Hip instability is one of the early complications following total hip arthroplasty. The aetiology of hip instability is often multi-factorial. The aim of this study was to assess the efficacy of prosthesis with dual mobility system in reducing hip instability in high risk cases at a short term follow up.

A retrospective analysis was performed covering 25 total hip arthroplasties on 24 patients (5 males and 19 females) between January 2007 and August 2008. Patient medical records and imaging were reviewed, and the indications for surgery and surgical outcome were analysed.

Among 25 procedures performed, 18 were revision procedure for dislocations, loosening, peri-prosthetic fractures. Seven patients have primary procedure, among which two were for acute hip fractures. One patient underwent conversion from previously failed screw fixation for hip fracture. The 25 patients were followed up for a mean period of 12 months (ranging from 4 to 24 months). At the last follow up, all patients were able to mobilise pain-free either independently, or with aids; no patients presented an episode of hip instability.

The result of our study demonstrated good early stability of total hip arthroplasty with dual mobility system (POLARCUP).