Trends in Open vs. Endoscopic Carpal Tunnel Release: A Comprehensive Survey in Japan.

We analyzed trends in open and endoscopic carpal tunnel release (CTR) from 2014 to 2019 using the National Database of Health Insurance Claims and Specific Health Checkups in Japan (NDB). Japan has a universal health insurance system and more than 95% of all claims are searchable in the NDB open data repository. The results revealed that nearly 40,000 CTRs were performed annually in Japan, and open CTR was performed almost 4 times more often than endoscopic CTR. The crude annual incidence of CTR in the general population among people 20 years of age or older was 32.2 per 100,000. The incidence of open CTR peaked in the 80-84 age range for both males and females. The incidence of endoscopic CTR peaked at 80-84 years in females and at 75-79 years in males. There was a mild correlation coefficient between the endoscopic CTRs and the number of hand surgery specialists by prefecture per population ( = 0.32, = 0.04). However, the number of hand surgeons per capita by region and open CTR per capita was not correlated ( = 0.06, = 0.67). There were about twice as many outpatient as inpatient surgeries, reflecting a trend toward ambulatory treatment.