Preventing adjacent segment disease after lumbar fusion: a new perspective emphasizing individualized factors

Area of Science:

• Spine surgery
• Orthopedics
• Degenerative spine disease

Background:

• Posterior lumbar interbody fusion (PLIF) effectively treats degenerative lumbar spine diseases.
• Postoperative adjacent segment disease (ASD) negatively impacts long-term prognosis and quality of life.
• The pathogenesis of ASD is complex, involving inflammation, muscle degeneration, biomechanics, and surgical factors.

Purpose of the Study:

• To analyze risk factors for ASD following PLIF.
• To provide clinical guidance for ASD prevention and management.

Main Methods:

• Retrospective analysis of 500 patients who underwent PLIF.
• Patients categorized into non-ASD (n=404) and ASD (n=96) groups.
• Logistic regression analyzed factors: neutrophil-to-lymphocyte ratio (NLR), muscle indices (PMI, MMI), fat infiltration (MFI), cage subsidence, pelvic incidence-lumbar lordosis mismatch, and nonunion.

Main Results:

• ASD incidence was 19.2%.
• Independent risk factors for ASD included elevated NLR, decreased psoas major muscle index (PMI) and multifidus muscle index (MMI), increased multifidus muscle fat infiltration rate (MFI), cage subsidence, and nonunion.
• While both groups improved, the non-ASD group showed greater functional recovery.

Conclusions:

• ASD after PLIF is associated with systemic inflammation, lumbar muscle degeneration, cage subsidence, and nonunion.
• Preoperative optimization of inflammatory status and lumbar muscle rehabilitation are crucial.
• Improved surgical techniques to prevent cage subsidence and promote bone fusion can reduce ASD incidence.