Risk factors for adjacent segment degeneration after PLIF

Area of Science:

• Spine surgery
• Degenerative spine disease
• Adjacent segment degeneration

Background:

• Posterior lumbar interbody fusion (PLIF) with pedicle screw fixation is effective for L4 degenerative spondylolisthesis.
• Solid fusion may accelerate degeneration at adjacent spinal levels, particularly the cranial level.
• Risk factors for adjacent segment degeneration after PLIF remain unclear.

Observation:

• A retrospective study analyzed 87 patients undergoing PLIF for L4 degenerative spondylolisthesis with at least 2 years of follow-up.
• Patients were categorized based on L3-L4 segment degeneration progression and neurologic status.
• Radiologic parameters including lumbar lordosis, scoliosis, laminar inclination, facet sagittalization, facet tropism, and disc degeneration were assessed.

Findings:

• No significant correlation was found between radiologic degeneration of the cranial adjacent segment and clinical results.
• Individual preoperative radiologic factors did not predict postoperative degeneration.
• Coexistence of horizontalization of the lamina at L3 and facet tropism at L3-L4 was associated with neurologic deterioration and the need for further surgery.

Implications:

• While radiologic degeneration alone doesn't predict clinical outcomes after PLIF, specific preoperative findings may indicate higher risk.
• Identifying patients with lamina horizontalization and facet tropism is crucial for predicting neurologic deterioration due to accelerated adjacent segment degeneration.
• Further research into these specific risk factors could refine surgical planning and patient management for degenerative spondylolisthesis.