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1.  Continuous Improvements of a Clinical Pathway Increased Its Feasibility and Improved Care Providers' Perception in TKA 
Knee Surgery & Related Research  2014;26(4):199-206.
Purpose
We aimed to determine 1) whether dropout rate decreased and 2) whether health care providers' perceptions were changed with continued improvements of contents of clinical pathway (CP) for total knee arthroplasty (TKA).
Materials and Methods
This retrospective study included two separate analyses of patients and health care providers. In the analysis of patients, dropout rates and reasons were evaluated in two cohorts of patients who underwent TKA with CP applied at two different time periods (384 patients from 2009 to 2010 and 242 patients from 2012 to 2013). Contents of CP were continuously improved during the 3-year interval. Self-administered questionnaire surveys targeted to health care providers were carried out twice (2010 and 2013) and compared.
Results
Dropout rate decreased from 19.1% in the first time period to 10.4% in the second time period. Although overall satisfaction of care providers was high at both time-points, doctors had more favorable perceptions than nurses; most positive changes of perception were noted in nurses. The health care providers' perceptions for potential concerns of CP were improved while the perceptions for potential benefits and satisfaction were maintained.
Conclusions
Continuously improved CP has increased feasibility for TKA patients and reduced health care providers' concern about its value. We propose that CP can be implemented and actively used to improve the outcomes and efficacy of patient care for TKA, regardless of the rotation of care providers.
doi:10.5792/ksrr.2014.26.4.199
PMCID: PMC4258486  PMID: 25505701
Knee; Arthroplasty; Clinical pathways; Health care providers
2.  Clinicopathologic factors influencing the accuracy of EUS for superficial esophageal carcinoma 
AIM: To identify clinicopathologic factors influencing the accuracy of a high-frequency catheter probe endoscopic ultrasonography (EUS) for superficial esophageal carcinomas (SECs).
METHODS: A total of 126 patients with endoscopically suspected SEC, who underwent EUS and curative treatment at Pusan National University Hospital during 2005-2013, were enrolled. We reviewed the medical records of the 126 patients and compared EUS findings with histopathologic results according to clinicopathologic factors.
RESULTS: A total of 114 lesions in 113 patients were included in the final analysis. The EUS assessment of tumor invasion depth was accurate in 78.9% (90/114) patients. Accuracy did not differ according to histologic type, tumor differentiation, tumor location, or macroscopic shape. However, accuracy significantly decreased for tumors ≥ 3 cm in size (P = 0.002). Overestimation and underestimation of the invasion depth occurred for 11 (9.6%) and 13 lesions (11.4%), respectively. In multivariate analyses, tumor size ≥ 3 cm was the only factor significantly associated with EUS accuracy (P = 0.031), and was specifically associated with the underestimation of invasion depth.
CONCLUSION: EUS using a high-frequency catheter probe generally provides highly accurate assessments of SEC invasion depth, but its accuracy decreases for tumors ≥ 3 cm.
doi:10.3748/wjg.v20.i20.6322
PMCID: PMC4033471  PMID: 24876754
Esophageal cancer; Endoscopic ultrasonography; Accuracy
3.  Special Considerations for TKA in Asian Patients: Editorial Comment 
doi:10.1007/s11999-013-2883-0
PMCID: PMC3613552  PMID: 23456191
4.  Prediction of Chronicity of Anterior Cruciate Ligament Tear Using MRI Findings 
Clinics in Orthopedic Surgery  2013;5(1):19-25.
Background
The estimation of anterior cruciate ligament (ACL) tear is required in certain cases involving legal and financial administration, such as the worker's compensation and/or insurance. The aim of this study is to propose and evaluate a quantitative evaluation instrument to estimate the chronicity of the ACL tear, based on the four magnetic resonance imaging (MRI) findings.
Methods
One hundred and fifty one cases of complete ACL tear confirmed by arthroscopy were divided into 4 groups according to the time from ACL injury to MRI acquisition: acute (< 6 weeks), subacute (6 weeks to 3 months), intermediate (3 months to 1 year), and chronic (> 1 year). The four MRI findings including ACL morphology, joint effusion, posterior cruciate ligament angle, and bone bruise were analyzed for temporal changes among the 4 groups. Binary logistic regression equations were formulated using the MRI findings to estimate the chronicity of ACL tear in a quantitative manner, and the accuracy of the formulated regression equations was evaluated.
Results
The four MRI findings showed substantial temporal correlation with the time-limits of ACL injury to be included in the estimation model. Three predictive binary logistic equations estimated the probability of the ACL injury for the three cutoff time-limits of 6 weeks, 3 months, and 1 year with accuracies of 82.1%, 89.4%, and 89.4%, respectively.
Conclusions
A series of predictive logistic equations were formulated to estimate the chronicity of ACL tear using 4 MRI findings with chronological significance.
doi:10.4055/cios.2013.5.1.19
PMCID: PMC3582867  PMID: 23467216
Anterior cruciate ligament; Chronicity; Magnetic resonance imaging; Predictive model
5.  The EC50 of remifentanil to minimize the cardiovascular changes during head holder pinning in neurosurgery 
Korean Journal of Anesthesiology  2012;63(4):327-333.
