Biomechanical considerations in preoperative planning

With the osteosynthesis indication, a declaration is made over the requirement of absolute or relative stability. While dealing with the complex fractures of diaphysis and metaphysis it becomes more important. 

In the articular fractures, absolute stability can be indicated properly which is achieved by the interfragmentary compression with the use of lag screw technique. With the buttress locking bone plate, the added stability can be achieved. With absolute stability, the simple shaft fractures can also be treated. 

It will be best to apply the reality stability on multifragmentary fractures majorly in the case of the metaphysis and diaphysis. In the case of the relative stability, appropriate shape and strength of the plate are selected. The share should conform to the anatomical surface of the bone, it is important to check this. So that the Implant and bone can act as a single construct. To prevent premature failure, strength is important. 

On a general note, the bone plates with the 4.5mm are used in femur while the narrow 5.5in plate is used in the tibia and humerus while the plate of 3.5mm is used with the radius and ulna. 

To provide balanced stability it is required to perform an ortho implant at both fracture gap sites. If a single fragment is fixed more rigidly to the bone than it can result in the stiffness to the other end of the fragment. It is one of the important concepts of the locked screw plate that needs to be checked. 

Common errors:

With the small screw numbers, the MIS can also be compared with the arbitrary that also depends on the length of the incision. The exposure is sufficient for targeting the insertion of plate and desire screw holes. There should be no exposure of the fracture but it can be reduced with the indirect methods by using the option of mini-open. 

Common errors:

● Excessive stiffness can be caused by filling more screws. 

● The use of a very short bone plate, the plate needs to spam from the metaphysis to the other. 

● The use of extremely long plates can result in the miss engaging of the proximal or distal screws with the bone. 

● Not centering the plate with the fracture site that means, one limb is longer than the other. 

● Leaving a single unfilled screw hole opposite a small bone defect. 

● Use of LHS at one side and standard screws at the other side of the LCP.