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

Genicular Artery Caliber in Patients with Chronic Pain after Knee Arthroplasty: An Age-Matched Case-Control Study | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Genicular Artery Caliber in Patients with Chronic Pain after Knee Arthroplasty: An Age-Matched Case-Control Study Bardia Nadim, Rebekah Bihun, Zhou Lan, Antonia Chen, Yan Epelboym This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8759916/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 4 You are reading this latest preprint version Abstract 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. Genicular artery embolization GAE knee osteoarthritis knee pain chronic post-knee arthroplasty pain Figures Figure 1 Figure 2 Figure 3 Background Knee arthroplasties are among the most frequently performed orthopedic surgeries worldwide. They are primarily performed for patients with refractory pain from knee osteoarthritis (OA). Epidemiological studies project a steady growth in the volume of these surgeries, with the number of primary total knee arthroplasty in the Medicare population alone predicted to reach upwards of 1.2 million by 2040 and 2.9 million by 2060 ( 1 , 2 ). While knee arthroplasties generally have favorable outcomes, chronic pain following knee arthroplasty (persistent beyond 3–6 months after surgery) remains relatively common, affecting approximately 20% of patients ( 3 , 4 ). Chronic post-knee arthroplasty pain (CPKAP) adversely affects function, quality of life, and patient satisfaction, and often lacks a single surgically correctable cause once infection, loosening, malalignment, and instability are excluded ( 4 ). Given the high prevalence of knee arthroplasty and the substantial subset of patients who experience CPKAP, understanding the etiologies of this pain is critical. A growing body of work suggests that synovial inflammation, pathologic neovascularization, and nociceptive innervation contribute to the complex pathogenesis of pain in knee OA ( 5 – 11 ). The basic premise is that inflammation induces angiogenesis, which facilitates structural remodeling and proliferation of unmyelinated sensory nerve fibers, thereby contributing to the persistence and amplification of pain ( 5 ). Genicular artery embolization (GAE) has emerged as a minimally invasive endovascular technique to target this process in knee OA with the intent to devascularize hyperemic synovium and modulate inflammatory pain signaling. Multiple systematic reviews and meta-analyses have reported clinically meaningful long-term pain relief and functional gains in patients with knee OA following GAE ( 12 – 14 ). However, the potential vascular changes associated with CPKAP remain less well characterized compared to the growing body of literature in the knee OA population. Early interventional experience indicates that GAE can be performed safely in post-arthroplasty patients with persistent pain. Early evidence suggests potential benefit of GAE in post-arthroplasty patients, with a small retrospective study by Epelboym et al. demonstrating short-term pain improvement at 1 and 3 months and a pilot study by Chau et al. showing sustained pain reduction at 12 months, though both studies were limited by small sample sizes and the overall literature remains sparse ( 15 , 16 ). Collectively, these preliminary findings of symptomatic improvement following GAE in CPKAP suggest that CPKAP may share, at least in part, a common vascular target with painful knee OA. Prior research has demonstrated positive correlations between knee OA severity and the caliber of the descending genicular artery (DGA) on computed tomographic angiography (CTA). While this is also a preliminary finding, it is important to explore whether patients with CPKAP demonstrate changes in genicular artery caliber as compared to controls who have undergone knee arthroplasty. Accordingly, the aim of this study was to retrospectively evaluate genicular artery caliber on CTA in patients with CPKAP compared with pain-free arthroplasty controls. Materials & Methods Institutional review board approval was obtained with a waiver of informed consent, in compliance with HIPAA regulations. We conducted a retrospective review of 22 knee arthroplasty patients with lower extremity CTA examinations performed at our institution from January 2024 to August 2024. Patients were eligible if they had undergone prior knee arthroplasty and had corresponding clinical documentation in the electronic medical record regarding the presence or absence of chronic postoperative knee pain (defined as ≥ 3 months after surgery) in the operated knee. Patients who underwent CTA for traumatic indications or demonstrated extensive atherosclerotic calcifications on imaging were excluded. Among the included patients, one patient in the CPKAP group and one patient in the control group had undergone unicompartmental (partial) knee arthroplasty rather than total knee arthroplasty; these patients were not matched within the same case–control pair. Patients were stratified into two groups: those with CPKAP and those with no chronic pain (NCP). For comparison, a case-control methodology was used in which patients with CPKAP were matched to NCP patients by age and sex. Demographic variables, including age, sex, body mass index (BMI), and number of days between arthroplasty