title: Is there an increased stem migration or compromised osteointegration of the Mayo short-stemmed prosthesis following cerclage wiring of an intrasurgical periprosthetic fracture?
abstract: OBJECTIVE
  Short-stemmed prostheses are increasingly regarded as implants of first choice in primary THA. As a result of the press-fit fixation in the femoral metaphysis, the occurrence of intraoperative fractures were reported. The aim of this study was to analyze the postoperative results of the Mayo short-stem prosthesis following treatment of an intrasurgical femur fracture with cerclage wiring.
  
  
  METHODS
  From 1999 to 2005, in 38 patients (18 females, 20 males; mean age 56 years; mean BMI = 27) with the diagnosis of coxarthrosis in whom a Mayo short-stemmed prosthesis has been implanted, an intraoperative fracture was observed. The fractures were treated with cerclage wiring (1 cerclage, n = 32; 2 cerclages, n = 5; 3 cerclages, n = 1). Postoperatively, all patients were prescribed mobilization without weight-bearing (floor contact) on the treated leg for 6 weeks. Using the Wristing software, longitudinal stem migration and varus-valgus femoral stem alignment were examined digitally in anteroposterior X-rays taken immediately after surgery, after 6 weeks and on average after 5.7 years (Zeh et al., Z Orthop Unfall 149:200-205, 2011). Additionally, the incidence of periprosthetic radiolucent lines was captured in the anteroposterior X-rays and assigned to the Gruen zones. Additionally, a DEXA scan was performed. The X-rays of a matched control group after the implantation of a Mayo prosthesis without femur fracture were analyzed by the same method.
  
  
  RESULTS
  There was no significant migration of the Mayo prosthesis in the study or control groups during postoperative follow-up (t test, P > 0.05). The cerclage group compared with the control group showed a statistically significant valgus tilt of 1.5° on average during the follow-up, which is regarded to be clinically not relevant. The frequency of occurrence of radiolucent lines was not statistically different (chi-square test, χ = 0.42, P = 0.51). DEXA scans showed no differences of the bone mineral density in the Gruen zones compared with a historical control group.
  
  
  CONCLUSIONS
  After wiring of an intrasurgical fracture, no disadvantage could be proven for Mayo prosthesis regarding stem migration and varus-valgus alignment. Furthermore, due to the absence of differences in the occurrence of radiolucent lines and the same results in the DEXA scan, an unimpaired osseointegration is assumed.
authors.affiliation: Department of Orthopaedics and Traumatology, Faculty of Medicine, Martin-Luther-University of Halle-Wittenberg, Magdeburger Str. 22, 06097 Halle/Saale, Germany. alexander.zeh@medizin.uni-halle.de
authors.forename: Alexander
authors.initials: A
authors.lastname: Zeh
authors.forename: Florian
authors.initials: F
authors.lastname: Radetzki
authors.forename: Verena
authors.initials: V
authors.lastname: Diers
authors.forename: Dirk
authors.initials: D
authors.lastname: Bach
authors.forename: Marc
authors.initials: M
authors.lastname: Röllinghoff
authors.forename: Karl Stefan
authors.initials: KS
authors.lastname: Delank
mesh_terms: D001864:Bone Wires; D005260:Female; D006620:Hip Fractures / Q000601:surgery*; D006622:Hip Prosthesis; D006801:Humans; D007431:Intraoperative Complications / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D016348:Osseointegration; D057068:Periprosthetic Fractures / Q000601:surgery*; D011474:Prosthesis Design; D011475:Prosthesis Failure; D016896:Treatment Outcome