Introduction. Many patients with obesity experience knee pain. Excess body weight is a modifiable risk factor for osteoarthritis (OA) and weight loss is encouraged in patients with OA. Bariatric surgery could improve or limit the progression of these conditions through significant weight loss. The Oxford Knee Score (OKS) is a validated tool in the assessment of knee replacement surgery for OA. We present a novel application of the OKS to assess knee pain & function after weight loss surgery. The primary aim of this study was to assess whether there was a significant difference in mean OKS before and 24 months after weight loss surgery. Method. Eighteen female participants were included in this study. They underwent sleeve gastrectomy or Roux-en-Y gastric bypass. Patient demographics, body mass index (BMI) and OKS were collected pre- and 24 months post operatively. Result. There was an increase in the mean OKS from 31.8 (SD 11.8) pre surgery to 36.6 (SD 12.3) at 24 months. This was statistically significant (95% CI 0.99-10.5, p=0.02). Mean BMI reduced from 46.6 kg/m. 2. (SD 5.8) to 33.0 kg/m. 2. (SD 3.5). Conclusion. A significant improvement in mean OKS was seen after weight loss surgery. These findings demonstrate an improvement in knee pain & function with weight loss. This study contributes to a larger project evaluating the kinetic and kinematic changes to walking gait from weight loss

Introduction. Weight is a modifiable risk factor for osteoarthritis (OA) progression. Despite the emphasis on weight loss, data quantifying the changes seen in joint biomechanics are limited. Bariatric surgery patients experience rapid weight loss. This provides a suitable population to study changes in joint forces and function as weight changes. Method. 10 female patients undergoing gastric bypass or sleeve gastrectomy completed 3D walking gait analysis at a self-selected pace, pre- and 6 months post-surgery. Lower limb and torso kinematic data for 10 walking trials were collected using a Vicon motion capture system and kinetics using a Kistler force plate. An inverse kinematic model in Visual 3D allowed for no translation of the hip joint centre. 6 degrees of freedom were allowed at other joints. Data were analysed using JASP with a paired samples t-test. Result. On average participants lost 28.8±7.60kg. No significant changes were observed in standing knee and hip joint angles. Walking velocity increased from 1.10±0.11 ms. -1. to 1.23±0.17 ms. -1. (t(9)=-3.060, p = 0.014) with no change in step time but a mean increase in stride length of 0.12m (SE: 0.026m; t(9)=-4.476, p = 0.002). A significant decrease of 21.5±4.2% in peak vertical ground reaction forces was observed (t(9)=12.863, p <0.001). Stride width significantly decreased by 0.04m (SE: 0.010m; t(9)=4.316, p = 0.002) along with a decrease in lateral impulse of 21.2Ns (SE: 6.977Ns; t(7), p = 0.019), but no significant difference in knee joint angles were observed. Double limb support time also significantly reduced by 0.02s (SE: 0.006s; t(9) = 3.639, p=0.005). Conclusion. The reduction in stance width and lateral impulse suggests a more sagittal compass-gait walk is being achieved. This would reduce valgus moments on the knee reducing loading in the medial compartment. The reduction in peak ground reaction force would reduce knee contact forces and again potentially slow OA progression

Purpose: To determine the extent to which, a medically monitored rapid weight-loss program will improve pain, psychological status and functional abilities for morbidly obese women with knee osteoarthritis. Method: 34 women (age 40 to 65) with morbid obesity and severe osteoarthritis of the knee that presented to an orthopedic surgeon for total knee arthroplasty were offered enrollment into a medically supervised weight loss program prior to consideration of a total knee replacement. Twenty-six subjects chose to participate in the weight loss program. They were enrolled in the Dr. Bernstein diet program, (a low-calorie, low-fat diet) at no cost to them. We collected the following questionnaires at enrollment and every six weeks while they remained in the weight loss program: WOMAC, SF36, Self-Efficacy, Health Locus of control, Dieting beliefs scale, Body image state scale, and the Beck depression inventory as well as Functional tests, namely the Timed up and go (TUG) and 6 minute walk test (6MWT). Our hypothesis was that weight loss would be associated with dramatic improvements in pain, self-report quality of life measures, psychological variables, and measured functional abilities for those patients who were successful in the weight loss program. Results: At enrollment the mean age was 58.5 years and mean BMI was 47.8. Subjects were significantly disabled with WOMAC (total) scores of 48+/ − 7 and impaired function in both the 6 minute walk test 229+/ − 146 metres and the timed up-go test 5.9+/ − 11. (table removed). Subjects lost an average of 32 kilograms (range 14 to 50 kg) after six months of dieting. Weight loss was associated with dramatic improvements in pain(p < .01), self-report quality of life measures (p < .01) and measured functional abilities (p < .01). Successful weight loss was associated with patients’ self-report of no longer requiring TKA for their knee OA. Initially 100% of subjects felt that they required surgery. This decreased to 9.5% after six months of weight loss. Conclusion: A low-fat, low-calorie medically monitored weight loss program (Dr. Bernstein Diet Clinics Inc.) is effective for achieving significant weight loss in women with severe knee osteoarthritis and morbid obesity. Weight loss leads to significant improvements in pain and functional abilities and alleviates or delays the need for knee replacement surgery in the majority of middle-aged, morbidly obese women

