Joint prosthesis with long service life

Profile

• What was needed: iglidur J piston rings from the iglidur product range
• Requirements: The solution should be able to absorb high radial forces, have only low wear and tear and allow for easy assembly.
• Industry: Medical technology
• Success for the customer: By using the iglidur piston ring, all work steps that occur when installing the PTFE guide tapes are omitted. They are simply clipped onto the piston, reducing assembly costs. Functionality, quality and service life of the knee joint are increased. The important sliding properties have also been significantly improved.

Problem

The PTFE guide band used so far has some disadvantages. One main problem is how to handle the PTFE guide band. This is supplied as a coil and must be cut to length in the first operation. This can result in different cutting dimensions, whereby a guide band that is too long may have to be shortened again so that it fits into the guide band groove. When cutting to size, the band may be crushed at the cutting edge, widening the height to such an extent that the band no longer fits into the groove. In this case, the band must be additionally trimmed. After cutting to length, the PTFE strips are packed and stored. Before the belts are installed, they are wound by means of a device to give them a curved shape. In use, however, the high abrasion of the PTFE guide band causes problems in long-term use.

Solution

The iglidur J piston ring made of the iglidur product range serves as a guide for the upper and lower pistons in the pneumatic cylinder in the prosthesis applications, especially in the customer's pneumatic knee joints. In doing so, it absorbs radial forces and allows the pistons a light, low-friction guidance, which influences the swing phase of the joint.
The use of the iglidur J piston ring eliminates all the work steps involved in installing the PTFE guide bands. A simple and fast clipping onto the piston facilitates the mounting of the piston ring enormously. This reduces manufacturing costs (assembly costs), which has a positive effect on the overall price of the pneumatic knee joint. After successful tests of the iglidur J piston rings, there is hardly any noticeable wear, i.e. the functionality, quality and service life of the knee joint are increased. The important sliding properties are also significantly improved.