scholarly journals Biomechanical analysis of two medial buttress plate fixation methods to treat Pauwels type III femoral neck fractures

2022 ◽  
Vol 23 (1) ◽  
Author(s):  
Jichao Liu ◽  
Zhengwei Li ◽  
Jie Ding ◽  
Bingzhe Huang ◽  
Chengdong Piao
Keyword(s):  
Femoral Neck ◽  
Plate Fixation ◽  
Femoral Neck Fractures ◽  
Biomechanical Analysis ◽  
Axial Stiffness ◽  
Cannulated Screws ◽  
Fracture Fragment ◽  
Fixation Methods ◽  
Type Iii ◽  
Buttress Plate

Abstract Background Femoral neck fractures in young people are usually Pauwels Type III fractures. The common treatment method are multiple parallel cannulated screws or dynamic hip screw sliding compression fixation. Due to the huge shear stress, the rate of complications such as femoral head necrosis and nonunion is still high after treatment. The aim of our study was to compare the stabilities of two fixation methods in fixating pauwels type III femoral neck fractures. Methods All biomimetic fracture samples are fixed with three cannulated screws combined with a medial buttress plate. There were two fixation groups for the buttress plate and proximal fracture fragment: Group A, long screw (40 mm); Group B, short screw (6 mm). Samples were subjected to electrical strain measurement under a load of 500 N, axial stiffness was measured, and then the samples were axially loaded until failure. More than 5 mm of displacement or synthetic bone fracture was considered as construct failure. Results There were no significant differences in failure load (P = 0.669), stiffness (P = 0.842), or strain distribution (P > 0.05) between the two groups. Conclusions Unicortical short screws can provide the same stability as long screws for Pauwels Type III Femoral Neck Fractures.

scholarly journals Pauwels screw combined inverted triangle cannulated screws for the treatment of Pauwels type-III femoral neck fracture:- a new surgical method based on the morphology of the fracture

2020 ◽  
Author(s):  
Gang Xue ◽  
Siting Chen ◽  
Maosheng Zhou ◽  
Zhengyu Wang ◽  
Liangliang Wan ◽  
...  
Keyword(s):  
Femoral Neck ◽  
Femoral Neck Fracture ◽  
Femoral Neck Fractures ◽  
Harris Hip Score ◽  
Cannulated Screws ◽  
Type Iii ◽  
Operative Duration ◽  
Neck Fracture ◽  
Flexion And Extension

Abstract Background: Femoral neck fracture is a serious injury in adults with significant functional consequences.Internal fixtion is an established treatment for femoral neck fractures in young adult patients .However, the risk of complications following fixation has plague orthopedists for decades.In all femoral neck fracture ,Pauwels type-III femoral neck fractures with a large vertical shear force were more likely to cause clinical failure.The aim of this study is to intruduce a new surgical technique for the treatment of this fracture according to the morphology of the fracture using the combination of Pauwels screw and inverted triangle cannulated screws(PSTCS)，and report the clinical effects in a prospective cohort of 14 patients.Methods: From June 2017 to June 2019, a total of 14 patients (8 males and 6 females ) with Pauwels type-III femoral neck fracture underwent the surgical treatment of PSTCS according to the morphologyical types of fracture in clinical operation in our department. Patients were allowed to perform contraction exercises of quadriceps femoris on postoperative day1, passive flexion and extension exercises postoperative day 2 onwards, and active flexion and extension exercises postoperative day 7 onwards. Patients were allowed for partial-weight bearing walking postoperative 1month onwards with axillary crutches. After one month AP and lateral radiograph were taken. Full ambulation was permitted until the presence of radiological consolidation.Intraoperative (Operative duration,Blood loss),postoperation(Fracture union time,The Harris Hip Score,Visual analog score) were record for comparison.Results: All patients were followed up for at least 12 months.In the end point of the follow up ,12 of the 14 patients (85.7%)with pauwels type-III femoral neck fractures had achieved satisfactory hip function. Operative duration was a mean of 49.5 ±10.4 minutes.Intraoperative blood loss was between 26 and 110 ml (mean, 44.4±20.6ml) and without intraoperative blood transfusion . The Harris Hip Score was between 64 and 95(mean,87.6±8.9).Fracture healing was observed in all patients according to the X-ray . No internal fixation was loosened or screw cut-out in the follow-up period.The femoral head necrosis was observed in 1 patient in this study. In addition, there was no obvious fracture displacement, femoral neck shortening, or hip varus. Conclusions: The study showed that PSTCS can provide a satisfactory clinical outcomes for treatment of pauwels type-III femoral neck fractures.Most patients (85.7%) achieved good or excellent results with the use of PSTCS,which appears to be a reliable method and provides another choice for this problematic fracture.The new internal fixation method of PSTCS can provide mechanical stability and promote fracture healing

