Cost-Effectiveness of Bone SPECT/CT in Painful Total Knee Arthroplasty

The purpose of this study was to quantify the economic value of bone SPECT/CT versus CT or metal artifact reduction sequence (MARS)-MRI for the diagnostic assessment of recurrent moderate-to-severe pain after total knee arthroplasty (TKA). Methods: An Excel-based simulation model was developed to compare bone SPECT/CT versus CT or MARS-MRI from a payer perspective. Clinical endpoints (diagnosis-delayed or otherwise, and the subsequent treatment and complications) and their corresponding cost data (2017 U.S. dollars) were obtained by performing a best evidence review of the published literature. Studies were pooled and parameters weighted by sample size. A cost-utility analysis was performed estimating the incremental cost per quality-adjusted life years gained between bone SPECT/CT and the comparative scans. One-way (±25%) sensitivity analysis was performed to gauge the model robustness. Results: For every 1,000 TKA patients, diagnostic bone SPECT/CT was expected to lead to 3-y cost savings up to $1,867,695 versus CT (or $622.6 per patient per year) and $1,723,435 versus MARS-MRI (or $574.5 per patient per year) for a payer. With corresponding incremental quality-adjusted life years gains of 39.7 and 41.0 against CT and MARS-MRI, SPECT/CT can be considered as a cost-saving and dominant strategy in the workup of persistent/recurrent pain in TKA patients. The model was limited by the still sparse literature data, was most sensitive to imaging-related sensitivity/specificity, but proved robust for varying prevalence of surgical/nonsurgical causes of pain. Conclusion: Bone SPECT/CT is a potentially highly cost-saving and dominant imaging intervention versus CT or MARS-MR scanning in patients with recurrent and persistent knee pain after TKA.