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

Introduction. The identification of biological markers associated to implant failure in THA (total hip arthroplasty) patients remains a challenge in orthopedic surgery. In this search, previous studies have been mainly focused on typical mediators associated to bone metabolism and inflammation. Our group has evaluated changes in serum levels of insulin-like growth factor binding protein-1 (IGFBP-1), a protein which is not directly related to bone homeostasis, in patients undergoing THA. Method. We assessed IGFBP-1 levels in serum obtained from 131 patients (58% female, 42 % male; age: 68 ± 13 years) who underwent THA in the Orthopedic Surgery and Traumatology Department of our institution. In this cohort, 57% of patients had metal on polyethylene (MoP) as hip-bearing surface combination, 17 % had ceramic on ceramic (CoC) and 26% of them did not have any prosthesis. A test based on an enzyme-linked immunosorbent assay (ELISA) was used to determine IGFBP-1 levels in serum obtained from these patients. Result. Our results showed a significant increase in IGFBP- 1 levels in MoP group as compared to CoC and control groups, in which no differences in quantified levels were detected. Further analysis revealed no significant differences in IGFBP-1 between cemented and non-cemented MoP bearings. We performed a ROC curve to evaluate the accuracy of serum IGFBP-1 in discriminating MoP from the rest of patients (area under the curve: 0.7; 95% confidence interval: 0,6-0.8; p<0.05) and established a cut-off value of 10.2 ng/ml, according to the Youden´s Index. Logistic regression analysis showed that patients with MoP bearing surfaces had a higher risk of increased IGFBP- 1 levels in serum (p<0.05, Odds Ratio: 6.7, 95% Confidence Interval 3.1 to 14.8). Conclusion. IGFBP- 1 levels are significantly elevated in THA patients with MoP bearing surfaces, suggesting that this protein might be a reliable biomarker for the outcome of patients implanted with MoP

Introduction and Objective. Continuous peripheral nerve blocks (cPNBs) have shown good results in pain management after orthopedic surgeries. However, the variation of performance between different subspecialities is unknown. The aim of this study is to describe our experience with cPNBs after lower limb orthopedic surgeries in different subspecialties. Materials and Methods. This prospective cohort study was performed on collected data from cPNBs after orthopedic surgeries in lower limbs. Catheters were placed by experienced anesthesiologists using sterile technique. After catheterization, the patients were examined daily, by specially educated acute pain service nurses. The characteristics of the patients, duration of catheterization, severity of the post-operative pain, need for additional opioids, and possible complications were registered. Results. We included 246 patients (=547 catheters). 115 (21%) femoral, 162 (30%) saphenous, 66 (12%) sciatic, and 204 (37%) popliteal sciatic nerve catheter were used. The median duration of a catheter was 3 days [IQR = 2 – 5]. The proportion of femoral, sciatic, saphenous, and popliteal nerve catheters with duration of more than two days was 81%, 79%, 73%, and 71% for, respectively. This proportion varied also between different subspecialties. 91% of the catheters remained in place for more than two days in amputations (n=56), 89% in pediatric surgery (n=79), 76% in trauma (n=217), 64% in foot and ankle surgery (n=129), and 59% in limb reconstructive surgery (n=66). The proportion of pain-free patients were 77 – 95% at rest, 63 – 88% at mobilization. 79 – 92% did not need increased opioid doses, and 50 – 67% did not require PRN opioid. 443 catheters (81%) were removed as planned. The cause of unplanned catheter removal was loss of efficacy in 69 (13%), dislodgement in 23 (4.2%), leakage in 8 (1.5%), and erythema in 4 catheters (0.73%). No major complication occurred. Conclusions. 81% of catheters remained in place until planned removal and opioid usage after surgery was lower than expected. Catheters were efficient in both adult and pediatric surgery; however, a variation was seen between orthopaedic subspecialities regarding duration of nerve catheter usage

