Vertebral body tethering for idiopathic scoliosis in children and young people

Evidence-based recommendations on vertebral body tethering for idiopathic scoliosis in children and young people. This involves fixing a cord to screws that have been placed into the vertebral bodies (bone discs in the spine), and pulling it taut to restrict growth on the long side of the spine.

# Recommendations
Evidence on the safety of vertebral body tethering for idiopathic scoliosis in children and young people is limited but raises concerns of serious complications. Evidence on its efficacy is inadequate in quality and quantity. Therefore, this procedure should only be used in the context of research. Find out what only in research means on the NICE interventional procedures guidance page.
Further research should include randomised controlled trials or analysis of registry data.
This procedure should only be done in specialist centres by spinal surgeons with specific training in anterior spinal surgery.# The condition, current treatments and procedure

# The condition
Scoliosis is a 3dimensional spinal deformity. It causes the bones of the spine to twist or rotate so that the spine curves sideways. Scoliosis curves most commonly happen in the upper and middle back (thoracic spine). It can also develop in the lower back and, occasionally, happens in both the upper and lower parts of the spine.
Idiopathic scoliosis is the most common type of scoliosis. It is a progressive condition, and its exact cause is unknown. There are 3 types of idiopathic scoliosis: infantile idiopathic scoliosis, juvenile idiopathic scoliosis and adolescent idiopathic scoliosis.

# Current treatments
Treatment of idiopathic scoliosis depends on a number of factors, including age, severity and location of the spinal curve, and the pattern and progression of the curve. In many cases, idiopathic scoliosis is mild and does not need treatment other than close monitoring and physical therapy. For moderate and severe scoliosis, treatment may progress through casting and bracing to spinal surgery.

# The procedure
Vertebral body tethering is a nonfusion spinal treatment for idiopathic scoliosis. The aim is to preserve the flexibility of the spine and modulate its growth on the concave and convex sides, so slowly correcting the scoliosis.
In this procedure, under general anaesthesia, screws are placed into each vertebra on the convex side of the spine. The screws are connected by a flexible cord. Tension is then applied to the cord to partially correct and tether the convex side of the spine and so restrict its growth. Thoracic tethers are usually done through a thoracoscopic or open approach and lumbar tethers need a miniopen approach. After surgery, the cord continues to restrict growth on the convex side while allowing faster growth on the concave side, so potentially producing further correction of the scoliosis.
The technique exploits a known reaction of bone to being stretched or being compressed. This response is known as the HeuterVolkmann law and notes that bone growth increases when stretched and decreases when compressed. In scoliosis this response can be used on a curved spine if the bones still have significant growth potential.