Upper thoracic pedicle screw fixation provides strong distal anchorage and supports cervical screws in posterior fusions. Individual anatomy varies widely with a generally decreasing transverse pedicle angle from T1 to T4.
After prone positioning, alignment should be verified by a lateral X-ray. After skin incision and dissection of paravertebral muscles, an osteotomy of the inferior part of the caudad facet joint might help to visualize anatomy and find the entry point for the pedicle screw which is at the junction of the bisected transverse process and the lamina at the lateral pars. The thoracic gearshift can be directed laterally in the beginning to avoid medial wall perforation, but should be pointed medially after 15–20 mm. If the surgeon has issues to insert the probe and therefore a screw in the pedicle, different salvage techniques are available which has to be emphasized as radiologic visualization by an image intensifier can be difficult in the upper thoracic spine.
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