Does an additional antirotation U-Blade (RC) lag screw improve treatment of AO/OTA 31 A1-3 fractures with gamma 3 nail?
BACKGROUND
Poor bone quality and unstable fractures increase the cut-out rate in implants with gliding lag screws. The U-Blade (RC) lag screw for the Gamma3®nail was introduced to provide monoaxial rotational stability of the femoral head and neck fragment. The purpose of this study was to evaluate whether the use of the U-Blade (RC) lag screw is associated with reduced cut-out in patients with OTA/AO 31A1-3 fractures.


METHODS
Between 2009 and 2014, 751 patients with OTA/AO 31A1-3 fractures were treated with a Gamma3®nail at our institution. Out of this sample 199 patients were treated with U-blade (RC) lag screws. A total of 135 patients (117 female, 18 male) with standard lag screw (treatment group A) were matched equally regarding age (±4 years) sex, fracture type and location to 135 patients with U-blade (RC) lag screw (treatment group B). Within a mean follow up of 9.2 months (range 6-18 months) we assessed the cut-out rate, the calTAD, lag screw migration, the Parker's mobility score and the Parker's ratio at postoperatively, six and 12 months following surgery. Furthermore we recorded all complications, ASA-Score, hospital stay and duration of surgery retrospectively.


RESULTS
The most common fracture among group B with a cut-out of the lag screw were AO/OTA 2.3 and 3.2 fractures whereas in group A cut-out was most commonly seen in AO/OTA 2.1, 2.2 and 2.3 fractures, there was no significant reduction of the cut-out rate in group B 2.2% (n=3) compared to group A 3.7% (n=5). The duration of surgery was significantly shorter in group A (p<0.05). There was no significant difference in lag screw placement, the Parker's ratio and mobilization.


CONCLUSIONS
In our study the U-Blade (RC) lag screw did not reduce the cut-out in treatment of OTA/AO 31A1-3 fractures at all. Considering the longer duration of surgery and the higher costs of the U-Blade (RC) lag screw, our results do not justify its use. However, further prospective randomized studies will be necessary.
Department of Trauma Surgery, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria. Electronic address: nikolaus.lang@meduniwien.ac.at.
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Lang
Department of Trauma Surgery, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria. Electronic address: catrhin.arthold@meduniwien.ac.at.
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Arthold
Department of Trauma Surgery, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria. Electronic address: julian.joestl@meduniwien.ac.at.
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Joestl
Department of Trauma Surgery, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria. Electronic address: anna.gormasz@meduniwien.ac.at.
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Gormasz
Department of Trauma Surgery, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria. Electronic address: sandra.boesmueller@meduniwien.ac.at.
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Boesmueller
Department of Trauma Surgery, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria.
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Hajdu
Department of Trauma Surgery, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria. Electronic address: kambiz.sarahrudi@meduniwien.ac.at.
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Sarahrudi
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001858:Bone Nails; D001863:Bone Screws; D005260:Female; D005264:Femoral Fractures / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D005272:Femur Neck / Q000000981:diagnostic imaging / Q000473:pathology*; D005594:Fracture Fixation, Intramedullary; D006620:Hip Fractures / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011475:Prosthesis Failure; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome
AO/OTA 31.A1-3 femur fractures; Cut-out; Gamma3 nail; U-Blade (RC) lag screw