Septic complications are on the rise and aseptic loosening has decreased in total joint arthroplasty: an updated complication based analysis using worldwide arthroplasty registers.

INTRODUCTION: A decade ago, a comprehensive study was conducted to investigate the reasons for revision surgeries and their respective frequencies in cases of total hip arthroplasty (THA) and total knee arthroplasty (TKA) based on a complication-based analysis of joint replacement registries. The aim of the present study was to determine whether the causes and risks of their occurrence have changed over the last ten years and to present an updated analysis. MATERIALS AND METHODS: A systematic review of national arthroplasty registries from seven countries examined the causes and rates of revisions of THA and TKA. The study focused on a descriptive analysis that provided an updated overview without statistical significance values. RESULTS: The most common causes for revisions of THA were aseptic loosening (35.1%), deep infection (18.2%), dislocation/instability (15.9%), and periprosthetic fractures (11.4%). The most common causes for revisions of TKA were deep infection (21.6%), aseptic loosening (18.3%), instability (14.1%), and pain (10.9%). CONCLUSION: The findings of this study revealed significant shifts in the underlying causes of revision surgeries in the last decade. Notably, septic complications emerged as the predominant reason for revision of primary TKA, while they also gained prominence as a cause of failure of THA. Although aseptic loosening remains the primary cause for re-operation of THA, the relative risk has decreased for both THA and TKA.

What Is the Impact of Multimodal Treatment in Patients with Leiomyosarcoma of Bone? A Multicenter Study of 35 Patients with an Ultra-Rare Tumor Entity.

Primary leiomyosarcoma of bone (LMSoB) is extremely rare, comprising only <0.7% of primary malignant bone tumors, and is therefore considered an ultra-rare tumor entity. There is currently no consensus as to whether therapeutic strategies should be based on the biological characteristics of soft tissue leiomyosarcoma or on primary tumor localization in the bone. The use of perioperative chemotherapy and its effectiveness in this rare tumor entity remains unclear. We aimed to evaluate the impact of different treatment approaches in a multicenter setting with a total of 35 patients included. The 5-year overall survival (OS) was 74%. Patients with localized disease undergoing surgery had a significantly higher 5-year OS compared to patients who did not undergo surgical treatment (82% vs. 0%, p = 0.0015). Axial tumor localization was associated with worse event-free survival (EFS) probability (p < 0.001) and OS (p = 0.0082). A high proportion of our patients developed secondary metastases. Furthermore, the perioperative chemotherapy protocols applied to our patients were not associated with an improved EFS or OS. Therefore, the benefit of perioperative chemotherapy in LMSoB needs to be further investigated, and the choice of agents still needs to be clarified.

Artificial intelligence large language model ChatGPT: is it a trustworthy and reliable source of information for sarcoma patients?

Introduction: Since its introduction in November 2022, the artificial intelligence large language model ChatGPT has taken the world by storm. Among other applications it can be used by patients as a source of information on diseases and their treatments. However, little is known about the quality of the sarcoma-related information ChatGPT provides. We therefore aimed at analyzing how sarcoma experts evaluate the quality of ChatGPT's responses on sarcoma-related inquiries and assess the bot's answers in specific evaluation metrics. Methods: The ChatGPT responses to a sample of 25 sarcoma-related questions (5 definitions, 9 general questions, and 11 treatment-related inquiries) were evaluated by 3 independent sarcoma experts. Each response was compared with authoritative resources and international guidelines and graded on 5 different metrics using a 5-point Likert scale: completeness, misleadingness, accuracy, being up-to-date, and appropriateness. This resulted in maximum 25 and minimum 5 points per answer, with higher scores indicating a higher response quality. Scores ≥21 points were rated as very good, between 16 and 20 as good, while scores ≤15 points were classified as poor (11-15) and very poor (≤10). Results: The median score that ChatGPT's answers achieved was 18.3 points (IQR, i.e., Inter-Quartile Range, 12.3-20.3 points). Six answers were classified as very good, 9 as good, while 5 answers each were rated as poor and very poor. The best scores were documented in the evaluation of how appropriate the response was for patients (median, 3.7 points; IQR, 2.5-4.2 points), which were significantly higher compared to the accuracy scores (median, 3.3 points; IQR, 2.0-4.2 points; p = 0.035). ChatGPT fared considerably worse with treatment-related questions, with only 45% of its responses classified as good or very good, compared to general questions (78% of responses good/very good) and definitions (60% of responses good/very good). Discussion: The answers ChatGPT provided on a rare disease, such as sarcoma, were found to be of very inconsistent quality, with some answers being classified as very good and others as very poor. Sarcoma physicians should be aware of the risks of misinformation that ChatGPT poses and advise their patients accordingly.

