Associate professor of biomedical engineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA
Assistant professor, University of Pennsylvania Medical School, University of Pennsylvania, Philadelphia, PA
Pages: 12 Published: Jan 1987
Bone stock deficiency is a major challenge encountered in the revision of failed hip arthroplasties. Loosening of the prosthetic components under aseptic conditions results in the loss of trabecular and cortical bone. At revision the surgeon is frequently faced with a thin smooth cortical tube with an almost complete absence of endosteal trabecular bone. Consequently, fixation of the revision component is seriously compromised. The objective of the present paper is to address this issue specifically by discussing a new concept in materials created to alleviate this major problem of deficient bone stock. The authors propose using a porous flexible titanium material to fill void spaces in the deficient bone structure. The material can easily be shaped at the time of surgery and has a pore size in the optimum range for bone ingrowth (100 to 600 µm). In addition, it is possible to infiltrate it with bone cement. Furthermore, the elastic properties of this material closely correspond to those of trabecular bone.
The objective in the design of this new material was to improve the current practice of revision surgery in three problem areas: first, by avoiding brittle fracture due to excess cement thickness; second, by decreasing the risk of disuse atrophy caused by large prosthesis stem sizes; and third, by filling the excess cavity with a material with elastic properties matching those of the missing tissue.
porous implants, titanium, elastic properties, bony ingrowth, cement penetration, metal fibers
Paper ID: STP25242S