Abstract
In adult spinal deformity (ASD) patients with a compensatory decrease in thoracic kyphosis (TK), both TK and the PJA (proximal junctional angle) increase postoperatively following surgery for restoration of lumbar lordosis. According to existing definitions this postoperative PJA progression is classified as PJK (proximal junctional kyphosis), but in ASD how does the magnitude of this progression correlate to the incidence of proximal junctional failure (PJF)? We retrospectively reviewed pre- and post-operative radiographs of 40 patients with ASD (mean age, 68.5 years) who underwent corrective spinal surgery (from T10 to sacrum and ilium) in our institution for lumbar kyphotic deformity. From these we compared two sub-groups where the P (positive) group (16 cases) had a preoperative PJA≥5°, and the N (negative) group (8 cases) had a preoperative PJA≤-5°. The preop to final follow-up PJA change was significantly greater in the N group than in the P group, but no other differences were found in other sagittal plane radiographic parameters, or HRQOL, or the incidence of PJK and PJF. In spinal deformity patients with compensatory thoracic lordosis, the preoperative PJA does not correlate to the incidence of junctional failure such as PJK or PJF.