and CTA, as well as imaging features, including measurements of the superficial femoral artery (SFA), descending genicular artery (DGA), superior medial genicular artery (SMGA), and superior lateral genicular artery (SLGA), were collected and analyzed. Arterial dimensions were obtained using multiplanar reformats orthogonal to the vessel axis and included vessel diameter, circumference, and cross-sectional area (Fig. 1 ). The SFA was measured at the level of the DGA origin, enabling calculation of a DGA-to-SFA ratio to evaluate the relative caliber of the DGA compared to its parent vessel. Two independent readers (BN and YE) performed all measurements. Statistical analyses were conducted using SAS software (SAS Institute, Cary, NC). Paired t -tests were used to compare cases and matched controls with statistical significance set at p < 0.05. Interobserver agreement between the two readers was assessed using intraclass correlation coefficients (ICC). Analyses of the averaged measurements from both readers were used for group comparisons. Results A total of 22 patients were included, comprising 11 with CPKAP and 11 age- and sex-matched knee arthroplasty controls without pain. Of the 22 patients included, two had undergone unicompartmental knee arthroplasty (one in the CPKAP group and one in the control group). The mean age was 64.0 ± 6.1 years in the CPKAP group (range = 53–73) and 67.2 ± 6.0 years in the NCP group (range = 64–78). Females accounted for 73% (8/11) of each cohort. The mean BMI was 32.2 ± 5.8 kg/m 2 in the CPKAP group and 30.1 ± 6.5 kg/m 2 in the NCP group (p = 0.49). The average interval between arthroplasty and CTA was 2070 ± 2730 days for the CPKAP group and 2732 ± 1646 days for the NCP group (p = 0.45). Patients with CPKAP demonstrated significantly larger DGA dimensions compared with controls, including diameter (3.26 ± 0.35 mm vs. 2.59 ± 0.28 mm, p < 0.001), circumference (11.1 ± 1.47 mm vs. 8.65 ± 1.18 mm, p < 0.01) and cross-sectional area (9.14 ± 2.03 mm 2 vs. 5.44 ± 1.55 mm 2 , p < 0.001) (Fig. 2 ). When normalized to the SFA at the level of the DGA origin, the CPKAP group similarly demonstrated larger relative DGA dimensions: diameter ratio (0.46 ± 0.06 vs. 0.41 ± 0.07, p < 0.01), circumference ratio (0.49 ± 0.08 vs. 0.42 ± 0.07, p < 0.01), and area ratio (0.24 ± 0.07 vs. 0.19 ± 0.06, p < 0.05) (Fig. 3 ). No significant differences were observed in the diameters of the SMGA or SLGA between the two groups (SMGA: 2.52 ± 0.16 mm vs. 2.56 ± 0.49 mm, p = 0.59; SLGA: 2.72 ± 0.43 mm vs. 2.42 ± 0.34 mm, p = 0.12). Interobserver measurement reliability was excellent for the DGA (ICC = 0.92) and SFA (ICC = 0.91), moderate for the SLGA (ICC = 0.59), and poor for the SMGA (ICC = 0.28). Discussion In this retrospective, age- and sex-matched case-control study, patients with CPKAP demonstrated significantly larger DGA dimensions compared with knee arthroplasty patients without pain. These differences persisted even after normalization to the SFA, suggesting that vascular remodeling of the genicular arterial circulation may be a distinctive feature in patients with CPKAP. To our knowledge, this is the first study to quantify genicular artery caliber in post-arthroplasty patients, extending the literature on neovascularity in knee OA to this unique subset of patients with persistent pain after knee arthroplasty. Our findings are consistent with prior work in knee OA, where synovial angiogenesis and neovascularity have been implicated in the complex pathogenesis of pain generation. GAE has emerged as a promising minimally invasive treatment option for patients with refractory OA-related pain, and preliminary research suggests potential benefit in patients with CPKAP. To date, non-invasive imaging biomarkers have not been established in this patient population. The present results suggest that enlargement of the DGA may represent one such imaging marker that could help identify potential candidates for GAE. However, the absence of visibly enlarged or easily identifiable genicular arteries on CTA should not preclude attempts at GAE, as hyperemic blush and abnormal neovascularity are often only appreciable during angiography at the time of the procedure. This study has several limitations. First, this was a single-institution, retrospective study with a relatively small sample size, limiting generalizability and precluding detailed subgroup analysis (e.g. patients with total vs. unicompartmental arthroplasty). Second, pain assessment relied on chart review of clinical visits via electronic medical records rather than utilization of standardized scoring instruments. Third, while we controlled for SFA size and excluded subjects with peripheral arterial disease, additional patient factors such as cardiovascular comorbidities, medications, and prosthesis type may influence vascular caliber and were not fully accounted for. Fourth, measurement of smaller caliber vessels on CTA such as the SMGA and SLGA proved more challenging as compared to the relatively larger DGA. This difficulty was reflected in the lower interobserver variability for these arteries and may limit the accuracy in the assessment of these branches. Finally, this study demonstrates association but not causation; whether vascular enlargement is a driver of pain or a secondary phenomenon remains to be determined. Future