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.
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
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
Single group
Collarless Actis femoral stem
DevicePrimary cementless total hip arthroplasty using the collarless Actis femoral stem and Pinnacle acetabular cup (DePuy Synthes, Warsaw, IN, USA) with a fourth-generation BIOLOX delta ceramic head and liner (CeramTec, Plochingen, Germany).
Incidence of orthopedic complications
Number of participants with any orthopedic complication, defined as dislocation, periprosthetic joint infection, aseptic loosening, or periprosthetic fracture.
Reoperation rate
Number of participants undergoing any reoperation or revision of the index hip for any reason.
Implant survivorship
Kaplan-Meier survivorship of the implant with reoperation or revision for any reason as the endpoint.
Modified Harris Hip Score
Modified Harris Hip Score, a measure of hip pain and function ranging from 0 to 100, with higher scores indicating better hip function.
Hip Disability and Osteoarthritis Outcome Score (HOOS)
HOOS, a patient-reported measure scored from 0 to 100 in each subscale, with higher scores indicating fewer symptoms and better function.
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Seoul National University Bundang Hospital
Lead sponsor
Johnson & Johnson Medical Korea Ltd
Collaborator
