Ming Ding1*, Jeannette Penny1,2, Carsten Jensen3,4, Ole Ovesen1 and Søren Overgaard1,5
1Department of Orthopedic Surgery and Traumatology, Odense University Hospital, Department of Clinical Research, University of Southern Denmark, Denmark
2Department of Orthopedics, Zealand University Hospital, Naestved and Koege, Denmark
3Department of Orthopedics, Kolding Hospital, Denmark
4Institute of Regional Health Research, University of Southern Denmark, Denmark
5Department of Orthopedic Surgery & Traumatology, Copenhagen University Hospital, Bispebjerg and Department of Clinical Medicine, University of Copenhagen, Denmark
Background: Preservation of bone tissues was one of the motivating factors for the introduction of Resurfacing Hip Arthroplasty (RHA). We investigated the implant fixation of ASR™ RHA compared to Large-Diameter Head arthroplasty (LDH) and standard Total Hip Arthroplasty (THA) over a 5-year follow-up. Patients and Methods: The patients included had primary or secondary osteoarthritis (age 44 to 66 years): 19 patients in the RHA group, 15 in the LDH group and 17 in the THA group. These patients were assessed by radiostereometric analysis, dual-energy X-ray absorptiometry, and whole blood analysis. Results: Total translation and rotation of cups were performed between 2 months and 5 years to allow for bedding-in. The within-group mean change for total cup translation after 5 years was 0.10 mm and 0.57 mm in the RHA and LDA groups, respectively. Small changes in Bone Mineral Density (BMD) were found for all regions of interest across the 5 years in the acetabulum and femur. A significantly decreased BMD by 1.36% annually in the RHA occurred only in the cup regions. The blood cobalt and chromium levels were significantly increased by 24 and 13 times in the RHA group. Conclusion: We demonstrated relatively stable midterm fixation of RHA compared to LDH and THA during the 5-year follow-up. Although stable fixation and lack of clinical revision indications, the elevated metal ion levels and decreased BMD behind the cup in the RHA group should be followed up to assess whether these changes will affect implant stability.
Ding M, Penny J, Jensen C, Ovesen O, Overgaard S. Stable Midterm Fixation of ASR Hip Resurfacing Arthroplasty and M2a-Magnum Cup – 5-years Follow-up on Migration, Bone Mineral Density, and Metal Ion Levels. Clin Surg. 2022; 7: 3467..