To date, few studies have investigated the feasibility of the loop-mediated isothermal amplification (LAMP) assay for identifying pathogens in tissue samples. This study aimed to investigate the feasibility of LAMP for the rapid detection of methicillin-susceptible or methicillin-resistant Staphylococcus aureus (MSSA or MRSA) in tissue samples, using a bead-beating DNA extraction method. Twenty tissue samples infected with either MSSA (n = 10) or MRSA (n = 10) were obtained from patients who underwent orthopedic surgery for suspected musculoskeletal infection between December 2019 and September 2020. DNA was extracted from the infected tissue samples using the bead-beating method. A multiplex LAMP assay was conducted to identify MSSA and MRSA infections. To recognize the Staphylococcus genus, S. aureus, and methicillin resistance, 3 sets of 6 primers for the 16S ribosomal ribonucleic acid (rRNA) and the femA and mecA genes were used, respectively. The limit of detection and sensitivity (detection rate) of the LAMP assay for diagnosing MSSA and MRSA infection were analyzed. The results of this study suggest that the LAMP assay performed with tissue DNA samples can be a useful diagnostic method for the rapid detection of musculoskeletal infections caused by MSSA and MRSA

Smartphones are often equipped with inertial sensors capable of measuring individuals' physical activities. Their role in monitoring the patients' physical activities in telemedicine, however, needs to be explored. The main objective of this study was to explore the correlation between a participant's daily step counts and the daily step counts reported by their smartphone. This prospective observational study was conducted on patients undergoing lower limb orthopedic surgery and a group of non-patients. The data collection period was from 2 weeks before until four weeks after the surgery for the patients and two weeks for the non-patients. The participants' daily steps were recorded by physical activity trackers employed 24/7, and an application recorded the number of daily steps registered by the participants' smartphones. We compared the cross-correlation between the daily steps time-series taken from the smartphones and physical activity trackers in different groups of participants. We also employed mixed modeling to estimate the total number of steps. Overall, 1067 days of data were collected from 21 patients (11 females) and 10 non-patients (6 females). The cross-correlation coefficient between the smartphone and physical activity tracker was 0.70 [0.53–0.83]. The correlation in the non-patients was slightly higher than in the patients (0.74 [0.60–0.90] and 0.69 [0.52–0.81], respectively). Considering the ubiquity, convenience, and practicality of smartphones, the high correlation between the smartphones and the total daily step time-series highlights the potential usefulness of smartphones in detecting the change in the step counts in remote monitoring of the patient's physical activity

The Royal College of Surgeons of England (RCS) Good Surgical Practice guidance identifies essential criteria for surgical operation note documentation. The current quality improvement project aims to identify if using pre-templated operation notes for documenting fractured neck of femur surgery results in improved documentation when compared to free hand orthopaedic operation notes. A total of fourteen categories were identified from the RCS guidance as required across all the operations identified in this study. All operations for the month of October 2021 were identified and the operation notes analysed. Pre-templated operation notes were compared to free hand operation notes. 97 cases were identified, of which 74 were free hand operation notes and 23 were pre-templated fractured neck of femur operation notes. All fourteen categories were completed in 13 (57%) of the templated operation notes vs 0 (0%) in the free hand operation notes (odds ratio 0.0052, 95% CI 0.0003 to 0.0945, p < 0.001). The median total number of completed categories was significantly higher in the templated op-note group compared to the free hand op-note group (templated median 14, range 12-14, vs. free hand median 11, range 9 to 13, p < 0.001). Logistic regression analysis of operation notes written by Registrars or Consultants identified Registrars as more likely to document the antibiotic prophylaxis given (p = 0.025). Use of pre-templated operation notes results in significantly improved documentation. Adoption of generic pre-templated operation notes to improve surgical documentation should be considered across all operations