Comparison of revision rates and epidemiological data of a single total knee arthroplasty system of different designs (cruciate retaining, posterior stabilized, mobile bearing, and fixed bearing): a meta-analysis and systematic review of clinical trials and national arthroplasty registries.

BACKGROUND: This study aimed to meta-analyze epidemiological data, revision rates, and incidences of different designs of a single Total Knee Arthroplasty System and compare these factors across different countries. METHODS: A systematic review was conducted on clinical studies and arthroplasty registries of ATTUNE TKA from 1999 to 2020. The main endpoints analyzed were revision rates and epidemiological data. RESULTS: The average age of patients was 67.8 years, with a gender distribution of 60% female and 40% male. The pooled average BMI was 29.4 kg/m2. Eight clinical studies showed a pooled revision rate per 100 observed CY of 0.5 (n = 1343 cases). Cumulative revision rates after 1, 3, and 5 years varied among registries, with the Swiss registry having the highest revision data (after 5 years: 6.3%) and the American registry having the lowest revision data (after 5 years: 1.7%). A comparison of the revision rates of mobile bearing and fixed bearing (41,200 cases) as well as cruciate retaining and posterior stabilized (n = 123,361 cases) showed no significant advantage in the first 5 years after implantation. CONCLUSION: In conclusion, pooled data from 41,200 cases of TKA with a single Total Knee Arthroplasty System in two arthroplasty registries revealed that there was no significant difference in revision rates between the mobile bearing and fixed bearing design within the first 5 years after implantation. In addition, a comparison of the revision rates in n = 123,361 cases showed no significant advantage for cruciate retaining or posterior stabilized in the first 5 years after implantation.

Delayed Meniscus Repair Lowers the Functional Outcome of Primary ACL Reconstruction.

BACKGROUND: Our purpose was to evaluate whether the time of intervention and the type of meniscus surgery (repair vs. partial meniscectomy) play a role in managing anterior cruciate ligament (ACL) reconstructions with concurrent meniscus pathologies. METHODS: We performed a prospective cohort study which differentiated between early and late ACL reconstructions with a cut-off at 3 months. Patients were re-evaluated after 2 years. RESULTS: Thirty-nine patients received an operation between 2-12 weeks after the injury, and thirty patients received the surgery between 13-28 weeks after trauma. The strongest negative predictive factor of the International Knee Documentation Committee subjective knee form in a hierarchical regression model was older age (ß = -0.49 per year; 95% CI [-0.91; -0.07]; p = 0.022; partial R2 = 0.08)). The strongest positive predictive factor was a higher preoperative Tegner score (ß = 3.6; 95% CI [0.13; 7.1]; p = 0.042; partial R2 = 0.07) and an interaction between meniscus repair surgery and the time of intervention (ß = 27; 95% CI [1.6; 52]; p = 0.037; partial R2 = 0.07), revealing a clinical meaningful difference as to whether meniscus repairs were performed within 12 weeks after trauma or were delayed. There was no difference whether partial meniscectomy was performed early or delayed. CONCLUSIONS: Surgical timing plays a crucial role when surgeons opt for a meniscus repair rather than for a meniscectomy.

30-day and one-year readmission rate in 11,270 patients with surgical treatment for proximal femoral fractures across Austria.

