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Background: Children and young adults needing surgery for a primary malignant bone tumour around the knee face a difficult, life-changing decision. A previous study showed that this population wants to be involved more in the decision-making process and that more involvement leads to less decisional stress and regret. Therefore, a well-designed and standardized decision-making process based on the principles of shared decision-making needs to be designed, implemented, and evaluated., Methods: We developed a shared decision-making (SDM) model for this patient population, including an online decision aid (DA). This model has been implemented in the standard care of patients with a primary malignant bone tumour around the knee. Following implementation, we will analyse its effect on the decision-making process and the impact on patient experiences using questionnaires and interviews. Moreover, potential areas for improvement will be identified., Discussion: Given the importance of involving patients and parents in surgical decision-making, particularly in life-changing surgery such as malignant bone tumour surgery, and given the lack of SDM models applicable for this purpose, we want to share our model with the international community, including our study protocol for evaluating and optimising the model. This study will generate valuable knowledge to facilitate the optimisation of current patient care for local treatment. The sharing of our implementation and study protocol can serve as an example for other centres interested in implementing SDM methods in an era characterized by more empowered patients and parents who desire autonomy and reliable and realistic information., (© 2024. The Author(s).)

Background: Due to the relatively advanced age and high mortality rate of patients with high-grade chondrosarcoma (CS), it is important to holistically assess patient- and tumor characteristics in multidisciplinary team and shared decision-making with regard to treatment options. While current prognostic models include multiple tumor and treatment characteristics, the only patient characteristics that are commonly included are age and gender. Based on clinical experience, we believe that factors related to patient preoperative systemic health status such as the American Society of Anesthesiologists (ASA) score may be equally important prognostic factors for overall survival (OS). Methods: A retrospective nationwide cohort study was identified from four specialized bone sarcoma centers in The Netherlands. Patients with a primary CS grade II, III, and dedifferentiated CS were eligible. Prognostic factors including age at presentation, gender, ASA score, CVD, tobacco use, BMI, histological tumor grade, tumor size, pathological fracture, presentation after unplanned excision, type of surgery and surgical margin were evaluated. The outcome measure was OS at the time of surgery. The Kaplan-Meier methodology was employed to estimate OS; a log-rank test was used to assess the difference in survival. To study the impact of prognostic factors on OS, a multivariate Cox proportional hazard regression model was estimated. Results: In total, 249 patients were eligible for this study, and 89 were deceased at the end of follow-up. In multivariate analysis, histological grade (HR 2.247, 95% CI 1.334-3.783), ASA score III (HR 2.615, 95% CI 1.145-5.976, vs. ASA I), and age per year (HR: 1.025, 95% CI 1.004-1.045) were negatively associated with OS. No association was found between tobacco use, BMI, gender or cardiovascular disease and OS in this cohort. Pathological fracture and tumor size were only associated with OS in univariate analysis. Conclusions: This multicenter study is the first on sarcomas to include ASA in a prognostic model. Results show that ASA score as a proxy for patients' systemic health status should be included when providing a prognosis for patients with a high-grade primary CS, besides the conventional risk factors such as tumor grade and age. Specifically, severe systemic disease (ASA score III) is a strong negative predictor. Conversely, we found no difference in OS between ASA scores I and II. These findings aid multidisciplinary team and shared decision-making with regard to these complex sarcoma patients that often require life-changing surgeries. Level of Evidence: Prognostic level III. See the instructions for authors for the complete description of levels of evidence.

Background: Bone metastases are on the rise due to longer survival of cancer patients. Local tumor control is required for pain relief. Microwave ablation (MWA) is a technique for minimally invasive local tumor treatment. Tumor tissue is destroyed by application of local hyperthermia to induce necrosis. Given the most common setting of palliative care, it is generally considered beneficial for patients to start mobilizing directly following treatment. No data on mechanical strength in long bones after MWA have been published so far., Materials and Methods: In- and ex-vivo experiments on sheep tibias were performed with MWA in various combinations of settings for time and power. During the in-vivo part sheep were sacrificed one or six weeks after ablation. Mechanical strength was examined with a three-point bending test for ablations in the diaphysis and with an indentation test for ablations in the metaphysis., Results: MWA does not decrease mechanical strength in the diaphysis. In the metaphysis strength decreased up to 50% six weeks after ablation, which was not seen directly after ablation., Conclusion: MWA appears to decrease mechanical strength in long bone metaphysis up to 50% after six weeks, however strength remains sufficient for direct mobilization. The time before normal strength is regained after the remodeling phase is not known., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Nijland et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background and Purpose: Periprosthetic femoral fracture (PPF) after total hip arthroplasty (THA) is a serious complication, as it often is followed by functional deficits and morbidity. There is no consensus regarding the optimal stem fixation method and whether additional cup replacement is beneficial. The aim of our study was to perform a direct comparison of reasons and risk of re-revision between cemented and uncemented revision THAs following PPF using registry data., Patients and Methods: 1,879 patients registered in the Dutch Arthroplasty Registry (LROI) who underwent a first-time revision for PPF between 2007 and 2021 (cemented stem: n = 555; uncemented stem: n = 1,324) were included. Competing risk survival analysis and multivariable Cox proportional hazard analyses were performed., Results: 5- and 10-year crude cumulative incidence of re-revision following revision for PPF was similar between cemented (resp. 13%, 95% CI 10-16 and 18%, CI 13-24) and uncemented (resp. 11%, CI 10-13 and 13%, CI 11-16) revisions. Multivariable Cox regression analysis, adjusting for potential confounders, showed a similar risk of revision for uncemented and cemented revision stems. Finally, we found no difference in risk of re-revision between a total revision (HR 1.2, 0.6-2.1) compared with a stem revision., Conclusion: We found no difference in the risk of re-revision between cemented and uncemented revision stems after revision for PPF.

Background : Differentiation between uncomplicated and complicated postoperative wound drainage after arthroplasty is crucial to prevent unnecessary reoperation. Prospective data about the duration and amount of postoperative wound drainage in patients with and without prosthetic joint infection (PJI) are currently absent. Methods : A multicentre cohort study was conducted to assess the duration and amount of wound drainage in patients after arthroplasty. During 30 postoperative days after arthroplasty, patients recorded their wound status in a previously developed wound care app and graded the amount of wound drainage on a 5-point scale. Data about PJI in the follow-up period were extracted from the patient files. Results : Of the 1019 included patients, 16 patients (1.6 %) developed a PJI. Minor wound drainage decreased from the first to the fourth postoperative week from 50 % to 3 %. Both moderate to severe wound drainage in the third week and newly developed wound drainage in the second week after a week without drainage were strongly associated with PJI (odds ratio (OR) 103.23, 95 % confidence interval (CI) 26.08 to 408.57, OR 80.71, 95 % CI 9.12 to 714.52, respectively). The positive predictive value (PPV) for PJI was 83 % for moderate to heavy wound drainage in the third week. Conclusion : Moderate to heavy wound drainage and persistent wound drainage were strongly associated with PJI. The PPV of wound drainage for PJI was high for moderate to heavy drainage in the third week but was low for drainage in the first week. Therefore, additional parameters are needed to guide the decision to reoperate on patients for suspected acute PJI., Competing Interests: The contact author has declared that none of the authors has any competing interests., (Copyright: © 2023 Henk Scheper et al.)

Background : prompt recognition and identification of the causative microorganism in acute septic arthritis of native and prosthetic joints is vital to increase the chances of successful treatment. The aim of this study was to independently assess the diagnostic accuracy of the multiplex BIOFIRE ® Joint Infection (JI) Panel (investigational use only) in synovial fluid for rapid diagnosis. Methods : synovial fluid samples were collected at the University Medical Center Groningen from patients who had a clinical suspicion of a native septic arthritis, early acute (post-operative, within 3 months after arthroplasty) periprosthetic joint infection (PJI) or late acute (hematogenous, ≥ 3 months after arthroplasty) PJI. JI Panel results were compared to infection according to Musculoskeletal Infection Society criteria and culture-based methods as reference standard. Results : a total of 45 samples were analysed. The BIOFIRE JI Panel showed a high specificity (100 %, 95 % confidence interval (CI): 78-100) in all patient categories. Sensitivity was 83 % (95 % CI: 44-97) for patients with a clinical suspicion of native septic arthritis ( n = 12 ), 73 % (95 % CI: 48-89) for patients with a clinical suspicion of a late acute PJI ( n = 14 ), and 30 % (95 % CI: 11-60) for patients with a clinical suspicion of an early acute PJI ( n = 19 ). Conclusion : the results of this study indicate a clear clinical benefit of the BIOFIRE JI Panel in patients with a suspected native septic arthritis and late acute (hematogenous) PJI, but a low clinical benefit in patients with an early acute (post-operative) PJI due to the absence of certain relevant microorganisms, such as Staphylococcus epidermidis , from the panel., Competing Interests: At least one of the (co-)authors is a member of the editorial board of . The peer-review process was guided by an independent editor. No external funding was received for the study. Manufacturer bioMérieux was not involved in the execution of experiments or the analysis of the results. The BIOFIRE Joint Infection Panel was provided to the researchers cost-free by manufacturer bioMérieux., (Copyright: © 2023 Jorrit Willem Adriaan Schoenmakers et al.)

