Temporary Hemiepiphysiodesis Research Articles

Temporary hemiepiphyseal arrest using a screw and plate device to treat knee and ankle deformities in children: A preliminary report

Traditionally, angular deformities are treated by means of osteotomy. In patients who are skeletally immature, this major intervention can be avoided by influencing or guiding the growth of the affected physis. Recently, a new device was presented as an alternative to the widely used Blount staple. Stevens developed a technique using a two-hole, non-locking plate with two screws to perform temporary hemiepiphysiodesis in children. We studied the effectiveness of this new device in correcting angular deformities in children even younger than 5 years of age. We evaluated our first series of 11 patients (17 eight-Plates) who underwent treatment for angular deformities of various origins and were followed to completion of correction. The average age at hemiepiphysiodesis was 10 years and 2 months (age range 4 years and 11 months-13 years and 8 months). The device was inserted in the lateral distal femur (two cases), the medial distal femur (eight cases), the lateral proximal tibia (two cases), the medial proximal tibia (four cases), and the medial distal tibia (one case). The eight-Plate was inserted for an average of 9.5 months (range 5-13 months). The joint orientation angles and the mechanical axis improved in all patients, with the exception of one 13-year and 8-month-old boy with a resected osteosarcoma and a compromised growth plate. In valgus cases (12 limbs, 13 eight-Plates), the mechanical axis deviation improved by an average of 30.7 mm (range 13-55 mm). In varus cases (four limbs, four eight-Plates), the mechanical axis deviation improved by an average of 38.8 mm (range 0-74 mm). No hardware failures, extrusion, growth arrest, or other complications were observed. None of our patients required an osteotomy or repeat eight-Plate insertion. We consider the eight-Plate to be an ideal tool for treatment of angular deformities in growing children. It allows for precise insertion and is reliable. It is also less likely to extrude like the Blount staple.

Validation of a Genu Valgum Model in a Rabbit Hind Limb

Numerous techniques exist to correct pediatric angular deformity by asymmetrically inhibiting physeal growth. Despite decades of surgical experience, little is known about the determinants of success or failure of temporary hemiepiphysiodesis. We lack a basic understanding of tolerances and kinematics of the surgically restrained physis. Furthermore, little is known about the influence of implant design and placement on efficacy of deformity correction and rebound growth. We have undertaken a pilot research study with the goal of producing genu valgum in New Zealand white rabbits. This report comprises our initial experience and observations in performing hemiepiphysiodesis with staples and 2-hole plate techniques. The experimental hypotheses proposed by this article are as follows: (1) a staple or plate applied to the proximal lateral tibial physis of a rabbit hind limb will reliably create a valgus deformity of the knee; (2) the plate or staple will create this deformity without permanently damaging the proximal tibial physis; and (3) provided the implant remains in situ, there will be no difference between the plate and staple constructs with respect to the magnitude or rate of deformity produced. Further studies will aim to use this model to investigate technical issues related to physeal instrumentation.

Hemiepiphysiodesis for Posttraumatic Tibial Valgus

Posttraumatic tibial valgus is a recognized complication of proximal tibial metaphyseal fractures in children. There is no consensus regarding management of this malalignment; approaches range from repeated osteotomy to therapeutic nihilism. The authors present 12 patients with an average age at fracture of 4 years 11 months, each of whom who was successfully managed by temporary hemiepiphysiodesis. An additional patient (age 33 years) is included to illustrate the potential long-term outcome of "benign neglect."Using staples or, more recently, a 2-hole plate for guided growth, we have demonstrated correction of posttraumatic tibial valgus by all criteria; including mechanical axis deviation, lateral tibial metaphyseal-diaphyseal angle, tibiofemoral angle, and tibial length. We conclude that hemiepiphysiodesis is a safe and effective method of treatment with a high degree of patient/parent satisfaction. There have been no permanent growth arrests.