Anterior Release for Kyphosis

A severe, long-standing kyphosis can become very stiff, with the front of the spine effectively locked by a tight anterior longitudinal ligament and stiff, wedged discs. When a curve is that rigid, correcting it purely from the back can be difficult, because the spine will not bend enough. The rationale for an anterior release is to unlock the front of the spine first — dividing the tight ligament and removing the discs at the apex — so that the curve becomes mobile and can then be straightened during the posterior fusion. It is essentially a flexibility-creating step rather than a correction in itself. It is considered mainly for the stiffest and most severe curves. It is important to note that, with modern pedicle-screw constructs and posterior osteotomies, most kyphosis can now be corrected from the back alone, so anterior release is used far less than it once was and is reserved for particular rigid deformities.

This is what is generally done, although techniques vary between surgeons and centres. Access is gained to the front of the spine at the apex of the curve. Traditionally this was through an open incision in the chest (a thoracotomy), but it is now often performed using keyhole techniques — video-assisted thoracoscopic surgery — in which small incisions and a camera are used to reach the spine through the chest. Once the front of the spine is reached, the anterior longitudinal ligament is divided and several discs at the apex are removed (on average around five levels), which releases the tether and lets the spine become flexible. Bone graft may be placed in the emptied disc spaces to encourage fusion. In practice the release is almost always followed — either in the same sitting or shortly afterwards — by a posterior instrumented fusion, which is what actually corrects and holds the curve. The lungs are protected and monitored because the operation is within the chest.

The literature shows that anterior release genuinely increases the flexibility of a stiff spine — measured flexibility of the curve improves substantially after release — which is its purpose. Studies comparing keyhole thoracoscopic release with the older open thoracotomy find that the two achieve comparable correction when combined with posterior fusion, but that the keyhole approach causes less damage to the chest wall, although it carries a significant surgical and anaesthetic learning curve and an overall complication rate that is not trivial, dominated by breathing-related events. Open thoracotomy causes a temporary dip in lung function that generally recovers over about two years. The most important theme in the recent literature, however, is that the need for anterior release has declined markedly: because strong posterior pedicle-screw systems and osteotomies now allow most kyphoses to be corrected from the back alone, several major centres report that anterior release is rarely required today and is reserved for the most rigid curves.

Because an anterior release is usually one part of a two-part treatment, recovery is considered together with the posterior correction that accompanies it. Where the chest has been entered, a temporary drain is commonly used for a short time and breathing is supported and monitored closely, since the operation is within the chest. Getting up and moving is encouraged as soon as it is safe. If the posterior fusion is done at the same time or shortly after, the overall recovery follows that of a spinal fusion — a hospital stay of several days, a gradual return to activity over months while the fusion becomes solid, and long-term follow-up of the spine. Families and patients should understand that the release itself does not straighten the spine; it prepares a stiff spine so that the correction can be achieved.

Reaching the front of the spine through the chest carries its own risks, which the team explains fully beforehand — including bleeding, infection, effects on the lungs and breathing (a temporary reduction in lung function is common), and the risks of chest surgery generally. Keyhole techniques reduce chest-wall injury but require particular expertise. Because anterior release adds an operation, and its main modern alternative — posterior-only correction — now achieves similar results in most cases, the decision to include a release is made carefully and reserved for curves that genuinely need it. This page is educational and does not recommend or advise for or against surgery, or any particular approach, in any individual case.

• —Newton PO et al. Anterior release and fusion in pediatric spinal deformity: thoracoscopic vs open thoracotomy — early outcome and cost. (PMID 9201845)
• —Anterior thoracoscopic spine release in deformity surgery: a meta-analysis and review. (PMID 10766053 / PMC3611438)
• —Treatment of stiff thoracic scoliosis by thoracoscopic anterior release combined with posterior instrumentation and fusion. (PMID 17937803 / PMC2173894)
• —The 15-year evolution of the thoracoscopic anterior release: does it still have a role? (PMID 26240714 / PMC4522445)
• —The efficacy of video-assisted thoracoscopic surgery for anterior release and fusion in pediatric spinal deformity. (PMC3207578)
• —Video-assisted thoracoscopic surgery in idiopathic scoliosis: evaluation of the learning curve. (PMID 17413478)
• —Video-assisted thoracoscopic surgery for spinal conditions. (PMID 16565542)
• —Pioneering experience of uniportal video-assisted thoracoscopic surgery for anterior release of severe thoracic scoliosis. (PMC6972866)
• —Prospective pulmonary function evaluation following open thoracotomy for anterior spinal fusion in adolescent idiopathic scoliosis. (PMID 10984783)
• —Pulmonary function after less invasive anterior instrumentation and fusion for idiopathic thoracic scoliosis. (PMID 23965278 / PMC3765948)
• —Clinical analysis of video-assisted thoracoscopic spinal surgery in thoracic or thoracolumbar spinal pathologies. (PMC2588200)
• —Comparison of Scheuermann kyphosis correction by posterior-only fixation versus combined anterior/posterior fusion. (PMID 16985459)
• —Treatment approaches for Scheuermann kyphosis: a systematic review of historic and current management. (PMID 31675699)