Malalignment is often postulated as the main reason for the high failure rate of total ankle replacements (TARs). Only a few studies have been performed to correlate radiographic TAR malalignment to the clinical outcome, but no consistent trends between TAR alignment parameters and the clinical outcome were found. No standard TAR alignment measurement method is present, so reliable comparison between studies is difficult. Standardizing TAR alignment measurements and increasing measurable parameters on radiographs in the clinic might lead to a better insight into the correlation between malalignment and the clinical outcome. This study aims to develop and validate a tool to semi-automatic measure TAR alignment, and to improve alignment measurement on radiographs in the clinic. A tool to semi-automatically measure TAR alignment on anteroposterior and lateral radiographs was developed and used by two observers to measure TAR alignment parameters of ten patients. The Intraclass Coefficient (ICC) was calculated and accuracy was compared to the manual measurement method commonly used in the clinic. The tool showed an accuracy of 76% compared to 71% for the method used during follow-up in the clinic. ICC values were 0.94 (p<0.01) and higher for both inter-and intra-observer reliability. The tool presents an accurate, consistent, and reliable method to measure TAR alignment parameters. Three-dimensional alignment parameters are obtained from two-dimensional radiographs, and as the tool can be applied to any TAR design, it offers a valuable addition in the clinic and for research purposes

Prosthetic joint infection (PJI) is an important cause of arthroplasty failure. There is no method to disclose the presence or map the distribution of the in vivo biofilm on infected arthroplasty despite the recognition that such a tool would aid intraoperative decision making and improve novel implant design. The aim of this study was to test the efficacy of four dyes to disclose bacterial biofilm in an in vitro setting. Four dyes with known affinity to bacterial biofilm were assessed to determine their efficacy to disclose biofilms in an in vitro model of PJI. Three dyes (Methylene Blue, Indocyanine Green and Rose Bengal) have established clinical utility and the other, Thioflavin T, is known to fluoresce in the presence of amyloid a known biofilm constituent. The efficacy of the dyes to discriminate between biofilms of different mass and vitality (high, low or the non-inoculated control) was determined after three minutes exposure of the biofilm to the dyes by calculating the amount of dye bound to the biofilm via sonication and spectrophotometry, quantification of the dye through standardised photographic imaging of the stained biofilm and the calculation of inter-observer agreement. Each experiment was performed in triplicate for each dye and repeated three times. For each of the disclosure dyes assessed there was significant difference demonstrated between the amount of dye bound to the high and low mass biofilms (p<0.05) as well as in the amount of dye quantified in photographic and fluorescent image assessment between biofilms of differing mass (p<0.01). There was excellent agreement between three observers, for each disclosure dye, in determining the biofilm mass of each stained disc (Kappa>0.91). This study demonstrates the efficacy of biofilm disclosure dyes in an in vitro PJI model which could one day be used to disclose and map the clinical biofilm in vivo

The primary aim was to assess the reliability of ultrasound in the assessment of humeral shaft fracture healing. The secondary aim was to estimate the accuracy of ultrasound assessment in predicting humeral shaft nonunion. Twelve patients (mean age 54yrs [20–81], 58% [n=7/12] female) with a non-operatively managed humeral diaphyseal fracture were prospectively recruited and underwent ultrasound scanning at six and 12wks post-injury. Scans were reviewed by seven blinded observers to evaluate the presence of sonographic callus. Intra- and inter-observer reliability were determined using the weighted kappa and intraclass correlation coefficient (ICC). Accuracy of ultrasound assessment in nonunion prediction was estimated by comparing scans for patients that united (n=10/12) with those that developed a nonunion (n=2/12). At both six and 12wks, sonographic callus was present in 11 patients (10 united, one developed a nonunion) and sonographic bridging callus (SBC) was present in seven patients (all united). Ultrasound assessment demonstrated substantial intra- (6wk kappa 0.75, 95% CI 0.47-1.03; 12wk kappa 0.75, 95% CI 0.46-1.04) and inter-observer reliability (6wk ICC 0.60, 95% CI 0.38-0.83; 12wk ICC 0.76, 95% CI 0.58-0.91). Absence of sonographic callus demonstrated a sensitivity of 50%, specificity 100%, positive predictive value (PPV) 100% and negative predictive value (NPV) 91% in nonunion prediction (accuracy 92%). Absence of SBC demonstrated a sensitivity of 100%, specificity 70%, PPV 40% and NPV 100% (accuracy 75%). Of three patients at risk of nonunion based on reduced radiographic callus formation (Radiographic Union Score for HUmeral fractures <8), one had SBC on 6wk ultrasound (and united) and the other two had non-bridging or absent sonographic callus (both developed a nonunion). Ultrasound assessment of humeral shaft fracture healing was reliable and predictive of nonunion, and may be a useful tool in defining the risk of nonunion among patients with reduced radiographic callus formation

