Spinal Osteotomies

What it is

An osteotomy is a controlled cut in bone that allows a stiff segment of the spine to be repositioned. In spinal deformity surgery, osteotomies are used when the spine is too rigid or too far out of alignment for a standard fusion to correct. Closing the cut realigns the spine, which is then held in position with rods and screws over multiple levels.

The two types used most often are:

Posterior column osteotomy (PCO): the facet joints at the back of the vertebra are removed at one or more levels, letting the back of the spine close like a hinge. Each level gives a modest amount of correction, and several can be combined for a larger effect. The disc space stays intact, which makes this the workhorse for flexible or moderately stiff deformities.

Pedicle subtraction osteotomy (PSO): a wedge of bone is removed through the pedicles and the vertebral body itself, then the wedge is closed. A single PSO can correct roughly 25 to 35 degrees of fixed forward deformity — a much larger correction through a much larger operation.

When it may be considered

Spinal osteotomies are reserved for selected patients with rigid spinal deformity — most often adult sagittal imbalance, where the spine has lost its natural curve and the person leans forward. Symptoms can include difficulty standing upright, back fatigue from fighting gravity, and pain. The decision rests on full-length standing X-rays with measurements of spinal balance, the stiffness of the curve, and whether symptoms persist after thorough conservative care. Osteotomies are always combined with long-segment instrumented fusion; they are not standalone procedures.

What to discuss at consultation

• Goals: restore upright alignment and reduce the pain and fatigue caused by spinal imbalance.
• Alternatives: continued nonoperative care; a fusion without osteotomy when the deformity is flexible enough to correct without bone cuts.
• Recovery: this is major surgery — expect a hospital stay of several days and a structured rehabilitation period, with bone healing measured in months.
• Risks: neurologic injury, significant blood loss, incomplete correction, instrumentation problems, nonunion (failure of the bone to fuse), junctional problems above or below the construct, and general medical risks.