Differential Diagnosis of Painful Bony Protrusion After Hip Nail Fixation

Diagnostic Approach

• The American College of Radiology recommends obtaining AP pelvis and lateral hip radiographs first to evaluate hardware position, heterotopic ossification, periprosthetic fractures, and greater trochanter pathology 1, 2
• Radiographs should be the first imaging modality to assess hardware position and identify protrusion, according to the Journal of the American College of Radiology 1, 2
• The American College of Radiology suggests comparing radiographs with prior postoperative radiographs to assess for hardware migration or progressive changes 1

Imaging Findings

• Trochanteric surface irregularities >2mm may indicate abductor tendon abnormalities, as reported by the Journal of the American College of Radiology 1
• Periosteal bone reaction visible on CT is a specific finding for complications, according to the European Journal of Nuclear Medicine and Molecular Imaging 3

Advanced Imaging

• If radiographs are negative or equivocal but clinical suspicion remains high, the American College of Radiology recommends obtaining MRI for fracture detection, soft tissue evaluation, and hematoma identification 2
• MRI with metal artifact reduction sequences (MARS-MRI) enables evaluation of soft tissues around the prosthetic hip, particularly the pseudocapsule and tendons, as suggested by Praxis Medical Insights 4
• CT with metal artifact reduction (MAR) provides detailed assessment of bony structures and hardware position, according to Praxis Medical Insights 4
• Ultrasound can assess soft tissues adjacent to hardware without metal artifacts, as reported by Praxis Medical Insights 4