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

Medicina ◽  
2021 ◽  
Vol 57 (9) ◽  
pp. 899
Author(s):  
An Sermon ◽  
Ladina Hofmann-Fliri ◽  
Ivan Zderic ◽  
Yash Agarwal ◽  
Simon Scherrer ◽  
...  
Keyword(s):  
Femoral Head ◽  
Failure Load ◽  
Femoral Fractures ◽  
Head Rotation ◽  
Cement Augmentation ◽  
Fixation Strength ◽  
Fixation Stability ◽  
Head Element ◽  
Increasing Cyclic Loading ◽  
The Impact

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.

scholarly journals Anchorage strategies in geriatric hip fracture management

2016 ◽  
Vol 1 (2) ◽  
pp. 73-78
Author(s):  
Matthias Knobe ◽  
Hans-Christoph Pape
Keyword(s):  
Hip Fracture ◽  
Femoral Head ◽  
Femoral Neck ◽  
Bone Quality ◽  
Femoral Fractures ◽  
Cement Augmentation ◽  
Femoral Neck Fractures ◽  
Patient Specific ◽  
Mechanical Complication ◽  
Augmentation Strategies

AbstractThere is an enormous humanitarian and socioeconomic need to improve the quality and effectiveness of care for patients with hip fracture. To reduce mechanical complications in the osteosynthesis of proximal femoral fractures, improved fixation techniques have been developed including blade or screw-anchor devices, locked minimally invasive or cement augmentation strategies. However, despite numerous innovations and advances regarding implant design and surgical techniques, systemic and mechanical complication rates remain high. Treatment success depends on secure implant fixation in often-osteoporotic bone as well as on patient-specific factors (fracture stability, bone quality, comorbidity, and gender) and surgeon-related factors (experience, correct reduction, and optimal screw placement in the head/neck fragment). For fracture fixation, the anchorage of the lag screw within the femoral head plays a crucial role depending on the implant’s design. Meta-analyses and randomized controlled studies demonstrate that there is a strong trend towards arthroplasty treating geriatric femoral neck fractures. However, for young adults as well as older patients with less compromised bone quality, or in undisplaced fractures, head-preserving therapy is preferred as it is less invasive and associated with good functional results. This review summarizes the evidence for the internal fixation of femoral neck fractures and trochanteric femoral fractures in elderly patients. In addition, biomechanical considerations regarding implant anchorage in the femoral head including rotation, migration, and femoral neck shortening are made. Finally, cement augmentation strategies for hip fracture implants are evaluated critically.

Necrosis avascular

2020 ◽  
Vol 63 (2) ◽  
pp. 18-23
Author(s):  
Alejandro Jardón Gómez ◽  
Ana Cristina King ◽  
Carlos Pacheco Díaz
Keyword(s):  
Femoral Head ◽  
Avascular Necrosis ◽  
Femoral Fracture ◽  
Open Fracture ◽  
Clinical Presentation ◽  
Femoral Fractures ◽  
Proximal Femoral Fracture ◽  
Young Population ◽  
Steroid Use

The clinical presentation of a proximal femoral fracture is completely different between young and adult patients. Unlike closed proximal femoral fractures, the incidence of exposed fractures is found in the young population between 15 and 30 years of age. Osteonecrosis of the femoral head is one the complications we can find in this type of fractures. Avascular necrosis (AVN or osteonecrosis) is defined as the interruption of blood supply to the femoral head due to trauma, infectionalcohol or steroid use, resulting in bone necrosis, joint collapse and osteoarthrosis. The treatment will depend on the clinical presentation, age of the patient and when the diagnosis is made. This is a case report of a 16-year-old patient with a gunshot wound on the hip. Surgical cleansing and closed reduction plus internal fixation with a nail in the center of the spine were performed. A 3-year clinical and radiographic follow up was made, observing the evolution of the fracture and the subsequent avascular necrosis that the patient presented. Key words: Proximal femoral fracture; hip; avascular necrosis (AVN, osteonecrosis); open fracture; osteoarthritis.

