The contact pressure of ultra-high-molecular-weight polyethylene cables is twice as high as that of titanium cables

Background

Metal cables exhibit favorable clinical performance because of their high fixing force. Cables composed of ultra-high-molecular-weight polyethylene (UHMWPE) are relatively new and were first used for trauma around 2010; only a few cases involving the use of UHMWPE cables have been reported. Surgeons need to know whether the fixing force of UHMWPE cables is higher or lower than that of metal cables. This study aims to compare the fixing forces of UHMWPE cables and a titanium cable using the contact pressure as an index.

Method

We studied UHMWPE cables with widths of 3 mm and 5 mm and a titanium cable. A thin pressure sensor was set on the femoral diaphysis, and the cables were wrapped on simulated tissues and tightened with clamping forces based on the indication values displayed on the tensioner of each cable. During osteosynthesis, tissues can remain unremoved depending on the fracture site and procedure. Sus scrofa domesticus thigh tissues with thicknesses of 2 mm and 5 mm were prepared for simulating tissues, and the contact pressures in cases with and without tissues were compared.

Results

When no tissues were remained, the contact pressure of the titanium cable with a clamping force of 50 kgf was equal to that of the UHMWPE cables with a clamping force of 30 kgf. When tissues were remained, the contact pressure of the titanium cable with a clamping force of 50 kgf was twice as high as that of the UHMWPE cables with a clamping force of 30 kgf.

Conclusion

It was revealed that the contact pressure of UHMWPE cables clamped with the maximum force was twice as high as that of metal cables. This result is expected to contribute toward the selection of cables according to a desired clamping force.