Introduction. Postvoid residualurine (PVR) can be an unknown chronic disorder, but it can also occur after surgery. A pilot-study initiated in Elective Surgery Center, Silkeborg led to collaboration with a urologist to develop a flowchart regarding treatment of PVR. Depending on the severity, men with significant PVR volumes were either recommend follow up by general practitioner or referred to an urologist for further diagnose and/or treatment. Aim: to determine the prevalence of pre- and postoperative PVR in men >65 years undergoing orthopedic surgeries and associated risk factors. Method. A single-center, prospective cohort study. Male patients were consecutively included during one year from April 2022. Data was extracted from the electronic patient files: age, lower urinary tract symptoms (LUTS), co-morbidity (e.g. diabetes), type of surgery and anesthesia, opioid use, pre- and postoperative PVR. Result. 796 participants; 316 knee-, 276 hip-, 26 shoulder arthroplasties and 178 lower back spinal surgeries. 95% (755) were bladder scanned preoperatively. 12% (89) had PVR 150-300ml, and 3% (23) had PVR >300ml. There was a higher risk of preoperative PVR ≥150ml in patients reporting LUTS, OR 1.97(1.28;3.03), having known neurological disease, OR 3.09(1.41;6.74), and the risk increased with higher age, OR 1.08 per year (1.04;1.12). Diabetes and the type of surgery was not associated with higher risk of PVR. 72% (569) had a postoperative bladder scan. 15% (95%CI: 12-19%) (70) patients without PVR preoperatively had PVR ≥150ml postoperatively. Conclusion. Approximately 15% of the men had PVR ≥150ml preoperatively. Neurological disease was the most severe risk factor and secondary if reporting LUTS. As expected, the risk increased with age. Neither diabetes nor the type of surgery was associated with higher risk. 15% of men without preoperative PVR had PVR after surgery. It is not possible to conclude if it is transient or chronic but further studies are ongoing

In the last years, 3d printing has progressively grown and it has reached a solid role in clinical practice. The main applications brought by 3d printing in orthopedic surgery are: preoperative planning, custom-made surgical guides, custom-made im- plants, surgical simulation, and bioprinting. The replica of the patient's anatomy, starting from the elaboration of medical volumetric images (CT, MRI, etc.), allows a progressive extremization of treatment personalization that could be tailored for every single patient. In complex cases, the generation of a 3d model of the patient's anatomy allows the surgeons to better understand the case — they can almost “touch the anatomy” —, to perform a more ac- curate preoperative planning and, in some cases, to perform device positioning before going to the surgical room (i.e. joint arthroplasty). 3d printing is also commonly used to produce surgical cutting guides, these guides are positioned intraoperatively on given landmarks to guide the surgeon to perform a specific surgical act (bone osteotomy, bone resection, implant position, etc.). In total knee arthroplasty, custom-made cutting guides have been developed to help the surgeon align the femoral and tibial components to the pre-arthritic condition with- out the use of the intramedullary femoral guide. 3d printed custom-made implants represent an emerging alternative to biological reconstructions especially after oncologic resection surgery or in case of complex arthroplasty revision surgery. Custom-made implants are designed to re- place the original shape and size of the patient's bone and they allow an extreme personalization of the treatment for every single patient. Patient-specific surgical simulation is a new frontier that promises great benefits for surgical training. a solid 3d model of the patient's anatomy can faithfully reproduce the surgical complexity of the patient and it allows to generate surgical simulators with increasing difficulty to adapt the difficulties of the course with the level of the trainees performing structured training paths: from the “simple” case to the “complex” case

In orthopedic surgery, implant infections are a serious issue and difficult to treat. The aim of this study was to use superparamagnetic nanoporous silica nanoparticles (MNPSNP) as candidates for directed drug delivery. Currently, short blood circulation half-life due to interactions with the host's immune system hinder nanoparticles in general from being clinically used. PEGylation is an approach to reduce these interactions and to enhance blood circulation time. The effect of PEGylation of the used . 68. Ga-labelled MNPSNP on the distribution and implant accumulation was examined by PET/CT imaging and gamma counting in an implant mouse model. Female Balb/c mice (n=24) received a magnetic implant subcutaneously on the left and a titanium implant on the right hind leg. On day one, 12 of these mice received an additional clodronate®-injection for macrophage depletion. On the second postoperative day, mice were anaesthetized and MNPSNP (native or PEGylated) injected intravenously, followed by a dynamic PET-scan over 60 minutes, a CT- and a static PET-scan at 120 min. As control, 12 mice received only . 68. Ga-MNPSNP (native or PEGylated). Gamma counting of inner organs, urine, blood and implant area was performed as further final analysis. Although PEGylation of the nanoparticles already resulted in lower liver uptakes, both variants of . 68. Ga-labeled MNPSNP accumulated in liver and spleen. Combination of PEGylation with clodronate®-injection led to a highly significant effect whereas clodronate®-injection alone could not reveal significant differences. In gamma counting, a significantly higher %I.D./g was found for the tissue surrounding the magnetic implants compared to the titanium control, although in a low range. PEGylation and/or clodronate®-injection revealed no significant differences regarding nanoparticle accumulation at the implantation site. PEGylation increases circulation time, but MNPSNP accumulation at the implant site was still insufficient for treatment of infections. Additional efforts have to further increase circulation time and local accumulation. Acknowledgements: This work is funded by the German Research Foundation (DFG, project number 280642759)

