An interventional study of Total Hip Arthroplasty in Hip Osteoarthritis, sponsored by Helse Møre og Romsdal HF. Active, not recruiting at 1 site in Norway. Open to participants aged 65 Years to 80 Years. Per ClinicalTrials.gov, last updated 2026-08-14.
Sponsored by Helse Møre og Romsdal HF · Not applicable, Interventional, and Treatment
The goal of this randomized controled trial is to compare if using of ancillary screws yields equal results as no use of ancillary screws in the ACE acetabulum cup of a total hip arthroplasty. Further, the migration of the Avanteon stem over time will be assessed. Patients included are patients with hip osteoarthritis from 65-80 years old. The purpose of this study is to compare implant migration and early fixation of a hybrid hip replacement combining the uncemented ACE acetabular component and the cemented Avanteon femoral stem, by using CT based Radiostereometric Analysis, a new innovative method for evaluating implant migration. Our study may predict the long term survival of the implants used.
Participants will go through total hip arthroplasty, and be followed by CT-RSA, plain x-rays and patients reported outcome measures.
Hip and knee osteoarthritis OA is one of the leading causes of disability worldwide. The lifetime risk of developing hip OA is estimated to be 25%, in people who reach the age of 85. Total hip replacement THR is considered to be a safe and reliable surgical treatment for end stage hip OA and was described as "Surgery of the century". One of the challenges in hip replacement surgery is to ensure the longevity and durability of the implants used. New implants are designed to improve the primary stability and long-term survival of the implant. Early failure of implants and the need for revision surgery, is a major concern. Revision hip replacement surgery is a surgical procedure with high rates of postoperative complications and overall re-revision rate of 15,8% within 1 year. In the Norwegian arthroplasty register 10 year failure rate of hip revision prostheses is 26%. Thus, the longevity and durability of implants is a continuous challenge in which the ultimate goal is to develop well-functioning implants which will last a lifetime.
The purpose of this study is to compare implant migration and early fixation of a hybrid hip replacement combining the uncemented ACE acetabular component and the cemented Avanteon femoral stem, by using CT based Radiostereometric Analysis, a new innovative method for evaluating implant migration. Our study may predict the long term survival of the implants used. This will be the first ever CT-RSA study in Norway and one of the first world-wide, evaluating hip implants.
Radiostereometric analysis RSA is a method used to measure implant migration and micromotion after joint replacement surgery, with high precision and accuracy. It is considered the gold standard for to assess migration in orthopedic implants. Early implant migration predicts later loosening, and failure of the implant. Subsidence of the femoral stem of more than 1.2 mm at 24m months is predictive of revision. Proximal migration of the acetabular component of up to 0.2mm is considered acceptable, 0.2-1mm is considered at risk, and above 1mm is unacceptable. RSA is thereby used as an early measure of longevity and durability of new implants. However, RSA is an expensive and time consuming procedure. It requires special equipment such as RSA cages, software, and special x-ray setup. It also requires specially trained personnel to do the examination. Loss of data due to occlusion of tantalum beads from metallic implants, is unavoidable in RSA. Over the last years CT-RSA has evolved to overcome some of the challenges of RSA. CT-RSA has been validated to have similar or even higher precision and accuracy than RSA in both hip and knee implant analysis.By using CT-RSA we can evaluate implant migration without the need for implant or bone markers, by using bone surface anatomy. One of the authors (FDØ) has recently shown that a vast decrease of effective radiation doses of CT-RSA in total knee arthroplasty yields equal precision in a cadaver study (publication in press). We assume this applies to CT-RSA of the hip as well. We therefore would like to perform a study on ultra low dose CT-RSA of hip implants, to evaluate the precision. This could have a major impact for future CT-RSA studies of the hip, since we potentially could reduce the effective radiation dose.
Previous cadaveric studies have shown that screw fixation increases initial stability of acetabular components. In long term, press-fit screwless fixation achieve sufficient stability.The use of augmented screw fixation may increase the risk of particle debris and osteolysis around the acetabular component. The use of ancillary screw fixation may thereby increase the risk of loosening, and need for major revision surgery. There is also a risk for iatrogenic damage to nearby vessels and pelvic organs, due to screw misplacement.
The Avanteon JRI is a highly polished double tapered femoral stem, designed by force-closed principles. The stem is intended to subside gradually in the cement mantle over time. Highly polished femoral stems have shown excellent results, and lower revision rates compared to shape-closed design stems. New implants are developed to increase early fixation and long term survival, to avoid the need for revision surgery.
In the field of orthopedic surgery, our study may predict the long term survival of the implants used, and thereby contributing to the goal of life-long lasting implants. This will also contribute to lower the need for revision surgery, avoiding the risk of major complications for our patients. The economic impact off revision surgery is of great concern for both the patient and the society, and avoiding the need for revision arthroplasty is of economic importance.
Research questions and goals In our study we will evaluate the migration of the Avanteon femoral stem using CT-RSA, to predict long-term survival. We will also evaluate the role of ancillary screw fixation of the new ACE acetabular component by using CT-RSA, to see if ancillary screw fixation increases stability of the implant. By using a patient attached accelerometer-based activity monitor ActivePAL, we can measure patient activity to see if the screw fixation has any effect on activity levels.
Hypotheses; Article 1
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Short term goals;
Results expected to be achieved during the project period;
This is a single blinded randomized controlled trial. Eligible patients referred will be evaluated for inclusion consecutively from the outpatient clinic of the research department at Kristiansund hospital.
628 studies on the registry are indexed under Osteoarthritis, Hip; 121 are open to participants now.
This study's planned enrollment of 60 is below the median of 90 across 450 interventional studies indexed under Osteoarthritis, Hip.
Browse Osteoarthritis, Hip studies →Helse Møre og Romsdal HF is the lead sponsor of 24 studies on the registry; 7 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Patients with primary hip osteoarthritis between the age of 65 and 80 years at time of surgery
Exclusion Criteria:
Patients who are unable to provide informed consent
Patients with ancillary screw fixation acetabular component
Procedure: Total Hip Arthroplasty
No ancillary screws in acetabular component
Procedure: Total Hip Arthroplasty
Surgery for total hip replacement
Also known as: ACE cup and Avanteon Stem
Translation
Proximal Y migration acetabular cup measured by CT-RSA
Time frame: 2 years
Rotation
Rotation XYZ measured by CT-RSA
Time frame: 2 years
Migration
Anterior and axial XZ migration acetabular cup measured by CT-RSA
Time frame: 2 years
MTPM
MTPM of acetabular cup
Time frame: 2 years
Stem Tr
Subsidence of stem
Time frame: 2 years
XZ translation of Avanteon stem
Migration
Time frame: 2 years
XYZ rotation
Rotation of stem in 3 dimensions
Time frame: 2 years
Difference precision
Precision CT-RSA measured by double investigations at 2 different dose levels
Time frame: 3 months
PROMs
Patient reported outcome measures like EQ-5D-5L, OHS, VAS, FJS and HOOS
Time frame: 2 years
Plan to share: Yes — Upon request with proper reasons, we will share data with other researchers including CT-RSA data and PROMs. This will of course be performed within the laws of Norway and totally anonymized.
Supporting information: Study protocol, Sap, Icf, Csr
This study is active, not recruiting, as verified in Aug 2026. You cannot join it, but the record below documents what was studied.
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Helse Møre og Romsdal HF