We have designed a prospective study to evaluate the usefulness of prolonged incubation of cultures from sonicated orthopaedic implants. During the study period 124 implants from 113 patients were processed (22 osteosynthetic implants, 46 hip prostheses, 54 knee prostheses, and two shoulder prostheses). Of these, 70 patients had clinical infection; 32 had received antibiotics at least seven days before removal of the implant. A total of 54 patients had sonicated samples that produced positive cultures (including four patients without infection). All of them were positive in the first seven days of incubation. No differences were found regarding previous antibiotic treatment when analysing colony counts or days of incubation in the case of a positive result. In our experience, extending incubation of the samples to 14 days does not add more positive results for sonicated orthopaedic implants (hip and knee prosthesis and osteosynthesis implants) compared with a conventional seven-day incubation period. Cite this article: Bone Joint J 2013;95-B:1001–6

To prevent infections after orthopedic surgery, intravenous antibiotics are administered perioperatively. Cefazolin is widely used as the prophylactic antibiotic of choice. Systemic antibiotic therapy may however be less effective in longstanding surgery where bone allografts are used. Bone chips have been shown to be an effective carrier for certain types of antibiotics. Bone allografts impregnated with antibiotics may therefore provide the necessary local antibiotic levels for prophylaxis. To be efficient, a prolonged release from these bonechips is required. In contrast to vancomycin, for which prolonged release has clearly been proven effective from Osteomycin®, a commercially available impregnated bone allograft, no prolonged release bone chip preparations have been described so far for cefazolin. We developed a protocol to bind cefazolin in the porous structure of bone chips by means of a hydrogel composed of proteins naturally present in the human body. Three types of bone chips were evaluated: fresh frozen, decellularized frozen and decellularized lyophilized. Bone chips were incubated with 20 mg/ml cefazolin or treated with liquid hydrogel containing either 1 mg/ml fibrin or 1 mg/ml collagen and 20 mg/ml cefazolin. The cefazolin hydrogel was distributed in the porous structure by short vacuum treatment. Bone chips with cefazolin but without hydrogel were either incubated for 20 min- 4h or also treated with vacuum. Cefazolin elution of bone chips was carried out in fetal bovine serum and analyzed by Ultra Performance Liquid Chromatography – Diode Array Detection. Soaking of bone chips without hydrogel resulted in a quick release of cefazolin, which was limited to 4 hours. When vacuum was applied elution of >1 µg/ml cefazolin was measured for up to 36 hours. Combination with collagen hydrogel resulted in a higher cefazolin concentration released at 24 hours (3.9 vs 0.3 µg/ml), but not in a prolonged release. However, combination of decellularized frozen bone chips with fibrin hydrogel resulted in an initial release of 533 µg/ml followed by a gradual decline reaching the minimal inhibitory concentration for S. aureus at 72 hours (1.7 µg/ml), while not measurable anymore after 92 hours. Processed bone chips with hydrogel-cefazolin showed a markedly prolonged cefazolin release. When combined with a fibrin hydrogel, high initial peak levels of cefazolin were obtained, followed by a decreasing release over the following three days. This elution profile is desirable, since high initial levels are important to maximize anti-bacterial action whereas low levels of antibiotic for a limited time may stimulate osteogenesis. It is important that antibiotic release is ending after a few days as prolonged low levels of antibiotics are not clinically helpful and may lead to antibiotic resistance. Further preclinical studies are warranted to show effectiveness of hydrogel-cefazolin impregnated bone chips