Introduction: A risk factor for the failure of surgical debridement in patients with early periprosthetic joint infections (PJI) is the presence of multidrug-resistant microorganisms. Staphylococcus epidermidis is one of the most isolated microorganisms in PJI and is associated with emerging resistance patterns. We aimed to assess the antibiotic resistance patterns of S. epidermidis in early PJIs treated with surgical debridement and correlate them to clinical outcomes., Material and Methods: A retrospective multicentre observational study was conducted to evaluate patients with an early PJI (within 3 months after the index arthroplasty) by S. epidermidis with at least two positive intraoperative cultures. Clinical failure was defined as the need for additional surgical intervention or antibiotic suppressive therapy to control the infection., Results: A total of 157 patients were included. The highest rate of resistance was observed for methicillin in 82% and ciprofloxacin in 65% of the cases. Both were associated with a higher rate of clinical failure (41.2% vs. 12.5% (p 0.048) and 47.3% vs. 14.3% (p 0.015)), respectively. Furthermore, 70% of the cases had reduced susceptibility to vancomycin (MIC ≥ 2), which showed a trend towards a higher failure rate (39.6% vs. 19.0%, NS). Only 7% of the cases were rifampin-resistant. Only the resistance to fluoroquinolones was an independent risk factor for clinical failure in the multivariate analysis (OR 5.45, 95% CI 1.67-17.83)., Conclusion: S. epidermidis PJIs show a high rate of resistance. Resistance to fluoroquinolones is associated with clinical failure. Alternative prophylactic antibiotic regimens and optimising treatment strategies are needed to improve clinical outcomes.

Aim: Follow-up strategies for high-grade bone sarcomas have been optimized to facilitate early detection of local recurrence and distant metastasis. The ideology is that early detection enables early treatment presuming better survival. However, the clinical value for each individual patient remains questionable. This study aims to evaluate oncological events after initial treatment in order to assess current follow-up strategies for high-grade bone sarcomas in the Netherlands., Patients and Methods: A retrospective cohort study was conducted based on a national registry. All cases were retrieved from the Netherlands Cancer Registry. Our study consisted of 393 patients treated between 2007 and 2011 with complete follow-up data. Baseline characteristics were analysed for all entities. Local recurrence and distant metastasis was analysed along with overall survival for high-grade chondrosarcoma, high-grade osteosarcoma, Ewing sarcoma and chordoma., Results: Median follow-up was 8,3 years for high-grade chondrosarcoma, 4,9 for high-grade osteosarcoma, 3,8 for Ewing sarcoma and 7,5 for chordoma. Median time to local recurrence and distant metastasis was 1,2 years for high-grade osteosarcoma and 1,5 years for Ewing sarcoma. For high-grade osteosarcoma with localized disease at presentation, 0.09 new distant metastatic events per patient per year were seen after five years of follow-up with 11,1 patients needed to follow-up for any event. Five-year overall survival was 60,0% for high-grade chondrosarcoma, 50,0% for high-grade osteosarcoma, 45,3% for Ewing sarcoma and 71,4% for chordoma., Conclusions: This nationwide study shows a plateau in local recurrences and distant metastatic events after four years of treatment for patients with high-grade osteosarcoma and Ewing sarcoma. Due to a lack of reliable evidence however, we were not able to provide additional guidance on follow-up intervals and duration. Collaborative research with larger groups is needed in order to provide a solid scientific recommendation for follow-up in the heterogenous patient population with bone sarcoma., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 The Authors.)

Background: Radiofrequency ablation (RFA) is a minimally invasive technique used for the treatment of neoplasms, with a growing interest in the treatment of bone tumours. However, the lack of data concerning the size of the resulting ablation zones in RFA of bone tumours makes prospective planning challenging, needed for safe and effective treatment., Methods: Using retrospective computed tomography and magnetic resonance imaging data from patients treated with RFA of atypical cartilaginous tumours (ACTs), the bone, tumours, and final position of the RFA electrode were segmented from the medical images and used in finite element models to simulate RFA. Tissue parameters were optimised, and boundary conditions were defined to mimic the clinical scenario. The resulting ablation diameters from postoperative images were then measured and compared to the ones from the simulations, and the error between them was calculated., Results: Seven cases had all the information required to create the finite element models. The resulting median error (in all three directions) was -1 mm, with interquartile ranges from -3 to 3 mm. The three-dimensional models showed that the thermal damage concentrates close to the cortical wall in the first minutes and then becomes more evenly distributed., Conclusions: Computer simulations can predict the ablation diameters with acceptable accuracy and may thus be utilised for patient planning. This could allow interventional radiologists to accurately define the time, electrode length, and position required to treat ACTs with RFA and make adjustments as needed to guarantee total tumour destruction while sparing as much healthy tissue as possible., (© 2022. The Author(s) under exclusive licence to European Society of Radiology.)

Periprosthetic joint infection (PJI) is a devastating complication of joint arthroplasty surgery. Treatment success depends on accurate diagnostics, adequate surgical experience and interdisciplinary consultation between orthopedic surgeons, plastic surgeons, infectious disease specialists and medical microbiologists. For this purpose, we initiated the Northern Infection Network for Joint Arthroplasty (NINJA) in the Netherlands in 2014. The establishment of a mutual diagnostic and treatment protocol for PJI in our region has enabled mutual understanding, has supported agreement on how to treat specific patients, and has led to clarity for smaller hospitals in our region for when to refer patients without jeopardizing important initial treatment locally. Furthermore, a mutual PJI patient database has enabled the improvement of our protocol, based on medicine-based evidence from our scientific data. In this paper we describe our NINJA protocol.Level of evidence: III., (© 2022. The Author(s).)

The purpose of this retrospective study was to compare two standardized protocols for radiological follow-up (in-brace versus out-of-brace radiographs) to study the rate of curve progression over time in surgically treated idiopathic scoliosis (IS) patients after failed brace treatment. In-brace radiographs have the advantage that proper fit of the brace and in-brace correction can be evaluated. However, detection of progression might theoretically be more difficult. Fifty-one IS patients that underwent surgical treatment after failed brace treatment were included. For 25 patients, follow-up radiographs were taken in-brace. For the other 26 patients, brace treatment was temporarily stopped before out-of-brace follow-up radiographs were taken. Both groups showed significant curve progression compared to baseline after a mean follow-up period of 3.4 years. The protocol with in-brace radiographs was noninferior regarding curve progression rate over time. The estimated monthly Cobb angle progression based on the mixed-effect model was 0.5 degrees in both groups. No interaction effect was found for time, and patients' baseline Cobb angle ( p = 0.98), and for time and patients' initial in-brace correction ( p = 0.32). The results of this study indicate that with both in-brace and out-of-brace protocols for radiographic follow-up, a similar rate of curve progression can be expected over time in IS patients with failed brace treatment.

Background : A low-grade periprosthetic joint infection (PJI) may present without specific symptoms, and its diagnosis remains a challenge. Three-phase bone scintigraphy (TPBS) and white blood cell (WBC) scintigraphy are incorporated into recently introduced diagnostic criteria for PJI, but their exact value in diagnosing low-grade PJI in patients with nonspecific symptoms remains unclear. Methods : In this retrospective study, we evaluated patients with a prosthetic joint of the hip or knee who underwent TPBS and/or WBC scintigraphy between 2009 and 2016 because of nonspecific symptoms. We reviewed and calculated diagnostic accuracy of the TPBS and/or WBC scintigraphy to diagnose or exclude PJI. PJI was defined based on multiple cultures obtained during revision surgery. In patients who did not undergo revision surgery, PJI was ruled out by clinical follow-up of at least 2 years absent of clinical signs of infection based on MSIS 2011 criteria. Results : A total of 373 patients were evaluated, including 340 TPBSs and 142 WBC scintigraphies. Thirteen patients (3.5 %) were diagnosed with a PJI. TPBS sensitivity, specificity, and positive and negative predictive values (PPV, NPV) were 71 %, 65 %, 8 % and 98 %, respectively. Thirty-five percent of TPBS showed increased uptake. Stratification for time intervals between the index arthroplasty and the onset of symptoms did not alter its diagnostic accuracy. WBC scintigraphy sensitivity, specificity, PPV and NPV were 30 %, 90 %, 25 % and 94 %, respectively. Conclusion : Nuclear imaging does not have clear added value in patients with low a priori chance of periprosthetic joint infection., Competing Interests: Some of the authors are members of the editorial board of . The peer-review process was guided by an independent editor, and the authors also have no other competing interests to declare., (Copyright: © 2022 Karsten D. Ottink et al.)