Background: Intensive chemotherapy in sarcoma treatment may lead to weight loss, and in turn reduce dose intensity. A possible correlation between weight loss under treatment and outcome has never been analysed in sarcoma treatment. Ewing sarcoma (ES) patients undergoing intensive non-corticosteroid-containing chemotherapy commonly experience weight loss. The German Paediatric Oncology/Haematology Society (GPOH) Ewing sarcoma trials (CESS, EICESS) registry was analysed with respect to weight loss and outcome. Patients and Methods: Body weight (BW) both at diagnosis and after a median of 12 courses of chemotherapy was available in 837 of 1549 ES patients, excluding amputees. Changes in BW were calculated as percentage of initial BW; outcome was determined as event-free-survival (EFS) from diagnosis according to Kaplan-Meier. Correlations of BW and outcome and potential confounders like disease stage or tumour volume were estimated uni- and multivariately. Results: Weight loss was not correlated with inferior outcome: A loss of 10%–20% of BW was associated with a slightly more favourable outcome (3-year EFS 0.64 +/−0.106, N=82) than weight gain of 10%–20% of BW (3-year EFS 0.58 +/−0.098, N=97), p=0.101. Multivariate analyses revealed no confounders interfering with these results. Conclusions: In 837 ES-patients analysed, weight loss did not correlate with inferior outcome. This should be observed in discussions about tube feeding and/or parenteral nutrition under cytostatic therapy. Future analyses of the prognostic impact of extreme under- or overweight both at diagnosis or under treatment are warranted in order to develop appropriate guidelines. Validity of this observation should be analysed for other solid tumours. Supported by EC Biomed and Deutsche Krebshilfe

Introduction. Osteoarthritis in the foot and ankle affects approximately 30,000 patients annually in the UK. Evidence has shown that excess weight exacerbates foot pain, with significant increases in joint forces. However, despite the current trend for Clinical Commissioning Groups to ration surgery for obese patients, studies have not yet determined the effect of weight loss in obese patients with foot and ankle arthritis. Aim. Pilot study to investigate the effect of simulated weight loss on pain scores in obese patients with symptomatic foot and ankle arthritis. Methods. Following ethical approval, a prospective study of 17 obese patients (mean BMI 39.2, range 31.2 – 50.3) with foot and ankle arthritis was undertaken (BOFAS funded). Under physiotherapist supervision, patients walked for one minute on an anti-gravity treadmill, which allowed simulated weight reduction. Following baseline assessment, reduced BMI was simulated, starting at 20, rising in increments of 5, until each patient's usual BMI was reached. Pain was assessed using a Visual Analogue Scale (VAS). Repeated measures ANOVA was used to assess for significant changes in pain, comparing baseline with each simulated BMI category (significance set at p< 0.05). Results. Simulated weight loss caused a significant reduction in pain (p=0.005, power 0.91). Mean VAS pain scores improved by 24% (p=0.003) and 17% (p=0.040) for BMI categories 20 and 25, compared with baseline. Pain scores were not significantly different comparing BMI categories of 25 and 20. Conclusion. Simulated weight loss to normal BMI significantly decreased pain in obese patients with foot and ankle arthritis. The use of the anti-gravity treadmill to demonstrate the feeling of normal BMI has also provided motivation to several patients to lose weight. The current study could be used to power future studies to investigate the effects of weight loss in foot and ankle patients

Obesity is a common in individuals undergoing arthroplasty, and the potential for weight loss with improved mobility may be expected by some. The aim of this study was 1. determine the proportion that achieved weight loss after hip or knee arthroplasty, and 2. examine the effect of obesity on patient reported outcomes (PROMS) and satisfaction with surgery. Participants underwent primary TKA or THA between July 2015 and December 2020 and consented to participation in a research database with baseline PROMS, including weight, BMI, Oxford Knee, or Hip Score, and EQ5D. Participants repeated PROMS at 12 months after surgery with additional questions regarding satisfaction with surgery. 3449 patients completed PROMS 1 year after arthroplasty with weight and BMI. There were 1810 THA and 1639 TKA procedures. The mean baseline BMI was higher in TKA (29.8, SD 5.2) compared to THA (27.7, SD 5.0), p=0.001. A higher proportion of TKA were classified as obese class 1 (29% TKA, 19% THA), obese class 2 (11% TKA and 6% THA), and obese class 3 (5% TKA and 2% THA), p=0.001. The mean weight loss after 1 year was 0.4kg and 0.9kg in obese THA subjects and TKA subjects respectively. In the obese >5kg weight loss was achieved in 13% of TKA and 7% of THA (p=0.001). Obese experienced equivalent improvement in Oxford scores, compared to non-obese subjects. Satisfaction with surgery was reported by 95% of THA and 91% of TKA subjects with no significant differences between BMI group grades (p=0.491 THA and p=0.473 TKA). Preoperative obesity was observed in 44% of TKA and 27% of THA subjects. In the obese only 1 in 10 subjects lost 5kg or more over 12 months. Obese patients experienced equivalent improvements in outcome after arthroplasty and rates of satisfaction with surgery to the non-obese