Stability of femoral neck fracture fixation: A finite element analysis

2019 ◽  
Vol 233 (9) ◽  
pp. 892-900 ◽  
Author(s):  
Shabnam Samsami ◽  
Peter Augat ◽  
Gholamreza Rouhi
Keyword(s):  
Finite Element ◽  
Femoral Neck ◽  
Fracture Fixation ◽  
Locking Plate ◽  
Femoral Neck Fractures ◽  
Dynamic Hip Screw ◽  
Cannulated Screws ◽  
Fixation Methods ◽  
Neck Fracture ◽  
Hip Screw

Femoral neck fractures represent a relatively uncommon injury in the non-elderly population often resulting from high-energy trauma. Clinical outcome in these patients can be improved by optimizing surgical procedures and selecting appropriate fixation methods. The aim of this study was to develop a numerical fracture model to investigate the influence of critical mechanical factors on the stability of fixation methods for femoral neck fractures. The mechanical stability of fracture fixation was assessed through employing finite element models and simulating progressive consolidation of the fracture for a vertical femoral neck fracture (i.e. Pauwels type III in which the angle between the fracture line and the horizontal plane is greater than 70°). Mechanical performance was compared among three different fixation methods (cannulated screws, dynamic hip screw with de-rotational screw, and proximal femoral locking plate). Axial femoral head displacement varied from 2.3 mm for cannulated screws to 1.12 mm for proximal femoral locking plate, although dynamic hip screw with de-rotational screw indicated a value of 0.94 mm. Considering a consolidated fracture and full weight-bearing load case, average displacements of fracture fragments were obtained of about 1.5, 3 and 70 µm for dynamic hip screw with de-rotational screw, proximal femoral locking plate and cannulated screws methods, respectively. In terms of interfragmentary movements at the fracture site, outcomes of this study demonstrated that, in agreement with our previous experimental research, the dynamic hip screw with de-rotational screw implant is a more effective choice than cannulated screws and proximal femoral locking plate techniques for vertical femoral neck fractures in young patients. Thus, one may conclude that the use of dynamic hip screw with de-rotational screw, particularly during the early stages of bone healing, could provide suitable mechanical environments that facilitate direct bone formation and shorter healing times.

scholarly journals The Role of Medial Buttress Plate Augmentation of Cannulated Screws in Unstable Femoral Neck Fractures: A Pilot Study

2021 ◽  
Author(s):  
Sayyed Hadi Sayyed Hoseinian ◽  
Ali Birjandi Nejad ◽  
Farshid Bagheri ◽  
Mohammad Taghi Peivandi ◽  
Ehsan Vahedi ◽  
...  
Keyword(s):  
Femoral Neck ◽  
Reoperation Rate ◽  
Deep Infection ◽  
Femoral Neck Fractures ◽  
Harris Hip Score ◽  
Cannulated Screws ◽  
Vein Thrombosis ◽  
Buttress Plate

Background: About 20% of femoral neck fracture surgeries require re-operation. The use of medial buttress plate may reduce the reoperation rate. The purpose of this study is to examine the results of using the method of augmentation of the cannulated screws with medial buttress plate for treatment of unstable femoral neck fractures. Methods: This study included patients with femoral neck fractures of Pauwels type 2 and 3 in which closed reduction was not successful. The patients underwent open anatomical reduction and implantation of three screws, and then the medial placement of the buttress plate was performed. Patients were followed up after 2 weeks, 6 weeks, 3 months, and 6 months. Union and fracture healing and operative complications were assessed using plain radiography. Results: This study included 8 patients with Pauwels type 2 and 3 femoral neck fractures. All patients were men with the mean age of 38.0 ± 11.3 years. Re-hospitalization 30 days after surgery, surgical site infection, deep vein thrombosis (DVT), and deep infection were not observed in any of the patients. The angle between the neck and the femur shaft dramatically increased during the 6-month follow-up (P = 0.049). Union occurred in 6 (75%) patients after 6 months, while 2 patients were lost to follow up. Participants’ Harris Hip Score (HHS) had a significant improvement from 3 months to 6 months after surgery (P = 0.02). Conclusion: Augmentation of cannulated screws with medial buttress plate for unstable femoral neck fractures in patients has advantages in short-term clinical follow-up.

