Effect Of Lower Limb Force Line Correction On Early Knee Function After Total Knee Arthroplasty In Knee Osteoarthritis Patients With Varus Deformity

Objective:To explore the effect of lower limb force line correction on early knee function after total knee arthroplasty(TKA)in knee osteoarthritis patients with preoperative varus knee deformity,and provide some basis for the correction of lower limb force line in such patients during total knee arthroplasty.Methods:Clinical data of patients with knee osteoarthritis with varus deformity who underwent unilateral TKA by the same surgeon in the Second Hospital of Shanxi Medical University from January 2021 to October 2022 were retrospectively analyzed.The hipknee-ankle Angle(HKA Angle)was measured on the full-length X-ray film of both lower limbs before and after operation.The Hospital for Special Surgery Knee score(HSS score)and range of motion(ROM)of the knee were obtained through admission examination and follow-up.According to the postoperative HKA,the patients were divided into neutral group(177° < HKA≤180°),mild residual varus group(174° <HKA≤177°)and severe residual varus group(HKA≤174°).The preoperative and postoperative HSS scores and ROM of each group,and the differences of postoperative HSS scores and ROM among the three groups were compared and statistically analyzed.Results:After TKA,HKA improved from 170.2±4.6° to 177.4±2.5°,HSS score improved from 59.3±4.3 to 85.9±4.1,ROM improved from 88.9±9.9° to 110.5±10.1°.The mean postoperative HSS score was 85.3±3.0 in neutral group,89.0±4.0 in mild residual varus group and 82.0±2.6 in severe residual varus group.The mean postoperative ROM was110.1±10.6° in neutral group,113.8±9.6° in mild residual varus group and 105.6±7.7°in severe residual varus group.After statistical analysis,the HSS score of the mild residual varus group was higher than that of the neutral group and the severe residual varus group,the HSS score of the neutral group was higher than that of the severe residual varus group,and the ROM of the neutral group and the mild residual varus group was higher than that of the severe residual varus group,the difference was statistically significant.There was no significant difference in postoperative ROM between the neutral group and the mild residual varus group.Conclusion:TKA can effectively improve the lower limb force line and early knee function in knee osteoarthritis patients with varus deformity.In the short-term follow-up of 86 patients,mild residual varus can obtain better early knee function than neutral position,but severe residual varus should be avoided.