Genicular Artery Caliber in Patients with Chronic Pain after Knee Arthroplasty: An Age-Matched Case-Control Study

Background: Chronic post–knee arthroplasty pain (CPKAP) affects approximately 20% of patients. While genicular artery embolization (GAE) treats neovascularity in painful knee osteoarthritis, its role in CPKAP remains unclear. This study compared genicular artery caliber in patients with CPKAP and pain-free arthroplasty controls. Materials and Methods: A retrospective review of lower extremity computed tomographic angiograms performed between January and August 2024 was conducted. Patients with CPKAP were matched to pain-free arthroplasty controls by sex and age. Using multiplanar reformats orthogonal to the vessel axis, diameters, circumferences, and cross-sectional areas of the descending, superior medial, and superior lateral genicular arteries (DGA, SMGA, SLGA) and superficial femoral artery (SFA) were measured. Two independent readers performed measurements, and intraclass correlation coefficients (ICCs) were calculated. Paired t-tests were used for comparison. Results: Twenty-two patients were included (11 CPKAP, 11 controls). Mean age was 64 versus 67 years, with 73% female in each group. Body mass index and time from arthroplasty to CTA did not differ (p > 0.05). CPKAP patients had larger DGA diameters (3.26 ± 0.35 vs. 2.59 ± 0.28 mm), circumferences (11.1 ± 1.47 vs. 8.65 ± 1.18 mm), and cross-sectional areas (9.14 ± 2.03 vs. 5.44 ± 1.55 mm²; all p < 0.01), including increased DGA:SFA ratios. No differences were observed for SMGA or SLGA. ICCs were excellent for DGA and SFA. Conclusions: CPKAP patients demonstrate enlarged DGA caliber compared with pain-free arthroplasty controls, suggesting pathologic neovascular changes and supporting further evaluation of GAE.