Summary Statement. Prolonged presence of VEGF (released from gelatin microspheres) led to a significant increase in scaffold vascularization when applied in vivo. Bioprinted scaffolds with regional VEGF presence retained their architecture and regional vessel formation occurred. Introduction. Tissue-engineered bone constructs need timely vascularization for optimal performance in regeneration. A potent stimulus of vascularization is vascular endothelial growth factor (VEGF), a factor with a short half-life time. Controlled release of VEGF from gelatin microparticles (GMPs) was investigated as a means to prolong VEGF presence at the preferred location within bioprinted scaffolds, and study subsequent vascularization. Methods. Release of VEGF from GMPs was measured with ELISA and bioactivity was assessed using human endothelial progenitor cells (EPC) in Transwell and real-time migration assays. Matrigel scaffolds containing EPCs and VEGF, which was released either in a fast or sustained fashion by application of GMPs, were investigated for their in vivo vasculogenic capacity. In addition, regional differences with respect to VEGF release were introduced in 3D-printed EPC-laden scaffolds. Scaffolds were implanted in subcutaneous pockets in mice for 1 week and analyzed for vessel formation. Results. Release of VEGF from GMPs was continuous for 3 weeks. VEGF bioactivity was confirmed, EPC migration in the presence of GMP-released VEGF was indistinguishable from VEGF added to the medium. Implantation in subcutaneous pockets in mice demonstrated that vessel formation was significantly higher in the VEGF sustained release group when compared to fast release or control groups. In addition, the different regions in the bioprinted scaffolds were retained and vessel formation occurred analogous with the results seen in the Matrigel plugs. Discussion/Conclusion. We conclude that GMPs are suitable to generate sustained release profiles of bioactive VEGF, and that they can be used to generate defined differentiation regions in 3D printed heterogeneous constructs. The prolonged presence of VEGF led to a significant increase in scaffold vascularization when applied in vivo

Introduction. Endochondral ossification (EO) is the process of bone development via a cartilage template. It involves multiple stages, including chondrogenesis, mineralisation and angiogenesis. Importantly, how cartilage mineralisation affects angiogenesis during EO is not fully understood. Here we aimed to develop a new in vitro co-culture model to recapitulate and study the interaction between mineralised cartilage generated from human mesenchymal stromal cells (hMSCs) and microvascular networks. Method. Chondrogenic hMSC pellets were generated by culture with transforming growth factor (TGF)-β3. For mineralised pellets, β-glycerophosphate (BGP) was added from day 7 and TGF-β3 was withdrawn on day 14. Conditioned medium (CM) from the pellets was used to evaluate the effect on human umbilical vein endothelial cells (HUVECs) in migration, proliferation and tube formation assays. To perform direct co-cultures, pellets were embedded in fibrin hydrogels containing vessel-forming cells (HUVECs, adipose stromal cells) for 10 days with BGP to induce mineralisation. The pellets and hydrogels were characterised by immunohistochemistry and confocal imaging. Result. The CM from d14 chondrogenic or mineralised pellets significantly stimulated HUVEC migration and proliferation, as well as in vitro vascular network formation. When CM from pellets subjected to prolonged mineralisation (d28) was used, these effects were strongly reduced. When chondrogenic and mineralised pellets were directly co-cultured with vessel-forming cells in fibrin hydrogels, the cartilage matrix (collagen type II/X stainings) and the mineral deposition (von Kossa staining) were well preserved. Confocal imaging analyses demonstrated the formation of microvascular networks with well-formed lumina. Importantly, more microvascular structures were formed in the proximity of chondrogenic pellets than mineralized pellets. Conclusion. The angiogenic properties of tissue engineered cartilage are significantly reduced upon prolonged mineralisation. We developed a 3D co-culture model to study the role of angiogenesis in endochondral bone formation, which can have applications in disease modelling studies

Introduction and Objective. Some periprosthetic femoral fractures (PFFs) present history and radiographic aspect consistent with an atypical femoral fracture (AFF), fulfilling the criteria for AFF except that PFFs by themselves are excluded from the diagnosis of AFFs. The aim of this study was to evaluate in a single Institution series of PFFs if any of them could be considered a periprosthetic atypical femoral fracture (PAFF), and their prevalence. Materials and Methods. Surgical records were searched for PFFs around a primary hip stem from January 2013 to December 2019. Cases were classified according to Vancouver classification. Demographic and medical history were extracted. Fisher's exact test was used for statistical analysis. Results. One-hundred-fifteen PFFs were identified, 59 of them were type B1 and 16 were type C. Radiographs and medical records were available for all patients. Twenty-four patients (32%) have been treated with bisphosphonates (BPs) for longer than 4 years. Four patients presented a fracture with characteristics of PAFF. When enlarged to all PFFs of the series, no other PAFF was found: prevalence of PAFFs was 5.3% for type B1 and C cases and 3.5% for all surgically treated PFFs. Statistical significative difference between PAFFs and PFFs was found for prolonged BPs assumption and for the level of fracture clear of the stem. Conclusions. Fracture with characteristics of AFFs can also happen over a prosthetic stem, configuring themselves as PAFFs, and they are related to prolonged BPs use. As a correct diagnosis is mandatory for proper treatment, a revision of criteria for AFFs should be considered, accepting that PAFFs exist

