Search

To the best of the authors’ knowledge, this is the first published case of monophasic synovial sarcoma (SS) initially diagnosed as Ewing’s sarcoma (ES), yet successfully treated with chemotherapy in a 24-year-old patient. The initial diagnosis showed a monotonous round cell tumor and positivity for CD99, characteristic of ES; however, the cytology was negative for the classic EWSR1 rearrangement of ES. The patient was treated with the standard chemotherapy protocol of ES – COG AEWS1031 Regimen A with vincristine, doxorubicin, cyclophosphamide, and mesna – as well as with wide resection. Post-resection tissue submission showed additional morphologic features which led to a re-evaluation of the classification of the tumor as well as additional molecular studies; these revealed positivity for translocations of SS18 (18q11.1) in 100% of the nuclei, which is most characteristic of SS, thus, reclassifying the neoplasm as a SS tumor. This case underscores the importance of considering several pathologic entities in the differential diagnosis of small, round blue cell tumors, including ES, SS, and lymphoma. It also demonstrates the importance of using chromosomal identification for a more definitive diagnosis, rather than relying on histological features and markers which are found in more than one tumor classification. There is conflicting evidence of the impact of chemotherapy on survival in SS, as it is primarily treated with radiation therapy. Since SS is rare, prospective studies on the effect of chemotherapy on survival are limited in number. However, our case study demonstrates that chemotherapy is another modality that can be used in the treatment of SS neoplasms.

Aadit Shah, Eric Lepkowsky, Alexander Duke, Meghan Moriarty, Haley Riordan, Fazel Khan Stony Brook University Hospital, Department of Orthopaedics, Stony Brook, NY, 11794, USACorrespondence: Aadit ShahStony Brook University Hospital, Department of Orthopaedics, 101 Nicolls Road, HSC T-18 – 089, Stony Brook, NY, 11794, USATel +1-631-786-9484Email Aadit.Shah@stonybrookmedicine.eduAbstract: Osteoarthritis (OA) is a common pathology affecting the knee joint. Twenty percent of the cartilaginous tumors of bone are in the distal femur. This presents a challenge for treating patients with knee OA who also have ipsilateral distal femur cartilage tumors. We propose a classification system for knee OA with ipsilateral cartilaginous tumor and a treatment approach to address this issue. Intramedullary guides are avoided when performing total knee arthroplasty (TKA) in these patients so as not to further contaminate the femur with tumor cells. A non-image-based stereotactic surgical system is favored at our institution to achieve this goal. Seven patients underwent classification and treatment with TKA utilizing this approach. Average final follow-up was 15.3 months. Component alignment averaged 89.2° and all patients had 0° of extension with an average flexion to 107.5°. There were no postoperative complications and no radiographic evidence of component complication, tumor recurrence, or tumor expansion. Few studies have reported on the treatment of knee OA with concurrent cartilaginous tumor of the distal femur. All patients treated with the proposed approach had their OA successfully treated without complication related to their cartilaginous tumor or TKA components. This case series presents a novel classification and treatment algorithm to potentially guide arthroplasty surgeons in approaching these often-concurrent occurring pathologies.Keywords: total knee arthroplasty, osteoarthritis, cartilage tumor, enchondroma, chondrosarcoma