Anterior approach total hip arthroplasty (AA-THA) has a steep learning curve, with higher complication rates in initial cases. Proper surgical case selection during the learning curve can reduce early risk. This study aims to identify patient and radiographic factors associated with AA-THA difficulty using Machine Learning (ML). Consecutive primary AA-THA patients from two centres, operated by two expert surgeons, were enrolled (excluding patients with prior hip surgery and first 100 cases per surgeon). K- means prototype clustering – an unsupervised ML algorithm – was used with two variables - operative duration and surgical complications within 6 weeks - to cluster operations into difficult or standard groups. Radiographic measurements (neck shaft angle, offset, LCEA, inter-teardrop distance, Tonnis grade) were measured by two independent observers. These factors, alongside patient factors (BMI, age, sex, laterality) were employed in a multivariate logistic regression analysis and used for k-means clustering. Significant continuous variables were investigated for predictive accuracy using Receiver Operator Characteristics (ROC). Out of 328 THAs analyzed, 130 (40%) were classified as difficult and 198 (60%) as standard. Difficult group had a mean operative time of 106mins (range 99–116) with 2 complications, while standard group had a mean operative time of 77mins (range 69–86) with 0 complications. Decreasing inter-teardrop distance (odds ratio [OR] 0.97, 95% confidence interval [CI] 0.95–0.99, p = 0.03) and right-sided operations (OR 1.73, 95% CI 1.10–2.72, p = 0.02) were associated with operative difficulty. However, ROC analysis showed poor predictive accuracy for these factors alone, with area under the curve of 0.56. Inter-observer reliability was reported as excellent (ICC >0.7). Right-sided hips (for right-hand dominant surgeons) and decreasing inter-teardrop distance were associated with case difficulty in AA-THA. These data could guide case selection during the learning phase. A larger dataset with more complications may reveal further factors

Glenoid and humeral head bone defects have long been recognized as major determinants in recurrent shoulder instability as well as main predictors of outcomes after surgical stabilization. However, a universally accepted method to quantify them is not available yet. The purpose of the present study is to describe a new CT method to quantify bipolar bone defects volume on a virtually generated 3D model and to evaluate its reproducibility. A cross-sectional observational study has been conducted. Forty CT scans of both shoulders were randomly selected from a series of exams previously acquired on patients affected by anterior shoulder instability. Inclusion criterion was unilateral anterior shoulder instability with at least one episode of dislocation. Exclusion criteria were: bilateral shoulder instability; posterior or multidirectional instability, previous fractures and/or surgery to both shoulders; congenital or acquired inflammatory, neurological, or degenerative diseases. For all patients, CT exams of both shoulders were acquired at the same time following a standardized imaging protocol. The CT data sets were analysed on a standard desktop PC using the software 3D Slicer. Computer-based reconstruction of the Hill-Sachs and glenoid bone defect were performed through Boolean subtraction of the affected side from the contralateral one, resulting in a virtually generated bone fragment accurately fitting the defect. The volume of the bone fragments was then calculated. All measurements were conducted by two fellowship-trained orthopaedic shoulder surgeons. Each measurement was performed twice by one observer to assess intra-observer reliability. Inter and intra-observer reliability were calculated. Intraclass Correlation Coefficients (ICC) were calculated using a two-way random effect model and evaluation of absolute agreement. Confidence intervals (CI) were calculated at 95% confidence level for reliability coefficients. Reliability values range from 0 (no agreement) to 1 (maximum agreement). The study included 34 males and 6 females. Mean age (+ SD) of patients was 36.7 + 10.10 years (range: 25 – 73 years). A bipolar bone defect was observed in all cases. Reliability of humeral head bone fragment measurements showed excellent intra-observer agreement (ICC: 0.92, CI 95%: 0.85 – 0.96) and very good interobserver agreement (ICC: 0.89, CI 95%: 0.80 – 0.94). Similarly, glenoid bone loss measurement resulted in excellent intra-observer reliability (ICC: 0.92, CI 95%: 0.85 – 0.96) and very good inter-observer agreement (ICC: 0.84, CI 95%:0.72 – 0.91). In conclusion, matching affected and intact contralateral humeral head and glenoid by reconstruction on a computer-based virtual model allows identification of bipolar bone defects and enables quantitative determination of bone loss

Surgical microfracture is considered a first line treatment for talar osteochondral defects. Pain reduction, functional improvement and patient satisfaction are described to be 61–86% in both primary and secondary osteochondral defects. However, limited research is available whether improvement of the surgical technique is possible. We do know that the current rigid awls and drills limit the access to all locations in human joints and increase the risk of heat necrosis of bone. Application of a flexible water jet instrument to drill the microfracture holes can improve the reachability of the defect without inducing thermal damage. The aim of this study is to determine whether water jet drilling is a safe alternative compared to conventional microfracture awls by studying potential side effects and perioperative complications, as well as the quality of cartilage repair tissue in a caprine model. 6 mm diameter talar chondral defects were created bilaterally in 6 goats (12 samples). One defect in each goat was treated with microfracture holes created with conventional awls. The contralateral defect was treated with holes created with 5 second water jet bursts at a pressure of 50 MPa. The pressure was generated with a custom-made setup using an air compressor connected to a 300 litre accumulator that powered an air driven high-pressure pump (P160 Resato, Roden, The Netherlands, . www.resato.com. ). Postoperative complications were recorded. After 24 weeks, analyses were performed using the ICRS macroscopic score and the modified O'Driscoll histological score. Wilcoxon ranked sum tests were used to assess significant differences between the two instrument groups using each goat as its own control (p ≤ 0.05). One postoperative complication was signs of a prolonged wound healing with swelling and reluctance to weight bearing starting two days after surgery on the water jet side. Antibiotics were administered which resolved the symptoms. The median total ICRS score for the tali treated with water jets was 9,5 (range: 6–12) and 9 (range 2–11) for Observer 1 and 2 respectively; and for the tali treated conventionally this was 9,5 (range 5–11) and 9 range (2–10). The median total Modified O'Driscoll score for the tali treated with water jets was 15 (range: 7–17) and 13 (range: 3–20) for Observer 1 and 2 respectively; and for the tali treated conventionally was 13 (range: 11–21) and 15 (range: 9–20). No differences were found in complication rate or repair tissue quality between the two techniques. The results suggest that water jet drilling can be a safe alternative for conventional microfracture treatment. Future research and development will include the design of an arthroscopic prototype of the water jet drill. The focus will be on stability in nozzle positioning and minimized sterile saline consumption to further the decrease the risk of soft tissue damage