Ankle fractures are among the most common types of fractures. If surgery is not performed within 12 to 24 hours, ankle swelling is likely to develop and delay the operative fixation. This leads to patients staying longer in the ward waiting and increased hospital occupancy. This prolonged stay has significant financial implication as well as it is frustrating for both patients and health care professionals. The aim was to formulate a pathway for the ankle fracture patients coming to the emergency department, outpatients and planned for operative intervention. To identify whether pre-operative hospital admissions of stable ankle fracture patients are reduced with the implementation of the pathway. We formulated an ankle fracture fixation pathway, which was approved for use in December 2020. A retrospective analysis of 6 months hospital admissions of ankle fracture patients in the period between January to June 2020. The duration from admission to the actual surgery was collected to review if some admissions could have been avoided and patients brought directly on the surgery day. A total of 23 patients were included. Mean age was 60.5 years and SD was 17years. 94% of patients were females. 10 patients were appropriately discharged.7 Patients were appropriately admitted. 6 Patients were unnecessarily admitted. These 6 patients were admitted on presentation to ED. Retrospective analysis of this audit showed that this cohort of patients met the safe discharge criteria and could have been discharged. Duration of unnecessary stay ranged from 1 to 11 days (21 days in total). Total saving could have been £6300. Standards were met in 74% of cases. Preoperative hospital admission could be reduced with the proposed pathway. It is a valuable tool to be used and should be implemented to reduce unnecessary hospital admissions

Infections in spine surgery are relatively common and devastating complications, a significant burden to the patient and the healthcare system. Usually, the treatment of SSIs consists of aggressive and prolonged antibiotic therapy, multiple debridements, and in chronic cases, hardware removal. Infections are correlated with worse subjective outcomes and even higher mortality. Depending on the type of spine surgery, the infection rate has been reported to be as higher as 20%. Recently silver-coated implants have been introduced in spine surgery to reduce the incidence of post-operative infections and to improve implant survivorship. The aim of the present study is to evaluate complications and outcomes in patients treated with silver-coated implants because of spine infection. All consecutive patients who had spine stabilization with a silver-coated implant from 2018 to 2021 were screened for inclusion in the study. Inclusion criteria were: (1) six months of minimum follow-up; (2) previous surgical site infection; hematogenous spondylodiscitis requiring surgical stabilization. Demographic and surgical information were obtained via chart review, all the device-related complications and the reoperation rate were also reported. A total of 57 patients were included in the present study. The mean age was 63.4 years, and there were 36 (63%) males and 21 (37%) females. Among the included cases, 57% were SSIs, 33% were spondylodiscitis, and 9% were hardware mobilization. Comorbidities such as diabetes mellitus, obesity, smoke, and oncological history were significant risk factors. In addition, the organisms cultured were Staphylococcus species in most of the cases. At six months of follow-up, 40% of patients were considered free from infection, while 20% needed multiple surgeries. The present research showed satisfactory results of silver-coated implants for the treatment of spine infection