Background
During neuroanesthesia, head holder pinning commonly results in sympathetic stimulation manifested by hemodynamic changes, such as increased heart rate and arterial blood pressure. Remifentanil has been used successfully to control acute autonomic responses during neurosurgical procedures. The objective of this study was to determine effect-site concentration of remifentanil for suppressing the hemodynamic response to head holder pinning with the probability of 50% (EC50).
Methods
Forty-one ASA physical status I or II patients, between the ages of 20-70, who were scheduled for neurosurgery were recruited into this study. After arrival in the operating room, standard monitoring was applied throughout the study, which included a bispectral index monitor. Both propofol and remifentanil were administered by Target-control infusion device. The Dixon "up-and-down" sequential allocation method was used to determine the EC50 of remifentanil.
Results
The EC50 of remifentanil was 2.19 ± 0.76 ng/ml by the turning point estimate (TPE). In probit analysis, EC50 was 2.42 ng/ml (95% CI : -0.62-4.66) and EC95 was 5.70 ng/ml (95% CI : 4.02-67.53). The EC50 estimator comes from isotonic regression is 2.90 ng/ml (95% CI : 1.78-3.65). The EC95 estimator comes from isotonic regression is 4.28 ng/ml (95% CI : 3.85-4.41).
Conclusions
This study showed that EC50 of remifentanil was 2.19 ± 0.76 ng/ml by TPE. EC50 was 2.42 ng/ml (95% CI -0.62-4.66) in probit analysis, as back up analysis. The EC50 estimator comes from isotonic regression is 2.90 ng/ml (95% CI : 1.78-3.65).
doi:10.4097/kjae.2012.63.4.327
PMCID: PMC3483491  PMID: 23115685
Hemodynamics; Neurosurgery; Propofol; Remifentanil
6.  Causes, Risk Factors, and Trends in Failures After TKA in Korea Over the Past 5 Years: A Multicenter Study 
Background
Failure after total knee arthroplasty (TKA) may be related to emerging technologies, surgical techniques, and changing patient demographics. Over the past decade, TKA use in Korea has increased substantially, and demographic trends have diverged from those of Western countries, but failure mechanisms in Korea have not been well studied.
Questions/purposes
We determined the causes of failure after TKA, the risk factors for failure, and the trends in revision TKAs in Korea over the last 5 years.
Methods
We retrospectively reviewed 634 revision TKAs and 20,234 primary TKAs performed at 19 institutes affiliated with the Kleos Korea Research Group from 2008 to 2012. We recorded the causes of failure after TKA using 11 complications from the standardized complication list of The Knee Society, patient demographics, information on index and revision of TKAs, and indications for index TKA. The influences of patient demographics and indications for index TKA on the risk of TKA failure were evaluated using multivariate regression analysis. The trends in revision procedures and demographic features of the patients undergoing revision TKA over the last 5 years were assessed.
Results
The most common cumulative cause of TKA failure was infection (38%) followed by loosening (33%), wear (13%), instability (7%), and stiffness (3%). However, the incidence of infections has declined over the past 5 years, whereas that of loosening has increased and exceeds that of infection in the more recent 3 years. Young age (odds ratio [OR] per 10 years of age increase, 0.41; 95% confidence interval [CI], 0.37–0.49) and male sex (OR, 1.88; 95% CI, 1.42–2.49) were associated with an increased risk of failure. The percentage of revision TKAs in all primary and revision TKAs remained at approximately 3%, but the annual numbers of revision TKAs in the more recent 3 years increased from that of 2008 by more than 23%.
Conclusions
Despite a recent remarkable increase in TKA use and differences in demographic features, the causes and risk factors for failures in Korea were similar to those of Western countries. Infection was the most common cause of failure, but loosening has emerged as the most common cause in more recent years, which would prompt us to scrutinize the cause and solution to reduce it.
Level of Evidence
Level IV, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.
doi:10.1007/s11999-013-3252-8
PMCID: PMC3889422  PMID: 23982406
7.  Differences in Anatomy and Kinematics in Asian and Caucasian TKA Patients: Influence on Implant Positioning and Subsequent Loading Conditions in Mobile Bearing Knees 
BioMed Research International  2014;2014:612838.
The objective of our study was to determine the mechanical stress conditions under tibiofemoral loading with an overlay of knee kinematics in deep flexion on two different mobile bearing designs in comparison to in vivo failure modes. This study investigates the seldom but severe complication of fatigue failure of polyethylene components at mobile bearing total knee arthroplasty designs. Assuming a combination of a floor-based lifestyle and tibial malrotation as a possible reason for a higher failure rate in Asian countries we developed a simplified finite element model considering a tibiofemoral roll-back angle of 22° and the range of rotational motion of a clinically established floating platform design (e.motion FP) at a knee flexion angle of 120° in order to compare our results to failure modes found in retrieved implants. Compared to the failure mode observed in the clinical retrievals the locations of the occurring stress maxima as well as the tensile stress distribution show analogies. From our observations, we conclude that the newly introduced finite element model with an overlay of deep knee flexion (lateral roll-back) and considerable internally rotated tibia implant positioning is an appropriate analysis for knee design optimizations and a suitable method to predict clinical failure modes.
doi:10.1155/2014/612838
PMCID: PMC4258361  PMID: 25538943
8.  Coronal Limb Alignment and Indications for High Tibial Osteotomy in Patients Undergoing Revision ACL Reconstruction 
Background
Failed ACL reconstruction frequently is accompanied by irreparable medial meniscal tear and/or visible osteoarthritis (OA) in the medial tibiofemoral joint. Thus, assessment for the presence of varus malalignment is important in caring for patients in whom revision ACL reconstruction is considered.
