Diagnosis of Chronic Infection in Spinal Instrumentation Using PET CT

Introduction:

The diagnosis and management of Chronic implant related infection remains a challenge to the Spinal surgeon. Patients often present with minimal radiographic and biochemical indication of infection. We present our 5 year experience of the use of FDG PET CT in the diagnosis and management of suspected infection of spinal instrumentation.

Method:

Retrospective review of all patients at a single centre referred over 5 years for PET CT for possible implant related infection. All FDG Scan reports of symptomatic patients with implants in situ at the time of scanning were assessed, Case notes and microbiology where applicable were reviewed.

Result:

57 patients were referred for scan at greater than 1 year following intervention. 53 patients had full record available for assessment. Median age at scan 25 (18- 75). Time from Index surgery ranged from 18-216 months. 24 scans (45%) were reported as consistent with low grade infection of which 10 were managed operatively with revision or removal of implant. Microbiology was positive in 70% of cases with Proprionerbacter Acnes the predominant positive finding (4/7).

Conclusion:

A positive scan correlated strongly with the presence of microbiological infection and is a useful guide in the management of pain in patients with spinal implants.