Elevated cobalt levels in metal-on-polyethylene knee megaprostheses: a prospective 1-year cohort study of 56 patients with hip and knee megaprostheses.

BACKGROUND AND PURPOSE: Concerns have emerged regarding elevated levels of cobalt and chromium in patients with metal-on-metal megaprostheses. This prospective study aims to identify systemic cobalt and chromium levels in metal-on-polyethylene knee and hip megaprostheses and their associations with other factors. METHODS: 56 patients underwent knee or hip megaprosthesis surgery at 2 sarcoma centers. Serum cobalt and chromium levels were measured preoperatively and thrice within the first year using inductively coupled plasma mass spectrometry. RESULTS: A statistically significant difference in serum cobalt levels (1.4 ppb; 95% confidence interval [CI] 0.0-3.3) was observed 1 year after knee megaprosthesis surgery compared with preoperative levels. In contrast no difference in chromium levels was observed after 1 year compared with preoperative levels (0.05 ppb; CI 0.0-0.8). An association between younger age, higher eGFR, and increased cobalt levels was observed. No significant correlations were found between ion levels and resection length or the number of modular connections. CONCLUSION: We found elevated serum ion levels in metal-on-polyethylene knee megaprostheses in contrast to metal-on-polyethylene hip megaprostheses. Furthermore, a positive correlation between cobalt and chromium levels, and between cobalt and eGFR was identified, along with a negative correlation between cobalt and age. This study highlights the importance of monitoring systemic cobalt and chromium levels in patients with megaprostheses.

LTX-315 and adoptive cell therapy using tumor-infiltrating lymphocytes generate tumor specific T cells in patients with metastatic soft tissue sarcoma.

LTX-315 is an oncolytic peptide that elicits both local and systemic immune responses upon intratumoral injection. In the present pilot trial, we treated patients with metastatic soft tissue sarcoma with the combination of LTX-315 and adoptive T-cell therapy using in vitro expanded tumor-infiltrating lymphocytes. Six heavily pretreated patients were included in the trial and treated with LTX-315 of which four patients proceeded to adoptive T-cell therapy. Overall, the treatment was considered safe with only expected and manageable toxicity. The best overall clinical response was stable disease for 208 days, and in this patient, we detected tumor-reactive T cells in the blood that lasted until disease progression. In three patients T-cell reactivity against in silico predicted neoantigens was demonstrated. Additionally, de novo T-cell clones were generated and expanded in the blood following LTX-315 injections. In conclusion, this pilot study provides proof that it is feasible to combine LTX-315 and adoptive T-cell therapy, and that this treatment can induce systemic immune responses that resulted in stabilization of the disease in sarcoma patients with otherwise progressive disease. Further optimization of the treatment protocol is warranted to increase clinical activity. ClinicalTrials.gov Identifier: NCT03725605.

Protocol Article: A Cross-Sectional Evaluation of Children's Feet and Lower Extremities.

BACKGROUND: The health of children's lower extremities and feet is a focus area for caregivers and healthcare professionals such as doctors, school nurses, and podiatrists. Our study aims to investigate the general health status of Danish children's lower extremities and feet to identify anthropometric parameters that might be preconditions for pain and evaluate for foot diseases and whether they are associated with pain intensity and location, three-dimensional foot dimensions and foot pressure mapping, shoe dimensions, types and intensity of sports activity, quality of life, and foot health. The aim is that we will be able to identify parameters pre-dispositioning for pain, thus providing recommendations for sports activities in relation to the anthropometric conditions of a child as a potential preventive measure for pain. This analysis will be stratified by socioeconomic status on a group level, and this perspective will be able to provide preventative recommendations to prevent pain. METHODS: This study is a cross-sectional examination of a thousand children in the first, fifth, and ninth grades in randomized selected Danish primary schools. We will perform a clinical examination of the lower extremities and feet for misalignments, deformities, and diseases as well as rotational status and range of motion. Moreover, we will evaluate their pain levels, sports activities, three-dimensional foot dimensions, plantar pressure, footwear, and patient-related outcome measures (PROMs) for foot health and quality of life. RESULTS: We aim to provide an anthropometrical overview of the lower extremities and feet in children. The obtained basic understanding of healthy normal material in children will be analyzed for its relationships with pain level, sports activities, and socioeconomic status on a group level. This could potentially provide us with an understanding of the factors that impact lower extremity and foot diseases in children. In conclusion, examining children's lower extremities and feet in Danish primary schools is a step toward identifying areas of improvement in self-care and shoe fitting, mapping podiatry-related needs of care in children's feet, and providing parental recommendations for preventive actions on shoe fitting and the choice and intensity of sports activity concerning pain. CONCLUSIONS: The tenet of this study is a long-term follow-up to evaluate the long-term socioeconomic course on a group level, foot status, and sports activity, using patient-related outcome measures evaluating quality of life and other lifestyle factors such as emotional functioning, social functioning and interaction, and school functioning. Potentially, this will improve children's quality of life and prevent future diseases.