Introduction : Chronic osteomyelitis is a challenging condition in the orthopedic practice and traditionally treated using local and systemic antibiotics in a two-stage surgical procedure. With the introduction of the antimicrobial biomaterial S53P4 bioactive glass (Bonalive ® ), chronic osteomyelitis can be treated in a one-stage procedure. This study evaluated the mid-term clinical results of patients treated with S53P4 bioactive glass for long bone chronic osteomyelitis. Methods : In this prospective multi-center study, patients from two different university medical centers in the Netherlands were included. One-stage treatment consisted of debridement surgery, implantation of S53P4 bioactive glass, and treatment with culture-based systemic antibiotics. If required, wound closure by a plastic surgeon was performed. The primary outcome was the eradication of infection, and a secondary statistical analysis was performed on probable risk factors for treatment failure. Results : In total, 78 patients with chronic cavitary long bone osteomyelitis were included. Follow-up was at least 12 months (mean 46; standard deviation, SD, 20), and 69 patients were treated in a one-stage procedure. Overall infection eradication was 85 %, and 1-year infection-free survival was 89 %. Primary closure versus local/muscular flap coverage is the only risk factor for treatment failure. Conclusion : With 85 % eradication of infection, S53P4 bioactive glass is an effective biomaterial in the treatment of chronic osteomyelitis in a one-stage procedure. A major risk factor for treatment failure is the necessity for local/free muscle flap coverage. These results confirm earlier published data, and together with the fundamentally different antimicrobial pathways without antibiotic resistance, S53P4 bioactive glass is a recommendable biomaterial for chronic osteomyelitis treatment and might be beneficial over other biomaterials., Competing Interests: The contact author has declared that neither they nor their co-authors have any competing interests, with the exception of Jan A. P. Geurts and Jacobus J. J. Arts, who are members of the clinical advisory board of Bonalive Ltd., Turku, Finland., (Copyright: © 2021 Tom A. G. Van Vugt et al.)

Aims: The number of convolutional neural networks (CNN) available for fracture detection and classification is rapidly increasing. External validation of a CNN on a temporally separate (separated by time) or geographically separate (separated by location) dataset is crucial to assess generalizability of the CNN before application to clinical practice in other institutions. We aimed to answer the following questions: are current CNNs for fracture recognition externally valid?; which methods are applied for external validation (EV)?; and, what are reported performances of the EV sets compared to the internal validation (IV) sets of these CNNs?, Methods: The PubMed and Embase databases were systematically searched from January 2010 to October 2020 according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The type of EV, characteristics of the external dataset, and diagnostic performance characteristics on the IV and EV datasets were collected and compared. Quality assessment was conducted using a seven-item checklist based on a modified Methodologic Index for NOn-Randomized Studies instrument (MINORS)., Results: Out of 1,349 studies, 36 reported development of a CNN for fracture detection and/or classification. Of these, only four (11%) reported a form of EV. One study used temporal EV, one conducted both temporal and geographical EV, and two used geographical EV. When comparing the CNN's performance on the IV set versus the EV set, the following were found: AUCs of 0.967 (IV) versus 0.975 (EV), 0.976 (IV) versus 0.985 to 0.992 (EV), 0.93 to 0.96 (IV) versus 0.80 to 0.89 (EV), and F1-scores of 0.856 to 0.863 (IV) versus 0.757 to 0.840 (EV)., Conclusion: The number of externally validated CNNs in orthopaedic trauma for fracture recognition is still scarce. This greatly limits the potential for transfer of these CNNs from the developing institute to another hospital to achieve similar diagnostic performance. We recommend the use of geographical EV and statements such as the Consolidated Standards of Reporting Trials-Artificial Intelligence (CONSORT-AI), the Standard Protocol Items: Recommendations for Interventional Trials-Artificial Intelligence (SPIRIT-AI) and the Transparent Reporting of a multivariable prediction model for Individual Prognosis or Diagnosis-Machine Learning (TRIPOD-ML) to critically appraise performance of CNNs and improve methodological rigor, quality of future models, and facilitate eventual implementation in clinical practice. Cite this article: Bone Jt Open  2021;2(10):879-885.

Background and purpose - Custom triflange acetabular components (CTACs) are suggested as good solutions for large acetabular defects in revision total hip arthroplasty. However, high complication rates have been reported and most studies are of limited quality. This prospective study evaluates the performance of a CTAC in patients with large acetabular defects including pelvic discontinuity.Patients and methods - Prospectively collected data of 49 consecutive patients (50 hips), who underwent an acetabular revision with a CTAC were analyzed. Follow-up (FU) was 2 years. The median age of the patients was 68 years (41-89) and 41 were women. Primary outcomes were re-revision of the CTAC and differences between the modified Oxford Hip Score (mOHS) preoperatively and at 2-year follow-up. Secondary outcomes included several patient-reported outcomes (PROMs), radiological results, complications, and a comparison between hips with and without pelvic discontinuity (PD).Results - 1 patient (1 hip) was lost to the 2-year FU. No CTAC needed re-revision. The preoperative and 2-year FU mOHS were available in 40 hips and improved statistically significantly. All of the other secondary outcomes improved over time. 5 hips (of 45 with radiological 2-year FU) had loosening of screws. 8 hips had complications, including 3 persistent wound leakage, 3 pelvic fractures, and 1 dislocation. The mOHS and complication rate were similar in hips with and without PD.Interpretation - Reconstruction of large acetabular defects with and without PD with this CTAC showed good improvement in patient-reported daily functioning, high patient-reported satisfaction, few complications, and no re-revisions at 2-year FU.

Background: Radiofrequency ablation (RFA) is a minimally invasive alternative in the treatment of bone tumors. Long-term follow-up has not been described in current literature. Detailed analysis of mid- and long-term follow-up after RFA treatment for a cohort of patients with low-grade cartilaginous tumors (atypical cartilaginous tumors and enchondroma) was performed. The results, complications, and development of halo dimensions over time are presented., Methods: Data of all patients with an RFA procedure for an ACT between 2007-2018 were included. Ablation area is visible on baseline MRI, 3 months post-procedure, and is called halo. Volume was measured on MR images and compared to different follow-up moments to determine the effect of time on halo volume. Follow-up was carried out 3 months and 1, 2, 5, and 7 years after the procedure. Occurrence of complications and recurrences were assessed., Results: Of the 137 patients included, 82 were analyzed. Mean follow-up time was 43.6 months. Ablation was complete in 73 cases (89.0%). One late complication occurred, while no recurrences were seen. Halo dimensions of height, width, and depth decreased with a similar rate, 21.5% on average in the first year. Subsequently, this decrease in halo size continues gradually during follow-up, indicating bone revitalization., Conclusion: RFA is a safe and effective treatment in low-grade cartilaginous tumors with an initial success rate of 89.0%. Extended follow-up shows no local recurrences and gradual substitution of the halo with normal bone.

Percutaneous image-guided biopsy currently has a central role in the diagnostic work-up of patients with suspected spondylodiscitis. However, on the basis of recent evidence, the value of routine image-guided biopsy in this disease can be challenged. In this article, we discuss this recent evidence and also share a new diagnostic algorithm for spondylodiscitis that was recently introduced at our institution. Thus, we may move from a rather dogmatic approach in which routine image-guided biopsy is performed in any case to a more individualized use of this procedure., (© 2021 by American Journal of Neuroradiology.)

Objective: To assess organization of care in several bone sarcoma centers in Europe affiliated with the European Musculoskeletal Oncology Society (EMSOS) for comparison and to identify potential improvements in organization of care., Methods: Data for this observational cross-sectional study was obtained through healthcare professionals affiliated to EMSOS. The authors formulated 10 questions regarding organization of care. The questions were focused on guidance, multidisciplinary decision-making, and data storage. A digital questionnaire was synthesized and included quality control. The digital questionnaire was sent to 54 representative members of EMSOS. We did not receive responses from 29 representative countries (53.7%) after one digital invitation and two digital reminders., Results: We received data from 25 representatives of bone sarcoma centers from 17 countries across Europe (46.3%). Authorization to perform oncological care in a bone sarcoma center was government issued in 41.2% of cases and based on expertise without governmental influence in 52.9% of cases. In 64.7% of the countries, a national bone tumor guideline regarding for diagnosis and treatment is used in oncological care. A national bone tumor board for extensive case evaluation including classification and advice for treatment is available for 47.1% of the countries. All participating bone sarcoma centers have a mandatory local multidisciplinary meeting before the start of treatment; in 84.0% this meeting takes place once a week. During this multidisciplinary meeting a median of 15 cases (range, 4-40 cases) are discussed. In terms of storage of oncological data, a local registry is used in eight countries (47.1%). A national registry is used in eight countries (47.1%)., Conclusions: A national bone tumor board gives bone sarcoma centers with little adherence the opportunity to gain knowledge from a more experienced team. Centralization of care in a bone sarcoma center is important to lower incidences. The optimal size for a bone sarcoma center in terms of patient adherence is not known at present., (© 2020 The Authors. Orthopaedic Surgery published by Chinese Orthopaedic Association and John Wiley & Sons Australia, Ltd.)

