Chong Bum Chang

• MD, PhD
• Professor at Seoul National University

High tibial osteotomy (HTO) for varus knee osteoarthritis traditionally aims to overcorrect the mechanical tibiofemoral angle (mTFA) to become valgus. However, valgus overcorrection in HTO increases problems such as knee joint line abnormality, hinge fracture, and patellar height change. Thus, there is a trend to avoid overcorrection, but biomechan...

UDP-GlcNAc serves as a building block for glycosaminoglycan (GAG) chains in cartilage proteoglycans and simultaneously acts as a substrate for O-GlcNAcylation. Here, we show that transporters for UDP-GlcNAc to the endoplasmic reticulum (ER) and Golgi are significantly downregulated in osteoarthritic cartilage, leading to increased cytosolic UDP-Glc...

Osteonecrosis (ON) of the knee is broadly categorized into two main types: spontaneous and secondary ON [1, 2]. Spontaneous ON of the knee, also known as SPONK, was first recognized as a distinct condition by Ahlback et al. in 1968, characterized by the absence of an identifiable cause [1, 3]. However, in recent times, SPONK is often regarded as a...

Purpose The purpose of this study was to evaluate whether IV dexamethasone, within the current multimodal pain management protocol, (1) could maintain postoperative pain at a comparable level without IV PCA, (2) could reduce opioids-related side effects, and (3) whether an additional dose of dexamethasone on POD 2 would offer further pain-relieving...

Background Periprosthetic fracture (PPF) is a troublesome complication as it utilizes substantial healthcare resources. Recent studies about the epidemiology of PPF after total knee arthroplasty (TKA) are still lacking, and there is limited national-level analysis focusing on the comorbid chronic conditions as risk factors of PPF. This study used n...

BACKGROUND Patellofemoral pain (PFP) is a common musculoskeletal disorder characterized by persistent knee pain, often without any structural abnormalities. Conservative treatments, particularly exercise therapy, are widely recommended; however, adherence remains generally low and full recovery is often not achieved. Psychological interventions can...

Background: Patellofemoral pain is a prevalent knee condition affecting up to 40% of individuals, especially females aged teens to 50s. Standard treatments, including exercise therapy, often yield insufficient long-term results, partly due to low compliance and psychological factors like depression and catastrophizing of pain. A digital therapeutic...

Purpose Presoaking the graft with vancomycin before implantation has been shown to reduce the risk of postoperative infection after anterior cruciate ligament reconstruction (ACLR). However, the effects of presoaking on the graft biomechanical properties remain unclear. This study aimed to determine whether presoaking the graft with vancomycin affe...

High tibial osteotomy (HTO) for varus knee osteoarthritis traditionally aims to overcorrect the mechanical tibiofemoral angle (mTFA) to become valgus. However, valgus overcorrection in HTO increases problems such as knee joint line abnormality, hinge fracture, and patellar height change. Thus, there is a trend to avoid overcorrection, but biomechan...

Background Achieving appropriate alignment after total knee arthroplasty (TKA) is crucial for long-term survival of implant but alignment in sagittal plane is relatively not well studied. The purpose of this study was to (1) propose the preoperative sagittal planning method of TKA using X-ray, (2) validate its accuracy and (3) find factors contribu...

Background This study aimed to analyze the life expectancy and cause of death in osteoarthritis (OA) patients who underwent total knee arthroplasty (TKA) and to identify risk factors that affect long-term mortality rate after TKA. Methods Among 601 patients, who underwent primary TKA due to OA by a single surgeon from July 2005 to December 2011, w...

Objective Interferon regulatory factor 1 (IRF1) is a transcriptional regulator conventionally associated with immunomodulation. Recent molecular analyses mapping DNA binding sites of IRF1 have suggested its potential function in DNA repair. However, the physiologic significance of this noncanonical function remains unexplored. Here, we investigated...

Background The Kellgren-Lawrence (KL) grading system is the most widely used method to classify the severity of osteoarthritis (OA) of the knee. However, due to ambiguity of terminology, the KL system showed inferior inter- and intra-observer reliability. For a more reliable evaluation, we recently developed novel deep learning (DL) software known...

