Background: Although total knee arthroplasty (TKA) is considered an effective treatment for knee osteoarthritis, it carries risks of complications. With a growing number of TKAs performed on older patients, understanding the cause of mortality is crucial to enhance the safety of TKA. This study aimed to identify the major causes of short- and long-term mortality after TKA and report mortality trends for major causes of death. Methods: A total of 4,124 patients who underwent TKA were analyzed. The average age at surgery was 70.7 years. The average follow-up time was 73.5 months. The causes of death were retrospectively collected through Korean Statistical Information Service and classified into 13 subgroups based on the International Classification of Diseases-10 code. The short- and long-term causes of death were identified within the time-to-death intervals of 30, 60, 90, 180, 180 days, and > 180 days. Standard mortality ratios (SMRs) and cumulative incidence of deaths were computed to examine mortality trends after TKA. Results: The short-term mortality rate was 0.07% for 30 days, 0.1% for 60 days, 0.2% for 90 days, and 0.2% for 180 days. Malignant neoplasm and cardiovascular disease were the main short-term causes of death. The long-term (> 180 days) mortality rate was 6.2%. Malignant neoplasm (35%), others (11.7%), and respiratory disease (10.1%) were the major long-term causes of death.Men had a higher cumulative risk of death for respiratory, metabolic, and cardiovascular diseases. Age-adjusted mortality was significantly higher in TKA patients aged 70 years (SMR, 4.3; 95% confidence interval [CI], 3.3–5.4) and between 70 and 79 years (SMR 2.9; 95% CI, 2.5–3.5) than that in the general population. Conclusions The short-term mortality rate after TKA was low, and most of the causes were unrelated to TKA. The major causes of long-term death were consistent with previous findings. Our findings can be used as counseling data to understand the survival and mortality of TKA patients.

Background: The Forgotten Joint Score (FJS) is a newly developed patient-reported outcome measure designed to evaluate clinical outcome after total knee arthroplasty (TKA). The FJS is known as a sensitive test with a low ceiling effect. It has been recently translated into many languages. However, no study has reported the validity or reliability of a Korean version of the FJS (K-FJS). Thus, the purpose of this study was to address this issue. Methods: According to guidelines for cross-cultural adaptation, translation of the English version of the FJS was performed. After obtaining a license from the original developer, 150 patients who had undergone TKA at more than 1 year to less than 5 years ago completed the K-FJS, visual analog scale, Western Ontario and McMaster Universities Osteoarthritis index (WOMAC), and the 36-Item Short Form (SF-36) health survey. To measure test-retest reliability, the K-FJS was completed twice by telephone survey for 100 patients. Responsiveness was retrospectively calculated based on a survey of 50 patients at 3 months and 1 year after surgery. Results: The K-FJS exhibited an excellent reliability (Cronbach's α, 0.967; intraclass correlation coefficient, 0.958; 95% confidence interval, 0.930–0.974). The ceiling effect of the K-FJS was 8.7% (n = 13), which was lower than the WOMAC's ceiling effect (10%).There was no floor effect. The correlation coefficients with WOMAC and SF-36 (physical function) were 0.708 and 0.682, respectively, indicating good construct validity. However, its correlation with mental health subscale of SF-36 was low (r = 0.143). At 3 to 12 months after TKA, the standardized response mean (SRM) was 0.67, which was lower than the SRM of WOMAC (1.03) obtained in the same period. The K-FJS demonstrated strong measurement properties in terms of good construct validity and reliability. Conclusions This study suggests that the K-FJS is an excellent instrument that can be used to monitor clinical outcomes after TKA. Using this standardized K-FJS, it would be possible for medical institutions to share more accurate clinical results.

Proximal tibial osteotomy is an effective, well-established treatment for unicompartmental arthritic knee with varus or valgus deformity. Four basic types are commonly described: lateral closing wedge osteotomy, medial open wedge osteotomy, dome osteotomy, and medial opening hemicallotasis. The objective of this procedure is to realign the weight-bearing axis through the knee by redistributing the forces of weight to the less involved compartment of the knee. With thorough preoperative planning and careful selection of patients, optimal outcome can be expected with preservation of the patient's joint. In this article, we reviewed selection of patients, surgical planning, surgical technique, complications, pre- and post-operative change in mechanics, and long term surgical outcome of closing wedge osteotomy. Optimal outcome is expected in patients with young age (younger than 60), stable knee, medially confined osteoarthritis, and good range of motion. According to the literature, average 10-year survival rate is expected to be 60% to 90%. Closing wedge osteotomy allows for rapid bone healing, early weight bearing, rehabilitation, and low rates of correction loss. Surgeons should keep in mind that optimal indication, preoperative planning, and use of safe operative technique are essential to achievement of best results.
Axis, Cervical Vertebra ; Congenital Abnormalities ; Humans ; Joints ; Knee ; Mechanics ; Osteoarthritis* ; Osteotomy* ; Range of Motion, Articular ; Rehabilitation ; Survival Rate ; Tibia* ; Weight-Bearing

Atherosclerosis, which is the most common chronic disease of the coronary artery, constitutes a vascular pathology induced by inflammation and plaque accumulation within arterial vessel walls. Both DNA methylation and histone modifications are epigenetic changes relevant for atherosclerosis. Recent studies have shown that the DNA methylation and histone modification systems are closely interrelated and mechanically dependent on each other.Herein, we explore the functional linkage between these systems, with a particular emphasis on several recent findings suggesting that histone acetylation can help in targeting DNA methylation and that DNA methylation may control gene expression during atherosclerosis.

