Distal Junctional Failure: A Feared Complication of Multilevel Posterior Spinal Fusions

Area of Science:

• Spine Surgery
• Orthopedics
• Spinal Deformity

Background:

• Distal junctional failure (DJF) is an under-recognized complication following posterior spinal fusion, particularly in adult spinal deformity (ASD) surgery.
• Understanding risk factors for DJF is crucial for improving surgical outcomes and reducing revision rates.

Purpose of the Study:

• To describe a case series of patients experiencing DJF after posterior spinal fusion.
• To analyze the association between sagittal spinopelvic alignment and DJF.
• To identify potential risk factors for DJF in adult spinal deformity surgery.

Main Methods:

• Retrospective review of 19 patients undergoing revision surgery for DJF between 2009 and 2019.
• Collection of demographic and surgical data, including upper-instrumented vertebra (UIV) and lowest instrumented vertebra (LIV).
• Radiographical assessment of sagittal and coronal alignment pre- and postoperatively.

Main Results:

• 84.2% of patients had at least one known DJF risk factor.
• Common lowest instrumented vertebrae (LIV) were L5 (n=10) or S1 (n=2).
• DJF causes included vertebral fracture, screw pull-out, stenosis, and instability; revision complications involved similar mechanical failures.

Conclusions:

• Insufficient sagittal balance, female gender, osteoporosis, and L5/S1 LIV in long constructs are associated with DJF.
• Restoring spinal balance and achieving circumferential fusion at the construct base are key preventive strategies.
• These findings aid in optimizing surgical planning to minimize DJF and the need for revision surgery.