The Femoral Neck Unveiled: A Multimodality Imaging Roadmap

The femoral neck, a critical biomechanical conduit, is susceptible to diverse pathologies requiring precise radiological diagnosis to prevent adverse outcomes. This review serves as a visual and textual reference for enhancing diagnostic confidence through pattern recognition and multimodality correlation. Imaging evaluation begins with radiography, offering an excellent osseous overview but limited sensitivity for early disease. Computed tomography (CT) provides superior bony detail for trauma and surgical planning, while magnetic resonance imaging (MRI) is the most sensitive modality for marrow and soft tissue pathology. Ultrasound excels at evaluating periarticular soft tissues, while nuclear medicine provides functional assessment of multifocal disease. A systematic, integrated diagnostic algorithm is essential. An initial radiograph is pivotal for all presentations. For negative radiographs with high clinical suspicion, MRI is the suggested next step to detect occult fractures or osteonecrosis. CT is paramount for characterising complex fractures, and MRI is indicated for staging aggressive or indeterminate lesions. Pathologies span normal variants, developmental morphologies, benign and malignant neoplasms, and traumatic conditions. Key variants include bone islands, synovial herniation pits, and Ward's triangle, which must be distinguished from pathology. Developmental changes, such as cam morphology, predispose to early osteoarthritis. While benign lesions such as osteoid osteoma and fibrous dysplasia occur, metastases and myeloma are most common in adults. Trauma, notably femoral neck fractures, carries a high risk of avascular necrosis. The radiologist's crucial role is synthesising imaging patterns with clinical data to distinguish normal from abnormal, guide management, and improve patient outcomes.