Background: Patient-reported satisfaction following total knee arthroplasty (TKA) can be affected by various factors. This study aimed to assess patient satisfaction rates and identify factors related to patients, surgery, and postoperative knee motion associated with satisfaction in posterior-stabilized TKA among Asian patients. Methods: A retrospective cross-sectional study was conducted in patients with primary osteoarthritis who underwent TKA and had a follow-up period of over 2 years. Patient satisfaction was measured using a 5-point Likert scale, and the patients were divided into satisfied and dissatisfied groups. The factors potentially affecting satisfaction were collected, including demographics, comorbidities, surgical options, and knee motion. Univariate and multivariate regression analyses were performed. Results: Of the 858 patients included, 784 (91.4%) were satisfied and 74 (8.6%) were dissatisfied. Fixed-bearing implants and higher postoperative knee flexion angles were associated with satisfaction (odds ratio [OR], 2.366; p = 0.001 and OR, 1.045; p < 0.001, respectively), whereas cerebrovascular disease was related to dissatisfaction (OR, 0.403; p = 0.005). The regression model demonstrated moderate predictability (R2 = 0.112). Conclusions Fixed-bearing implants and higher postoperative knee flexion angles were associated with patient satisfaction following TKA, whereas cerebrovascular disease was associated with dissatisfaction. The identification of these factors could help improve surgical outcomes and patient satisfaction following TKA.

Background: Patient-reported satisfaction following total knee arthroplasty (TKA) can be affected by various factors. This study aimed to assess patient satisfaction rates and identify factors related to patients, surgery, and postoperative knee motion associated with satisfaction in posterior-stabilized TKA among Asian patients. Methods: A retrospective cross-sectional study was conducted in patients with primary osteoarthritis who underwent TKA and had a follow-up period of over 2 years. Patient satisfaction was measured using a 5-point Likert scale, and the patients were divided into satisfied and dissatisfied groups. The factors potentially affecting satisfaction were collected, including demographics, comorbidities, surgical options, and knee motion. Univariate and multivariate regression analyses were performed. Results: Of the 858 patients included, 784 (91.4%) were satisfied and 74 (8.6%) were dissatisfied. Fixed-bearing implants and higher postoperative knee flexion angles were associated with satisfaction (odds ratio [OR], 2.366; p = 0.001 and OR, 1.045; p < 0.001, respectively), whereas cerebrovascular disease was related to dissatisfaction (OR, 0.403; p = 0.005). The regression model demonstrated moderate predictability (R2 = 0.112). Conclusions Fixed-bearing implants and higher postoperative knee flexion angles were associated with patient satisfaction following TKA, whereas cerebrovascular disease was associated with dissatisfaction. The identification of these factors could help improve surgical outcomes and patient satisfaction following TKA.

Background: Patient-reported satisfaction following total knee arthroplasty (TKA) can be affected by various factors. This study aimed to assess patient satisfaction rates and identify factors related to patients, surgery, and postoperative knee motion associated with satisfaction in posterior-stabilized TKA among Asian patients. Methods: A retrospective cross-sectional study was conducted in patients with primary osteoarthritis who underwent TKA and had a follow-up period of over 2 years. Patient satisfaction was measured using a 5-point Likert scale, and the patients were divided into satisfied and dissatisfied groups. The factors potentially affecting satisfaction were collected, including demographics, comorbidities, surgical options, and knee motion. Univariate and multivariate regression analyses were performed. Results: Of the 858 patients included, 784 (91.4%) were satisfied and 74 (8.6%) were dissatisfied. Fixed-bearing implants and higher postoperative knee flexion angles were associated with satisfaction (odds ratio [OR], 2.366; p = 0.001 and OR, 1.045; p < 0.001, respectively), whereas cerebrovascular disease was related to dissatisfaction (OR, 0.403; p = 0.005). The regression model demonstrated moderate predictability (R2 = 0.112). Conclusions Fixed-bearing implants and higher postoperative knee flexion angles were associated with patient satisfaction following TKA, whereas cerebrovascular disease was associated with dissatisfaction. The identification of these factors could help improve surgical outcomes and patient satisfaction following TKA.

