Analysis Of Lower Limb Alignment Before And After Oxford Unicompartmental Knee Arthroplasty And Study On The Influencing Factors Of Postoperative Lower Limb Alignment

Objective:To retrospectively study the lower limb alignment of patients before and after Oxford unicompartmental knee arthroplasty(OUKA);and the factors affecting the lower limb alignment of patients after OUKA were explored.Methods:To retrospectively study 71 patients(90 knees)who were treated with OUKA in the Second Hospital of Shanxi Medical University from January 2019 to December 2019.including 25 males(30 knees)and 46 females(60 knees).The age ranged from 50 to 84 years,with an average of(64.75±7.21)years.The BMI ranged from 16.81 to 35.38 kg/㎡,with an average of(26.24±3.96)kg/㎡.The preoperative and postoperative imaging data were collected,and the lower limb alignment were analyzed.Patients were divided into two groups according to the postoperative HKA.Group A was the normal group(-3° ≤HKA ≤ 3°);Group B was the varus group(3°<HKA).The age,sex,BMI,preoperative HKA,preoperative LDFA,preoperative MPTA,preoperative JLCA,thickness of tinsert,femoral prosthesis varus or valgus angle,femoral prosthesis flexion or extension angle,tibial prosthesis varus or valgus angle and tibial prosthesis posterior angle were analyzed to explore the influencing factors of postoperative HKA.Results:The mean preoperative HKA was(7.98±3.28)° and postoperative HKA was(3.54±2.01)°,the mean change in HKA was(4.43±2.18)°.There were significant differences in the preoperative HKA,preoperative LDFA,preoperative MPTA and preoperative JLCA between group A and group B(P < 0.05).There were no significant differences in the age,sex,BMI,operative side,thickness of tinsert,femoral prosthesis varus or valgus angle,femoral prosthesis flexion or extension angle,tibial prosthesis varus or valgus angle and tibial prosthesis posterior angle between the two groups.The results of multiple linear regression showed that preoperative LDFA,MPTAand JLCA were the influencing factors of HKA after OUKA(P < 0.05).Conclusion:The lower limb alignment varus deformity is common in AMOA patients.After OUKA,the varus degree of lower limb alignment is mild varus.The larger preoperative LDFA,JLCA and the smaller preoperative MPTA will increase the varus degree of postoperative lower limb alignment.In order to the postoperative lower limb alignment,patients’ preoperative lower limb alignment should be carefully evaluated.