Questions/purposes
We determined whether patients undergoing revision ACL reconstruction (1) have more frequent varus malalignment coupled with more severe degrees of medial meniscal injury and/or medial tibiofemoral OA, and (2) would meet potential indications for high tibial osteotomy more frequently than patients undergoing primary ACL reconstruction.
Methods
We compared 58 patients undergoing revision ACL reconstruction and 116 patients undergoing primary ACL reconstruction. The mechanical tibiofemoral angle and the weight loading line (%) of the knee were measured. Additionally, radiographic degrees of OA in the tibiofemoral joints, and meniscal conditions were assessed. Then, proportions of potential candidates for high tibial osteotomy between the two groups were compared based on the following indications: (1) weight loading line less than 5%, (2) weight loading line less than 25% and medial tibiofemoral OA Kellgren-Lawrence Grade 3 or greater, or (3) weight loading line less than 25% and Kellgren-Lawrence Grade 2 medial tibiofemoral OA plus subtotal or total medial meniscectomy status.
Results
The revision ACL reconstruction group had more frequent varus malalignment in terms of proportion of knees with more varus mechanical tibiofemoral angle than varus 5° (19% versus 8%, p = 0.029) and knees with weight loading line less than 25% (22% versus 9%, p = 0.011). This group also had more frequent high-grade injury of the medial meniscus (34% versus 16%, p = 0.007) and tended to have more frequent higher-grade radiographic OA at the medial tibiofemoral joint (19% versus 9%, p = 0.076). The percentage of patients meeting potential indications for high tibial osteotomy was greater in this group (14% versus 2%, p = 0.003).
Conclusions
We found that many patients undergoing revision ACL surgery may be reasonable candidates for concurrent high tibial osteotomy to address concomitant alignment and OA issues in the medial compartment. However, whether that additional intervention is offset by added risk and morbidity should be the focus of a future study, as it cannot be answered by a study of this design.
Level of Evidence
Level III, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.
doi:10.1007/s11999-013-3185-2
PMCID: PMC3792260  PMID: 23877556
9.  How Useful Is MRI in Diagnosing Isolated Bundle ACL Injuries? 
Background
Selective bundle anterior cruciate ligament (ACL) reconstruction and/or remnant ACL preservation may be reasonable options for some patients. However, the frequency of isolated anteromedial (AM) or posterolateral (PL) bundle injuries in patients undergoing ACL reconstruction is unknown, and the value of MRI for prediction of this injury pattern is likewise unknown.
Questions/purposes
We sought to determine (1) the proportion of knees with an intact AM or PL bundle in patients undergoing ACL reconstruction; (2) whether MRI predicted the bundle conditions seen at the time of surgery; and (3) whether the accuracy of the MRI prediction was affected by the timing of MRI after injury.
Methods
During primary ACL reconstructions of 156 knees, conditions of AM and PL bundles were separately examined and classified into three categories: (1) completely torn; (2) attenuated; and (3) intact. Then, the bundles were assessed by blinded observers on MRI and classified into the corresponding three categories for 77 patients who had an MRI at our institution using a standard protocol. Diagnostic accuracy of MRI was computed, and the early MRI group (≤ 6 weeks from injury to MRI acquisition) was compared with the late MRI group (> 6 weeks).
Results
Only 11 (7%) of the 156 knees we treated had an intact AM (one knee) or PL bundle (10 knees). Another 55 knees (35%) had a structurally continuous but attenuated AM or PL bundle. The overall diagnostic accuracy of MRI was 83%; accuracy was better for the AM bundle than the PL bundle (91% versus 78%; p = 0.026). MR prediction was less accurate in the early MRI group, particularly for PL bundle injury.
Conclusions
An isolated bundle tear is uncommon in patients with ACL tears undergoing reconstruction. MRI can help surgeons predict bundle injury pattern with satisfactory precision, but caution should be used in predicting PL bundle injury using MRI with early acquisition time from injury.
Level of Evidence
Level III, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.
doi:10.1007/s11999-013-3055-y
PMCID: PMC3773164  PMID: 23661302
10.  Prevalence of Osteoporosis in Female Patients with Advanced Knee Osteoarthritis Undergoing Total Knee Arthroplasty 
Journal of Korean Medical Science  2014;29(10):1425-1431.
