Investigating Proximal Migration in Trabecular Metal Cups Used In Acetabular Revision Surgery

Sahlgrenska University Hospital

Status: Completed

Conditions: Prosthesis Loosening

Treatments: Device: Trilogy cup; Device: Trabecular metal cup (TM); Device: ZCA cup

Study type: Interventional

Funder types: Other

Identifiers

NCT02237482

539-06

Details and patient eligibility

About

This study is intended to compare the proximal migration of the tantalum design (TM) with a cemented cup used in conjunction with bone allografting in cases with major bone loss. A group of patients with good periacetabular bone stock are included to analyse the differences between the tantalum and titanium design regarding risk of loosening and differences in clinical outcome measures. Radiostereometry (RSA) is used to accurately measure migration and rotation of the revision cups.

Full description

Acetabular component loosening is often associated with periacetabular bone loss. Different approaches are described to address the bone defects in acetabular revision surgery. Several authors have reported inferior results when uncemented Titanium alloys and older porous coated designs are used in acetabular revisions with significant bone loss. Cemented fixation of the revision cup with impaction bone grafting (BIG), introduced more than three decades ago has today a thorough documentation. The Tantalum designs, with inherent properties such as high volumetric porosity, low modulus of elasticity and high friction against the bone, have been suggested to improve the fixation of the acetabular component. Several authors have been reporting promising short- and medium-term results using the TM designs in acetabular revisions with large periacetabular bone defects. Proximal migration measured with radiostereometry (RSA) has been suggested to predict risk for late aseptic loosening in hip prosthesis surgery. This study was primarily to compare the proximal migration of the tantalum design with a cemented cup used in conjunction with bone allografting in cases with major bone loss. A group of patients with good periacetabular bone stock are included to analyse the differences between the tantalum and titanium design. RSA is used to accurately measure migration and rotation of the revision cups.

Enrollment: 100 patients

Sex: All

Ages: Under 85 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

All patients with a loose acetabular component, undergoing revision

Exclusion criteria

Patient not able to understand the intention of the study

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Single Group Assignment

Masking: None (Open label)

---

100 participants in 2 patient groups

Small periacetabular bone defects

Experimental group

Description:

Patients with cup loosening and small periacetabular bone defects

Treatment:

Device: Trabecular metal cup (TM)

Device: Trilogy cup

Large periacetabular bone defects

Experimental group

Description:

Patients with cup loosening and large periacetabular bone defects

Treatment:

Device: ZCA cup

Device: Trabecular metal cup (TM)