Aims: Patients with proximal femoral fractures (PFFs) are often multimorbid, thus unplanned readmissions following surgery are common. We therefore aimed to analyze 30-day and one-year readmission rates, reasons for, and factors associated with, readmission risk in a cohort of patients with surgically treated PFFs across Austria. Methods: Data from 11,270 patients with PFFs, treated surgically (osteosyntheses, n = 6,435; endoprostheses, n = 4,835) at Austrian hospitals within a one-year period (January to December 2021) was retrieved from the Leistungsorientierte Krankenanstaltenfinanzierung (Achievement-Oriented Hospital Financing). The 30-day and one-year readmission rates were reported. Readmission risk for any complication, as well as general medicine-, internal medicine-, and surgery/injury-associated complications, and factors associated with readmissions, were investigated. Results: The 30-day and one-year readmission rates due to any complication were 15% and 47%, respectively. The 30-day readmission rate (p = 0.001) was higher in endoprosthesis than osteosynthesis patients; this was not the case for the one-year readmission rate (p = 0.138). Internal medicine- (n = 2,273 (20%)) and surgery/injury-associated complications (n = 1,612 (14%)) were the most common reason for one-year readmission. Regardless of the surgical procedure, male sex was significantly associated with higher readmission risk due to any, as well as internal medicine-associated, complication. Advanced age was significantly associated with higher readmission risk after osteosynthesis. In both cohorts, treatment at mid-sized hospitals was significantly associated with lower readmission risk due to any complication, while prolonged length of stay was associated with higher one-year readmission risks due to any complication, as well as internal-medicine associated complications. Conclusion: Future health policy decisions in Austria should focus on optimization of perioperative and post-discharge management of this vulnerable patient population.

A comparative study assessing the efficacy and safety of radiofrequency ablation versus surgical treatment for osteoid osteoma: retrospective analysis in a single institution.

OBJECTIVE: We aim to evaluate the efficacy of CT-guided percutaneous radiofrequency ablation (RFA) and surgical treatment in osteoid osteoma (OO) treated at the Medical University of Graz. MATERIALS AND METHODS: In a single-institution study, we analysed data from January 2005 to January 2021 of patients with histological/radiological diagnosis of OO. CT and MRI scans were reviewed for typical findings. Means (with SD) and medians (with IQR) were reported for normally and non-normally distributed variables. Differences between groups were assessed using chi-squared tests and t-tests. RESULTS: One hundred nineteen patients (mean age: 21.6 ± 10.9 years; 63.9% males) with confirmed OO were retrospectively evaluated. 73 and 43 patients underwent RFA and surgery, respectively. In three cases, RFA combined with surgery was performed. Pre-intervention, 103 patients (88.8%) had undergone CT, and 101 had an MRI (87.1%). The nidus was confirmed in 82.5% of cases with CTs (85/103) and 63.4% with MRIs (64/101). The majority of nidi were located cortically (n = 96; 82.8%), most frequently in the femur (38 patients, 33.3%) with a median size of 8.0 mm (IQR: 5.0-12.0 mm). Median symptom duration before treatment was 6.0 (IQR: 4.0-13.0) months. The complication rate was 12.1% (14/116; 15.1% RFA vs. 7.0% surgery; p = 0.196). In total, 11.2% of patients had persistent symptoms after one week with clinical success rates of RFA and surgery, 86.3% and 90.7% (p = 0.647), respectively. CONCLUSION: Compared to surgical treatment, CT-guided percutaneous RFA is a safe, minimally invasive, reliable, and efficient treatment option for OO. CRITICAL RELEVANCE STATEMENT: This article critically assesses the diagnosis and treatment of osteoid osteoma, emphasising accurate imaging, and detailing a non-invasive option for effective management. KEY POINTS: • This study analyses 116 cases of OO at one institution, focusing on symptom persistence, recurrence in short-term follow-up, and complications in two study groups. • Surgery showed higher, though not statistically significant, success despite comparable symptom persistence; CT displayed typical OO features more than MRI, regardless of the intramedullary, cortical and subperiosteal location as well as the site of the affected bone. • CT-guided RFA is an effective therapeutic alternative for OO compared to surgical intervention. In case of atypical OO appearance, RFA is not the first-line treatment.

Occupational injuries in orthopedic and trauma surgeons in Austria.

