Anterior Riew osteotomy

An osteotomy through the cervical disc space and uncovertebral joints back to the level of the transverse foramen bilaterally

The neck is prepped and draped.
Operating microscope
Use standard Smith-Robinson approach, with fluoroscopy used to confirm levels.
Special care is taken to expose the kyphosis apex, which may be significantly deeper.
Longus colli muscles

Are detached and stripped
Often transected in kyphotic patients as they contribute to neck flexion, with careful avoidance of the sympathetic chain.

Anterior osteophytes are removed using a Leksell rongeur to facilitate disc space exposure.

Caspar pins are placed into the vertebral body at the level of the intended osteotomy.

These pins should be placed perpendicular to the anterior wall of the vertebral body, which may result in divergent pins, but is crucial for achieving lordosis upon distraction

The osteotomy is performed using a high-speed 2.5 mm matchstick burr.
The bony resection should be perpendicular to the spine in the same plane as the disc space to ensure symmetric resection.
For combined coronal and kyphotic deformities, the bony resection can be asymmetric for tailored alignment correction.
The osteotomy is carried back to the PLL across the disc space and laterally up to the uncovertebral joints.

This is performed in a careful to avoid vertebral artery injury.
A combination of upgoing curette and Penfield No. 4 dissector is used to expose the lateral uncinate process.
Critically, a Penfield No. 2 dissector is inserted lateral to the uncinate process to protect the vertebral artery during drilling
A thin rim of bone is initially left laterally for protection and then carefully removed with a curette.
Once the nerve root is identified, foraminotomy is completed using curettes to definitively decompress the exiting nerve root and complete the osteotomy.

After the osteotomy is complete bilaterally back to the neural foramen, the sheets or padding under the patient's head are slowly and sequentially removed.

Simultaneously, the surgeon applies gentle downward pressure on the patient's forehead

This method maximises biomechanical leverage and minimises the risk of Caspar pin loosening or vertebral body fracture.

Sequentially larger disc space spreader (starting with 5-mm height) are gently rocked cranially and caudally in the disc space while pushing down on the forehead

Once the back of the head rests on the operating table, the anterior kyphosis correction is generally complete.

If more lordosis is needed, a folded sheet can be placed under the patient's shoulder to elevate the head further.

Additional weight (up to 25 lbs.) can be added to the Gardner-Wells tongs to maintain the desired correction.

In patients with previous posterior fusion or instrumentation, partial correction of the deformity can generally be achieved since the posterior fusion mass will flex a few degrees, although 3.5 mm cobalt chromium rods pose the greatest challenge given their rigidity and strength

Bone graft (typically cancellous) is inserted into the distracted osteotomy site.

The largest possible graft should be used to maximise surface area and structural support due to the high likelihood of graft subsidence.

If full correction is achieved, an anterior cervical plate with fixed angle screws is placed.

If additional posterior releases are planned, a trapezoid-shaped bone graft is used, contacting only the anterior osteotomy site to allow for further lordosis.

A standalone cage fixed with a single screw, or an interference screw/buttress plate, can prevent graft extrusion during the posterior stage.

Hemostasis is obtained.
A Penrose drain is recommended over a closed-suction drain to prevent occlusion and allow manual hematoma expression.
Immediate posterior fixation is recommended; if delayed, a halo or rigid cervical collar is used.