title: What humeri are suitable for comparative testing of suture anchors? An ultrastructural bone analysis and biomechanical study of ovine, bovine and human humeri and four different anchor types.
abstract: For testing of fixation devices such as suture anchors used in rotator cuff repair often animal bones are used. They are easily obtained, inexpensive and some have been found to be similar to human bone. But can we rely on the results drawn from these studies in our daily surgical practice? The purpose of this study was to compare the trabecular bone mineral density, the trabecular bone volume fraction and the cortical layer thickness in the greater tubercle in different species to evaluate their influence on primary stability of suture anchors under a cyclic loading protocol representing the physiologic forces placed on rotator cuff repairs in vivo. Bovine and ovine humeri are not suitable for suture anchor testing. The statistical significances for pullout forces between the anchors varied from species to species. Therefore, no very applicable information can be obtained from testing suture anchors in ovine or bovine humeri with regard to ultimate failure loads in human humeri. The ultimate failure load seems to depend mainly on the cortical thickness and on the subcortical trabecular bone quality.
authors.affiliation: Department of Orthopaedics, Campus Grosshadern, Ludwig-Maximilians-University Munich, Marchioninistr. 15, 81377 Munich, Germany. peter.mueller@med.uni-muenchen.de
authors.forename: Matthias F
authors.initials: MF
authors.lastname: Pietschmann
authors.forename: Andreas
authors.initials: A
authors.lastname: Hölzer
authors.forename: Christine
authors.initials: C
authors.lastname: Rösl
authors.forename: Andreas
authors.initials: A
authors.lastname: Scharpf
authors.forename: Thomas
authors.initials: T
authors.lastname: Niethammer
authors.forename: Volkmar
authors.initials: V
authors.lastname: Jansson
authors.forename: Peter E
authors.initials: PE
authors.lastname: Müller
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D001182:Arthroscopy; D001696:Biomechanical Phenomena; D015519:Bone Density; D001851:Bone Diseases, Metabolic / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D002417:Cattle; D005260:Female; D006801:Humans; D006811:Humerus / Q000000981:diagnostic imaging / Q000502:physiology / Q000601:surgery* / Q000648:ultrastructure; D066298:In Vitro Techniques; D008297:Male; D008875:Middle Aged; D017006:Rotator Cuff / Q000601:surgery; D000070636:Rotator Cuff Injuries; D012756:Sheep; D013045:Species Specificity; D013314:Stress, Mechanical; D053441:Suture Anchors; D055114:X-Ray Microtomography