Presented in part at the Veterinary Orthopedic Society Meeting, Big Sky, MN, March 8–15, 2007 and ACVS Veterinary Symposium, the Surgical Summit, San Diego, CA, October 23–25, 2008.
Biomechanical Evaluation of Acetabular Cup Implantation in Cementless Total Hip Arthroplasty
Article first published online: 12 AUG 2010
© Copyright 2010 by The American College of Veterinary Surgeons
Volume 39, Issue 7, pages 818–823, October 2010
How to Cite
Margalit, K. A., Hayashi, K., Jackson, J., Kim, S. Y., Garcia, T. C., Wiggans, K. T., Aiken, S. and Stover, S. M. (2010), Biomechanical Evaluation of Acetabular Cup Implantation in Cementless Total Hip Arthroplasty. Veterinary Surgery, 39: 818–823. doi: 10.1111/j.1532-950X.2010.00726.x
- Issue published online: 1 OCT 2010
- Article first published online: 12 AUG 2010
- Submitted September 2009Accepted May 2010
Objective: To report biomechanical properties of the Biologic Fixation System (BFX) acetabular cup impacted into a normal canine pelvis and to compare the effect of implant positioned to and beyond the medial acetabular wall.
Study Design: In vitro cadaveric study.
Animals: Hemipelves of mature, large-breed dogs (n=6).
Methods: For each dog, 1 hemipelvis was reamed to the depth of the acetabular wall (group A) and 1 was reamed an additional 6 mm after penetration of the medial cortex of the acetabulum (group B). The hemipelves were implanted with acetabular cups and loaded in compression through a matching femoral prosthetic component until failure. Specimen stiffness, and failure displacement, load, and energy were determined from load and displacement data and results between groups compared with a paired t-test.
Results: Mean failure load was greater in group A (3812 ± 391 N) than group B (2924 ± 316 N; P<.014). No other differences (P>.05) were observed between groups. Bone fracture (n=5) and cup displacement (1) occurred in group A whereas in group B there were 3 fractures and 3 cup displacements.
Conclusions: Although medial placement of the BFX cup affected compressive failure loads, failure loads for both groups exceeded normal physiologic loads.
Clinical Relevance: Medial positioning of the acetabular cup does not appear to compromise acetabular implant-pelvic stability under normal physiologic loads. Because arthroplasty candidates often have abnormal acetabular architecture, mechanical properties of the cup placed in acetabula without a dorsal rim should be investigated.