Effect Of Knee Soft Tissue Relaxation On Patient Satisfaction After Total Knee Arthroplasty

BackgroundTotal knee arthroplasty(TKA)is recognized as the most direct and effective surgical method for the treatment of advanced knee osteoarthritis(KOA).Appropriate knee relaxation is an important factor affecting the effect of TKA.Appropriate intraoperative soft tissue balance will affect knee relaxation due to patient heterogeneity in the middle and long term after TKA.At present,the impact of knee relaxation on patient satisfaction remains to be studied.ObjectiveThe purpose of this study is to explore the impact of knee soft tissue relaxation on patient satisfaction in the medium and long-term follow-up after total knee arthroplasty,and to provide basis for surgeons to evaluate knee relaxation more than 5 years after TKA.MethodsA total of 110 patients who underwent primary unilateral total knee arthroplasty in the First Affiliated Hospital of Zhengzhou University and were followed up for 5-10 years were selected to take stress X-ray films and measure bilateral knee joint coronal and sagittal relaxation by different methods.According to the coronal laxity grouping,the knee laxity was divided into A1 group(≥0° and ≤4°,n=22),A2 group(>4° and ≤6°,n=31),A3 group(>6°and≤9°,n=24),A4 group(>9°,n=33).The patients were divided into group B1(≤-3°,n=27),group B2(>-3° and ≤0°,n=33),group B3(>0° and ≤3.5°,n=27),group B4(>3.5°,n=23).According to sagittal relaxation,the knees were divided into a1 group(>0 mm and ≤5 mm,n=21),a2 group(>5 mm and ≤7 mm,n=27),a3 group(>7mm and ≤9 mm,n=36),group a4(>9 mm,n=26).According to the difference in laxity between knees,they were divided into group b1(≤-1.5mm,n=25),group b2(>-1.5mm and ≤-0.7mm,n=28),group b3(>-0.7mm and ≤0.7 mm,n=31),group b4(>0.7mm,n=26).Knee function was evaluated according to OKS score and modified Lysholm score,and the range of soft tissue laxity and the range of laxity difference between knees with the highest patient satisfaction were found.Results1.There were no significant differences in baseline data such as age,height,and body mass index among the groups(P>0.05).2.Grouped according to the coronal laxity of the knee joint on the operative side.There was a significant difference in the OKS score among the groups(F=5.121,P=0.004<0.05),among which the lowest score was group A3(6,9]°,with a score of 17.92±0.84;there was a significant difference in the modified Lysholm score among the groups(F=4.786,P=0.008<0.05),the highest score was group A3(6,9]°,with a score of 85.87±4.29.There was no significant difference between the two scores of group A2(4,6]° and A3,with a score of OKS 18.41±0.76,respectively(P>0.05).Modified lysholm85.48±3.50.3.Grouped by the difference in coronal laxity of both knees.There was a significant difference in the OKS score among the groups(F=17.873,P=0.000<0.05),and the lowest score was group B2(-3,0]°,with a score of 17.98±0.72;there was a significant difference in the modified Lysholm score among the groups(F=10.796,P=0.000<0.05),the highest score was group B2(-3,0]°,with a score of 86.92±3.81.There was no significant difference between the two scores of group B3(0,3.5]° and B2(P>0.05),and the scores were OKS 18.24±3.81,respectively.0.95,modified Lysholm 85.68±4.14.4.Grouped by sagittal laxity of the knee joint on the operative side.There was a significant difference in the OKS score among the groups(F=10.866,P=0.000<0.05),and the lowest score was the a3(7,9]mm group,with a score of 17.97±0.91;there was a significant difference in the modified Lysholm score among the groups(F=26.575).,P=0.000<0.05),the highest score was a3(7,9]mm group,with a score of 86.78±2.82.There was no significant difference between a2[5,7)mmOKS score and a3(P>0.05),with a score of 18.37±0.97.5.Grouped by the difference in sagittal laxity of both knees.There was no significant difference in the OKS score between the groups(F=0.827,P=0.482>0.05);there was a significant difference in the modified Lysholm score between the groups(F=3.101,P=0.030<0.05),and the highest score was b3(-0.7,0.7]mm group,the score was 85.04±3.84.There was no significant difference between group b2(-1.5,-0.7]mm modified Lysholm score and b3(P>0.05),the score was 84.19±3.45.Conclusion1.The coronal soft tissue laxity range of the knee joint with the highest patient satisfaction in the medium and long-term follow-up of the initial unilateral TKA is 6-9°,and 4-6° can also obtain good satisfaction.2.The sagittal soft tissue laxity of the knee joint with the highest patient satisfaction in the medium and long-term follow-up of the initial unilateral TKA is 7-9mm,and 5-7mm can also obtain good satisfaction.3.The smaller the difference in the laxity between the knees in the patients with primary unilateral TKA,the higher the patient satisfaction;when there is a difference in the laxity between the knees,the laxity of the knee joint on the operative side is less than that on the contralateral side,which is more satisfactory to the patient,but it is necessary to ensure that the operative side The knee joint is straight and unobstructed.