Summary. The ankle X-ray has moderate diagnostic power to identify syndesmotic instability, showing large sensitivity ranges between observers. Classification systems and radiographic measurements showed moderate to high interobserver agreement, with extended classifications performing worse. Introduction. There is no consensus regarding the diagnosis and treatment of ankle fractures with respect to syndesmotic injury. The diagnosis of syndesmotic injury is currently based on intraoperative findings. Surgical indication is mainly made by ankle X-ray assessment, by several classification systems and radiographic measurements. Misdiagnosis of the injury results in suboptimal treatment, which may lead to chronic complaints, like instability and osteoarthritis. This study investigates the diagnostic power and interobserver agreement of three classification methods and radiographic measures, currently used to assess X-ankles and to identify syndesmotic injury. Patients and Methods. Twenty patients (43.2 ± 15.3yrs) with an ankle fracture, indicated for surgery, were prospectively included. All patients received a preoperative ankle X-ray, which was assessed by several observers: two orthopaedic surgeons, one trauma surgeon and two radiologists. The ankle X-ray was assessed on syndesmotic injury/stability and presence of fractures (fibula, medial/tertius malleolus). Three classification systems were used: Weber, AO-Müller (short-version n=3 options; extended-version n=27 options), Lauge-Hansen (short-version n=5 options; extended-version n=17 options) and two radiographic measurements were done: tibiofibular overlap (TFO) and ratio medial clearspace/superior clear space (MCS/SCS). All observers were instructed about the assessments before the measurements. During surgery, a proper intraoperative description of the syndesmosis was noted. Agreement (%), Intraclass Correlation Coefficients (ICC) and Kappa were calculated to determine interobserver agreement. Kappa statistic was interpreted according to Landis and Koch. To test the diagnostic power of ankle X-rays to identify syndesmotic instability, sensitivity and specificity were calculated with intraoperative findings serving as golden standard. Results. Six of 20 ankles showed syndesmotic instability intraoperatively. An overall sensitivity of 43% (specificity: 78) was found for X-rays in identifying syndesmotic instability, showing a wide range in sensitivity between observers (17–83%), with radiologists performing better (range 50–83%) than surgeons (range: 17–33%). Overall, substantial to perfect interobserver agreement (range 70–100%) was found for all short classification systems, showing an average kappa ≥0.60. The agreement reduced for more extended classification systems. E.g. observer agreement for the AO-Muller classification with 3, 9 and 27 options was respectively 85% (kappa 0.66), 68% (kappa 0.57) and 55% (kappa 0.51). One observer deviated slightly from others in all classification assessments. Removing this observer resulted in excellent agreement for all classification systems (>90%). Radiographic measurements showed moderate to high interobserver agreement, with TFO performing best (avg. ICC 0.88). Discussion/Conclusion. In ankle fractures, a preoperative X-ray has low sensitivity in detecting syndesmotic instability, showing large sensitivity ranges between observers. Further study is needed to investigate the contribution of classification systems in determining the best treatment method for syndesmotic injury. Ankle X-ray assessment using the three classification systems and radiographic measures was consistent among observers. Disagreement between observers can be attributed to intrinsic differences among the systems (e.g. stepwise classification vs. single assessment). No preference for one specific classification was found, as all showed comparable interobserver agreement. However classification systems with few options are recommended, as the observer agreement reduced with more extending classifications