In chronically infected fracture non-unions, treatment requires extensive debridement to remove necrotic and infected bone, often resulting in large defects requiring elaborate and prolonged bone reconstruction. One approach includes the induced membrane technique (IMT), although the differences in outcome between infected and non-infectious aetiologies remain unclear. Here we present a new rabbit humerus model for IMT secondary to infection, and, furthermore, we compare bone healing in rabbits with a chronically infected non-union compared to non-infected equivalents. A 5 mm defect was created in the humerus and filled with a polymethylmethacrylate (PMMA) spacer or left empty (n=6 per group). After 3 weeks, the PMMA spacer was replaced with a beta-tricalcium phosphate (chronOs, Synthes) scaffold, which was placed within the induced membrane and observed for a further 10 weeks. The same protocol was followed for the infected group, except that four week prior to treatment, the wound was inoculated with Staphylococcus aureus (4×10. 6. CFU/animal) and the PMMA spacer was loaded with gentamicin, and systemic therapy was applied for 4 weeks prior to chronOs application. All the animals from the infected group were culture positive during the first revision surgery (mean 3×10. 5. CFU/animal, n= 12), while at the second revision, after antibiotic therapy, all the animals were culture negative. The differences in bone healing between the non-infected and infected groups were evaluated by radiography and histology. The initially infected animals showed impaired bone healing at euthanasia, and some remnants of bacteria in histology. The non-infected animals reached bone bridging in both empty and chronOs conditions. We developed a preclinical in vivo model to investigate how bacterial infection influence bone healing in large defects with the future aim to explore new treatment concepts of infected non-union

Introduction. Distal triceps tendon rupture is related to high complication rates with up to 25% failures. Elbow stiffness is another severe complication, as the traditional approach considers prolonged immobilization to ensure tendon healing. Recently a dynamic high-strength suture tape was designed, implementing a silicone-infused core for braid shortening and preventing repair elongation during mobilization, thus maintaining constant tissue approximation. The aim of this study was to biomechanically compare the novel dynamic tape versus a conventional high-strength suture tape in a human cadaveric distal triceps tendon rupture repair model. Method. Sixteen paired arms from eight donors were used. Distal triceps tendon rupture tenotomies and repairs were performed via the crossed transosseous locking Krackow stitch technique for anatomic footprint repair using either conventional suture tape (ST) or novel dynamic tape (DT). A postoperative protocol mimicking intense early rehabilitation was simulated, by a 9-day, 300-cycle daily mobilization under 120N pulling force followed by a final destructive test. Result. Significant differences were identified between the groups regarding the temporal progression of the displacement in the distal, intermediate, and proximal tendon aspects, p<0.001. DT demonstrated significantly less displacement compared to ST (4.6±1.2mm versus 7.8±2.1mm) and higher load to failure (637±113N versus 341±230N), p≤0.037. DT retracted 0.95±1.95mm after each 24-hour rest period and withstood the whole cyclic loading sequence without failure. In contrast, ST failed early in three specimens. Conclusion. From a biomechanical perspective, DT revealed lower tendon displacement and greater resistance in load to failure over ST during simulated daily mobilization, suggesting its potential for earlier elbow mobilization and prevention of postoperative elbow stiffness

Hip joint biomechanics can be altered by abnormal morphology of the acetabulum and/or femur. This may affect load distribution and contact stresses on the articular surfaces, hence, leading to damage and degradation of the tissue. Experimental hip joint simulators have been used to assess tribology of total hip replacements and recently methods further developed to assess the natural hip joint mechanics. The aim of this study was to evaluate articular surfaces of human cadaveric joints following prolonged experimental simulation under a standard gait cycle. Four cadaveric male right hips (mean age = 62 years) were dissected, the joint disarticulated and capsule removed. The acetabulum and femoral head were mounted in an anatomical hip simulator (Simulation Solutions, UK). A simplified twin peak gait cycle (peak load of 3kN) was applied. Hips were submerged in Ringers solution (0.04% sodium azide) and testing conducted at 1 Hertz for 32 hours (115,200 cycles). Soft tissue degradation was recorded using photogrammetry at intervals throughout testing. All four hips were successfully tested. Prior to simulation, two samples exhibited articular surface degradation and one had a minor scalpel cut and a small area of cartilage delamination. The pre-simulation damage got slightly worse as the simulation continued but no new areas of damage were detected upon inspection. The samples without surface degradation, showed no damage during testing and the labral sealing effect was more obvious in these samples. The fact that no new areas of damage were detected after long simulations, indicates that the loading conditions and positioning of the sample were appropriate, so the simulation can be used as a control to compare mechanical degradation of the natural hip when provoked abnormal conditions or labral tissue repairs are simulated

