Posterior strut fusions to enhance immediate postoperative cervical stability

Area of Science:

• Orthopedic Surgery
• Spinal Fusion Techniques
• Biomedical Engineering

Background:

• Posterior interspinous fusion constructs require enhanced immediate stability.
• Current methods may have limitations in achieving optimal stability.
• Investigating novel strut materials for spinal fusion is crucial.

Purpose of the Study:

• To evaluate the immediate stability of posterior interspinous fusion constructs.
• To compare ulna struts versus metallic struts for spinal fusion in a canine model.
• To assess the biomechanical and histological outcomes of different fixation methods.

Main Methods:

• Twenty-four adult mongrel dogs underwent posterior C4-C5 fusion.
• Iliac crest autogenous graft with internal fixation using ulna or metallic struts and sublaminar wires.
• Radiological, mechanical, and histological analysis at 1 week and 3 months postoperatively.

Main Results:

• Both ulna and metallic strut fusions demonstrated immediate and 3-month stability comparable or superior to normal canine spinal segments.
• The surgical procedures resulted in a significant rate of neurologic complications, including complete and incomplete quadriplegia in five dogs.
• Histological and mechanical assessments confirmed successful fusion in the stabilized segments.

Conclusions:

• Posterior spinal fusion with ulna or metallic struts provides significant biomechanical stability.
• The high incidence of neurologic injury in this canine model raises serious safety concerns.
• These techniques are cautiously recommended only for patients with complete quadriplegia due to the risk of neurological damage.