Introduction and Objective. After anterior cruciate ligament reconstruction one of the risk factors for graft (re-)rupture is an increased posterior tibial slope (PTS). The current treatment for PTS is a high tibial osteotomy (HTO). This is a free-hand method, with 1 degree of tibial slope correction considered to be equal to 1 or even 1.67 mm of the anterior wedge resection. Error rates in the frontal plane reported in literature vary from 1 – 8.6 degrees, and in the sagittal plane outcomes in a range of 2 – 8 degrees are reported when planned on PTSs of 3 – 5 degrees. Therefore, the free-hand method is considered to have limited accuracy. It is expected that HTO becomes more accurate with patient specific saw guides (PSGs), with an accuracy margin reported in literature of 2 degrees. This proof of concept porcine cadaver case study aimed to investigate whether the use of PSGs improves the accuracy of HTO to less than 2 degrees. Secondly, the reproducibility of tibial slope measurement was evaluated. Materials and Methods. Preoperative MRI images of porcine cadaver knees (n = 3) were used to create 3D anatomical bone models (Mimics, Materialise, Belgium). These 3D models were subsequently used to develop PSGs (3-Matic, Materialise, Belgium) to correct all tibias for 3 degrees PTS and 4 degrees varus. The PSG mediated HTOs were performed by an experienced orthopaedic surgeon, after which postoperative MRI images were obtained. 3D anatomical models of postoperative tibias were created, and tibial slopes were assessed on both pre- and postoperative tibias. The tibial slope was defined as the angle between the mechanical axis and 3D tibial reference plane in the frontal and sagittal plane. The accuracy of the PSG mediated HTO (median and range) was defined as the difference in all possible combinations of the preoperatively planned and postoperatively obtained tibial slopes. To ensure reproducibility, the pre- and postoperative tibial slopes were measured thrice by one observer. The intra-class correlation coefficients (ICCs) were subsequently calculated to assess the intra-rater reliability (SPSS, IBM Corp., Armonk, N.Y., USA). Results. An accuracy within 2 degrees was achieved in all three cases. The median and range in accuracy for each specimen were +0.46 (−0.57 – 1.45), +0.60 (−1.07 – 1.00), and +0.45 (−0.16 – 0.71) degrees in the frontal plane, and −0.45 (−1.97 – 1.22), −0.80 (−2.42 – 1.77), and 0.00 (−2.19 – 1.93) degrees in the sagittal plane. The pre- and postoperatively planned tibial slopes in the frontal and sagittal plane were measured with a good up to excellent reproducibility. The ICCs of the preoperative planned tibial slopes were 0.82 (95% CI, 0.11 – 1.0), and 0.77 (95% CI, 0.17 – 1.0) for the frontal and sagittal plane, respectively. Postoperative, the ICC for the frontal plane was 0.92 (95% CI, 0.43 – 1.0), and 0.67 (95% CI, −0.06 – 0.99) for the sagittal plane. Conclusions. This proof of concept porcine case study showed an accuracy for the PSG mediated HTO within 2 degrees for each specimen. Moreover, the tibial slopes were measured with a good up to excellent reproducibility. Therefore, the PSG mediated HTO seems to be accurate and might be better than the current used free-hand HTO method. These results offer perspective for implementation of PSG mediated HTO to correct PTS and metaphyseal varus

Background. Positioning of the acetabular component in total hip arthroplasty has profound effects on the biomechanics, stability and wear of the prosthesis. Normal anatomical position in females is 57 degrees (50 – 67 degrees) inclination with 19 degrees (9 – 32 degrees) of anteversion, whilst in males 56 degrees of inclination (48 – 66 degrees) with 19 degrees (9 – 32 degrees) is normal. In total hip arthroplasty, inclination recommendation ranges from 30 – 50 degrees. The aim of this study was to radiographically measure acetabular component position in total hip arthroplasty and compare to normal values. Method. The Widmer method was used by two independent observers to radiographically measure inclination in 522 patients using standard AP radiographs. Primary measures and variables were statistically analysed as was inter and intra observer reliability. All patients included within the study received total hip arthroplasty for age related degenerative changes to the hip. Operations were undertaken by 17 separate consultants or senior registrars under their care. Results. Overall mean inclination was measured at 45.27 degrees with a range of 26 – 68 degrees. Statistically significant differences were observed between cemented 45.9o and non-cemented hips 43.9 degrees (p= 0.018), Simple 45.5 degrees vs complex 42.1 degrees (p=0.003) and Male 44.3 degrees vs Female 46.2 degrees (p=0.0198). No statistical difference was seen between consultant and registrar (p=0.211) and right vs left (p=0.768). Inter observer reliability was seen to be 0.91 whilst intra observer reliability 0.96. Conclusion. Although a large range of outcomes were observed, 95% of radiographs reviewed fell within a range of 33.6 – 56.9 degrees Variables such as surgical positioning, patient anatomy/body habitus, surgical technique, instrumentation likely influenced abnormal results. Abnormal positioning may have effects such as eccentric wear and dislocation, however, and such findings are yet to be observed in the study group

