Biomechanical Comparison of Skip Laminectomy and Laminoplasty in the Lower Cervical Spine: An Experimental Study Using a Sheep Model.

STUDY

DESIGN

Controlled experimental biomechanical study using a sheep cervical spine model.

OBJECTIVE

To biomechanically evaluate and compare skip laminectomy and laminoplasty in the lower cervical spine, focusing on their influence on spinal stability.

SUMMARY OF BACKGROUND DATA: Skip laminectomy and laminoplasty are 2 posterior cervical surgical techniques widely used for spinal canal decompression. Although their clinical outcomes have been compared, no previous study has biomechanically analyzed and compared these techniques in the cervical region.

METHODS

Twenty-eight C2-T1 cervical spine specimens obtained from merino sheep were used in this study. Seven specimens underwent preliminary fracture testing to establish nondestructive loading parameters. The remaining specimens were assigned to 3 groups: intact control, laminoplasty, and skip laminectomy (n=7 per group). Bone mineral density (BMD) was measured to ensure baseline equivalence across specimens. Biomechanical testing was performed using an electromechanical actuator to evaluate displacement during flexion, extension, lateral bending, and axial rotation under standardized loading conditions. Statistical analysis was conducted to compare biomechanical behavior among the groups.

RESULTS

No statistically significant differences were observed among the control, laminoplasty, and skip laminectomy groups with respect to displacement during flexion (P=0.755), extension (P=0.546), right lateral bending (P=0.359), left lateral bending (P=0.415), or axial rotation (P=0.690). Both surgical techniques demonstrated biomechanical behavior comparable to that of intact cervical spine specimens under the tested loading conditions.

CONCLUSION

This study represents, to our knowledge, the first direct biomechanical comparison of skip laminectomy and laminoplasty in the cervical spine. Both procedures preserved immediate postoperative mechanical stability in this experimental ovine model, with no significant biomechanical differences identified between the techniques. Further biomechanical and long-term clinical studies are needed to determine the clinical relevance of these findings.