We investigated factors associated with postoperative lipiduria and hypoxemia in patients undergoing surgery for orthopedic fractures. We enrolled patients who presented to our emergency department due to traumatic fractures between 2016 and 2017. We collected urine samples within 24 hours after the patients had undergone surgery to determine the presence of lipiduria. Hypoxemia was defined as an SpO2 <95% determined with a pulse oximeter during the hospitalization. Patients’ anthropometric data, medical history, and laboratory test results were collected from the electronic medical record. Logistic regression analyses were used to determine the associations of clinical factors with postoperative lipiduria and hypoxemia with multivariate adjustment. A total of 144 patients were analyzed (mean age 51.3 ± 22.9 years, male 50.7%). Diabetes (odd ratio 3.684, 95% CI 1.256-10.810, p=0.018) and operation time (odd ratio 1.005, 95% CI 1.000-1.009, p=0.029) were independently associated with postoperative lipiduria, while age (odd ratio 1.034, 95% CI 1.003-1.066, p=0.029), body mass index (odd ratio 1.100, 95% CI 1.007-1.203, p=0.035), and operation time (odd ratio 1.005, 95% CI 1.000-1.010, p=0.033) were independently associated with postoperative hypoxemia. We identified several factors independently associated with postoperative lipiduria and hypoxemia in patients with fracture undergoing surgical intervention. Operation time was associated with both postoperative lipiduria and hypoxemia, and we recommend that patients with prolonged operation for fractures should be carefully monitored for clinical signs related to fat embolism syndrome

Tourniquet is a commonly used tool in orthopaedic practice. Incidence of complications is low but if any develops, it is devastating. Transient nerve damage, ischemia or skin burns are the possible tourniquet related complications. There is big variation in practice regarding the limb occlusion pressure. 51 procedures in 50 patients were reviewed retrospectively in our district general hospital. We looked at quality of documentation guided by the BOAST standard (The Safe Use of Intraoperative Tourniquets, published in October 2021). Limb occlusion pressure and ischemic time were analysed. Intra-operative and post-operative notes were reviewed to assess quality of documentation and post-operative complications. Although limb occlusion pressure was above the recommended range in more than 75% of cases, there were no significant complications observed. Two cases only developed transient neuropraxia in common peroneal nerve and median nerve following tibial plateau ORIF and trapeziectomy simultaneously. Tibial ORIF fixation case had prolonged ischemic time (more than 120 minutes) and the limb occlusion pressure for the hand case was above the recommended range. Both have recovered within few days with no long-term consequences. Minimum documentation threshold was not met with regarding tourniquet site condition, method of skin isolation and padding, and exsanguination method. This relatively new standard with no previous similar guidance needs time until it is followed by the health care professionals especially when there is no high incidence of complications related to the use of the tourniquet. However, it is crucial to increase the theatre staff awareness of such standards. This will prevent devastating complications specifically in vulnerable patients. Adjustments to theatre checklist have been suggested to improved documentation. Additionally, local teaching sessions will be delivered to theatre personnel aiming at improving our compliance to this standard

Osteosarcoma is common in children and adolescents with high mortality due to rapid progression. Therapeutic approaches for osteosarcoma are limited and may cause side effects. Cannabinoid ligands exert antiproliferative, apoptotic effect in cancer cells via CB1/2 or TRPV1 receptors. In this study, we hypothesized that synthetic specific CB2R agonist CB65 might have an antiproliferative and apoptotic effect on osteosarcoma cell lines in vitro. If so, this agent might be a chemotherapeutic candidate for osteosarcoma, with prolonged release, increased stability and bioavailability when loaded into a liposomal system. We first determined CB2 receptor expression in MG63 and Saos-2 osteosarcoma cells by qRT- PCR and FCM. CB65 reduced proliferation in osteosarcoma cells by WST-1 and RTCA. IC50 for MG63 and Saos-2 cells were calculated as 1.11×10-11 and 4.95×10-11 M, respectively. The antiproliferative effect of CB65 on osteosarcoma cells was inhibited by CB2 antagonist AM630. IC50 of CB65 induced late apoptosis of MG63 and Saos-2 cells at 24 and 48 hours, respectively by FCM. CB65 was loaded into the liposomal system by thin film hydration method and particle size, polydispersity index, and zeta potentials were 141.7±0.6 nm, 0.451±0.026, and -10.9±0.3 mV, respectively. The CB65-loaded liposomal formulation reduced MG63 and Saos-2 cell proliferation by RTCA. IC50 of CB65 and CB65-loaded liposomal formulation induced late apoptosis of MG63 and Saos-2 cells at 24 and 48 hours, respectively, by FCM. Scratch width was higher in CB65 and CB65-loaded liposome-treated cells compared to control. In this study, the real-time antiproliferative and apoptotic effect of synthetic specific CB2 agonist CB65 in osteosarcoma cell lines was demonstrated for the first time, and the real time therapeutic window was determined. The CB65-loaded liposomal formulation presents a potential treatment option that can be translated to clinic following its validation within animal models and production under GMP conditions

