title: In vivo failure analysis of intramedullary cement restrictors in 100 hip arthroplasties.
abstract: BACKGROUND
  We occasionally noticed excessive distal plug position in our clinical routine of cemented hip arthroplasties. We therefore performed an analysis of risk factors for migration of a biodegradable intramedullary gelatine plug.
  
  
  METHODS
  The performance of a cement restrictor was studied in 100 consecutive cemented total hip arthroplasties implanted with third-generation cementing techniques. In a radiographic analysis anatomical parameters, cement mantle quality, and mechanisms and factors for restrictor failure were evaluated.
  
  
  RESULTS
  40 restrictors showed inadequate performance: 5 cases of tilting, 22 cement leakages, 16 excessive migrations, 2 excessive migrations plus leakages, and 1 case of leakage plus tilting. excessive migration (< 5 cm) was more common in large intramedullary canals (p = 0.04) and cement leakage was more common in patients with a proximally located isthmus (p = 0.04). Half of the hips showed a complete or almost complete filling of the intramedullary cavity, which was more often found in operations carried out by experienced surgeons.
  
  
  CONCLUSIONS
  A more reliable plug design should be considered for patients with wide intramedullary canals and a high isthmus, to minimize the risk of plug migration and poor cement mantle quality.
authors.affiliation: Department of Orthopaedics, University of Heidelberg, Germany.
authors.forename: Rudi Georg
authors.initials: RG
authors.lastname: Bitsch
authors.forename: Steffen Joachim
authors.initials: SJ
authors.lastname: Breusch
authors.forename: Marc
authors.initials: M
authors.lastname: Thomsen
authors.forename: Sven
authors.initials: S
authors.lastname: Schneider
authors.forename: Christian
authors.initials: C
authors.lastname: Heisel
mesh_terms: D020341:Absorbable Implants; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods; D001843:Bone Cements; D002484:Cementation; D005780:Gelatin; D006801:Humans; D008422:Materials Testing; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012307:Risk Factors
chemical_list: D001843:Bone Cements; D005780:Gelatin