The mixed clinical performance of polymethylmethacrylate bone cements has led to widespread application of "press-fit" or porous ingrowth procedures. One to three millimeter gaps between bone and implants in these "cementless" procedures are believed to contribute to implant loosening, progressive thigh pain, and clinical failure. A new calcium phosphate cement ("Superbone") used in combination with these "cementless" total hip prostheses, would initially stabilize the implant by filling gaps at bone-implant surface interfaces, and subsequently encourage bone ingrowth as the "grout" is resorbed. The present research project will investigate basic biological responses to different calcium phosphate cement formulations. Bone ingrowth infiltration into the cements will be compared with "cementless" controls. A key parameter of interest is how fundamental chemical, crystallographic, and microstructural parameters influence rate of resorption of the calcium phosphate cements and the corresponding influence on rate of bone ingrowth. Data generated from this study will help evaluate the potential of this new biomaterial for other clinical applications in the spine, head and neck, and appendicular skeleton.The potential commercial application as described by the awardee: SuperBone could find potential uses in approximately 180,000 total hip arthroplasty procedures annually worldwide if it were on the market today. The cost to the hospital could range from $250 to $1,000 per treatment. As a general bone defect filler, SuperBone could potentially supplant a present domestic U.S. market of 25M for conventional bone cements.
