Polyethylene liners of modular acetabular components wear and sometimes need to be replaced, despite the metal shell being well fixed. Replacing the liner is a relatively simple procedure, but very little is known of the outcome of liner revision. We prospectively followed up 1126 Harris-Gallante 1 metal backed, uncemented cups for between 9 and 19 years. 38 (3.4%) liners out of 1126 acetabular components wore and required revision. These revisions were then followed up for a mean of 4.8 years. The rate of dislocation was 28.9%. Nine of the dislocations were single dislocations and 2 were recurrent.

The overall re-revision rate was 3 out of 38 total hip replacements (7.9%) at a mean follow up of 4.8 years. This gives a 92.1% survivorship at just under 5 years. In isolated liner revision we had a complication rate of 23%. In liner revision combined with stem revision we had a complication rate of 48%. Possible reasons for high dislocation rates are discussed.

Leaving the well fixed acetabular shell in-situ leads to an increased risk of instability. However, this needs to be balanced against the otherwise low complication rate for liner revision. Patients should be consented accordingly