Adjacent segment degeneration in the lumbar spine

Area of Science:

• Spine surgery
• Orthopedics
• Degenerative spine disease

Background:

• Posterior lumbar arthrodesis can lead to adjacent segment degeneration (ASD).
• Long-term studies on both cephalad and caudad ASD after posterior lumbar fusion are limited.
• This study investigates ASD rates and adjacent motion segment survival post-posterior lumbar fusion.

Purpose of the Study:

• To determine the incidence and progression of adjacent segment degeneration following posterior lumbar arthrodesis.
• To analyze the survival rates of motion segments adjacent to the fusion site.
• To identify factors influencing adjacent segment degeneration.

Main Methods:

• Retrospective analysis of 215 patients undergoing posterior lumbar arthrodesis.
• Radiographic assessment of arthritic degeneration at adjacent levels preoperatively and at follow-up (average 6.7 years).
• Kaplan-Meier survival analysis and correlation analysis were used.

Main Results:

• 27.4% of patients showed adjacent segment degeneration requiring further surgery (decompression or arthrodesis).
• Predicted rates of symptomatic ASD requiring surgery were 16.5% at 5 years and 36.1% at 10 years.
• No significant correlation found between preoperative grade and need for surgery, or fusion length.

Conclusions:

• Symptomatic adjacent segment degeneration requiring intervention occurs at significant rates post-lumbar fusion.
• The ten-year rate of symptomatic ASD requiring surgery is predicted at 36.1%.
• Fusion length and preoperative adjacent segment degeneration grade did not appear to correlate with the need for subsequent surgery.