Purpose— to evaluate the impact of frontal positioning of prosthesis components after bilateral Tka on short term functional outcomes. Material and Methods. The authors performed a retrospective analysis of teleroentgenograms of 466 patients after bilateral Tka with initial varus deformity. Functional and roentgenological outcomes were evaluated at average in 16,4±2,9 months postoperatively. Mean preoperative varus deformity was 10° (from 5 to 25°), initial angle between the anatomical and mechanical femoral axis (FVa) was 6,7±2° (from 3 to 12°). The neutral axis of both lower limbs (Hka = 180±0,5°) was obtained in 99 (21,2%) out of 466 patients. Residual deformity in one of the limbs above 3° with the neutral alignment of the contralateral limb was observed in 44 (9,4%) patients, bilateral residual deformity – in 32 (6,9%) patients. Other 291 patients demonstrated the deviation from mechanical axis in the range from 1 to 3° (±0,5°). all patients were divided into three groups: first group consisted of 10 patients with neutral axis of one limb and varus deformity of the other limb above 3°; second group — 10 patients with bilateral residual varus deformity above 3°; third group — 12 patients with neutral axis of both limbs (Hka = 180°). The angle of residual deformity averaged 3,7° (from 3,2 to 5,1°).Results.No statistically significant differences between the groups were observed for dynamometric parameters and SF-36 scores, as well as for functional kSS scores (p>0,05). However, the authors reported in patients of the first group a stance phase on the side of residual varus deformity longer at 15% (p<0,05) and transfer phase shorter at 17% (p<0,05) as compared to contralateral limb (with neutral alignment, Hka = 180°), which is indicative of load asymmetry and can have a negative impact at a later stage.Conclusion. Symmetrical residual varus deformity of lower limbs in the rage of 3,2–5,1° has no negative impact of short term clinical and functional outcomes of Tka. Muscular function and gait properties in patients with neutral axis of the lower limbs and in patients with symmetrical residual varus deformity after Tka were similar 16,4±2,9 months postoperatively.

Цель исследования-оценить влияние остаточной варусной деформации нижней конечности после тотального эндопротезирования коленного сустава (ТЭКС) на клинико-функциональные и динамометрические результаты лечения. Материал и методы. В период с сентября 2014 по май 2015 г. была выполнена 951 операция тотального эндопротезирования коленного сустава 933 пациентам с исходной варусной деформацией нижней конечности. Однако в 52 (5,5%) случаях сохранилась остаточная варусная деформация более 3°. Группы исследования были сформированы с применением критериев включения и исключения. В основную группу вошли 36 пациентов со средней остаточной варусной деформацией нижней конечности 3,9±0,74° (от 3,1 до 5,6°), в контрольную-34 пациента с нейтральной механической осью нижней конечности. Оценка результатов лечения проводилась в среднем через 14,2±1,8 месяцев после операции с помощью функциональных шкал kSS (knee Society Score), субъективной оценки качества жизни (SF-36), а также оценка статико-динамической функции нижней конечности на лечебнодиагностическом комплексе Biodex Systems 4 Quick Set и оценка стабильности фиксации компонентов по шкале F.C. Ewald в модификации О.А. Кудинова с соавторами. Результаты. Функциональная оценка результатов по kSS (knee Society Score) в основной группе пациентов составила 84,0±4,6 баллов, в контрольной-82,2±4,1 (p˃0,05). Субъективная оценка качества жизни по шкале SF-36 в основной группе составила 162,6±6,4 баллов, в контрольной-164,3±8,1 (p˃0,05). Оценка статико-динамической функции нижней конечности на лечебно-диагностическом комплексе Biodex Systems 4 Quick Set в среднем через 14,2±1,8 месяцев после тотального эндопротезирования коленного сустава существенной разницы в обеих группах не выявили: как изометрические, так изокинетические параметры в обеих группах не имели статически достоверных различий (p˃0,05). Статистически достоверных различий между группами по шкалам kSS и SF-36, результатам динамометрии и рентгенологическим признакам стабильности фиксации компонентов эндопротеза выявлено не было (p˃0,05). Заключение. Наличие остаточной варусной деформации в коленном суставе после ТЭКС у пациентов с исходной варусной деформацией нижней конечности не повлияло на клинико-функциональные, рентгенологические и динамометрические результаты через 14,2±1,8 месяцев после операции. Ключевые слова: тотальное эндопротезирование коленного сустава, механическая ось нижней конечности, варусная деформация, динамометрия.

The importance of measuring of the angle between the mechanical and anatomical femoral axis (fVa) during the preoperative total knee arthroplasty (TKa) planning is not recognized by all. Some surgeons believe that it is acceptable to set distal femoral resection guide at 6° or 7° in all cases or adjust femoral resection guide fVa accordingly with patient height. We conducted two studies. one-retrospective analysis of radiographs of patients with TKa performed since 1.09.2014 till 31.01.2015 (n = 261, 273 TKa). In this cohort, we were looking for correlation between the parameters obtained on long hip-knee-ankle radiographs (fVa, coronal knee alignment) and gender, age, body mass index (BMI) and height, as well as the implant model and the level of constraint. after that we conducted a prospective, randomized trial with TKa performed since 1.02.2015 till 31.05.2015 (n = 225, 225 TKa). The patients were randomly divided into two groups. In the "individual fVa" group (n = 121), the distal femoral resection guide fVa was set accordingly with measured fVa, in the control group (n = 104)-at 7° (average fVa for the Sverdlovsk area patients' population). We compared TKa x-ray results of both groups. Results. first stage. We found no correlation between fVa and age, BMI, height and sex of patients (p>0.05). after TKa residual varus deformity of more than 3° (malalignment) (3.9±1.06) was observed in 7% of cases (19 joints). We found correlation between coronal knee malalignment after TKa and two factors: BMI and initial severity of varus deformity (p = 0.003 and p<0.001). Second stage. In the control group we've seen femoral component deviation of more than 3° from the perpendicular to neutral mechanical axis (malposition) 3 times more often then in the "individual fVa" group (9 vs. 3, p = 0.021). Conclusions. We did not identify the dependence of fVa on sex, age, BMI and height. With initial varus of more than 20° and BMI of more than 30 kg/m 2 , the risk of coronal components malalignment is increased. The average fVa in patients of Sverdlovsk area is 6,7±1,5° (3-11°). Implementation of preoperative fVa measurement and following femoral distal cut adjustments improves femoral component positioning and overall leg alignment postoperatively.