Reverse hybrid total hip replacement: Wear, fixation and bone remodelling

Description:
Reverse hybrid total hip replacement uses a cemented all polyethylene acetabular cup in combination with an uncemented femoral stem.

Background:
There has been an increasing use of reverse hybrid total hip replacement in Norway and Sweden during the last decade. Despite increasing use of this method there has been very little documentation of results.

Methods:
Register studies
Prospective randomized clinical studies
Radiostereometry
Dual energy x-ray absorptiometry
Conventional X-ray
Clinical follow up of patients

Purpose:
Main purpose is to document the current method and compare it to cemented implants

Aim:
-Study the reverse hybrid and compare it to the conventional cemented total hip replacement
-Investigate uncemented total hip replacement using a second generation highly cross-linked polyethylene.
-Our focus is on the wear of the polyethylene, fixation of the acetabulum and femoral stem and remodelling of bone around these
-By documentation of different methods our aim of research is to reduce revision surgery

Planned studies:

1 Measure wear, migration of components and bone mineral density in femur and acetabulum, in reverse hybrid THR and cemented THR. Randomized prospective study.

2 Evaluate medium-term follow up of reverse THR from the Norwegian Arthroplasty Register.

3 Evaluate wear and bone mineral density using 3. generation highly cross-linked polyethylene with 32 or 36 mm femoral head of ceramics. Prospective randomized study.

4 Method for wear measurements– study of methods.

5 NARA study on reverse hybrid THR. Study accepted by the NARA administration.

Supervisors:
Stephan M. Röhrl, MD, PhD, Orthopaedic Surgeon
Lars Nordsletten, MD, PhD, Professor, Orthopaedic Surgeon