The use of total knee arthroplasty (TKA) has increased substantially in most Western countries. However, the trends in TKA use and changes in demographic characteristics of patients having TKA in Korea remain unclear. We documented the trends in TKA use and in the demographics of patients undergoing TKA in Korea over the past decade and determined whether current TKA use in Korea corresponds to worldwide trends. Using the Health Insurance Review and Assessment Service of Korea database, we analyzed TKA records (n = 398,218) from 2001 to 2010 in Korea. Trends in TKA use and demographics, including numbers and rates of primary and revision TKA, growth rate and the revision burden, and age- and sex-specific rates, were estimated. They were compared with nationwide TKA registry reports from other countries, and a systematic review was performed. Over the past decade, the primary and revision TKA rates increased by 407% and 267%, respectively. However, the revision burden remained 2%. The highest proportion was observed in 65 to 74 years old and the greatest increase in 75 to 84 years old, but a decrease was observed in those 55 to 64 years old. Women consistently had a ninefold higher TKA rate. The primary TKA rate was comparable with that of other countries, but the revision burden remained lower. In addition, old and female patients comprised considerably higher proportions in Korea. During the past decade, TKA use in Korea has markedly increased and caught up with the use levels of most developed Western countries. Trends toward consistent growth in elderly patients and higher rates in females were observed. Appropriate healthcare strategies reflecting these trends in demographics are urgently needed in Korea.

Background: Unexplained postoperative pain is one of the most feared complications of total knee arthroplasty (TKA). A persistent noxious peripheral stimulus, such as the pain of chronic knee osteoarthritis, can cause central sensitization in which the central nervous system becomes hyperexcitable, resulting in hypersensitivity to both noxious and non-noxious stimuli. Patients with central sensitization may be more susceptible to unexplained pain after TKA. Duloxetine, a selective serotonin norepinephrine reuptake inhibitor (SNRI), can ameliorate the pain associated with central sensitization, and we aimed to determine whether it could reduce postoperative pain and improve quality of recovery after TKA in patients with central sensitization. Methods: Patients undergoing TKA were screened for central sensitization preoperatively with use of the Central Sensitization Inventory (CSI). Among 464 patients with primary osteoarthritis who were scheduled for primary unilateral TKA, 80 were identified as being centrally sensitized and were included in the study. Forty patients were randomly assigned to the duloxetine group (30 mg 1 day before surgery and for 6 weeks after surgery), and 40 were randomized to the control group (no duloxetine). Pain and quality of recovery were assessed with use of the Brief Pain Inventory (BPI), the Short Form-36 (SF-36), the Measure of Intermittent and Constant Osteoarthritis Pain (ICOAP), and the Hamilton Depression Scale. The prevalence of adverse medication effects was also noted. Results: The patients in the duloxetine group had better performance across pain metrics during the initial 2 to 12-week postoperative period (p < 0.05). The duloxetine group also had a superior quality of recovery 2 weeks after TKA, as indicated by emotional and physical functioning (all p < 0.05). There was no difference between groups in the prevalence of adverse events. Conclusions: A substantial number of patients are centrally sensitized before TKA. Surgeons should consider selective incorporation of duloxetine into the multimodal postoperative analgesic protocol, according to the severity of central sensitization, to minimize the possibility of persistent pain following TKA. Level of Evidence: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

In Jun Koh, MD, Young Jun Choi, MD, Man Soo Kim, MD, Hyun Jung Koh, MD, Min Sung Kang, MD, and Yong In, MD. Knee Surg Relat Res 2017;29:87-95. https://doi.org/10.5792/ksrr.16.039