RSA Study Using Two Types of Uncemented Acetabular Components and the Uncemented HA Coated Symax Stem

A Prospective Randomised Rontgen Stereophotogrammatic Analysis (RSA) Study Using the Uncemented Trident Tritanium Acetabular Component and the Uncemented HA Coated Symax Hip Stem in a Single Centre: Assessment of Implant Migration, Bone Remodeling and Clinical Function

The Trident Tritanium acetabular component of a total hip prosthesis is a new developed uncemented acetabular component. In this randomized controlled trial (RCT) the tritanium cup will be compared with the Trident HA acetabular component in two equal sized groups. The Symax HA coated stem will be used as femoral component in both groups.

Study Objectives:

• The primary objective is to determine the prosthetic migration of the uncemented acetabular and femoral total hip components using model based RSA technique
• Secondary objectives are on one hand to assess clinical outcome on the other hand assessing patient satisfaction in both groups using Harris Hip Score, Oxford Hip Score, WOMAC, and EQ-5D questionnaires
• Tertiary objective is to assess bone remodeling of the uncemented acetabular components and the HA-coated Symax hip stem using QCT derived from usinf F18-fluoride PET in a cohort of 12 consecutive patients of this RCT

A total of 50 patients will be enrolled in this RCT divided into two equal groups. Patients have to fulfill the inclusion and exclusion criteria.

All evaluations will be done pre-operatively with 2 weeks before surgery, and after surgery at 4 weeks, 3 and 6 months and 1 and 2 years.

Inclusion Criteria:

• Patients with a BMI < 35
• Patients requiring uncemented primary THA
• Primary diagnosis of osteoarthritis

Exclusion Criteria:

• patients with acetabular or femoral osteotomy
• Patients who had a THA on the contralateral side within last 6 months
• Female patients who are pregnant or planning pregnancy during the course of the study
• Patients with active or suspected infection
• patients with malignancy
• patients with a systemic disease that would effect the subject's welfare or overall outcome of the study
• Patients with a neuromuscular or neurosensory deficit which would limit the ability to assess the performance of the device
• Patients with systemic or metabolic disorders leading to progressive bone deterioration
• Patients with other illnesses which are likely to affect their outcome
• Patients with known sensitivity to device materials