title: Stainless steel wire versus FiberWire suture cerclage fixation to stabilize the humerus in total shoulder arthroplasty.
abstract: OBJECTIVE
  No. 5 FiberWire (Arthrex, Naples, FL, USA) cerclage (FWC) and 1.25-mm stainless steel wire cerclage (SSWC) are biomechanically similar in resistance to prosthetic subsidence in shoulder arthroplasty.
  
  
  METHODS
  In this laboratory bench study, 3 different surgical knot configurations (4-throw knot, cow hitch, and simple hitch) using a No. 5 FWC were evaluated and compared with a 1.25-mm SSWC. First, distraction tests were performed using bovine femoral cortical half shells mounted on a testing jig. Cerclage tightening, load to a 3-mm gap opening, and load to total failure were measured. Second, uncemented humeral prosthetic stems were inserted into an experimentally split humeral medullary canal, secured by the cerclage. After 100 N of preloading, the prosthesis was advanced into the humerus at a speed of 0.2 mm/s, and resistance during subsidence up to a penetration depth of 10 mm, as well as gap opening, was measured.
  
  
  RESULTS
  Tightening force showed higher values for SSWC (618 N) than FWC (131-137 N) (P < .001). Load to total failure was comparable among the 3 different FWC knots (2,642-2,804 N), which were significantly stronger than SSWC (1,775 N, P < .001). At 3 mm of distraction, SSWC (1,820 N), cow hitch (1,803 N), and single-throw hitch (1,709 N) performed significantly better than a 4-throw knot (1,289 N) (P < .01). Subsidence testing showed no difference in force restraint or gap opening between the best FWC and SSWC.
  
  
  CONCLUSIONS
  FWCs appear, in vitro, equally suitable to steel wires to stabilize nondisplaced periprosthetic humeral fractures. To actively reduce a displaced fracture, steel wires may still be the first choice.
authors.affiliation: Department of Orthopaedics, University of Zürich, Balgrist University Hospital, Zürich, Switzerland. Electronic address: niklas.renner@balgrist.ch.
authors.forename: Niklas
authors.initials: N
authors.lastname: Renner
authors.affiliation: Department of Orthopaedics, University of Zürich, Balgrist University Hospital, Zürich, Switzerland.
authors.forename: Karl
authors.initials: K
authors.lastname: Wieser
authors.affiliation: Department of Ortrhopaedics, Private Hospital Maria Hilf, Klagenfurt, Austria.
authors.forename: Georg
authors.initials: G
authors.lastname: Lajtai
authors.affiliation: Department of Orthopaedics, University of Zürich, Balgrist University Hospital, Zürich, Switzerland.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Morrey
authors.affiliation: Department of Orthopaedics, University of Zürich, Balgrist University Hospital, Zürich, Switzerland.
authors.forename: Dominik C
authors.initials: DC
authors.lastname: Meyer
mesh_terms: D000818:Animals; D019643:Arthroplasty, Replacement / Q000009:adverse effects*; D001672:Biocompatible Materials; D001696:Biomechanical Phenomena; D001864:Bone Wires; D002417:Cattle; D006801:Humans; D006811:Humerus / Q000293:injuries / Q000601:surgery*; D023421:Models, Animal; D057068:Periprosthetic Fractures / Q000209:etiology / Q000601:surgery*; D013193:Stainless Steel; D013536:Suture Techniques; D013537:Sutures
chemical_list: D001672:Biocompatible Materials; D013193:Stainless Steel
keywords: Cerclage; periprosthetic humeral fracture; total shoulder arthroplasty