significantly between different clinicians and although there may be a role for surgeon-specific algorithms, to use this quantitative data more widely there is a need to standardise the forces and moments applied

Metal-on-metal hip resurfacing arthroplasty (MoMHRA) has been a popular alternative treatment for young patients with hip osteoarthritis. Despite its advantages over total hip arthroplasty, the use of MoMHRA remains controversial. Achieving the correct positioning of the prosthetic is a concern due to the difficulty and novelty of this procedure. Furthermore, it has been reported that post-operative management using 2D radiographs contains high degrees of variance leading to poor detection of prosthetic malpositioning. In order to compensate for the lack of available technology, current literature has suggested the use of blood metal ion levels as indirect predictors of prosthetic malpositioning due to the abnormal release of metal ions, particularly Chromium and Cobalt, as a result of increase wear and tear. The purpose of this study was to determine whether 2D/3D registration technology can report prosthetic orientation in vivo and, to establish whether 3D technology can accurately deduce prosthetic wear by correlating prosthetic angles with metal ion counts. To begin this study, post-operative x-rays (n=72) were used as the two-dimensional media to measure acetabular orientation. Only the acetabular component was examined in this study and acetabular orientation was defined as the function of inclination and version angles. Virtual three-dimensional models of the native, pre-operative pelvises and the acetabular implant were generated and were manually superimposed over the post-operative x-ray images according to anatomical landmarks. A manual 2D/3D registration program was specifically designed for this task. Inclination and version angles of the 2D/3D registered product were measured. Post-operative CT models, which offer the most accurate depiction of the prosthetic in vivo, were generated for validation. Contrary to the study's hypotheses and current literature, no significant difference was observed between 2D vs. 2D/3D vs. CT data, suggesting that 2D and 2D/3D measurements were similar to the results of the gold standard CT model (although 2D/3D measurements were more precise compared to 2D media). Furthermore, statistical analyses revealed no significant correlation in either 2D or 2D/3D compared to metal ion levels, although a stronger trend was demonstrated using 2D/3D measurements. These results are suggestive that 2D/3D registered measurements are equivocal to those using the conventional 2D x-ray and, manual 2D/3D registered measurements do not demonstrate greater efficacy in predicting prosthetic wear. Moreover, the data from this study also revealed insignificant correlations between the angles of acetabular orientation and metal ion release. Combined angles within and beyond the acceptable ranges for inclination (30°–50°) and version (5°–20°) angles did not produce significant trends with metal ion release. These results lead to the paradoxical conclusion that acetabular orientation does not influence prosthetic wear. The findings of this study are inconsistent with the reports in current literature and further investigation is required

Introduction. As population grows older, and patients receive primary joint replacements at younger age, more and more patients receive a total hip prosthesis nowadays. Ten-year failure rates of revision hip replacements are estimated at 25.6%. The acetabular component is involved in over 58% of those failures. From the second revision on, the pelvic bone stock is significantly reduced and any standard device proves inadequate in the long term [Villanueva et al. 2008]. To deal with these challenges, a custom approach could prove valuable [Deboer et al. 2007]. Materials and methods. A new and innovative CT-based methodology allows creating a biomechanically justified and defect-filling personalized implant for acetabular revision surgery [Figure 1]. Bone defects are filled with patient-specific porous structures, while thin porous layers at the implant-bone interface facilitate long-term fixation. Pre-operative planning of screw positions and lengths according to patient-specific bone quality allow for optimal fixation and accurate transfer to surgery using jigs. Implant cup orientation is anatomically analyzed for required inclination and anteversion angles. The implant is patient-specifically analyzed for mechanical integrity and interaction with the bone based upon fully individualized muscle modeling and finite element simulation. Results. Ten clinical severe pelvic bone defects, classified Parosky IIIb, have benefited from this methodology so far. Implant outline, thickness, fixation and cup orientation was adapted to the anatomical situation. Stress shielding of the bone was eliminated by taking into account personalized muscle anatomy, bone quality and patient weight while evaluating the design performance. All implants were applied smoothly intra-operatively because of personalized case documentation provided and jig technology for accurate pre-drilling of screw holes. Postoperative imaging showed excellent results. Short term follow-up indicates good outcome for the patients treated, restoring mobility and functionality, and showing solid anchorage to the bone. Conclusion. Complex acetabular bone defects can be treated adequately and efficiently, using a personalized solution which addresses both patient's and surgeon's needs

Cost is a factor in the choice of prosthetic components in joint replacement. For a given performance, the least expensive components are the most cost-effective. When evaluating a new prosthesis with an unknown outcome, the use of an economic model allows estimation of potential cost-effectiveness. We used published data for the survival of cemented total hip replacements from Sweden, and cost and demographic information from New South Wales, Australia, in such a model. In young active total hip recipients a new prosthetic design which offered a 90% improvement in survivorship over 15 years and a 15% reduction in the cost of revision surgery, could be sold at a price of 2 to 2.5 times that of conventional cemented components such as the Charnley Low Friction Arthroplasty and still be cost-effective. Using more likely estimates of the improved performance of new technology, however, the upper limit of cost-effectiveness is an increase of 1.5 to 1. Only a very small increase in the cost of a prosthesis could ever be justified for older patients of either sex. Most of the potential benefits of a better level of survivorship appear towards the end of the 15-year period. The results of modelling may be incorporated in clinical trial design. Given the known performance of some well-established and relatively inexpensive designs of prostheses, very large randomised studies would be required to prove an improvement in performance