Introduction. The concept of same-day discharge has garnered increasing significance within orthopedic surgery, particularly in hip and knee procedures. Despite initial concerns surrounding the absence of prolonged hospital care, a burgeoning body of evidence highlights numerous advantages associated with same-day discharge, ranging from mitigating in-hospital infections to offering substantial financial and psychosocial benefits for both patients and healthcare providers. In this study, we aim to scrutinize the trends in same-day discharge specifically within the realm of total hip arthroplasties. Method. This retrospective analysis delves into the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database spanning from 2017 to 2021. Leveraging patient data sourced from the ACS NSQIP database, we sought to elucidate patterns and shifts in same-day discharge practices pertaining to total hip arthroplasties. Result. The preoperative analysis illuminated several notable disparities between patients undergoing same-day hip arthroplasty and those necessitating hospitalization. Notably, same-day hip patients skewed younger, comprising 48.3%females compared to 55.6% in hospitalized hip patients. Furthermore, a lower prevalence of medical comorbidities such as diabetes mellitus (8.5% vs.12.9%), current smoking (9.3% vs. 12.2%), and severe COPD(1.9% vs. 4.1%) was observed among same-day hip group. Operatively, same-day hip surgeries boasted shorter durations, averaging 83.9 minutes, in contrast to the 92.3minutes for hospitalized hip procedures. Postoperatively, same-day hip patients exhibited significantly diminished rates of 30-day readmissions (1.7%vs. 3.5%), procedure-related readmissions (1.0%vs.2.1%), reoperations (1.1%vs.1.9%), and mortality (0.02% vs. 0.04%). Moreover, the prevalence of the same-day discharge concept experienced a remarkable ascent from 2016 to 2021, with rates escalating from 1.5% to 25.6% of all total hip arthroplasties over a span of just six years. Conclusion. In conclusion, same-day discharge is a feasible and safe option for selected THA patients

Scoliosis correction surgery is one of the longest and most complex procedures of all orthopedic surgery. The complication rate is therefore not negligible and is particularly high when the surgery is performed in patients with neuromuscular or connective tissue disease or complex genetic syndromes. In fact, these patients have various comorbidities and organ deficits (respiratory capacity, swallowing / nutrition, heart function, etc.), which can compromise the outcome of the surgery. In these cases, an accurate assessment and preparation for surgery is essential, also making use of external consultants. To make this phase simpler, more effective and homogeneous, a multidisciplinary path of peri-operative optimization is being developed in our Institute, which also includes the possibility of post-operative hospitalization for rehabilitation and recovery. The goal is to improve the basic functional status as much as possible, in order to ensure faster functional recovery and minimize the incidence of peri-operative complications, to be assessed by clinical audit. The path model and the preliminary results on the first patients managed according to the new modality are presented here. The multidisciplinary path involves the execution of the following assessments / interventions: • Pediatric visit with particular attention to the state of the upper airways and the evaluation of chronic or frequent inflammatory states • Cardiological Consultation with Echocardiogram. • Respiratory Function Tests, Blood Gas Analysis and Pneumological Consultation to evaluate indications for preoperative respiratory physiotherapy cycles, Non-Invasive Ventilation (NIV) cycles, Cough Machine. Possible Polysomnography. • Nutrition consultancy to assess the need for nutritional preparation in order to improve muscle trophism. • Consultation of the speech therapist in cases of dysphagia for liquids and / or solids. • Electroencephalogram and Neurological Consultation in epileptic patients. • Physiological consultation in patients already being treated with a cough machine and / or NIV. • Availability of postoperative hospitalization in the rehabilitation center (with skills in respiratory and neurological rehabilitation) for the most complex cases. When all the appropriate assessments have been completed, the anesthetist in charge at our Institute examines the clinical documentation and establishes whether the path can be considered complete and whether the patient is ready for surgery. At the end of the surgery, the patient is admitted to the Post-operative Intensive Care Unit of the Institute. If necessary, a new program of postoperative rehabilitation (respiratory, neuromotor, etc.) is programmed in a specialist reference center. To date, two patients have been referred to the preoperative optimization path: one with Ullrich Congenital Muscular Dystrophy, and one with 6q25 Microdeletion Syndrome. In the first case, the surgery was performed successfully, and the patient was discharged at home. In the second case, after completing the optimization process, the surgery was postponed due to the finding of urethral malformation with the impossibility of bladder catheterization, which made it necessary to proceed with urological surgery first. The preliminary case series presented here is still very limited and does not allow evaluations on the impact of the program on the clinical practice and the complication rate. However, these first experiences made it possible to demonstrate the feasibility of this complex multidisciplinary path in which a network of specialists takes part

