Orthopaedic Radiological Investigations

Overview

  • Radiographs first, two orthogonal views, joint above and below for long bone injuries
  • CT for intra-articular fractures, spinal trauma and planning
  • MRI for soft tissue, cartilage, marrow, occult fracture, infection and tumour
  • Ultrasound for tendons, masses, effusions and guided procedures
  • Bone scintigraphy and SPECT-CT localise occult pathology and loosening
  • Weigh radiation dose, contrast safety and implant compatibility

Western Health Orthopaedic Registrar presentation – Orthopaedic Radiological Investigations By Dr Amy Gibbens

Investigations

  • Radiographs need two orthogonal views, with joints above and below for long bones
  • Rosenberg view for knee joint space, standing long leg films for alignment
  • Judet views for the acetabulum, Zanca for the acromioclavicular joint, Merchant for the patella
  • Lytic lesions appear only after 30 to 50 percent bone loss
  • CT for intra-articular planning, pelvis, spinal trauma, union and rotation
  • CT angiography after knee dislocation with an abnormal ankle brachial index
  • MRI T1 shows bright fat, best for marrow replacement and occult fracture
  • T2 shows bright fluid, and STIR is sensitive for stress injury, infection and bone bruising
  • Gadolinium arthrography for labral and cartilage lesions
  • MARS sequences for pseudotumour around metal-on-metal implants
  • MRI contraindications include some pacemakers, cochlear implants and orbital metal
  • Ultrasound is dynamic and radiation free, used for DDH before head ossification
  • Technetium MDP bone scan reflects osteoblastic activity, so myeloma may be cold
  • Labelled white cell scans improve specificity for infection
  • SPECT-CT for painful arthroplasty and spine, PET-CT for sarcoma and lymphoma staging

Complications

  • Pelvis and spine CT give among the largest routine orthopaedic doses
  • ALARA applies in radiosensitive children, favouring ultrasound or MRI
  • Staff wear lead and thyroid shields and stand on the receptor side

Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.