prospective studies incorporating standardized pain scores, larger and more diverse patient cohorts, and longitudinal follow-up are warranted to validate these findings. Integration of laboratory and imaging biomarkers with clinical outcomes after GAE could further clarify the role of genicular artery caliber in predicting treatment response. Ultimately, a better characterization of how vascular changes evolve in knee arthroplasty patients and how these changes are associated with chronic pain may inform minimally invasive therapeutic strategies for targeted interventions in this population. Conclusions In this retrospective case-control study, patients with CPKAP exhibited significantly larger DGA calibers compared with matched knee arthroplasty controls. These findings suggest that relatively larger genicular artery calibers on CTA in CPKAP patients may serve as a potential imaging biomarker of chronic pain after knee arthroplasty and help inform patient selection for GAE. Prospective and longitudinal studies with standardized pain assessments are needed to validate these results and further define the role of vascular changes in the pathophysiology and treatment of post-arthroplasty pain. Abbreviations CPKAP: Chronic post-knee arthroplasty pain GAE: Genicular artery embolization DGA: Descending genicular artery SMGA: Superior medial genicular artery SLGA: Superior lateral genicular artery SFA: Superficial femoral artery ICC: Intraclass correlation coefficient OA: Osteoarthritis CTA: Computed tomography angiography NCP: No chronic pain References Schwartz AM, Farley KX, Guild GN, Bradbury TL. Projections and Epidemiology of Revision Hip and Knee Arthroplasty in the United States to 2030. J Arthroplasty. 2020 June;35(6 Suppl):S79–85. Shichman I, Roof M, Askew N, Nherera L, Rozell JC, Seyler TM, et al. Projections and Epidemiology of Primary Hip and Knee Arthroplasty in Medicare Patients to 2040-2060. JBJS Open Access. 2023 Feb 28;8(1):e22.00112. Beswick AD, Wylde V, Gooberman-Hill R, Blom A, Dieppe P. What proportion of patients report long-term pain after total hip or knee replacement for osteoarthritis? A systematic review of prospective studies in unselected patients. BMJ Open. 2012 Jan 1;2(1):e000435. Wylde V, Beswick A, Bruce J, Blom A, Howells N, Gooberman-Hill R. Chronic pain after total knee arthroplasty. EFORT Open Rev. 2018 Aug;3(8):461–70. Mapp PI, Walsh DA. Mechanisms and targets of angiogenesis and nerve growth in osteoarthritis. Nat Rev Rheumatol. 2012 July;8(7):390–8. Ashraf S, Mapp PI, Walsh DA. Contributions of angiogenesis to inflammation, joint damage, and pain in a rat model of osteoarthritis. Arthritis Rheum. 2011;63(9):2700–10. Roover AD, Escribano-Núñez A, Monteagudo S, Lories R. Fundamentals of osteoarthritis: Inflammatory mediators in osteoarthritis. Osteoarthritis Cartilage. 2023 Oct 1;31(10):1303–11. Sanchez-Lopez E, Coras R, Torres A, Lane NE, Guma M. Synovial inflammation in osteoarthritis progression. Nat Rev Rheumatol. 2022 May;18(5):258–75. Berenbaum F. Osteoarthritis as an inflammatory disease (osteoarthritis is not osteoarthrosis!). Osteoarthritis Cartilage. 2013 Jan 1;21(1):16–21. Scanzello CR, Goldring SR. The role of synovitis in osteoarthritis pathogenesis. Bone. 2012 Aug 1;51(2):249–57. Kapoor M, Martel-pelletier J, Lajeunesse D, Pelletier J pierre, Fahmi H. Role of proinflammatory cytokines in the pathophysiology of osteoarthritis. Nat Rev Rheumatol. 2011 Jan;7(1):33–42. Taslakian B, Miller LE, Mabud TS, Macaulay W, Samuels J, Attur M, et al. Genicular artery embolization for treatment of knee osteoarthritis pain: Systematic review and meta-analysis. Osteoarthr Cartil Open [Internet]. 2023 June 1 [cited 2025 Sept 22];5(2). Available from: https://www.oarsiopenjournal.com/article/S2665-9131(23)00009-2/fulltext Epelboym Y, Mandell JC, Collins JE, Burch E, Shiang T, Killoran T, et al. Genicular Artery Embolization as a Treatment for Osteoarthritis Related Knee Pain: A Systematic Review and Meta-analysis. Cardiovasc Intervent Radiol. 2023 June 1;46(6):760–9. Femia M, Valenti Pittino C, Fumarola EM, Tramarin M, Papa M, Giurazza F, et al. Genicular Artery Embolization: A New Tool for the Management of Refractory Osteoarthritis-Related Knee Pain. J Pers Med. 2024 July;14(7):686. Chau Y, Roux C, Gonzalez JF, Breuil V, Bernard de Dompsure R, Fontas E, et al. Effectiveness of Geniculate Artery Embolization for Chronic Pain after Total Knee Replacement-A Pilot Study. J Vasc Interv Radiol JVIR. 2023 Oct;34(10):1725–33. Epelboym Y, Guermazi A, Shami U, Chen A. Genicular Artery Embolization in Patients with Chronic Post Knee Arthroplasty Pain: A Retrospective Single Center Analysis. Osteoarthritis Cartilage. 