title: Prevention of hip lag screw cut-out by cement augmentation: description of a new technique and preliminary clinical results.
abstract: Cement augmentation of hip lag screws to avoid cut-out displacement is classically described, along with a number of technical drawbacks. In a series of six elderly patients with hip fractures in osteoporotic bone, we illustrate catheter-assisted delivery of limited amounts of a new bisphenol-a-glycidyl dimethacrylate (bis-GMA)-based composite into hip compression screw threads, enabling significant increase in insertional torque compared with unaugmented screws. In two patients, unaugmented screws that did not initially purchase were tightened with a minimum torque of 1 N-m after augmenting with bis-GMA-based composite. No screw or femoral head displacement relative to baseline (2 days postoperative) was seen in any patient on serial x-rays taken up to 6 months after surgery. This technique adds approximately 10 minutes to surgery time. Advantages of bis-GMA-based composite over traditional PMMA augmentation include mixing on-demand, the ability to make repeated injections over extended periods in the event of femoral head perforations (in one patient in this series), precise placement of adequately small volumes of material, and a lower exotherm. Potentially, this bis-GMA-based composite may reduce the frequency of cut-out complications by enhancing bone-implant interface.
authors.affiliation: Centre Hospitalier Molière Longchamp, 21 avenue Coghen, B-1180 Brussels, Belgium. marek.szpalski@win.be
authors.forename: Marek
authors.initials: M
authors.lastname: Szpalski
authors.forename: Pierre-Yves
authors.initials: PY
authors.lastname: Descamps
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Hayez
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Raad
authors.forename: Robert
authors.initials: R
authors.lastname: Gunzburg
authors.forename: Tony S
authors.initials: TS
authors.lastname: Keller
authors.forename: Victor
authors.initials: V
authors.lastname: Kosmopoulos
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017438:Bisphenol A-Glycidyl Methacrylate / Q000627:therapeutic use*; D001843:Bone Cements; D001863:Bone Screws; D005260:Female; D006620:Hip Fractures / Q000000981:diagnostic imaging / Q000601:surgery*; D006801:Humans; D011859:Radiography
chemical_list: D001843:Bone Cements; D017438:Bisphenol A-Glycidyl Methacrylate