Biomaterial Database

Early cement damage around a femoral stem is concentrated at the cement/bone interface. 2003

Amos Race, and Mark A Miller, and David C Ayers, and Kenneth A Mann

Musculoskeletal Science Research Center, Institute for Human Performance, SUNY Upstate Medical University, 750 East Adams Street, Syracuse, NY 13210, USA. racea@upstate.edu

This study aimed to improve understanding of the mechanical aspects of cemented implant loosening. After aggressive fatigue loading of stem/cement/femur constructs, micro-cracks and stem/bone micro-motions were quantified to answer three research questions: Are cracks preferentially associated with the stem/cement interface, the cement/bone interface or voids? Is cement damage dependent on axial position? Does cement damage correlate with micro-motion between the stem and the bone? Eight Charnley Cobra stems were implanted in cadaveric femora. Six stem/cement/femur constructs were subjected to "stair-climbing" loads for 300 kcycles at 2Hz. Loads were normalized by construct stiffness to avoid fracture. Two additional constructs were not loaded. Transverse sections were cut at 10mm intervals, stained with a fluorescent dye penetrant and examined using epi-fluorescence stereomicroscopy. Crack lengths and cement areas were recorded for 9 sections per specimen. Crack length-density was calculated by dividing summed crack length by cement mantle area. To isolate the effect of loading, length-density data were offset by the baseline length-density measured in the non-loaded specimens. Significantly more cracks were associated with the interdigitated area (35.1%+/-11.6%) and the cement/bone interface (31.0%+/-6.2%) than with the stem/cement interface (11.0%+/-5.2%) or voids (6.1%+/-4.8%) (p<0.05). Load-induced micro-crack length-density was significantly dependent on axial position, increasing proximally (p<0.001). Micro-motions were small, all stems rotated internally. Cement damage did not correlate with micro-motion.

UI	MeSH Term	Description	Entries
D008856	Microscopy, Fluorescence	Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.	Fluorescence Microscopy,Immunofluorescence Microscopy,Microscopy, Immunofluorescence,Fluorescence Microscopies,Immunofluorescence Microscopies,Microscopies, Fluorescence,Microscopies, Immunofluorescence
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D009038	Motion	Physical motion, i.e., a change in position of a body or subject as a result of an external force. It is distinguished from MOVEMENT, a process resulting from biological activity.	Motions
D011475	Prosthesis Failure	Malfunction of implantation shunts, valves, etc., and prosthesis loosening, migration, and breaking.	Prosthesis Loosening,Prosthesis Durability,Prosthesis Migration,Prosthesis Survival,Durabilities, Prosthesis,Durability, Prosthesis,Failure, Prosthesis,Failures, Prosthesis,Loosening, Prosthesis,Loosenings, Prosthesis,Migration, Prosthesis,Migrations, Prosthesis,Prosthesis Durabilities,Prosthesis Failures,Prosthesis Loosenings,Prosthesis Migrations,Prosthesis Survivals,Survival, Prosthesis,Survivals, Prosthesis
D012016	Reference Values	The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.	Normal Range,Normal Values,Reference Ranges,Normal Ranges,Normal Value,Range, Normal,Range, Reference,Ranges, Normal,Ranges, Reference,Reference Range,Reference Value,Value, Normal,Value, Reference,Values, Normal,Values, Reference
D001843	Bone Cements	Adhesives used to fix prosthetic devices to bones and to cement bone to bone in difficult fractures. Synthetic resins are commonly used as cements. A mixture of monocalcium phosphate, monohydrate, alpha-tricalcium phosphate, and calcium carbonate with a sodium phosphate solution is also a useful bone paste.	Bone Cement,Bone Glues,Bone Pastes,Bone Glue,Bone Paste,Cement, Bone,Cements, Bone,Glue, Bone,Glues, Bone,Paste, Bone,Pastes, Bone
D002102	Cadaver	A dead body, usually a human body.	Corpse,Cadavers,Corpses
D002484	Cementation	The joining of objects by means of a cement (e.g., in fracture fixation, such as in hip arthroplasty for joining of the acetabular component to the femoral component). In dentistry, it is used for the process of attaching parts of a tooth or restorative material to a natural tooth or for the attaching of orthodontic bands to teeth by means of an adhesive.	Cementations
D005264	Femoral Fractures	Fractures of the femur.	Femoral Fracture,Fracture, Femoral,Fractures, Femoral
D006622	Hip Prosthesis	Replacement for a hip joint.	Femoral Head Prosthesis,Femoral Head Prostheses,Hip Prostheses,Prostheses, Femoral Head,Prostheses, Hip,Prosthesis, Femoral Head,Prosthesis, Hip