title: Pullout strength of suture anchors in comparison with transosseous sutures for rotator cuff repair.
abstract: Suture anchors are increasingly gaining importance in rotator cuff surgery. This means they will be gradually replacing transosseous sutures. The purpose of this study was to compare the stability of transosseous sutures with different suture anchors with regard to their pullout strength depending on bone density. By means of bone densitometry (CT scans), two groups of human humeral head specimens were determined: a healthy and a osteopenic bone group. Following anchor systems were being tested: SPIRALOK 5.0 mm (resorbable, DePuy Mitek), Super Revo 5 mm (titanium, Linvatec), UltraSorb (resorbable, Linvatec) and the double U-sutures with Orthocord USP 2 (partly resorbable, DePuy Mitek) and Ethibond Excel 2 (non-resorbable, Ethicon). The suture anchors/double U-sutures were inserted in the greater tuberosity 12 times. An electromechanical testing machine was used for cyclic loading with power increasing in stages. We recorded the ultimate failure loads, the system displacements and the modes of failure. The suture anchors tended to bring about higher ultimate failure loads than the transosseous double U-sutures. This difference was significant in the comparison of the Ethibond suture and the SPIRALOK 5.0 mm-both in healthy and osteopenic bone. Both the suture materials and the SPIRALOK 5.0 mm showed a significant difference in pullout strength on either healthy or osteopenic bone; the titanium anchor SuperRevo 5 mm and the tilting anchor UltraSorb did not show any significant difference in healthy or osteopenic bone. There was no significant difference concerning system displacement (healthy and osteopenic bone) between the five anchor systems tested. The pullout strength of transosseous sutures is neither on healthy nor on osteopenic bone higher than that of suture anchors. Therefore, even osteopenic bone does not constitute a valid reason for the surgeon to perform open surgery by means of transosseous sutures. The choice of sutures in osteopenic bone is of little consequence anyway since it is mostly the bone itself which is the limiting factor.
authors.affiliation: Department of Orthopedics, Klinikum Grosshadern, Ludwig-Maximilians-Universität Munich, Marchioninistr. 15, 81377 Munich, Germany.
authors.forename: Matthias F
authors.initials: MF
authors.lastname: Pietschmann
authors.forename: Valerie
authors.initials: V
authors.lastname: Fröhlich
authors.forename: Andreas
authors.initials: A
authors.lastname: Ficklscherer
authors.forename: Jörg
authors.initials: J
authors.lastname: Hausdorf
authors.forename: Sandra
authors.initials: S
authors.lastname: Utzschneider
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; D002102:Cadaver; D004867:Equipment Design; D005260:Female; D006801:Humans; D006811:Humerus / Q000503:physiopathology / Q000601:surgery; D008297:Male; D008422:Materials Testing; D008875:Middle Aged; D010024:Osteoporosis / Q000503:physiopathology; D017006:Rotator Cuff / Q000601:surgery*; D000070636:Rotator Cuff Injuries; D013314:Stress, Mechanical; D053441:Suture Anchors; D013537:Sutures