Arthroplasty Complications
Conditions
Keywords
uncemented hip arthroplasty, osteolysis, polyethylene wear, implant design
Brief summary
In order to investigate the role of acetabular cup screw holes for the transport of osteolysis-inducing particles in a total hip arthroplasty articulation, the investigators compare the amount of bone loss around acetabular cups with and without holes. Bone loss is measured with computed tomography at 7 years and 15 - 18 years of follow-up.
Detailed description
Particles generated by wear and corrosion within an artificial hip articulation can cause biologically mediated bone loss in the surrounding pelvis. Particles can be found within immunologically active cells inside bone lesions. Holes intended for screw fixation in uncemented acetabular cups are believed to be a main route for these particles from the articulation into the pelvic bone. Using pressfit, screws are not always necessary for a successful fixation of an uncemented cup. The investigator's hypothesis is that a pressfit fixated cup without screw holes will display a decreased amount of periacetabular osteolysis compared to a cup with screw holes. Therefore, 95 hips (90 patients) were randomized to receive either pressfit cups without screw holes or the same type of cup with screw holes. The occurence and size of periacetabular osteolysis will be compared between the two groups. In addition, since the patients will have a computed tomography examination at 7 years and between 15 and 18 years the investigator will also analyze development of periacetabular osteolysis over time. The different cups were paired with three different types of femoral stems. Also, articulation wear and cup and stem fixation will be analyzed using radiostereometry.
Interventions
DEVICEUncemented acetabular cup with screw holes
DEVICEUncemented acetabular cup without screw holes
Sponsors
Zimmer Biomet
Sahlgrenska University Hospital
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
30 Years to 75 Years
Healthy volunteers
No
Inclusion criteria
* primary or secondary osteoarthritis
Exclusion criteria
* Inflammatory osteoarthritis, hip joint infection
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Periacetabular osteolysis frequency change between 7 and 18 years | Change between 7 to 18 years after surgery | Frequency of osteolysis (%) measured with computed tomography |
| Periacetabular osteolysis size change between 7 and 18 years | Change between 7 to 18 years after surgery | Size of periacetabular osteolysis (cm3) masured with computed tomography |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Cup fixation (translation) | 18 years postoperatively | Cup translation (mm/year) measured with radiostereometry, calculated from multiple measurements during the study period |
| Cup fixation (rotation) | 18 years postoperatively | Cup rotation (degrees/year) measured with radiostereometry, calculated from multiple measurements during the study period |
| Polyethylene wear | 18 years postoperatively | Polyethylene wear (mm/year) measured with radiostereometry, calculated from multiple measurements during the study period |
Outcome results
None listed