Osteoporotic fracture has become a major problem in ageing population and often requires prolonged healing time. Low Intensity Pulsed Ultrasound (LIPUS) can significantly enhance fracture healing through alteration of osteocyte lacuno-canalicular network (LCN). DMP1 in osteocytes is responsible for maintaining LCN and mineralisation. This study aims to investigate osteocyte-specific DMP1's role in enhanced osteoporotic fracture healing in response to mechanical stimulation. Bilateral ovariectomy was performed in 6-month-old female SD rats to induce osteoporosis. Metaphyseal fracture was created at left distal femur using oscillating micro-saw. Rats were randomised to groups: (1) DMP1 KD, (2) DMP1 KD + LIPUS, (3) Control, or (4) Control + LIPUS, where KD stands for knockdown by injection of shRNA into marrow cavity 2 weeks before surgery. Assessments included weekly radiography, microCT and immunohistochemistry on DMP1, E11, FGF23 and sclerostin. DMP1 KD significantly impaired LIPUS-accelerated fracture healing when comparing KD + LIPUS group to Control + LIPUS group. The X-ray relative opacity showed less tissue growth at all timepoints (Week 1, 3 & 6; p=0.000, 0.001 and 0.003 respectively) and the bone volume fraction was decreased after DMP1 KD at Week 3 (p=0.006). DMP1 KD also significantly altered the expression levels of osteocyte-specific DMP1, E11, FGF23 and sclerostin during healing process. The lower relative opacity and bone volume fraction in DMP1 KD groups indicated that knockdown of DMP1 was associated with poorer fracture healing process compared to non-knockdown groups. The similar results between knockdown group with and without LIPUS showed that blockage of DMP1 would negate LIPUS-induced enhancement on fracture healing. Acknowledgment: General Research Fund (Ref: 14113018)

Introduction. Inaccurate identification of implants on X-rays may lead to prolonged surgical duration as well as increased complexity and costs during implant removal. Deep learning models may help to address this problem, although they typically require large datasets to effectively train models in detecting and classifying objects, e.g. implants. This can limit applicability for instances when only smaller datasets are available. Transfer learning can be used to overcome this limitation by leveraging large, publicly available datasets to pre-train detection and classification models. The aim of this study was to assess the effectiveness of deep learning models in implant localisation and classification on a lower limb X-ray dataset. Method. Firstly, detection models were evaluated on their ability to localise four categories of implants, e.g. plates, screws, pins, and intramedullary nails. Detection models (Faster R-CNN, YOLOv5, EfficientDet) were pre-trained on the large, freely available COCO dataset (330000 images). Secondly, classification models (DenseNet121, Inception V3, ResNet18, ResNet101) were evaluated on their ability to classify five types of intramedullary nails. Localisation and classification accuracy were evaluated on a smaller image dataset (204 images). Result. The YOLOv5s model showed the best capacity to detect and distinguish between different types of implants (accuracy: plate=82.1%, screw=72.3%, intramedullary nail=86.9%, pin=79.9%). Screw implants were the most difficult implant to detect, likely due to overlapping screw implants visible in the image dataset. The DenseNet121 classification model showed the best performance in classifying different types of intramedullary nails (accuracy=73.7%). Therefore, a deep learning model pipeline with the YOLOv5s and DenseNet121 was proposed for the most optimal performance of automating implants localisation and classification for a relatively small dataset. Conclusion. These findings support the potential of deep learning techniques in enhancing implant detection accuracy. With further development, AI-based implant identification may benefit patients, surgeons and hospitals through improved surgical planning and efficient use of theatre time

