Is bone-cement augmentation of screw-anchor fixation systems superior in unstable femoral neck fractures? A biomechanical cadaveric study

Knobe, Matthias; Bettag, Sebastian; Kammerlander, Christian; Altgassen, Simon; Maier, Klaus-Jürgen; Nebelung, Sven; Prescher, Andreas; Horst, Klemens; Pishnamaz, Miguel; Herren, Christian; Mundt, Marion; Stoffel, Marcus; Markert, Bernd; Gueorguiev, Boyko

doi:10.1016/j.injury.2018.10.038

Cited by 11 publications

(6 citation statements)

References 39 publications

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“…The findings of the current study are in agreement with previous clinical and biomechanical reports demonstrating the beneficial effect of cement augmentation on implant-to-bone anchorage by increased cut-out resistance [ 16 , 19 , 24 , 25 , 26 , 27 ]. In contrast, an investigation on the overall biomechanical performance of a screw-and-blade anchor implant system in a human cadaveric model with a simulated unstable femoral neck fracture concluded that cement augmentation results in no additional advantages [ 28 ]. Comparable biomechanical competence of the same screw-and-blade anchor implant system versus a helical blade and superiority versus a cephalic screw, all without cement augmentation, was reported in another study [ 29 ].…”

Section: Discussionmentioning

confidence: 99%

Impact of Bone Cement Augmentation on the Fixation Strength of TFNA Blades and Screws

Sermon

Hofmann‐Fliri

Agarwal³

et al. 2021

Medicina

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Background and Objectives: Hip fractures constitute the most debilitating complication of osteoporosis with steadily increasing incidences in the aging population. Their intramedullary nailing can be challenging because of poor anchorage in the osteoporotic femoral head. Cement augmentation of Proximal Femoral Nail Antirotation (PFNA) blades demonstrated promising results by enhancing cut-out resistance in proximal femoral fractures. The aim of this study was to assess the impact of augmentation on the fixation strength of TFN-ADVANCEDTM Proximal Femoral Nailing System (TFNA) blades and screws within the femoral head and compare its effect when they are implanted in centre or anteroposterior off-centre position. Materials and Methods: Eight groups were formed out of 96 polyurethane low-density foam specimens simulating isolated femoral heads with poor bone quality. The specimens in each group were implanted with either non-augmented or cement-augmented TFNA blades or screws in centre or anteroposterior off-centre positions, 7 mm anterior or posterior. Mechanical testing was performed under progressively increasing cyclic loading until failure, in setup simulating an unstable pertrochanteric fracture with a lack of posteromedial support and load sharing at the fracture gap. Varus-valgus and head rotation angles were monitored. A varus collapse of 5° or 10° head rotation was defined as a clinically relevant failure. Results: Failure load (N) for specimens with augmented TFNA head elements (screw/blade centre: 3799 ± 326/3228 ± 478; screw/blade off-centre: 2680 ± 182/2591 ± 244) was significantly higher compared with respective non-augmented specimens (screw/blade centre: 1593 ± 120/1489 ± 41; screw/blade off-centre: 515 ± 73/1018 ± 48), p < 0.001. For both non-augmented and augmented specimens failure load in the centre position was significantly higher compared with the respective off-centre positions, regardless of the head element type, p < 0.001. Augmented off-centre TFNA head elements had significantly higher failure load compared with non-augmented centrally placed implants, p < 0.001. Conclusions: Cement augmentation clearly enhances the fixation stability of TFNA blades and screws. Non-augmented blades outperformed screws in the anteroposterior off-centre position. Positioning of TFNA blades in the femoral head is more forgiving than TFNA screws in terms of failure load.

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Section: Discussionmentioning

confidence: 99%

Impact of Bone Cement Augmentation on the Fixation Strength of TFNA Blades and Screws

Sermon

Hofmann‐Fliri

Agarwal³

et al. 2021

Medicina

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“…According to previous studies testing centrally inserted RoSA implants in complete femur specimens, fracture collapse with additional femoral neck fracture [11] , varus collapse [36] and cutout [ 8 , 11 ] were observed as modes of failure. Varus collapse with additional femoral neck fracture seems to be a typical failure mechanism for vertically aligned implants, as well as for such intramedullary systems as the TRIGEN INTERTAN Intertrochanteric Antegrade Nail (Smith and Nephew Inc, Andover, MA, USA) [37] .…”

Section: Article In Pressmentioning

confidence: 99%

Screw-blade fixation systems for implant anchorage in the femoral head: Horizontal blade orientation provides superior stability

