ICAR: endoscopic skull‐base surgery

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A new era for understanding amyloid structures and disease

The aggregation of proteins into amyloid fibrils and their deposition into plaques and intracellular inclusions is the hallmark of amyloid disease. The accumulation and deposition of amyloid fibrils, collectively known as amyloidosis, is associated with many pathological conditions that can be associated with ageing, such as Alzheimer disease, Parkinson disease, type II diabetes and dialysis-related amyloidosis. However, elucidation of the atomic structure of amyloid fibrils formed from their intact protein precursors and how fibril formation relates to disease has remained elusive. Recent advances in structural biology techniques, including cryo-electron microscopy and solid-state NMR spectroscopy, have finally broken this impasse. The first near-atomic-resolution structures of amyloid fibrils formed in vitro, seeded from plaque material and analysed directly ex vivo are now available. The results reveal cross-β structures that are far more intricate than anticipated. Here, we describe these structures, highlighting their similarities and differences, and the basis for their toxicity. We discuss how amyloid structure may affect the ability of fibrils to spread to different sites in the cell and between organisms in a prion-like manner, along with their roles in disease. These molecular insights will aid in understanding the development and spread of amyloid diseases and are inspiring new strategies for therapeutic intervention

Long‑Term Outcome of Endoprosthetic Replacement for Proximal Femur Giant Cell Tumor

Introduction: Giant cell tumor (GCT) of bone is locally aggressive benign tumor involving the epiphysis of long bones in young adults. Various treatment options include intralesional curettage, extended curettage, wide resection, resection and reconstruction and amputation. The main variables to be considered for planning treatment include the site of involvement and Campanacci stage of the tumor. Functional and oncological outcomes of these treatment options vary widely, the predominant detrimental factor being tumor recurrence rate. Aim: A study was conducted to evaluate the long‑term oncological and functional outcome of patients with GCT of the proximal femur that underwent tumor resection and endoprosthetic replacement. Materials and Methods: Eleven patients with Campanacci stage‑III GCT of proximal femur who underwent wide excision of tumor and endoprosthesis replacement with a mean follow‑up the duration of 10.6 years were assessed using standard proforma. The treatment outcome was evaluated using the Revised Musculoskeletal Tumor Society Rating Scale for the lower extremity. Results: At mean follow‑up the duration of 10.6 years, none of the cases had tumor recurrence, infection, prosthesis loosening or dislocation. All the patients were community ambulators among whom eight patients were walking without support while three patients were using a cane for support. The mean total Musculoskeletal Tumor Society Score was 26.8 out of 30 indicating the good outcome. Conclusions: The authors recommend that wide resection and endoprosthetic replacement should be considered as a preferred treatment option for proximal femur GCT as the functional, and oncological outcome is satisfactory with this modality of treatment.Keywords: Endoprosthesis megaprosthesis, giant cell tumor of bone, proximal femu

Multifocal Skeletal Tuberculosis Involving the Lumbar Spine and Iliac Bone, Mimicking a Malignant Bone Tumour: A Case Report

Multifocal osteoarticular tuberculosis is uncommon and accounts for approximately10% of all cases of osteoarticular tuberculosis. Concomitant vertebral and iliac bone tuberculosis has not been reported in the literature to date. We report one such case for its unusual clinical and radiological presentation, which had presentation more similar to a malignant bone tumour than an infection