Posterior Spinal Fusion with Ponte Osteotomies (AIS)

Ponte osteotomies are posterior osteotomies — cuts made at the back of the spine, at several levels across the curve, that remove the small joints and ligaments between the vertebrae. Doing this mobilises and shortens the back of the spine, which allows it to hinge and correct more freely. When they are combined with a standard posterior spinal fusion using pedicle screws, they give me more control over the shape of the spine, and in particular they let me build in a thoracic kyphosis — restoring the normal forward curve of the upper back that scoliosis, and powerful screw correction, can flatten. All of this is done through the back, in a single approach.

I reach for Ponte osteotomies in two main situations. The first is the moderately stiff curve — a curve that has some stiffness and some flatness of the upper back, but is not so rigid that it needs a full anterior release through the chest. In that setting, Ponte osteotomies give me much of the flexibility and much of the kyphosis-restoring benefit of an anterior release, but from the back alone and without entering the chest. So I often use them when a curve is not severe enough to require an anterior release.

The second situation is the partially mobile or previously operated spine. A particular example is the conversion of magnetically controlled growing rods to a definitive fusion. A spine that has been under growing rods for years is often partly stiffened, having begun to fuse on its own. When I take such a spine to its final fusion and the spine is only partially mobile, Ponte osteotomies let me re-mobilise it, restore thoracic kyphosis, and improve the final correction, again all from the back.

The osteotomies are made as part of the posterior fusion. Once the back of the spine has been mobilised by the cuts, I use the pedicle screws and rods to correct the curve into a balanced, level shape in both planes, deliberately building in the thoracic kyphosis I want, and then bone graft is laid so the spine fuses solidly over the following months. Because the osteotomies involve working close to the spinal cord, the nerves are monitored particularly carefully throughout. The whole procedure remains a single, posterior operation.

The evidence supports Ponte osteotomies primarily for their sagittal benefit. In hypokyphotic — flattened — curves, adding Ponte osteotomies produces a meaningful gain in thoracic kyphosis compared with fusion alone, and improves apical derotation, while the extra gain in the side-to-side (coronal) correction is generally modest. The recognised trade-offs are somewhat greater blood loss and operating time, and a higher rate of intraoperative neuromonitoring alerts, which have not translated into more permanent problems when properly managed. Because modern pedicle-screw constructs combined with Ponte osteotomies confer substantial flexibility, they are frequently used in place of an anterior release for curves that are moderately stiff but not truly rigid, with anterior release kept for the very largest, most inflexible curves. In previously operated spines — including conversion of growing rods to definitive fusion — osteotomies are commonly added to re-mobilise a spontaneously stiffening spine and improve the final result.

Because this is a posterior operation, recovery follows that of a standard posterior fusion: a hospital stay of several days, active pain relief, help to get up and walk within a day or two, and a graded return to normal life over the following months while the fusion becomes solid. Many young people notice a more natural shape to the upper back, since restoring thoracic kyphosis is one of the aims of adding the osteotomies. Strenuous activity and contact sport are limited during healing, and the fused part of the spine will feel stiff while the rest continues to move. The spine is followed up over the long term.

• —Do hypokyphotic AIS patients treated with Ponte osteotomy obtain better clinical efficacy? (PMID 36384684 / PMC9670489)
• —Multilevel Ponte osteotomy with posterior selective segmental pedicle screws for thoracic AIS. (PMC6267836)
• —Halanski MA, et al. Do multilevel Ponte osteotomies improve curve correction and restore thoracic kyphosis? (PMID 22198324)
• —Ponte osteotomies in AIS: systematic review and meta-analysis of comparative studies. (PMC10814379)
• —Posterior column osteotomies in adolescent idiopathic scoliosis (review). (PMC12088245)
• —Ponte osteotomies with pedicle screw instrumentation in the treatment of AIS. (PMID 27927293)
• —Do Ponte osteotomies enhance correction in AIS? Analysis of 191 Lenke 1A and 1B curves. (PMID 27927535)
• —Ponte osteotomies increase risk of intraoperative neuromonitoring alerts in AIS surgery. (PMID 35509562 / PMC9062905)
• —Effects of Ponte osteotomy on vertebral rotation in idiopathic scoliosis: scoping review. (PMC12764732)
• —Modified Ponte osteotomy using an ultrasonic bone scalpel: time and blood loss. (PMC11845863)
• —Two-stage posterior surgery using a temporary magnetically controlled growing rod for severe rigid AIS. (PMC12718158)
• —Is final fusion necessary for growing-rod graduates? Systematic review and meta-analysis. (PMC9837500)
• —Anterior release and posterior spinal fusion vs posterior-only fusion in AIS with large-magnitude thoracic curves. (PMC12872680)