Anterior spinal fixation after lumbar corpectomy. A study in dogs

Area of Science:

• Spinal surgery
• Orthopedic research
• Biomedical engineering

Background:

• Lumbar burst fractures often require surgical intervention.
• Corpectomy is a common treatment, but achieving stable fusion can be challenging.
• Existing fusion techniques may have limitations in providing adequate stability.

Purpose of the Study:

• To evaluate the efficacy of anterior instrumentation in promoting fusion and stability for lumbar burst fractures treated with corpectomy.
• To compare the fusion rates and biomechanical properties of different surgical techniques in an animal model.
• To assess the safety and vertebral response to instrumentation.

Main Methods:

• Development of an unstable lumbar burst fracture model in 21 dogs, treated with corpectomy.
• Group I (Control): Biodegradable polymer spacer for fusion failure.
• Group II: Anterior arthrodesis with autogenous ulnar strut (no instrumentation).
• Group III: Anterior arthrodesis with ulnar strut and Kaneda instrumentation.
• Analysis at 24 weeks included fusion rate, biomechanical rigidity, neuropathology, and histomorphometry.

Main Results:

• Group III (Kaneda instrumentation) demonstrated a significantly higher fusion rate compared to Group I and Group II.
• Spinal biomechanical analysis showed Group III had increased torsional stiffness.
• No significant differences in neuropathological changes were observed between groups.
• Histomorphometric analysis revealed no device-related osteopenia; increased trabecular density was noted in instrumented vertebrae.

Conclusions:

• Anterior Kaneda instrumentation, combined with an ulnar strut, is effective in enhancing fusion rates and biomechanical stability for lumbar burst fractures.
• The instrumentation did not induce significant adverse vertebral responses like osteopenia.
• This technique offers a promising solution for achieving solid fusion in complex spinal reconstructions.