Recurrent Proximal Junctional Kyphosis

Abstract

Proximal junctional kyphosis (PJK) is one of the most common radiographic forms of adjacent segment degeneration with an incidence as high as 50% in adult spinal deformity surgery. It is a multifactorial problem with much still to be learned about the etiology and the most efficacious prevention methods. The challenge of addressing PJK can certainly be amplified in patients that develop recurrent proximal junctional kyphosis (rePJK) after revision surgery for PJK, which occurs in up to 45% of revision PJK cases. Patients found to be at the greatest risk for rePJK are those that have a pelvic tilt change >5 degrees, sagittal vertical axis change >50 mm, pedicle screw fixation at the upper instrumented vertebra and a preoperative cervicothoracic sagittal vertical axis of >40 mm. Often, factors that placed the patient at high risk for PJK following the initial surgery are still present such as compromised paraspinal musculature, poor bone quality and high overall frailty. This might account for the higher rates of surgical revision in cases of rePJK. At present, we are in need of a good method for addressing issues related to these patient characteristics. An overview of the challenge of rePJK and our current understanding of the complication is presented.