Objective: We evaluated the information content of knee bone scintigraphy, including pattern, localization and intensity of retention relative to radiographic features of knee osteoarthritis (rOA), knee alignment, and knee symptoms.
Methods: A total of 308 knees (159 subjects) with symptomatic and radiographic knee OA (rOA) of at least one knee were assessed by late phase technetium-99m-methylene disphosphonate bone scintigraph, fixed-flexion knee radiograph, full limb radiograph for knee alignment, and for self-reported knee symptom severity. Generalized linear models were used to control for within subject correlation of knee data.
Results: The compartmental localization (medial versus lateral) and intensity of knee bone scan retention were associated with the pattern (varus versus valgus) (p<0.001) and severity (p=0.0008) of knee malalignment, and localization and severity of rOA (p<0.0001). Bone scan agent retention in the tibiofemoral, but not patellofemoral compartment, was associated with severity of knee symptoms (p=0.0009), and persisted after adjusting for rOA (p=0.0012).
Conclusion: To our knowledge, this is the first study describing a relationship between knee malalignment, joint symptom severity, and compartment specific abnormalities by bone scintigraphy. This work demonstrates that bone scintigraphy as a sensitive and quantitative indicator of symptomatic knee OA. Used selectively, bone scintigraphy is a dynamic imaging modality that holds great promise as a clinical trial screening tool and outcome measure.