Objective: Kinematic computer navigation technology has already shown improved alignment results in knee arthroplasty over the past years. But still all items and results are not perfect. The updated Orthopilot 4.0 navigation software is more sophisticated and gives the ability of additional navigation of soft tissue balancing. Together with the use of the new designed ultracongruent E-motion prosthesis, the Orthopilot 4.0 technology is very promising. Material and Methods: In this combined study equal groups (n=100) of patients were prospectively operated using E-motion prostheses navigated by Orthopilot 4.0 technology including ligament tension balancing (group G1), and Search prostheses navigated by the older Orthopilot 3.0 technique (G3). Conventionally operated patients served as control using LCS prostheses (G2, n=100), and former implanted Search prostheses (G4, n=50). The results of all groups were compared retrospectively. The results were radiologically evaluated by measuring pre-, and postoperative mechanical leg axes, femoral and tibial angles in both the coronal and the sagittal plane. In each cohort all surgeries were consecutively performed. Patients suffered from primary or secondary osteoarthritis. Results: Time of surgery did not differ significantly between group G1 and G2, but it was prolonged significantly for groups G3 and G4. In all patients of G1 a mechanical axis of 0 ± 5°, having 93% inside the excellent range of ± 3°, could be reached. Showing excellent ligament stability, full extension was possible much earlier than in the other groups. The mechanical axes in the control groups were more often different from optimum, with 63% inside an excellent range (G2), 76% (G3), and 57% (G4), respectively. For the femoral axis in the coronal plane, excellent results, i.e. ± 2% off optimum, were found in 95% (G1), 91% (G2), 97% (G3), and 77% (G4). The corresponding results for the femoral axes in the sagittal plane were 81% (G1), 79% (G2), 71% (G3), and 67% (G4). For the tibial axes in both planes the results were similar. All 5 axes in a perfect alignment at the same time were seen in 65% (G1), 40% (G2), 28% (G3), 22% (G4). In G1 femoral notching was inexistent. Discussion and Conclusion: During surgery, the new Orthopilot 4.0 navigation technique allows precise determination of collateral ligament tension in full extension and in flexion up to 90 degrees. This leads to perfect intraoperative planning of the tibial and femoral cut with respect to the required soft tissue release. In comparison to the control groups, this new technique leads to a significant improvement in postoperative results towards the desired optimal criteria, as there are: straight mechanical leg axes, little deviations from optimum for each single femoral and tibial axis, perfect collateral ligament balancing, and optimal range of movement

Orthopaedic surgeons and their patients continue to seek better functional outcomes after total knee replacement, but TKA designs claim characteristic kinematic performance that is rarely assessed in patients. The objectives of this investigation is to determine the in vivo kinematics in knees with Cruciate Retaining TKA using Patient Specific Technology during activities of daily living and to compare the findings with previous studies of kinematics of other CR TKA designs. Four knees were operated by Triathlon CR TKA using Patient Specific Technology and a fluoroscopic measurement technique has been used to provide detailed three-dimensional kinematic assessment of knee arthroplasty function during three motor tasks. 3D fluoroscopic analysis was performed at 4-month follow-up. The range of flexion was 90°(range 5°–95°) during chair-rising, 80°(range 0°–80°) during step up and 100° (range 0°–100°) during leg extension. The corresponding average external rotation of the femur on the tibial base-plate was 7.6° (range +4.3°; +11.9°), 9.5° (+4.0°; 13.5°) and 11.6° (+4.5°; +16.1°). The mean antero-posterior translations between femoral and tibial components during the three motor tasks were +4.7 (−3.7; +1.0), +6.4 (−3.8; +2.6) and +8,4 (−4.9; +3.5) mm on the medial compartment, and −2.5 (−7.1; −9.6), −3.6 (−6.1; −9.7), −2.6 (−7.7; −10.3) mm on the lateral compartment, respectively, with the medial condyle moving progressively anterior with flexion, and the medial condyle moving progressively posterior with flexion. We compared Triathlon CR PSI TKA results from this study with Genesis II CR TKA, with Duracon CR TKA, with Triathlon CR TKA and with the healthy knee kinematics. The results of this study showed no screw home mechanism. The internal rotation of the tibia with knee flexion is close to normal, better than Genesis II, Duracon and Triathlon CR TKA operated with standard surgery. The medial condyle is characterized by the same pattern of the other implants, with a paradoxical anterior translation of 5 mm. The lateral condyle shows a posterior rollback better than Triathlon CR operated with standard surgery. For the first time is demonstrated that the surgical technique can modify the tibio-femoral kinematics

Formal surgical skill assessment and critical path analysis are not widely used in orthopaedic surgical training due to the lack of technology for objective quantification, reliability, and the discrimination insensitivity of existing methods. Current surgical skill assessment methods also require additional instrumentation, cost and time. Such problems can be overcome by a novel method that records the motion of surgical instrumentation for the purposes of documentation, surgical-skill assessment, and safety analysis. This method uses an existing computer-aided-orthopedic-surgery (CAOS) navigation system and does not compromise its functions of real-time tracking, rendering, or simulation. The stored data allows realistic playback in 3D of the complete bone cutting/refining process. This concept and its sensitivity were previously tested and validated using a robotic arm as a reliable actuator for a surgical instrument moving in controlled paths. In this study, the system was used to evaluate the surgical skills of actual orthopaedic residents in a hospital/lab setting. Two chief orthopaedic surgery residents participated in the experiment. Each one cut all five distal cuts on four synthetic (right) femurs to accommodate the same femoral implant using NoMiss, an in-house built system for Navigated Freehand bone cutting. The motion of the surgical saw was recorded in real time by NoMiss during the whole procedure, but the real purpose of the experiment (and the recording) was not revealed to the residents until the end of all tests. Based on the data recorded by the navigation system, the following parameters were analyzed: cutting time, area-of-the-cut/time ratio, trajectory of the saw, errors in distance off the plane as well as errors in roll and pitch angles. While no significant difference among the two subjects was found in bone cutting time (mean 531s vs. 642s, p=0.099), subject 1 (S1) was faster than subject 2 (S2) in total time, which included cutting, reshaping of the bone, and implantation (mean 719s vs. 958 s, p=0.035). Area-of-the-cut/time ratio revealed higher (not significant) proficiency for S1 compared to S2 (mean 16 mm2/s vs. 13 mm2/s, p=0.084). Nevertheless considering individual cuts, there was significant difference in the posterior chamfer cut (mean 9 vs. 5 mm2/s, p=0.015). The analysis of the trajectory of the saw showed less conservative motion (and less consistency) for S1 than for S2 (average total length of trajectory 8.6m (sd=2.1m) vs. 8.1m (sd=0.4m), as well as larger paths in between cuts (average 39% vs. 33% of the total trajectory). The system/method was able to characterize different subjects without additional instrumentation, cost, time, awareness of or distraction to the user. Slightly better performance was detected for S1 compared to S2 presumably signifying superior skills. The main differences in this case appeared in the cutting of the chamfers, which might be considered the trickiest of the distal cuts in a navigated freehand cutting environment. A larger number of subjects with a wide level of expertise should be analyzed under similar conditions to establish quantitative acceptance limits (e.g. numerical determination for pass/fail criteria)