Background: Follow-up of high-grade bone sarcoma patients with repeated radiological imaging aims at early detection of recurrent disease or distant metastasis. Repeated radiological imaging does expose (mostly young) patients to ionising radiation. At this point, it is not known whether frequent follow-up increases overall survival. Additionally, frequent follow-up subjects patients and families to psychological stress. This study aims to assess follow-up procedures in terms of frequency and type of imaging modalities in bone tumour centres across Europe for comparison and improvement of knowledge as a first step towards a more uniform approach towards bone sarcoma follow-up., Methods: Data were obtained through analysis of several follow-up protocols and a digital questionnaire returned by EMSOS members of bone tumour centres all across Europe., Results: All participating bone tumour centres attained a minimum follow-up period of ten years. National guidelines revealed variations in follow-up intervals and use of repeated imaging with ionising radiation. A local and a chest X-ray were obtained at 47.6% of the responding clinics at every follow-up patient visit., Conclusions: Variations were seen among European bone sarcoma centres with regards to follow-up intervals and use of repeated imaging. The majority of these expert centres follow existing international guidelines and find them sufficient as basis for a follow-up surveillance programme despite lack of evidence. Future research should aim towards evidence-based follow-up with focus on the effects of follow-up strategies on health outcomes, cost-effectiveness, and individualised follow-up algorithms., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2020 Louren M. Goedhart et al.)

Lessons Learned: Adjuvant treatment with zoledronic acid did not decrease the recurrence rate of giant cell tumor of bone (GCTB) in this study. The efficacy could not be determined because of the small sample size.GCTB recurrences, even in the denosumab era, are still an issue; therefore, a randomized study exploring the efficacy of zoledronic acid in the adjuvant setting in GCTB is still valid., Background: Bisphosphonates are assumed to inhibit giant cell tumor of bone (GCTB)-associated osteoclast activity and have an apoptotic effect on the neoplastic mononuclear cell population. The primary objective of this study was to determine the 2-year recurrence rate of high-risk GCTB after adjuvant zoledronic acid versus standard care., Methods: In this multicenter randomized open-label phase II trial, patients with high-risk GCTB were included (December 2008 to October 2013). Recruitment was stopped because of low accrual after the introduction of denosumab. In the intervention group, patients received adjuvant zoledronic acid (4 mg) intravenously at 1, 2, 3, 6, 9, and 12 months after surgery., Results: Fourteen patients were included (intervention n = 8, controls n = 6). Median follow-up was long: 93.5 months (range, 48-111). Overall 2-year recurrence rate was 38% (3/8) in the intervention versus 17% (1/6) in the control group ( p = .58). All recurrences were seen within the first 15 months after surgery., Conclusion: Adjuvant treatment with zoledronic acid did not decrease the recurrence rate of GCTB in this study. The efficacy could not be determined because of the small sample size. Because recurrences, even in the denosumab era, are still an issue, a randomized study exploring the efficacy of zoledronic acid in the adjuvant setting in GCTB is still valid., (© AlphaMed Press; the data published online to support this summary are the property of the authors.)

Background: Obese patients are more likely to develop periprosthetic joint infection (PJI) after primary total joint arthroplasty. This study compared the clinical and microbiological characteristics of non-obese, obese and severely obese patients with early PJI, in order to ultimately optimize antibiotic prophylaxis and other prevention measures for this specific patient category., Methods: We retrospectively evaluated patients with early PJI of the hip and knee treated with debridement, antibiotics and implant retention (DAIR) between 2006 and 2016 in three Dutch hospitals. Only patients with primary arthroplasties indicated for osteoarthritis were included. Early PJI was defined as an infection that developed within 90 days after index surgery. Obesity was defined as a BMI ≥30kg/m2 and severe obesity as a BMI ≥35kg/m2., Results: A total of 237 patients were analyzed, including 64 obese patients (27.0%) and 62 severely obese patients (26.2%). Compared with non-obese patients, obese patients had higher rates of polymicrobial infections (60.3% vs 33.3%, p<0.001) with more often involvement of Enterococcus species (27.0% vs 11.7%, p = 0.003). Moreover, severely obese patients had more Gram-negative infections, especially with Proteus species (12.9% vs 2.3%, p = 0.001). These results were only found in periprosthetic hip infections, comprising Gram-negative PJIs in 34.2% of severely obese patients compared with 24.7% in obese patients and 12.7% in non-obese patients (p = 0.018)., Conclusions: Our results demonstrate that obese patients with early periprosthetic hip infections have higher rates of polymicrobial infections with enterococci and Gram-negative rods, which stresses the importance of improving preventive strategies in this specific patient category, by adjusting antibiotic prophylaxis regimens, improving disinfection strategies and optimizing postoperative wound care., Competing Interests: The authors have declared that no competing interests exist.

Background: Grade I or low-grade chondrosarcoma (LGCS) is a primary bone tumour with low malignant potential. Historically, it was treated by wide resection, since accurate pre-operative exclusion of more aggressive cancers can be challenging and under-treatment of a more aggressive cancer could negatively influence oncological outcomes. Intralesional surgery for LGCS has been advocated more often in the literature over the past few years. The potential advantages of less aggressive treatment are better functional outcome and lower complication rates although these need to be weighed against the potential for compromising survival outcomes., Objectives: To assess the benefits and harms of intralesional treatment by curettage compared to wide resection for central low-grade chondrosarcoma (LGCS) of the long bones., Search Methods: We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 4), MEDLINE and Embase up to April 2018. We extended the search to include trials registries, reference lists of relevant articles and review articles. We also searched 'related articles' of included studies suggested by PubMed., Selection Criteria: In the absence of prospective randomised controlled trials (RCTs), we included retrospective comparative studies and case series that evaluated outcome of treatment of central LGCS of the long bones. The primary outcome was recurrence-free survival after a minimal follow-up of 24 months. Secondary outcomes were upgrading of tumour; functional outcome, as assessed by the Musculoskeletal Tumor Society (MSTS) score; and occurrence of complications., Data Collection and Analysis: We used standard methodological procedures recognised by Cochrane. We conducted a systematic literature search using several databases and contacted corresponding authors, appraised the evidence using the ROBINS-I risk of bias tool and GRADE, and performed a meta-analysis. If data extraction was not possible, we included studies in a narrative summary., Main Results: We included 18 studies, although we were only able to extract participant data from 14 studies that included a total of 511 participants; 419 participants were managed by intralesional treatment and 92 underwent a wide resection. We were not able to extract participant data from four studies, including 270 participants, and so we included them as a narrative summary only. The evidence was at high risk of performance, detection and reporting bias.Meta-analysis of data from 238 participants across seven studies demonstrated little or no difference in recurrence-free survival after intralesional treatment versus wide resection for central LGCS in the long bones (risk ratio (RR) 0.98; 95% confidence interval (CI) 0.92 to 1.04; very low-certainty evidence). MSTS scores were probably better after intralesional surgery (mean score 93%) versus resection (mean score 78%) with a mean difference of 12.69 (95% CI 2.82 to 22.55; P value < 0.001; 3 studies; 72 participants; low-certainty evidence). Major complications across six studies (203 participants) were lower in cases treated by intralesional treatment (5/125 cases) compared to those treated by wide resection (18/78 cases), with RR 0.23 (95% CI 0.10 to 0.55; low-certainty evidence). In four people (0.5% of total participants) a high-grade (grade 2 or dedifferentiated) tumour was found after a local recurrence. Two participants were treated with second surgery with no evidence of disease at their final follow-up and two participants (0.26% of total participants) died due to disease. Kaplan-Meier analysis of data from 115 individual participants across four studies demonstrated 96% recurrence-free survival after a maximum follow-up of 300 months after resection versus 94% recurrence-free survival after a maximum follow-up of 251 months after intralesional treatment (P value = 0.58; very low-certainty evidence). Local recurrence or metastases were not reported after 41 months in either treatment group., Authors' Conclusions: Only evidence of low- and very low-certainty was available for this review according to the GRADE system. Included studies were all retrospective in nature and at high risk of selection and attrition bias. Therefore, we could not determine whether wide resection is superior to intralesional treatment in terms of event-free survival and recurrence rates. However, functional outcome and complication rates are probably better after intralesional surgery compared to wide resection, although this is low-certainty evidence, considering the large effect size. Nevertheless, recurrence-free survival was excellent in both groups and a prospective RCT comparing intralesional treatment versus wide resection may be challenging for both practical and ethical reasons. Future research could instead focus on less invasive treatment strategies for these tumours by identifying predictors that help to stratify participants for surgical intervention or close observation.