2025 Apr 1;33:S517. Cite Share Download PDF Status: Under Review Version 1 posted Reviewers agreed at journal 18 Feb, 2026 Reviewers invited by journal 09 Feb, 2026 Editor assigned by journal 09 Feb, 2026 First submitted to journal 04 Feb, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8759916","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":588506017,"identity":"8346acd9-f827-4772-8cc3-5e364a101d39","order_by":0,"name":"Bardia Nadim","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA6UlEQVRIiWNgGAWjYBACAyCWSGCwSWCQYGCDiiUwMPAQ1pJGqhYGhsMkaDGXbn5442HO+TyD2w1sD37uOSxv3p7A+OBtG24tlnOOGVskbrtdbHDnALthz7PDhnPOPGA2nItHi8GNBDMJoJbEbTcS2CR4DqQxzpBIYJPmxasl/RtQyzmwFsk/B9LsgVrYf+PXkgOy5QBYizTPAZtEkC3M+LRYzsgpBvoludj+RmKbtMwBm+QZPA+bJeecw63FXCJ9482f2+zyJGckH5N8c0DCdgZ78sEPb8pwa0ECjA3ojFEwCkbBKBgF5AIA5qNWXLALKe0AAAAASUVORK5CYII=","orcid":"https://orcid.org/0000-0001-7809-034X","institution":"Brigham and Women's Hospital","correspondingAuthor":true,"prefix":"","firstName":"Bardia","middleName":"","lastName":"Nadim","suffix":""},{"id":588506018,"identity":"ca9efe7b-4305-42b8-85b4-33e85574f70c","order_by":1,"name":"Rebekah Bihun","email":"","orcid":"","institution":"Brigham and Women's Hospital","correspondingAuthor":false,"prefix":"","firstName":"Rebekah","middleName":"","lastName":"Bihun","suffix":""},{"id":588506019,"identity":"fb8c9b4c-4262-4475-a2d6-16aca3cc55df","order_by":2,"name":"Zhou Lan","email":"","orcid":"","institution":"Brigham and Women's Hospital","correspondingAuthor":false,"prefix":"","firstName":"Zhou","middleName":"","lastName":"Lan","suffix":""},{"id":588506020,"identity":"e93ac3bd-349b-4034-a862-5bc0e674f531","order_by":3,"name":"Antonia Chen","email":"","orcid":"","institution":"The University of Texas Southwestern Medical Center","correspondingAuthor":false,"prefix":"","firstName":"Antonia","middleName":"","lastName":"Chen","suffix":""},{"id":588506021,"identity":"1a4215a2-11cb-4f60-9b07-1ce073d693c7","order_by":4,"name":"Yan Epelboym","email":"","orcid":"","institution":"Brigham and Women's Hospital","correspondingAuthor":false,"prefix":"","firstName":"Yan","middleName":"","lastName":"Epelboym","suffix":""}],"badges":[],"createdAt":"2026-02-02 03:14:53","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8759916/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8759916/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":102596328,"identity":"b58c9f8d-1630-4eaf-93be-81888714918b","added_by":"auto","created_at":"2026-02-13 12:15:50","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":961330,"visible":true,"origin":"","legend":"\u003cp\u003eCoronal computed tomography angiography (CTA) maximum intensity projection (MIP) images of the distal thigh in a patient with chronic post-knee arthroplasty pain (CPKAP) (a) and their age- and sex-matched pain-free control (NCP) (b). The descending genicular artery (DGA) (\u003cem\u003ered arrows\u003c/em\u003e) is visibly enlarged in the CPKAP patient compared with the control\u003c/p\u003e","description":"","filename":"Fig1.png","url":"https://assets-eu.researchsquare.com/files/rs-8759916/v1/0f631ccd0a5afea2ab13d3f9.png"},{"id":102596327,"identity":"3c29a1cc-543c-4bc1-8eec-34bf6b977fb7","added_by":"auto","created_at":"2026-02-13 12:15:50","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":4677679,"visible":true,"origin":"","legend":"\u003cp\u003eSchematic illustration of genicular artery anatomy with comparative descending genicular artery (DGA) measurements between control and chronic post–knee arthroplasty pain (CPKAP) patients, demonstrating significantly larger mean DGA diameter (D), circumference (C), and cross-sectional area (A) in the CPKAP cohort. SFA = superficial femoral artery, SMGA = superior medial genicular artery, SLGA = superior lateral genicular artery, ILGA = inferior lateral genicular artery, IMGA = inferior medial genicular artery. Artwork created using Procreate (Savage Interactive Pty Ltd). Illustration by Rebekah Bihun\u003c/p\u003e","description":"","filename":"Fig2.png","url":"https://assets-eu.researchsquare.com/files/rs-8759916/v1/528b74079bd1944f6a09b0d9.png"},{"id":102596326,"identity":"647afc7b-d6ac-4b9f-8b47-599b8424dbec","added_by":"auto","created_at":"2026-02-13 12:15:50","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":359251,"visible":true,"origin":"","legend":"\u003cp\u003eComparison of descending genicular artery (DGA) dimensions (\u003cem\u003etop row\u003c/em\u003e, a-c) and DGA-to-superficial femoral artery (SFA) ratios (\u003cem\u003ebottom row\u003c/em\u003e, d-f) between age- and sex-matched pairs. Each line connects matched controls (NCP in blue circles) and patients with chronic post-knee arthroplasty pain (CPKAP in red circles). Colored circles represent individual patient measurements and white diamonds denote group means ± 95% confidence intervals. Patients with CPKAP consistently demonstrate larger DGA dimensions and increased DGA:SFA ratios compared with matched controls\u003c/p\u003e","description":"","filename":"Fig3.png","url":"https://assets-eu.researchsquare.com/files/rs-8759916/v1/c4ca16a070ef1ef025264b21.png"},{"id":102596329,"identity":"2c3bccdf-1496-46ef-83b6-edf47b3ff4f3","added_by":"auto","created_at":"2026-02-13 12:15:58","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":7004650,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8759916/v1/f08ff46f-0f48-4b8b-b868-3d42c8771f11.pdf"}],"financialInterests":"","formattedTitle":"Genicular Artery Caliber in Patients with Chronic Pain after Knee Arthroplasty: An Age-Matched Case-Control Study","fulltext":[{"header":"Background","content":"\u003cp\u003eKnee arthroplasties are among the most frequently performed orthopedic surgeries worldwide. They are primarily performed for patients with refractory pain from knee osteoarthritis (OA). Epidemiological studies project a steady growth in the volume of these surgeries, with the number of primary total knee arthroplasty in the Medicare population alone predicted to reach upwards of 1.2\u0026nbsp;million