Temporary hemiepiphysiodesis using an eight‐plate implant for coronal angular deformity around the knee in children aged less than 10 years: efficacy, complications, occurrence of rebound and risk factors

Abstract

Background Temporary hemiepiphysiodesis (TH) using an eight-Plate implant is one of the most common surgeries used for the correction of coronal angular deformities around the knee in adolescents. However, few studies have focused on children aged less than 10 years treated with TH using an eight-Plate implant. The purpose of this study was to investigate the efficacy, correction velocity, and complications of TH with an eight-Plate implant as well as the occurrence of rebound and risk factors in this population. Methods This retrospective study included a total of 135 physes (101 knees) from 66 children (mean age of 4.69 years old, range from 1 to 10 years old) who underwent TH with an eight-Plate implant to correct coronal genu angular deformities in our hospital. Related clinical factors were recorded and analysed by multivariable linear and logistic regression models. Results The mean deformity correction period was 13.26 months, and the mean follow-up after eight-Plate removal was 12.71 months. In all, 94.06% (95/101 knees) of the genu angular deformities were completely corrected. Non-idiopathic genu angular deformity was found to be an independent risk factor for deformity correction failure (odds ratio (OR) = 2.47). The femoral correction velocity was significantly higher than the tibial correction velocity (1.28° vs. 0.83° per month, p < 0.001). After adjustment for other factors, younger children had higher correction velocities in the distal femur; however, genu valgum and idiopathic deformities were associated with higher correction velocities in the proximal tibia. In addition, we found three (3/101, 2.97%) knees with genu valgum that experienced rebound after removal of the eight-Plate, while five (5/101, 4.95%) knees with non-idiopathic genu angular deformity experienced screw loosening. No other complications were found, and non-idiopathic deformity was the only risk factor for complications (OR = 3.96). No risk factor was found for rebound in our study. Conclusions TH using an eight-Plate implant is an effective procedure for coronal genu angular deformities with a low incidence of complications and rebound in patients younger than 10 years old. For this population, TH using an eight-Plate should be considered as soon as the deformity stops responding to conservative treatments. The parents of children younger than 10 years of age with non-idiopathic deformities should be informed preoperatively that the deformity may be prone to correction failure or screw loosening after eight-Plate implantation.

Factors Affecting Rebound Phenomenon After Temporary Hemiepiphysiodesis and Implant Removal for Idiopathic Genu Valgum in Adolescent Patients

“…In fact, many previous studies on temporary hemiepiphysiodesis have reported its varying frequencies and degrees. 4,[7][8][9] As exactly predicting the timing of skeletal maturity is difficult in growing patients, understanding postoperative courses after temporary hemiepiphysiodesis and implant removal is essential for optimal results. However, studies dealing with postoperative courses after implant removal are still rare.…”

Risk Factors for Rebound After Correction of Genu Valgum in Skeletal Dysplasia Patients Treated by Tension Band Plates

“…This is consistent with literature showing that younger children with both idiopathic and nonidiopathic genu valgum developed rebound after TBP removal. 7,8 Ramazanov et al 15 reported similar age group results. Also, they had more rebound in cases with femur physes treated by TBP than tibia (femur 60% and tibia 50%).…”

“…The published literature is not specific regarding selection of cases for overcorrection. 7,8,15,18 In addition, Leveille et al 9 suggested that surgeons' consider the etiology of lower limb deformity before performing overcorrection; however, they did not give definitive guidelines. From our data, we cannot propose reliable calculations for the prediction of overcorrection versus rebound.…”

“…A reported complication of TBP in idiopathic genu valgum is a rebound deformity, and data concerning this complication in children with SKD are scant (mixed diagnoses are often termed as "nonidiopathic"). [7][8][9]11,15 In our study, we included all cases of SKD that met the inclusion criteria, and we derived 3 conclusions. First, growth modulation surgery utilizing a TBP technique corrected the genu valgum deformity in all of our patients.…”

“…Many publications show successful correction of lower extremity angular deformities by TBP surgery, which include a mixed group of conditions such as SKD, metabolic disorders, congenital dysplasias, and amputees, with TBP in children with idiopathic or nonidiopathic conditions. [6][7][8][9][10][11] An important complication of TBP surgery is rebound deformity (growth-related recurrent angular deformity after TBP removal) 6 ; however, there is scant literature concerning rebound deformity in children with only SKD treated with TBP surgery. The phenomena of the "rebound" presents problematic situations for the patient and surgeon.…”