Fixation of fractures by Bone screw and plates has undergone design modifications and improvements during current years. The tension band principle in non-unions and the fixation of fractures was applied by Friedrich Pauwels for the 1st time. This principle of engineering applies to the change of tensile forces to compression forces on the convex side of an eccentrically loaded bone. This can be done by placing a tension band (bone plate) across the fracture on the tension (or convex) side of the bone. Tensile forces are counteracted by the tension band at this site and changed into compressive forces. If the plate is applied to the compression (or concave) side of the bone, it’s possible to bend, fatigue, and not pass. Therefore, a basic principle of tension band plating is that it must be applied to the tension side of the bone so the bone itself can receive the compressive forces.
Plates offer the benefits of anatomic reduction of the fracture with open techniques and stability for the primary function of muscle-tendon units and joints, however they need to be secured from premature weight bearing. Disadvantages of the plate fixation include stress protection and osteoporosis below a plate, the bone refracture risk after their removal, plate irritation, and in some rare cases an immunologic reaction. Plates neutralize deforming forces that may not be counteracted by solely screws. Plates require countering to keep the optimum stability of the fracture reduction. The application of the bone screws is also critical as a result of inappropriate sequence or location will result in displacement or shear and loss of reduction.
Also Read: What Is Orthopedics And Orthopedic Surgery?
A researcher named Danis was the first person to style and use a rigid longitudinal compression system that ends up in the healing of fractures without the formation of a visible callus. This sort of standard rigid plating promotes main healing through the direct compression of the plate to bone by or without a removable compressor and is now called the AO/ASIF technique (ASIF: Association for the study of internal fixation). These techniques rely upon the axial force generated by the insertion torque of spherical screw heads to compress the plate to the bone. It should be noted that not all plating devices rely upon this technique of compression. For instance, in the case of comminuted fractures, lag screws offer the essential compression through the obtaining the distal bone fragment.
Although inherently stable, DCPs even have some major disadvantages. These are: the harm caused to vascular tissue adjacent to the bone, the bending required before surgical insertion, and most significant is stress shielding in the underlying bone. some researchers advise that necrosis related to vascular insufficiency, due to the appliance of bone plates, is the primary cause of increased bone porosity. So, to decrease the harm of soft tissue, researchers sought the usage of plating devices which limit the part of contact between the plate and bone. A variation of the DCP, called the LC-DCP or locked-compression DCP systems offers stability through locked tapered screw heads whereas limiting the contact part of plate-bone. Another technique usually used to reduce stress shielding is to limit the distinction between plate and bone rigidities utilizing more flexible plating materials.
Early implants mostly consisted of stainless-steel. Interesting to notice that there is still much debate between the usage of fully rigid systems and systems with increased material flexibility. Some researchers trust that a small volume of micro-motion at the fracture site encourages more rapid fracture healing as a combination of primary and secondary healing can be done in this case. As it is a well-accepted concept, flexural rigidity relies on both on the material properties and cross-sectional part of the plating device. In terms of materials, less rigid titanium alloy devices with multiplied resistance to corrosion have proven to be helpful and are slowly commencing to replace devices of stainless-steel that previously dominated the market. The experimental proof discloses an increasing trend towards the over-all acceptance of more flexible systems, because the level of stress shielding is reduced.
Specific plate designs include tubular plates, dynamic compression plates (DCP), spoon plates, T and L plates, , large fragment locking plates, reconstruction plates, locking compression plates (LCP), distal tibia plate, locking compression plates (LCP), limited contact DCP (LC-LCP). The various different designs and kinds of plates can be grouped functionally into four categories:
Compression plates, buttress plates, neutralization plates, and bridge plates.
Neutralization plates do not seem to be a specific type of plates; however neutralization refers to how a plate functions in fixation of the fracture. A neutralization plate decreases the loading forces on a fracture by spanning the fracture and transferring the loading forces by the plate instead of through the site of the fracture. Neutralization plates are utilized in conjunction with inter-fragmentary fixation of the screw and neutralize torsional, shear forces, and bending. These are normally used in a fracture with wedge-type or butterfly fragment after interfragmentary screw fixation of the fracture’s wedge part. Plate’s stability is considerably improved by the interfragmentary screw. Common fractures fastened with neutralization plates are wedge fractures of the ulna, radius, humerus, and fibula.
Compression plates are indicated to use compression to fractures. The standard compression plate is mostly stated as a dynamic compression plate (DCP), that is a misnomer since these plates offer static compression to a fracture. The plate holes have sloped edges on the side of the hole distal from the fracture. A bone screw can be inserted within the hole at the end that is close to the fracture. This will lock the plate to the bone without moving the bone in respect to the plate. This is how the bone screw on the right of the orthopedic bone plate was inserted. The bone screws on the left side of the plate are inserted at the far end of the hole with the shank of screw touching the far hole end. As the screw is inserted, the head will be enforced to the right by the slope in the hole, making the bone in motion and its hooked up screw towards the fracture compressing.
Buttress plates are used to rigidly hold in place fractures at the tip of long bones, particularly at the ankle and knee, where the site of fracture experiences large compressive and other kind of forces. In order to offer suitable fixation, these plates are broadened and carefully contoured at joint end of the bone plate. That’s why, the buttress plates are denoted to as peri-articular plates. The periarticular surfaces of long bone are complex with numerous surfaces at each joint. Buttress plates are contoured to a surface (anterior, lateral, medial, etc.), and numerous plate designs may be required for an individual peri-articular region. There are several buttress plates, and some of the more common configurations are T-shaped, L-shaped, and bulbous end shaped plates. The contoured, periarticular part of the plate offers a three-dimensional configuration to these plates. Compression plates negate bending, torsional, shear forces and create compression across the place of fracture either through particularly designed self-compression holes within the design of dynamic compression plate (DCP). These holes exert compression through plate’s translation because the screw engages it. Siora Surgicals Pvt. Ltd is one of the top orthopaedic implants manufacturing Company in India. We have different type of orthopedic product such as Small Fragment Locking Implants, Hip Prosthesis, Interlocking Nails, Bone Screws, Locking Plates, Trauma Bone Plates, Multifix Tibia Nails, Intramedullary Interlocking Nails, Proximal Femoral Nailing Antirotation, Dynamic Hip Screw, Dynamic Condylar Screw, AFN Nailing System, Cannulated Screws, Large Fragment Locking Compression Plate, Mini Fragment Implants, Angled blade plates etc.