by 2040 and 2.9\u0026nbsp;million by 2060 (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e). While knee arthroplasties generally have favorable outcomes, chronic pain following knee arthroplasty (persistent beyond 3\u0026ndash;6 months after surgery) remains relatively common, affecting approximately 20% of patients (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e). Chronic post-knee arthroplasty pain (CPKAP) adversely affects function, quality of life, and patient satisfaction, and often lacks a single surgically correctable cause once infection, loosening, malalignment, and instability are excluded (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e). Given the high prevalence of knee arthroplasty and the substantial subset of patients who experience CPKAP, understanding the etiologies of this pain is critical.\u003c/p\u003e \u003cp\u003eA growing body of work suggests that synovial inflammation, pathologic neovascularization, and nociceptive innervation contribute to the complex pathogenesis of pain in knee OA (\u003cspan additionalcitationids=\"CR6 CR7 CR8 CR9 CR10\" citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e). The basic premise is that inflammation induces angiogenesis, which facilitates structural remodeling and proliferation of unmyelinated sensory nerve fibers, thereby contributing to the persistence and amplification of pain (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e). Genicular artery embolization (GAE) has emerged as a minimally invasive endovascular technique to target this process in knee OA with the intent to devascularize hyperemic synovium and modulate inflammatory pain signaling. Multiple systematic reviews and meta-analyses have reported clinically meaningful long-term pain relief and functional gains in patients with knee OA following GAE (\u003cspan additionalcitationids=\"CR13\" citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eHowever, the potential vascular changes associated with CPKAP remain less well characterized compared to the growing body of literature in the knee OA population. Early interventional experience indicates that GAE can be performed safely in post-arthroplasty patients with persistent pain. Early evidence suggests potential benefit of GAE in post-arthroplasty patients, with a small retrospective study by Epelboym et al. demonstrating short-term pain improvement at 1 and 3 months and a pilot study by Chau et al. showing sustained pain reduction at 12 months, though both studies were limited by small sample sizes and the overall literature remains sparse (\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eCollectively, these preliminary findings of symptomatic improvement following GAE in CPKAP suggest that CPKAP may share, at least in part, a common vascular target with painful knee OA. Prior research has demonstrated positive correlations between knee OA severity and the caliber of the descending genicular artery (DGA) on computed tomographic angiography (CTA). While this is also a preliminary finding, it is important to explore whether patients with CPKAP demonstrate changes in genicular artery caliber as compared to controls who have undergone knee arthroplasty. Accordingly, the aim of this study was to retrospectively evaluate genicular artery caliber on CTA in patients with CPKAP compared with pain-free arthroplasty controls.\u003c/p\u003e"},{"header":"Materials \u0026 Methods","content":"\u003cp\u003e Institutional review board approval was obtained with a waiver of informed consent, in compliance with HIPAA regulations. We conducted a retrospective review of 22 knee arthroplasty patients with lower extremity CTA examinations performed at our institution from January 2024 to August 2024. Patients were eligible if they had undergone prior knee arthroplasty and had corresponding clinical documentation in the electronic medical record regarding the presence or absence of chronic postoperative knee pain (defined as \u0026ge;\u0026thinsp;3 months after surgery) in the operated knee. Patients who underwent CTA for traumatic indications or demonstrated extensive atherosclerotic calcifications on imaging were excluded. Among the included patients, one patient in the CPKAP group and one patient in the control group had undergone unicompartmental (partial) knee arthroplasty rather than total knee arthroplasty; these patients were not matched within the same case\u0026ndash;control pair.\u003c/p\u003e \u003cp\u003ePatients were stratified into two groups: those with CPKAP and those with no chronic pain (NCP). For comparison, a case-control methodology was used in which patients with CPKAP were matched to NCP patients by age and sex. Demographic variables, including age, sex, body mass index (BMI), and number of days between arthroplasty and CTA, as well as imaging features, including measurements of the superficial femoral artery (SFA), descending genicular artery (DGA), superior medial genicular artery (SMGA), and superior lateral genicular artery (SLGA), were collected and analyzed. Arterial dimensions were obtained using multiplanar reformats orthogonal to the vessel axis and included vessel diameter, circumference, and cross-sectional area (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). The SFA was measured at the level of the DGA origin, enabling calculation of a DGA-to-SFA ratio to evaluate the relative caliber of the DGA compared to its parent vessel. Two independent readers (BN and YE) performed all measurements.