Introduction. The aim of this study is to investigate the accuracy and reliability of a Magnetic Resonance Imaging (MRI) based Patient Match Technology (PMT) system (VISIONAIRE, Smith & Nephew, Inc, Memphis, Tenn) by intraoperative use of VectorVision knee navigation software from BrainLAB (Redwood City, California, USA). Methods. Between February 2011 and May 2011, 15 patients with primary gonarthrosis were selected for unilateral Total Knee Arthroplasty (TKA). The first three patients were excluded from this study, as they were considered as a warm up to set up the procedure. Therefore 12 patients entered the study. Preoperatively all patient underwent a full-length weight-bearing radiograph in antero-posterior (AP) and a MRI according to the protocol suggested and approved by the manufacturer. All patients were operated with cemented posterior stabilised prosthesis cruciate ligament sacrificing (Journey BCS, Smith & Nephew, Inc, Memphis, Tennessee, USA) by the same surgeon using the VISIONAIRE patient matched cutting jigs. During surgery, once the guides were placed and fixed, the orientation was checked by the navigator. The following parameters were evaluated: size of the implant, alignment in coronal and sagittal plane. An unsatisfactory result was considered an error ≥ 2° in both plane for each component as a possible error of 4° could result in aggregate. Results. On the coronal plane the mean deviation of the tibial guide from the ideal alignment was 1.2°±1.5 (range 0–5°) with 2 cases > 2°, while in the sagittal plane was 3.8°±2.4 (range 0–7.5°) with 7 cases exceeding 2°. On the coronal plane the mean deviation of the femoral guide from the ideal alignment was 1.2°±0.6 with 1 case > 2°, while in the sagittal was 3.7°±2.0 with 3 cases exceeding 2°. The size of the custom cutting blocks were correct in all the patients. Conclusions. The results of this preliminary study documented a only fair accuracy of the method with a consistent risk of error of more than 2°, especially in the sagittal plane. We could speculate that the great error found in the tibial slope and femoral flexion is due to the lack of a preoperative radiological study of the overall lower limb in lateral view as only a MRI imaging with a lateral view extending 8 cm below joint line is acquired preoperatively. On the basis of this preliminary experience, the PMT system based only on data acquisition with AP radiograms and MRI cannot be defined as accurate. In cases using custom-made cutting jigs, we recommend performing an accurate control of the alignment before making the cuts in any step of the procedure

Preoperative planning for Total Hip Arthroplasty has been acknowledged as a vital step to facilitate a successful outcome. Templating ascertains the dimensions and positioning of the implants, minimizing both intraoperative and postoperative complications. The purpose of this study is to compare the accuracy of digital templating to acetate templating in the preoperative planning of Total Hip Arthroplasty.

Preoperative planning was performed on 40 consecutive patients (mean age = 70.5 years), undergoing Total Hip Arthroplasty. Digital templating was performed by the Hip fellow 1, using Orthoview software (Jacksonville, FL, USA) and recorded the sizes of the cup and stem for each of the 40 patients. Subsequently, the same 40 patients were templated by Hip fellow 2, with X-rays done with a lead marker of known size by the side of the femur, using, acetate templating method. Templating results were compared to the actual sizes of the implants used, as noted in operative notes. Templating scores for the acetabular cup were 40% (16/40) with digital templating and 50% (20/40) with acetate templating. The templating scores for stem were 28% (11/40) with digital templating and 90% (36/40) with acetate templating. The differences between templating and actual implant sizes were plotted in Bland–Altman plot. Acetate templating proved to be statistically, significantly more accurate than digital templating (p value= 0.0083).

Our results indicate that the traditional acetate method is solid and valid to use for preoperative planning. This method is accurate and offers a more affordable option for preoperative templating. Although the templated size is one, there is a tendency to increase cup size to use bigger heads, which is the recent National Joint Registries trend. We recommend that acetate templating should be used as the default option.

For decades, universities and research centers have been applying modeling and simulation (M&S) to problems involving health and medicine, coining the expression in silico clinical trials. However, its use is still limited to a restricted pool of specialists.

It is here proposed an easy-to-use cloud-based platform that aims to create a collaborative marketplace for M&S in orthopedics, where developers and model creators are able to capitalize on their work while protecting their intellectual property (IP), and researcher, surgeons and medical device companies can use M&S to accelerate time and to reduce costs of their research and development (R&D) processes.

Digital libraries on InSilicoTrials.com are built on collaborations among first-rate research center, model developers, software, and cloud providers (partners). Their access is provided to life science and healthcare companies, clinical centers, and research institutes (users), offering them with several solutions for the different steps of the orthopedics and medical devices R&D process. The platform is built using the Microsoft Azure cloud services, conforming to global standards of security and privacy for healthcare, ensuring that clinical data is properly managed, protected, and kept private. The environment protects the IP of partners against the downloading, copying, and changing of their M&S solutions; while providing a safe environment for users to seamlessly upload their own data, set up and run simulations, analyze results, and produce reports in conformity with regulatory requirements.

The proposed platform allows exploitation of M&S through a Software-as-a-Service delivery model. The pay-per-use pricing: 1. provide partners with a strong incentive to commercialize their high-quality M&S solutions; 2. enable users with limited budget, such as small companies, research centers and hospitals, to use advanced M&S solutions. Pricing of the M&S tools is based on specific aspects, such as particular features and computational power required, in agreement with the developing partner, and is distinct for different types of customers (i.e., academia or industry).