This study sought to demonstrate bone mineral density (BMD) conditions in elderly female patients with knee osteoarthritis (OA) undergoing total knee arthroplasty (TKA). In addition, we sought to determine whether their BMD conditions differ from those of community-based females without knee OA. Finally we sought to determine whether clinical statuses are related to BMD in the knee OA patients. BMD conditions in 347 female patients undergoing TKA and 273 community-based females were evaluated. Additionally, comparative analyses of BMD between age and body mass index-matched knee OA groups (n=212) and the control groups (n=212) were performed. In the pre-matched knee OA group, regression analyses were performed to determine whether preoperative clinical statuses were related to BMD. Considerable prevalence of coexistent osteoporosis (31%) was found in the pre-matched knee OA patients undergoing TKA. We found no significant differences of the BMD T-scores and the prevalence of osteoporosis between the age and body mass index-matched knee OA and control groups. In the pre-matched knee OA patients, poorer preoperative clinical scores were related to poorer BMD T-scores in the proximal femur and/or lumbar spine. Our study suggests that more attention should be paid to identify and treat osteoporosis in elderly female patients with advanced knee OA undergoing TKA.
Graphical Abstract
doi:10.3346/jkms.2014.29.10.1425
PMCID: PMC4214945  PMID: 25368498
Bone Density; Osteoporosis; Female Knee Osteoarthritis Patient; Arthroplasty; Knee
11.  Preemptive Low-dose Dexamethasone Reduces Postoperative Emesis and Pain After TKA: A Randomized Controlled Study 
Background
Dexamethasone is a potent analgesic and antiemetic. However, the benefit of dexamethasone after TKA is unclear, as is the efficacy in a current multimodal regime.
Questions/purposes
We determined (1) whether the addition of dexamethasone to a protocol including ramosetron further reduces postoperative emesis compared with ramosetron alone; (2) whether it reduces postoperative pain; and (3) whether it increases the risk for wound complications in a current multimodal regime after TKA.
Methods
We randomized 269 patients undergoing TKAs to receive dexamethasone (10 mg) 1 hour before surgery and ramosetron immediately after surgery (Dexa-Ra group, n = 135), or ramosetron alone (Ra group, n = 134). We recorded the incidence of postoperative nausea and vomiting (PONV), severity of nausea, incidence of antiemetic requirement, complete response, pain level, and opioid consumption. Patients were assessed 0 to 6, 6 to 24, 24 to 48, and 48 to 72 hours postoperatively. In addition, patients were evaluated for wound complications and periprosthetic joint infections at a minimum of 1 year after surgery.
Results
The Dexa-Ra group had a lower incidence of PONV during the entire 72-hour evaluation period and experienced less severe nausea for the first 6 hours after TKA, although not between 6 to 72 hours. Overall use of a rescue antiemetic was less frequent, and complete response was more frequent in the Dexa-Ra group. Patients in the Dexa-Ra group experienced lower pain and consumed less opioids during the 6- to 24-hour period and during the overall study period. No differences were found in wound complications between the groups, and each group had one case of periprosthetic joint infection.
Conclusions
Patients who received prophylactic dexamethasone in addition to ramosetron had reduced postoperative emesis and pain without increased risks for wound complications, compared with patients who received ramosetron alone in patients managed using a multimodal regimen after TKA.
Level of Evidence
Level I, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.
doi:10.1007/s11999-013-3032-5
PMCID: PMC3734432  PMID: 23645340
12.  Evaluation of Femoral Neck Bone Mineral Density and Radiographic Hand and Knee Osteoarthritis in a Korean Elderly Population 
Clinics in Orthopedic Surgery  2014;6(3):343-349.
Background
Reports on the relationship between osteoporosis and osteoarthritis (OA) have tended to disagree, especially in non-weight bearing joints such as the hand joints. We aimed to investigate the relationship between bone mineral density (BMD) and hand and knee OA in a general Korean elderly population.
Methods
We evaluated femur neck BMD and the hand and knee radiographs of 143 men and 123 women over 65 years of age who participated in a population-based cohort study. The Kellgren-Lawrence criteria for grading OA were implemented, and grade 2 or higher were categorized as radiographic OA. BMD was compared according to the existence of radiographic OA in the hand and knee using analysis of covariance, and correlation analyses were performed to explore the relationship between BMD and radiographic OA grade.
Results
After controlling for age and body mass index, there was no significant difference in BMD between participants with and without hand OA (p = 0.717 in male and p = 0.862 in female), between those with and without knee OA (p = 0.974 in male and p = 0.563 in female), and between those with only hand OA and those with only knee OA (p = 0.920 in male and p = 0.961 in female). Furthermore, there was no significant correlation between BMD and the radiographic OA grade of the hands (p = 0.182 in male and p = 0.897 in female) and knees (p = 0.245 in male and p = 0.098 in female).
Conclusions
In our cohort of the general Korean elderly population, no association was found between osteoporosis and OA, regardless of the weight bearing status of the joints.
doi:10.4055/cios.2014.6.3.343
PMCID: PMC4143524  PMID: 25177462
Osteoporosis; Osteoarthritis; Weight bearing; Bone mineral density; Korean population
13.  Activity levels and participation in physical activities by Korean patients following total knee arthroplasty 
Background
The objectives of this study were to describe changes in physical activity profiles of Korean patients after TKA and to determine whether the postoperative physical activity level is influenced by patient socio-demographic factors and postoperative functional outcomes. We also sought to determine whether regular postoperative physical activity is associated with greater patient satisfaction after TKA.