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eStatistical analyses were conducted using SAS software (SAS Institute, Cary, NC). Paired \u003cem\u003et\u003c/em\u003e-tests were used to compare cases and matched controls with statistical significance set at p\u0026thinsp;\u0026lt;\u0026thinsp;0.05. Interobserver agreement between the two readers was assessed using intraclass correlation coefficients (ICC). Analyses of the averaged measurements from both readers were used for group comparisons.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eA total of 22 patients were included, comprising 11 with CPKAP and 11 age- and sex-matched knee arthroplasty controls without pain. Of the 22 patients included, two had undergone unicompartmental knee arthroplasty (one in the CPKAP group and one in the control group). The mean age was 64.0\u0026thinsp;\u0026plusmn;\u0026thinsp;6.1 years in the CPKAP group (range\u0026thinsp;=\u0026thinsp;53\u0026ndash;73) and 67.2\u0026thinsp;\u0026plusmn;\u0026thinsp;6.0 years in the NCP group (range\u0026thinsp;=\u0026thinsp;64\u0026ndash;78). Females accounted for 73% (8/11) of each cohort. The mean BMI was 32.2\u0026thinsp;\u0026plusmn;\u0026thinsp;5.8 kg/m\u003csup\u003e2\u003c/sup\u003e in the CPKAP group and 30.1\u0026thinsp;\u0026plusmn;\u0026thinsp;6.5 kg/m\u003csup\u003e2\u003c/sup\u003e in the NCP group (p\u0026thinsp;=\u0026thinsp;0.49). The average interval between arthroplasty and CTA was 2070\u0026thinsp;\u0026plusmn;\u0026thinsp;2730 days for the CPKAP group and 2732\u0026thinsp;\u0026plusmn;\u0026thinsp;1646 days for the NCP group (p\u0026thinsp;=\u0026thinsp;0.45).\u003c/p\u003e \u003cp\u003ePatients with CPKAP demonstrated significantly larger DGA dimensions compared with controls, including diameter (3.26\u0026thinsp;\u0026plusmn;\u0026thinsp;0.35 mm vs. 2.59\u0026thinsp;\u0026plusmn;\u0026thinsp;0.28 mm, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), circumference (11.1\u0026thinsp;\u0026plusmn;\u0026thinsp;1.47 mm vs. 8.65\u0026thinsp;\u0026plusmn;\u0026thinsp;1.18 mm, p\u0026thinsp;\u0026lt;\u0026thinsp;0.01) and cross-sectional area (9.14\u0026thinsp;\u0026plusmn;\u0026thinsp;2.03 mm\u003csup\u003e2\u003c/sup\u003e vs. 5.44\u0026thinsp;\u0026plusmn;\u0026thinsp;1.55 mm\u003csup\u003e2\u003c/sup\u003e, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). When normalized to the SFA at the level of the DGA origin, the CPKAP group similarly demonstrated larger relative DGA dimensions: diameter ratio (0.46\u0026thinsp;\u0026plusmn;\u0026thinsp;0.06 vs. 0.41\u0026thinsp;\u0026plusmn;\u0026thinsp;0.07, p\u0026thinsp;\u0026lt;\u0026thinsp;0.01), circumference ratio (0.49\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08 vs. 0.42\u0026thinsp;\u0026plusmn;\u0026thinsp;0.07, p\u0026thinsp;\u0026lt;\u0026thinsp;0.01), and area ratio (0.24\u0026thinsp;\u0026plusmn;\u0026thinsp;0.07 vs. 0.19\u0026thinsp;\u0026plusmn;\u0026thinsp;0.06, p\u0026thinsp;\u0026lt;\u0026thinsp;0.05) (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). No significant differences were observed in the diameters of the SMGA or SLGA between the two groups (SMGA: 2.52\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16 mm vs. 2.56\u0026thinsp;\u0026plusmn;\u0026thinsp;0.49 mm, p\u0026thinsp;=\u0026thinsp;0.59; SLGA: 2.72\u0026thinsp;\u0026plusmn;\u0026thinsp;0.43 mm vs. 2.42\u0026thinsp;\u0026plusmn;\u0026thinsp;0.34 mm, p\u0026thinsp;=\u0026thinsp;0.12). Interobserver measurement reliability was excellent for the DGA (ICC\u0026thinsp;=\u0026thinsp;0.92) and SFA (ICC\u0026thinsp;=\u0026thinsp;0.91), moderate for the SLGA (ICC\u0026thinsp;=\u0026thinsp;0.59), and poor for the SMGA (ICC\u0026thinsp;=\u0026thinsp;0.28).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eIn this retrospective, age- and sex-matched case-control study, patients with CPKAP demonstrated significantly larger DGA dimensions compared with knee arthroplasty patients without pain. These differences persisted even after normalization to the SFA, suggesting that vascular remodeling of the genicular arterial circulation may be a distinctive feature in patients with CPKAP. To our knowledge, this is the first study to quantify genicular artery caliber in post-arthroplasty patients, extending the literature on neovascularity in knee OA to this unique subset of patients with persistent pain after knee arthroplasty.\u003c/p\u003e \u003cp\u003eOur findings are consistent with prior work in knee OA, where synovial angiogenesis and neovascularity have been implicated in the complex pathogenesis of pain generation. GAE has emerged as a promising minimally invasive treatment option for patients with refractory OA-related pain, and preliminary research suggests potential benefit in patients with CPKAP. To date, non-invasive imaging biomarkers have not been established in this patient population. The present results suggest that enlargement of the DGA may represent one such imaging marker that could help identify potential candidates for GAE. However, the absence of visibly enlarged or easily identifiable genicular arteries on CTA should not preclude attempts at GAE, as hyperemic blush and abnormal neovascularity are often only appreciable during angiography at the time of the procedure.