Abstract
Background
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.
Methods
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.
Results
The data revealed 24,822 cases of orthopaedic surgery, including 4,845 THA from 2004 to 2015. The reason for THA contained 3,343 osteoarthritis (OA, 69 %), 485 traumas (10 %), 291 loosening (6 %). THA increased from 282 cases in 2004 to 450 in 2015 year by year. They contained 3,905 cases of primary THA (81 %), 405 revision THA (8 %), and 535 bipolar hip arthroplasties (11 %). The revision contained 300 aseptic loosening (74 %), and 69 infections (17 %), and 36 dislocations (9%). The value of infections and dislocation as cause of revision THA was larger compared to the value of all revision THA between in 2004–2009 and in 2010–2015 (2.0 and 1.6 times).
Discussion
The number and rate of THA increased year by year, because of expansion of elderly people affected by OA in the super-aging society. The number of revision THA due to infections or dislocation may be still increasing year by year.
