Difference Between Screw Cement Filling And Adequate Osteotomy Thick Liner For Primary Total Knee Arthroplasty In Patients With Rand Ⅱb Tibial Defects

Background:The effectiveness of two treatment options,screw-cement fill and adequate osteotomy with a thick liner,in treating patients with Rand IIb tibial defects(tibial plateau defects to a depth of 5 to 10 millimeters)in primary total knee arthroplasty(TKA)has not yet been demonstrated.Therefore,we performed a retrospective study to evaluate the differences between these two treatments.Methods:We retrospectively analyzed patients who underwent primary TKA for Rand IIb tibial plateau defects from 2015 to 2020 from a department database.Patients were categorized into the screw-cement and thick liner groups based on the different options used to repair tibial defects.We evaluated Knee Society Score,range of motion(ROM),Insall-Salvati index(ISI),and Forgotten Joint Score(FJS)in both groups.We also compared differences in prosthesis survival,stiffness,myasthenia,and joint clicking between the two groups at mean two years postoperatively(range,2 to 2.3).A power analysis was performed on the number of cases in the cohort.Results:Postoperative femur-tibia mechanical axis(FTMA)correction was significantly higher in the screw-cement group than in the thick-liner group: 18.8(±5.6°)vs.15.4(±5.9°)(P<0.01);At mean 2 years after surgery,the American Knee Society Functional Score improvement values were higher in the thick-liner group than in the screw-cement group: 36.3(±12.4)vs 42.4(±16.4)(P=0.05).Postoperative ISI scores were 0.95(±0.12)points in the screw-cement group and 0.89(±0.13)points in the-thick liner group(P=0.03).There were no statistically significant differences in the Knee Society Clinical Score,ROM,FJS,stiffness,myasthenia,joint clicking,and revision rate.Conclusion:The results of this study showed no significant difference in clinical outcomes between the two reconstruction strategies of the screw cement fill technique and the adequate osteotomy and thick liner technique for Rand IIb tibial plateau defects.However,in patients who have FTMA deformities greater than 20° or in younger patients who need to preserve bone volume,we recommend the screw cement filling technique to ensure stable postoperative results and to prepare these patients for possible later surgery.