UK-based Stanmore Implants received FDA approval for its Juvenile Tumour System (“JTS”) non-invasive extendible distal femoral replacement. Indicated for use in pediatric ortho oncology surgeries, the implant can later be slowly extended using an external magnet system without having to perform another invasive procedure on the patient.
At its core, the JTS implant is lengthened by a small yet powerful gearbox, which drives the extension. Remarkably, the gearbox is able to output ample force to lengthen the limb via a speed reduction ratio of 13061:1. With the implant in place, the limb is periodically lengthened by placing the limb into the external drive unit.
By passing electric current into an electric coil, the drive unit produces a rotating magnetic field at 3000rpm. This rotation is captured by the magnet within the implant and is passed through the gearbox to extend the implant. The implant will grow at 1mm every 4 minutes, thereby slowly stretching the soft tissues.