BACKGROUND: The aim of this study was to investigate the frequency and type of injuries during the career of orthopedic and trauma surgeons in Austria. The hypothesis was that the percentage of occupational injuries among orthopedic and trauma surgeons aligns with the incidence reported in the United States, thus indicating the need for a workplace prevention program. METHODS: A web-based survey was created to collect all necessary data and was sent to all orthopedic and trauma surgeons in Austria via e-mail. Relevant parameters included the surgeons' age, work experience, severity of pain, type of injury, and current pain. Descriptive and explorative statistical analysis was performed. RESULTS: A web-based survey was sent to 1122 board-certified orthopedic surgeons and residents in Austria via e-mail. In total, the response rate was 135 (12%). Seventy-two surgeons (54%) had suffered from one or more occupational injuries during their career. We detected a significant raise of occupational injuries related to the work life duration in which operations were performed and the prevalence of injuries. Most injuries of surgeons were reported between 21 and 30 years of their professional life. According to the frequency at different locations, the distribution in descending order was 25% with injuries of the hand, 22% of finger(s), 12% of the foot, 10% of the spine, 2% of the neck, 3% of the head, and 2% of the abdomen. A causality of incapacity to work through injuries at the workplace was given as 4%. Four percent stated a sick leave of at least 3 weeks. In 7% of the facilities, there was no optimization of preventive measures following an occupational injury. We found no correlation of injuries and resident status. CONCLUSION: Orthopedic surgeons in Austria show a high incidence of occupational injuries in line with the findings of colleagues from the United States. The impact on the health system consists of absenteeism in the workplace of highly specialized health service providers as well as the incapacity to work of a high quality, highly trained workforce of at least 4%. With more preventive measures and more attention and care in the rehabilitation phase after such injuries, a positive effect could be achieved. We believe that residents should be specifically trained on how to avoid such injuries.

Restoring Tibial Slope and Sagittal Alignment of the Femoral Component in Unrestricted Kinematically Aligned Total Knee Arthroplasty Using Conventional versus Patient-Specific Instrumentation.

Restoring sagittal alignment in kinematically aligned (KA) total knee arthroplasty (TKA) is crucial to avoid patellofemoral joint instability or overstuffing and to restore an adequate range of motion. This prospective study compared the accuracy of conventional instrumentation (CI) versus patient-specific instrumentation (PSI) in restoring sagittal alignment of KA TKA measured by the tibial slope and degree of flexion of the femoral component to the sagittal femoral axis. One hundred patients were randomized to receive either CI (n = 50) or PSI (n = 50) for KA TKA. Two observers measured pre- and postoperative X-rays to assess restoration of the tibial slope and sagittal flexion. Inter- and intraclass correlations were calculated, and postoperative tibial and femoral components were compared with preoperative anatomy. In 50 CI patients, 86% (n = 43) had the tibial slope restored exactly, and no deviation more than 1 degree was found. Deviations of 0 to 1 degree were detected in 14% (n = 7). In 50 patients of the PSI group, 56% (n = 28) achieved an exact anatomic tibial slope restoration and 20% (n = 10) showed a deviation more than 2 degrees compared with the preoperative measurement. Deviations ranging between 0 to 1 and 1 to 2 degrees were found in 22% (n = 11) and 2% (n = 1) of cases, respectively. Sagittal alignment of the femoral component showed in both groups no deviation exceeding 1 degree. The restoration of sagittal alignment in KA TKA was statistically significantly differently distributed between CI and PSI (p = < 0.001) without clinical relevance. We found that PSI increased the odds for deviations >2 degrees in tibial slope reconstructions from 0 to 0.20 ([95% confidence interval: 0.09-0.31]; p = 0.001). Both CI and PSI revealed adequate results with respect to restoring sagittal alignment of the tibial and femoral components in KA TKA. The conventional technique requires adequate adjustment of the intramedullary rod to avoid hyperflexion of the femoral component and attention must be paid when restoring the tibial slope using PSI. This is a prospective Level II study.

Accuracy of Conventional Instrumentation is Dependent on Alignment Philosophy Using the Identical Surgical Technique in Total Knee Arthroplasty.

