Use of dual-mobility cup in primary total hip arthroplasties: an Italian regional register (RIPO) study on three thousand, seven hundred and ten cases

Abstract

Purpose The purpose of the study was to investigate the outcome of dual-mobility cup (DM) compared with a standard cup (SC) in primary total hip arthroplasty (THA) in the long-term follow-up based on a regional Italian joint registry (RIPO). Methods The Registry of Prosthetic Orthopaedic Implant (RIPO) was consulted, looking for all primary THAs implanted from 2000 to 2019. Three thousand seven hundred ten were dual-mobility cup (DM) total hip arthroplasties (THA) and 85.816 were standard cup (SC) THAs, on a total of 89.526 primary THA. Demographics, survival rates and causes of revision were evaluated and compared between the two groups. Results The use of DM progressively increased from 0.4% in 2000 to 7.5% in 2018 of all primary THAs. Revision rate was 3.5% (128 on 3710) for DMC and 4.7% (4061 on 85,816) for SC. DM presented lower dislocation rate if compared to SC with 22–28-mm femoral head diameter. However, DM showed a higher risk of revision for any causes than SC with 32-mm femoral head diameter in long-term follow-up. Nevertheless, no significant difference was measured in terms of demographics and surgical approach for dislocation rate. Conclusions The DM cup represents a valid implant solution and has a lower dislocation rate than 22–28-mm SC. A slight increase in the use of DM implants over time was observed in the RIPO. However, a larger population and a longer follow-up are needed to further monitor the survival rate of new-generation DM implants.

Running-in behavior of dual-mobility cup during the gait cycle: A finite element analysis

“…Several in vivo studies reported that the head diameter utilized in DMC was typically smaller than 32 mm. 52,53 This head was designed to fit within a larger polyethylene hemisphere, typically from 38 to 54 mm in diameter. 52 The hemisphere was designed to articulate with a smooth metal surface.…”

Dual mobility in primary total hip arthroplasty: A temptation from the devil or a blessing from above

“…Long-term studies of first-generation DM implants have demonstrated their effectiveness in reducing the risk of revision due to dislocation compared to standard prosthetic implants. Additionally, DM constructs (DMC) have shown positive outcomes in patients with spinopelvic stiffness and neurologic disorders, making them a valuable option in specific clinical scenarios[ 1 , 2 , 13 , 14 ].…”

“…DM cups consist of three joints: The inner joint, the smaller one, between the femoral head and the polyethylene liner, the outer larger joint between the metal cup and the polyethylene liner, and the “virtual” third joint between the stem neck and the peripheral border of the liner[ 1 ].…”

“…Robust, long-term outcome studies with larger patient cohorts are essential to establish the durability and survivorship of DM implants in primary THA. Research endeavors should focus on evaluating implant performance, wear patterns, and patient-reported outcomes, and comparing the effectiveness of DM implants with traditional THA designs[ 1 ].…”

“…However, their application in primary THA remains a topic of ongoing debate within the orthopedic community. This manuscript delves into the intricacies of DM bearings, exploring their pathology, incidence, diagnosis, treatment options, prognosis, ongoing studies, and future perspectives in the context of primary THA[ 1 - 3 ].…”