Purpose: To determine the size of the ablation zone after radiofrequency ablation (RFA) of atypical cartilaginous bone tumors (ACT) using temperature-controlled 20 and 30 mm RFA straight non-cooled electrodes. Materials and methods: Sixteen patients with ACT in their long bones, who had undergone a single-session single-application CT-guided temperature-controlled RFA, were included retrospectively in the study. Tumors with a diameter of 10-25 mm were treated with 20 mm electrodes ( n  = 10), and tumors of 25-35 mm, with 30 mm electrodes ( n  = 6). The ablated zone was measured after three months on MRI images. Results: All the tumors were within the ablated zone on the 3-month follow-up MRI scan. The mean ablation time with the electrode, at a target temperature of 90 °C, was 7.6 minutes (range 6-10). The median of the largest ablation diameters, on applying the 20 and 30 mm electrodes, were 42 mm (IQR 8.5, range 30-51 mm) and 44.5 mm (IQR 4.5, range 42-63 mm), respectively. Conclusions: All the retrospectively viewed tumors in the long bones of ACT patients treated with RFA were completely ablated. The ablation zone diameters in the bones were larger than expected, when compared to other tissues, such as the liver.

Background and purpose - 18 F-fluorodeoxyglucose positron emission tomography (FDG-PET) can be used in the diagnostic work-up of a patient with suspected periprosthetic joint infection (PJI) but, due to a lack of accurate interpretation criteria, this technique is not routinely applied. Since the physiological uptake pattern of FDG around a joint prosthesis is not fully elucidated, we determined the physiological FDG uptake in non-infected total hip prostheses. Patients and methods - Patients treated with primary total hip arthroplasty (1995-2016) who underwent a FDG-PET/CT for an indication other than a suspected PJI were retrospectively evaluated. Scans were both visually and quantitatively analyzed. Semi-quantitative analysis was performed by calculating maximum and peak standardized uptake values (SUV max and SUV peak ) by volume of interests (VOIs) at 8 different locations around the prosthesis. Results - 58 scans from 30 patients were analyzed. In most hips, a diffuse heterogeneous uptake pattern around the prosthesis was observed (in 32/38 of the cemented prostheses, and in 16/20 of the uncemented prostheses) and most uptake was located around the neck of the prosthesis. The median SUV max in the cemented group was 2.66 (95% CI 2.51-3.10) and in the uncemented group 2.87 (CI 2.65-4.63) (Median difference = -0.36 [CI -1.2 to 0.34]). In uncemented prostheses, there was a positive correlation in time between the age of the prosthesis and the FDG uptake (r s = 0.63 [CI 0.26-0.84]). Interpretation - Our study provides key data to develop accurate interpretation criteria to differentiate between physiological uptake and infection in patients with a prosthetic joint.

Orthopedic oncologic surgery requires preservation of a functioning limb at the essence of achieving safe margins. With most bone sarcomas arising from the metaphyseal region, in close proximity to joints, joint-salvage surgery can be challenging. Intraoperative guidance techniques like computer-assisted surgery (CAS) and patient-specific instrumentation (PSI) could assist in achieving higher surgical accuracy. This study investigates the surgical accuracy of freehand, CAS- and PSI-assisted joint-preserving tumor resections and tests whether integration of CAS with PSI (CAS + PSI) can further improve accuracy. CT scans of 16 simulated tumors around the knee in four human cadavers were performed and imported into engineering software (MIMICS) for 3D planning of multiplanar joint-preserving resections. The planned resections were transferred to the navigation system and/or used for PSI design. Location accuracy (LA), entry and exit points of all 56 planes, and resection time were measured by postprocedural CT. Both CAS + PSI- and PSI-assisted techniques could reproduce planned resections with a mean LA of less than 2 mm. There was no statistical difference in LA between CAS + PSI and PSI resections ( p =0.92), but both CAS + PSI and PSI showed a significantly higher LA compared to CAS ( p =0.042 and p =0.034, respectively). PSI-assisted resections were faster compared to CAS + PSI ( p < 0.001) and CAS ( p < 0.001). Adding CAS to PSI did improve the exit points, however not significantly. In conclusion, PSI showed the best overall surgical accuracy and is fastest and easy to use. CAS could be used as an intraoperative quality control tool for PSI, and integration of CAS with PSI is possible but did not improve surgical accuracy. Both CAS and PSI seem complementary in improving surgical accuracy and are not mutually exclusive. Image-based techniques like CAS and PSI are superior over freehand resection. Surgeons should choose the technique most suitable based on the patient and tumor specifics.

Background: Actual and impending pathologic fractures of the femur are commonly treated with intramedullary nails because they provide immediate stabilization with a minimally invasive procedure and enable direct weightbearing. However, complications and revision surgery are prevalent, and despite common use, there is limited evidence identifying those factors that are associated with complications., Questions/purposes: Among patients treated with intramedullary nailing for femoral metastases, we asked the following questions: (1) What is the cumulative incidence of local complications? (2) What is the cumulative incidence of implant breakage and what factors are associated with implant breakage? (3) What is the cumulative incidence of revision surgery and what factors are associated with revision surgery?, Methods: Between January 2000 and December 2015, 245 patients in five centers were treated with intramedullary nails for actual and impending pathologic fractures of the femur caused by bone metastases. During that period, the general indications for intramedullary nailing of femoral metastases were impending fractures of the trochanter region and shaft and actual fractures of the trochanter region if sufficient bone stock remained; nails were used for lesions of the femoral shaft if they were large or if multiple lesions were present. Of those treated with intramedullary nails, 51% (117) were actual fractures and 49% (111) were impending fractures. A total of 60% (128) of this group were women; the mean age was 65 years (range, 29-93 years). After radiologic followup (at 4-8 weeks) with the orthopaedic surgeon, because of the palliative nature of these treatments, subsequent in-person followup was performed by the primary care provider on an as-needed basis (that is, as desired by the patient, without any scheduled visits with the orthopaedic surgeon) throughout each patient's remaining lifetime. However, there was close collaboration between the primary care providers and the orthopaedic team such that orthopaedic complications would be reported. A total of 67% (142 of 212) of the patients died before 1 year, and followup ranged from 0.1 to 175 months (mean, 14.4 months). Competing risk models were used to estimate the cumulative incidence of local complications (including persisting pain, tumor progression, and implant breakage), implant breakage separately, and revision surgery (defined as any reoperation involving the implant other than débridement with implant retention for infection). A cause-specific multivariate Cox regression model was used to estimate the association of factors (fracture type/preoperative radiotherapy and fracture type/use of cement) with implant breakage and revision, respectively., Results: Local complications occurred in 12% (28 of 228) of the patients and 6-month cumulative incidence was 8% (95% confidence interval [CI], 4.7-11.9). Implant breakage occurred in 8% (18 of 228) of the patients and 6-month cumulative incidence was 4% (95% CI, 1.4-6.5). Independent factors associated with increased risk of implant breakage were an actual (as opposed to impending) fracture (cause-specific hazard ratio [HR&#95;cs], 3.61; 95% CI, 1.23-10.53, p = 0.019) and previous radiotherapy (HR&#95;cs, 2.97; 95% CI, 1.13-7.82, p = 0.027). Revisions occurred in 5% (12 of 228) of the patients and 6-month cumulative incidence was 2.2% (95% CI, 0.3-4.1). The presence of an actual fracture was independently associated with a higher risk of revision (HR&#95;cs, 4.17; 95% CI, 0.08-0.82, p = 0.022), and use of cement was independently associated with a lower risk of revision (HR&#95;cs, 0.25; 95% CI, 1.20-14.53, p = 0.025)., Conclusions: The cumulative incidence of local complications, implant breakage, and revisions is low, mostly as a result of the short survival of patients. Based on these results, surgeons should consider use of cement in patients with intramedullary nails with actual fractures and closer followup of patients after actual fractures and preoperative radiotherapy. Future, prospective studies should further analyze the effects of adjuvant therapies and surgery-related factors on the risk of implant breakage and revisions., Level of Evidence: Level III, therapeutic study.

