Removing Only the Metaphyseal Screw after Completion of Deformity Correction with 8-plate Hemiepiphysiodesis. Is it Wise and Safe?

Purpose: Guided growth using plate and screws became the gold standard for correction of angular deformities in children and adolescents. Recurrence of the deformity is a well-known phenomenon in skeletally immature patients, therefore It has become a routine strategy to remove the metaphyseal screw from the plate construct after desired correction was achieved, theoretically allowing easy reinsertion in case of deformity recurrence. The purpose of the current study was to evaluate efficacy and safety of this procedure.

Methods: We reviewed the results of 93 patients (132 limbs) that were treated by guided growth using an 8-plate and screws around the knee. We documented the number of cases that upon deformity correction the 8–plate construct was only partially removed (metaphyseal screw only), and the number of cases with deformity recurrence that required reinsertion of the metaphyseal screw.

Results: The mean age at the time of initial surgery was 8.9 years .In 55 limbs the metaphyseal screw was removed after achieving desired correction. We found that 12 limbs from this group (22%) showed radiographic signs of recurrence and underwent reinsertion of the metaphyseal screw. The mean time from screw removal to reinsertion was 14.6 months (range 7-22 months). In 7 out of 12 patients (58%) we had to relocate or exchange the plate because metaphyseal hole was unsuitable for screw reinsertion. Two patients developed a bony bar with partial growth arrest and required additional surgery.

Conclusions: Based on our experience leaving the plate with an epiphyseal screw is not safe and not advisable. The majority of plates were unsuitable for screw reinsertion and two patients developed partial growth arrest, therefore exposing patients to unnecessary risk.