The association between femoral neck shaft angle and degenerative disease of the hip in a cadaveric model

2021 ◽  
pp. 112070002110130
Author(s):  
Leigh-Anne Tu ◽  
Douglas S Weinberg ◽  
Raymond W Liu
Keyword(s):  
Femoral Head ◽  
Femoral Neck ◽  
Hip Osteoarthritis ◽  
Volume Ratio ◽  
Femoral Head Coverage ◽  
Neck Shaft Angle ◽  
Hip Arthritis ◽  
Femoral Version ◽  
Shaft Angle ◽  
The Impact

Background: While the influences of acetabular dysplasia and overcoverage on hip arthritis have been studied, the impact of femoral neck-shaft angle on hip arthritis is much more poorly understood. The purpose of this study is to determine if a relationship exists between neck shaft angle and the development of osteoarthritis, a better understanding of which would be useful to surgeons planning osteotomies about the hip. Methods: 533 cadaveric femora and acetabulae (1066 total) from the Hamann-Todd Osteological Collection (Cleveland, OH) were acquired. We measured true neck shaft angle using an AP photograph with the femoral neck parallel to the table. Femoral head volume to acetabular volume ratio, representing femoral head coverage, as well as femoral version were utilised. Correlation between neck shaft angle, femoral version, femoral head coverage and osteoarthritis were evaluated with multiple regression analysis. Results: The mean age and standard deviation was 56 ± 10 years. There were 64 females (12%) and 469 males. There were 380 Caucasians (71%) and 153 African-Americans. Mean femoral version was 11° ± 12° and mean true neck shaft angle was 127.7° ± 5.9° There was a strong correlation between age and arthritis (standardised beta 0.488, p < 0.001). There was a significant correlation between increasing true neck shaft angle and decreasing hip arthritis (standardised beta -0.024, p = 0.038). In the femoral head overcoverage subset, increasing true neck shaft angle was still significantly associated with decreasing hip arthritis (standardised beta −0.088, p = 0.018), although this relationship was not significant with femoral head undercoverage subset. Conclusions: With sufficient acetabular coverage, a relative increase in femoral neck shaft angle within the physiologic range is associated with decreased hip osteoarthritis. Clinical relevance: An understanding of the relationship between femoral neck shaft angle and hip osteoarthritis could be useful for surgeons planning pelvic or proximal femur osteotomies in children.

scholarly journals Dynamic plate osteosynthesis for fracture stabilization: how to do it

2010 ◽  
Vol 2 (1) ◽  
pp. 4 ◽  
Author(s):  
Juerg Sonderegger ◽  
Karl R. Grob ◽  
Markus S. Kuster
Keyword(s):  
Plate Osteosynthesis ◽  
Plate Fixation ◽  
Femoral Fractures ◽  
Fracture Site ◽  
Fixation Strength ◽  
Safe Procedure ◽  
Font Size ◽  
Biological Fixation ◽  
Fracture Stabilization ◽  
Anterior Knee

<!--StartFragment--> <p class="MsoNormal"><span style="font-family: 'Times New Roman', Arial, Helvetica, sans-serif; font-size: medium;"><span style="font-size: 16px;"><span style="font-family: Verdana, Arial, Helvetica, sans-serif; font-size: x-small;"><span style="font-size: 10px;"><p class="MsoNormal">Plate osteosynthesis is one treatment option for the stabilization of long bones. It is widely accepted to achieve bone healing with a dynamic and biological fixation where the perfusion of the bone is left intact and micromotion at the fracture gap is allowed. The indications for a dynamic plate osteosynthesis include distal tibial and femoral fractures, some midshaft fractures, and adolescent tibial and femoral fractures with not fully closed growth plates. Although many lower limb shaft fractures are managed successfully with intramedullary nails, there are some important advantages of open-reduction-and-plate fixation: the risk of malalignment, anterior knee pain, or nonunion seems to be lower. The surgeon performing a plate osteosynthesis has the possibility to influence fixation strength and micromotion at the fracture gap. Long plates and oblique screws at the plate ends increase fixation strength. However, the number of screws does influence stiffness and stability. Lag screws and screws close to the fracture site reduce micromotion dramatically. </p><p class="MsoNormal">Dynamic plate osteosynthesis can be achieved by applying some simple rules: long plates with only a few screws should be used. Oblique screws at the plate ends increase the pullout strength. Two or three holes at the fracture site should be omitted. Lag screws, especially through the plate, must be avoided whenever possible. Compression is not required. Locking plates are recommended only in fractures close to the joint. When respecting these basic concepts, dynamic plate osteosynthesis is a safe procedure with a high healing and a low complication rate. </p></span></span></span></span></p>

scholarly journals The Mental Capacity Act 2005: review of mental capacity assessment in people with proximal femoral fracture

2010 ◽  
Vol 34 (7) ◽  
pp. 284-286 ◽  
Author(s):  
P. Guyver ◽  
P. Hindle ◽  
J. Harrison ◽  
N. Jain ◽  
M. Brinsden
Keyword(s):  
Staff Training ◽  
Femoral Fractures ◽  
Proximal Femoral Fracture ◽  
Mental Capacity ◽  
Clinical Implications ◽  
Proximal Femoral Fractures ◽  
Mental Capacity Act 2005 ◽  
Consent To Treatment ◽  
Mental Capacity Act ◽  
The Impact

Aims and methodTo ascertain whether patients with proximal femoral fractures were being correctly assessed in line with the Mental Capacity Act 2005. Fifty people admitted with proximal femoral fractures were audited to assess whether they had given consent to treatment in accordance with the Act. A Mental Capacity Act 2005 guidance and assessment form was then introduced accompanied by staff training. A re-audit was undertaken to assess the impact.ResultsThe initial audit showed that only one person (2%) had been properly assessed. The re-audit demonstrated that the use of the Mental Capacity Act 2005 assessment form ensured correct assessment.Clinical implicationsOur findings suggest the form is a useful tool in the documentation and assessment of an individual's capacity under the Mental Capacity Act.