Background: Tenosynovial giant cell tumor (TGCT) is a rare, benign, monoarticular entity. Many case-series in adults are described, whereas TGCT is only incidentally reported in children. Therefore, its incidence rate and natural history in children are unknown., Questions/purposes: (1) How many cases have been reported of this condition, and what were their characteristics? (2) What is the standardized pediatric incidence rate for TGCT? (3) Is there a clinical difference in TGCT between children and adults? (4) What is the risk of recurrence after open resection in children compared with adults?, Methods: Data were derived from three sources: (1) a systematic review on TGCT in children, seeking sources published between 1990 and 2016, included 17 heterogeneous, small case-series; (2) the nationwide TGCT incidence study: the Dutch pediatric incidence rate was extracted from this nationwide study by including patients younger than 18 years of age. This registry-based study, in which eligible patients with TGCT were clinically verified, calculated Dutch incidence rates for localized and diffuse-type TGCT in a 5-year timeframe. Standardized pediatric incidence rates were obtained by using the direct method; (3) from our nationwide bone and soft tissue tumor data registry, a clinical data set was derived. Fifty-seven children with histologically proven TGCT of large joints, diagnosed and treated between 1995 and 2015, in all four tertiary sarcoma centers in The Netherlands, were included. These clinically collected data were compared with a retrospective database of 423 adults with TGCT. Chi-square test and independent t-test were used to compare children and adults for TGCT type, sex, localization, symptoms before diagnosis, first treatment, recurrent disease, followup status, duration of symptoms, and time to followup. The Kaplan-Meier method was used to evaluate recurrence-free survival at 2.5 years., Results: TGCT is seldom reported because only 76 pediatric patients (39 female), 29 localized, 38 diffuse, and nine unknown type, were identified from our systematic review. The standardized pediatric TGCT incidence rate of large joints was 2.42 and 1.09 per million person-years in localized and diffuse types, respectively. From our clinical data set, symptoms both in children and adults were swelling, pain, and limited ROM with a median time before diagnosis of 12 months (range, 1-72 months). With the numbers available, we did not observe differences in presentation between children and adults in terms of sex, symptoms before diagnosis, first treatment, recurrent disease, followup status, or median time to followup. The 2.5-year recurrence-free TGCT survival rate after open resection was not different with the numbers available between children and adults: 85% (95% confidence interval [CI], 67%-100%) versus 89% (95% CI, 83%-96%) in localized, respectively (p = 0.527) and 53% (95% CI, 35%-79%) versus 56% (95% CI, 49%-64%) in diffuse type, respectively (p = 0.691)., Conclusions: Although the incidence of pediatric TGCT is low, it should be considered in the differential diagnosis in children with chronic monoarticular joint effusions. Recurrent disease after surgical treatment of this orphan disease seems comparable between children and adults. With targeted therapies being developed, future research should define the most effective treatment strategies for this heterogeneous disease., Level of Evidence: Level III, therapeutic study.

Introduction: Fluoroscopy is currently the standard imaging modality for curettage of atypical cartilaginous tumors/chondrosarcoma grade 1 (ACT/CS1). Computer-assisted surgery (CAS) is a possible alternative, offering higher resolution imaging and continuous three-dimensional feedback without ionizing radiation use. CAS hypothetically makes curettage more accurate, thereby decreasing residue or recurrence rate. This study aims to compare CAS and fluoroscopy in curettage of ACT/CS1., Patients and Methods: A single center retrospective cohort study was performed. CAS and fluoroscopy were used in parallel. Included were patients who had curettage for ACT/CS1in the long bones, with a minimum follow-up of 24 months. Tumor volume was determined on pre-operative MRI scans. Outcome comprised local recurrence rates, residue rates, complications and procedure time., Results: Seventy-seven patients were included, 17 in the CAS cohort, 60 in the fluoroscopy cohort. Tumor volume was significantly larger in the CAS cohort (p = 0.04). There were no recurrences in either group. Residual tumor (2/17 vs. 7/60), complications did not differ significantly: fracture rate (3/17 vs. 6/60); nor did surgical time (1.26h vs. 1.34h)., Discussion: CAS curettage showed good oncologic results. Outcome was comparable to fluoroscopy, while not using ionizing radiation. There was no significant difference in surgical time. Residue rates can likely be decreased with specific software functions and surgical tools., Competing Interests: The authors have declared that no competing interests exist.

Introduction: Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are highly successful treatment modalities for advanced osteoarthritis. However, prolonged wound leakage after arthroplasty is linked to prosthetic joint infection (PJI), which is a potentially devastating complication. On the one hand, wound leakage is reported as a risk factor for PJI with a leaking wound acting as a porte d'entrée for micro-organisms. On the other hand, prolonged wound leakage can be a symptom of PJI. Literature addressing prolonged wound leakage is scarce, contradictory and of poor methodological quality. Hence, treatment of prolonged wound leakage varies considerably with both non-surgical and surgical treatment modalities. There is a definite need for evidence concerning the best way to treat prolonged wound leakage after joint arthroplasty., Methods and Analysis: A prospective nationwide randomised controlled trial will be conducted in 35 hospitals in the Netherlands. The goal is to include 388 patients with persistent wound leakage 9-10 days after THA or TKA. These patients will be randomly allocated to non-surgical treatment (pressure bandages, (bed) rest and wound care) or surgical treatment (debridement, antibiotics and implant retention (DAIR)). DAIR will also be performed on all non-surgically treated patients with persistent wound leakage at day 16-17 after index surgery, regardless of amount of wound leakage, other clinical parameters or C reactive protein. Clinical data are entered into a web-based database. Patients are asked to fill in questionnaires about disease-specific outcomes, quality of life and cost effectiveness at 3, 6 and 12 months after surgery. Primary outcome is the number of revision surgeries due to infection within a year of arthroplasty., Ethics and Dissemination: The Review Board of each participating hospital has approved the local feasibility. The results will be published in peer-reviewed scientific journals., Trial Registration Number: NTR5960;Pre-results., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Background: Persistent wound leakage after joint arthroplasty is a scantily investigated topic, despite the claimed relation with a higher risk of periprosthetic joint infection. This results in a lack of evidence-based clinical guidelines for the diagnosis and treatment of persistent wound leakage after joint arthroplasty. Without such guideline, clinical practice in orthopaedic hospitals varies widely. In preparation of a nationwide multicenter randomized controlled trial on the optimal treatment of persistent wound leakage, we evaluated current Dutch orthopaedic care for persistent wound leakage after joint arthroplasty. Methods: We conducted a questionnaire-based online survey among all 700 members of the Netherlands Orthopaedic Association, consisting of 23 questions on the definition, classification, diagnosis and treatment of persistent wound leakage after joint arthroplasty. Results: The questionnaire was completed by 127 respondents, representing 68% of the Dutch hospitals that perform orthopaedic surgery. The results showed wide variation in the classification, definition, diagnosis and treatment of persistent wound leakage among Dutch orthopaedic surgeons. 56.7% of the respondents used a protocol for diagnosis and treatment of persistent wound leakage, but only 26.8% utilized the protocol in every patient. Most respondents (59.1%) reported a maximum period of persistent wound leakage before starting non-surgical treatment of 3 to 7 days after index surgery and 44.1% of respondents reported a maximum period of wound leakage of 10 days before converting to surgical treatment. Conclusions: The wide variety in clinical practice underscores the importance of developing an evidence-based clinical guideline for the diagnosis and treatment of persistent wound leakage after joint arthroplasty. To this end, a nationwide multicenter randomized controlled trial will be conducted in the Netherlands, which may provide evidence on this important and poorly understood topic., Competing Interests: Competing Interests: The authors have declared that no competing interest exists.

Objective: Diagnosing bone infection in the diabetic foot is challenging and often requires several diagnostic procedures, including advanced imaging. We compared the diagnostic performances of MRI, radiolabeled white blood cell (WBC) scintigraphy (either with 99m Tc-hexamethylpropyleneamineoxime [HMPAO] or 111 In-oxine), and [ 18 F]fluorodeoxyglucose positron emission tomography ( 18 F-FDG-PET)/computed tomography., Research Design and Methods: We searched Medline and Embase as of August 2016 for studies of diagnostic tests on patients known or suspected to have diabetes and a foot infection. We performed a systematic review using criteria recommended by the Cochrane Review of a database that included prospective and retrospective diagnostic studies performed on patients with diabetes in whom there was a clinical suspicion of osteomyelitis of the foot. The preferred reference standard was bone biopsy and subsequent pathological (or microbiological) examination., Results: Our review found 6,649 articles; 3,894 in Medline and 2,755 in Embase. A total of 27 full articles and 2 posters was selected for inclusion in the analysis. The performance characteristics for the 18 F-FDG-PET were: sensitivity, 89%; specificity, 92%; diagnostic odds ratio (DOR), 95; positive likelihood ratio (LR), 11; and negative LR, 0.11. For WBC scan with 111 In-oxine, the values were: sensitivity, 92%; specificity, 75%; DOR, 34; positive LR, 3.6; and negative LR, 0.1. For WBC scan with 99m Tc-HMPAO, the values were: sensitivity, 91%; specificity, 92%; DOR, 118; positive LR, 12; and negative LR, 0.1. Finally, for MRI, the values were: sensitivity, 93%; specificity, 75%; DOR, 37; positive LR, 3.66, and negative LR, 0.10., Conclusions: The various modalities have similar sensitivity, but 18 F-FDG-PET and 99m Tc-HMPAO-labeled WBC scintigraphy offer the highest specificity. Larger prospective studies with a direct comparison among the different imaging techniques are required., (© 2017 by the American Diabetes Association.)