Biomechanical Variability and Usability of a Novel Customizable Fracture Fixation Technique.

A novel in situ customizable osteosynthesis technique, Bonevolent™ AdhFix, demonstrates promising biomechanical properties under the expertise of a single trained operator. This study assesses inter- and intra-surgeon biomechanical variability and usability of the AdhFix osteosynthesis platform. Six surgeons conducted ten osteosyntheses on a synthetic bone fracture model after reviewing an instruction manual and completing one supervised osteosynthesis. Samples underwent 4-point bending tests at a quasi-static loading rate, and the maximum bending moment (BM), bending stiffness (BS), and AdhFix cross-sectional area (CSA: mm²) were evaluated. All constructs exhibited a consistent appearance and were suitable for biomechanical testing. The mean BM was 2.64 ± 0.57 Nm, and the mean BS was 4.35 ± 0.44 Nm/mm. Statistically significant differences were observed among the six surgeons in BM (p < 0.001) and BS (p = 0.004). Throughout ten trials, only one surgeon demonstrated a significant improvement in BM (p < 0.025), and another showed a significant improvement in BS (p < 0.01). A larger CSA corresponded to a statistically significantly higher value for BM (p < 0.001) but not for BS (p = 0.594). In conclusion, this study found consistent biomechanical stability both across and within the surgeons included, suggesting that the AdhFix osteosynthesis platform can be learned and applied with minimal training and, therefore, might be a clinically viable fracture fixation technique. The variability in BM and BS observed is not expected to have a clinical impact, but future clinical studies are warranted.

Sclerotherapy as a primary or salvage procedure for aneurysmal bone cysts: A single-center experience.

BACKGROUND: Aneurysmal bone cysts (ABC) are benign cystic bone tumors of an osteolytic and locally aggressive nature. As an alternative to the primary treatment of choice, which consists of curettage with bone grafting, alternative treatment methods with promising results have been described. At our department, we have, in recent years, used percutaneous sclerotherapy with polidocanol. The objective of this study was to identify the healing rate and safety of sclerotherapy with polidocanol. AIM: To identify the efficacy and safety of sclerotherapy with polidocanol in primary and recurrent ABC. METHODS: Twenty-two consecutive patients (median age 12.5 years; range 1-27) with 23 ABCs treated with sclerotherapy with polidocanol from 2016-2021 were included retrospectively. Eleven patients (48%) had undergone different forms of previous treatment with recurrence. Under general anesthesia and fluoroscopic guidance, repeated percutaneous injections of 4mg polidocanol/kg body weight were performed. Through review of the electronic medical records, the following were identified: healing and recurrence rate, number of treatments, gender, age, comorbidity, location of the tumor and side effects / complications, as well as any previous surgery for ABC. The median length of radiographic follow-up was 19.5 mo. RESULTS: All ABCs except one (96%) showed healing or stable disease after a median of 4 (range 1-8) injections. Complete clinical and radiographic healing was observed in 16 cysts (70%), while partial radiographic healing with resolution of pain was seen in 6 cases (26%) and considered as stable disease. The cyst that failed to heal had previously undergone curettage twice with recurrence. One patient with a large pelvic ABC experienced, right after two injections, a sudden drop in blood pressure, which could quickly be reversed. One patient with a juxtaphyseal ABC in the femoral neck showed a minor limb length discrepancy because of deformity. Beyond that, no complications were observed. CONCLUSION: Percutaneous sclerotherapy with polidocanol appears to be a safe alternative for treatment of aneurysmal bone cysts. In our series of both primary and recurrent cysts, it showed the ability to achieve healing or stable disease in 22 of 23 cases (96%). Further studies are needed to decide if this provides a long-lasting effect.

