Objective:

To evaluate the effects of laminotomy and total flavectomy on displacement and stiffness in a lamb lumbar spine model, specifically comparing the two procedures under various loading conditions.

Key Findings:

• Total flavectomy resulted in significantly increased displacement in axial compression (p = 0.001), left bending (p = 0.001), flexion (p < 0.001), and extension (p = 0.003) compared to controls.
• Stiffness was significantly reduced in left bending (p < 0.001), flexion (p = 0.004), and extension (p = 0.016) in the Laminotomy + Flavectomy group.
• Isolated laminotomy caused only minor, non-significant changes in most planes.

Interpretation:

Total removal of the LF significantly increases motion and decreases stiffness, indicating its essential role in maintaining posterior tension band stability, which has important implications for surgical practice.

Limitations:

• The study was conducted in an ex vivo lamb spine model, which may not fully replicate human spinal biomechanics, potentially limiting clinical applicability.
• The sample size was limited to 24 spinal units, which may affect the generalizability of the findings.

Conclusion:

Total flavectomy substantially compromises segmental stability compared to laminotomy alone, suggesting that LF-preserving strategies should be prioritized when feasible to minimize the risk of postoperative instability.