The first medical devices application hosted on InSilicoTrials.com is NuMRis (Numerical Magnetic Resonance Implant Safety), implemented in collaboration with the U.S. F.D.A. Center for Devices and Radiological Health, and ANSYS, Inc. The automatic tool allows the investigation of radiofrequency (RF)-induced heating of passive medical implants, such as orthopedic devices (e.g., rods and screws), pain management devices (e.g., leads), and cardiovascular devices (e.g., stents), following the ASTM F2182-19e2 Standard Test Method. NuMRis promotes the broader adoption of digital evidence in preclinical trials for RF safety analysis, supporting the device submission process and pre-market regulatory evaluation.

InSilicoTrials.com aims at defining a new collaborative framework in healthcare, engaging research centers to safely commercialize their IP, i.e., model templates, simulation tools and virtual patients, by helping clinicians and healthcare companies to significantly expedite the pre-clinical and clinical development phases, and to move across the regulatory approval and HTA processes.

Total knee arthoplasty (TKA) remains a standard treatment for advanced knee arthritis. The aim of the procedure is to restore function and relieve pain ideally for the rest of patient's life. Patient matched templating (PMT) or patient specific instrumentation (PSI) is a recent development for alignment of TKA components that uses disposable guides. The users of PSI claim it to be the optimum balance of new technology and conventional technique by reducing the complexity of conventional alignment and sizing tools. To assess the clinical and radiological outcome of Primary TKA done with PSI. More than 200 cases of TKA have been done in our unit using PSI and we analysed the radiographic outcome of these cases postoperatively. We also reviewed the clinical outcome of 103 patients with 1 year and 43 patients with 2 year follow-up. Data was collected prospectively: pre-operatively and at 1 year and 2 years post-operatively including Oxford knee score (OKS), WOMAC and American knee society score (AKS). Standard AP and lateral films were done pre-operatively and post-operatively. Mean age was 66 years. There were 56 female and 47 male patients. Mean post-operative angles on standard films were: Alpha = 95.6, Beta = 88.4, Saggittal femur = 3.4 and Saggittal tibia = 90.8. Of the 103 cases with 1 year follow-up, there was significant improvement in all clinical outcome scores. Mean OKS improved from 18 to 39 at 1 year and remained the same at 2 years, WOMAC improved from 40 to 18 in both 1 and 2 years post-op. AKS Total improved from 79 to 173 at 1 year and 170 at 2 years. Performing TKA using PSI is safe and provides good radiological alignment in the coronal and sagittal plane. Significant improvement in outcome scores were seen at one and two year follow up and reached levels that compared favourably with other reported series of TKA outcome from our unit

Bacterial infection related to orthopaedic implants is a significant complication today. One of the ways to reduce the incidence of implant-associated infections is assumed to give antibacterial activity to surface of implant itself. We focused attention on Ag, because it has a broad antibacterial spectrum, strong antimicrobial activity and low toxicity. In the previous works, sputtering, electrochemically deposition and sol-gel coating of Ag-containing hydroxyapatite (HA) have been reported. However, since practical technique of HA coating widely used for medical and dental implants has been the “thermal spraying” technique over the last two decades, we aimed at developing the novel thermal spraying technology for Ag-HA coating with antibacterial activity. In this study, physical and chemical properties, in vitro antibacterial activity, inhibition activity of bacterial attachment, HA-forming ability, cytotoxicity and release of Ag ions of the thermal-sprayed Ag-HA coating were evaluated. HA powder containing 3wt % of silver oxide (Ag2O) was sprayed on surface of titanium disks by the thermal spraying method using acetylene torch. SEM images showed a typical structure of the thermal-sprayed coating and the X-ray diffraction (XRD) pattern of the coating showed an amorphous structure. Ag residue in the coating was determined by the elementary analysis. The coating showed strong antibacterial activity and inhabitation activity of bacterial attachment to the methicillin-resistant Staphylococcus aureus (MRSA) in fetal bovine serum (FBS). On the other hand, the coating showed fast HA-forming ability in simulated body fluid (SBF) and no cytotoxicity related to Ag contained in the coating. Therefore, it is expected that the thermal-sprayed Ag-HA coating provides antibacterial and bone-bonding ability on the surface of the implant itself. In addition, though the HA coating is generally liable to adhere bacteria, the thermal-sprayed Ag-HA coating overcomes this problem. Pre-evaluation of release of Ag ions from the Ag-containing ceramic powders indicated that the releasing behavior of Ag ions in SBFs is dependent on the existing form of Ag in the Ag-containing material. It is assumed that most of Ag components in the Ag-HA coating are not retained as metallic Ag but as Ag2O in the amorphous layer. Time-course release tests of Ag ions from the coating in FBS showed a large release rate of Ag ions until 24 h after the immersion. It is expected that the Ag-HA coating could show strong antibacterial activity at the early post-operative stage. In the repeated release testing, the amount of released Ag ions was about 6500 ppb for the first release test, after which it gradually decreased. However, a significant release amount of Ag ions was observed even after the sixth repeat test. Therefore, it was assumed that the thermal-sprayed Ag-HA coating has a slow-release property of Ag ions in FBS

Aims

The aim of this study was to evaluate the accuracy of implant placement when using robotic assistance during total hip arthroplasty (THA).

Introduction

Virtual fracture clinics (VFCs) are being increasingly used to offer safe and efficient orthopaedic review without the requirement for face-to-face contact. With the onset of the COVID-19 pandemic, we sought to develop an online referral pathway that would allow us to provide definitive orthopaedic management plans and reduce face-to-face contact at the fracture clinics.

