The rate of elderly people over 65 year-old increased from 18.5 % in 2004 to 26.0% in 2015 in Japan. Northern part of Japan is a head of the super-aging society, and the rate already reached 30.9% in 2015. Along with aging society, rapid increase of total hip arthroplasties (THA) has been predicted. The aim of this study is to estimate the trend of total hip arthroplasties in our super-aging area in Northern Japan. Trend on number and rate of THA in one of the local area of leading super-aging society were surveyed in the last decade using the database of diagnostic procedure and surgical records from 2004 to 2015. The cause of revision THA was analyzed in 2004–2009 versus in 2010–2015. Spearman's rank-correlation coefficient and student's t-tests were performed using the PASW 18 software (SPSS Institute Inc). Values of p < 0.05 were considered statistically significant.Background
Methods
Large head metal on metal total hip arthroplasty MOM THA have been consistently shown substantial improvement in wear performance compared with metal on polyethylene articulations. Large diameter femoral heads theoretically can reduce dislocation risk by increasing range of motion before impingement, increasing prosthetic jump distance. However, early failure associated with adverse local tissue reactions (ALTRs) to metal debris is an emerging problem after MOM THA. The purpose of this study was to evaluate mid-term results of MOM THA. Twenty-five patients, 28 hips were included in this study. The average age of the patients at the time of surgery was 66.9 years. Three patients were men and 22 were women. MOM THAs were performed using 28 PINNACLE Cup system (DepPuy) (C-STEM: 23, S-ROM: 5) with posterior approach and head size of 36mm. Twenty-five primary THAs due to osteoarthritis in 22 cases and rheumatoid arthritis (RA) in one, and two revisions due to recurrent dislocation THA patients, were performed. The average follow up was 56.7 months. Evaluation items are JOA score, cup anteversion /lateral opening angle, and complications. Indication of the system were applied for patients with high risk of dislocation such as recurrent dislocation in primary and/or THAs, posterior pelvic tilt, elderly, RA and mental disorders.Background
Materials and Methods