Background and Purpose: Osteoid osteoma is a benign skeletal tumour that accounts for 2-3% of all bone tumours. The male-to-female ratio is around 4:1 and it predominates in children and young adults. The most common symptom is pain, frequently at night-time. Historically the main form of treatment has been surgical excision. With the development of Radiofrequency Ablation (RFA) there is a percutaneus alternative. Success rates of RFA are lower but the main advantage is the minimal invasive character of the therapy and the low complication rate. As a result of the minimal invasiveness the hospitalization- and rehabilitation periods are relatively short. However, in current literature no values for accuracy and precision are known for the CT-guided positioning., Methods: Accuracy and precision of the needle position are determined for 86 procedures. Furthermore the population is divided into groups based on tumour diameter, location and procedure outcome., Results: The clinical success rate was 81.4%. In 79% of procedures complete ablation was achieved. Accuracy was 2.84 mm on average, precision was 2.94 mm. Accuracy was significantly lower in more profound lesions. Accuracy in tibia and fibula was significantly higher compared to the femur. No significant difference was found between different tumour diameters., Interpretation: The accuracy and precision found are considered good. Needle position is of major importance for procedure outcomes. The question however rises how the results of this therapy will turn out in treatment of larger tumours.

Background: Reconstruction of periacetabular defects after pelvic tumor resection ranks among the most challenging procedures in orthopaedic oncology, and reconstructive techniques are generally associated with dissatisfying mechanical and nonmechanical complication rates. In an attempt to reduce the risk of dislocation, aseptic loosening, and infection, we introduced the LUMiC ® prosthesis (implantcast, Buxtehude, Germany) in 2008. The LUMiC ® prosthesis is a modular device, built of a separate stem (hydroxyapatite-coated uncemented or cemented) and acetabular cup. The stem and cup are available in different sizes (the latter of which is also available with silver coating for infection prevention) and are equipped with sawteeth at the junction to allow for rotational adjustment of cup position after implantation of the stem. Whether this implant indeed is durable at short-term followup has not been evaluated., Questions/purposes: (1) What proportion of patients experience mechanical complications and what are the associated risk factors of periacetabular reconstruction with the LUMiC ® after pelvic tumor resection? (2) What proportion of patients experience nonmechanical complications and what are the associated risk factors of periacetabular reconstruction with the LUMiC ® after pelvic tumor resection? (3) What is the cumulative incidence of implant failure at 2 and 5 years and what are the mechanisms of reconstruction failure? (4) What is the functional outcome as assessed by Musculoskeletal Tumor Society (MSTS) score at final followup?, Methods: We performed a retrospective chart review of every patient in whom a LUMiC ® prosthesis was used to reconstruct a periacetabular defect after internal hemipelvectomy for a pelvic tumor from July 2008 to June 2014 in eight centers of orthopaedic oncology with a minimum followup of 24 months. Forty-seven patients (26 men [55%]) with a mean age of 50 years (range, 12-78 years) were included. At review, 32 patients (68%) were alive. The reverse Kaplan-Meier method was used to calculate median followup, which was equal to 3.9 years (95% confidence interval [CI], 3.4-4.3). During the period under study, our general indications for using this implant were reconstruction of periacetabular defects after pelvic tumor resections in which the medial ilium adjacent to the sacroiliac joint was preserved; alternative treatments included hip transposition and saddle or custom-made prostheses in some of the contributing centers; these were generally used when the medial ilium was involved in the tumorous process or if the LUMiC ® was not yet available in the specific country at that time. Conventional chondrosarcoma was the predominant diagnosis (n = 22 [47%]); five patients (11%) had osseous metastases of a distant carcinoma and three (6%) had multiple myeloma. Uncemented fixation (n = 43 [91%]) was preferred. Dual-mobility cups (n = 24 [51%]) were mainly used in case of a higher presumed risk of dislocation in the early period of our study; later, dual-mobility cups became the standard for the majority of the reconstructions. Silver-coated acetabular cups were used in 29 reconstructions (62%); because only the largest cup size was available with silver coating, its use depended on the cup size that was chosen. We used a competing risk model to estimate the cumulative incidence of implant failure., Results: Six patients (13%) had a single dislocation; four (9%) had recurrent dislocations. The risk of dislocation was lower in reconstructions with a dual-mobility cup (one of 24 [4%]) than in those without (nine of 23 [39%]) (hazard ratio, 0.11; 95% CI, 0.01-0.89; p = 0.038). Three patients (6%; one with a preceding structural allograft reconstruction, one with poor initial fixation as a result of an intraoperative fracture, and one with a cemented stem) had loosening and underwent revision. Infections occurred in 13 reconstructions (28%). Median duration of surgery was 6.5 hours (range, 4.0-13.6 hours) for patients with an infection and 5.3 hours (range, 2.8-9.9 hours) for those without (p = 0.060); blood loss was 2.3 L (range, 0.8-8.2 L) for patients with an infection and 1.5 L (range, 0.4-3.8 L) for those without (p = 0.039). The cumulative incidences of implant failure at 2 and 5 years were 2.1% (95% CI, 0-6.3) and 17.3% (95% CI, 0.7-33.9) for mechanical reasons and 6.4% (95% CI, 0-13.4) and 9.2% (95% CI, 0.5-17.9) for infection, respectively. Reasons for reconstruction failure were instability (n = 1 [2%]), loosening (n = 3 [6%]), and infection (n = 4 [9%]). Mean MSTS functional outcome score at followup was 70% (range, 33%-93%)., Conclusions: At short-term followup, the LUMiC ® prosthesis demonstrated a low frequency of mechanical complications and failure when used to reconstruct the acetabulum in patients who underwent major pelvic tumor resections, and we believe this is a useful reconstruction for periacetabular resections for tumor or failed prior reconstructions. Still, infection and dislocation are relatively common after these complex reconstructions. Dual-mobility articulation in our experience is associated with a lower risk of dislocation. Future, larger studies will need to further control for factors such as dual-mobility articulation and silver coating. We will continue to follow our patients over the longer term to ascertain the role of this implant in this setting., Level of Evidence: Level IV, therapeutic study.

Introduction: For chronic prosthetic joint infections (PJI), complete removal of the infected prosthesis is necessary in order to cure the infection. Unfortunately, a subgroup of patients is not able to undergo a revision surgery due to high surgical risk. Alternatively, these patients can be treated with antibiotic suppressive therapy (AST) to suppress the infection. Aim: To evaluate the efficacy and tolerability of AST. Methods: We retrospectively collected data (period 2009-2015) from patients with a PJI (of hip, knee or shoulder) who were treated with AST at the University Medical Center Groningen, the Netherlands. AST was defined as antibiotic treatment for PJI that was started after the usual 3 months of antibiotic treatment. The time of follow-up was defined from the time point AST was started. Treatment was considered as failed, when the patient still experienced joint pain, when surgical intervention (debridement, removal, arthrodesis or amputation) was needed to control the infection and/or when death occurred due to the infection. Results: We included 21 patients with a median age of 67 years (range 21 - 88) and with a median follow-up of 21 months (range 3 - 81). Coagulase negative staphylococci (CNS) (n=6), S. aureus (n=6) and polymicrobial flora (n=4) were the most frequently found causative pathogens. Most patients with CNS and S. aureus were treated with minocycline (67%) and clindamycin (83%) as AST, respectively. Overall, treatment was successful in 67% of patients. Failure was due to persistent joint pain (n=1), surgical intervention because of an uncontrolled infection (n=3), and death due the infection (n=3). We observed a treatment success of 90% in patients with a 'standard' prosthesis (n=11), compared to only 50% in patients with a tumor-prosthesis (n=10). Also, treatment was successful in 83% of patients with a CNS as causative microorganism for the infection, compared to 50% in patients with a S. aureus . Patients who failed on AST had a higher ESR in comparison to patients with a successful treatment (mean 73 ± 25SD versus 32 ± 19SD mm/hour (p = 0.007), respectively. 43% of patients experienced side effects and led to a switch of antibiotic treatment or a dose adjustment in almost all of these patients. Conclusions: Removal of the implant remains first choice in patients with chronic PJI. However, AST is a reasonable alternative treatment option in a subgroup of patients with a PJI who are no candidate for revision surgery, in particular in patients with a 'standard' prosthesis and/or CNS as the causative micro-organism., Competing Interests: Competing Interests: The authors have declared that no competing interest exists.

