Temporary hemiepiphysiodesis for treatment of genu varum and valgum with pathologic physis in children / 中华骨科杂志

ABSTRACT

Objective To retrospectively analysis the clinical effect of temporary hemiepiphysiodesis for treatment of genu varus and valgus with pathologic physis in children.Methods All of 31 children (52 knees) were included in the study from January 2008 to December 2014,20 boys and 11 girls,the age at the time of surgery from 2 year 4 month to 13 year 4 month,mean 6 year 5 month.12 varus and 19 valgus,10 unilateral and 21 bilateral,41 femurs and 44 tibias.The Mechanichal Axis Deviation (MAD) was evaluated and the mechanical lateral distal femur angle (mLDFA) and medial proximal tibia angle (mMPTA) pre-operation and post-surgery was measured.Judging the efficacy with zone system for assessing mechanical axis based on Stevens,we think the results was satisfactory if the mechanical axis falls in zone ± 1 when removed the eightplate and other was unsatisfactory.We made statistical analysis of children who were corrected satisfactory and observed the change of the width and appearance of the physis.We also made the univariate analysis and Logistical multivariate regression analysis about sex,unilateral or bilateral,surgery age,femur or tibia,varus or valgus and severity of deformity to judge the influencing factors between satisfactory and unsatisfactory.We recorded the knee function and deformity recurrence at last follow up.Results The follow-up period was 2 year 6 month to 9 year 5 month,mean 4 year 1 month,44 knees (84.6％) were corrected satisfactory.The mean value of MAD at pre-surgery and at the time when the plate was removed were (-33.3t7.2) mm and (2.1 ±4.3) mm,mean mLDFA were 102.9°±4.9° and 85.3°±3.8°,mean mMPTA were 81.2°±3.4° and 90.5° ±4.4° in genu varus (21 knees);The meam value of MAD at pre-surgery and at the time when the plate was removed were 29.3±6.8 mm and-4.1±6.5 mm,and the mean mLDFA were 79.5o±5.7° and 88.1°±3.5°,mean mMPTA was 97.0°±4.3° and 87.1°±5.2° in genu valgus (23 knees),which were significant difference.There were 28 knees with physis width asymmetry in the 44 knees pre-operation and improved obviously after-surgery and the appearance became normally.8 knees corrected unsatisfactory included 2 varus and 6 valgus.The severity of deformity was a risk factor that affects efficacy with univariate analysis(t=5.124,P=0.000).Regarding the range of the age,we also did the logistic multivariate regression analysis with results showing that surgery age (OR=1.032) and se verity of deformity (OR=1.335) were related to the outcome.There were 8 knees in the 44 knees which had deformity recurrence and the rate was 19.5％ (8/41,3 knees excluded due to doing the limb lengthening surgery when removing the plate) at last follow up,and the knees function were normal.Conclusion Temporary hemiepiphysiodesis is a minimally invasive and effective method for treatment of genu varus or valgus with pathologic physis in children and could improve the appearance of the physis.The age at surgery and severity of deformity are the risk factors that affect efficacy.The pathological changes persisted could cause complication and deformity recurrence which need follow-up after removal of the plate.