Can bone SPECT/CT and 18 F-NaF PET/CT diagnose the cause of persistent pain due to motion sparing devices: a case series

Purpose: Can positron emission tomography/CT (18 F-NaF PET/CT) and Bone single-photon emission CT (SPECT/CT) be used to diagnose the cause of persistent pain in motion-sparing devices? Interspinous devices (ISD) and cervical disc arthroplasty (CDA) are used increasingly. While a desired outcome is achieved in a portion of these patients, others develop persistent postoperative symptoms. Etiology of these symptoms is diagnosed with imaging such as x-ray, computed tomography (CT), or magnetic resonance imaging (MRI). Despite these modalities, there is a subset of patients with persistent pain who remain without a diagnosis. In these patients, Bone SPECT/CT and 18F-NaF PET/CT can aid in the detection of complications including implant loosening, screw loosening, and infection. Methods: Retrospective review was performed at a tertiary care center to identify patients with persistent pain following placement of motion sparing devices and underwent Bone SPECT/CT or 18 F-NaF PET/CT. Results: Six patients who underwent 99mTc-MDP Bone SPECT/CT or 18 F-NaF PET/CT for persistent postoperative symptoms following ISD placement or CDA were included. Of the six patients, four patients demonstrated uptake on 99mTc-MDP Bone SPECT/CT or 18 F-NaF PET/CT. Based on imaging findings, one patient underwent removal of the artificial disc, two patients were offered but declined surgery for device removal, and one patient was offered a spinal cord stimulator trial with the option of device removal if pain persisted. Conclusion: 99mTc-MDP Bone SPECT/CT and 18 F-NaF PET/CT can guide surgical recommendations for patients with persistent symptoms following ISD placement or CDA.