Tourniquet is widely used in orthopedic surgery to reduce intraoperative bleeding and improve visualization. We evaluated the effect of tourniquet application on both peri- and postoperative cefuroxime concentrations in subcutaneous tissue, skeletal muscle, calcaneal cancellous bone, and plasma. The primary endpoint was the time for which the free drug concentration of cefuroxime was maintained above the clinical breakpoint minimal inhibitory concentration (T>MIC) forStaphylococcus aureus (4 µg/mL). Ten patients scheduled for hallux valgus or hallux rigidus surgery were included. Microdialysis catheters were placed for sampling of cefuroxime concentrations bilaterally in subcutaneous tissue, skeletal muscle, and calcaneal cancellous bone. A tourniquet was applied on the thigh of the leg scheduled for surgery. Cefuroxime (1.5 g) was administered intravenously as a bolus 15 minutes prior to tourniquet inflation, followed by a second dose 6 hours later. The mean tourniquet duration (range) was 65 (58; 77) minutes. Dialysates and venous blood samples were collected for 12 hours. For cefuroxime the T>MIC (4 μg/mL) ranged between 4.8–5.4 hours across compartments, with similar results for the tourniquet and non-tourniquet leg. Comparable T>MIC and penetration ratios were found for the first and second dosing intervals. We concluded that administration of cefuroxime (1.5 g) 15 minutes prior to tourniquet inflation is safe in order to achieve tissue concentrations above 4 µg/mL throughout surgery. A tourniquet application time of approximately 1 hour did not affect the cefuroxime tissue penetration in the following dosing interval

