# Cemented implantation of a dual mobility cup in an existing acetabular cup to prevent recurrent dislocation after total hip replacement

## TL;DR

This study evaluates a technique for preventing hip dislocation after hip replacement surgery using a dual mobility cup implanted in an existing acetabular cup.

## Contribution

The study introduces cementing a dual mobility cup in a pre-existing acetabular cup as an alternative to direct bone implantation.

## Key findings

- Cementing a dual mobility cup in a fixed acetabular cup showed similar outcomes to direct implantation into bone.
- The technique was effective in reducing dislocation rates in older patients undergoing revision hip replacement.
- No significant differences were found between the two implantation techniques in clinical outcomes.

## Abstract

Recurrent hip dislocation is a common complication following total hip arthroplasty (THA). The dual mobility cup (DMC) technique was introduced to reduce the risk of dislocation. Cementing DMC in a fixed acetabular cup may be a good alternative to the usual approach of implanting it directly into bone. We aimed to evaluate the outcome of DMC in preventing recurrent THA dislocation. In addition, we examined differences in clinical outcomes between the two techniques: cementation into a pre-existing acetabular cup versus direct implantation into bone.

The sample comprised 20 patients who underwent surgery using the DMC technique between 2014 and 2023. The primary endpoint was time to the occurrence of postoperative revision operation for any reason, assessed by the Kaplan-Meier survival analysis with a significance threshold of p  < 0.05.

This retrospective comparative study included a total of 20 patients: 10 with a cemented DMC in a fixed acetabular cup and 10 with cementation directly in bone. Each patient experienced at least one hip dislocation following THA. The mean age of the patients was 77.65 years. The mean follow-up duration was 9.91 ± 17.01 months. The average number of preoperative dislocations was 2.90 ± 1.97. A comparison between the outcomes of the two techniques showed no significant differences.

Cemented DMC has shown favorable results in recent years, particularly in reducing the dislocation rate following revision THA in older patients. This makes it a valuable option to prevent more extensive surgery. Cementation in a fixed acetabular cup showed similar outcomes to the conventional approach, with no noticeable drawbacks.