Quantitative in vivo assessment of bone allograft viability using 18 F-fluoride PET/CT after glenoid augmentation in reverse shoulder arthroplasty: a pilot study.

BACKGROUND: Success after glenoid bone augmentation in total shoulder arthroplasty depends on osseous integration and non-resorption. Standard imaging techniques, such as computed tomography (CT) and X-rays, cannot quantify bone viability. Therefore, we introduce a new technique to assess graft viability using 18 F-sodium fluoride (18 F-NaF) PET-CT for femoral allografts in reverse total shoulder arthroplasty (RSA).

MATERIALS AND METHODS: Patient charts were reviewed following glenoid augmentation using femoral allografts in reverse total shoulder arthroplasty. A total of seven patients were included in this study. 18 F-NaF PET-CT was used to assess graft viability and graft fusion. Semiquantitative assessment of 18 F-NaF uptake was performed by means of a standardized uptake value (SUV). Radiographs were used to assess fusion. The mean age of the patients at the time of follow-up was 83.4 years (range 79-92), and the mean follow-up was 44.4 months.

RESULTS: Viability and fusion were confirmed in all allografts using semiquantitative analysis of 18 F-NaF PET-CT by means of standardized uptake value (SUVmax). Metabolic activity of medullary region of a vertebral spine was defined as a reference background. The mean value of maximum tracer activity in the allograft was not statistically different from native bone in the reference vertebrae (p = 0.14).

CONCLUSIONS: 18 F-NaF PET-CT is a practicable tool to quantitatively assess viability in large bone allografts after glenoid augmentation in RSA. The study shows viability and fusion in all allografts.

LEVEL OF EVIDENCE: Level IV, treatment study.