Abstract
Introduction
Proximal junctional kyphosis (PJK) is a well-known complication following long posterior spinal fusion (PSF) for adult spinal deformity and occurs in 9–46% of surgeries. A subset of these develop proximal junctional failure, resulting in a 26–39% revision rate within the first six months postoperatively. Risk factors for development of PJK include age > 55, osteopenia, and global sagittal imbalance. We have previously described a technique for prophylactic vertebroplasty to minimize the incidence of PJF/PJK for long-segment thoracolumbar fusion surgery. Here, we present the results of this technique at five year follow-up.
Material and Methods
We reviewed clinical and radiographic data for 41 adult patients treated with PSF that received prophylactic vertebroplasty at the upper instrumented vertebra and supra-adjacent vertebrae. PJK was defined as a change in the PJK angle ≥10 degrees between the immediate post-operative and the final follow-up radiograph. PJF was defined as proximal junctional fracture, fixation failure, or kyphosis that required extension of the fusion.
Results
There were 5 males and 36 females. Average age at the time of initial surgery was 65.6 years (range, 41–87). 33 patients had complete five year follow-up radiographic and clinical data available and were included in the analysis. The average follow-up was 72.3 months (range, 34–124). 30.3% developed PJK (10/33), not requiring revision surgery. 9.1% developed PJF (3/33) requiring revision surgery, and extension of fusion. Of the three patients that developed PJF requiring revision surgery, none had junctional fractures that could explain the PJF. One developed PJF within six weeks of the initial surgery, one three years after, and one five years after. None of the 33 patients had evidence of vertebral fractures adjacent to cement augmented vertebrae. Health related quality of life (HRQoL) data was available for 30 patients at five year follow-up. There was no significant difference in Oswestry Disability Index, Short Form 36, or SRS-22 scores between those with and without PJK/PJF (P > 0.05 for all comparisons). Mean coronal alignment was comparable between patients who developed PJK/PJF (19 mm) and those who did not (20 mm) (p = 0.64). Mean sagittal alignment was more positive in patients who developed PJK/PJF (97 mm) compared with those who did not (79 mm), but this was not significant (p = 0.42). There were no significant differences in thoracic kyphosis (p = 0.39) or lumbar lordosis (p = 0.93) between the two groups.
Conclusion
The incidence of PJK was 30.3% and the incidence of PJF was 9.1% at five year follow-up. There were no junctional fractures in this population, and no clinically significant long term complications from the use of vertebroplasty. Prophylactic vertebroplasty in long PSF for adult spinal deformity is a safe and effective method to minimize the incidence of PJF.