What are the components of a screw?

Rajat Shah
Nov 8 · 3 min read

Orthopedic bone screws are used for fixing the bones, especially in the case of fractures, and have a special shape and appearance to ensure that they remain fixated for the longest time without causing any deformity. The main components of a screw include: head, shaft, and the tip, each of which has a special use as follows:

Head

It prevents the entire cancellous bone screw from sinking into the bone and comes with a buttress whose size can be altered by using a washer between the head and the bone. This enables the screw to spread the load and is ideal to be used on a soft bone. It comes with a slot that the screw to rotate easily. The screw can then be used with a twisting force and can be pushed into the bone. Check with an orthopedic locking screw supplier to know more.

The slot of the screw is available in different shapes and sizes these days, unlike the old times, which had a linear slot in the head. These days you will find screws with a hexagonal slot. This shape promotes coupling, which remains tact during the screwing process. Moreover, no axial force needs to be applied with the use of this slot, and it ensures that it fits along the corners tightly.

The lower surface of the screw has a round shape, which ensures the contact between the screw and the bones remains maximum and there is a reduction in the stress and pressure than might be applied on the bone.

Shaft

There are three diameters of the shaft which are as follows:

The core diameter is the smallest, the shaft diameter, and the thread diameter, which is the widest. However, you will also find certain screws whose threaded diameter is bigger than the shaft one or at times the same. When it comes to strength, it can be determined with the help of the smallest diameter.

Core

The threads of are projected through this part with are also the solid section. The size of the core helps in determining the resistance and the strength of the screw. Moreover, the size of the drill is also similar to that of the core diameter.

Thread

The thread is an inclined plane that can be rotated in the threaded hole so that the screw can move with a twist. Moreover, the design also helps in maximizing the contact with the screw, which eventually increases its strength.

Tip

The tip of the screw helps in cutting the thread and insert back for fixation.

Well, these were the main components of an orthopedic screw, and it is designed in a particular manner to ensure that it remains fixated to the bone without moving.

Summary

Orthopedic screws have a crucial role to play when it comes to fixing the bones that might have broken due to fracture. Read this article to learn about the different components of a screw.

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