Methods
This observational study included 369 patients. Physical activity profiles before and after TKA were evaluated using a questionnaire that contained the UCLA activity scale and types of sports activities. The associations of socio-demographic features and postoperative functional outcomes with the physical activity levels were assessed using subgroup comparisons and partial correlation analyses. In addition, the effects of regular physical activity on patient satisfaction with replaced knees were evaluated using subgroup comparisons.
Results
Walking, swimming and bicycling were the three most common sports activities both before and after TKA. After TKA, the mean activity level remained similar (UCLA score = 4.5 before TKA vs. 4.8 after TKA); however, the frequency of moderate activity levels (UCLA scale, 4-6) and moderate types of physical activities increased. Patients with higher postoperative function scores reported higher postoperative activity levels, but socio-demographic factors were not associated with activity level. Regular physical activity was associated with greater patient satisfaction.
Conclusions
This study provides valuable information about realistic expectations for physical activity after TKA. Regular participation in physical activity should be encouraged to improve patient satisfaction.
doi:10.1186/1471-2474-15-240
PMCID: PMC4108970  PMID: 25030804
Total knee arthroplasty; Physical activity; Patient factor; Satisfaction
14.  Can magnetic resonance imaging findings predict the degree of knee joint laxity in patients undergoing anterior cruciate ligament reconstruction? 
Background
The present study was performed to determine whether MRI findings can predict the degree of knee joint laxity in patients undergoing ACL reconstruction and whether the accuracy of the prediction is affected by the MRI acquisition time.
Methods
We assessed prospectively collected data of 154 knees with ACL tears. The presence or absence of four primary findings of ACL tears, i.e., nonvisualization, discontinuity, abnormal signal intensity, and abnormal shape of the ACL, and five secondary findings, i.e., anterior translation of the tibia relative to the femur (≥7 mm), posterior cruciate ligament angle (<105°), bone contusion, Segond fracture, and the deep sulcus sign, were determined. Knee joint laxity was assessed using the Lachman and pivot shift tests. The associations between MRI findings and clinically assessed knee joint laxity were analyzed and compared between subgroups (≤3 months from injury to MRI, 89 knees; >3 months, 65 knees).
Results
Nonvisualization was related to the results of the Lachman test [Odds ratio (OR), 2.6; 95% confidence interval (CI), 1.2–5.5]. Anterior translation of the tibia relative to the femur was related to the results of the pivot shift test (OR, 3.8; 95% CI, 1.6–9.4). In subgroup comparisons of the early and late MRI groups, anterior translation of the tibia relative to the femur was related to the results of the pivot shift test in the early MRI group (OR, 4.5; 95% CI, 1.4–14.4). In contrast, no MRI findings had statistically significant relationships with physical findings in the late MRI group.
Conclusions
Our study indicates that MRI findings may have some usefulness for predicting the grade of knee laxity in patients with symptomatic ACL injury, but its value is limited, especially in patients with a longer time interval between injury and the performance of MRI.
doi:10.1186/1471-2474-15-214
PMCID: PMC4081463  PMID: 24950603
Anterior Cruciate Ligament Injury; Magnetic Resonance Imaging; Prediction of laxity
15.  Must Bilaterality Be Considered In Statistical Analyses of Total Knee Arthroplasty? 
Background
In studies of TKA, treating each knee as an independent case in patients with bilateral TKAs can lead to errors, because patients with bilateral and unilateral TKAs may achieve different levels of function and because the assumption of statistical independence is violated.
Questions/purposes
We determined whether (1) patients undergoing bilateral TKAs have different demographics and preoperative and postoperative function from those undergoing unilateral TKAs, and (2) means, SEs, and p values change substantially based on how the two cases of bilateral TKAs are treated in statistical analyses.
Methods
We retrospectively compared 513 patients undergoing unilateral TKAs and 602 patients undergoing bilateral TKAs regarding demographics (age, gender, BMI), preoperative and 1-year postoperative function (motion arc, American Knee Society score, patellofemoral score, WOMACTM, SF-36). Each case of a bilateral TKA was treated as independent in the reference analyses. Then changes of mean, SEs, and p values were compared with those of the reference method when three other methods of analysis were used: using mean values of both knees, randomly selecting one side, and using a generalized estimating equation.
Results
Patients undergoing bilateral TKAs had higher female predominance (95% versus 90%) and BMI (27.4 versus 26.1 kg/m2) than those undergoing unilateral TKAs. Although patients undergoing bilateral TKAs had worse preoperative function, they achieved comparable function at 1 year. The mean values did not differ considerably depending on the four methods. The SEs and p values of the reference method were generally the smallest, but the differences appeared negligible.
Conclusions
Our analyses suggest bilaterality can be ignored in the analysis of TKA, since postoperative function is comparable between unilateral and bilateral TKAs and the theoretical errors in statistical analysis had little effect on the results.
doi:10.1007/s11999-013-2810-4
PMCID: PMC3706661  PMID: 23371562
16.  Development and Validation of a New Evaluation System for Patients With a Floor-based Lifestyle: The Korean Knee Score 
Background
Patients’ perspectives on functioning and health have been increasingly recognized as a crucial aspect of health care, leading to the use of patient-reported instruments for outcome assessment. However, available instruments for total knee arthroplasty do not reflect the floor-based lifestyle with high knee flexion of eastern Asia.