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

Determine the infection risk of nonoperative versus operative repair of extraperitoneal bladder ruptures in patients with pelvic ring injuries. Pelvic ring injuries with extraperitoneal bladder ruptures were identified from a prospective trauma registry at two level 1 trauma centers from 2014 to 2020. Patients, injuries, treatments, and complications were reviewed. Using Fisher's exact test with significance at P value < 0.05, associations between injury treatment and outcomes were determined. Of the 1127 patients with pelvic ring injuries, 68 (6%) had a concomitant extraperitoneal bladder rupture. All patients received IV antibiotics for an average of 2.5 days. A suprapubic catheter was placed in 4 patients. Bladder repairs were performed in 55 (81%) patients, 28 of those simultaneous with ORIF anterior pelvic ring. The other 27 bladder repair patients underwent initial ex-lap with bladder repair and on average had pelvic fixation 2.2 days later. Nonoperative management of bladder rupture with prolonged Foley catheterization was used in 13 patients. Improved fracture reduction was noted in the ORIF cohort compared to the closed reduction external fixation cohort (P = 0.04). There were 5 (7%) deep infections. Deep infection was associated with nonoperative management of bladder rupture (P = 0.003) and use of a suprapubic catheter (P = 0.02). Not repairing the bladder increased odds of infection 17-fold compared to repair (OR 16.9, 95% CI 1.75 – 164, P = 0.01). Operative repair of extraperitoneal bladder ruptures substantially decreases risk of infection in patients with pelvic ring injuries. ORIF of anterior pelvic ring does not increase risk of infection and results in better reductions compared to closed reduction. Suprapubic catheters should be avoided if possible due to increased infection risk later. Treatment algorithms for pelvic ring injuries with extraperitoneal bladder ruptures should recommend early bladder repair and emphasize anterior pelvic ORIF

Fracture nonunion is a severe clinical problem for the patient, as well as for the clinician. About 5-20% of fractures does not heal properly after more than six months, with a 19% nonunion rate for tibia, 12% for femur and 13% for humerus, leading to patient morbidity, prolonged hospitalization, and high costs. The standard treatment with iliac crest-derived autologous bone filling the nonunion site may cause pain or hematoma to the patient, as well as major complications such as infection. The application of mesenchymal autologous cells (MSC) to improve bone formation calls for randomized, open, two-arm clinical studies to verify safety and efficacy. The ORTHOUNION * project (ORTHOpedic randomized clinical trial with expanded bone marrow MSC and bioceramics versus autograft in long bone nonUNIONs) is a multicentric, open, randomized, comparative phase II clinical trial, approved in the framework of the H2020 funding programme, under the coordination of Enrique Gòmez Barrena of the Hospital La Paz (Madrid, Spain). Starting from January 2017, patients with nonunion of femur, tibia or humerus have been actively enrolled in Spain, France, Germany, and Italy. The study protocol encompasses two experimental arms, i.e., autologous bone marrow-derived mesenchymal cells after expansion (‘high dose’ or ‘low dose’ MSC) combined to ceramic granules (MBCP™, Biomatlante), and iliac crest-derived autologous trabecular bone (ICAG) as active comparator arm, with a 2-year follow-up after surgery. Despite the COVID 19 pandemic with several lockdown periods in the four countries, the trial was continued, leading to 42 patients treated out of 51 included, with 11 receiving the bone graft (G1 arm), 15 the ‘high dose’ MSC (200x10. 6. , G2a arm) and 16 the ‘low dose’ MSC (100x10. 6. , G2b arm). The Rizzoli Orthopaedic Institute has functioned as coordinator of the Italian clinical centres (Bologna, Milano, Brescia) and the Biomedical Science and Technologies and Nanobiotechnology Lab of the RIT Dept. has enrolled six patients with the collaboration of the Rizzoli’ 3rd Orthopaedic and Traumatological Clinic prevalently Oncologic. Moreover, the IOR Lab has collected and analysed the blood samples from all the patients treated to monitor the changes of the bone turnover markers following the surgical treatment with G1, G2a or G2b protocols. The clinical and biochemical results of the study, still under evaluation, are presented. * ORTHOUNION Horizon 2020 GA 733288