The objective of this prospective study was to assess the precision of restoring the anatomical tibial obliquity, as measured by the medial proximal tibial angle (MPTA) on conventional X-rays, in relation to the surgical technique employed. Specifically, the study aimed to compare the accuracy of tibial obliquity restoration between kinematic alignment (KA) and conventional mechanical alignment (MA) in total knee arthroplasty (TKA). Two-hundred-and-sixty patients underwent either mechanically aligned TKA (n = 139) or kinematically aligned TKA (n = 121) using conventional instrumentation (CI). Pre- and postoperative X-rays were measured twice by two observers, with a 2-week interval. Inter- and intraclass correlations were calculated, and postoperative tibial obliquity was compared to the preoperative anatomy. In the group of 139 patients with mechanically aligned TKA, no cases with an MPTA deviation greater than 1 degree from 90 degrees were observed. Sixteen percent of the cases (n = 22) had a deviation of 0 to 1 degree. The remaining 84% of the cases (n = 117) had their MPTA of 90 degrees achieved. In the group of 121 patients with kinematically aligned TKA, no cases had a deviation greater than 1 degree compared with the preoperative MPTA. Thirty-one percent of the cases (n = 37) had a deviation of 0 to 1 degree with respect to preoperative MPTA. The remaining 69% of the cases (n = 84) had their tibial obliquity restored. Mechanically aligned TKA revealed statistically significant smaller deviations of accuracy compared to kinematically aligned TKA (p = 0.005). The inter- and intraclass correlations indicated substantial agreement of all measurements (intraclass correlation coefficient [ICC] < 0.90). Both mechanically aligned and kinematically aligned TKA demonstrated satisfactory outcomes in terms of restoring tibial obliquity or a neutral MPTA of 90 degrees using CI. However, MA showed superior results regarding precision compared to KA. When starting with kinematical alignment using CI, the surgeons should be aware that the learning curve according to accuracy differs to MA. It was a Prospective Level II study.

Development of application and surgical technique of total knee arthroplasties: a systematic comparative analysis using worldwide registers.

PURPOSE: The aim was to compare total knee arthroplasty (TKA) between countries with regard to epidemiologic data and surgical technique by the use of worldwide registers and compare findings with a previous report after one decade. METHODS: A systematic search was carried out in November 2022 and compared to previous reports from 2010. We extracted data regarding implanted TKAs, patients' age distribution, procedure types, fixation and revision rates. After identification of 28 national arthroplasty registers, 8of them, namely Australia, Canada, Denmark, England and Wales, New Zealand, Norway, Scotland and Sweden, offered sufficient data and were included in final analysis. RESULTS: A large variation was found in the annual number of implantations per 100,000 inhabitants with a range from 77 to 210.2 (mean 132.8). The fixation type varied strongly as well, e.g. over 95% of totally cemented TKAs in Sweden versus 61.2% cemented fixation in Denmark. Another significant difference was the use of patellar resurfacing in TKA, ranging from 47.3% (Canada) using a patellar button in TKA to less than 5% (Sweden). Within the period of one decade, the mean overall number of annual implantations increased (10%), whilst relative number of revisions decreased, the use of cemented TKA decreased from 87 to 74%, and the use of patella button remained largely inhomogeneous. CONCLUSION: Comparison of arthroplasty registers revealed large differences regarding the annual number of primary TKAs per inhabitant as well as primary TKA procedure types with an increase of annual implantations, decrease of relative number of revisions, and a decrease of the use of cemented systems over the period of one decade.

Long-term clinical and radiological outcome of a cementless titanium-coated total knee arthroplasty system.