With the increase in the elderly population, there is a dramatic increase in the number of spinal fusions. Spinal fusion is usually performed in cases of primary instability. However it is also performed to prevent iatrogenic instability created during surgical treatment of spinal stenosis in most cases. In literature, up to 75% of adjacent segment disease (ASD) can be seen according to the follow-up time. 1. Although ASD manifests itself with pathologies such as instability, foraminal stenosis, disc herniation or central stenosis. 1,2. There are several reports in the literature regarding lumbar percutaneous transforaminal endoscopic interventions for lumbar foraminal stenosis or disc herniations. However, to the best our knowledge, there is no report about the treatment of central stenosis in ASD. In this study, we aimed to investigate the short-term results of unilateral biportal endoscopic decompressive laminotomy (UBEDL) technique in ASD cases with symptomatic central or lateral recess stenosis. The number of patients participating in the prospective study was 8. The mean follow-up was 6.9 (ranged 6 to 11) months. The mean age of the patients was 68 (5m, 3F). The development of ASD time after fusion was 30.6 months(ranged 19 to 42). Mean fused segments were 3 (ranged 2 to 8). Preoperative instability was present in 2 of the patients which was proven by dynamic lumbar x-rays. Preoperative mean VAS-back score was 7.8, VAS Leg score was 5.6. The preoperative mean JOA (Japanese Orthopaedic Association) score was 11.25. At 6th month follow-up, the mean VAS back score of the patients was 1, and the VAS leg score was 0.5. This improvement was statistically significant (p = 0.11 and 0.016, respectively). The mean JOA score at the 6th month was 22.6 and it was also statistically significant comparing preoperative JOA score(p = 0.011). The preoperative mean dural sac area measured in MR was 0.50 cm2, and it was measured as 2.1 cm. 2. at po 6 months.(p = 0.012). There was no progress in any patient's instability during follow-up. In orthopedic surgery, when implant related problems develop in any region of body (pseudoarthrosis, infection, adjacent fracture, etc.), it is generally treated by using more implants in its final operation. This approach is also widely used in spinal surgery. 3. However, it carries more risk in terms of devoloping ASD, infection or another complications. In the literature, endoscopic procedures have almost always been used in the treatment of ventral pathologies which constitute only 10%. In ASD, disease devolops as characterized by wide facet joint arthrosis and hypertrophied ligamentum flavum in the cranial segment and it is mostly presented both lateral recess and santal stenosis symptoms (39%). In this study, we found that UBEDL provides successful results in the treatment of patients without no more muscle and ligament damage in ASD cases with spinal stenosis. One of the most important advantages of UBE is its ability to access both ventral and dorsal pathologies by minimally invasive endoscopic aproach. I think endoscopic decompression also plays an important role in the absence of additional instability at postoperatively in patients. UBE which has already been described in the literature given successful results in most of the spinal degenerative diseases besides it can also be used in the treatment of ASD. Studies with longer follow-up and higher patient numbers will provide more accurate results

Calcium phosphate ceramics and bioactive glasses are frequently used in orthopedic surgery to stimulate the regeneration of bone tissue due to their superior compatibility to bone tissue. Nevertheless, the brittleness and lack of self-healing behavior of bioceramics are still considered as serious drawbacks. Therefore, these bioceramics have been combined with organic biomaterials for several decades. Since the 1990s, the emergence of nanotechnology has accelerated the progress with respect to the development of organic-inorganic nanocomposites of improved functionality compared to conventional composite biomaterials. This presentation focuses on the development of injectable (nano)composites with self-healing and/or load-bearing capacity. To this end, the affinity between polymeric and inorganic components was tuned by modifying non-covalent interactions between both composite components. Specifically, we exploited reversible interactions between hydrogel matrices and inorganic nanoparticles (traditional nanocomposites), hydrogel nanoparticles and inorganic nanoparticles (colloidal nanocomposites), as well as fibers and bioceramic matrices (fiber-reinforced cement composites). The resulting composite biomaterials were mechanically strong and self-healing, which may open up new avenues of research on the applicability of self-healing and load-bearing composite biomaterials for regenerative medicine

Implant infection is an increasing problem in orthopedic surgery, especially due to progressive antibiotic resistance and an aging population with rising numbers of implantations. As a consequence, new strategies for infection prevention are necessary. In the previous study it was hypothesized that laser-structured implant surfaces favor cellular adhesion while hindering bacterial ongrowth and therewith contribute to reduce implant infections. Cuboid titanium implants (0.8 × 0.8 × 12 mm. 3. , n=34) were used. Seventeen were laser-structured by ultra-short pulsed laser ablation to create a spike structure; the others were polished and served as controls. In general anesthesia, implants were inserted in rat tibiae and infected with a S. aureus suspension. During a 21 day postoperative follow-up, daily clinical control was performed. Radiographs were taken at day 14 and day 21. After euthanasia, bacterial load and biofilm formation on the implant surface was evaluated semi quantitatively by confocal laser scanning microscopy and computational acquisition of bacteria and cells by Imaris®-software. Additionally, histology of the surrounding bone was performed. Clinically, no differences were observed between the groups. However, contrary to our hypothesis, bacterial load was increased in the laser-structured implant group although cellular adhesion was even more pronounced. Radiographical and histological evaluations showed increased bone alterations in the group with laser-structured implants compared to the control group. These findings did not confirm prior in vitro studies, where a reduction of bacterial load was found for similar surfaces and demonstrate the necessity of in vivo trials prior to the clinical use of new materials

