Background
Most epidemiologic studies of anterior cruciate ligament reconstruction (ACLR) to date have been conducted in Western populations, whereas no studies have been conducted in Asian populations. In this study, the incidence and trend of ACLR in Korea were investigated through an epidemiological big data analysis.

Methods
The data were collected by the Health Insurance Review and Assessment Service from 2008 to 2016 in Korea. Patient records with the coding of cruciate ligament reconstruction were allocated, and ACLR patients were further refined by medical diagnosis coding. The total number and incidence of ACLR procedures per 100,000 person-years were investigated and more detailed analysis was conducted according to sex and age. Furthermore, concomitant surgical procedures performed during ACLR were investigated.

Results
The total number and incidence of ACLR procedures rose from 10,248 and 21.8 to 14,500 and 29.1 between 2008 and 2016, respectively. The incidence of ACLR procedures increased by 33.5% over this 9-year period. Over this period, the total number and incidence increased from 8,543 and 36.4 to 11,534 and 46.4, respectively, in males and from 1,705 and 7.2 to 2,966 and 11.9, respectively, in females. ACLR was performed more frequently in males than in females; however, the increase rate was higher in females than males. ACLR was performed most frequently in patients in their 20s, followed by patients in their 30s, 40s, and 10s. The most frequent concomitant procedures performed during ACLR were meniscectomy (13.6% in 2008 and 9.8% in 2016) and meniscal repair (5.8% in 2008 and 8.8% in 2016).

Conclusions
The incidence of ACLR consistently rose between 2008 and 2016 in Korea. The current study will enhance our understanding of the epidemiology of ACLR, which is needed to devise cost-effective preventive measures.

Keywords:Knee; Anterior cruciate ligament; Reconstruction; Epidemiology; Incidence