Deformation of the Durom cup after impaction: a cadaver study / 中华骨科杂志

ABSTRACT

ObjectiveTo explore the magnitude of the deformation of Durom cup after press-fit implantation in cadaver models and to investigate which part of the cup would deform the most.Methods Three fresh adult cadaver pelves were harvested and were cleaned of soft tissue,preserving the sacrospinous and sacrotuberous ligaments.Bilateral acetabular replacements in all cadaver pelves were performed by a senior surgeon.All acetabulums were reamed with corresponding reamers,and the direction of reaming was 40°to 45° of abduction and 15° to 20° of anteversion.Larger reamers were used sequentially until the anterior and posterior walls were firmly engaged.Six Durom cups were implanted.The deformation of each cup was detected by 3D Digital Image Correlation (3D DIC) method,and the magnitude and the parts of the deformation were recorded.ResultsThe diameters of cups were 50 mm in 2,52 mm in 2 and 54 mm in 2,respectively.All cups generated different degree of deformation,which were mostly located in the posterior-superior quadrant and the areas of the ramus of ischium.After measuring the maximum deformed areas for three times,it was found that the localized depression deformation occurred in all cups.The average deformation value was (41.73±8.86) μm (range,29.91-49.43 μm).There was no significant change in deformation value 24 hours after press-fit implantation and 7 days after removing the cups.ConclusionDurom large diameter metal acetabular component will generate deformation during the press-fit implantation.And the deformation may play an important role in more wear and more ions release.