Questions/purposes
We therefore (1) describe a novel patient-generated knee evaluation instrument, the Korean knee score (KKS), to reflect floor-based lifestyles with high knee flexion that included questions regarding health-related quality of life; (2) determined the reliability of the questionnaire; and (3) performed limited validation studies.
Methods
The KKS was developed by a committee of 10 experts from 10 institutes nationwide. The development procedure comprised a development phase for generation of the questionnaire and a testing phase for assessment of measurement properties: reliability, validity, and responsiveness. A total of 634 patients participated in this test survey.
Results
The KKS exhibited an intraclass correlation coefficient of 0.931 and internal consistency (Cronbach’s α = 0.973). The absence of a ceiling or floor effect suggested content validity. The correlation coefficient with Knee Society score (knee score, function score) and Oxford knee score was 0.599, 0.690, and 0.871, respectively, suggesting construct validity. Correlation with concurrent measures of physical function from the SF-36 ranged from 0.549 to 0.719 and those of mental function from 0.407 to 0.428. Responsiveness was evident with a standardized response mean of 0.74.
Conclusions
The KKS is a reliable and responsive instrument for assessing osteoarthritis. The limited validation studies suggest it is an appropriate evaluation instrument for patients with osteoarthritis and a floor-based lifestyle.
doi:10.1007/s11999-012-2726-4
PMCID: PMC3613544  PMID: 23229425
17.  Trends in Use of Total Knee Arthroplasty in Korea From 2001 to 2010 
Background
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.
Questions/purposes
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.
Methods
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.
Results
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.
Conclusions
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.
doi:10.1007/s11999-012-2622-y
PMCID: PMC3613551  PMID: 23054516
18.  Femoral Lateral Bowing and Varus Condylar Orientation Are Prevalent and Affect Axial Alignment of TKA in Koreans 
Background
Coronal alignment is considered key to the function and longevity of a TKA. However, most studies do not consider femoral and tibial anatomical features such as lateral femoral bowing and the effects of these features and subsequent alignment on function after TKA are unclear.
Questions/purposes
We therefore determined (1) the prevalence of lateral femoral bowing, varus femoral condylar orientation, and severe tibia plateau inclination in female Koreans undergoing TKA; (2) whether postoperative alignments are affected by these anatomical features and improved by the use of navigation; and (3) whether postoperative coronal alignments are associated with function.
Methods
We measured alignment in 367 knees that underwent TKA and 60 sex- and age-matched normal knees (control group). We determined patterns and degrees of femoral bowing angle, femoral condylar orientation, and tibial plateau inclination on preoperative full-limb radiographs. Postoperatively, coronal alignment of limbs and of femoral and tibial components was measured. We compared American Knee Society scores, WOMAC scores, and SF-36 scores in aligned knees and outliers (beyond ± 3° or ± 2°) at 1 year.
Results
The prevalence of lateral femoral bowing was 88% in the TKA group and 77% in the control group. Mean femoral condylar orientation angle was varus 2.6° in the TKA group and valgus 1.1° in the control group, and mean tibial plateau inclination was varus 8.3° in the TKA group and varus 5.4° in the control group. Femoral lateral bowing and varus femoral condylar orientation were associated with postoperative alignments. Several clinical outcome scales were inferior in the outliers in mechanical tibiofemoral angle, anatomical tibiofemoral angle, and tibial coronal alignment but not in femoral coronal alignment outliers.
Conclusions
Lateral femoral bowing, varus condylar orientation, and severe varus inclination of the tibia plateau should be considered when performing TKA in Korean patients or patients with otherwise similar anatomical features.
doi:10.1007/s11999-012-2618-7
PMCID: PMC3613555  PMID: 23011845
19.  Efficacy and Safety of Aceclofenac Controlled Release in Patients with Knee Osteoarthritis: A 4-week, Multicenter, Randomized, Comparative Clinical Study 
Purpose
To evaluate the analgesic effect, efficacy and safety of aceclofenac controlled release (CR) in patients with chronic knee osteoarthritis (OA).
Materials and Methods
A total of 125 subjects with chronic knee OA were randomly divided into two groups: one group (n=62) was administered aceclofenac CR once daily and the other (n=63), aceclofenac immediate release (IR) twice a day for 4 weeks. A 100-mm visual analogue scale (VAS), Knee injury and Osteoarthritis Outcome Score (KOOS) and range of motoin (ROM) were evaluated as the outcome measures. To evaluate the safety of the drug, adverse events, vital signs, physical examination findings, clinical laboratory values and electrocardiographic findings were evaluated.
Results
The VAS, KOOS and ROM were improved after 4 weeks of administration in both groups, but the differences between the two groups were not statistically significant. Significant differences between the two groups were not shown in the evaluation of the adverse events, vital sign, physical examination results, clinical laboratory values, and electrocardiography.
Conclusions
The aceclofenac CR and aceclofenac IR were equally effective in patients with chronic knee OA and the clinical trial results didn't show any significant difference in safety. The new aceclofenac CR formulation was found to be effective and safe with the practical advantage of once daily administration.
doi:10.5792/ksrr.2014.26.1.33
PMCID: PMC3953523  PMID: 24639945
Knee; Osteoarthritis; Aceclofenac; Controlled-release preparations
20.  Oxycodone vs. Fentanyl Patient-Controlled Analgesia after Laparoscopic Cholecystectomy 
Objectives Oxycodone is semi-synthetic opioid, oral and parenteral preparations have been widely used for acute and chronic pain. The aim of this study was to assess the efficacy and side effects of oxycodone and fentanyl in patient controlled analgesia (PCA) after laparoscopic cholecystectomy.