Introduction. Overwhelming evidence has established obesity as a risk factor for osteoarthritis (OA) of the knee. Randomized clinical trials such as the Look AHEAD study have shown long term successful intentional weight loss with an intensive lifestyle intervention (ILI) in overweight and obese type 2 diabetics. Weight loss can also decrease knee pain in persons who have OA, but it is unknown if intentional weight loss can reduce the risk of TKR. To answer this question, data from the Look AHEAD study were examined to determine if intentional weight loss could reduce the risk of TKR. Methods. Look AHEAD is a multicenter, randomized trial which began in August 2001 and follow-up continued for a median of 11.3 years at 16 academic centers. 5145 persons aged 45–76 with diabetes were randomized to either an ILI with reduced calorie consumption and increased physical activity designed or to diabetes support and education intervention (DSE). TKR events were ascertained every 6 months. Retrospective data of reported knee pain was assessed using the WOMAC knee pain questionnaire. Participants with partial TKR or revisions were excluded. Cox proportional hazard models were used to relate baseline BMI category (obese, Class I, Class II, or Class III obesity), baseline knee pain, and treatment group with TKR. Weight change category (lost<=5%, stable, gained>=2%) from baseline to year 1 follow-up by treatment assignment was also examined as a predictor of TKR after excluding TKR occurring prior to year 1. Results. Out of the randomized participants, 2171 reported knee pain (43%) at the baseline visit (p=0.81). WOMAC knee pain score did not differ by random assignment (ILI:3.6±2.9, DSE:3.9±3.0, p=0.08). During follow up there were 631 TKRs reported by participants. TKR was more common in heavier (p<0.001), and older (p<0.001) participants and did not differ by randomization. Heterogeneity of treatment effect was observed with baseline knee pain (interaction p = 0.02), therefore analyses were stratified by presence or absence of knee pain at baseline. In persons without knee pain at baseline, there was a 29% reduced rate of TKR in the ILI group compared to the DSE group (HR[95%CI] 0.71[0.52,0.96]; Figure 1A). Whereas in persons with knee pain at baseline, there was a trend for the ILI to have an increased rate of TKR compared to DSE (1.11[0.92, 1.33]; Figure 1B). In both sets of analyses, obese participants had significantly higher hazard of TKR than overweight participants (No pain: Class I 1.78[1.04,3.05], Class II 2.27 [1.31,3.94], Class III 2.94[1.67,5.18]; With pain: Class I 1.70[1.12,2.59], Class II 2.42 [1.60,3.65], Class III 2.80[1.85,4.23]). When TKR incidence was examined by weight change at year 1 there was no difference in weight change category between randomization groups in persons with knee pain (interaction p=0.20) or without baseline knee pain (interaction p=0.87) (Figure 1C and D) or for the overall effect of year 1 weight loss category in either stratum (with knee pain p=0.26, without knee pain p=0.48). However, in persons without knee pain at baseline, ILI had a marginal reduction in hazard of TKR compared to DSE (0.71[0.49, 1.05]) but not in the group with baseline knee pain. Conclusions. In persons with no knee pain at baseline and who were overweight or had Class I or II obesity, ILI seemed to reduce the risk of TKR compared to DSE. In contrast, persons with knee pain who gained weight at 1 year and were randomized to ILI had the highest risk of TKR. This suggests that weight loss to prevent TKR may be more effective prior to the development of significant knee pain. After the onset of knee pain however, low impact or non-weight bearing activity should be considered to avoid worsening knee symptoms. For any figures or tables, please contact authors directly