Plate-assisted bone-segment transport in the femur with 2 internal lengthening nails: a technical note and a case report.

A novel technique to resolve large bone defects, using 2 internal lengthening nails (ILNs), one antegrade and one retro-grade, aligned in a custom-made tube is presented. A 28-year-old, healthy, asymptomatic male presented with a slowly growing mass in the left femur.

Tibial Component Undersizing Is Related to High Degrees of Implant Migration Following Cementless Total Knee Arthroplasty: A Study of Radiostereometric Analysis Data for 111 Patients with 2-Year Follow-up.

Radiostereometric analysis (RSA) studies have shown that the continuous migration of tibial components is predictive of aseptic loosening following total knee arthroplasty (TKA). In the present study, we investigated whether accurate sizing and placement of tibial components are related to the degree of implant migration as measured with use of RSA. Methods: A total of 111 patients who underwent TKA surgery with a cementless tibial component were followed for a period of 2 years postoperatively, during which implant migration was assessed with use of RSA. RSA was performed within 7 days postoperatively and after 3, 6, 12, and 24 months. Postoperative radiographs were evaluated for component size and placement in the tibia. The evaluations were performed by experienced knee surgeons who were blinded to the migration data and clinical outcomes. A multivariable linear regression analysis was conducted. Results: Continuous implant migration (i.e., migration occurring between 12 and 24 months postoperatively) had a negative association with tibial component size (coefficient [B], -0.2; 95% confidence interval [CI], -0.33 to -0.08). Subsidence was associated with the absence of posterior cortical bone support (B, -0.7; 95% CI, -1.09 to -0.28), the absence of lateral cortical bone support (B, 0.8; 95% CI, 0.29 to 1.37), frontal-plane varus malalignment (B, 0.6; 95% CI, 0.12 to 1.16), and component undersizing (B, -0.4; 95% CI, -0.06 to -0.68). Posterior tilt was associated only with undersizing (B, 0.6; 95% CI, 0.27 to 1.11). Conclusions: Undersized cementless tibial components are at a higher risk for poor fixation with continuous migration following TKA. Therefore, a higher risk of aseptic loosening should be expected. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Biomechanical performance of a novel light-curable bone fixation technique.

Traumatic bone fractures are often debilitating injuries that may require surgical fixation to ensure sufficient healing. Currently, the most frequently used osteosynthesis materials are metal-based; however, in certain cases, such as complex comminuted osteoporotic fractures, they may not provide the best solution due to their rigid and non-customizable nature. In phalanx fractures in particular, metal plates have been shown to induce joint stiffness and soft tissue adhesions. A new osteosynthesis method using a light curable polymer composite has been developed. This method has demonstrated itself to be a versatile solution that can be shaped by surgeons in situ and has been shown to induce no soft tissue adhesions. In this study, the biomechanical performance of AdhFix was compared to conventional metal plates. The osteosyntheses were tested in seven different groups with varying loading modality (bending and torsion), osteotomy gap size, and fixation type and size in a sheep phalanx model. AdhFix demonstrated statistically higher stiffnesses in torsion (64.64 ± 9.27 and 114.08 ± 20.98 Nmm/° vs. 33.88 ± 3.10 Nmm/°) and in reduced fractures in bending (13.70 ± 2.75 Nm/mm vs. 8.69 ± 1.16 Nmm/°), while the metal plates were stiffer in unreduced fractures (7.44 ± 1.75 Nm/mm vs. 2.70 ± 0.72 Nmm/°). The metal plates withstood equivalent or significantly higher torques in torsion (534.28 ± 25.74 Nmm vs. 614.10 ± 118.44 and 414.82 ± 70.98 Nmm) and significantly higher bending moments (19.51 ± 2.24 and 22.72 ± 2.68 Nm vs. 5.38 ± 0.73 and 1.22 ± 0.30 Nm). This study illustrated that the AdhFix platform is a viable, customizable solution that is comparable to the mechanical properties of traditional metal plates within the range of physiological loading values reported in literature.

Dislocation rate after hip arthroplasty due to metastatic bone disease: a retrospective cohort study evaluating the postoperative dislocation risk across different articulating solutions.