INTRODUCTION: To ensure a high-quality standard, it is important to frequently evaluate different prostheses models to avoid prostheses with high failure rates. Thus, the aim of the study was to evaluate the long-term outcome of the uncemented titanium-coated total knee arthroplasty (TKA) system (Advanced Coated System (ACS) III, Implantcast, GERMANY). We hypothesized that the ACS III would have a similar performance as other cemented TKA systems. MATERIALS AND METHODS: A total of 540 ACS III mobile-bearing knee joint prostheses were implanted in 495 patients. The visual analogue scale (VAS) score, Tegner activity score (TAS), knee society score (KSS), Western Ontario and McMaster (WOMAC) score, and the Short Form 12 (SF-12) score for the evaluation of quality of life (QoL) were taken after at least 9 years of follow-up. In addition, we measured range of motion (ROM) and assessed potential sex differences. In addition, the survival analysis was calculated at a median follow-up of 16.7 years. RESULTS: At the final follow-up, 142 patients had died, and 38 had been lost to follow-up. The rate of revision-free implant survival at 16.7 years was 90.0% (95% CI 87.1-92.2%) and the rate of infection-free survival was 97.0% (IQR 95.2-98.2%). The reasons for revision surgery were aseptic loosening (32.9%), followed by infection (27.1%), inlay exchange (15.9%), and periprosthetic fractures (5.7%). At the clinical follow-up visit, the mean VAS score was 1.9 ± 1.9, the median TAS was 3 (IQR 2-4), and the mean KSS for pain and function were 83.5 ± 15.3 and 67.5 ± 25.2, respectively. The mean WOMAC score was 81.1 ± 14.9, and the median SF-12 scores for physical and mental health were 36.9 (IQR 29.8-45.1) and 55.8 (IQR 46.2-61.0), respectively. The mean knee flexion was 102.0° ± 15.4°. Male patients had better clinical outcome scores than female patients [SF-12 mental health score, p = 0.037; SF-12 physical health score, p = 0.032; KSS pain score (p < 0.001), and KSS functional score (p < 0.001)]. CONCLUSION: The ACS III TKA system is a suitable option for the treatment of end-stage osteoarthritis of the knee joint because of its adequate long-term survival. Our findings are in line with published data on similar TKA systems that have shown favourable clinical scores in males. LEVEL OF EVIDENCE: Level III-Retrospective cohort study.

Evaluation of Neuropathic Pain after Total Knee Arthroplasty: Do Yellow Flags Matter?

Up to 20% of total knee arthroplasty (TKA) patients continue to experience chronic postsurgical pain. Various factors have been identified as potential contributors, including so-called "yellow flags", encompassing symptoms of depression, anxiety, and catastrophizing, which were examined in this study to assess their predictive value concerning functional outcomes after TKA. METHODS: Fifty TKA patients were categorized into high-risk and low-risk groups based on clinical assessment, demographic data, medication, and patient-reported outcome measures (DN4, SF-36, WOMAC, NRS, Fibromyalgia Survey Questionnaire, Pain Catastrophizing Scale, and Hospital Anxiety and Depression Scale). Postoperative outcomes within six months after TKA were then compared. RESULTS: Both groups exhibited significant (p < 0.001) improvements in all WOMAC and NRS subscales, as well as in the physical function, role physical, pain, and energy/fatigue subdomains of the SF-36 after six months, while the high-risk group showed lower WOMAC scores regarding stiffness (19.0 ± 18.3 vs. 27.2 ± 20.7, p < 0.001) and pain (13.5 ± 13.3 vs. 15.1 ± 16.3, p = 0.029). The high-risk group showed significantly worse preoperative DN4 scores (1.8 ± 1.3 vs. 3.0 ± 1.1, p = 0.002) than the low-risk group, which persisted for one day (2.3 ± 1.2 vs. 3.5 ± 1.5, p = 0.005) and six weeks (2.2 ± 1.9 vs. 3.6 ± 2.3, p = 0.041) postoperatively. CONCLUSIONS: Our results indicate that pre-existing yellow flags contribute to a more challenging early postoperative phase, underscoring the importance of considering individual patient characteristics and psychological factors to optimize TKA outcomes.

The Biological Assessment of Shikonin and ß,ß-dimethylacrylshikonin Using a Cellular Myxofibrosarcoma Tumor Heterogeneity Model.