Methods A prospective, randomized, double-blind study was conducted. 81 patients were randomly divided into two groups; fentanyl (10 mcg fentanyl and 1.5 mg ketorolac) and oxycodone group (1 mg oxycodone and 1.5 mg ketorolac). After the operation, a blinded observer assessed pain using a numerical rating scale (NRS), infused PCA dose, side effects, sedation levels, and satisfaction.
Results Cumulative PCA dose of oxycodone group at 48 h (31.4 ± 16.0 ml) was significantly less than that of fentanyl group (43.8 ± 23.1 ml, P = 0.009). Oxycodone group showed more nausea at 6 - 24 h after the operation (P = 0.001), but there was no difference in satisfaction score (P = 0.073). There were no significant differences in other side effects, sedation and NRS scores between two groups.
Conclusion Oxycodone showed comparable effects for pain relief compared to fentanyl in spite of less cumulative PCA dose. Based on these results, we could conclude that oxycodone may be useful as an alternative to fentanyl for PCA after laparoscopic cholecystectomy.
doi:10.7150/ijms.8331
PMCID: PMC4025163  PMID: 24843313
Fentanyl; Laparoscopic cholecystectomy surgery; Oxycodone; Patient-controlled analgesia; Postoperative pain.
21.  Cytokine signaling-1 suppressor is inducible by IL-1beta and inhibits the catabolic effects of IL-1beta in chondrocytes: its implication in the paradoxical joint-protective role of IL-1beta 
Arthritis Research & Therapy  2013;15(6):R191.
Introduction
Although IL-1β is believed to be crucial in the pathogenesis of osteoarthritis (OA), the IL-1β blockade brings no therapeutic benefit in human OA and results in OA aggravation in several animal models. We explored the role of a cytokine signaling 1 (SOCS1) suppressor as a regulatory modulator of IL-1β signaling in chondrocytes.
Methods
Cartilage samples were obtained from patients with knee OA and those without OA who underwent surgery for femur-neck fracture. SOCS1 expression in cartilage was assessed with immunohistochemistry. IL-1β-induced SOCS1 expression in chondrocytes was analyzed with quantitative polymerase chain reaction and immunoblot. The effect of SOCS1 on IL-1β signaling pathways and the synthesis of matrix metalloproteinases (MMPs) and aggrecanase-1 was investigated in SOCS1-overexpressing or -knockdown chondrocytes.
Results
SOCS1 expression was significantly increased in OA cartilage, especially in areas of severe damage (P < 0.01). IL-1β stimulated SOCS1 mRNA expression in a dose-dependent pattern (P < 0.01). The IL-1β-induced production of MMP-1, MMP-3, MMP-13, and ADAMTS-4 (aggrecanase-1, a disintegrin and metalloproteinase with thrombospondin motifs 4) was affected by SOCS1 overexpression or knockdown in both SW1353 cells and primary human articular chondrocytes (all P values < 0.05). The inhibitory effects of SOCS1 were mediated by blocking p38, c-Jun N-terminal kinase (JNK), and nuclear factor κB (NF-κB) activation, and by downregulating transforming growth factor-β-activated kinase 1 (TAK1) expression.
Conclusions
Our results show that SOCS1 is induced by IL1-β in OA chondrocytes and suppresses the IL-1β-induced synthesis of matrix-degrading enzymes by inhibiting IL-1β signaling at multiple levels. It suggests that the IL-1β-inducible SOCS1 acts as a negative regulator of the IL-1β response in OA cartilage.
doi:10.1186/ar4381
PMCID: PMC3979110  PMID: 24238405
22.  How Much Are Upper or Lower Extremity Disabilities Associated with General Health Status in the Elderly? 
Background
Musculoskeletal complaints influence general health status, but the relative contribution of concurrent upper and lower extremity disabilities on patient perceptions of general health is unclear.
Questions/Purposes
We evaluated whether two regional instruments (DASH and WOMAC) reflect a patient’s perception of general health measured using the SF-36 and determined whether general health components are explained by upper and lower extremity disabilities.
Methods
We recruited 272 randomly chosen participants 65 years or older without a history of surgery for musculoskeletal disease or trauma who participated in the Korean Longitudinal Study on Health and Aging. Upper extremity disability was determined with the DASH score and lower extremity disability with the WOMAC; as a measure of general health, we obtained SF-36 scores. Multivariate regression modeling was used to assess the relative contributions made by upper and lower extremity disabilities to general health.
Results
The DASH and WOMAC each was correlated with the physical component summary (PCS) scale and with the mental component summary (MCS) scale to differing extents. Multivariate regression analyses revealed that WOMAC alone, DASH alone, and WOMAC and DASH accounted for 24%, 19%, and 26% of the variance in the PCS scale. However, only the DASH was associated with the MCS scale but accounted for only 2% of the variance.