With information about a patient's bone mechanical properties orthopaedic operations could be optimised to reduce intra- and post-operative complications. However, there is currently no reliable method of measuring a patient's bone mechanical properties in vivo. We have previously investigated microindentation, using a 1.5mm diameter spherical indenter tip, and found no correlation between these measurements and compression testing measurements. We hypothesised that by using a larger diameter indenter tip we would closer match bone millimetre-scale mechanical properties. 20 bone samples were taken from 20 patients undergoing hip replacement surgery. The samples were machined from the femoral neck calcar cortical bone into 6×3×3mm parallelepiped specimens, aligned with the osteons along the long axis. The samples were micro-computed tomography (CT) scanned to calculate porosity. Microindentation was performed using a 6mm diameter, sapphire, spherical indenter tip. 12 indentations were performed in a grid and the reduced moduli were calculated using the Oliver-Pharr method. Compression testing was then performed to failure and the apparent elastic modulus was calculated for each sample. A moderate correlation was found between the indentation reduced moduli and compression testing elastic moduli (r=0.52, r2=0.275, p=0.018). In addition, a moderate correlation was found between the indentation reduced moduli and CT-measured porosity (r=0.5, r2=0.251, p=0.025) and a strong correlation was found between compression testing moduli and porosity (r=0.75, r2=0.568, p<0.001). Using large-tip spherical microindentation, indentation reduced moduli correlated significantly with compression testing apparent elastic moduli in these 20 cortical bone specimens. Microindentation using a large, spherical indenter tip may predict the mechanical properties of bone at the millimetre length scale and shows promise as a potential future clinical decision aid in surgery

Infection is one of the most serious complications of orthopedic surgery, particularly in implant-related procedures. Minimum inhibitory concentration (MIC) for identified bacteria is an important factor for successful antibiotic treatment. We investigated the MIC of antibiotics in Staphylococcus species from orthopedic infections, comparing with isolates from respiratory medicine. Staphylococcus species isolated in our laboratory from January 2013 to July 2016 were retrospectively reviewed. The MIC of vancomycin (VCM), arbekacin (ABK), teicoplanin (TEIC), linezolid (LZD), and rifampicin (RFP) was reviewed. Differences in the MIC of each antibiotic in orthopedic and respiratory samples were determined. A total of 259 isolates were evaluated (89 orthopedic, 170 respiratory). Staphylococcus aureus was the most commonly identified species (58%). In comparison with orthopedic samples, the number of isolates with a VCM MIC <0.5 μg/ml in methicillin sensitive staphylococcus aureus (MSSA) was significantly higher in respiratory isolates, while a MIC of 2 μg/ml was significantly lower (P = 0.0078). The proportion of isolates with a VCM MIC of 2 μg/ml in methicillin-resistant coagulase-negative staphylococci (MRCNS) was significantly higher in orthopedic isolates than that seen in respiratory isolates of methicillin-resistant staphylococcus aureus (MRSA; P < 0.001). When comparing MRCNS and other orthopedic Staphylococci, the rate of RFP MIC >2 μg/ml in MRCNS isolates was significantly higher (P = 0.0058). The MIC of VCM in Staphylococcus species from orthopedic infection was higher than that of respiratory samples, particularly in MRCNS from implant-related samples. MRCNS showed a significantly higher rate of resistance for RFP versus other orthopedic isolates