Alexander Duke, Richard Marchese, David E Komatsu, James Barsi Department of Orthopaedics and Rehabilitation, Stony Brook University Hospital, Stony Brook, NY, USACorrespondence: Alexander Duke, Stony Brook University Hospital, Health Sciences Center T18-089, Stony Brook, NY, 11794, USA, Tel +1 631 972-8324, Fax +1 631 444-3502, Email alexander.duke@stonybrookmedicine.eduBackground: Adolescent Idiopathic Scoliosis (AIS) is the most common type of scoliosis affecting adolescents, with approximately 2– 4% of children being diagnosed. Crucial to the diagnosis and management are radiographic imaging, which allow physicians to assess and treat – from initial visits through surgical planning and post-operative management. While initial stages require low levels of exposure to radiation, via x-rays, as patients progress in disease severity exposure becomes larger with pre-operative, intra-operative and post-operative CT scans. While many studies have evaluated exposure during AIS treatment, few have assessed the cumulative radiation exposure adolescents receive during their evaluation. The purpose of our study is to complete a comprehensive review on cumulative radiation exposure and determine what stages in AIS treatment expose patients to the highest level of radiation over a duration of 2 years.Methods: A retrospective chart review of 109 AIS cases (29M, 80F), mean age 14.9 ± 2.3 years was completed to assess and quantify each imaging modality used. Employing a radiation detector, each imaging modality was then assessed, and estimated radiation exposures were determined. Statistical analysis was completed utilizing averaged patient exposures during each selected period in AIS management.Results: Mean estimated radiation doses (StDev) were 60.94 mrem (± 0.609 mrem) for two x-rays (full-length AP and lateral radiograph of the entire spine), 12.92 mrem (± 1.292 mrem) for each fluoroscopy exposure, and 1340.60 mrem (± 13.406 mrem) per CT scan. Based on these values, estimated subject exposures were calculated. The total estimated radiation exposure over a 2-year period was 5572.74 mrem (± 1428.88 merm) or 2786.37 mrem (± 714.43 mrem) per year.Conclusion: The two-year cumulative radiation exposure is below the recommended exposure by Nuclear Regulatory Commission and OSHA. As expected, CT exposure presents the largest radiation exposure to patients with AIS throughout their operative management.Level of Evidence: III, retrospective study.Keywords: scoliosis, radiation, adolescent idiopathic scoliosis

Electrical machines with high-temperature superconducting (HTS) armature windings can benefit from high power density and efficiency. Furthermore, by using permanent magnets (PM) on the rotor, the cryogenic system can be significantly simplified compared with the fully superconducting (SC) machines or the machines with SC field windings. Compared with the conventional electrical machines, the performance of machines with HTS armature windings can be more sensitive to the design parameters due to the interaction between the operating current and the flux density. In this article, the influence of stator geometry on the machine with HTS armature windings and PM rotor is investigated. By considering the interaction between the operating current and the flux density, an iteration procedure for calculating the operating current of the HTS armature windings is proposed. A 10-MW surface-mounted PM wind power generator with HTS armature windings is studied by the finite element analysis. It is found that machines with different coil angle have different behaviors when changing the tooth width and the dimensions of tooth tips, which is different from conventional electrical machines. A new design and optimization method is then developed. Finally, the optimal design is identified with global optimization.

In this article, the operating current and torque of surface-mounted permanent magnet (SPM) wind power generators with high-temperature superconducting (HTS) armature windings are analyzed. The influence of coil location and current angle on the electromagnetic performance is investigated systematically. The results show that the location of the HTS coils significantly affects the operating current and torque. Furthermore, the maximum torque current angle of SPM wind power generators with HTS armature windings can be different from 180° due to the interaction between the armature and magnet fields. A design optimization method for wind power generators with HTS armature windings is developed in this article. The optimal design is then identified with consideration of the coupling influence of coil location and current angle.

In this paper, the optimal designs of a surface-mounted permanent magnet (SPM) machine and various topologies of the transverse flux permanent magnet (TFPM) machine are comprehensively investigated and compared at 3 kW and 3 MW power levels. The 3 MW SPM machine surpasses all TFPM machine topologies in terms of power factor, efficiency, torque/mass and torque/cost ratios except for torque production capability. The highest torque achieved by the surface-mounted TFPM (SMTFPM) machine is 5.9% greater than that of the SPM machine. On the other side, 3 kW TFPM machines perform comparably better than the 3 MW TFPM machines due to less flux leakage and magnetic saturation with lower electrical loading. However, the highest torque from the 3 kW SMTFPM machine with iron bridges among all TFPM machine configurations still has 2.1% lower torque than the SPM machine, although it has higher torque/mass and torque/cost ratios than the 3 kW SPM machine.

