This case explores the role of SPECT/CT in evaluating persistent pain following hip arthroplasty. It demonstrates how combined functional and anatomical imaging can help distinguish septic from aseptic prosthetic loosening by correlating tracer uptake patterns with structural CT changes. Key imaging features such as irregular lucencies, osteosclerosis, and periosteal reaction are discussed, highlighting their diagnostic significance in musculoskeletal nuclear medicine.

Learning Objectives

By the end of this case, participants will be able to:

• Identify the characteristic SPECT/CT uptake patterns associated with septic prosthetic loosening.
• Differentiate septic from aseptic loosening based on CT lucency morphology, distribution, and tracer uptake congruence.
• Recognize associated secondary findings such as osteosclerosis, periosteal reaction, and cortical thickening.
• Appreciate the value of correlating early-phase and delayed-phase tracer uptake with CT changes at the bone–prosthesis interface.
• Understand normal post-operative uptake patterns in uncemented hip prostheses and how they differ from pathological findings.