\u003c/p\u003e \u003cp\u003eThis study has several limitations. First, this was a single-institution, retrospective study with a relatively small sample size, limiting generalizability and precluding detailed subgroup analysis (e.g. patients with total vs. unicompartmental arthroplasty). Second, pain assessment relied on chart review of clinical visits via electronic medical records rather than utilization of standardized scoring instruments. Third, while we controlled for SFA size and excluded subjects with peripheral arterial disease, additional patient factors such as cardiovascular comorbidities, medications, and prosthesis type may influence vascular caliber and were not fully accounted for. Fourth, measurement of smaller caliber vessels on CTA such as the SMGA and SLGA proved more challenging as compared to the relatively larger DGA. This difficulty was reflected in the lower interobserver variability for these arteries and may limit the accuracy in the assessment of these branches. Finally, this study demonstrates association but not causation; whether vascular enlargement is a driver of pain or a secondary phenomenon remains to be determined.\u003c/p\u003e \u003cp\u003eFuture prospective studies incorporating standardized pain scores, larger and more diverse patient cohorts, and longitudinal follow-up are warranted to validate these findings. Integration of laboratory and imaging biomarkers with clinical outcomes after GAE could further clarify the role of genicular artery caliber in predicting treatment response. Ultimately, a better characterization of how vascular changes evolve in knee arthroplasty patients and how these changes are associated with chronic pain may inform minimally invasive therapeutic strategies for targeted interventions in this population.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eIn this retrospective case-control study, patients with CPKAP exhibited significantly larger DGA calibers compared with matched knee arthroplasty controls. These findings suggest that relatively larger genicular artery calibers on CTA in CPKAP patients may serve as a potential imaging biomarker of chronic pain after knee arthroplasty and help inform patient selection for GAE. Prospective and longitudinal studies with standardized pain assessments are needed to validate these results and further define the role of vascular changes in the pathophysiology and treatment of post-arthroplasty pain.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003e\u003cstrong\u003eCPKAP:\u0026nbsp;\u003c/strong\u003eChronic post-knee arthroplasty pain\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eGAE:\u003c/strong\u003e Genicular artery embolization\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDGA:\u003c/strong\u003e Descending genicular artery\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSMGA:\u003c/strong\u003e Superior medial genicular artery\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSLGA:\u003c/strong\u003e Superior lateral genicular artery\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSFA:\u0026nbsp;\u003c/strong\u003eSuperficial femoral artery\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eICC:\u003c/strong\u003e Intraclass correlation coefficient\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eOA:\u003c/strong\u003e Osteoarthritis\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCTA:\u0026nbsp;\u003c/strong\u003eComputed tomography angiography\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eNCP:\u003c/strong\u003e No chronic pain\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eSchwartz AM, Farley KX, Guild GN, Bradbury TL. Projections and Epidemiology of Revision Hip and Knee Arthroplasty in the United States to 2030. J Arthroplasty. 2020 June;35(6 Suppl):S79\u0026ndash;85. \u003c/li\u003e\n\u003cli\u003eShichman I, Roof M, Askew N, Nherera L, Rozell JC, Seyler TM, et al. Projections and Epidemiology of Primary Hip and Knee Arthroplasty in Medicare Patients to 2040-2060. JBJS Open Access. 2023 Feb 28;8(1):e22.00112. \u003c/li\u003e\n\u003cli\u003eBeswick AD, Wylde V, Gooberman-Hill R, Blom A, Dieppe P. What proportion of patients report long-term pain after total hip or knee replacement for osteoarthritis? A systematic review of prospective studies in unselected patients. BMJ Open. 2012 Jan 1;2(1):e000435. \u003c/li\u003e\n\u003cli\u003eWylde V, Beswick A, Bruce J, Blom A, Howells N, Gooberman-Hill R. Chronic pain after total knee arthroplasty. EFORT Open Rev. 2018 Aug;3(8):461\u0026ndash;70. \u003c/li\u003e\n\u003cli\u003eMapp PI, Walsh DA. Mechanisms and targets of angiogenesis and nerve growth in osteoarthritis. Nat Rev Rheumatol. 2012 July;8(7):390\u0026ndash;8. \u003c/li\u003e\n\u003cli\u003eAshraf S, Mapp PI, Walsh DA. Contributions of angiogenesis to inflammation, joint damage, and pain in a rat model of osteoarthritis. Arthritis Rheum. 2011;63(9):2700\u0026ndash;10. \u003c/li\u003e\n\u003cli\u003eRoover AD, Escribano-N\u0026uacute;\u0026ntilde;ez A, Monteagudo S, Lories R. Fundamentals of osteoarthritis: Inflammatory mediators in osteoarthritis. Osteoarthritis Cartilage. 2023 Oct 1;31(10):1303\u0026ndash;11. \u003c/li\u003e\n\u003cli\u003eSanchez-Lopez E, Coras R, Torres A, Lane NE, Guma M. Synovial inflammation in osteoarthritis progression. Nat Rev Rheumatol. 