Biomechanical Analysis of Augmented Plate Fixation for the Treatment of Vertical Shear Femoral Neck Fractures

2015 ◽  
Vol 29 (3) ◽  
pp. 144-150 ◽  
Author(s):  
Sarat C. Kunapuli ◽  
Matthew J. Schramski ◽  
Angela S. Lee ◽  
John M. Popovich ◽  
Jacek Cholewicki ◽  
...  
Keyword(s):  
Femoral Neck ◽  
Plate Fixation ◽  
Femoral Neck Fractures ◽  
Biomechanical Analysis ◽  
Vertical Shear

scholarly journals A comparative study of partial-threaded cannulated screws and double-threaded cannulated screws in the fixation of vertical femoral neck fractures

2020 ◽  
Author(s):  
Yuelei Zhang ◽  
Gang Wang ◽  
Wei Zhang
Keyword(s):  
Femoral Neck ◽  
Varus Deformity ◽  
Maximum Load ◽  
Femoral Neck Fractures ◽  
Vertical Shear ◽  
Axial Stiffness ◽  
Cannulated Screws ◽  
Fixation Failure ◽  
Fracture Displacement ◽  
Neck Fracture

Abstract Background This study purposed to compare the partial- threaded cannulated screws (PTCS) and the double-threaded cannulated screws (DTCS) in vertical shear femoral neck fractures both clinically and biomechanically. Methods Clinally, the radiographs of 81 patients with Pauwels Ⅲ femoral neck fractures, including 54 fractures fixed with PTCS and 27 fractures fixed with DTCS were analyzed. Complications consist of fixation failure (nail withdrawal, obvious fracture displacement, varus deformity or femoral neck shortening), bony nonunion and avascular necrosis (AVN) were determined. Biomechanically, twenty femur synthetic bones were equally divided and made to a vertical femoral neck fracture model, then fixed with three parallel PTCSs or DTCSs respectively. All specimens were tested for axial stiffness and a maximum load to failure with a loading rate of 2 mm/min. Results Clinically , 22 fractures in the PTCS group experienced fixation failure, including 19 nail withdrawal, 18 femoral neck shortening, 14 varus deformity and 8 obvious fracture displacement; while only 5 fractures showed up with fixation failure in the DTCS group, including 3 nail withdrawal, 4 femoral neck shortening, 4 varus deformity and 1 obvious fracture displacement. Additionally, 11 fractures in the PTCS group had nonunion while only 3 in the DTCS group and 9 fractures with AVN in the PTCS group while only 2 in the DTCS group. Biomechanically, The axial stiffness of DTCS was 152.89±22.74 N/mm, greater than PTCS (134.68±26.61), moreover, the failure load in DTCS was significantly greater than PTCS (1148.11±124.80 vs 795.88±162.50). Conclusion DTCS may exert more advantages than PTCS for vertical femoral neck fractures, including stronger fixation stability, lower rate of fixation failure and nonunion.

A Comparative Biomechanical Analysis of Fixation Devices for Unstable Femoral Neck Fractures: The Intertan Versus Cannulated Screws or a Dynamic Hip Screw

2011 ◽  
Vol 71 (3) ◽  
pp. 625-634 ◽  
Author(s):  
Martin Rupprecht ◽  
Lars Grossterlinden ◽  
Andreas H. Ruecker ◽  
Alexander Novo de Oliveira ◽  
Kay Sellenschloh ◽  
...  
Keyword(s):  
Femoral Neck ◽  
Femoral Neck Fractures ◽  
Dynamic Hip Screw ◽  
Biomechanical Analysis ◽  
Cannulated Screws ◽  
Fixation Devices ◽  
Hip Screw

scholarly journals BIOMECHANICAL ANALYSIS OF FEMORAL NECK FRACTURE FIXATION IN SYNTHETIC BONE

