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

Background It has been proposed that bone mineral density has an influence on cement penetration in hip and knee arthroplasty. The hypotheses of this study were that: 1) there is a negative correlation between bone mineral density (BMD) and cement penetration in cemented glenoid components; and 2) that implant design has an influence on cement penetration into the glenoid bone. Methods BMD of 10 pairs of fresh frozen scapulas was measured. Micro-computed tomography (micro-CT) scans in 3 different sections were analyzed after implantation of keeled and pegged glenoid components using a 3 rd -generation cementing technique with a vacuum mixing system. Cement penetration was analyzed and correlated with BMD. Pull-out strength testing was performed to analyze primary stability. Results The overall peak BMD was 0.6 [g/cm 2 ] (range, 0.33–0.98). A strong negative correlation between BMD and mean cement penetration was found for the peg ( R 2 = −.83; P R 2 = −.81; P 2 (range, 60.6–94.2) in the keel and 113.9 mm 2 (range, 78.2–143.4) in the peg group ( P P Conclusion A modern cementing technique, leading to a deep bonding between bone and cement, is crucial to prevent loosening of glenoid components. The findings of this study might help us to better understand the results of follow-up studies of cemented glenoid implants. Our results could be helpful for the choice of implants in patients with poor bone quality like osteoporosis or rheumatoid arthritis.