Bloodpool SPECT as part of bone SPECT/CT in painful total knee arthroplasty (TKA): validation and potential biomarker of prosthesis biomechanics

PurposeTo compare bloodpool SPECT with planar imaging in bone SPECT/CT of painful total knee arthroplasty (TKA) with respect to inter-rater agreement, confidence, prosthesis outcome, and biomechanical functioning.MethodsRetrospective study of bloodpool SPECT and planar control images. Four raters used the validated Bruderholz scheme and a 5-point scale to grade uptake. Inter-rater agreement and overall confidence scores were calculated. Variable cluster analysis was performed to identify patterns of uptake, and associations between patterns and prosthesis outcome and biomechanical functioning were examined.ResultsIn all, 55 knees in 43 patients were analyzed (median follow-up 17months; revision rate 21.8%). SPECT significantly improved inter-rater agreement in 24% of regions (all P