Objective: To investigate delay in diagnosis by both patients and doctors, and to evaluate its effect on outcomes of high-grade sarcoma of bone in a single-referral oncological center., Methods: Fifty-four patients with osteosarcoma, 29 with Ewing sarcoma and 19 with chondrosarcoma were enrolled in this retrospective study. Delay in diagnosis was defined as the period between initial clinical symptoms and histopathological diagnosis at our center. The delays were categorized as patient- or doctor-related. Short total delays were defined as <4 months; prolonged delays >4 months were assumed to have prognostic relevance., Results: Total delay in diagnosis was 688.0 days in patients with chondrosarcoma, which is significantly longer than the 163.3 days for osteosarcoma (P < 0.01) and 160.2 days for Ewing sarcoma (P < 0.01). Most doctor-related delays were at the pre-hospital stage, occurring at the general practitioner (GP)'s office. However, prolonged total delays (≥4 months) did not result in lower survival rates. Five-year-overall survival rates were 67.0% for osteosarcoma, 49.0% for Ewing sarcoma and 60.9% for chondrosarcoma. Survival was significantly lower for patients with metastatic disease for all three types of sarcoma., Conclusion: Prolonged delay in diagnosis does not result in lower survival. Metastatic disease has a pronounced effect on survival. Aggressive tumor behavior results in shorter delays. Minimizing GP-related delays could be achieved by adopting a lower threshold for obtaining plain radiographs at the pre-hospital stage., (© 2016 Chinese Orthopaedic Association and John Wiley & Sons Australia, Ltd.)

Background and Purpose: In orthopedic oncology, computer-assisted surgery (CAS) can be considered an alternative to fluoroscopy and direct measurement for orientation, planning, and margin control. However, only small case series reporting specific applications have been published. We therefore describe possible applications of CAS and report preliminary results in 130 procedures., Patients and Methods: We conducted a retrospective cohort study of all oncological CAS procedures in a single institution from November 2006 to March 2013. Mean follow-up time was 32 months. We categorized and analyzed 130 procedures for clinical parameters. The categories were image-based intralesional treatment, image-based resection, image-based resection and reconstruction, and imageless resection and reconstruction., Results: Application to intralesional treatment showed 1 inadequate curettage and 1 (other) recurrence in 63 cases. Image-based resections in 42 cases showed 40 R0 margins; 16 in 17 pelvic resections. Image-based reconstruction facilitated graft creation with a mean reconstruction accuracy of 0.9 mm in one case. Imageless CAS was helpful in resection planning and length- and joint line reconstruction for tumor prostheses., Interpretation: CAS is a promising new development. Preliminary results show a high number of R0 resections and low short-term recurrence rates for curettage.

Purpose: Evaluation of recurrences, complications and function at mid-term follow-up after curettage for sacral giant cell tumor (GCT)., Methods: We retrospectively studied all 26 patients treated for sacral GCT in the Netherlands (from 1990 to 2010). Median follow-up was 98 (6-229) months. All patients underwent intralesional excision, 21 with local adjuvants, 5 radiotherapy, 3 IFN-α, 1 bisphosphonates. Functional outcome was assessed using Musculoskeletal Tumor Society (MSTS) score. Statistics were performed with Kaplan-Meier, Cox regression, log rank and Mann-Whitney U., Results: Recurrence rate was 14/26 after median 13 (3-139) months and was highest after isolated curettage (4/5). Soft tissue masses >10 cm increased recurrence risk (HR = 3.3, 95 % CI = 0.81-13, p = 0.09). Complications were reported in 12/26 patients. MSTS was superior in patients without complications (27 vs. 21; p = 0.024)., Conclusion: Recurrence rate for sacral GCT was highest after isolated curettage, indicating that (local) adjuvant treatment is desired to obtain immediate local control. Complications were common and impaired function.

Biomaterials-associated infection incidence represents an increasing clinical challenge as more people gain access to medical device technologies worldwide and microbial resistance to current approaches mounts. Few reported antimicrobial approaches to implanted biomaterials ever get commercialized for physician use and patient benefit. This is not for lack of ideas since many thousands of claims to new approaches to antimicrobial efficacy are reported. Lack of translation of reported ideas into medical products approved for use, results from conflicting goals and purposes between the various participants involved in conception, validation, development, commercialization, safety and regulatory oversight, insurance reimbursement, and legal aspects of medical device innovation. The scientific causes, problems and impressive costs of the limiting clinical options for combating biomaterials-associated infection are well recognized. Demands for improved antimicrobial technologies constantly appear. Yet, the actual human, ethical and social costs and consequences of their occurrence are less articulated. Here, we describe several clinical cases of biomaterials-associated infections to illustrate the often-missing human elements of these infections. We identify the current societal forces at play in translating antimicrobial research concepts into clinical implant use and their often-orthogonal constituencies, missions and policies. We assert that in the current complex environment between researchers, funding agencies, physicians, patients, providers, producers, payers, regulatory agencies and litigators, opportunities for translatable successes are minimized under the various risks assumed in the translation process. This argues for an alternative approach to more effectively introduce new biomaterials and device technologies that can address the clinical issues by providing patients and medical practitioners new options for desperate clinical conditions ineffectively addressed by biomedical innovation., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Chondrosarcoma of the pelvis is difficult to treat due to the anatomical location and the high incidence of recurrence. Treatment is primarily surgical, and the surgical margins, based on MSTS criteria, have been shown to be predictive of disease recurrence and mortality. However, too-wide margins can decrease post-operative function. In the presented case, computer assisted surgery (CAS) was used to safely enable a joint-salvaging approach in a modified type 2/3 resection of a grade 2 chondrosarcoma of the os ischium and os pubis. The CAS navigation was vital to achieving the desired safe margins. The current follow-up period is 3.5 years, and the patient is disease-free, with no local recurrences or metastases having been detected. Post-operative function is excellent, with good MSTS and SF36 scores. This outcome is a good example of the value of CAS in certain cases.

Introduction: The duration of symptoms preceding a definitive diagnosis of osteosarcoma is quite long. Pathological radiological signs are often evident by the time of diagnosis. Although several case reports have been published on osteosarcoma of the femur, to the best of our knowledge this report is the first one with such an unusual clinical course., Case Presentation: We describe the case of a 58-year-old Caucasian man who presented with a femoral shaft fracture. Two years post-trauma osteosarcoma in the ipsilateral distal femur was diagnosed. Was it coincidence? We think that the history of the trauma is crucial to answering this question., Conclusion: This case report underlines the need to keep up awareness of pathological fractures in emergency medicine and trauma surgery. When radiographs do not raise any suspicion but the history of trauma or the physical examination does, we recommend further radiological and/or histological diagnostic examinations.

Background: Enchondromatosis is characterized by the presence of multiple benign cartilage lesions in bone. While Ollier disease is typified by multiple enchondromas, in Maffucci syndrome these are associated with hemangiomas. Studies evaluating the predictive value of clinical symptoms for development of secondary chondrosarcoma and prognosis are lacking. This multi-institute study evaluates the clinical characteristics of patients, to get better insight on behavior and prognosis of these diseases., Method: A retrospective study was conducted using clinical data of 144 Ollier and 17 Maffucci patients from 13 European centers and one national databank supplied by members of the European Musculoskeletal Oncology Society., Results: Patients had multiple enchondromas in the hands and feet only (group I, 18%), in long bones including scapula and pelvis only (group II, 39%), and in both small and long/flat bones (group III, 43%), respectively. The overall incidence of chondrosarcoma thus far is 40%. In group I, only 4 patients (15%) developed chondrosarcoma, in contrast to 27 patients (43%) in group II and 26 patients (46%) in group III, respectively. The risk of developing chondrosarcoma is increased when enchondromas are located in the pelvis (odds ratio, 3.8; p = 0.00l)., Conclusions: Overall incidence of development of chondrosarcoma is 40%, but may, due to age-dependency, increase when considered as a lifelong risk. Patients with enchondromas located in long bones or axial skeleton, especially the pelvis, have a seriously increased risk of developing chondrosarcoma, and are identified as the population that needs regular screening on early detection of malignant transformation.