Obesity is associated with worse outcomes following total knee/hip arthroplasty (TKA/TKA). This study aimed to determine the feasibility of a dietitian-led low-inflammatory weight-loss program for people with obesity awaiting arthroplasty. Quasi-experimental pilot study enrolled people with obesity waitlisted for primary TKA/THA into ‘usual care’ (UC) or weight-loss (low-inflammatory diet) program (Diet). Recruitment occurred between July 2019 and February 2020 at Fairfield and Campbelltown Hospitals. Assessments at baseline, pre-surgery, time of surgery and 90-days following surgery included anthropometric measurements, patient-reported outcomes, serum biomarkers and 90-day postoperative complication rate. 97 people consented to the study (UC, n=47, mean age 67, BMI 37, TKA 79%; Diet, n=50, mean age 66, BMI 36, TKA 72%). Baseline characteristics indicated gross joint impairments and poor compliance with a low-inflammatory diet. Study feasibility criteria included recruitment rate (52%), proportion of diet patients that improved compliance to low-inflammatory diet by ≥10% (57%) and had ≥60% attendance of dietitian consultations (72%), proportion of patients who undertook serum biomarkers (55%). By presurgery assessments, the diet group had more patients who cancelled their surgery due to symptom improvement (4 vs 0), reduced waist-circumference measurements, increased compliance with the Low-Inflammatory diet and preservation of physical activity parameters. More usual care participants experienced at least one postoperative complication to 90-days (59% vs 47%) and were discharged to inpatient rehabilitation (21% vs 11%). There was no difference in weight change, physical function, and patient-reported outcome measures from pre-surgery to 90-days post-surgery, and length of hospital stay. Using pre-determined feasibility criteria, conducting a definitive trial is not feasible. However, intervention audit demonstrated high intervention fidelity. Pilot data suggest our program may promote weight loss but the clinical effects for most are modest. Further research utilising a stronger intervention may be required to assess the effectiveness of a pre-arthroplasty weight-loss intervention

Introduction. We demonstrate the preliminary results with a novel technique to solve large bone defects using two lengthening nails, working together and aligned in a custom made device. An illustrative case that successfully produced 17 cm bone in 3.5 months, is presented. Materials and Methods. A 28 year old healthy male presented with a slowly growing mass in the left femur. No general symptoms were reported, no weight loss, no previous illness. Histopathology, CT and MRI scans revealed a malignant diaphyseal bone tumor. A three-stage trifocal bone transport was projected and conducted based on a 3D model test. Results. Trifocal bone transport using two lengthening nails in a custom made device, reduced the 17 cm bone defect in 3.5 months. Follow up was 9 months. Conclusions. The presented technique successfully solved the clinical problem and is a showcase for further developments of internal devices for complex and large bone losses and lengthenings

In a recent study, 54.5% of patients reporting to arthroplasty clinics in the US were obese. We performed a recent literature review to determine how obesity impacts outcomes in total hip and knee arthroplasty and what must be done to improve outcomes in the obese arthroplasty patient. Specifically, obese patients have shown increased rates of infection, dislocation, need for revision, wound dehiscence, increased operative time and prolonged hospital stay. Additionally, obese TKA patients have been shown to have increased rates of aseptic loosening, thromboembolic events, wound complications, and cardiopulmonary events. Worsening severity of obesity seems to correlate with worsening outcomes and super obesity (BMI>50) has been identified as an independent risk factor for complications. Patients with BMI>35 have shown to be 6.7 times more likely to develop infection after TKA. Patients with BMI>40 have a 3.35 times higher rate of revision for deep infection than those with BMI<35. The odds ratio for major complications increases dramatically beyond BMI>45. How can we improve outcomes in the obese patient? Preoperative care for the obese patient involves nutritional counseling, incorporating weight loss methods, physical therapy, metabolic workup and diagnosis and management of frequent comorbid conditions (OSA, DM2, HTN, HLD, malnutrition, renal failure). Identifying and managing comorbidities is especially important given that some comorbidities such as malnutrition have been shown to be as strong or even stronger an independent risk factor for postoperative TJA complications than obesity. In some cases higher complications were seen which some authors attribute to bariatric patients remaining in a catabolic state after weight loss.  . We know that obesity and its associated comorbid conditions do have worse outcomes and increased complications in TJA patients. We also know that complications proportionately increase with increasing severity of obesity. The super-obese population is at the greatest risk of complication following TJA and preoperative screening and management is essential in reducing complications. Although weight loss is important, bariatric data has shown that it does not solve the problem of obesity in itself and the patient's metabolic state is likely a more important issue. Implant selection is important and strong consideration should be given to avoiding direct anterior approach in the THA obese patient. Understanding of obesity specific complications and treatment options is crucial for patient counseling and optimization to ensure successful treatment in obese TJA patients

