Pediatric Scoliosis Surgical Technologies: Growing Rods, Growth-Guided Devices, Vertebral Body Tethering

Before and after surgery x-rays demonstrate the effectiveness of these technologies in select patients

This article is a continuation of the Pediatric Scoliosis Surgery Guide that explains spinal fusion, in-situ fusion, spinal fusion with instrumentation, and hemivertebra removal.

Traditional Growing Rods for Pediatric Scoliosis
Children younger than age 8 have years of growth ahead, including their thorax (chest) that supports development of the lungs. In these children, growth-sparing procedures are desirable. Spine- or rib-based growing rod systems, such as the vertical expandable prosthetic titanium rib device (VEPTR®), use instrumentation to attach one or two rods to the spine (with screws, hooks, and screws) or ribs (with special hooks and brackets) above and below a spinal curve.

After the initial surgery, your child may wear a special brace. Follow-up outpatient visits with the surgeon are necessary to lengthen the rods to facilitate your child's growth.

When your child’s spine has reached its maximum length, and their chest is matured, your surgeon removes the temporary rods and screws, hooks and/or brackets and performs spinal fusion to straighten the scoliosis and stabilize the spine.

The VEPTR device, a relatively new device introduced over the past twenty years is the first FDA-approved treatment for thoracic insufficiency syndrome, which some young children develop as a result of their scoliosis causing them difficulty to breath.

X-rays of VEPTR, the vertical expandable prosthetic titanium rib deviceMagnetically Controlled Growing Rods for Pediatric Scoliosis
The difference between a traditional growing rod system and a magnetically controlled growing rod (MCGR) surgery is MCGR allows rod lengthening without general anesthesia and a surgical incision. Rather, MCGR allows your child to stay awake during rod lengthening while external magnets adjust the rods.

Each MCGR rod contains a small magnet. An external remote control device triggers the magnet to change the size of the rods while the child is awake in the surgeon's office.

post-operative standing x-ray shows magnetically controlled growing rods for treatment of pediatric scoliosisThere are a host of benefits to MCGR, including:

  • No follow-up surgeries are required after the initial implantation surgery
  • No need for anesthesia
  • Reduced costs
  • Reduced stress and anxiety for children and parents

Growth-Guided Devices for Pediatric Scoliosis
Growth-guided devices use instrumentation designed to correct the scoliosis while allowing the child to grow. Like a growth rod approach, two rods are implanted on each side of the spine. With growth-guided devices, the rods are attached to screws or wires, called anchor points, along the spine. The difference between growth-guided devices and traditional growing rods or MCGR is the spine is left to grow on its own after the initial procedure. As the child grows, the spine elongates along the rod.

The initial surgery is performed to implant the rods and anchor points. Unless a problem with the implant occurs, which can happen with any of the growth-sparing procedures, the final surgical procedure involves removing the device.

Two common growth-guided devices are the Luque trolley and Shilla technique.

  • The Luque trolley uses wires to facilitate spine growth as the wires slide along contoured rods. This is seldom used by surgeons today.
  • With the Shilla procedure, the surgeon first performs a spinal fusion at the most severe portion of the scoliotic curve; termed the apex. The surgeon then places anchor points at the top and bottom of the curve. These points will guide the rods to allow the spine to grow longer. The screws at the ends of the spine are specially designed to allow movement and growth along the rod which is not statically fixed to the spine.
  • All the growth-sparing procedures described above have the potential for breakage of the rods that may require additional surgery. Your child’s surgeon will describe the benefits of the operations as well as the potential problems that can occur along the way that may require surgical intervention.

The patient below underwent the Shilla procedure. Images were taken from the patient’s initial pre-op visit, post-op visit and then another post-op visit after the patient’s second surgery.

post-operative standing x-rays show use growth-guided Shilla procedure in treatment of pediatric scoliosisVertebral Body Tethering: Fusionless Pediatric Scoliosis Correction
Vertebral body tethering (VBT) is fusionless surgery and is appropriate for some children with progressive scoliosis. VBT involves a surgical procedure where titanium screws are implanted into the vertebral bodies on the convex side (outward section) of the scoliotic curve. The screws are coated with a substance that stimulates each implanted screw to fuse with the vertebral bone. A flexible, strong cord designed for fusion is secured to each screw and sequentially tightened to help straighten the abnormal curve.

The surgical team includes the spine surgeon, an assistant surgeon, and a thoracic surgeon. Under general anesthesia, small incisions are made at the side of the child’s chest—it is a type of thoracic surgery called video-assisted thoracoscopic surgery (VATS). Through a small scope, a video camera is inserted into the surgical field allowing the surgeon to see the patient’s anatomy and precisely guide his instruments throughout the VBT procedure.

After the surgical procedure, VBT continues to correct the scoliosis through growth modulation—that means the tethered side of the spine grows less that the side that is not tethered.

The VBT approach is currently being studied under FDA jurisdiction, and the long-term benefits of VBT remain to be studied. FDA approval of the implants for this indication have not yet been received.

Potential advantages of VBT include:

  • The procedure is less invasive
  • Spinal growth and flexibility are preserved
  • Correction of the curve occurs during growth
  • Patients are more comfortable, able to move more freely
  • VBT does not obviate other scoliosis surgery if needed

post-operative standing x-rays show vertebral body tethering in treatment of pediatric scoliosisLife After Pediatric Scoliosis Surgery
Regardless of the pediatric scoliosis surgery your child undergoes, your surgeon will develop a postoperative plan to maximize the effectiveness of the treatment. Your child will have regular follow-up visits so your doctor can monitor the curve. And, in most cases, physical therapy and exercise will be recommended. With your support during the recovery period, your child will have a healthy spine and happy future.

Updated on: 05/09/17
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Pediatric Scoliosis Surgery Guide

Pediatric Scoliosis Surgery Guide provides information about curve correction in young patients, including spinal and in-situ fusion, instrumentation, and hemivertebra removal.
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