Aim: To assess the volume-outcome relationship of total hip replacement means of a Health Technology Assessment and to assess the effects of a minimum provider volume regulation on medical care in Germany. Methods: Electronic bibliographic databases, the reference lists of relevant articles and various health services research-related resources were searched and selected studies were assessed using defined quality criteria. Additionally, the implementation of these results and its consequences – excluding hospitals and/or surgeons that do not perform a defined number of operations a year from medical care – for the German Health System were calculated on routine data basis of the German Health insurance. Several different cut-off points (20 operations per year/50 operations per year) and the respective consequences on medical care were calculated. Results: 26 publications, that comprise in a narrower sense with the volume-outcome-relationship of total hip replacement, were assessed. The results in literature concerning defined outcome parameters are inconsistent, but a general correlation between high volume and low complication rate could be identified. In contrast a cut-off point, that is able to discriminate “good” from “bad” health care could not be deduced from the results in the literature. Methodological aspects of the performed studies concerning volume-outcome relationship are to be considered, too, i.e. study design, statistics, endpoint definition. In Germany 1264 hospitals performed 150.000 total hip replacements in 2005. Implementing a regulation based on minimum provider volumes of 20/50 total hip replacements/year would lead to an exclusion of 216 (17%)/483 (38%)hospitals respectively from medical care. This would result in a reallocation of 2214 (1.4%)/11.478 (7,4%) patients/ year respectively. Conclusion: Importance of HTA reports and expected consequences on health care will even increase in Germany especially regarding recent legal context. A correlation between high volume and low complication rate in total hip replacement could be identified by means of HTA. Keeping these results in mind and knowing that in consequence hospitals/surgeons that do not perform a defined number of operations a year will be excluded from medical care, the application of a minimum provider volume regulation in the German health care system must be performed very sensitve, because significant effects are to be expected

Introduction. Iatrogenic proximal femur hoop-stress fracture is a recognised complication of uncemented hip arthroplasty. It has a reported incidence of two to three percent and increases patient morbidity. We describe a novel technology that predicts fracture in real-time by less than one minute. Method. Four proximal femora from red deer (Cervus elaphus), similar size to human proximal femora, were prepared to accept an uncemented hip arthroplasty femoral rasp (Finsbury Orthopaedics) and then mounted in a loading machine. The femora were fresh-frozen, defrosted and kept at room temperature in 0.9% saline swabs. The rasp was forced into each femur in repeated loading cycles every 10 seconds, in steps of 100N increasing from 200N to over 2000N until fracture, in a manner to simulate surgery. One sensor was attached to the surface of the proximal femur and one to the femoral rasp. The sensor outputs were recorded, analysed and displayed on a PC using a software algorithm to show signal energy (joules) and amplitude (decibels). The proximal femur was coated with specular marking paint to permit real-time 3-D digital image correlation (DIC) analysis. DIC is an established tool in engineering fracture analysis and utilises two spatially orientated video cameras to measure surface strain and fracture. The femur was observed by the human eye and loaded in cycles until a fracture was seen. The moment of fracture was marked in the recording timeline. DIC was used to confirm fracture. Results. All femora fractured in the anterior proximal cortex. Signals from both sensors were identical in form and differed by less than five percent in strength during loading. Both signals demonstrated significant increases in energy and amplitude shortly prior to fracture. Early during loading cycles the femoral rasp subsided and became well-fixed within the femur; this was associated with signals of 60-70dB. During later loading cycles the rasp ceased to subside in the femur and was well-fixed in a press-fit; subsequent loading caused fracture and this was preceded by a greater number of stronger signals of over 90dB. The increase occurred 1 to 3 loading cycles prior to fracture, or less than 30 seconds. DIC was used to confirm the presence of a fracture visible to the human eye. At the time of the first significant increase in signal there was no crack visible to the eye or to DIC analysis and the femoral rasp did not subside further into the femur. Conclusions. During press-fitting of an uncemented femoral rasp in a deer femur a significant change in signal characteristics occurs shortly prior to a fracture being visible to the eye and detectable by DIC analysis. The almost identical signal output from both sensors suggests that one single sensor mounted on a femoral rasp will suffice, thereby removing the need to expose more of the proximal femur during surgery. This technology may be able to predict and therefore prevent femur fracture during uncemented hip arthroplasty. Further research is necessary in animal and human cadavers to explore and validate this research

Comminuted subtrochanteric fractures pose a clinical challenge; locking plate technology has been theorized to offer treatment advantages. A comminuted subtrochanteric femoral fracture model was created with a 2 cm gap below the lesser trochanter in fifteen matched pairs of human cadaveric femora confirmed to be non-osteoporotic. The femora were randomized to treatment with a trochanteric femoral nail (TFN), proximal femoral locking plate (PFLP), or 95° angled blade plate (ABP). Each was tested under incrementally increasing cyclic load up to 90,000 cycles to simulate progressive weight bearing during three months. The TFN was the strongest implant: it withstood significantly more cycles, failed at a significantly higher force, and withstood a significantly greater load than either plate (p< 0.001). Varus collapse was significantly lower in the TFN construct (p< 0.0001). Mode of failure differed among implants, with damage to the femoral head through implant cut-out in five of ten blade plate specimens and two of ten nail specimens, whereas no damage to the femoral head bone was observed in any of the PFLP specimens. The TFN was biomechanically stronger than the PFLP and this may have clinical relevance during the slow healing of subtrochanteric femoral fractures. The PFLP was biomechanically equivalent to the ABP but failure occurred without significant damage to the femoral head, suggesting that although biomechanically equivalent, the PFLP might have clinically relevant advantages in its mode of failure over the ABP

Introduction & Aims

Patient recovery after total knee arthroplasty remains highly variable. Despite the growing interest in and implementation of patient reported outcome measures (e.g. Knee Society Score, Oxford Knee Score), the recovery process of the individual patient is poorly monitored. Unfortunately, patient reported outcomes represent a complex interaction of multiple physiological and psychological aspects, they are also limited by the discrete time intervals at which they are administered. The use of wearable sensors presents a potential alternative by continuously monitoring a patient's physical activity. These sensors however present their own challenges. This paper deals with the interpretation of the high frequency time signals acquired when using accelerometer-based wearable sensors.