Myxofibrosarcoma (MFS) is a subtype of soft tissue sarcoma of connective tissue, which is characterized by large intra-tumor heterogeneity. Therapy includes surgical resection. Additional chemotherapy is of limited effect. In this study, we demonstrated the potent anticancer activity of shikonin derivatives in our MFS cellular model of tumor heterogeneity for developing a new therapeutic approach. The impact of shikonin and ß,ß-dimethylacrylshikonin (DMAS) on viability, apoptotic induction, MAPK phosphorylation, and DNA damage response were analyzed by means of two human MFS cell lines, MUG-Myx2a and MUG-Myx2b, derived from a singular tumor tissue specimen. MFS cells showed a dose-dependent inhibition of cell viability and a significant induction of apoptosis. Treatment with shikonin derivatives caused an inhibition of pSTAT3 and an increase in pAKT, pERK, pJNK, and pp38. DMAS and shikonin inhibited the activation of the two master upstream regulators of the DNA damage response, ATR and ATM. MUG-Myx2b, which contains an additional PTEN mutation, was more sensitive in some targets. These data demonstrate the significant antitumorigenic effect of shikonin derivatives in MFS and highlight the importance of intra-tumor heterogeneity in treatment planning.

Vancomycin Elution Kinetics of Four Antibiotic Carriers Used in Orthopaedic Surgery: In Vitro Study over 42 Days.

This study aimed to analyse and compare the vancomycin elution kinetics of four biodegradable, osteoconductive antibiotic carriers used in clinical practice within a 42-day in vitro setting. Carriers A and D already contained vancomycin (1.1 g and 0.247 g), whereas carriers B and C were mixed with vancomycin according to the manufacturer's recommendations (B: 0.83 g and C: 0.305 g). At nine time points, 50% (4.5 mL) of the elution sample was removed and substituted with the same amount of PBS. Probes were analysed with a kinetic microparticle immunoassay. Time-dependent changes in vancomycin concentrations for each carrier and differences between carriers were analysed. Mean initial antibiotic levels were highest for carrier A (37.5 mg/mL) and lowest for carrier B (5.4 mg/mL). We observed time-dependent, strongly negative linear elution kinetics for carriers A (-0.835; p < 0.001), C (-0.793; p < 0.001), and D (-0.853; p < 0.001). Vancomycin concentrations increased from 48 h to 7 d and dropped thereafter in carriers C and D whilst constantly decreasing at any time point for carrier A. Carrier B showed a shallower decrease. Mean antibiotics levels at 42 d were 1.5 mg/mL, 2.6 mg/mL, 0.1 mg/mL, and 0.1 mg/mL for carriers A, B, C, and D. Differences in mean initial and final vancomycin concentrations for carrier A were significantly larger in comparison to C (p = 0.040). A carrier consisting of allogenic bone chips showed the highest vancomycin-to-carrier ratio and the largest elution over the study period. Whilst vancomycin concentrations were still measurable at 42 days for all carriers, carrier A provided a higher drug-to-carrier ratio and a more consistent antibiotic-releasing profile.

Effect of radiotherapy on local recurrence, distant metastasis and overall survival in 1200 extremity soft tissue sarcoma patients. Retrospective analysis using IPTW-adjusted models.

BACKGROUND AND PURPOSE: Neoadjuvant (NRTX) and adjuvant radiotherapy (ARTX) reduce local recurrence (LR) risk in extremity soft tissue sarcoma (eSTS), yet their impact on distant metastasis (DM) and overall survival (OS) is less well defined. This study aimed at analysing the influence of NRTX/ARTX on all three endpoints using a retrospective, multicentre eSTS cohort. MATERIALS AND METHODS: 1200 patients (mean age: 60.7 ± 16.8 years; 44.4 % females) were retrospectively included, treated with limb sparing surgery and curative intent for localised, high grade (G2/3) eSTS. 194 (16.2 %), 790 (65.8 %), and 216 (18.0 %) patients had received NRTX, ARTX and no RTX, respectively. For the resulting three groups (no RTX vs. NRTX, no RTX vs. ARTX, NRTX vs. ARTX) Fine&Gray models for LR and DM, and Cox-regression models for OS were calculated, with IPTW-modelling adjusting for imbalances between groups. RESULTS: In the IPTW-adjusted analysis, NRTX was associated with lower LR-risk in comparison to no RTX (SHR [subhazard ratio]: 0.236; p = 0.003), whilst no impact on DM-risk (p = 0.576) or OS (p = 1.000) was found. IPTW-weighted analysis for no RTX vs. ARTX revealed a significant positive association between ARTX and lower LR-risk (SHR: 0.479, p = 0.003), but again no impact on DM-risk (p = 0.363) or OS (p = 0.534). IPTW-weighted model for NRTX vs. ARTX showed significantly lower LR-risk for NRTX (SHR for ARTX: 3.433; p = 0.003) but no difference regarding DM-risk (p = 1.000) or OS (p = 0.639). CONCLUSION: NRTX and ARTX are associated with lower LR-risk, but do not seem to affect DM-risk or OS. NRTX may be favoured over ARTX as our results indicate better local control rates.