Adverse events (AEs) are still a major problem in spinal surgery, despite advances in surgical techniques, innovative technologies available and the introduction of checklist and predictive score systems aimed at reducing surgical complications. We previously analysed the results of the introduction of the WHO Safety Surgical Checklist (SSC) in our Institution, comparing the incidence of complications between two periods: from January to December 2010 (without checklist) and from January 2011 and December 2012 (with checklist), in order to assess the checklist effectiveness. The sample size was 917 patients with an average of 30 months of follow-up. Complications were observed in 107 patients (11.6%) among 917 spinal surgery procedures performed, with 159 (17.3%) complications in total. The overall incidence of complications for trauma, infectious pathology, oncology, and degenerative disease was 22.2%, 19.2%, 18.4%, and 15.3%, respectively. We observed a reduction of the overall incidence of complications following the introduction of the WHO Surgical Checklist: in 2010 without checklist, the incidence of complications was 24.2%, while in 2011 and 2012, following the checklist introduction, the incidence of complications was 16.7% and 11.7%, respectively (mean 14.2%) (p<0.0005). Thus, the SSC appeared to be an effective tool to reduce complications in spinal surgery and we proposed to extend the use of checklist system also to the pre-operative and post-operative phases in order to further reduce the incidence of complications. We also believe that a correct capture and classification of complications is fundamental to generate a clinical decision support system aimed at improving patients’ safety in spinal surgery. In the period between January 2017 and January 2018 we prospectively recorded the adverse events and complications of patients undergoing spinal surgery in our department, without using any collection system. Then we retrospectively recorded the intraoperative and postoperative adverse events of surgically treated patients during the same one-year period, using the SAVES v2 system introduced by Rampersaud and collaborators (Rampersaud YR et al. J Neurosurg Spine 2016 Aug; 25 (2): 256-63) to classify them. In the one-year period from January 2017 to January 2018 a total of 336 patients underwent spinal surgery: 223 for degenerative conditions and 113 for spinal tumors. Comorbidities were collected (Charlson Comorbidity Index [CCI]). Overall, a higher number of adverse events (AEs) was recorded using SAVES compared to the prospective recording without the use of any capture system and the increased number was statistically significant for early postoperative AEs (138/336 vs 44/336, p<0.001). 210 adverse events were retrospectively recorded using the SAVES system (30 intraoperative adverse events, 138 early postoperative and 42 late postoperative adverse events). 99 patients (29.5%) on the cohort had at least one complication. Furthermore, the correlation between some risk factors and the onset of complications or the prolonged length of stay was statistically analyzed. The risk factors taken into account were: age, presence of comorbidities (CCI), ASA score, previous surgery at the same level, type of intervention, location of the disease, duration of the surgery. In particular, the duration of the surgery (more than 3 hours) and the presence of previous surgeries resulted to be risk factors for complications in multivariate analyses

Osteoarthritis (OA) is the most common type of arthritis and causes a significant deterioration in patients’ quality of life. The high prevalence of OA as well as the current lack of disease-modifying drugs led to a rise in regenerative medicine efforts. The hope is that this will provide a treatment modality with the ability to alter the course of OA via structural modifications of damaged articular cartilage (AC). Regenerative therapy in OA starts with the concept that administered cells may engraft to a lesion site and differentiate into chondrocytes. However, recent studies show that cells, particularly when injected in suspension, rapidly undergo apoptosis after exerting a transient paracrine effect. If the injected stem cells do not lead to structural improvements of a diseased joint, the high cost of cell therapy for OA cannot be justified, particularly when compared with other injection therapeutics such as corticosteroids and hyaluronic acid. Long-term survival of implanted cells that offer prolonged paracrine effects or possible engraftment is essential for a successful cell therapy that will offer durable structural improvements. In this talk, the history and current status of regenerative therapy in OA are summarized along with the conceptual strategy and future directionsfor a successful regenerative therapy that can provide structural modifications in OA