BACKGROUND AND PURPOSE: Joint stability after hip replacement (HR) in patients with metastatic bone disease (MBD) is of special importance. Dislocation is the second leading cause of implant revision in HR, while survival after MBD surgery is poor with an expected 1-year survival of around 40%. As few studies have investigated the dislocation risk across different articulation solutions in MBD, we conducted a retrospective study on primary HR for patients with MBD treated in our department. PATIENTS AND METHODS: The primary outcome is the 1-year cumulative incidence of dislocation. We included patients with MBD who received HR at our department in 2003-2019. We excluded patients with partial pelvic reconstruction, total femoral replacement, and revision surgery. We assessed the incidence of dislocation with competing risk analysis with death and implant removal as competing risks. RESULTS: We included 471 patients. Median follow-up was 6.5 months. The patients received 248 regular total hip arthroplasties (THAs), 117 hemiarthroplasties, 70 constrained liners, and 36 dual mobility liners. Major bone resection (MBR), defined as resection below the lesser trochanter, was performed in 63%. The overall 1-year cumulative incidence of dislocation was 6.2% (95% CI 4.0-8.3). Dislocation stratified by articulating surface was 6.9% (CI 3.7-10) for regular THA, 6.8% (CI 2.3-11) for hemiarthroplasty, 2.9% (CI 0.0-6.8) for constrained liner, and 5.6% (CI 0.0-13) for dual mobility liners. There was no significant difference between patients with and without MBR (p = 0.5). CONCLUSION: The 1-year cumulative incidence of dislocation is 6.2% in patients with MBD. Further studies are needed to determine any real benefits of specific articulations on the risk of postoperative dislocation in patients with MBD.

Fully constrained acetabular liner vs. dual mobility hip joint in the surgical treatment of metastatic bone disease of the hip: study protocol for a randomized, open-label, two-arm, non-inferiority trial evaluating the post-operative hip dislocation rate.

BACKGROUND: Patients receiving total hip arthroplasty (THA) due to metastatic bone disease of the hip (MBD) are at an increased risk of post-operative joint dislocation compared to other populations. Different joint solutions have been developed with the purpose of reducing the dislocation risk compared to regular THAs. One of these solutions, the constrained liner (CL), has been used increasingly at our department in recent years. This design, however, is prone to polyethylene wear and higher revision rates. An alternative is the dual mobility cup (DM), which has been shown to reduce the risk of dislocation in other high-risk populations. Few studies have investigated DM for THA due to MBD, and no studies have directly compared these two treatments in this population. We therefore decided to conduct a trial to investigate whether DM is non-inferior to CL regarding the post-operative joint dislocation risk in patients receiving THA due to MBD. MATERIALS AND METHODS: This study is a single-center, randomized, open-label, two-arm, non-inferiority trial. We will include 146 patients with MBD of the hip who are planned for THA at the Department of Orthopedic Surgery, Rigshospitalet. Patients with previous osteosynthesis or endoprosthetic surgery of the afflicted hip, or who are planned to receive partial pelvic reconstruction or total femoral replacement, will be excluded. Patients will be stratified by whether subtrochanteric bone resection will be performed and allocated to either CL or DM in a 1:1 ratio. The primary outcome is the 6 months post-operative joint dislocation rate. Secondary outcomes include overall survival, implant survival, the rate of other surgical- and post-operative complications, and quality of life and functional outcome scores. DISCUSSION: This study is designed to investigate whether DM is non-inferior to CL regarding the risk of post-operative dislocation in patients receiving THA due to MBD. To our knowledge, this trial is the first of its kind. Knowledge gained from this trial will help guide surgeons in choosing a joint solution that minimizes the risk of dislocation and, ultimately, reduces the need for repeat surgeries in this patient population. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05461313. Registered on July 15 2022. This trial is reported according to the items in the WHO Trial Registration Data Set (Version 1.3.1).

Total calcaneal reconstruction using a massive bone allograft and a distally pedicled osteocutaneous fibula flap: A novel technique to prevent amputation after calcaneal malignancy.