To describe the longitudinal trends in patients with obesity and Metabolic Syndrome (MetS) undergoing TKA and the associated impact on complications and lengths of hospital stay. We identified patients who underwent primary TKA between 2006 – 2017 within the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database. We recorded patient demographics, length of stay (LOS), and 30-day major and minor complications. We labelled those with an obese Body Mass Index (BMI ≥ 30), hypertension, and diabetes as having MetS. We evaluated mean BMI, LOS, and 30-day complication rates in all patients, obese patients, and those with MetS from 2006-2017. We used multivariable regression to evaluate the trends in BMI, complications, and LOS over time in all patients and those with MetS, and the effect of BMI and MetS on complication rates and LOS, stratified by year. 270,846 patients underwent primary TKA at hospitals participating in the NSQIP database. 63.71% of patients were obese (n = 172,333), 15.21% were morbidly obese (n = 41,130), and 12.37% met criteria for MetS (n = 33,470). Mean BMI in TKA patients increased at a rate of 0.03 per year (0.02-0.05; p < 0 .0001). Despite this, the rate of adverse events in obese patients decreased: major complications by an odds ratio (OR) of 0.94 (0.93-0.96; p < 0 .0001) and minor complications by 0.94 (0.93-0.95; p < 0 .001). LOS also decreased over time at an average rate of −0.058 days per year (-0.059 to −0.057; p < 0 .0001). The proportion of patients with MetS did not increase, however similar improvements in major complications (OR 0.94 [0.91-0.97] p < 0 .0001), minor complications (OR 0.97 [0.94-1.00]; p < 0 .0330), and LOS (mean −0.055 [-0.056 to −0.054] p < 0 .0001) were found. In morbidly obese patients (BMI ≥ 40), there was a decreased proportion per year (OR 0.989 [0.98-0.994] p < 0 .0001). Factors specifically associated with major complications in obese patients included COPD (OR 1.75 [1.55-2.00] p < 0.0001) and diabetes (OR 1.10 [1.02-1.1] p = 0.017). Hypertension (OR 1.12 [1.03-1.21] p = 0.0079) was associated with minor complications. Similarly, in patients with MetS, major complications were associated with COPD (OR 1.72 [1.35-2.18] p < 0.0001). Neuraxial anesthesia was associated with a lower risk for major complications in the obese cohort (OR 0.87 [0.81-0.92] p < 0.0001). BMI ≥ 40 was associated with a greater risk for minor complications (OR 1.37 [1.26-1.50] p < 0.0001), major complications (1.11 [1.02-1.21] p = 0.015), and increased LOS (+0.08 days [0.07-0.09] p < 0.0001). Mean BMI in patients undergoing primary TKA increased from 2006 - 2017. MetS comorbidities such as diabetes and hypertension elevated the risk for complications in obese patients. COPD contributed to higher rates of major complications. The obesity-specific risk reduction with spinal anesthesia suggests an improved post-anesthetic clinical course in obese patients with pre-existing pulmonary pathology. Encouragingly, the overall rates of complications and LOS in patients with obesity and MetS exhibited a longitudinal decline. This finding may be related to the decreased proportion of patients with BMI ≥ 40 treated over the same period, possibly the result of quality improvement initiatives aimed at delaying high-risk surgery in morbidly obese patients until healthy weight loss is achieved. These findings may also reflect increased awareness and improved management of these patients and their elevated risk profiles

The prevalence of Class III Obesity (BMI ≥ 40 kg/m25) in black women is 18%, three times the 6 national average. Class III obesity is associated with mobility limitations, particularly hip joint 7 deterioration. Therefore black women are highly likely to come to the attention of orthopedic 8 surgeons. Weight loss associated with bariatric surgery should lead to enhanced success of hip 9 replacements. However, we present a case of a black woman who underwent Roux-en-y gastric 10 bypass with the expectation that weight loss would improve her ambulation and if necessary 11 make her a better surgical candidate for hip replacement. Her gastric bypass was successful as her BMI declined from 52.0 kg/m2 to 33.7 kg/m212. However, her hip circumference post weight 13 loss remained persistently high. As a consequence, the soft tissue tunnel geometry presented 14 major challenges. The tunnel depth as well as the immobility of the soft tissue envelope 15 interfered with retractor placement, tissue reflection and adequate surgical access to the 16 acetabulum. Therefore a traditional cup placement could not be achieved. Instead, a 17 hemiarthroplasty was performed. Her pre-surgery Harris Hip Score was 17.0. In the first few 18 months post surgery there were improvements, specifically a decrease in pain and a decreased 19 reliance on external support. But her overall functional independence never improved. This case 20 is presented to raise awareness that improved BMI category post bariatric surgery is not 21 sufficient to guarantee that orthopedic risks have been minimized. Overall, weight loss does 22 improve both the metabolic profile and anesthesia risk, but the success rate of total hip 23 arthroplasties will be low if fat mass (i.e. high hip circumference) in the operative field remains 24 high. We are now repeatedly recognizing this problem but are not finding any case reports on 25 this issue. Therefore we provide a practical approach to evaluate these patients and describe 26 ways we have found to successfully address intra-operative challenges

