Abstract
Previous scientific studies have highlighted how coupling is an important element affecting total hip arthroplasty's survival.
This study aims to evaluate whether metal-on-metal (MOM) coupling could be a statistically significant risk factor.
The data from the regional joint registry (Registro dell'Impiantologia Protesica Ortopedica, RIPO) was used for analysis. The data collection accuracy of this registry was 97.2% in 2017.
We retrospective evaluate all MOM total hip arthroplasties (THAs) implanted in our department between January 01st 2000 and December 31st 2011. We used a control group composed by all other prosthesis implanted in our Department in the same time lapse.
We registered 660 MOM THAs. Mean age of patients was 66.9 years. 603 patients have a >36mm head, while 78 a <36 mm one. Neck modularity was present in half of patients. 676 implants were cementless. We registered 69 revisions, especially due to aseptic mobilization (16 THAs), implant breakage (9 THAs) and periprosthetic fracture (6 THAs).
The MOM THAs overall Kaplan-Meier survival rate was 87.2 at 15 years, and the difference between MOM THAs and other implants two curves is statistically significant (p<0.05). Male sex is a significant risk factors. Further evaluations are in progress to establish the presence of any additional risk factors. We think weight and/or BMI may be included in this category.
Our study confirms the data currently present in the literature regarding a lower survival of metal-on-metal hip prostheses.
The male sex is a statistically significant risk factor (p<0.05), while age, head size and modularity of the prosthetic neck are not statistically significant (p>0.05).
Any new finds will be presented at the congress venue.