In patients with primary calcaneal malignancies, such as Ewing's sarcoma, radical treatment with amputation of the foot can result in serious functional impairment and chronic pain. Total calcanectomy followed by the reconstruction of the calcaneal defect offers an alternative treatment to amputation. Capanna et al. described a technique for successfully reconstructing long limb segmental bone defects using a free fibula flap placed within the intramedullary canal of an allograft. We present both a review of the literature on calcaneal reconstruction and describe how the principles of Capanna can be adapted to reconstruct the calcaneus. Total calcanectomy due to Ewing's sarcoma and the subsequent application of this novel reconstructive technique was performed in two young patients aged 5 and 16 years. The reconstruction was achieved by inserting a distally pedicled osteocutaneous fibula flap within the reamed canal of an allograft and placing the composite in the calcaneal defect. Reconstruction was successful with complete bone union between the allograft and the adjacent bone. There were no fractures or infections and both flaps survived. Functional outcome was assessed with a physiotherapist at a follow-up period of 2 years postoperatively, showing near-normal ambulance. This novel technique proved excellent as a limb salvage procedure, avoiding amputation, and offering a satisfactory oncological and functional outcome.

Survival Prediction in Patients Treated Surgically for Metastases of the Appendicular Skeleton-An External Validation of 2013-SPRING Model.

INTRODUCTION: The aim of this study was to externally validate the 2013-SPRING model, a survival prediction tool for patients treated surgically for bone metastases in a retrospective patient cohort from a single institution. Moreover, subgroup analyses on patients treated with (A) endoprostheses or (B) osteosynthesis, as well as (C) upper limb and (D) lower limb metastases, were performed. METHODS: Altogether, 303 cancer patients (mean age: 67.6 ± 11.1 years; 140 males (46.2%)) with bone metastases to the extremities, treated surgically between March 2000 and June 2018 at a single tertiary sarcoma centre, were retrospectively included. Median follow-up amounted to 6.3 (interquartile range (IQR): 2.3-21.8) months, with all patients followed-up for at least one year or until death. The 2013-SPRING model was applied to assess the prognostication accuracy at 3, 6 and 12 months. Models were validated with area under the curve receiver operator characteristic (AUC ROC; the higher the better), as well as Brier score. RESULTS: Of the 303 patients, 141 had been treated with osteosynthesis (46.5%), and the remaining 162 patients with endoprosthesis (53.5%). Sixty-five (21.5%) metastases were located in the upper limbs, and two hundred and thirty-eight (78.5%) in the lower limbs. Using the 2013-SPRING model for the entire cohort, the accuracy of risk of death prediction at 3, 6 and 12 months, determined by the AUC ROC, was 0.782 (95% CI: 0.729-0.843), 0.810 (95% CI: 0.763-0.858) and 0.802 (95% CI: 0.751-0.854), respectively. Corresponding Brier scores were 0.170, 0.178 and 0.169 at 3, 6 and 12 months. In the subgroup analyses, predictive accuracy of the 2013-SPRING model was likewise encouraging, albeit being slightly higher in the osteosynthesis subgroup as compared with the endoprosthesis subgroup, and also higher in the upper limb in comparison to the lower limb metastasis subgroup. CONCLUSIONS: The current validation study of the 2013-SPRING model shows that this model is clinically relevant to use in an external cohort, also after stratification for surgical procedure and metastasis location.

Effect of negative pressure wound therapy after surgical removal of deep-seated high-malignant soft tissue sarcomas of the extremities and trunk wall-study protocol for a randomized controlled trial.

BACKGROUND: Sarcomas are a heterogeneous group of rare malignant tumors of mesenchymal origin in the musculoskeletal system. The main treatment is surgery often supplemented with pre-or postoperative radiotherapy. A retrospective study by Bedi et al. indicated that negative pressure wound therapy (NPWT) reduced the risk of postoperative wound complications in patients treated with preoperative radiation followed by surgical tumor removal of lower extremity soft tissue sarcomas (STS), and the use of NPWT was not associated with an increased risk of local recurrence. Previous studies have shown that NPWT can reduce postoperative complications. STS surgeries are a high-risk procedure concerning wound complications. METHODS: Non-blinded single-center randomized controlled trial comparing NPWT versus conventional wound dressing and postoperative wound complications after surgical removal of deep-seated high-malignant STS of the extremities or trunk wall Sample-size calculation: 154 STS patients (80% risk of avoiding type II error, 5% risk of type I error, and an 80% wound complication risk) Block randomization of 8 into: Group A: Conventional wound dressing Group B: NPWT (PREVENA PLUS™ Incision Management System) Inclusion criteria: Surgery for a deep-seated STS of an extremity or the trunk wall Exclusion criteria: Age < 18 years, plastic surgery, low malignant/borderline STS, chemotherapy, preoperative radiotherapy, allergic/hypersensitive to acrylic adhesives or silver, unwilling/unable to provide informed consent, metastatic disease, and ischemic surgeries Primary study endpoints were set as major wound complications defined by O'Sullivan et al. as a secondary surgery under anesthesia for wound repairs and wound management without secondary surgery within 4 months postoperatively. Secondary study endpoints among others are Musculoskeletal Tumor Society Score (MSTS), Toronto Extremity Salvage Score (TESS), and European Quality of Life - 5 Dimensions (EQ-5D). Approval from the Scientific Ethical Committee and the Data Protection Agency has been obtained, and the study is registered at clinicaltrial.gov . This study did not apply for external funding. DISCUSSION: Many new medical devices and technical solutions are currently being introduced, and even though some documentation regarding the use of NPWT, e.g., in joint replacement surgery exist, it is also important to seek documentation for this treatment principle in STS surgery. TRIAL REGISTRATION: Registered at ClinicalTrials.gov NCT04960332 and approved on 11 July 2021.