Peri-prosthetic joint infection (PJI) can be both a diagnostic and therapeutic challenge in shoulder arthroplasty, due to the indolent nature of the common infecting organisms. Proprionobacterium acnes (P. acnes) is the most common pathogen cultured in revision shoulder arthroplasty. It is a slow growing, anaerobic organism – requires longer incubation period (7–21 days). Coagulase-negative Staphylococcus species (CNSS) is also a common organism responsible for PJI.

Established diagnostic tests for hip and knee PJI are often negative in the shoulder despite post-operative growth of intra-operative cultures. Pre-operative synovial aspiration often low volume due to indolent pathogens and successful aspiration is often reported to be 50% or less with Dilisio et al, JBJS 2014: reporting 16.7% sensitivity, 100% specificity. Variable culture length for P. acnes culture protocols are reported from 7–28 days with most groups recommending 14 days.

From our research, we demonstrated time to culture growth was significantly shorter in probable true positive culture group (median, 5 vs. 9 days, p=0.002). Frozen section analysis may help intra-operative decision-making (one- vs. two-stage reimplantation) yet the reported sensitivity and specificity in shoulder arthroplasty is far less than in hip and knee arthroplasty. Synovial fluid biomarkers have been identified as part of the innate response to pathogens include pro-inflammatory cytokines and antimicrobial peptides. In a series of prospective studies of revision shoulder arthroplasty, synovial fluid analysis reported by Frangiamore et al, JBJS 2015: IL-6, Frangiamore et al, JSES 2015: α-defensin (Synovasure^TM), Frangiamore et al, AAOS 2015: Broader cytokine analysis it was demonstrated that these markers are much more predictive of infection than synovial fluid cultures, frozen section or serum markers.

Background: The mechanism of tissue removal and residual tissue damage for ultrasonic ablation instruments have not been adequately investigated. In particular, the relationship between applied force and amplitude of distal tip displacement as determinants of cutting effect and residual tissue damage has not been clearly defined. Recent clinical studies have highlighted the potentially deleterious thermal and mechanical effect of ultrasonic energy in residual tissue. Aims: To evaluate the role of ultrasonic tissue resection as an alternative to mechanical shaver and electrosurgical resection for orthopaedic applications. We aim to investigate factors influencing material removal rate (MRR), cutting rate (CR) and thermal damage for meniscus tissue resection using an experimental 20kHz ultrasonic ablation device. Methods: An experimental force controlled testing rig was constructed using a 20kHz ultrasonic probe suspended vertically from a load cell. Ex-vivo bovine meniscus samples were harvested from knee joints and cut into uniform 16mm discs. Effect of variation in force (2.5–4.5N) and amplitude of distal tip displacement (242–494μm peak-peak) settings on material removal rate (MRR) and cutting (CR) was analyzed. Time-discrete temperature elevation in the meniscus was measured by embedded thermocouples and infrared thermography. Statistical analysis was conducted using SPSS v.11.0 (SPSS Inc., Chicago, IL). The experiment was designed using a response surface quadratic model with both input variables treated as continuous, using Design-Expert v.7.1.3 (Stat-Ease Inc., Minneapolis, MN). Results: As either force or amplitude increases, there is a linear increase in MRR (Mean±SD: 0.9±0.4 to 11.2±4.9mg/s). A corresponding increase is observed in CR for increases in force and amplitude (Mean±SD: 0.08±0.04 to 0.73±0.18mm/s). Conversely, there is an inverse relationship between both force and amplitude, and temperature elevation, with higher force and amplitude settings resulting in less thermal damage. Maximum mean temperatures of 84.6±12.1°C and 52.3±10.9°C were recorded in residual tissue at 2mm and 4mm from the ultrasound probe-tissue interface respectively. Conclusions: Although high power low frequency ultrasound is capable of meniscal resection, key limitations of this technology are low MRR rate and thermal damage. The mechanism of removal is primarily thermal, with tissue temperatures reaching potentially dangerous levels. Control of user force and amplitude of tip displacement settings in ultrasonic instrument design can maintain temperature peaks below critical temperatures of thermal necrosis during operation

Lavage and preparation of the cancellous bony surface can facilitate adequate fixation of components in cemented total knee arthroplasty (TKA). Commonly used techniques for bone preparation such as pulse lavage, apart from adding to the cost, may cause local loss of loose cancellous bone and may even drive contaminants deeper into the tissue when used during TKA. We describe a simple, inexpensive and effective tool of using a sterilised toothbrush for preparing bone surface during cemented TKA. This must be followed by adequate pressurization of cement at the right time to achieve close interdigitation of cement with trabecular bone.

With the established success of the National Joint Registry and the emergence of a range of new national initiatives for the capture of electronic data in the National Health Service, orthopaedic surgery in the United Kingdom has found itself thrust to the forefront of an information revolution. In this review we consider the benefits and threats that this revolution poses, and how orthopaedic surgeons should marshal their resources to ensure that this is a force for good.

Capturing objective data of the postoperative changes in the mobility of patients is expected to generate a better understanding of the effect of postoperative treatment. Until recently, the collection of gait-related data was limited to controlled clinical environments. The emergence of accurate wearable accelerometers with sufficient runtime, however, enables the long-term measurement and extraction of mobility parameters, such as “real-world walking speed”. An interim analysis of 1967 hours of actibelt data (3D accelerometer, 100 Hz) from 5 patients (planned total 20) with a femur fracture and 5 patients (planned total 20) with a humerus fracture from a geriatric population at two different sites of the university hospital of the Ludwigs-Maximilian-University in Munich was performed. Mobility data was captured during several days of stationary treatment starting directly after surgery and during a short follow-up visit six weeks after the surgery. Preliminary results show an increase of the mean walking speed between the two visits independent of the type of fracture. Patients with a humerus fracture tended to walk faster than patients with a femur fracture during both visits. The data also reveals an unexpected low level of mobility during the stationary stay. Mobile accelerometry can be used to evaluate different postoperative mobilisation strategies and even provide near-time feedback in geriatric trauma patients.

