LASER-ASSISTED FLUORESCENT ANGIOGRAPHY IN PRIMARY AND REVISION KNEE ARTHROPLASTY

Introduction & Aim Prosthetic joint infection (PJI) is the leading complication following total knee arthroplasty (TKA). Surgical debridement is a critical procedure to address PJI during revision surgery, yet adequate debridement is currently undefined and relies upon subjective assessment. Laser-assisted fluorescent angiography (LAFA) is an intraoperative technology that has been utilized successfully to assess tissue perfusion in ophthalmology and plastic surgery. However, the potential of this technology to guide debridement during knee revisions is wholly unexplored. As an initial step in addressing this research gap, the purpose of this study was to demonstrate the feasibility of detecting a fluorescently labeled dye within deep tissues utilizing LAFA during revision TKAs. Methods Following IRB approval, fourteen patients (8 males and 6 females) were included in the study undergoing either primary TKA (N = 6) or revision TKA (N = 8, 5 aseptic and 3 septic cases). Intraoperatively, before and after debridement, indocyanine green dye (2.5 mg/ml) was injected intravenously and a charge-coupled device camera (using a standard focal depth) recorded tissue perfusion fluorescence for two minutes. Statistical analysis consisted of ANOVA with post-hoc Tukey's test. Results Egress rate and total egress fluorescence values were elevated by 2- to 30-fold (P < 0.05) for patients during revision versus patients undergoing primary TKA. When aseptic and septic revisions were analyzed as separate groups, an interaction between debridement and procedure was observed for ingress rate within soft tissue, P = 0.0214. Conclusions LAFA was successful at evaluating the delivery of fluorescently labeled dye within deep tissues of revision TKAs. Future studies will explore the use of LAFA assessment of localized perfusion for the identification of debridement margins and the improvement of PJI patient outcomes. Acknowledgements NIH NIAMS Award K08AR073921