Intramedullary nailing biomechanics: Evolution and challenges

2019 ◽  
Vol 233 (3) ◽  
pp. 295-308 ◽  
Author(s):  
Natacha Rosa ◽  
Miguel Marta ◽  
Mário Vaz ◽  
Sergio M O Tavares ◽  
Ricardo Simoes ◽  
...  
Keyword(s):  
Intramedullary Nailing ◽  
Fracture Site ◽  
System Stability ◽  
Wall Friction ◽  
Medical Procedure ◽  
Future Developments ◽  
Press Fit ◽  
Mechanical Linkage ◽  
Biological Environment ◽  
The Ideal

This article aims to review the biomechanical evolution of intramedullary nailing and describe the breakthrough concepts which allowed for nail improvement and its current success. The understanding of this field establishes an adequate background for forthcoming research and allows to infer on the path for future developments on intramedullary nailing. It was not until the 1940s, with the revolutionary Küntscher intramedullary nailing design, that this method was recognized as a widespread medical procedure. Such achievement was established based on the foundations created from intuition-based experiments and the first biomechanical ideologies. The nail evolved from allowing alignment and stability through press-fit fixation with nail-cortical wall friction to the nowadays nail stability achieved through interlocking screws mechanical linkage between nail and bone. Important landmarks during nail evolution comprise the introduction of flexible reaming, the progress from slotted to non-slotted nails design, the introduction of nail ‘dynamization’ and the use of titanium alloys as a new nail material. Current biomechanical improvement efforts aim to enhance the bone–intramedullary nail system stability. We suggested that benefit would be attained from a better understanding of the ideal mechano-biological environment at the fracture site, and future improvements will emerge from combining mechanics and biological tools.

scholarly journals New Technique: A Novel Femoral Derotation Osteotomy for Malrotation following Intramedullary Nailing

2012 ◽  
Vol 2012 ◽  
pp. 1-2 ◽  
Author(s):  
S. Jagernauth ◽  
A. J. Tindall ◽  
S. Kohli ◽  
P. Allen
Keyword(s):  
Female Patient ◽  
Intramedullary Nailing ◽  
Intramedullary Nail ◽  
Femoral Fracture ◽  
Fracture Site ◽  
Distal Interlocking ◽  
Nail Insertion ◽  
Derotation Osteotomy ◽  
Walking Difficulty

A 19-year-old female patient sustained a closed spiral midshaft femoral fracture and subsequently underwent femoral intramedullary nail insertion. At followup she complained of difficulty in walking and was found to have a unilateral in-toeing gait. CT imaging revealed 30 degrees of internal rotation at the fracture site, which had healed. A circumferential osteotomy was performed distal to the united fracture site using a Gigli saw with the intramedullary femoral nail in situ. The static distal interlocking screws were removed and the malrotation was corrected. Two further static distal interlocking screws were inserted to secure the intramedullary nail in position. The osteotomy went on to union and her symptoms of pain, walking difficulty, and in-toeing resolved. Our paper is the first to describe a technique for derotation osteotomy following intramedullary malreduction that leaves the intramedullary nail in situ.

scholarly journals Extended Hypofractionated Cancer Radiation Therapy Against Aged and Non-aged Breast Carcinomas Patients

2021 ◽  
Vol 2 (3) ◽  
pp. 122-129
Author(s):  
Rawshan Ara Khatun ◽  
Julekha Khatun ◽  
Kutub Uddin Ahamed
Keyword(s):  
Radiation Therapy ◽  
Breast Carcinoma ◽  
Medical Procedure ◽  
Breast Carcinomas ◽  
Malignant Growth ◽  
Fractionated Radiation ◽  
The Ideal

We led an investigation to decide if hypo fractionated 35-days timetable of entire breast radiation is pretty much as viable. Women who bearing obtrusive breast carcinoma had gone through breast monitoring a medical procedure and resection edges were clean and partially lymph hubs were negatively approached with haphazardly relegated to get entire bosom illumination either at a control portion of 50 Gy in 15 divisions over a time of 45 days or at a portion of 45.5 Gy in 12 parts over a time of 22 days (the hypo fractionated-radiation bunch). The repetition at 36 months were 7.2% among the 301 ladies allocated to standard illumination as contrasted and 7.6% among the 312 ladies allocated to the hypo fractionated routine. At 36 months, 69.5% of ladies in the benchmark group as contrasted and 71.2% of the ladies in the hypo fractionated-radiation bunch had a decent or astounding restorative result. 3 years after therapy, sped up, hypo fractionated entire breast illumination was not sub-par compared to standard radiation therapy in ladies who had gone through breast preserving a medical procedure for obtrusive bosom malignant growth with clear careful edges what's more, negative axillary hubs. The ideal fractionation plan for entire bosom light after bosom rationing medical procedure is obscure.