2018 ◽  
Vol 26 (3) ◽  
pp. 162-165
Author(s):  
HENRIQUE MANSUR ◽  
RAFAEL ALVAREZ ◽  
ANDERSON FREITAS ◽  
CESAR BARBOSA GONÇALVES ◽  
MAX ROGERIO FREITAS RAMOS
Keyword(s):  
Femoral Neck ◽  
Femoral Neck Fracture ◽  
Femoral Neck Fractures ◽  
Biomechanical Analysis ◽  
Type Ii ◽  
Cannulated Screws ◽  
Level Of Evidence ◽  
Synthetic Bone ◽  
Significant Difference ◽  
Neck Fracture

ABSTRACT Objectives To analyze the results of biomechanical assays of the fixation of Pauwels type II femoral neck fractures in synthetic bones, using two parallel cannulated screws or three cannulated screws in an inverted pyramid formation. Methods Ten Brazilian-made synthetic bones were divided into 2 groups. Groups A and B utilized three and two cannulated screws, respectively, after osteotomy in the middle third of the femur, perpendicular to the axis of the femoral neck, simulating a Pauwels type II femoral neck fracture. The resistance of these fixations was analyzed by compression on the axis of the force resulting from hip compression, simulated with a manual hydraulic press. The T-test and post hoc analysis were used to compare the groups, and the significance criterion adopted was p < 0.05. Results In group A, which used fixation with three screws, synthesis failure was seen at a mean force of 526 N. In group B, which used two screws, the mean force was 466 N. The results presented a statistically significant difference (p = 0.02). Conclusion The osteosynthesis of femoral neck fractures in synthetic bone fixated with two screws presented inferior results to fixation with three screws. Level of Evidence III; Case-control study.

scholarly journals Influence of the proximal screws of buttress plates on the stability of vertical femoral neck fractures: a finite element analysis

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Shi Zhan ◽  
Dajun Jiang ◽  
Jian Xu ◽  
Ming Ling ◽  
Kai Yang ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Femoral Neck ◽  
Biomechanical Properties ◽  
Femoral Neck Fractures ◽  
Cannulated Screws ◽  
Element Analysis ◽  
Proximal Screw ◽  
Buttress Plate ◽  
Plate System

Abstract Background The treatment of vertical femoral neck fractures (vFNFs) in young patients remains challenging, with a high complication rate by using traditional techniques. The use of cannulated screws (CSs) combined with a buttress plate represents an alternative approach for treating vFNFs. However, the biomechanical influence of the use or non-use of the proximal screws of buttress plates on vFNFs stability remains unclear. This study aims to analyse the biomechanics of buttress plate fixation with or without the use of proximal screws through finite element analysis (FEA) to further understand this approach. Methods We built five vFNFs (Pauwels angle 70°) finite element models treated using three cannulated screws (CS group) or three cannulated screws plus a locking buttress plate (buttress group). In the buttress group, use or non-use of proximal screws was carried out on two types of plates (4-hole & 6-hole). The following seven parameters were analysed to compare biomechanical properties of the five models: the stiffness; the maximal stress of the plate system (plate and screws), CSs and bone (MPS, MCS, MBS); the maximal displacement of internal fixations (plate system & CSs) and bone (MIFD, MBD); and the maximal relative displacement of interfragments (MID). Results Compared with CS model, the buttress models exhibited improved biomechanical properties, with increased stiffness and decreased MCS, MBS, MIFD, MBD and MID. The models fixed using buttress plates combined with a proximal screw showed greater stiffness (+ 3.75% & + 8.31% vs + 0.98% & + 4.57%) and MPS (795.6 & 947.2 MPa vs 294.9 & 556.2 MPa) values, and smaller MCS, MBS, MIFD, MBD and MID (− 3.41% to − 15.35% vs − 0.07% to − 4.32%) values than those using the same length plates without a proximal screw. Conclusions Based on the FEA results, buttress plates can improve construct mechanics, help to resist shear force and prevent varus collapse; under the modelling conditions, the use of a proximal screw on buttress plate may be a key technical feature in improving anti-shearing ability; additionally, this screw may be essential to reduce stress and prevent re-displacement of cannulated screws and fracture fragments.

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