Direct metal printed (DMP) porous iron implants possess promising mechanical and corrosion properties for various clinical application. Nevertheless, there is a requirement for better co-relation between in vitro and in vivo corrosion and biocompatibility behaviour of such biomaterials. Our present study evaluates absorption of porous iron implants under both static and dynamic conditions. Furthermore, this study characterizes their cytocompatibility using fibroblastic, osteogenic, endothelial and macrophagic cell types. In vitro degradation was performed statically and dynamically in a custom-built set-up placed under cell culture conditions (37 °C, 5% CO2 and 20% O2) for 28 days. The morphology and composition of the degradation products were analysed by scanning electron microscopy (SEM, JSM-IT100, JEOL). Iron implants before and after immersion were imaged by μCT (Quantum FX, Perkin Elmer, USA). Biocompatibility was also evaluated under static and dynamic in vitro culture conditions using L929, MG-63, HUVEC and RAW 264.7 cell lines. According to ISO 10993, cytocompatibility was evaluated directly using live/dead staining (Live and Dead Cell Assay kit, Abcam) in dual channel fluorescent optical imaging (FOI) and additionally quantified by flow cytometry. Furthermore, cytotoxicity was indirectly quantified using ISO conform extracts in proliferation assays. Strut size of DMP porous iron implants was 420 microns, with a porosity of 64% ± 0.2% as measured by micro-CT. After 28 days of physiological degradation in vitro, dynamically tested samples were covered with brownish degradation products. They revealed a 5.7- fold higher weight loss than statically tested samples, without significant changes in medium pH. Mechanical properties (E = 1600–1800 MPa) of these additively manufactured implants were still within the range of the values reported for trabecular bone, even after 28 days of biodegradation. Less than 25% cytotoxicity at 85% of the investigated time points was measured with L929 cells, while MG-63 and HUVEC cells showed 75% and 60% viability, respectively, after 24 h, with a decreasing trend with longer incubations. Cytotoxicity was analysed by two-way ANOVA and post-hoc Tukey's multiple comparisons test. Under dynamic culture conditions, live-dead staining and flow cytometric quantification showed a 2.8-fold and 5.7-fold increase in L929 and MG-63 cell survival rates, respectively, as compared to static conditions. Therefore, rationally designed and properly coated iron-based implants hold potential as a new generation of absorbable Orthopaedic implants

Bioabsorbable metals hold a lot of potential as orthopaedic implant materials. Three metal families are currently being investigated: iron (Fe), magnesium (Mg) and zinc (Zn). Currently, however, biodegradation of such implants is poorly predictable. We thus used Direct Metal Printing to additively manufacture porous implants of a standardized bone-mimetic design and evaluated their mechanical properties and degradation behaviour, respectively, under in vivo-like conditions. Atomized powder was manufactured to porous implants of repetitive diamond unit cells, using a ProX DMP 320 (Layerwise, Belgium) or a custom-modified ReaLizer SLM50 metal printer. Degradation behaviour was characterized under static and dynamic conditions in a custom-built bioreactor system (37ºC, 5% CO. 2. and 20% O. 2. ) for up of 28 days. Implants were characterized by micro-CT before and after in vivo-like degradation. Mechanical characterization (according to ISO 13314: 2011) was performed on an Instron machine (10kN load cell) at different immersion times in simulated body fluid (r-SBF). Morphology and composition of degradation products were analysed (SEM, JSM-IT100, JEOL). Topographically identical titanium (Ti-6Al-4V, Ti64) specimen served as reference. Micro-CT analyses confirmed average strut sizes (420 ± 4 μm), and porosity (64%), to be close to design values. After 28 days of in vivo-like degradation, scaffolds were macroscopically covered by degradation products in an alloy-specific manner. Weight loss after cleaning also varied alloy-specifically, as did the change in pH value of the r-SBF. Corrosion time-dependent changes in Young's moduli from 1200 to 800 MPa for Mg, 1000 to 700 MPa for Zn and 48-8 MPa for iron were statistically significant. In summary, DMP allows to accurately control interconnectivity and topology of implants from all three families and micro-structured design holds potential to optimize their degradation speed. This first systematic report sheds light into how design influences degradation behaviour under in vivo-like conditions to help developing new standards for future medical device evaluation

Obesity is a leading public health concern and it is increasing in prevalence over the last 20 years. Obesity prevalence has doubled in adults and tripled in adolescents. The United States is the leading country in terms of percent obesity. Most alarming is the fact that the fastest growing rates of obesity are in the highest BMI groups. The issue of obesity is a particular concern to arthroplasty surgeons since there is an association between the increasing incidence of obesity and the increasing rate of joint replacement. Also of concern is that obese patients tend to be younger and complication rates and revision rates are higher in young patients which is only compounded by the presence of obesity. The risk of virtually every major complication is substantially higher in obese patients. Of concern, however, is a recent study indicating that bariatric surgery with successful weight loss does not necessarily decrease the complication rate. Obesity is also associated with substantially higher costs. There is some evidence that obesity doesn't necessarily affect implant survival. There is also evidence that the clinical outcomes may not be substantially compromised by the presence of obesity. Based on data from studies such as this, some centers have stated that it is difficult to justify withholding surgery based on BMI alone. The data on weight loss following surgery indicates the vast majority of patients did not lose weight following joint replacement. In one study a higher proportion of patients gained weight than lost weight

