title: Fixation of trapezial implants in a trapeziometacarpal total joint prosthesis tested in a model of porcine bone.
abstract: High aseptic loosening rates have been reported in total joint prostheses of the carpometacarpal joint of the thumb, particularly in the trapezial component. The primary fixation of new implants may be tested in cadaver bones, but the anatomy of the pig is in many ways similar to that of the human, so we compared the central carpal bone from the forefoot of 6-month-old pigs, which has a saddle joint surface similar to the trapezium, to the trapezium in patients with carpometacarpal osteoarthritis. The mean (SD) bone mineral density of the 13 pig forefoot bones was 0.88 (0.12) g/cm(2) compared with 0.63 (0.16) g/cm(2) in the 31 human trapeziums. The measured size of the porcine bones was slightly larger than that of the human trapeziums. The similarity in form, size, and bone mineral density means that the central bone of the forefoot of 6-month-old pigs may be used for fixation tests in trapezial implants.
authors.affiliation: The Orthopaedic Research Unit, Regional Hospital Holstebro, Holstebro, Denmark. tbhansen@dadlnet.dk
authors.forename: Torben Bæk
authors.initials: TB
authors.lastname: Hansen
authors.forename: David
authors.initials: D
authors.lastname: Hengst
authors.forename: Jesper
authors.initials: J
authors.lastname: Mortensen
authors.forename: Anders Læssøe
authors.initials: AL
authors.lastname: Amstrup
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D001696:Biomechanical Phenomena; D015519:Bone Density; D052737:Carpometacarpal Joints / Q000601:surgery*; D006801:Humans; D007595:Joint Prosthesis; D008875:Middle Aged; D023421:Models, Animal; D019919:Prosthesis Implantation / Q000009:adverse effects / Q000379:methods*; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D013314:Stress, Mechanical; D013552:Swine; D013718:Tensile Strength; D051222:Trapezium Bone / Q000601:surgery*