Developing a Needle-Knife Surgical Device


 Introduction: Nowadays, a new era of orthopedic surgery is taking place. Procedures like video surgery, ultrasound-guided interventions, invasive pain interventions, orthopedic procedures, hydro dissection, dry needling, thermography-assisted pain management, and modern acupuncture started to be widely performed1,2. Background: In 2011 and 2012, Ravaglia & Cliquet presented papers on an Arthroscopic Needle-Knife Surgical Prototype Device (ANKSD)2 in Prague, TWC 20112, and in Dubai, OWC 20123. It was a paper presenting a prototype of a needle-knife for orthopedic procedures based on an 18G11/2 needle. Ravaglia and Cliquet wrote the paper “Comparison of two different needles used as knife on knee arthroscopic portal scalpel procedures”4, which was presented at the XXVI SICOT Triennial World Congress, in Guangzhou, China, in 2015. This research compares arthroscopic portal incisions using an 18G11/2 needle or a metal guide intravenous catheter 14Gx2. They concluded that there were no differences in complications such as infections, wound healing, hematoma, and skin healing time. After this, these researchers started a virtual development of a new needle-knife surgical device. Objective: The aim of the project is a virtual development of a needle-knife surgical device to be useful for minimally invasive ultrasound-assisted orthopedic surgical procedures, videos arthroscopic portals augmentation, and other surgical procedures. Method: Three different needle devices were compared. One is a base model 1 and the other two are experimental models (2 and 3). They are based on a metal guide for intravenous catheter 14Gx2''. The base one model 1 is the metal guide for intravenous catheter 14Gx2''; the experimental model 2 is a flat beveled edge, and experimental model 3 is a board bevel edge6,7,8,9,10,11,12,13,14,15,16. They are all graduated, parylene-coated, with a stop handle needle guard. The devices are multifunctional: Infusion, aspiration, and surgical sever.The devices were developed by 3D Design 3D STEP Standard Format, Catia V5 Format, and 2D Format Design and 3D Model. They were performed through simulation (Software Simulia Abaqus). They were biomechanically simulated with Virtual Biomechanical Strength Simulation17,18,19,20. The Strengths were assessed by Needle Strength Analysis (CAE Simulation)21.Results: For the displacement result, stiffness assessment, we have 7.48 mm for the baseline needle, 8.08mm for model 2, an increase of 8%, and for model 3 we have 7.75 mm, an increase of 3.6%. Conclusion: These devices seem suitable for echo-assisted orthopedic surgery interventions and other procedures according to virtual analysis. Further in vivo procedures shall be performed.

The Strengths were assessed by Needle Strength Analysis (CAE Simulation) 21 .

Results:
For the displacement result, stiffness assessment, we have 7.48 mm for the baseline needle, 8.08mm for model 2, an increase of 8%, and for model 3 we have 7.75 mm, an increase of 3.6%.

Conclusion:
These devices seem suitable for echo-assisted orthopedic surgery interventions and other procedures according to virtual analysis. Further in vivo procedures shall be performed.

Introduction:
Nowadays, a new era of orthopaedic surgery is taking place. Procedures like video surgery, ultrasoundguided interventions, invasive pain interventions, orthopaedic procedures, hydrodissection, dry needling, thermography-assisted pain management, and modern acupuncture started to be widely performed 1,2 . Background: In 2011 and 2012, Ravaglia & Cliquet presented papers on an Arthroscopic Needle-Knife Surgical Prototype Device (ANKSD) 2 in Prague, TWC 2011 2 , and in Dubai, OWC 2012 3 . It was a paper presenting a prototype of a needle-knife for orthopaedic procedures based on an 18G11/2 needle. Ravaglia and Cliquet wrote the paper "Comparison of two different needles used as knife on knee arthroscopic portal scalpel procedures" 4 , which was presented at the XXVI SICOT Triennial World Congress, in Guangzhou, China, in 2015. This research compares arthroscopic portal incisions using an 18G11/2 needle or a metal guide intravenous catheter 14Gx2. They concluded that there were no differences in complications such as infections, wound healing, hematoma, and skin healing time.
After this, these researchers started avirtual development of a new needle-knife surgical device.

Objective:
The aim of the project is a virtual development of a needle-knife surgical device to be useful for minimally invasive ultrasound-assisted orthopaedic surgical procedures, videos arthroscopic portals augmentation, and other surgical procedures.