Conclusions
We found that in a community-based elderly population, perceived general physical health is associated with upper and lower extremity disabilities, whereas perceived general mental health is associated with only upper extremity disabilities, but to a small extent.
Level of Evidence
Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.
doi:10.1007/s11999-012-2417-1
PMCID: PMC3462850  PMID: 22689096
23.  The Impact of High Sensitivity C-Reactive Protein Level on Coronary Artery Spasm as Assessed by Intracoronary Acetylcholine Provocation Test 
Yonsei Medical Journal  2013;54(6):1299-1304.
Purpose
High sensitive C-reactive protein (hs CRP) is well known as a strong risk factor of cardiovascular disease (CVD). The aim of this study is to evaluate the impact of elevated hs CRP on coronary artery spasm (CAS) as assessed by intracoronary acetylcholine (ACh) provocation test.
Materials and Methods
A total of 1729 consecutive patients without significant CVD who underwent coronary angiography and intracoronary ACh test between November 2004 and August 2010 were analyzed. The patients were divided into five groups according to quintiles of hs CRP levels.
Results
At baseline, the prevalence of elderly, hypertension, diabetes mellitus, current smoking, and lipid levels were higher in patients with higher hs CRP. During ACh test, the incidences of significant CAS, ischemic electrocardiography (EKG) change, multivessel, and diffuse CAS were higher in patients with higher hs CRP. Multivariate analysis showed that the old age (OR=1.01, CI; 1.0-1.02, p=0.0226), myocardial bridge (OR=3.34, CI; 2.16-5.17, p<0.001), and highest quintile hs CRP (OR=1.54, CI; 1.12-2.18, p=0.008) were independent predictors of ACh induced CAS. However, there was no difference in clinical outcomes up to 12 months.
Conclusion
In conclusion, higher hs CRP was associated with higher incidence of CAS, worse angiographic characteristics and ischemic EKG change, but was not associated with clinical outcomes.
doi:10.3349/ymj.2013.54.6.1299
PMCID: PMC3809884  PMID: 24142631
C-reactive protein; acetylcholine; coronary artery spasm
24.  Does Ramosetron Reduce Postoperative Emesis and Pain after TKA? 
Background
Current pain management protocols involving many anesthetic and analgesic drugs reportedly provide adequate analgesia after TKA. However, control of emetic events associated with the drugs used in current multimodal pain management remains challenging.
Questions/purposes
We determined (1) whether ramosetron prophylaxis reduces postoperative emetic events; and (2) whether it influences pain levels and opioid consumption in patients managed with a current multimodal pain management protocol after TKA.
Methods
We randomized 119 patients undergoing TKA to receive either ramosetron (experimental group, n = 60) or no prophylaxis (control group, n = 59). All patients received regional anesthesia, preemptive analgesic medication, continuous femoral nerve block, periarticular injection, and fentanyl-based intravenous patient-controlled analgesia. We recorded the incidence of emetic events, rescue antiemetic requirements, complete response, pain level, and opioid consumption during three periods (0–6, 6–24, and 24–48 hours postoperatively). The severity of nausea was evaluated using a 0 to 10 VAS.
Results
The ramosetron group tended to have a lower incidence of nausea with a higher complete response and tended to have less severe nausea and fewer rescue antiemetic requirements during the 6- to 24-hour period. However, the overall incidences of emetic events, rescue antiemetic requirements, and complete response were similar in both groups. We found no differences in pain level or opioid consumption between the two groups.
Conclusions
Ramosetron reduced postoperative emetic events only during the 6- to 24-hour postoperative period and did not affect pain relief. More efficient measures to reduce emetic events after TKA should be explored.
Level of Evidence
Level I, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.
doi:10.1007/s11999-011-2208-0
PMCID: PMC3348324  PMID: 22161082
25.  Low glibenclamide concentrations affect endoplasmic reticulum stress in INS-1 cells under glucotoxic or glucolipotoxic conditions 
Background/Aims
β-Cell apoptosis caused by increased endoplasmic reticulum (ER) stress is an important pathogenic component of type 2 diabetes mellitus. In theory, sulfonylureas, used for the treatment of diabetes, can contribute to ER stress. We assessed changes in ER stress in pancreatic β-cells under glucotoxic or glucolipotoxic conditions using low concentrations of the sulfonylurea, glibenclamide (GB).
Methods
Low concentrations of GB (10 or 100 nM) were added to INS-1 cells cultured under glucotoxic or glucolipotoxic conditions. The degree of viability, level of apoptosis and levels of markers associated with ER stress were measured.
Results
Apoptosis decreased in response to low concentrations of GB under glucolipotoxic but not glucotoxic conditions. Most ER stress markers decreased upon the addition of GB. Under glucotoxic conditions, changes in the levels of ER stress markers were not consistent. However, all decreased significantly under glucolipotoxic conditions.
Conclusions
Low concentrations of GB exerted antiapoptotic effects through the attenuation of ER stress under glucolipotoxic conditions.
doi:10.3904/kjim.2013.28.3.339
PMCID: PMC3654132  PMID: 23682228
Glyburide; Insulin-secreting cells; Endoplasmic reticulum stress; Glucotoxicity; Glucolipotoxicity

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