Abstract
Introduction
Dislocation as a primary cause of revision has been on the increase in Sweden (14% in 2014). The increasing use of Dual Mobility cups (DMC) could well be explained by the increased revision burden due to dislocation, patients undergoing revision having increased comorbidities and reports that dual articular cup designs reduce the risk of dislocation. The aim of this study was to analyze the change in utilization pattern of the dual articular designs used in acetabular revision surgery in Sweden. The short-term survival of DMC was compared to traditional designs.
Patients/Materials & Methods
During years 2004–2014, 1111 (925 cemented) revisions performed with a DMC design were reported to SHAR. About half (n=426) of these cases were first time revisions performed due to dislocation. During the same time period 520 dislocations were revised for dislocation using a standard cemented cup. There was no differences regarding the age, gender and primary diagnosis (p≥0.12) between the two groups. A second cup revision for all reasons and specifically for dislocation was used as end-point. Kaplan-Meier analysis was performed.
Results
Survival analysis at 5 years for all reasons (91.6% versus 87.9% p=0.002) and especially for reoperation because of instability (96.7 versus 90.9 p<0.0005) favors the DMC group.
Discussion
We found a lower risk for a second revision when a dual mobility cup is used in revisions performed due to dislocation.
Conclusion
Our findings indicate that use of a cemented DMC could be considered in first time revisions performed due to dislocation. Longer follow-up is needed to establish any long-term clinical advantages when dual mobility cups are used in revisions.
