Why is highly cross-linked polyethylene used in total hip replacement?

A total hip replacement uses a stem and ball to recreate the thigh-side joint and a shell to replace the socket side. The polyethylene liner fits inside the shell, creating the bearing surface against the ball. Its altered polymer structure is engineered to resist wear from repeated hip movement.

The liner does not work alone. Implant positioning, fixation, bone quality, muscle strength, activity, and the surrounding soft tissues all affect stability and function. The most suitable bearing combination depends on your anatomy, age, activity, and the surgeon's assessment.

Before surgery, ask which bearing surfaces are planned and why they fit your needs. After surgery, follow precautions about bending, twisting, and weight-bearing if they were prescribed. Physiotherapy helps rebuild hip and leg strength, improve walking, and practise movements that reduce strain while coordination returns.

Explore [Highly Cross-Linked Polyethylene](/materials/highly-cross-linked-polyethylene/) and [Total Hip Replacement](/treatments/joint-replacement/total-hip-replacement/) for more context.

Contact your care team for increasing wound drainage or redness, fever, new leg-length concerns, or pain that suddenly changes. Seek urgent help for a fall with inability to bear weight, a visibly deformed hip, severe calf swelling, chest pain, or sudden breathlessness.

Ask how the liner fits inside the shell, which activities are suitable during recovery, what precautions apply to your surgical approach, and how follow-up will assess hip function.