A Measurement Method of Tensile Strength for Irregular Small Stones

2014 ◽  
Vol 507 ◽  
pp. 281-285 ◽  
Author(s):  
Jin He Gao ◽  
Shou Long Zhang ◽  
Yan Bin Huang
Keyword(s):  
Tensile Strength ◽  
Failure Load ◽  
Round Hole ◽  
Mechanics Model ◽  
Measuring Devices ◽  
Loading Method ◽  
Distribution Rule ◽  
Small Stone ◽  
Porous Strip ◽  
The Impact

This article studied the drilling loading method for the tensile strength of irregular small-stone, designed the measuring devices, and addressed the measurement problems of irregular small-stone tensile strength. Based on static equilibrium theory, it analyzed the distribution rule of tensile stress in dangerous section, and established the mechanics model of drilling loading method. In considering the impact rules of characteristic destruction size and round-hole size on the hole-edge stress concentration, on this basis it established the theoretical formulas of measuring the tensile strength of brittle materials. It practically measured the failure load of small drilling bluestone, introduced the failure load into the theoretical measurement formula of brittle material tensile strength, and then obtained the tensile strength of stones, while it measured the tensile strength of non-porous strip specimen. The tensile strength of irregular stones measured by the drilling loading method is basically consistent with the tensile strength obtained from the tensile test of non-porous strip specimen, and therefore the drilling loading method is able to reasonably measure the tensile strength of small stones.

scholarly journals Comparison of the Sliding and Femoral Head Rotation among Three Different Femoral Head Fixation Devices for Trochanteric Fractures

2015 ◽  
Vol 7 (3) ◽  
pp. 291 ◽  
Author(s):  
Nobuaki Chinzei ◽  
Takafumi Hiranaka ◽  
Takahiro Niikura ◽  
Mitsuo Tsuji ◽  
Ryosuke Kuroda ◽  
...  
Keyword(s):  
Femoral Head ◽  
Head Rotation ◽  
Trochanteric Fractures ◽  
Head Fixation ◽  
Fixation Devices

A BIOMECHANICAL VALIDATION OF A NEW FEMORAL NECK FIXATION DYNAMIC HIP SCREW FOR PROXIMAL FEMORAL FRACTURE

2010 ◽  
Vol 22 (01) ◽  
pp. 53-59 ◽  
Author(s):  
Shih-Wei Lin ◽  
Jaw-Lin Wang
Keyword(s):  
Femoral Neck ◽  
Mechanical Test ◽  
Femoral Fractures ◽  
Vertical Displacement ◽  
Proximal Femoral Fracture ◽  
Dynamic Hip Screw ◽  
Fixation Strength ◽  
Proximal Femoral Fractures ◽  
Suitable Site ◽  
Hip Screw

High failure rates are expected in the treatment of osteoporotic proximal femoral fractures. A newly designed femoral neck locking dynamic hip screw has been developed to increase the fixation strength; a biomechanical examination was performed to prove its efficacy. Femoral surrogate specimens were used for the test. Unstable intertrochanteric fractures were created on specimens. Then these specimens were divided into two groups to test two different methods of fixation: (1) the conventional dynamic hip screw and (2) the new designed femoral neck fixation dynamic hip screw. For each specimen, the peak cyclic loading was 800 N, and a total of 20,000 cycles were applied. The vertical displacement, rotation around the long axis of lag screw, and the varus rotation around the center of femoral head between the two groups were compared at specific intervals. All the conventional dynamic hip screw constructs failed within 1000 cycles, while no gross mechanical failure was recorded for the femoral neck fixation dynamic hip construct even after 20,000 loading cycles. The mechanical test comparing the two constructs at the end of each 1000 loading cycles demonstrated that the femoral neck fixation dynamic hip screw construct is stronger than that of the conventional dynamic hip screw. For the fixation of proximal femoral fractures, the femoral neck fixation dynamic hip screw can provide a stronger support than what a conventional dynamic hip screw can do. At the same time, femoral neck can be a suitable site for the application of proximal locking screws.

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