Early detection of knee osteoarthritis (OA) is critical for possible preventive treatment, such as weight loss, physical activity and sports advice and restoring biomechanics, to postpone total knee arthroplasty (TKA). Specific biomarkers for prognosis and early diagnosis of OA are lacking. Therefore, in this study, we analyzed the lipid profiles of different tissue types within Hoffa's fat pad (HFP) of OA and cartilage defect (CD) patients, using matrix-assisted laser desorption ionization (MALDI) mass spectrometry imaging (MSI). The HFP has already been shown to play an important role in the inflammatory process in OA by prostaglandin release. Additionally, MALDI-MSI allows us to investigate on tissue lipid distribution at molecular level, which makes it a promising tool for the detection of disease specific biomarkers for OA development. Samples of HFP were obtained of patients undergoing surgical treatment for OA (n=3) (TKA) or CD (n=3) (cartilage repair). In all cases, tissue was obtained without patient harm. HFP samples were washed in phosphate buffered saline (PBS) and snap-frozen directly after surgical dissection to remove redundant blood contamination and to prevent as much tissue degradation as possible. Tissue sections were cut at 15 µm thickness in a cryostat (Leica Microsystems, Wetzlar) and deposited on indium tin oxide glass slides. Norharmane (Sigma-Aldrich) matrix was sublimed onto the tissue using the HTX Sublimator (HTX Technologies, Chapel Hill). µMALDI-MSI was performed using Synapt G2Si (Waters) at 50 µm resolution in positive ion mode. MS/MS fragmentation was performed for lipid identification. Data were processed with in-house Tricks for MATLAB and analyzed using principle component analysis (PCA) and verlan. OA and CD HFP specific lipid profiles were revealed by MALDI-MSI followed by PCA and DA. With these analyses we were able to distinguish different tissue types within HFP of different patient groups. Further discriminant analysis showed HFP intra-tissue heterogeneity with characteristic lipid profiles specific for connective and adipose tissues, but also for synovial tissue and blood vessels, revealing the high molecular complexity of this tissue. As expected, lipid signals were lower at the site of the connective tissue, compared to the adipose tissue. In particular, tri-acyl glycerol, di-acyl glycerol, sphingomyelin and phosphocholine species were differently abundant in the adipose tissue of HFP of OA compared to CD. To our knowledge, this is the first study comparing lipid profiles in HFP of OA patients with CD patients using MALDI-MSI. Our results show different lipid profiles between OA and CD patients, as well as intra-tissue heterogeneity within HFP, rendering MALDI-MSI as a useful technology for OA biomarker discovery. Future research will focus on expanding the number of subjects and the improvement of lipid detection signals

An increase in metal ion levels is seen after implantation of all MoM hip prosthesis due to release from the surface directly, more so during articulation and corrosion of the bearing surfaces. The bearing surfaces in MoM prosthesis consist of cobalt, chromium and molybdenum. Several case-reports of cobalt toxicity due to a MoM prosthesis have been published in the last decade. Cobalt intoxication may lead to a variety of symptoms: neuro-ocular toxicity (tinnitus, vertigo, deafness, blindness, convulsions, headaches and peripheral neuropathy), cardiotoxicity and thyroid toxicity. Nausea, anorexia and unexplained weight loss have been described. Systemic effects from metal ions even with well functioning implants or with ion concentrations lower than those associated with known adverse effects may exist and warrant investigation. The aim of this study is to investigate self-reported systemic complaints in association with cobalt ion concentrations in patients with any type of MoM hip prosthesis. A cohort study was conducted. Patients with both unilateral and bilateral, resurfacing and large head metal on metal total hip arthroplasties were included for the current study. Blood metal ion concentrations (cobalt and chromium) were measured by inductively coupled plasma mass spectrometry (ICP-MS). Based on the known cobalt toxicity symptoms of case-reports and toxicology reports a new non-validated questionnaire was developed. questions were subdivided in general questions/symptoms, vestibular symptoms, neurological symptoms, emotional health and cardio- and thyroid toxicity symptoms. Independent samples T test, Fishers Exact Test and Pearsons (R) correlation were used. Analysis was performed on two groups; a low cobalt ion concentration group and a high cobalt ion concentration group A total of 62 patients, 36 (58%) men and 26 (42%) women, were included with a mean age at surgery of 60.8 ± 9.3 years (41.6 – 78.1) and a mean follow up of 6.3 ± 1.4years (3.7 – 9.6). In these patients a total of 71 prosthesis were implanted: 53 unilateral and 9 bilateral. Of these, 44 were resurfacing and 27 large head metal on metal (LHMoM) total hip arthroplasties. Mean cobalt and chromium ion concentrations were 104 ± 141 nmol/L (9 – 833) and 95 ± 130nmol/L (6 – 592), respectively. Based on the different thresholds (120 – 170 or 220 nmol/L) the low cobalt ion concentration group consisted of 44 (71%), 51 (82%) or 55 (89%) subjects respectively. No differences were found in general characteristics, independently of the threshold. The composite score of vestibular symptoms (vision, hearing, tinnitus, dizziness) was significantly higher (p < .050) in all high cobalt ion concentrations groups, independent of the threshold value This study aimed to detect a trend in self-reported systemic complaints in patients with metal-on-metal hip arthroplasty due to raised cobalt ion concentrations. Vestibular symptoms were more common in high cobalt ion concentration groups independent of the three threshold levels tested. The upper limit of acceptable cobalt ion concentrations remains uncertain. With regards to proactively inquired, self-reported symptoms the threshold where effects may be present could be lower than values currently applied in clinical follow-up. It is unknown what exposure to elevated metal ion concentrations for a longer period of time causes with aging subjects. Further research with a larger cohort and a more standardized questionnaire is necessary to detect previously undiscovered or under-reported effects