Evaluation of tumor-prostheses over time: Complications, functional outcome, and comparative statistical analysis after resection and reconstruction in orthopedic oncologic conditions in the lower extremities.

Objectives: Previous multicenter studies report variable outcomes and failure rates after tumor-prosthetic reconstructions. The purpose of this study was (1) to evaluate implant survival, limb survival, and functional outcome in a cohort of patients who underwent resection of primary malignancies or aggressive benign bone tumors and reconstruction with modern tumor-prostheses in the lower extremities and (2) to provide comparison to a historical cohort on previous generations of tumor-prostheses from the same center. Methods: A longitudinal retrospective single-center study of 72 consecutive patients (F/M = 30/42), mean age = 44 (range = 7-84) years with bone, soft tissue sarcoma adjacent to bone (n = 69), and aggressive benign bone tumors (n = 3) having surgery between 2006 and 2016 with bone resection and reconstruction with tumor-prostheses were compared to a historical cohort from1985 to 2005. Revisions were classified as major and minor revisions. Causes of failure were classified according to the Henderson classification. Fine and Gray competing risk analysis was used for assessing cumulative incidence for implant revision and limb amputation. Functional outcome was evaluated with Musculoskeletal Tumor Society Score system. Results: Forty-seven patients were alive at the end of the study. Mean follow-up was 6 years (range = 2-13 years). Ten-year cumulative risk of major revision was 18% (95% confidence interval = 9%-28%). Deep infection and recurrence of tumor caused most revisions in modern tumor-prostheses. Ten-year cumulative incidence of limb amputation was 11% (95% confidence interval = 3%-18%). According to the Henderson classification, the overall predominant failure mode was non-mechanical (n = 20, 51%). Mean Musculoskeletal Tumor Society Score was 20 (67%) (range = 0-30). Conclusion: A minimum of 2 years follow-up with modern modular tumor-prostheses demonstrated a relatively low risk of implant failure and amputation and also an acceptable functional outcome. No statistical difference of, implant survival, limb survival and functional outcome between tumor-prostheses over two time periods was observed, possibly explained by Type 2 error.

Surgical Treatment of Metastatic Bone Disease in the Appendicular Skeleton: A Population-Based Study.

Background: Population-based studies of patients with bone metastases in the appendicular skeleton (aBM) requiring surgery for complete or impending fracture are rare. In this epidemiologically-based observational study we created a large population-based cohort of patients treated for aBM, aiming to: (1) monitor possible time-related changes of the incidence of surgical treatment of aBM-lesions, (2) examine differences in the population and care of patients treated at different treatment centers and (3) examine if findings from a previous pilot study regarding absence of a suitable biopsy of the lesions representing debut of cancer or a relapse has improved the awareness of aBM and hereby increased the focus on regular tumor biopsies and follow-up imaging of cancer patients. Methods: We examined a population-based cohort consisting of all patients treated for aBM 2014−2019. Procedures were performed at five secondary surgical centers (SSC) or one tertiary referral Musculoskeletal Tumor Center (MTC). Patients were followed until end of study (30 September 2021) or death. No patients were lost to follow-up. Results: Four-hundred-fifty-seven patients (493 primary aBM-lesions, 482 procedures) were included. Annual incidence of aBM-surgery was 46 aBM-lesions/million. MTC-patients had a significant better preoperative status than SSC-patients considering factors known for survival. Patients with complete fracture experienced longer surgical delay when treated at MTC compared to SSC: 4 (1−9) and 1 (1−3) days (p < 0.001), respectively. Overall survival for the entire cohort was 37% and 11% at 1 and 5 years (MTC and SSC 1 and 5 year respectively: 44% and 15% vs. 29% and 5%, p < 0.001). In patients with debut or relapse of cancer, 8% and 9% had insufficient biopsies, and 21% and 12% had no biopsy, respectively. Comparison showed no change over time. Conclusions: The current study highlights the low awareness on treating aBM at SSC and emphasizes the importance of caution in interpretation of studies not representing an entire population, thus introducing selection bias.

