Hemiepiphysiodesis using tension band plates: Does the initial screw angle influence the rate of correction?

Abstract

Purpose When using tension band plates for angular deformity correction, the literature is unclear regarding the most effective screw insertion angle to use. This study evaluates the correlation between initial screw angle and the average rate of correction during hemiepiphysiodesis using tension band plates Methods This retrospective study includes 35 patients (47 physes) with genu valgum deformity (17 idiopathic and 18 fibular hemimelia) who underwent insertion of Eight-Plates between 2010 and 2015. Initial screw angle was determined from the intraoperative fluoroscopic images. Radiographs were obtained within three months of surgery, and follow-up films were obtained every three to six months. Change in mechanical lateral distal femoral angle, medial proximal tibial angle and screw angle was obtained from each follow-up radiograph. Initial screw angle was correlated with the average rate of correction during the entire treatment period. The average rate of angular correction during first and last follow-up periods was also compared. Results The relationship between the initial screw angle and the mean rate of angular correction was not statistically significant (p = 0.2). The rate of angular correction during the first follow-up period (mean of 4.7 months) was 0.86° per month compared with 0.71° per month during the last follow-up period (mean of 5.1 months). Conclusion Application of a tension band plate with a divergence angle ranging from 0° to 30° results in similar rates of angular correction. For surgeons inserting screw-plate tension band devices, there does not seem to be any necessity to make the screws parallel or divergent. We recommend that screw placement be anatomically correct, i.e. not impinging on the physis, rather than favouring any particular divergence angle. Level of evidence IV

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

“…The initial SDA was not related to the correction velocity in the present research. This result was consistent with Eltayeby HH et al’s [ 21 ] research. Our study did not find a significant relationship between the percentage of screw length accounting for femoral or tibial physis width and the correction velocity.…”

“…In the present study, 94% (95/101 knees) of the genu angular deformities were completely corrected, and the mean deformity correction period was approximately 13 months. Non-idiopathic genu angular deformity was 12.71 ± 1.98 (12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24) Values are presented as the mean ± SD (range) or frequency (percentage) a calculated according to the number of limbs found to be an independent risk factor for deformity correction failure and complications. The femoral correction velocity was significantly faster than the tibial correction velocity.…”

Growth modulation with tension-band plates for the correction of paediatric lower limb angular deformity: current concepts and indications for a rational use

“…Stevens recommends divergent screws at the outset to reduce the lag time for correction. 27 Eltayeby et al 28 showed that divergence angle ranging from 0° to 30° results in similar rates of angular correction, and their final recommendation was that adequate screw placement should be the priority rather than favouring any particular divergence angle.…”

Comparison of histomorphometric and radiographic effects of growth guidance with tension-band devices (eight-Plate and FlexTack) in a pig model

“…Eltayeby et al. ( 2019 ), on the other hand, did not detect a significant correlation between the initial screw angle and the average rate of correction; they stated that a wider initial screw angle did not result in a faster correction rate. Vogt et al.…”