One of the most common bacteria in orthopaedic prosthetic infections is Staphylococcus Aureus. Infection causes implant failure due to biofilm production. Biofilms are produced by bacteria once they have adhered to a surface.

Nanotopography has major effects on cell behaviour. Our research focuses on bacterial adhesion on nanofabricated materials. We hypothesise that surface nanotopography impacts the differential ability of staphylococci species to adhere via altered metabolomics and may reduce orthopaedic implant infection rate.

Bacteria were grown and growth conditions optimised. Polystyrene and titanium (Ti) nanosurfaces were studied. The polystyrene surfaces had different nanopit arrays, while the Ti surfaces expressed different nanowire structures. Adhesion analysis was performed using fluorescence imaging, quantitative PCR and bacterial percentage coverage calculations. Further substitution with ‘heavy’ labelled glucose into growth medium allowed for bacterial metabolomic analysis and identification of any up-regulated metabolites and pathways.

Our data demonstrates reduced bacterial adhesion on specific nanopit polystyrene arrays, while nanowired titanium showed increased bacterial adhesion following qPCR (P<0.05) and percentage coverage calculations (P<0.001). Further metabolomic analysis identified significantly increased intensity counts of specific metabolites (Pyruvate, Aspartate, Alanine and Carbamoyl aspartate).

Our study shows that by altering nanotopography, bacterial adhesion and therefore biofilm formation can be affected. Specific nanopatterned surfaces may reduce implant infection associated morbidity and mortality. The identification of metabolic pathways involved in adhesion may allow for a targeted approach to biofilm eradication in S. aureus. This is of significant benefit to both the patient and the surgeon, and may well extend far beyond the realms of orthopaedics.

Total knee arthroplasty has been shown to provide relief of pain and improved function; however studies have shown that younger active patients still note limitations in performing higher level activities such as dancing, golfing, skiing and gardening. Journey II BCS is designed to have physiological matching which more accurately reproduces the normal knee anatomy and kinematics. By providing more anatomic restoration of the articular geometry and substituting for both cruciate ligaments, Physiological Matching TKA has been shown, with in-vivo kinematic studies, to better reproduce the normal bending, rollback and rotational motions of knees.

Patient matched instruments are patient specific custom designed cutting blocks. These instruments utilise pre-operative MRI and full leg x-rays to design guides that will position the knee in the desired mechanical alignment. The purpose of these instruments is to increase efficiency and accuracy, and possibly reduce cost.

Efficiency occurs through the elimination of multiple steps compared to the standard operative technique. A single patient matched femoral guide is easily placed and can align the valgus angle with the mechanical axis, and determine the level of resection, rotation, size, and AP position of the implant. A single tibial instrument can determine tibial alignment, depth of resection, slope and rotation. Efficiency also results by eliminating the need for many standard instruments and trays. Implant size is determination pre-operatively so fewer implant trials are necessary.

In summary, this Physiological Matching TKA surgery combines Journey II BCS with patient specific instruments to optimise kinematics, fit and efficiency in order to improve outcomes and patient satisfaction.

Aims

We compared the accuracy, operating time and radiation exposure of the introduction of iliosacral screws using O-arm/Stealth Navigation and standard fluoroscopy.

The aim of this prospective multicentre study was to report the patient satisfaction after total knee replacement (TKR), undertaken with the aid of intra-operative sensors, and to compare these results with previous studies. A total of 135 patients undergoing TKR were included in the study. The soft-tissue balance of each TKR was quantified intra-operatively by the sensor, and 18 (13%) were found to be unbalanced. A total of 113 patients (96.7%) in the balanced group and 15 (82.1%) in the unbalanced group were satisfied or very satisfied one year post-operatively (p = 0.043).

A review of the literature identified no previous study with a mean level of satisfaction that was greater than the reported level of satisfaction of the balanced TKR group in this study. Ensuring soft-tissue balance by using intra-operative sensors during TKR may improve satisfaction.

Cite this article: Bone Joint J 2014;96-B:1333–8

INTRODUCTION

Wear induced osteolysis, material property degradation and oxidation remain a concern in cobalt chrome on polyethylene THR. ECIMA is a cold-irradiated, mechanically annealed, vitamin E blended HXLPE developed to maintain mechanical properties, minimise wear and improve long-term oxidation resistance. This study aimed to compare the in-vitro wear rate and mechanical properties of three different acetabular liners; UHMWPE, HXLPE and ECIMA.

INTRODUCTION

The purpose of TKA is to restore normal kinematics and functioning to diseased knees. The purpose of this study was to determine whether intraoperative kinematic data are correlated with minimum one-year outcomes following primary TKA.

Cementless biologic fixation surfaces on total joint replacement devices, such as those used in total hip and knee procedures, have evolved over the decades. Historically, various surfaces to allow bone ingrowth or ongrowth have been applied as a coating to a pre-formed solid metal substrate. As shown in Figure 1, from left to right, representative coating surfaces include sintered beads, diffusion-bonded fiber metal, and plasma sprayed titanium. In certain applications, tantalum porous metal (Fig 1, left) can be used without a solid metal substrate, but its most widespread usage is in a modular acetabular cup design with the porous metal diffusion-bonded to a solid metal substrate similar to other coatings. Each of these examples of biologic fixation surfaces has limitations. With comparatively low porosity, bead, fiber metal and plasma spray coatings are simply a surface enhancement onto a rigid machined, forged or cast metal substrate. Furthermore, the thermal process to apply the coatings can adversely affect the mechanical properties of the metal substrate. Released in the 1990's, tantalum porous metal is considered a ‘highly porous metal’ with twice the porosity of the applied surface coatings. With that greater porosity comes lower strength that requires engineers to make standalone tantalum porous metal shapes more bulky. The chemical deposition process to produce tantalum porous metal shapes has also limitations on geometry possibilities. Where bonding the tantalum porous metal to a solid metal substrate is necessary for adequate strength, that diffusion bonding process pressure can diminish the surface coefficient of friction necessary for initial stability.