Background: Nonsteroidal anti-inflammatory drugs (NSAID) are currently among the most prescribed medications worldwide to relieve pain and reduce inflammation, especially in patients suffering osteoarthritis (OA). However, NSAIDs are known to have adverse effects on the gastrointestinal system. If a gastric ulcer occurs, planned OA treatment needs to be changed, incurring additional treatment costs and causing discomfort for both patients and clinicians. Therefore, it is necessary to create a gastric ulcer prediction model that can reflect the detailed health status of each individual and to use it when making treatment plans. Methods: Using sample cohort data from 2008 to 2013 from the National Health Insurance Service in South Korea, we developed a prediction model for NSAID-induced gastric ulcers using machine-learning algorithms and investigated new risk factors associated with medication and comorbidities. Results: The population of the study consisted of 30,808 patients with OA who were treated with NSAIDs between 2008 and 2013. After a 2-year follow-up, these patients were divided into two groups: without gastric ulcer (n=29,579) and with gastric ulcer (n=1,229). Five machine-learning algorithms were used to develop the prediction model, and a gradient boosting machine (GBM) was selected as the model with the best performance (area under the curve, 0.896; 95% confidence interval, 0.883–0.909). The GBM identified 5 medications (loxoprofen, aceclofenac, talniflumate, meloxicam, and dexibuprofen) and 2 comorbidities (acute upper respiratory tract infection [AURI] and gastroesophageal reflux disease) as important features. AURI did not have a dose-response relationship, so it could not be interpreted as a significant risk factor even though it was initially detected as an important feature and improved the prediction performance. Conclusions We obtained a prediction model for NSAID-induced gastric ulcers using the GBM method. Since personal prescription period and the severity of comorbidities were considered numerically, individual patients’ risk could be well reflected. The prediction model showed high performance and interpretability, so it is meaningful to both clinicians and NSAID users.

Background: Little is known about the relationship between implant material and periprosthetic bone mineral density (pBMD) in total knee arthroplasty (TKA). The purpose of this study was to investigate the change in pBMD after TKA and to compare pBMD changes between two different implant materials. Methods: A prospective matched-pair case-control study was conducted on 29 patients who underwent bilateral TKAs. The participants were randomly allocated to undergo cemented TKAs with a titanium nitride (TiN)-coated implant on one knee (TiN group) and a cobalt-chromium (CoCr) implant on the other knee (CoCr group). The pBMD was measured using dual-energy X-ray absorptiometry scans before surgery and at 1 and 2 years after surgery. The results were then compared between the two groups. The pBMDs at longer follow-ups (> 2 years) were estimated using simple radiographs (pBMDe). Results: At 2 years after surgery, the pBMD significantly decreased in both groups at medial metaphysis of the tibia and anterior portion of the distal femur (all p < 0.001). The CoCr group showed a larger decrease in pBMD than did the TiN group in the medial and anterior metaphysis of the proximal tibia (p = 0.003 and p = 0.046, respectively). The pBMDe was significantly higher in the TiN group at the anterior portion of the distal femur 7 years after surgery (p = 0.019). Conclusions The pBMD significantly decreased 2 years after TKA in certain regions regardless of the implant material used. However, the decrease was significantly less in the TiN group in specific regions of the tibia and femur. The TiN implant was beneficial in preserving the periprosthetic bone stock after TKA.

Background: Arthroscopic partial meniscectomy (APM) continues to be the popular treatment for meniscal tears, but recent randomized controlled trials have questioned its efficacy. To provide more evidence-based criteria for patient selection, we undertook this study to identify prognostic factors associated with clinical failure after APM for medial meniscus tears. Methods: Medical records of 160 patients followed up for at least 5 years after APM for medial meniscal tears were retrospectively reviewed. Demographic data (age, sex, and body mass index), radiographic variables (Kellgren-Lawrence [K-L] grade and hip-knee-ankle [HKA] angle), and clinical scores (International Knee Documentation Committee score, Tegner activity scale score, Lysholm score, and Knee injury and Osteoarthritis Outcome Score) were recorded. Clinical failure was defined as the need for an additional surgical procedure (arthroscopy, osteotomy, or arthroplasty) or the presence of intolerable pain. Survivorship analysis with clinical failure as an end point was performed using Kaplan-Meier survival curves. Factors related to clinical failure were analyzed using a Cox proportional hazard model. Cutoff values were determined using areas under receiver operating characteristic (ROC) curves. Radiographic progression of osteoarthritis was analyzed using the chi-square test, and serial changes of clinical scores were analyzed using a linear mixed model. Results: Clinical success rates were 95.7% at 5 years, 75.6% at 10 years, and 46.3% at 15 years. Age, HKA angle, and K-L grade (p = 0.01, p = 0.02, and p = 0.04, respectively) were found to be significant risk factors of clinical failure. Cutoff values at 10 years postoperatively as determined by ROC analysis were 50 years for age (sensitivity = 0.778, 1-specificity = 0.589), grade 2 for K-L grade (sensitivity = 0.778, 1-specificity = 0.109), and 5.5° for HKA angle (sensitivity = 0.667, 1-specificity = 0.258). In patients who had clinical success until 10 years after APM, radiological osteoarthritis progressed gradually. However, the clinical scores of patients who achieved clinical success did not decrease significantly over the 10-year follow-up. Conclusions The poor prognostic factors found to be related to clinical failure after APM for a medial meniscal tear were patient age (≥ 50 years), preoperative K-L grade (≥ grade 2), and preoperative HKA angle (≥ varus 5.5°).