Drilling through bone is a complex action that requires precise motor skills of an orthopedic surgeon. In order to minimize plunging and soft tissue damage, the surgeon must halt drill progression precisely following penetration of the far cortex. The purpose of this study was to create a low-cost and easy-to-use drilling simulator to train orthopedic residents in reducing the drill plunging depth. This prospective observational study was performed in the division of orthopedic surgery of a single tertiary medical center. The participants included 13 residents and 7 orthopedic specialists. The simulator consisted of a synthetic femur bone model and ordinary modeling clay, and the training unit consisted of a disposable plastic tube (∼US$14), clamps (∼US$58) and a power drill + drill bit (standard hospital equipment). Plunging depths were measured by the simulator and compared between orthopedic specialists, the 6 “senior residents” (3+ years) and the 7 “junior residents” during a training session. Measurements were taken again 2 weeks following the training session. Initially, the plunging depths of the junior residents were significantly greater compared to those of the orthopedic specialists (7.00 mm vs 5.28 mm, respectively, p < 0.038). There was no similarly significant difference between the senior residents and the orthopedic experts ([6.33 mm vs. 5.28 mm, respectively; p = 0.18). The senior residents achieved plunging depths of 5.17 mm at the end of the training session and 4.7 mm 2 weeks later compared to 7.14 mm at the end of the training session and 6 mm 2 weeks later for the junior residents. This study demonstrated the capability of a low-cost drilling simulator as a training model for reducing the plunging depth during the drilling of bone and soft tissue among junior and senior residents

Introduction. Today TKR is considered one of the most successful operative procedures in orthopedic surgery. Nevertheless, failure rates of 2 – 10% depending on the length of the study and the design are still reported. This provides evidence for further development in knee arthroplasty. Particularly the oxide ceramics used now in THA show major advantages due to their excellent tribological properties, their significantly reduced third-body wear as well as their high corrosion resistance. A further advantage of ceramic materials is their potential use in patients with metal allergy. Metallic wear induces immunological reactions resulting in hypersensitivity, pain, osteolysis and implant loosening. The purpose of our study was to examine the safety of the tibial component of a novel all-ceramic TKR. Materials and Methods. We tested the tibial components of the primary knee implant BPK-S Integration Ceramic. Both the tibial and the femoral component consist of BIOLOX®delta ceramic The standards ISO 14879-1 and ASTM F1800-07 describe the test set-up for the experimental fatigue strength testing of tibial components from knee implants. We conducted the testing with a significantly increased maximum load of 5,300 N (900 N are required). A final burst strength test was carried out after the fatigue load testing in the same embedding and with the same test set-up. Results. No specimen failed during fatigue load testing. The subsequent post-fatigue burst strength testing showed a maximum strength against fracture of at least 9.7 kN for size 3 and at least 12.1 kN for size 6. Discussion. The good results of the strength testing of the tibial component of the BPK-S Integration Ceramic tibial plateau supported the good initial clinical outcome without any implant specific complications of this knee design. Further clinical studies have to show if this design fulfills the high expectations over long periods of time

Background. Lack of ability in basic mobility skills is associated with increased mortality in patients with hip fractures. The aim of this study was to identify predictors for performing basic mobility skills at discharge. Methods. From June 2015 to May 2016, 235 consecutive patients (76% female, median age 85 (78–89 IQR)) with hip fractures admitted to the Department of Orthopedic Surgery at North Denmark Regional Hospital were included. Basic mobility was assessed at discharge using the Cumulated Ambulation Score (CAS), which consists of 1) getting in and out of bed, 2) rising from a chair and 3) walking. Possible scores for each task is: unable (CAS=0), supported (CAS=1) or independent (CAS=2). A total score of 6 indicates independence in basic mobility. Inclusion was restricted to first time hip fractures and age ≥65. Exclusion criteria were death during admission or unrecorded CAS at discharge. Results. Before surgery 90.6% were independent in basic mobility (CAS=6). Getting out of bed at discharge: independently 37.5%, supported 56.5% and unable 6.0%. Rising from a chair: independently 49.8%, supported 43% and unable 7.2%. Walking: independently 43.8%, supported 38.3% and unable 17.9%. A total of 79 (33.6%) patients achieved independence in all tasks (CAS=6) at discharge. Independence in: 1) getting in and out of bed, 2) rising from a chair, and 3) walking, respectively had significant association with advanced age, length of stay and Charlson Comorbidity Index >0. Medial fractures were associated with inability to rise from a chair. Advanced age was the only variable significantly associated with each task of CAS. Pre-fracture function was associated with the inability to rise from a chair and walking. Delay of surgery > 48 hours after admission was significantly associated with the inability to walk. Conclusion. Elderly patients with comorbidities and dependent pre-fracture function should receive extra attention in rehabilitation