A new class of manufacturing processing, referred to as ‘additive manufacturing’, allows engineers to create unique porous configurations. These configurations can be fabricated with beneficial properties to a specific implant application. One such enabling additive manufacturing process is called direct metal laser sintering (DMLS). This process utilizes a laser that travels over a fine powder bed. The laser path is determined by a program that mimics a computer model. Where the laser contacts the powder bed, the powder consolidates. Layer by layer, a scaffold porous metal is fabricated. Figure 2 shows a titanium alloy porous metal structure produced by DMLS. This formed biomaterial has 65% porosity, a high coefficient of friction, low stiffness, and strength that is 2 to 3 times that of tantalum porous metal. From a design versatility perspective, with greater strength, relatively thinner and more bone conserving geometries can be developed. When a solid metal surface interface to secure a modular polymer bearing is required, the DMLS process can produce the solid surface and the porous metal at the same time. With no secondary bonding thermal cycle needed, the construct's mechanical integrity is not compromised. Advancing biologic fixation necessitates bone conserving implant designs that have the properties to achieve immediate mechanical stability and longer term bone ingrowth. This novel use of DMLS in this particular porous metal geometry allows engineers to meet those criteria.

The most common bacteria in orthopaedic prosthetic infections are Staphylococcus, namely Staphylococcus Epidermidis (SE) and Staphylococcus Aureus (SA). Infection causes implant failure due to biofilm production. Biofilms are produced by bacteria once they have adhered to a surface.

Nanotopography has major effects on cell behaviour. Our research focuses on bacterial adhesion and biofilm formation on nanofabricated materials. Bacteria studied were clinically relevant from an orthopaedic perspective, SA and SE. We hypothesise that that nanosurfaces can modulate bacterial adherence and biofilm formation and may reduce orthopaedic implant infection rate.

Isolated bacteria were grown and growth conditions optimised. Bacterial concentrations were calculated by using qPCR. Statistical analysis allowed identification of optimal biofilm growth conditions. These were refined on standard, non-nanopatterned surfaces, and then control and nanopatterned polystyrene (nanopits) and titanium plates (nanowires). Adhesion analysis was performed using fluorescence imaging and quantitative PCR.

4 bacterial strains were isolated and cultured. Growth kinetics based on 24hr cultures allowed isolation of optimal media for biofilm conditions (Dulbecco's Modified Eagle Medium with additional supplements). Highest bacterial concentrations were found following 2hrs incubation with Lysozyme during qPCR. Bacterial concentration significantly increased between 30, 60 and 90 minutes incubation. Differences in percentage coverage on different polysyrene nanosurfaces (nanopits) were noted varying. This was confirmed by qPCR extractions that showed different bacterial concentrations on different nanopatterns. Titanium nanowire surfaces significantly increased bacterial adhesion (P<0.05).

Our study cultured and quantified bacterial biofilm and suggests that by altering nanotopography, bacterial adhesion and therefore biofilm formation can be affected. Specific nanopatterned surfaces may reduce implant infection associated morbidity and mortality. Clearly this is of significant benefit to the patient, the surgeon and the NHS, and may well extend far beyond the realms of orthopaedics.

Lavage and preparation of the cancellous bony surface can facilitate adequate fixation of components in cemented total knee arthroplasty (TKA). Commonly used techniques for bone preparation such as pulse lavage, apart from adding to the cost, may cause local loss of loose cancellous bone and may even drive contaminants deeper into the tissue when used during TKA. We describe a simple, inexpensive and effective tool of using a sterilised toothbrush for preparing bone surface during cemented TKA. This must be followed by adequate pressurization of cement at the right time to achieve close interdigitation of cement with trabecular bone.

Aim

To asses the accuracy of total knee replacements performed using CT based patient specific instrumentation by postoperative CT scan.

INTRODUCTION

Soft tissue balancing in knee arthroplasty remains an art. To make it a science reliable quantification and reference values for soft tissue tension and contact loads are necessary. This study intends to prove the concept of a compartmental load safe target zone as a clinical tool for balancing total knee arthroplasties by studying the relationship between post- balancing compartmental load distribution and patient satisfaction at 6 months.

Soft tissue balance and alignment have long been known to play an essential role in the long-term success of primary total knee arthroplasty (TKA). Until recently balance was confirmed based on intra-operative feel and experience. In this study we analyzed short-term outcomes of cruciate retaining TKA (CR-TKA) performed with a smart tibial trial device (STT), which provides real-time, intra-operative compartmental load and rotational congruency readings, to a comparable cohort of patients receiving conventional TKA where the same surgeon balanced the compartments based on feel and experience.

Seventy patients received CR-TKA with STT and were matched to one-hundred and eighty non-STT consecutive controls using the same anesthesia, surgical approach, and post-operative rehabilitation and pain management protocol. Both groups were evaluated preoperatively and then post-operatively at three months and one year using Short Form 12 (SF12) and the Western Ontario and McMaster University Osteoarthritis Index (WOMAC) questionnaires. T-tests were used to compare average scores within each cohort, as well as between the two cohorts, for each time interval.

The average age and BMI for the STT cohort were 70.9 ± 9.2 years and 29.8 ± 6.1 kg/m². Operation length was seen to be 12.0 minutes greater for the STT cohort compared to the conventional cohort (p = 0.0012). The average difference in pressure between medial and lateral compartments was 8.30, 11.49, and 8.65 lbs at 10°, 45°, and 90° respectively. Only 10 cases had a difference greater than 15 lbs between compartments. At 3 months, the STT cohort had significantly higher average function scores on the WOMAC (p=0.046) and higher change from baseline pain scores on the WOMAC (p=0.0016). When scores were stratified into the top 50% and the bottom 50% and the coronal balance was compared, SF12 pain scores and WOMAC function scores at 1 year in the top 50% had greater coronal balance indicated by pressure differences ≤ 15 lbs (p<0.002)

Given the results of this case-control study, we conclude that STT can indeed help the surgeon balance compartmental loads and femoral-tibial rotational congruency and lead to improved short-term physical and functional outcomes in primary CR-TKA.