2 The technology

Description of the technology

2.1 The MAGEC spinal bracing and distraction system (Ellipse Technologies Inc.) is used in children aged 2 years or over to brace the spine during growth and minimise the progression of scoliosis. The technology is intended to be used in place of current growth rod systems that need repeated invasive surgical procedures. The MAGEC growth rods are usually removed and replaced by a spinal fixation system to fuse the spine when skeletal maturity is reached.

2.2 The MAGEC system comprises 1 or 2 sterile titanium implantable growth rods and an external remote control for non-invasive lengthening. The diameter of the rods used depends on the child's body weight (4.5 mm for children weighing up to 27 kg, 5.5 mm for children weighing up to 36 kg). The choice of whether to insert 1 or 2 rods is made by the surgeon and depends mainly on the child's size. A portion of each MAGEC rod contains a proprietary distraction element, the 'actuator', which includes an internal cylindrical rare earth magnet. The system also includes a manual distractor (to check the implant is functional before implantation) and a wand locator (to locate the internal magnet).

2.3 The MAGEC system received a CE mark in 2009 for the growth rods and external remote control. A keeper plate was added to the actuator in 2010 to prevent the internal magnet rotating. If this happened when the rod was placed under large amounts of stress, it could cause the rod to slip with some loss of distraction. Following the examination of rod breakages, the design was further revised in 2012 to strengthen the titanium rods by using continuous wave, rather than pulse, laser welding.

2.4 The MAGEC rods are inserted surgically in the same way as conventional growth rods. Distractions (lengthenings) are carried out typically every 3 months, depending on clinical assessment and the surgeon's judgement as to the optimal length of time between distractions for the individual child. The distractions are performed in an outpatient setting without the need for anaesthesia, sedation or pain relief. The magnet within the actuator is connected to a lead screw and is rotated non-invasively by the external remote control, causing the rod to lengthen and increase the distraction of the spine. The external remote control is portable and uses permanent magnets to rotate the magnet within the rod. The control's display module gives a real-time indication of the amount of distraction or retraction gained. Verification of the new rod length can be done using X-ray or ultrasound if needed.

2.5 The cost of the MAGEC system stated in the sponsor's submission is £13,500 to £14,000 for a set of dual rods, with an additional £450 to £500 for the hooks and screws (supplied by another company) to attach the rods to the spine. These costs are exclusive of VAT. The external remote control is loaned by the sponsor at no cost, other than that of sending it to the treatment centre.

2.6 The claimed benefits of the MAGEC system in the case for adoption presented by the sponsor are:

  • The avoidance of repeated surgical procedures, leading to:

    • A reduction in the incidence of surgical complications, including anaesthetic risk, infections and delayed recovery.

    • A reduction in psychological trauma to the child and family.

    • Improved quality of life because of reduced time away from school (child) and work (parent).

  • The avoidance of costs associated with repeated surgical interventions, including theatre time, consumables, in-hospital stay and treatment of complications.

  • A reduction in costs to society associated with the parent or carer taking time off work and the child being away from school.

Current management

2.7 In many cases of childhood scoliosis, interventional treatment is not needed because the condition corrects itself as the child grows. For those children needing treatment, there are 4 main types, namely casting, bracing, insertion of growth rods and spinal fusion. The type of treatment chosen depends on the age and development of the child as well as the type of curvature of the spine. Casting involves use of an external cast, made from a combination of plaster-of-Paris and modern casting material, which is applied to help guide a child's spine into a normal position during growth. The cast is worn permanently by the child and is replaced frequently as the child grows. Bracing involves use of a rigid or flexible brace. Bracing rarely corrects scoliosis, but can prevent curve progression and allow the spine to grow before a more permanent treatment is offered.

2.8 Around 120 children with scoliosis per year in England need surgical intervention to implant growth rods to correct the curvature of their spine. This type of surgery is performed if the spinal curvature progresses despite bracing and casting. It involves inserting growth rods (single or dual), which are attached to the spine or ribs above and below the curve using hooks and pedicle screws. The rods can be placed around the cervical or thoracic part of the spine, extending down to the ribs, lumbar spine or pelvis. The initial insertion procedure for the MAGEC system is similar to that for conventional growth rods and usually involves staying in hospital for 5–14 days and several weeks away from school and usual daily activities. If a conventional growth rod is used, the child returns about every 6 months to have a surgical procedure for rod lengthening. The procedure involves manually lengthening the growth rods via small incisions in the back under general anaesthesia. This can be done as a day case procedure but may often involve an overnight stay in hospital.

  • National Institute for Health and Care Excellence (NICE)