[Diagnostics and treatment of lipomas].

In this case report, a woman of 55 years suddenly developed foot pain and swelling 13 years after treatment for breast cancer. X-ray was found to be normal, and the symptoms were in three months interpreted as ligamentous sprains. Due to persistent pain and functional impairment together with a renewed X-ray suspicious for malignancy, an MRI scan was performed and signs of malignancy were confirmed. A biopsy from talus showed metastasis from a breast carcinoma, and the patient was treated with an amputation.

Clinical outcome after surgery on schwannomas in the extremities.

BACKGROUND: Schwannoma is a benign, encapsulated and slowly growing tumor originating from Schwann cells and is rarely seen in the peripheral nerve system. Typical symptoms are soreness, radiating pain and sensory loss combined with a soft tissue mass. AIM: To evaluate pre- and postoperative symptoms in patients operated for schwannomas in the extremities and investigate the rate of malignant transformation. METHODS: In this single center retrospective study design, all patients who had surgery for a benign schwannoma in the extremities from May 1997 to January 2018 were included. The location of the tumor in the extremities was divided into five groups; forearm, arm, shoulder, thigh and leg including foot. The locations of the tumor in the nerves were also categorized as either; proximal, distal, minor or major nerve. During the pre- and postoperative clinical evaluation, symptoms were classified as paresthesia, local pain, radiating pain, swelling, impairment of mobility/strength and asymptomatic tumors that were found incidentally (with magnetic resonance imaging). The patients were evaluated after surgery using the following categories: Asymptomatic or symptomatic patients (radiating and/or local pain) and those with complications. The follow up period was from the time of surgery until last examination of the particular physician. Multivariate logistic regression analysis was performed to identify independent prognostic factors for postoperative significant symptoms at follow-up. RESULTS: We identified 858 cases from the institutional pathology register. We excluded cases with duplicate diagnoses (n = 407), pathology not including schwannomas (n = 157), lesions involving the torso, spine and neck (n = 150) leaving 144 patients for further analysis. In this group 99 patients underwent surgery and there were five complications recorded: 2 infections (treated with antibiotics) and 3 nerve palsies (2 involving the radial nerve and one involving the median nerve) that recovered spontaneously. At the end of follow-up, 1.4 mo (range 0.5-76) postoperatively, we recorded a post-operative decrease in clinical symptoms: Local pain 76% (6/25), radiating pain 97% (2/45), swelling 20% (8/10). Symptoms of paresthesia increased by 2.8% (37/36) and there was no change in motor weakness before and after surgery 1% (1/1). Multivariate analysis showed that tumors located within minor nerves had a significantly higher prevalence of postoperative symptoms compared with tumors in major nerves (odds ratio: 2.63; confidence intervals: 1.22-6.42, P = 0.029). One patient with schwannoma diagnosed by needle biopsy was diagnosed to have malignant transformation diagnosed in the surgically removed tumor. No local recurrences were reported. CONCLUSION: Surgery of schwannomas can be conducted with low risk of postoperative complications, acceptable decrease in clinical symptoms and risk of malignant transformation is low.

Current Status of Trans-Arterial Embolization in Pain Management of Musculoskeletal Inflammatory Conditions - An Evidence-Based Review.

OBJECTIVE: To summarize the literature on trans-arterial embolization in inflammatory musculoskeletal conditions, focusing on efficacy and safety. MATERIALS AND METHODS: PRISMA guidelines were followed. A systematic literature search revealed 19 studies, with a total of 394 participants, eligible for inclusion. RESULTS: The included studies consisted of case reports/series and non-randomized interventional studies, with knee osteoarthritis and adhesive capsulitis of the shoulder as the most frequent conditions. In all studies except one, pain was reduced up to four years after treatment. All adverse events were transient. Due to high heterogeneity, meta-analysis was not possible. CONCLUSION: The included early studies showed encouraging results regarding efficacy and safety. However, randomized, placebo-controlled trials are warranted.