Abstract. Background. Lower limb mechanical axis has long been seen as a key to successful in lower limb surgery, including knee arthroplasty. Traditionally, coronal alignment has been assessed with weight-bearing lower limb radiographs (LLR) allowing assessment of hip-knee-ankle alignment. More recently CT scanograms (CTS) have been advocated as a possible alternative, having the potential benefits of being quicker, cheaper, requiring less specialist equipment and being non-weightbearing. Objectives. To evaluate the accuracy and comparability of lower limb alignment values derived from LLR versus CTS. Methods. We prospectively investigated patients undergoing knee arthroplasty with preoperative and postoperative LLR and CTS, analysing both preoperative and postoperative LLRs & CTS giving 140 imaging tests for direct comparison. We used two independent observers to calculate on each of imaging modalities, on both pre- and post-operative images, the: hip-knee-ankle alignment (HKA), lateral distal femoral angle (LDFA) and medial proximal tibial angle (MPTA). Results. 840 data points were captured from pre- and post-operative LLRs and CTSs. Analysis demonstrated very strong correlation in pre-operative HKA (LLR vs CTS, r = 0.917), post-operative HKAs (LLR vs CTS, 0.850) and postoperative LDFAs (LLR vs CTS, 0.850). Strong correlation was observed in pre-operative LDFAs (0.732), MPTAs (0.604), and post-operative MPTAs (0.690). Conclusion. Both pre- and post-operative LLR and CTS imaging display very strong correlation for HKA coronal alignment correlation, with strong correlation for other associated angles around the knee. Our results demonstrate that both LLR and CTS can be used interchangeably with similar results. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Driven by increasing emphasis on problem-based and self-directed learning, medical students and doctors in orthopedic specialty training rely increasingly on the internet as learning resource. As students or residents performance on physical examination may be less supervised in comparison to other clinical skills (for example surgical competence), online videos may provide a valuable source for education of physical examination skills. Cognitive psychological research has shown that videos can help viewers to understand techniques and manage the sequential steps of physical examination and approach to patients. YouTube is the largest open-access video platform available and provides access to thousands of educational videos on orthopedics-related topics. VuMedi, G9MD, and Orthobullets are examples of online platforms requiring user-registration with video content that is more directly focused on orthopedic topics. The objective of this study was to investigate the accuracy and quality of instructional videos on the physical examination of the elbow and identify factors influencing the educational usefulness. A YouTube, VuMedi, Orthobullets, and G9MD search was performed on October 7, 2018 for videos on the physical examination of the elbow. We included both basic examination and disease specific tests. The included videos were rated for accuracy and quality by two independent authors using a modified version of a validated scoring system. Inter-rater reliability was analyzed using mean difference and intra-class correlation coefficient. Twenty-three out of 126 videos were indicated as useful for educational purposes. Accuracy, quality and total scores were statistically significant higher for videos from specialized platforms compared to YouTube: 16.5 (95% CI 16 to 17) vs. 12.816 (95% CI 12.3 to 13.3) respectively. Video accuracy and quality were highly variable and did not correlate. The number of days online, views, and likes showed no or weak correlation with accuracy and quality. For the total score, our assessment tool showed excellent inter-rater reliability of 0.93 (95% CI 0.09–0.95) and a mean difference of 0.024 point between the two observers (p=0.871). There is considerable variation in accuracy and quality of online available videos on the physical examination of the elbow. We indicated 23 educationally useful videos and provided an assessment method. This assessment method can be useful for both viewers to assess reliability of a video and educators interested in creating videos

Osteoarthritis (OA) is a progressive and degenerative joint disease resulting in changes to articular cartilage. In focal early OA defects, autologous chondrocyte implantation (ACI) has a 2-fold failure rate due to poor graft integration and presence of inflammatory factors (e.g. Interleukin-1β). Bone marrow derived mesenchymal stem cells (MSCs) are an alternative cell source for cell-based treatments due to their chondrogenic capacity, though in vivo implantation leads to bone formation. In vivo, chondrocytes reside under an oxygen tension between 2–7% oxygen or physioxia. Physioxia enhances MSC chondrogenesis with reduced hypertrophic marker (collagen X and MMP13) expression compared to hyperoxic conditions (20% oxygen). This study sought to understand whether implantation of physioxic preconditioned MSCs improves cartilage regeneration in an early OA defect model compared to hyperoxic MSCs. Bone marrow extracted from New Zealand white rabbits (male: 5–6 months old; n = 6) was split equally for expansion under 2% (physioxia) or 20% (hyperoxia) oxygen. Chondrogenic pellets (2 × 105 cells/pellet) formed at passage 1 were cultured in the presence of TGF-β1 under their expansion conditions and measured for their wet weight and GAG content after 21 days. During bone marrow extraction, a dental drill (2.5mm diameter) was applied to medial femoral condyle on both the right and left knee and left untreated for 6 weeks. Following this period, physioxia and hyperoxia preconditioned MSCs were seeded into a hyaluronic acid (TETEC) hydrogel. Fibrous tissue was scraped and then MSC-hydrogel was injected into the right (hyperoxic MSCs) and left (physioxia MSCs) knee. Additional control rabbits with drilled defects had fibrous tissue scrapped and then left untreated without MSC-hydrogel treatment for the duration of the experiment. Rabbits were sacrificed at 6 (n = 3) and 12 (n = 3) weeks post-treatment, condyles harvested, decalcified in 10% EDTA and sectioned using a cryostat. Region of interest was identified; sections stained with Safranin-O/Fast green and evaluated for cartilage regeneration using the Sellers scoring system by three blinded observers. Physioxic culture of rabbit MSCs showed significantly shorter doubling time and greater cell numbers compared to hyperoxic culture (∗p < 0.05). Furthermore, physioxia enhanced MSC chondrogenesis via significant increases in pellet wet weight and GAG content (∗p < 0.05). Implantation of physioxic preconditioned MSCs showed significantly improved cartilage regeneration (Mean Sellers score = 7 ± 3; ∗p < 0.05) compared to hyperoxic MSCs (Sellers score = 12 ± 2) and empty defects (Sellers score = 17 ± 3). Physioxia enhances in vitro rabbit MSC chondrogenesis. Subsequent in vivo implantation of physioxia preconditioned MSCs improved cartilage regeneration in an early OA defect model compared to hyperoxic MSCs. Future studies will investigate the mechanisms for enhanced in vivo regeneration using physioxia preconditioned MSCs