scholarly journals Biomechanical Evaluation Method to Optimize External Fixator Configuration in Long Bone Fractures—Conceptual Model and Experimental Validation Using Pilot Study

2021 ◽  
Vol 11 (18) ◽  
pp. 8481
Author(s):  
Thiran Sellahewa ◽  
Charitha Weerasinghe ◽  
Pujitha Silva
Keyword(s):  
Mechanical Properties ◽  
Pilot Study ◽  
Evaluation Method ◽  
Bone Fractures ◽  
Element Model ◽  
Fracture Site ◽  
System Stability ◽  
Long Bone ◽  
Use Case ◽  
Non Union

External fixation is a commonly used method in stabilizing fracture sites. The performance of the fixator depends on how it affects the mechanical properties of the fracture site and is governed by parameters like the fixator type and fixator configuration. Identifying ideal configurations prior to surgery will help surgeons in planning the procedure, limiting the possibility of complications such as non-union. In this study, a framework has been proposed as a surgical pre-planning tool, to assist surgeons compare mechanical properties of a fracture site under different fixator configurations, and thereby identify the optimum solution. A computational tool was identified as the best method for this purpose. Cost and time of computation were given special consideration to reduce complexity in clinical settings. A pilot study was conducted on a section of the proposed framework, where the aim was to understand the feasibility of implementation. In the pilot study, a unilateral uni-planar fixator on a simple diaphyseal transverse fracture was analyzed. During the pilot study the selected fixator was tested and a few models were developed to assess system stability. The models were then compared to identify the optimum model that could be used with the proposed framework. The proposed framework provided a suitable solution for the use case and out of the models developed the simplified finite element model was identified as the best option for the use case.

Characterization of Acetabular Cup Insertion Forces in Cancellous Bone Proxy for Validation of an Invasive Sensing Model and Development of Automatic Prosthesis Installation Device: A Preliminary Study

2020 ◽  
Vol 15 (2) ◽  
Author(s):  
Kambiz Behzadi ◽  
Jesse Rusk
Keyword(s):  
Force Feedback ◽  
Primary Stability ◽  
The United States ◽  
Assistive Technologies ◽  
Medical Procedure ◽  
Implant Stability ◽  
Acetabular Cup ◽  
Total Hip ◽  
Press Fit ◽  
Preliminary Study

Abstract Total hip replacement is a widespread medical procedure, with over 300,000 surgeries performed each year in the United States alone. The vast majority of total hip replacements utilize press fit fixation. Successful seating of the implant requires a delicate balance between inserting the implant deep enough to obtain sufficient primary stability, while avoiding fracture of bone. To improve patient outcomes, surgeons need assistive technologies that can guide them as to how much force to apply and when to stop impacting. The development of such technology, however, requires a greater understanding of the forces experienced in bone and the resulting cup insertion and implant stability. Here, we present a preliminary study of acetabular cup insertion into bone proxy samples. We find that as the magnitude of force on the acetabular cup increases, cup insertion and axial extraction force increase linearly, then nonlinearly, and finally plateau with full insertion. Within the small nonlinear zone, approximately 90% of both cup insertion and extraction force are achieved with only 50% total energy required for full seating, posing the question as to whether full seating is an appropriate goal in press-fit arthroplasty. For repeated impacts of a given energy, cup displacement and force experienced in bone (measured force profile—MFP) increase correspondingly and reach a plateau over a certain number of impacts (number of impacts to seating—NOITS), which represents the rate of insertion. The relationship between MFP and NOITS can be exploited to develop a force feedback mechanism to quantitatively infer optimal primary implant stability.

