Osteomyelitis, Septic Arthritis, and Bone and Joint Infections — WACS Viva & Clinical Scenarios (Musculoskeletal and Trauma Imaging)

Exam-style osteomyelitis, septic arthritis, and bone and joint infections viva scenarios with examiner probes and model answers for Radiology candidates.

Scenarios covered

• SCENARIO 1: A 7-year-old child known to have homozygous sickle cell anaemia (HbSS) presents to the emergency department with a 3-day history of acute severe left thigh pain, swelling, and low-grade fever. Describe your step-by-step diagnostic imaging approach to differentiate acute vaso-occlusive bone infarction from acute bacterial osteomyelitis, detail the key findings across plain radiography, ultrasound, and MRI, and state the most common causative pathogens in this clinical context.
• SCENARIO 2: A 24-year-old male presents with recurrent purulent drainage from an anterior tibial sinus tract following an open fracture sustained two years prior. Describe the classical plain film and computed tomography (CT) hallmarks of chronic osteomyelitis, explain the underlying pathophysiological mechanisms of these findings, and discuss the long-term malignant and systemic complications associated with neglected disease.
• SCENARIO 3: An 18-month-old infant is brought in with acute irritability, refusal to bear weight on the right lower limb, and a flexed, abducted, externally rotated right hip. Detail the emergency imaging pathway for suspected paediatric septic arthritis, specifying diagnostic ultrasound criteria for hip joint effusion, plain radiographic signs, and the technical principles of image-guided diagnostic joint aspiration.
• SCENARIO 4: A 38-year-old female presents with progressive thoracolumbar back pain, lower extremity spasticity, and a localized kyphotic deformity. Contrast the magnetic resonance imaging and computed tomography features of tuberculous spondylodiscitis (Pott disease) with those of acute pyogenic spondylodiscitis, emphasizing patterns of vertebral destruction, disc involvement, soft-tissue extension, and spinal canal compromise.
• SCENARIO 5: A 16-year-old boy presents with chronic, dull aching proximal tibial pain that worsens at night and is relieved partially by analgesics. Plain radiographs reveal a well-circumscribed metaphyseal lucency with a sclerotic rim. Discuss the radiological differential diagnosis with specific reference to Brodie abscess, explain characteristic MRI features including the penumbra sign, and outline the imaging signs of endemic chronic granulomatous and fungal infections such as mycetoma.