Microscopic and Biomechanical Analysis of PEEK Interspinous Spacers for Spinal Fusion Applications

Area of Science:

• Biomaterials Science
• Orthopedic Surgery
• Mechanical Engineering

Background:

• Spinal fusion surgery aims to unite vertebrae, often using intervertebral spacers.
• Polyetheretherketone (PEEK) is a common biocompatible material for these spacers due to its strength and longevity.
• Assessing the biomechanical properties of spinal implants is crucial for surgical success.

Purpose of the Study:

• To evaluate the biomechanical characteristics of two distinct intervertebral spinal fusion implants.
• To assess the chemical composition of the implants.
• To compare the performance of a subtractively manufactured implant against established benchmarks.

Main Methods:

• Standardized mechanical testing was conducted on two intervertebral implant designs at a velocity of 2 mm/min.
• Stopping criteria for mechanical tests were based on the 50th percentile load.
• Raman spectroscopy was employed to determine the chemical composition of the implant materials.

Main Results:

• The subtractively manufactured implant exhibited a significant change in its elastic region at 1300 N.
• Subsidence of the implant began when subjected to a load of 1500 N.
• Mechanical and chemical analyses provided insights into implant performance.

Conclusions:

• The biomechanical evaluation of spinal implants is enhanced by integrating mechanical testing with microscopic characterization.
• Understanding the mechanical limits of implants, such as the onset of subsidence, is vital for patient safety.
• This study contributes to the ongoing development of effective spinal fusion devices.