2022 May;18(5):258\u0026ndash;75. \u003c/li\u003e\n\u003cli\u003eBerenbaum F. Osteoarthritis as an inflammatory disease (osteoarthritis is not osteoarthrosis!). Osteoarthritis Cartilage. 2013 Jan 1;21(1):16\u0026ndash;21. \u003c/li\u003e\n\u003cli\u003eScanzello CR, Goldring SR. The role of synovitis in osteoarthritis pathogenesis. Bone. 2012 Aug 1;51(2):249\u0026ndash;57. \u003c/li\u003e\n\u003cli\u003eKapoor M, Martel-pelletier J, Lajeunesse D, Pelletier J pierre, Fahmi H. Role of proinflammatory cytokines in the pathophysiology of osteoarthritis. Nat Rev Rheumatol. 2011 Jan;7(1):33\u0026ndash;42. \u003c/li\u003e\n\u003cli\u003eTaslakian B, Miller LE, Mabud TS, Macaulay W, Samuels J, Attur M, et al. Genicular artery embolization for treatment of knee osteoarthritis pain: Systematic review and meta-analysis. Osteoarthr Cartil Open [Internet]. 2023 June 1 [cited 2025 Sept 22];5(2). Available from: https://www.oarsiopenjournal.com/article/S2665-9131(23)00009-2/fulltext\u003c/li\u003e\n\u003cli\u003eEpelboym Y, Mandell JC, Collins JE, Burch E, Shiang T, Killoran T, et al. Genicular Artery Embolization as a Treatment for Osteoarthritis Related Knee Pain: A Systematic Review and Meta-analysis. Cardiovasc Intervent Radiol. 2023 June 1;46(6):760\u0026ndash;9. \u003c/li\u003e\n\u003cli\u003eFemia M, Valenti Pittino C, Fumarola EM, Tramarin M, Papa M, Giurazza F, et al. Genicular Artery Embolization: A New Tool for the Management of Refractory Osteoarthritis-Related Knee Pain. J Pers Med. 2024 July;14(7):686. \u003c/li\u003e\n\u003cli\u003eChau Y, Roux C, Gonzalez JF, Breuil V, Bernard de Dompsure R, Fontas E, et al. Effectiveness of Geniculate Artery Embolization for Chronic Pain after Total Knee Replacement-A Pilot Study. J Vasc Interv Radiol JVIR. 2023 Oct;34(10):1725\u0026ndash;33. \u003c/li\u003e\n\u003cli\u003eEpelboym Y, Guermazi A, Shami U, Chen A. Genicular Artery Embolization in Patients with Chronic Post Knee Arthroplasty Pain: A Retrospective Single Center Analysis. Osteoarthritis Cartilage. 2025 Apr 1;33:S517. \u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":true,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"cvir-endovascular","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"cire","sideBox":"Learn more about [CVIR Endovascular](https://www.springer.com/journal/42155)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/cire/default.aspx","title":"CVIR Endovascular","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Genicular artery embolization, GAE, knee osteoarthritis, knee pain, chronic post-knee arthroplasty pain","lastPublishedDoi":"10.21203/rs.3.rs-8759916/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8759916/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground:\u003c/h2\u003e \u003cp\u003eChronic post\u0026ndash;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.\u003c/p\u003e\u003ch2\u003eMaterials and Methods:\u003c/h2\u003e \u003cp\u003e 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.\u003c/p\u003e\u003ch2\u003eResults:\u003c/h2\u003e \u003cp\u003eTwenty-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\u0026thinsp;\u0026gt;\u0026thinsp;0.05). CPKAP patients had larger DGA diameters (3.26\u0026thinsp;\u0026plusmn;\u0026thinsp;0.35 vs. 2.59\u0026thinsp;\u0026plusmn;\u0026thinsp;0.28 mm), circumferences (11.1\u0026thinsp;\u0026plusmn;\u0026thinsp;1.47 vs. 8.65\u0026thinsp;\u0026plusmn;\u0026thinsp;1.18 mm), and cross-sectional areas (9.14\u0026thinsp;\u0026plusmn;\u0026thinsp;2.03 vs. 5.44\u0026thinsp;\u0026plusmn;\u0026thinsp;1.55 mm\u0026sup2;; all p\u0026thinsp;\u0026lt;\u0026thinsp;0.01), including increased DGA:SFA ratios. No differences were observed for SMGA or SLGA. ICCs were excellent for DGA and SFA.\u003c/p\u003e\u003ch2\u003eConclusions:\u003c/h2\u003e \u003cp\u003eCPKAP patients demonstrate enlarged DGA caliber compared with pain-free arthroplasty controls, suggesting pathologic neovascular changes and supporting further evaluation of GAE.\u003c/p\u003e","manuscriptTitle":"Genicular Artery Caliber in Patients with Chronic Pain after Knee Arthroplasty: An Age-Matched Case-Control Study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-02-13 12:15:45","doi":"10.21203/rs.3.rs-8759916/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewerAgreed","content":"","date":"2026-02-18T14:27:11+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-02-09T18:30:25+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-02-09T13:14:13+00:00","index":"","fulltext":""},{"type":"submitted","content":"CVIR Endovascular","date":"2026-02-04T13:14:28+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"cvir-endovascular","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"cire","sideBox":"Learn more about [CVIR Endovascular](https://www.springer.com/journal/42155)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/cire/default.aspx","title":"CVIR Endovascular","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"54d9e129-5160-4d9b-a30f-50bf808d836a","owner":[],"postedDate":"February 13th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-05-06T13:52:18+00:00","versionOfRecord":[],"versionCreatedAt":"2026-02-13 12:15:45","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8759916","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8759916","identity":"rs-8759916","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}