Bone cement penetration pattern and primary stability testing in keeled and pegged glenoid components

Area of Science:

• Orthopedic Surgery
• Biomaterials Science
• Radiology

Background:

• Bone mineral density (BMD) is hypothesized to influence cement penetration in arthroplasty.
• This study investigated the correlation between BMD and cement penetration in cemented glenoid components.
• The influence of implant design on cement penetration was also examined.

Purpose of the Study:

• To determine the correlation between bone mineral density and cement penetration in cemented glenoid components.
• To assess the impact of implant design (keeled vs. pegged) on cement penetration.
• To evaluate the pull-out strength and primary stability of different glenoid component designs.

Main Methods:

• BMD was measured in 10 pairs of scapulas.
• Micro-computed tomography (micro-CT) was used to analyze cement penetration after implantation of keeled and pegged glenoid components.
• A third-generation cementing technique with a vacuum mixing system was employed.
• Pull-out strength testing was conducted to assess primary stability.

Main Results:

• A strong negative correlation was found between BMD and mean cement penetration for both pegged (R² = -0.83) and keeled (R² = -0.81) glenoid components.
• Mean cement penetration was significantly greater in the pegged group (113.9 mm²) compared to the keeled group (78.4 mm²).
• While components detached from the cement mantle, bone-cement interfaces remained intact, with higher pull-out strength observed for keeled components (1093N) versus pegged components (884N).

Conclusions:

• Modern cementing techniques are crucial for achieving deep bone-cement bonding and preventing glenoid component loosening.
• The findings highlight the importance of considering BMD and implant design in cemented glenoid arthroplasty.
• These results are particularly relevant for patient selection in cases of poor bone quality, such as osteoporosis or rheumatoid arthritis.