Weight loss is commonly recommended as a treatment for back pain. However, there is little literature to support this. A recent systematic review has identified only studies relating to bariatric surgery. There are no other studies that address whether weight loss improves back pain. Forty-five consecutive consenting patients were recruited following enrolment in a tertiary multidisciplinary weight management program. These patients were referred primarily for treatment of obesity. The program consisted of consultation and on-going supervision by a sub-specialty weight management physician, and group and individual sessions addressing diet, exercise and behaviour modification. Patients were assessed by independent observers prior to start of program and at twelve weeks into the program with standardised and validated outcomes tools measuring baseline factors, back pain and related functional disability at twelve weeks follow-up. Prior to starting the program, forty-two patients (93%) reported some degree of low back pain of which 40% rated their pain as moderate (n = 12) or severe (n = 6). Using the Oswestry Low Back Pain Disability Index, 73% patients reported moderate (n = 18) or severe disability (n = 15). At twelve weeks, thirty-seven (82%) patients were available for assessment. There were significant improvement in VAS pain scores (mean change = 1.5, 95% CI: 0.7 to 2.4) and in Oswestry Low Back Disability Index (mean change= 8.6, 95% CI: 3.9 to 13.2). There were significant reductions in the prevalence of moderate or severe back pain (p = 0.04) and moderate or severe disability (p = 0.007) in the entire group. This is the first study to provide empirical evidence on the positive effects of a weight loss program on back pain. These results lay the groundwork for longer follow-up and comparative studies

Introduction: The accepted method of assessing wear following a hip simulator test has been to use a precision balance. As the MoM devices produce significantly less weight loss than hard-on-soft bearings, the measurements of MoM devices are now almost at the detection limit of many balances. There is a need for a method that can be used in conjunction with gravimetric analysis that will provide an accurate assessment of ion concentration levels that will support the gravimetric measurements. Aim: To develop a method to assess wear using metal ion analysis in order to support gravimetric measurements of metal on metal devices. Materials and methods: Hip simulator test: Three pairs of 50 mm diameter as cast CoCr MoM devices were tested in a ProSim hip wear simulator (SimSol Stockport/UK) under physiologically relevant conditions. The lubricant was new born calf serum with 0.2 % sodium azide concentration diluted with de-ionised water for protein concentration of 20 g/l. Stop-start motion was implemented every 100 cycles. Lubricant changed every 125 k cycles. The frequency was 0.5 Hz. Wear was assessed gravimetrically at every 0.5 million cycles (Mc) interval. Ion analysis: Serum was collected from test station and allowed to settle for 12 hours. An aliquot of 20 ml from lubricant was collected. Each sample was centrifuged at 2500 g-force for 10 minutes. A 10 ml aliquot was collected from each sample and was further centrifuged at 2500 g-force for 10 minutes. 1.5 ml aliquot was collected and stored at −20 °C. A high resolution inductively-coupled plasma mass spectrometry instrument (ELEMENT, ThermoFinnigan MAT, Bremen/Germany) was then used for the analysis of metal ions. Results and Discussion: The average cumulative metal ion levels at 0.5, 1 and 1.5 Mc showed similar trends in wear to that of the average cumulative weight loss assessed gravimetrically. There were similar biphasic wear trends in both metal ion levels and gravimetric weight losses. Other studies have also shown similar correlation between volume loss and ion concentration levels. The percentage distribution of Co, Cr and Mo in the metal ion samples are in close agreement with nominal chemical composition of the material tested. Conclusion: This study showed that metal ion measurements can help to confirm gravimetrically measured material loss

The April 2015 Foot & Ankle Roundup. 360 . looks at: Plantar pressures linked to radiographs; Strength training for ankle instability?; Is weight loss good for your feet?; Diabetes and foot surgery complications; Tantalum for failed ankle arthroplasty?; Steroids, costs and Morton’s neuroma; Ankle arthritis and subtalar joint