The use of antifibrinolytic drugs and many other agents have a critical importance in bleeding control. Tranexamic acid [4- (aminomethyl) cyclohexanecarboxylic acid] is a synthetic amino acid lysine derivative with antifibrinolytic activity in humans. There are many studies in the literature that show that it is effective and effective both systemically and locally in spinal surgery. However, all of these studies have investigated the effects of topical tranexamic acid on bleeding and its effect on fusion has not been investigated yet. Aim of this study is to investigate the effect of topical tranexamic acid on fusion using macroscopic, radiologic and microscopic techniques. After approve of ethics committee with the protocol number 19/2019 for 28 Wistar Albino rats underwent intertransvers fusion. All rats were randomized into four (4) groups, using sealed envelopes. Local tranexamic acid (Transamin® 100 mg/ml, Teva İlaç, İstanbul) doses was determined based on previously conducted studies; 1mg/kg (D1 group), 10mg/kg (D10 group), 100 mg/kg (D100 group) and no tranexamic acid (D0 group). At the end of 8. th. weeks all rats were evaluated with manuel palpation, mammography and histopathologic analysis. Radiographic examination was performed two times to evaluate the intra and inter observer differences. 2 rats in-group D0 died after the radiographic examination. Assessment of fusion with manual palpation revealed that use of local 1mg / kg tranexamic acid had no effect on fusion (p=0.32), however with increasing doses of tranexamic acid had negative effect on fusion (p=0.002). On radiologic examination, spearman's rho correlation coefficient was found to be moderate in the first evaluation (r=0.46) and high in second evaluation (r=0.61). Radiological examination revealed that the control group was the best in fusion (p=0.007), and that tranexamic acid affected fusion adversely, independent of dosage (p=0.27). Among the groups in histopathologic examination, no statistical difference was found (p=0.134). Local administration of tranexamic acid affects the intertransverse fusion adversely depending on the dosage macroscopically and it also affects fusion adversely independent of the dosage radiologically and histopathologically

Summary. The EOS stereography system has been developed for the evaluation of prosthetic alignment. This new low-dose device provides reliable 2D/3D measurements of knee prosthesis alignment. Introduction. Achieving optimal prosthetic alignment during Total Knee Arthroplasty (TKA) is an essential part of the surgical procedure since malpositioning can lead to early loosening of the prosthesis and eventually revision surgery. Conventional weight-bearing radiographs are part of the usual clinical follow-up after both primary TKA and revision TKA (rTKA), to assess alignment in the coronal and sagittal planes. However, proportions and angles may not be correct on radiographs since divergence exists in the vertical and horizontal planes. Furthermore estimating the exact planes by looking at the position of the patella depends on rotation in the hip joint and this may be misinterpreted by the investigator. A computed tomography (CT) scanogram can also be used. However, due to high levels of radiation and costs it is not routinely used. To this end, a new device, the EOS stereography system, has been developed. With this biplanar low-dose X-ray technique, orthogonally made 2D images and 3D reconstructions can be obtained. Advantages of EOS are that images of the leg are obtained on a 1:1 scale with an amount of radiation 800–1000 times lower than CT-scans and 10 times lower than conventional radiographs. Another advantage is that the 3D reconstructions lead to determination of the real coronal and sagittal planes. However, the software for creating 3D reconstructions is developed for the lower limbs without knee prosthesis material. Consequently a reliability study concerning the generation of 2D images and 3D reconstructions of a leg containing a knee prosthesis has not been performed yet. Therefore objective of this study was to investigate interobserver and intraobserver reliability of knee prosthetic alignment measurements after rTKA using EOS. Patients and Methods. Forty anteroposterior and lateral images of 37 rTKA patients were included. Two observers independently performed measurements on these images twice. Measured angles were varus/valgus angle in 2D (VV2D) and 3D (VV3D). Intraclass correlation coefficients (ICCs) were used to determine relative reliability and the Bland and Altman method was used to determine absolute reliability. T-tests were used to test potential differences between the two observers, first and second measurement sessions and 2D and 3D measurements. Results. Relative interobserver reliability was excellent for both VV2D and VV3D with ICCs > 0.95, and no significant differences between the two observers. For the absolute reliability of VV2D, a bias of −0.16° (95%CI: −0.31–0.01) existed between both observers. Absolute reliability of VV3D was good. Relative intraobserver reliability was excellent for both VV2D and VV3D with ICCs > 0.97. No significant difference and no bias between the first and second measurements were found. A significant difference existed between the angles measured in 2D and 3D (p=0.01). Discussion / Conclusion. The EOS low-dose stereography system provides reliable varus/valgus measurements in 2D and 3D for the alignment of the knee joint with a knee prosthesis. However, significant differences exist between the varus/valgus measurements in 2D and in 3D. Therefore, a validation study is suggested to investigate the difference between the 2D measurements and 3D reconstructions and to find a possible explanation for this difference