Schopper

Keck

Migliorini

et al. 2021

Injury

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Objectives: Despite continual improvement in the methods and devices used for treatment of proximal femoral fractures, unacceptably high failure rates remain. Novel screw-blade implant systems, combining a lag screw with a blade -the latter adding rotational stability to the femoral head -offer improvement of osseous purchase, especially in osteoporotic bone. The aim of this study was to compare biomechanically the head element (HE) anchorage of two screw-blade implant systems differing in blade orientation in the femoral head -vertical versus horizontal.Methods: Twenty paired human cadaveric femoral heads were assigned to four groups ( n = 10), implanted with either Rotationally Stable Screw-Anchor HE (RoSA-HE, vertical blade orientation) or Gamma3 Rotation Control Lag Screw (Gamma-RC, horizontal blade orientation) in center or off-center position, and biomechanically tested until failure under progressively increasing cyclic loading at 2 Hz.Results: Cycles to failure and failure load were significantly higher for Gamma-RC versus RoSA-HE in center position and not significantly different between them in off-center position, p = 0.03 and p = 0.22, respectively. In center position, the progression of both rotation around implant axis and varus deformation over time demonstrated superiority of the implant with horizontal versus vertical blade orientation. Compared with center positioning, off-center implant placement led to a significant decrease in stiffness, cycles to failure and failure load for Gamma-RC, but not for RoSA-HE, p < 0.01 and p = 0.99, respectively. Conclusion:Horizontal blade orientation of screw-blade implant systems demonstrates better anchorage in the femoral head versus vertical blade orientation in center position. As the stability of the implant system with horizontal blade orientation drops sharply in off-center position, central insertion is its placement of choice.

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“…The ability of the internal fixation device to provide good stability becomes a key factor in maintaining fracture reduction and stabilization. Pauwels type III FNFs are considered more unstable due to the high shear stress of these fractures, so it is required that implants used for fixation of Pauwels type III FNFs should provide optimal mechanical resistance [ 10 , 11 ]. Internal fixation with traditional multiple cannulated screws or sliding hip screws are the methods preferred by most surgeons [ 12 ].…”

Section: Introductionmentioning

confidence: 99%

Biomechanical comparison of the femoral neck system versus InterTan nail and three cannulated screws for unstable Pauwels type III femoral neck fracture

et al. 2022

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Background There are a variety of internal fixation methods for unstable femoral neck fractures (FNFs), but the best method is still unclear. Femoral neck system (FNS) is a dynamic angular stabilization system with cross screws, and is a new internal fixation implant designed for minimally invasive fixation of FNFs. In this study, we conducted a biomechanical comparison of FNS, InterTan nail and three cannulated screws for the treatment of Pauwels III FNFs and investigate the biomechanical properties of FNS. Methods A total of 18 left artificial femurs were selected and randomly divide into Group A (fixation with FNS), Group B (fixation with InterTan nail) and Group C (fixation with three cannulated screws), with 6 specimens in each group. After creating Pauwels type III FNF models, the specimens in each were tested with non-destructive quasi-static tests, including torsion, A-P bending and axial compression tests. The average slope of the linear load–deformation curve obtained from quasi-static tests defines the initial torsional stiffness, A-P bending stiffness, and axial compression stiffness. After cyclic loading test was applied, the overall deformation of models and local deformation of implant holes in each group were assessed. The overall deformation was estimated as the displacement recorded by the software of the mechanical testing apparatus. Local deformation was defined as interfragmental displacement. Data were analyzed by one-way analysis of variance (ANOVA) followed by Bonferroni post hoc test using the SPSS software (version 24.0, IBM, New York, NY, USA). Correlation analysis was performed using Pearson’s correlation analysis. Results Group B exhibited significantly higher axial stiffness and A-P bending stiffness than the other two groups (P < 0.01), while Group A had significantly higher axial stiffness and A-P bending stiffness than Group C (P < 0.01). Groups A and B exhibited significantly higher torsional stiffness than Group C (P < 0.01), no statistical significance was observed between Groups A and B (P > 0.05). Group B exhibited significantly lower overall and local deformations than the other two groups (P < 0.01), while Group A had significantly lower overall and local deformations than Group C (P < 0.01). Correlation analysis revealed positive correlation between axial stiffness and A-P bending stiffness (r = 0.925, P < 0.01), torsional stiffness (r = 0.727, P < 0.01), between torsional stiffness and A-P bending stiffness; negative correlation between overall, local deformations and axial stiffness (r = − 0.889, − 0.901, respectively, both P < 0.01), and positive correlation between the two deformations (r = − 0.978, P < 0.01). Conclusion For fixation of unstable FNFs, InterTan nail showed the highest axial stiffness and A-P bending stiffness, followed by FNS, and then three cannulated screws. Torsional stiffness of FNS was comparable to that of the InterTan nail. FNS, as a novel minimally invasive implant, can create good mechanical environment for the healing of unstable FNFs. Clinical studies are needed to confirm the potential advantages of FNS observed in this biomechanical study.

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Is bone-cement augmentation of screw-anchor fixation systems superior in unstable femoral neck fractures? A biomechanical cadaveric study

Cited by 11 publications

References 39 publications

Impact of Bone Cement Augmentation on the Fixation Strength of TFNA Blades and Screws

Impact of Bone Cement Augmentation on the Fixation Strength of TFNA Blades and Screws

Screw-blade fixation systems for implant anchorage in the femoral head: Horizontal blade orientation provides superior stability

Biomechanical comparison of the femoral neck system versus InterTan nail and three cannulated screws for unstable Pauwels type III femoral neck fracture

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