Affecting Factors and Correction Ratio in Genu Valgum or Varum Treated with Percutaneous Epiphysiodesis Using Transphyseal Screws

Abstract

This study evaluated the correction rates of idiopathic genu valgum or varum after percutaneous epiphysiodesis using transphyseal screws (PETS) and analyzed the affecting factors. A total of 35 children without underlying diseases were enrolled containing 64 physes (44 distal femoral (DT), 20 proximal tibial (PT)). Anatomic tibiofemoral angle (aTFA) and the mechanical axis deviation (MAD) were taken from teleroentgenograms before PETS surgery and screw removal. The correction rates of the valgus and varus deformities for patients treated with PETS were 1.146°/month and 0.639°/month using aTFA while using MAD showed rates of 4.884%/month and 3.094%/month. After aTFA (p < 0.001) and MAD (p < 0.001) analyses, the correction rate of DF was significantly faster than that of PT. Under multivariable analysis, the aTFA correction rate was significantly faster in younger patients (p < 0.001), in males (p < 0.001), in patients with lower weights (p < 0.001), and in the group that was screwed at DF (p < 0.001). Meanwhile, the MAD correction rate was significantly faster in patients with lower heights (p = 0.003). PETS is an effective treatment method for valgus and varus deformities in growing children and clinical characters should be considered to estimate the correction rate.

Factors Affecting Postoperative Courses After Removal of Transphyseal Screws Inserted for Correction of Genu Valgum

“…This is the originality of this study, which is different from previous studies on hemi-PETS. [6][7][8]11,12,17 Similar to our results of growth inhibition at the distal femur, Park et al 12 reported the overcorrection of the distal femur after hemi-PETS and screw removal, while the proximal tibia was stable. Different from their study, 12 we included surgery-related factors and concluded that an excessive peripheral position of a screw might be associated with excessive correction.…”

“…However, studies dealing with factors affecting postoperative courses after the removal of transphyseal screws are still rare and limited. 7,11,12 With this background, we conducted a study on hemi-PETS performed in adolescent patients with idiopathic genu valgum at our institution. The aim of our study was to investigate factors determining the final outcomes of hemi-PETS, especially focusing on postoperative courses after screw removal.…”

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

“…It has recently been advocated by many surgeons, because it is a minimally invasive procedure compared with other methods that need a wider exposure. 8,10,15,17 However, physeal damage is one of concerns when performing PETS because it directly involves the physes. In our study, the mean rebound angle in the SG was 1.1 ± 3.1 degrees, and it was significantly lesser than that in the PG.…”

“…The principle finding of this study was that the use of tension-band plates and faster correction speed were associated with the rebound phenomenon after temporary hemiepiphysiodesis for idiopathic genu valgum in adolescent patients. Different from previous studies on temporary hemiepiphysiodesis for genu valgum, 3,4,[6][7][8][9][10]15 we analyzed various parameters including the type of implant based on the regression analyses to suggest significant factors of the rebound phenomenon. By referencing our results of the linear regression model (model 2 in Table 4), the use of tension-band plates (compared with transphyseal screws) averagely resulted in an increase of 1.7 degrees rebound angle, and an increase of 1 degrees/month correction speed averagely resulted in an increase of 1.7 degrees rebound angle.…”

“…Percutaneous epiphysiodesis using transphyseal screws (PETS), introduced by Metaizeau et al,16 is a popular method of temporary physeal suppression. It has recently been advocated by many surgeons, because it is a minimally invasive procedure compared with other methods that need a wider exposure 8,10,15,17. However, physeal damage is one of concerns when performing PETS because it directly involves the physes.…”