Metal-on-metal (MOM) is a commonly used bearing notable for its 'suction fit' when lubricated. In this study, we examined the capacity for MOM bearings to protect against dislocation after total hip replacement (THR). We undertook a clinical investigation to compare the rate of dislocation of MOM bearings with those of ceramic-on-polyethylene (COP) bearings and found that one MOM bearing dislocated in a series of 109 hips (0.9%) compared with nine of 145 hips (6.2%) in the COP group (p = 0.02). We also performed an in vitro investigation comparing the peak forces generated during forced separation of the two bearings of the same dimensions at velocities from 1 to 50 cm/s. This revealed that the MOM bearing generated significant resistance to separation at all velocities (maximum mean 24 N), whereas the COP did not (maximum mean 1.9 N, p < 0.001). We conclude that MOM bearings are more stable to dislocation than COP bearings as a result of the interfacial forces provided by a thin, lubricating fluid.
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Cureus
October 2024
Orthopedic Surgery, Anne Arundel Medical Center, Annapolis, USA.
Background Metal-on-metal (MoM) bearing surfaces have been implicated as a cause of increased complication rates in total hip arthroplasty (THA), with local and systemic reactions identified. These reactions may cause abnormal laboratory results in common tests that are used to diagnose periprosthetic joint infection (PJI). The purpose of this study was to evaluate the utility of common laboratory studies in the diagnosis of PJI in patients undergoing revision THA with MoM bearings.
View Article and Find Full Text PDFArthroplast Today
October 2024
Department of Orthopaedic Surgery, University of Southern Florida Health Morsani College of Medicine, Tampa, FL, USA.
Acta Orthop Traumatol Turc
July 2024
Department of Orthopedics, Tianjin First Central Hospital, Tianjin, China.
This study aimed to investigate the long-term serum metal ion levels of patients who received metal-on-metal hip resurfacing arthroplasty (MoM HRA). We conducted a retrospective study of 99 patients (110 hips) from March 2006 to May 2017 who underwent MoM HRA. The Harris Hip Score (HHS) and the University of California at Los Angeles (UCLA) activity score were measured, and the patients underwent clinical and radiological management.
View Article and Find Full Text PDFJ Orthop Case Rep
September 2024
Department of Orthopaedics, Apollo Specialty Hospitals, Chennai, Tamil Nadu, India.
Arthroplast Today
October 2024
Department of Orthopaedic Surgery and Traumatology, HFR Fribourg - Cantonal Hospital, University of Fribourg, Fribourg, Switzerland.
The use of metal-on-metal bearing couples in total hip arthroplasty can lead to an increased release of metal ions, particularly cobalt and chromium over time. This can lead to local and systemic metallosis, which has cytotoxic, genotoxic, and immunotoxic effects and can cause a host of secondary disorders. We describe the case of a 37-year-old female patient that was diagnosed with warm-antibody autoimmune hemolytic anemia (WAIHA) one and a half years after bilateral large-diameter head metal-on-metal total hip arthroplasty.
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