Hip replacement with the collarless Actis stem in adults with hip damage
Follows adults having hip replacement with the collarless Actis stem for 5 years.
Plain-language title generated from the registry record
Registry title: Clinical Outcomes of Primary Cementless Total Hip Arthroplasty Using the Collarless Actis Stem
Key facts
- Where
- Seongnam-si, South KoreaSee the site
Where in South Korea
- Seoul National University Bundang HospitalSeongnam-si, South KoreaTaking people
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Trial details
- Who runs it
- Seoul National University Bundang Hospital
- Trial code
- NCT07828080
- Record updated
- 18 September 2026
- Original description
This study looks at how well a hip replacement using the collarless Actis stem works over five years.Read full original descriptionShow less
Prospective Cohort Study of Primary Cementless Total Hip Arthroplasty Using Actis Stems
This study looks at how well a hip replacement using the collarless Actis stem works over five years.
Total hip replacement is a common operation for people whose hip joint has been damaged by arthritis, by loss of blood supply to the hip bone, or by a broken hip. During the operation, the damaged parts of the hip are replaced with artificial parts. The Actis stem is the part that is fitted into the thigh bone. It is designed to bond directly with the bone, without the use of bone cement.
The Actis stem is already used in many countries, and early results have been good. However, almost all of those results come from Western patients, and most studies used a version of the stem that has a small collar. Very little is known about how the collarless version performs in Asian patients, who tend to be younger at the time of surgery and more often have the operation because of loss of blood supply to the hip bone.
People aged 18 years or older who are already scheduled for a hip replacement at this hospital may take part. Everyone who takes part has the same operation, with the same set of artificial parts. No extra tests are done for research purposes.
After surgery, participants return to the clinic at 6 weeks, 3 months, and 12 months, and then once a year until 5 years have passed. These are the same visits that patients would have anyway. At each visit, the study team checks for any problems with the new hip, takes routine X-rays, and asks participants to fill in questionnaires about their hip pain, their daily activities, and their overall health.
The main question the study asks is how many participants have a problem with the new hip within five years, such as the hip coming out of place, an infection, a break in the bone around the implant, or the implant becoming loose.
Inclusion: Age 18 years or older; Scheduled to undergo primary total hip arthroplasty for one of the following: osteoarthritis of the hip, developmental dysplasia of the hip, rheumatoid arthritis, non-rheumatoid inflammatory arthritis, post-traumatic arthritis, osteonecrosis of the femoral head, or displaced femoral neck fracture; Willing and able to provide written informed consent.
Exclusion: Age under 18 years; Total hip arthroplasty performed with a femoral stem other than the collarless Actis stem; Severe medical comorbidity precluding participation; Unwilling to participate in the study.