Clinical Application Of Medial Knee Soft Tissue Release Combined With Secondary Osteotomy In TKA Of Flexion Varus Knee

Objective:In flexion varus knee TKA,individualized medial soft tissue release technique combined with secondary osteotomy was used to balance the knee joint,and the surgical effect was evaluated.The characteristics of soft tissue balance of knee joint with flexion deformity in TKA were analyzed as clinical reference.Method:The patients with knee varus with flexion deformity who were admitted to the Department of Bone,Joint and Sports Medicine,China-Japan Friendship Hospital of Jilin University from January 2019 to January2021 were retrospectively analyzed.45 patients who met the criteria were included.The genu varus was classified according to the improved version of Krackow.The degree of flexion after anesthesia was mild <10 °,moderate 10 °-30 °,severe > 30 °.According to the release order of medial soft tissue of knee during operation,the patients were divided into mild release,moderate release and extensive release.Look up the medical records in the hospital information system and collect the data before and after operation.Including the patient’s age,sex,BMI,previous history,preoperative KSS score,varus angle,number of residual flexion contracture after anesthesia,intraoperative records: degree of release of medial knee soft tissue,osteotomy,number of residual varus,number of residual flexion,certificate of implant equipment,relevant imaging data before and after operation,postoperative complications,follow-up X-ray of knee joint,KSS score and ROM.To compare the efficacy of medial knee soft tissue release combined with secondary osteotomy after TKA,and to analyze the soft tissue balance strategy needed in TKA in patients with partial varus and flexion deformity.Results:Forty-five patients included in the study were followed up for 1 year,and the follow-up data were partially missing 3 months after operation.There were 16 males and 29 females,the age was 69.16 ±7.50 years old,BMI26.03 ± 2.30 Kg/m2.The causes included KOA25,17 cases of rheumatoid arthritis,1 case of gouty arthritis,1 case of psoriasis with OA1 and 1 case of tuberculous arthritis.After operation,there were 1case of deep venous thrombosis of lower extremities,2 cases of poor incision healing,and no other complications.The clinical score of KSS increased gradually from 45.76 ±11.16 before operation to 88.20 ±2.08 at the last follow-up.The preoperative KSS function score increased from 40.93 ±10.98 to 85.11 ±2.08.The range of motion（ROM）of knee joint was improved from 90 °（85 minutes96）° before operation to 112（109116）°.There were significant differences in KSS score and ROM at each time point.However,there was no significant difference in KSS score and ROM at 6 months and 12 months after operation.The more serious the knee varus flexion deformity is,the longer the operation time is,and the medical burden is increased.There is a correlation between the degree of flexion and the degree of varus,but it is non-linear.The degree of residual flexion after anesthesia was 14（12 ～ 16）°,which was more than moderate flexion contracture deformity.There were 5 cases of Krackow I conventional release,11 cases of mild release and 1 case of moderate release.The soft tissue release was mainly mild release,accounting for 40%.Krackow Ⅱ moderate release in 15 cases,extensive release in 4 cases,mainly moderate release,accounting for 76.9%.There were 9 cases of Krackow type Ⅲ,mainly with extensive release.There were significant differences in KSS scores of different types before and 1.5 months after operation.However,there was no significant difference in KSS score between Krackow type Ⅰ and type Ⅱ at 6 and 12 months after operation.Conclusions:1.Individualized medial knee soft tissue lysis combined with secondary osteotomy had a good early follow-up effect after TKA of flexion varus knee,and reached the best rehabilitation state 6 months after operation.2.Appropriate secondary osteotomy is needed when the residual flexion deformity after anesthesia is more than moderate,and there is a correlation between the degree of flexion and the degree of varus,but non-linear correlation.3.Most of Krackow type Ⅰ and type Ⅱ did not exceed moderate release,and the healing effects of Krackow type Ⅰ and type Ⅱ were close to each other after individual release and osteotomy.Krackow type III is more likely to face the complex soft tissue balance during TKA,so a variety of surgical plans should be made.