Incidence, Risk Factors, and Prevention Strategy for Proximal Junctional Kyphosis in Adult Spinal Deformity Surgery

Area of Science:

• Spine surgery
• Orthopedics
• Radiographic analysis

Background:

• Proximal junctional kyphosis (PJK) is a complication of adult spinal deformity (ASD) surgery.
• Proximal junctional failure (PJF) may necessitate re-operation.
• Causes and prevention of PJK are not well understood.

Purpose of the Study:

• To identify differences between patients who develop PJK and those who do not after ASD surgery.
• To investigate risk factors associated with PJK development.

Main Methods:

• Retrospective analysis of 86 patients undergoing ASD surgery (2012-2018).
• Comparison of demographic, clinical, and radiographic parameters between PJK and non-PJK groups.
• Evaluation of spinopelvic parameters including pelvic incidence minus lumbar lordosis (PI-LL), pelvic tilt (PT), and thoracic kyphosis (TK).

Main Results:

• No significant differences in demographics or preoperative parameters.
• Lower postoperative PI-LL and pelvic tilt (PT), and higher thoracic kyphosis (TK) were observed in the PJK group.
• PJF occurred in 17.5% of the PJK group, associated with older age, higher TK, and lower SRS-22 satisfaction scores.

Conclusions:

• Lower postoperative PI-LL (≤0°) is a risk factor for PJK.
• Maintaining a PI-LL >0° postoperatively is crucial for PJK prevention strategies in ASD surgery.