Metal-metal Articulations Versus Standard 28 mm Cementless Total Hip Arthroplasty

Metal-metal Articulations vs Standard 28 mm Cementless Total Hip Arthroplasty in Younger Patients. Randomized Studies

Younger hip patients often need revision of their hip replacement due to wear and loosening. Newer concepts (resurfacing and large head total hip replacement) with articulation surfaces in metal may reduce the wear, increase the longevity of the implant and give an improved function. The possible downside is that these concepts releases metal debris to the body. The investigators wish to see if the newer interventions are a clinical improvement compared to standard. The investigators also wish to investigate the extent of metal released to the body and any effect on the immune system. Finally the investigators wish to investigate the stability of these new implants and their ability to preserve the bone around the implant. The investigators hypothesis is: That the metal on metal articulations will not have better clinical outcomes than standard The resurfacing implant is expected to preserve the bone of the upper femoral bone. The implants are expected to be stabile within the first year.

a hip replacement that leaves most of the underlying bone intact and mimics the natural biomechanical features of the hip joint

radiostereommetry. Measurement of micromotions (subsidence, rotation and translations)of the implant in relation to the bone

Harris hip score. An investigator asssesed hip questionnaire including pain, function, deformities and range of motion

University of California Los Angeles activity score. A score over the intensity of activities the patient engages in.

Inclusion Criteria: Primary hip osteoarthritis Secondary osteoarthritis due to mild dysplasia Age from 40 to 65 years Exclusion Criteria: Dysplasia with CE angle < 25 degrees on the AP projection Severe femoral head deformation Reduced femoral neck length Leg length discrepancy more than 1 cm Need for restoration of offset Deformation after fractures or earlier osteotomies A previous hip arthroplasty Inflammatory arthritis Endocrinological disease with bone metabolic manifestations Renal disease Malignant disease Neuro/muscular or vascular diseases of the affected leg Osteoporosis Use of opioid pain killers due to other diseases High dose corticosteroids Obese with BMI > 35 Pregnant or planning to be Ppresented problems that would prevent completing our follow-up program

Penny JO, Varmarken JE, Ovesen O, Nielsen C, Overgaard S. Metal ion levels and lymphocyte counts: ASR hip resurfacing prosthesis vs. standard THA: 2-year results from a randomized study. Acta Orthop. 2013 Apr;84(2):130-7. doi: 10.3109/17453674.2013.784657.

Penny JO, Ovesen O, Varmarken JE, Overgaard S. Similar range of motion and function after resurfacing large-head or standard total hip arthroplasty. Acta Orthop. 2013 Jun;84(3):246-53. doi: 10.3109/17453674.2013.788435. Epub 2013 Mar 26.

Nissen T, Douw K, Overgaard S. Patient-reported outcome of hip resurfacing arthroplasty and standard total hip replacement after short-term follow-up. Dan Med Bull. 2011 Oct;58(10):A4310.