PERSONALIZED FINITE ELEMENT MODELING ANALYSIS OF FEMUR BONE HEALING AFTER INTRAMEDULLARY NAILING

2016 ◽  
Vol 16 (05) ◽  
pp. 1650061 ◽  
Author(s):  
JIANGJUN ZHOU ◽  
RUI YI ◽  
MIN ZHAO ◽  
DA LIU ◽  
RENFA LV ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Intramedullary Nailing ◽  
Bone Healing ◽  
Fracture Site ◽  
Von Mises Stress ◽  
Element Modeling ◽  
Modeling Analysis ◽  
Von Mises ◽  
Healing Group

Purpose: Based on rapid modeling 1 year after intramedullary nailing, personalized finite element modeling analysis was performed to predict whether the broken ends of fractured bones would break again after nail dislodgement. Methods: A total of 10 male volunteers with femur fractures who had undergone intramedullary nailing were selected 1 year after fixation and were divided into healing ([Formula: see text][Formula: see text]5) and non-healing ([Formula: see text][Formula: see text]5) groups based on X-ray analysis. We modeled each femoral fracture and performed finite element analyses after the intramedullary nail was dislodged. Static loads and constraints were applied to each model to simulate a person standing on one leg. Results: In the healing group, the von Mises stress concentrations and stress concentration point distribution were located outside the bone healing area, indicating that the stress was not concentrated at the fracture site. In the non-healing group, the maximum von Mises stress for various materials was located in the broken ends of the fractured bone, indicating that the stress was concentrated at the fracture site. Conclusion: Personalized modeling can be used to analyze bone healing before removal of a fixator to predict the stability of the fractured bone after fixator removal and to rapidly decide whether slow walking could refracture the broken ends.

scholarly journals Elastic stable intramedullary nailing for fractures in children – principles, indications, surgical technique

2014 ◽  
Vol 87 (2) ◽  
pp. 91-94 ◽  
Author(s):  
Dana Elena Vasilescu ◽  
Dan Cosma
Keyword(s):  
Surgical Technique ◽  
Minimally Invasive ◽  
Intramedullary Nailing ◽  
Elastic System ◽  
Fracture Site ◽  
Medullary Canal ◽  
Elastic Stable Intramedullary Nailing ◽  
Invasive Technique ◽  
Fractures In Children ◽  
Elastic Nails

Elastic stable intramedullary nailing (ESIN) is a minimally invasive technique. According to this technique, two elastic nails are introduced through the metaphysis into the medullary canal, are advanced through the fracture site and impacted into the opposite metaphysis. These nails are preformed in a C-shaped manner, which allows for their precise orientation and the creation of an elastic system that resists deformation.

Analysis of Centromedullary Nailing with Implant Failure

2015 ◽  
Vol 638 ◽  
pp. 130-134 ◽  
Author(s):  
Ioan Cristescu ◽  
Iulian Vasile Antoniac ◽  
Daniel Vilcioiu ◽  
Florin Safta
Keyword(s):  
Surgical Technique ◽  
Intramedullary Nailing ◽  
Delayed Union ◽  
Fracture Pattern ◽  
Fracture Site ◽  
Implant Failure ◽  
Implantation Technique ◽  
Long Bones ◽  
Metallic Implant ◽  
Non Union

Centromedullary nailing is the most preferred surgical technique for the treatment of lower limb fractures and sometimes also on the upper extremity. It is a minimal invasive surgical intervention used mainly for long bones fractures that permits treatment without opening the fracture site thus preserving the local vascularization. With the improved knowledge and understanding of the fracture pattern and of the implantation technique good stability and rapid bone healing is obtained.We present a study on 8 patients with long bones fractures (femur, tibia, humerus) that were surgically treated with intramedullary nailing which failed due to non-union. Implant failure usually occured at 6 to 10 months after surgery. In our group of patients the primary causes of non-union was improper fracture reduction, infection and faulty surgical technique. The implant usually failed several months after loading when the nail was not sharing but bearing all the weight. In this cases the metallic implant usually fails due to fatigue in its weakest point. Loss of reduction, inadequate fixation, a need to change implant and breakage of nails were considered as implant failure.Inappropriate usage of intramedullary nailing technique will lead to nonunion or delayed union and after loading the affected limb the metallic implant will bear all the mechanical forces. This will lead to implant failure and a new difficult surgery for the patients.Revision surgery should address both the biological part and the mechanical part of bone union .

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