This study aimed to determine whether the repair of a medial meniscus posterior root tear (MMPRT) is effective for MMPRT healing, cartilage regeneration, and clinical outcomes in opening wedge high tibial osteotomy (OWHTO). This retrospective study included 80 patients who underwent OWHTO and subsequent second-look arthroscopy. The patients were di...

The effectiveness of Floseal, a thrombin-based hemostatic matrix, in total knee arthroplasty (TKA) in minimizing blood loss and transfusion requirements remains a topic of debate. This meta-analysis aims to evaluate the up-to-date randomized controlled trials (RCTs) on the efficacy and safety of Floseal in TKA. A comprehensive search was conducted...

Introduction: This study aimed to determine whether there was a relationship between preoperative patient-reported outcome measures (PROMs) and satisfaction after total knee arthroplasty (TKA), and whether there was a relationship between the amount of improvement in PROM or final PROM and satisfaction and whether that relationship differed 1 and...

Although the use of intra-articular polynucleotide (IA PN) injection as a viscosupplement for knee osteoarthritis (OA) treatment has been proposed, its efficacy and safety compared to high molecular weight hyaluronic acid (HMWHA) injection has not yet been established. The present double-blind, multicenter, randomized controlled trial aimed to inve...

Background: This study aimed to 1) assess the effect of total hip arthroplasty (THA) on coronal limb alignment, namely, the hip-knee-ankle angle (HKA), 2) identify factors that determine changes in the HKA, and 3) determine whether alignment changes influence the knee joint space width. Methods: We retrospectively evaluated 266 limbs of patients...

Introduction Digital healthcare systems based on augmented reality (AR) show promise for postoperative rehabilitation. We compared the effectiveness of AR-based rehabilitation and conventional rehabilitation after total knee arthroplasty (TKA). Materials and methods We randomly allocated 56 participants to digital healthcare rehabilitation group (...

Background: Healthcare services have been restricted after the coronavirus disease 2019 (COVID-19) outbreak. With the pandemic still ongoing, the patterns of orthopedic surgery might have changed. The purpose of this study was to determine whether the reduced volumes of orthopedic surgery were recovered over time. Among the trauma and elective sur...

Background With increasing interest in enhanced recovery after surgery (ERAS), the literature on ERAS in orthopedic surgery is also rapidly accumulating. This review article aims to (1) summarize the components of the ERAS protocol applied to orthopedic surgery, (2) evaluate the outcomes of ERAS in orthopedic surgery, and (3) suggest practical stra...

PurposeThis prospective randomized controlled trial aimed to determine whether the limited use of tourniquets during total knee arthroplasty (TKA) would be more beneficial under the contemporary enhanced recovery after surgery (ERAS) protocol than the conventional use of tourniquets.Methods One hundred patients with knee osteoarthritis who underwen...

Background: A considerable proportion of patients warranting total knee arthroplasty (TKA) have night pain, neuropathic pain, and/or depressive disorder, which may not be resolved by TKA. This prospective, longitudinal cohort study aimed to document the prevalence of night pain, neuropathic pain, and depressive disorder in patients with advanced k...

Background: The viability of augmenting small-diameter hamstring autografts with allografts remains unclear. Recent studies have reported different clinical results after allograft augmentation. Hence, we sought to determine whether hamstring autografts and hybrid grafts differed in terms of failure rates and functional outcomes after anterior cruc...

Purpose This study aimed to elucidate the effect of medial meniscus posterior root (MMPR) repair during opening-wedge high tibial osteotomy (OWHTO) in terms of contact pressure (CP) and contact area (CA). Methods Nine fresh-frozen human cadaveric knee specimens were included. Each specimen was tested under nine conditions comprising 3 different de...

Background We sought to determine (1) the success rate of debridement, antibiotics, and implant retention (DAIR) for acute periprosthetic joint infection (PJI) of the knee in patients with acute postsurgical infection and in those with acute hematogenous infection via a multicenter study, (2) the factors related to the failure of DAIR for overall a...

