eightplate

Eightplate, also known as an eight-plate or tension-band plate, is a small, low-profile orthopedic implant used in pediatric guided growth. It consists of a figure-eight shaped plate with two screws that cross the growth plate (physis) to create a dynamic tension band across the physis.

Mechanism and purpose: The plate is applied across a physis on the convex side of a angular deformity. By slowing growth on that side while allowing the opposite side to continue growing, the alignment gradually shifts toward normal as the child grows. The construct is designed to be temporary and reversible, enabling gradual correction without permanently arresting the physis.

Indications and sites: Eightplates are commonly used to treat angular deformities around the knee in children with open physes, such as genu valgum (knock-knee) and genu varum (bowlegs). They may also be used in other growth-plate–related deformities when guided growth is appropriate. The choice of site depends on the deformity and remaining growth potential.

Procedure and follow-up: The procedure is minimally invasive. Under anesthesia, two screws are placed across the physis on the convex side, and the plate bridges the physis to act as a tension band. Patients typically begin with unrestricted weight bearing as advised by the surgeon. Serial radiographs every 3–6 months monitor progress. The duration of treatment varies, with correction often achieved over several months to a year.

Advantages and risks: Benefits include reversibility, preservation of growth potential, and gradual correction with a less invasive approach compared with irreversible procedures. Potential risks include screw loosening or migration, plate failure, over- or under-correction, physeal injury, and the need for hardware removal after correction or at skeletal maturity.

See also: guided growth, hemiepiphysiodesis, tension-band plating.