Bone remodeling and implant migration of uncemented femoral and cemented asymmetrical tibial components in total knee arthroplasty - DXA and RSA evaluation with 2-year follow up.

BACKGROUND: Aseptic loosening is one of the major reasons for late revision in total knee arthroplasty (TKA). The risk of aseptic loosening can be detected using radiostereometric analysis (RSA), whereby micromovements (migration) can be measured, and thus RSA is recommended in the phased introduction of orthopedic implants. Decrease in bone mineral density (BMD), as measured by dual-energy x ray absorptiometry (DXA), is related to the breaking strength of the bone, which is measured concurrently by RSA. The aim of the study was to evaluate bone remodeling and implant migration with cemented asymmetrical tibial and uncemented femoral components after TKA with a follow up period of 2 years. METHODS: This was a prospective longitudinal cohort study of 29 patients (number of female/male patients 17/12, mean age 65.2 years), received a hybrid Persona® TKA (Zimmer Biomet, Warsaw, IN, USA) consisting of a cemented tibial, an all-polyethylene patella, and uncemented trabecular metal femoral components. Follow up: preoperative, 1 week, and 3, 6, 12 and 24 months after surgery, and double examinations for RSA and DXA were performed at 12 months. RSA results were presented as maximal total point of motion (MTPM) and segmental motion (translation and rotation), and DXA results were presented as changes in BMD in different regions of interest (ROI). RESULTS: MTPM at 3, 6, 12, and 24 months was 0.65 mm, 0.84 mm, 0.92 mm, and 0.96 mm for the femoral component and 0.54 mm, 0.60 mm, 0.64 mm, and 0.68 mm, respectively, for the tibial component. The highest MTPM occurred within the first 3 months. Afterwards most of the curves flattened and stabilized. Between 12 and 24 months after surgery, 16% of femoral components had migrated by more than 0.10 mm and 15% of tibial components had migrated by more than 0.2 mm. Percentage change in BMD in each ROI for distal femur was as follows: ROI I 26.7%, ROI II 9.2% and ROI III 3.3%. BMD and at the proximal tibia: ROI I 8.2%, ROI II 8.6% and ROI III 7.0% after 2 years compared with 1 week postoperative results. There was no significant correlation between maximal percentwise change in BMD and MTPM after 2 years. CONCLUSION: Migration patterns and changes in BMD related to femoral components after TKA in our study correspond well with previous studies; we observed marginally greater migration with the tibial component.

Pretreatment Plasma IL-6 and YKL-40 and Overall Survival after Surgery for Metastatic Bone Disease of the Extremities.

BACKGROUND: Plasma IL-6 and YKL-40 are prognostic biomarkers for OS in patients with different types of solid tumors, but they have not been studied in patients before surgery of metastatic bone disease (MBD) of the extremities. The aim was to evaluate the prognostic value of plasma IL-6 and YKL-40 in patients undergoing surgery for MBD of the extremities. PATIENTS AND METHODS: A prospective study included all patients undergoing surgery for MBD in the extremities at a tertiary referral center during the period 2014-2018. Preoperative blood samples from index surgery were included. IL-6 and YKL-40 concentrations in plasma were determined by commercial ELISA. A total of 232 patients (median age 66 years, IQR 58-74; female 51%) were included. RESULTS: Cox regression analysis was performed to identify independent prognostic factors for OS. IL-6 correlated with YKL-40 (rho = 0.46, p < 0.01). In univariate analysis (log2 continuous variable) IL-6 (HR = 1.26, 95% CI 1.16-1.37), CRP (HR = 1.20, 95% CI 1.12-1.29) and YKL-40 (HR = 1.25, 95% CI 1.15-1.37) were associated with short OS. In multivariable analysis, adjusted for known risk factors for survival, only log2(IL-6) was independently associated with OS (HR = 1.24, 95% CI 1.08-1.43), whereas CRP and YKL-40 were not. CONCLUSION: High preoperative plasma IL-6 is an independent biomarker of short OS in patients undergoing surgery for MBD.