Periacetabular bone metabolism following hip revision surgery. PET-based evaluation of allograft osteointegration

Novel Musculoskeletal and Orthopedic Applications of 18F-Sodium Fluoride PET

PET imaging with ¹⁸F-sodium fluoride (NaF), combined with computed tomography or magnetic resonance, is a sensitive method of assessing bone turnover. Although NaF-PET is gaining popularity in detecting prostate cancer metastases to bone marrow, osseous changes represent secondary effects of cancer cell growth. PET tracers more appropriate for assessing prostate cancer metastases directly portray malignant activity and include ¹⁸F-fluciclovine and prostatic specific membrane antigen ligands. Recent studies investigating NaF-PET suggest utility in the assessment of benign musculoskeletal disorders. Emerging applications in assessing traumatic injuries, joint disease, back pain, orthopedic complications, and metabolic bone disease are discussed.

Diagnosis of peri-prosthetic loosening of total hip and knee arthroplasty using 18F-Fluoride PET/CT

Periprosthetic loosening, either aseptic or induced by periprosthetic joint infection remains a major long term complication and challenge in orthopedics and trauma surgery. Sensitivity of potential loosening of the material and other causes of a painful prosthesis is essential for choosing the respective treatment option and providing the needed resources. ¹⁸F-Fluoride is a radiopharmaceutical which shows a high affinity to bone and a rapid blood clearance.

The objective of this study was to assess ¹⁸F-Fluoride PET/CT´s sensitivity and specificity in diagnosing periprosthetic loosening in total hip and knee arthroplasty.

We included 26 patients with 24 hip and 13 knee prostheses in our retrospective study with radiological or clinical suspicion of peri-prosthetic loosening at least one year after implantation. Results of ¹⁸F-Fluoride PET/CT imaging were compared with surgical results or clinical follow-up if surgery was not performed. On the basis of our data we found a sensitivity of 95.00 %, a specificity of 87.04 % and an accuracy of 89.19 % for ¹⁸F-Fluoride PET/CT.

The results of our study show that ¹⁸F-Fluoride PET/CT is a useful and promising technique in diagnosing periprosthetic loosening of total hip and knee arthroplasties. Further investigation should focus on different uptake patterns of the isotope in periprosthetic joint infection and therefore distinguishing aseptic from septic loosening and enhancing the diagnostic value of this imaging method.

Sodium 18F-fluoride PET/CT of bone, joint, and other disorders

The use of (18)F-sodium fluoride ((18)F-NaF) with PET/CT is increasing. This resurgence of an old tracer has been fueled by several factors including superior diagnostic performance over standard (99m)Tc-based bone scintigraphy, growth in the availability of PET/CT imaging systems, increase in the number of regional commercial distribution centers for PET radiotracers, the recent concerns about potential recurring shortages with (99m)Tc-based radiotracers, and the recent decision by the Centers for Medicare and Medicaid Services to reimburse for (18)F-NaF PET/CT for evaluation of patients with known or suspected bone metastases through the National Oncologic PET Registry. The major goal of this article is to review the current evidence on the diagnostic utility of (18)F-NaF in the imaging assessment of the bone and joint in a variety of clinical conditions.