The Enigma of Atypical Cartilaginous Tumors: Surgery or Surveillance?

During the last 20 years, the treatment of atypical cartilaginous tumors (ACTs) of the long bones has undergone a dramatic change: while these formerly called chondrosarcomas G1 previously led to wide resections and big reconstructions with megaprostheses, today, the use curettage of the lesions and filling the defect e [...].

Effect of Local Adjuvants Following Curettage of Benign and Intermediate Tumours of Bone: A Systematic Review of the Literature.

Local adjuvants are used upon intralesional resection of benign/intermediate bone tumours, aiming at reducing the local recurrence (LR) rate. However, it is under debate whether, when and which local adjuvants should be used. This PRISMA-guideline based systematic review aimed to analyse studies reporting on the role of adjuvants in benign/intermediate bone tumours. All original articles published between January 1995 and April 2020 were potentially eligible. Of 344 studies identified, 58 met the final inclusion criteria and were further analysed. Articles were screened for adjuvant and tumour type, follow-up period, surgical treatment, and development of LR. Differences in LR rates were analysed using chi-squared tests. Altogether, 3316 cases (10 different tumour entities) were analysed. Overall, 32 different therapeutic approaches were identified. The most common were curettage combined with high-speed burr (n = 774; 23.3%) and high-speed burr only (n = 620; 18.7%). The LR rate for studies with a minimum follow-up of 24 months (n = 30; 51.7%) was 12.5% (185/1483), with the highest rate found in GCT (16.7%; 144/861). In comparison to a combination of curettage, any adjuvant and PMMA, the sole application of curettage and high-speed burr (p = 0.015) reduced the LR rate in GCT. The overall complication rate was 9.6% (263/2732), which was most commonly attributable to postoperative fracture (n = 68) and osteoarthritis of an adjacent joint during follow-up (n = 62). A variety of adjuvants treatment options are reported in the literature. However, the most important step remains to be thorough curettage, ideally combined with high-speed burring.

Proton and Carbon Ion Irradiation Changes the Process of Endochondral Ossification in an Ex Vivo Femur Organotypic Culture Model.

Particle therapy (PT) that utilizes protons and carbon ions offers a promising way to reduce the side effects of radiation oncology, especially in pediatric patients. To investigate the influence of PT on growing bone, we exposed an organotypic rat ex vivo femur culture model to PT. After irradiation, histological staining, immunohistochemical staining, and gene expression analysis were conducted following 1 or 14 days of in vitro culture (DIV). Our data indicated a significant loss of proliferating chondrocytes at 1 DIV, which was followed by regeneration attempts through chondrocytic cluster formation at 14 DIV. Accelerated levels of mineralization were observed, which correlated with increased proteoglycan production and secretion into the pericellular matrix. Col2α1 expression, which increased during the cultivation period, was significantly inhibited by PT. Additionally, the decrease in ColX expression over time was more pronounced compared to the non-IR control. The chondrogenic markers BMP2, RUNX2, OPG, and the osteogenic marker ALPL, showed a significant reduction in the increase in expression after 14 DIV due to PT treatment. It was noted that carbon ions had a stronger influence than protons. Our bone model demonstrated the occurrence of pathological and regenerative processes induced by PT, thus building on the current understanding of the biological mechanisms of bone.