This study measured the three bony axes usually used for femoral component rotation in total knee arthroplasty and compared the accuracy and repeatability of different measurement techniques. Fresh cadaveric limbs (n=6) were used. Three observers (student, trainee and consultant) identified the posterior condylar (PCA), anteroposterior (AP) and the transepicondylar (TEA) axes, using a computer navigation system to record measurements. The AP axis was measured before and after being identified with an ink line. The TEA was measured by palpation of the epicondyles both before and after an incision was made in the medial and lateral gutters at the level of the epicondyles, allowing the index finger to be passed behind the gutters. In addition the true TEA was identified after dissection of all the soft tissues. Each measurement was repeated three times. For all axes and each observer the repeatability coefficient was calculated. The identification of the PCA was the most reliable (repeatability coefficient: 1.1°) followed by the AP after drawing the ink line (4.5°) then the AP before (5.7°) and lastly the TEA (12.3°) which showed no improvement with the incisions (13.0°). In general the inter-observer variability for each axis was small (average 3.3°, range 0.4° to 6°), being best for the consultant and worst for the student. In comparison to the true TEA, the recorded TEA and AP axis averaged within 1.5° whilst the PCA was consistently 2.8° or more internally rotated. This study echoed previous studies in demonstrating that palpating the PCA intra-operatively is highly precise but was prone to errors in representing the true TEA if there was asymmetrical condylar erosion. The TEA was highly variable irrespective of observer ability and experience. The line perpendicular line to the AP axis most closely paralleled the true TEA when measured after being identified with an ink line

Summary. A single 3D accelerometer is accurate in measuring upper-extremity activity durations, rest periods and intensities, suggesting its feasibility for daily life measurements with patients. Further enhancements are feasible to reduce residual false classifications of intensity from certain activities. Introduction. Physical activity is an important outcome measure in orthopaedics as it reflects how surgically restored functional capacity is used in daily life. Accelerometer-based activity monitors (AM) are objective, reliable and valid to determine lower extremity activity in orthopaedic patients. However the suitability of a single AM to monitor upper-extremity activity, in terms of quantity and intensity, has not been investigated. This study investigates the suitability and validity of a single AM to measure quantity and intensity of upper-extremity activity. Method. Five healthy young subjects (25 ± 3 yrs) were included. Subjects underwent a standardised protocol consisting of walking, combing hair, cleaning a desk while standing, brushing teeth and cleaning a window. All one-handed activities were performed with the right arm, as all subjects were right handed. The activities were performed in a fixed order, at self selected speed, for at least 30s. Between the activities, subjects stood still for 10s with their arms next to the body. A light-weight (18g) 3D-accelerometer (f=40Hz) was taped to the right elbow, just above the base of the Hueter triangle, using double sided tape. During the measurement, patients were recorded by a video camera analyzed by an independent human observer as validation reference. AM data and video-recordings were analyzed per second. The time being active (% of time) was determined over the whole measurement and for every activity separately, the percentage of the active time spend in high and low intensity was determined. Video-recording and AM-output were compared by determining Mean Percentage Error (MPE) and the accuracy (100-MPE). Results. High agreement in measuring upper-extremity (in-) activity was found between AM and video-recordings, showing an accuracy of 93%. Except for walking and combing hair, high agreement between AM and video-recordings was found in measuring activity intensity (accuracy range: 83–100%). 97% of walking was misclassified: video-recordings classify walking as low intensity, the AM as high intensity. Low agreement (58% agreement) for intensity was also found for combing hair. Discussion and Conclusion. A single AM is accurate in measuring the duration of upper-extremity activity and rest periods in healthy subjects under controlled circumstances. This suggests the suitability of AM to monitor real life upper-extremity activity, which can serve as objective clinical outcome in patients with shoulder complaints. Beyond durations, the AM seems also suitable for measuring activity intensity, showing high accuracy for most activities. The low accuracy in intensity classification of walking and combing hair can be explained by the different interpretations of intensity by observer and AM. For the observer, intensity classification may be force-related (feeling a resistance may refer to high intensity), while intensity classification is acceleration-related for the AM. The false classification of shoulder movement during walking as intense can be resolved by dedicated filters in the detection algorithms. Future algorithms will allow measurement of arm elevations (elbow below/above shoulder) which may be another relevant outcome parameter. However, already this basic AM application validated here may help e.g. in therapeutic decision making, in evaluating therapy effects or providing biofeedback

Restoration of anatomy is paramount in total hip arthroplasty (THA) to optimise function and stability. Leg-length discrepancy of ≥10mm is poorly tolerated and can be the subject of litigation. We routinely use a multimodal protocol to optimise soft tissue balancing which involves pre-operative templating, leg-length measurement supine and in the lateral position after positioning, and the use of an intra-operative leg-length measurement device to ensure optimisation of leg-length. We have analysed the results of our protocol in restoring leg-length in primary THA. Radiological leg-length was measured in a consecutive series of 50 patients who had THA for unilateral arthritis by an independent observer pre- and post-operatively using validated methods utilising radiological software. The measurements pre- and post-operative were compared. Patients with bilateral hip arthritis and poor imaging were excluded. Leg-length was successfully restored to within 5.0mm of the target leg-length in 84.0% of patients (mean +0.7mm (95% CI +0.2 to +1.1)). The other 14.0% of patients were restored to within 5.1–8.0mm (mean +2.2mm (95% CI −2.7 to +7.1)) and 2.0% of patients were restored to within 8.1–10.0mm. Leg length was accurately restored across the subset of patients within a narrow range of either side of the mean target leg length. Intra-operative measurement of leg length can be difficult but is vital in ensuring appropriate restoration of leg-length. We recommend a similar multimodal protocol to ensure restoration of leg-length within narrow limits to maximise function and patient satisfaction

