A newer type of artificial hip known as a “modular dual mobility” implant could reduce the risk of dislocation in patients who need a revision surgery, according to a new study from Hospital for Special Surgery (HSS).
“Our study found that the newer technology with modular dual mobility components offered increased stability, lowering the risk of dislocation, without compromising hip range of motion in patients having a revision surgery,” says Dr Geoffrey Westrich, director of research of the Adult Reconstruction and Joint Replacement Service at HSS, who conducted the study.
“Dual mobility” refers to the bearing surface of the implant—where the joint surfaces come together to support one’s body weight. Modular dual mobility implants provide an additional bearing surface compared to a traditional implant. With the dual mobility hip, a large polyethylene plastic head fits inside a polished metal hip socket component, and an additional smaller metal or ceramic head is snap-fit within the polyethylene head, explains a media release from Hospital for Special Surgery.
“Currently, there are few large-scale outcome studies on the modular dual mobility device in revision hip replacement,” Westrich notes. “We set out to determine the rate of dislocation and the need for another surgery following revision hip replacement using this implant and report on the functional outcomes.”
In the study, Westrich and his colleagues collected clinical, radiographic and patient reported-outcome information on 370 patients (average age: 65.8 years) who underwent revision hip replacement with the dual mobility implant between April 2011 and April 2017.
To be included in the final report, patients needed to be seen for follow-up for at least 2 years after their surgery, and the average follow-up was 3.3 years.
“At the latest follow-up, we found that surgery with the dual mobility implant resulted in a very low rate of instability for the revision patients, namely 2.9 percent, with good functional improvement and a low rate of reoperation,” Westrich comments. “While longer-term follow-up is needed to fully assess the newer device, in our study there was clearly a benefit provided by the dual mobility implant in the first few years following revision surgery.”
The study was presented recently at the annual meeting of the American Association of Hip and Knee Surgeons in Dallas.
[Source(s): Hospital for Special Surgery, Science Daily]