Purpose: Although surgical repair of distal biceps tendon rupture improves functional outcomes compared with nonsurgical treatments, the choice of operative technique remains a matter of preference. This study retrospectively examined outcomes from a repair technique using a volar distal biceps reinsertion secured with a unicortical intramedullary button in the proximal radial tuberosity to determine its safety and functional outcomes. Methods: A single fellowship-trained shoulder and elbow surgeon treated 27 men, average age 48 years (range, 25–66 years), between 2012 and 2016. Patient-reported outcomes included the Disabilities of the Arm, Shoulder, and Hand and American Shoulder and Elbow Surgeons (ASES) satisfaction scores and the Mayo Elbow Performance Score. Average patient follow-up was 24 months. Results: This series had an overall complication rate of 39.3% (11 of 28): 9 lateral antebrachial cutaneous neuropraxias, one radial sensory nerve irritation, and one superficial infection. No complications of peripheral nerve injury, proximal radioulnar synostosis, or rerupture were observed. Results (mean ± SD) demonstrated low disability (Disabilities of the Arm, Shoulder, and Hand score = 2.9 ± 5.3), high satisfaction (American Shoulder and Elbow Surgeons score = 9.3 ± 1.4), and acceptable performance (Mayo Elbow Performance Score = 97.7 ± 6.3). Subcategory analysis identified a correlation between time to surgery and complications. Disability scores were higher in patients with workers’ compensation claims versus private insurance (mean, 11.0 vs 1.1). Conclusions: Further trials are required to compare the results and complication rates of this unicortical intramedullary button procedure with other established methods. Type of study/level of evidence: Therapeutic IV. Key words: distal biceps repair, single incision, unicortical button, volar incision

Transverse flux permanent magnet (TFPM) machines are a potential candidate for direct-drive wind power application due to high torque and power densities. The operating principle of TFPM machines is firstly described with various topologies available in literature, with the placement of magnets as a criterion for the classification of TFPM machine topologies. This review includes characteristics, power factor improvement, cogging torque minimization, material consideration, modelling techniques, and scalability. Different wind turbine concepts with direct-drive machines, control techniques and power converter topologies are also considered in this paper.

This paper investigates the influence of air gap on the electromagnetic performance of transverse flux permanent magnet (TFPM) machines with reference to surface permanent magnet (SPM) machines at two different power levels, i.e. 3 kW and 3 MW. The performance of a TFPM machine depends significantly on pole number, and therefore, the optimum pole number is selected and compared with an optimized SPM machine for different air gap lengths. It has been emphasized how the air gap length plays an influential role on various aspects of TFPM machines. However, the SPM machine shows much less dependency on the air gap length. For the 3 MW TFPM machine, air gaps below 2.5 mm should be beneficial in terms of mass and cost whereas the threshold for the air gap should be less than 1 mm for the 3 kW TFPM machine.

Background A large number of studies have examined the potential complications of calf deep vein thrombosis (DVT). There is no consensus on when or how to treat patients to prevent these complications. This systematic review assessed the rate of proximal propagation, pulmonary embolism, major bleeding and recurrence in patients with isolated calf DVT. Methods Database searches of MEDLINE, the Cochrane Library, Scopus, CINAHL and Web of Science were undertaken along with extensive cross-referencing. Two independent reviewers screened the papers using stringent inclusion and exclusion criteria. Included studies were graded on six methodological standards. Data on propagation, pulmonary embolism, recurrence and major bleeding were abstracted. Results A total of 4261 papers were found; 15 met the inclusion criteria, including five randomized clinical trials and ten prospective cohort studies. The propagation rate to the popliteal vein or above was around 9 per cent and the rate of pulmonary embolism was close to 1·5 per cent. No studies found anticoagulant therapy to reduce the rate of adverse outcomes. Conclusion The literature on calf DVT is heterogeneous, limiting conclusions from data analysis. Adverse outcomes are infrequent and studies do not suggest that they are reduced by anticoagulation.

n/a

n/a

n/a

n/a

n/a

n/a

n/a

n/a

n/a

n/a

n/a

n/a

n/a

n/a

n/a

n/a

n/a

n/a

n/a

n/a