Supracondylar fractures of the humerus (SCFH) are the most common type of paediatric elbow fractures. Due to beliefs that non-operatively managed SCFH may displace further from the original position, they are monitored with repeated radiographs and a large number are unnecessarily surgically pinned. Very limited evidence currently exists to support these beliefs. This study aimed to determine the incidence of late “significant” displacement (requiring surgical management) of non-operatively managed paediatric SCFH, and whether they necessitate close radiographic follow-up. Patients aged ≤16, with a SCFH, were included in this retrospective cohort study. All were initially managed non-operatively with at least one follow-up radiograph within six weeks of injury. Data from four consecutive years (2013–2016) was collected using the hospital's radiology database. Two observers independently analysed patient radiographs and classified fractures by the Gartland and AO systems. The incidence of late displacement was determined using follow-up radiographs and clinic notes. Of the 164 patients included in the study, one patient (Gartland Type II, AO Type III) suffered late displacement at two weeks, requiring surgical fixation. One further patient (AO Type II) had a persistent cubitus varus deformity (Baumann's angle 90°), with no long-term functional deficit. Incidence of late displacement was 0.6% (n=1). Our findings suggest that stable Gartland Type I/AO Type I and II fractures do not require repeated radiographic follow-up. However, some Gartland Type II/AO Type III fractures require monitoring. This could considerably reduce the financial costs for the healthcare system, and inconvenience to families, associated with repeated follow-ups

Cervical spine fractures are frequent in impact sports, such as rugby union. The consequences of these fractures can be devastating as they can lead to paraplegia, tetraplegia and death. Many studies have been conducted to understand the injury mechanisms but the relationship between player cervical spine posture and fracture pattern is still unclear. The aim of this study was to evaluate the influence of player cervical spine posture on fracture pattern due to an impact load. Nineteen porcine cervical spines (C2 to C6) were dissected, potted in PMMA bone cement and mounted in a custom made rig. They were impacted with a mean load of 6 kN. Eight specimens were tested in an axial position, five in flexion and six in lateral bending. All specimens were micro-CT imaged (Nikon XT225 ST Scanner, Nikon Metrology, UK) before and after the tests, and the images were used to assess the fracture patterns. The injuries were classified according to Allen-Ferguson classification system by three independent observers. The preliminary results showed that the main fracture modalities were consistent with those seen clinically. The main fractures for the axial orientation were observed in C5-C6 level with fractures on the articular process and endplates. These findings support the concept that the fracture patterns are related to the spine position and give an insight for improvements on sports rules in order to reduce the risk of injury

Summary. The dGEMRIC index correlates more strongly with the pattern of radiographic joint space narrowing in hip osteoarthritis at five year follow-up than morphological measurements of the proximal femur. It therefore offers potential to refine predictive models of hip osteoarthritis progression. Introduction. Longitudinal general population studies have shown that femoroacetabular impingement increases the risk of developing hip osteoarthritis, however, morphological parameters have a low positive predictive value. Arthroscopic debridement of impingement lesions has been proposed as a potential strategy for the prevention of osteoarthritis, however, the development of such strategies requires the identification of individuals at high risk of disease progression. We investigated whether delayed Gadolinium-Enhanced MRI of Cartilage (dGEMRIC) predicts disease progression. This imaging modality is an indirect measure of cartilage glycosaminoglycan content. Patients and Methods. 34 asymptomatic individuals from a longitudinal cohort study (sibkids) were assessed at baseline with the collection of Patient Reported Outcome Measures (PROMs), anteroposterior and cross-table lateral radiographs, 3D morphological MRI, and dGEMRIC at 3T of their index hip. A dGEMRIC index was calculated as a ratio of the anterosuperior acetabular cartilage T1 relaxation time and the total femoral and acetabular cartilage T1 relaxation time. 29 individuals were followed up at 5 years for repeat assessment (average age 51 years and range 36 to 67). Radiological measurements were made by a single observer using in house Hipmorf software. Radiographic disease progression was assessed using minimum joint space width (JSW), lateral sourcil JSW, and medial sourcil JSW. These were measured on baseline and five year follow-up anteroposterior radiographs with an intra-observer ICC of 0.916. Alpha angle measurements were made by the same observer on radiographs and MRI radial slices with an intra-observer ICC of 0.926. Results. Mean minimum JSW for the cohort fell by 0.16mm over five years (p=0.024). Baseline dGEMRIC index did not correlate with change in minimum JSW (r=0.031 p=0.873). There was a moderate correlation between baseline dGEMRIC and the direction of JSW loss (change in JSW at the lateral sourcil minus change in JSW at the medial sourcil) (r=0.561 p=0.002). There was a weak correlation between the change in Non-Arthritic Hip Score and baseline dGEMRIC (r=0.256 P=0.180). Maximum alpha angle measured on baseline MRI radial slices did not correlate with change in minimum JSW and weakly correlated with the direction of JSW narrowing (r=0.273 p=0.160). Conclusion. A low dGEMRIC index indicates reduced glycosaminoglycan concentration in the anterosuperior acetabular cartilage compared with the total femoral and acetabular cartilage. This correlates with lateral JSW narrowing relative to medial JSW narrowing as osteoarthritis progresses. The dGEMRIC index correlates better with osteoarthritis progression than alpha angle measurements and offers the potential to refine a predictive model for osteoarthritis progression to aid patient selection for clinical trials