Some doubts

In order to understand well about the surgeries that I want to continue performing and I want to learn abroad, it is necessary to understand the nature of the materials and the forces to which they are subjected. An inappropriate continuous cyclic loading can generate serious consequences for the patient.

Although most cases where we operate on patients usually have satisfactory results, there is a small percentage that tends to suffer unexpected complications and undesirable for both the patient and the surgeon. Among them is the loosening or fatigue of the material we place in the surgery. The next big question is:

One issue that stands out when observing the historical evolution of osteosynthesis techniques is the progressive discrediting of the plaques. We understand that the causes must be sought in the complications that they offer. The first is the infection, obviously due to the hospital conditions and the surgical technique in general. Other causes are failures considered mechanical, which are so often attributed to the implants and which are not properly interpreted. But if we analyze the panorama in depth, we can see that the retreat of the indications from the plate to the nail has also been due to the pressure of the industry, which seems forced to innovate. Few seem to observe the increasing number of screw breaks in locked nails and the breakage of the bald people themselves at the level of their bolt holes. There are also no critical voices against the deviations that are accepted after the nails and that would be considered unacceptable if the osteosynthesis had been carried out with a plate.

For any bone, the number of screws or corticals in which to prey depends on each case, i.e., the type of fracture, the quality of the bone tissue, the immediacy with which the mechanically operated fracture is going to be requested, etc. In fact, traumatologists with long experience have progressively removed screws throughout their surgical history, as they gained experience.

The screws closest to the fracture site and the most distal are essential, as is the length and thickness of the plate, which must be proportional to the size of the bone. Intermediate screws are used to adapt the plate to the bone and distribute stresses, but they are not as important from a biomechanical point of view as the ones closest and most distal to the focus. It has also been traditionally said that the last screw of a plate must take a single cortex to facilitate a gradient of elasticity between the metal plate and the more elastic cortical bone tissue. It was a good suggestion when all the holes of the plate were filled with screws, but now that many are obviated, the extreme screw, whether proximal or distal, is very much in demand and it may be convenient to take the two cortices.

The progressive introduction of titanium as a material for the manufacture of plates and screws, makes us point out that it is not a metal more resistant to all solicitations than steels in use. It has better tolerance, the plates are more deformable and therefore mold better, suffer fatigue later than steel, but if they are continuously requested in bending also break. Titanium screws are more sensitive to the shear forces than steel, so they break more easily at neck level. They also break at this level, more easily if tightened too tightly with the screwdriver.

If you need recommendations or help in orthopedic surgery and traumatology do not hesitate to contact me.