Radiographic and Clinical Outcomes of Transverse Process Hook Placement at the Proximal Thoracic Upper Instrumented Vertebra in Adult Spinal Deformity Surgery.

TPH placement at the proximal thoracic UIV for long fusion showed favorable clinical and radiographic outcomes in terms of the incidence of PJK and mean PJK angle at mean 44-month follow-up. TPHs placed in the proximal thoracic UIV were in stable position in 75% of patients. Compression fracture at UIV-1 was the most common pattern of PJK. PJK angle progression was greater in revision cases and in patients with greater preoperative thoracic kyphosis.