Method:
Three different needle devices were compared. One is a base model 1 and the other two are experimental models (2 and 3). They are based on a metal guide for intravenous catheter 14Gx2''. The base one model 1 is the metal guide for intravenous catheter 14Gx2''; the experimental model 2 is a at beveled edge, and experimental model 3 is a board bevel edge 6,7,8,9,10,11,12,13,14,15,16 . They are all graduated, parylene-coated, with a stop handle needle guard.
The devices are multifunctional: Infusion, aspiration, and surgical sever.
The devices were developed by 3D Design 3D STEP Standard Format, Catia V5 Format, and 2D Format Design and 3D Model.
They were performed through simulation (Software Simulia Abaqus).
They were biomechanically simulated with Virtual Biomechanical Strength Simulation 17,18,19,20 . The Finite Element Method (FEM) is a numerical process to determine approximate solutions of boundary values of differential equations. FEM subdivides the problem domain into smaller problems, called nite elements. Finite element models can be formed by quadrilateral, triangular, hexahedral, and tetrahedral elements.
In structural analysis, the purpose of the method is to determine nodal displacements in the structure and, consequently, the deformities and stresses corresponding to the analysis. This way, a discretization of the continuous medium allows the solution of high-complexity real problems. This discretization is popularly known as nite element mesh, which can be of various types, such as two-dimensional and threedimensional elements.
The two-dimensional elements or 2D elements can be formed through the triangular or quadrilateral element (shown in the gure below), which discretize at surfaces such as plates, where one of the dimensions is much smaller than the other two.
Three-dimensional elements or 3D elements can be formed through the tetrahedral or hexahedral element, used in meshing solids of complex geometry. Figure 1 For the needles mathematical model, 2D and 3D elements were used as quadrilateral, triangular and tetrahedral elements, with the respective total amounts of elements shown below. Figure 2 The load applied was 10N; however, this value may be different during the use of the needle, but for checking the comparative stiffness among the models, it is an adequate value. The objective is to generate stresses and displacements and to compare in percentage baseline and proposal models 1 and 2. This loading is applied to a nite element model node at the tip of the needle in the Y-axis direction to generate stresses and displacements in the same direction of use of the needle scalpel. Figure 3 The restrictions applied to the model were displacement in the x-, y-, and z-axes, only on the needle xation region on the syringe on the plastic region of the needle, considering this as the only region that 'holds the needle'. This displacement restriction is done through rigid connectors and displacement = 0 at the Node of this connector. The connector represents, in a simpli ed way, the region where the syringe ts. Figure 4 The material adopted for the needle was SAE1020 and for the plastic part PET (polyethylene terephthalate). Although the speci c properties of the product, not found in the bibliography, were not used, this consideration does not change the analysis technical conclusions, as we are doing a comparative study.
To calculate stiffness, the solver used was the Abaqus 2019. Abaqus is a commercial software package for nite element analysis (CAE) developed by HKS Inc., Rhode Island, USA, and is currently marketed by SIMULIA under the brand of Dassault Systèmes S.A. Figure 5 After the model is discreetly with the necessary boundary conditions, the matrix calculations that will give us the nodal displacements are performed. The matrix notation expressing these nodal displacements in relation to the external forces applied to the structure is formed by a set of linear algebraic equations, being expressed in matrix form by the equation below. As a result, below we can see that stress distribution along the needle remains the same in the three models, but at the tip of the needle where models 2 and 3 were modi ed, they present slightly higher values due to the decrease in thickness because of the bevel shape. We have the baseline at 164 Mpa, model 2 at 221 Mpa, and model 3 at 190 Mpa.
For the displacement result, stiffness assessment, we have 7.48 mm for the baseline needle, 8.08mm for model 2, an increase of 8%, and for model 3 we have 7.75 mm, an increase of 3.6%. Figure 6 As a comparative evaluation, it can be stated that model 3 showed characteristics that are very similar to the baseline model in terms of stiffness (3.6%). This means that the performance during its application in relation to the baseline (reference) will be very similar. Figure 7 Regarding the stresses obtained, model 3 showed an increase of 15% due to the reduction in thickness generated by the bevel shape, but it is unlikely that a needle tip fracture will occur, considering there is no such problem in the baseline model.  Model 3 presented similar stiffness features compared to the baseline model 1 (3.6%). They have similar performance. Figure 9 The tip of model 3 showed increased tension of 15%; but this does not mean fracture risk 22 . Figure 10 Discussion: We live in a new era of orthopaedic surgery. Procedures like Video Surgery, Ultrasound-Assisted Surgical Interventions; Invasive Pain Interventions for Orthopaedics; hydrodissection, dry needling, thermographyassisted pain procedures, and modern acupuncture procedures started to be widely performed 1,2 .
During my medical training in Brazil, busy hospitals faced shortage of basic equipment in the casualty department. Most of them due to logistic issues. It was evidence-based practice to use a 'pink needle' "for abscess drainage, small incisions, and suture removal". Based on this evidence-based practice, this They decided to develop a new device with the strength of the metal guide intravenous catheter 14Gx2, the cutting edge similar to the ANKSD, and strong enough to perform orthopaedic ultrasound-assisted procedures. It is a multifunctional, echo translucent, graduated device, able to aspirate and inject uids, anesthesia, and therapeutic medicine.
The development of this device aims at incision target precision, avoiding soft tissue damage, facilitating ultrasound-assisted surgery, and being a multifunctional tool.
Virtual experiments were developed before in vivo studies.

Conclusion:
These devices seem suitable for echo-assisted orthopaedic surgery interventions and other procedures according to virtual analysis. Further in vivo procedures shall be performed. Figure 1 Two-dimensional elements or 2D elements Quadrilateral element Node Nodal line Triangular element (b) Two-dimensional Three-dimensional elements or 3D elements Hexahedral element Nodal Plane Tetrahedral element (c) Three-dimensional Source: Chapra (1997) Figure 3 Page 11/14

Figures
The three Models and their elements: Model 1: total 149553 elements Model 2: total 147138 elements Model 3: total 147218 elements NOTE: All models have an inner stem as a reinforcement for the needle structure modelled as 3D tetrahedral elements.    Strength tests results in all three models Figure 10 Strength tips tests stress results in all three models