Osteolysis Development Around Uncemented Cups With or Without Screw Holes

Not Applicable

Completed

• Conditions: Arthroplasty Complications
• Interventions: Device: Uncemented acetabular cup without screw holes; Device: Uncemented acetabular cup with screw holes

• Registration Number: NCT03692351
• Lead Sponsor: Sahlgrenska University Hospital, Sweden

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.

Study Timeline

• Study Start: 1994-06-15
• Primary Completion: 2016-12-31
• Study Completion: 2016-12-31
• Study First Submitted: 2018-08-20
• Status Verified: 2018-09
• Study First Submitted QC: 2018-09-30
• Last Update Submitted: 2018-09-30
• Study First Posted: 2018-10-02
• Last Update Posted: 2018-10-02

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 95

Inclusion Criteria

• primary or secondary osteoarthritis

Exclusion Criteria

• Inflammatory osteoarthritis, hip joint infection

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Cup without screw holes	Uncemented acetabular cup without screw holes	Uncemented Trilogy cup (Zimmer, Warzaw, IN, US) without screw holes, press-fit fixation
Cup with screw holes	Uncemented acetabular cup with screw holes	Uncemented Trilogy cup (Zimmer, Warzaw, IN, US), screw fixation (2 or 3 screws)

Primary Outcome Measures

Name	Time	Method
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
Periacetabular osteolysis frequency change between 7 and 18 years	Change between 7 to 18 years after surgery	Frequency of osteolysis (%) measured with computed tomography

Secondary Outcome Measures

Name	Time	Method
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