Application Of MRI Osteoarthritis Knee Score In Genicular Artery Embolization For Knee Osteoarthritis

Objective To investigate the efficacy and safety of genicular arterial embolization in the treatment of secondary pain in patients with mild to moderate and severe knee osteoarthritis,and to explore the application of MRI osteoarthritis knee score in predicting the efficacy of genicular arterial embolization.Material and methods The first part is a single-center prospective study.From October2020 to February 2022,33 patients(37 affected knees)with mild to severe radiographic knee osteoarthritis who had pain for more than a year and patients with moderate to severe pain,and did not respond to conservative treatment were recruited prospectively.Knee pain,stiffness,and symptoms were evaluated by visual analogue scale(VAS)and Western Ontario and Mc Master Universities Arthritis Index(WOMAC)at baseline and 1 day,1 week,1 month,3 months,6months,and 12 months after the procedure.The plain radiograph and MR image characteristics were evaluated by Kellgeren-Lawrance(K-L)grade and the Magnetic Resonance Imaging Osteoarthritis Knee Score(MOAKS).Polyvinyl alcohol particles of 150-350 μm were used for selective genicular artery embolization.The primary end point was VAS and WOMAC score reduction,technical success,and safety at 12 months after procedure.The second part is a retrospective analysis of 44 patients(51 affected knees)who underwent genicular arterial embolization for knee osteoarthritis between October 2020 and August 2022,and evaluated the features of plain film and MR images within one week before the procedure.The MR imaging characteristics of the knee including bone marrow lesions,cartilage loss,osteophytes,Hoffa’s synovitis,effusion synovitis,and meniscal extrusion,were evaluated by Magnetic resonance osteoarthritis knee score(MOAKS).The Western Ontario and Mc Master Universities Osteoarthritis Index(WOMAC)questionnaire was used to assess each knee at baseline and 1-day,7 days,and 1,3,and 6 months after procedure.The value of K-L grade and MR imaging features in predicting the therapeutic effect of genicular artery embolization was estimated according to the patient’s receiver characteristic curve.Results The first part,we enrolled 33 patients(37 affected knees).According to the Kellgren-Lawrence grade,the patients were divided into two groups for treatment,moderate osteoarthritis group(n = 28,K-L grade 2-3)and severe osteoarthritis group(n = 9,K-L grade 4).The age,body mass index,and baseline VAS score were not significantly different between the two groups.The mean VAS scores of the mild-to-moderate group were significantly reduced at 1day,1 week,1 month,3 months,6 months and 12 months after the procedure(baseline 6.6 and postoperative 3.9,3.2,2.9,3.0,2.8,and 3.0,all P= 0.001).The mean VAS scores in the severe group were also get reduction at 1 day,1 week,1 month,3 months,6 months and 12 months(baseline 7.3,postoperative 4.9,4.0,4.0,4.0,4.2,and 4.4,all P= 0.001).All participants underwent genicular artery embolization with a 100% technical success rate and no procedure-related major adverse events.The second part,we analyzed the data of 44 patients(51 affected knees)who underwent genicular artery embolization.Seven knees for K-L 2,30 knees for K-L 3,and 14 knees for K-L 4,we follow-up the patients for at least 6 months.All patients successfully selectively embolized2-6 target arteries,and all patients were followed up as planned and obtained WOMAC score questionnaire.The results showed that the WOMAC pain scores of all patients decreased by an average of 4.6 points(38.1%),6.1 points(49.6%),6.5 points(53.7%),6.0 points(49.6%),6.3points(52.1%)at 1 day,7 days,1 month,3 months,and 6 months after procedure,respectively,compared with those before operation.In the prediction of GAE benefits,the areas under the ROC curve of K-L grade,bone marrow lesions,cartilage loss area,cartilage full-thickness loss,osteophyte,Hoffa’s synovitis,effusion synovitis and meniscus extrusion were respectively 0.810,0.856,0.812,0.813,0.646,0.672,0.653,and 0.827.GAE response was correlated with K-L grade,bone marrow lesions,cartilage loss area,cartilage full-thickness loss,and degree of meniscus extrusion(all P<0.001).Among them,the best predictive performance was full-thickness cartilage defect.Conclusion Genicular artery embolization has good short-term curative effect and is safe and feasible in the treatment of secondary pain in patients with mild to severe knee osteoarthritis,and it provides a new treatment option for patients with knee pain secondary to osteoarthritis.Among mild-to-severe KOA patients treated with GAE,high K-L grade,heavy full-thickness cartilage defect,heavy bone marrow lesion,large cartilage defect,and heavy meniscus extrusion were associated with less pain relief at 6 months after GAE.