The choice of implant used for primary total knee arthroplasty (TKA) may have an impact on clinical outcomes. Clinical outcomes after TKA with gradually reducing radius implants (group G) vs single-radius implants (group S) were evaluated among Asian patients. This study included 541 patients (754 knees) in group G and 187 patients (275 knees) in g...

Background: The purpose of this study was to analyze the epidemiology of T-score discordance between the spine and femur in the South Korean population and compare the prevalence of T-score discordance between the Korean osteoporosis population and atypical femoral fracture (AFF) patients. Methods: A total of 12,422 subjects from the Korea Natio...

Background Highly cross-linked polyethylene (HXLPE) liners have been developed to address the wear-related problems associated with conventional polyethylene (CPE) such as osteolysis or aseptic loosening in total hip arthroplasty (THA). In this systematic meta-analysis, we compared the long-term efficacy in preventing radiological osteolysis and re...

This study aimed to (1) evaluate the preoperative Hb cut-off value for transfusion after unilateral and bilateral staged (1 week apart) TKAs, respectively, and (2) determine whether cause of preoperative anemia can affect transfusion rate after TKA. A total of 951 patients who underwent TKA (unilateral: 605, bilateral staged: 346) from 2016 to 2019...

Aging and mechanical overload are prominent risk factors for osteoarthritis (OA), which lead to an imbalance in redox homeostasis. The resulting state of oxidative stress drives the pathological transition of chondrocytes during OA development. However, the specific molecular pathways involved in disrupting chondrocyte redox homeostasis remain uncl...

Purpose: Total knee arthroplasty (TKA) is often performed sequentially on both sides during a single hospital stay. Patients who experience postoperative nausea and vomiting (PONV) after the first operation are concerned about PONV recurrence after the second operation. However, there are few studies regarding the incidence of PONV in staged bilat...

Objectives This study aimed to investigate the association of self-reported weight change and physical activity with the level of knee pain and health-related quality of life in East Asian women with knee osteoarthritis using population-based data. Methods A total of 564 women (mean age, 68.2 years, standard deviation, 8.9 years) aged 50 years or o...

Purpose This double-blind, randomized, Phase III clinical trial was conducted to assess the efficacy and safety of the novel divinyl sulfone cross-linked hyaluronate (YYD302) compared with the 1,4-butanediol diglycidyl ether cross-linked hyaluronate (Synovian) in patients with knee osteoarthritis. Methods A total of 184 patients with osteoarthriti...

Background: Tranexamic acid (TXA) is typically discontinued on the day of total knee arthroplasty (TKA). However, bleeding may persist for several days. We sought to determine whether sequential administration of intravenous (IV) and oral TXA could reduce hemoglobin (Hb) drop more than IV TXA alone. We also wanted to determine whether the use of a...

Background: Although a few studies have reported the incidence of deep vein thrombosis (DVT) after opening-wedge high tibial osteotomy (OWHTO), previous studies focused only on symptomatic DVT. Information is lacking regarding the overall incidence of DVT after OWHTO, thrombus location, and the relationship between DVT and clinical outcome. Purpo...

Background The anterolateral ligament of the knee (ALL) is a component of the lateral complex that stabilizes the structure against rotational force and may be associated with the outcome of anterior cruciate ligament (ACL) reconstruction (ACLR). Purpose To (1) find whether the visibility of the structure of the ALL is different in primary and rev...

Background Radiographic factors estimate the state of the static knee joint, and it is questionable how well these parameters reflect the dynamic knee condition. The external knee adduction moment (KAM) during gait is known to be a kinetic variable contributing to osteoarthritis progression. This study aims to investigate the effects of static radi...

Background We sought to determine whether administrations of intravenous (IV) dexamethasone jeopardize blood glycemic control, increase rates of postoperative complications and diabetic medication change after TKA. Methods This retrospective study included 427 patients with DM who underwent TKA. Patients were divided into two groups according to t...

Purpose: Although knee joint line orientation (KJLO) after total knee arthroplasty (TKA) has been emphasized as an important factor that can affect postoperative knee kinematics, the effect of foot position on KJLO has not been fully understood. This study aimed to (1) identify the anatomical and positional factors that determine KJLO after TKA, a...

Background Studies have reported that opening wedge high tibial osteotomy (OWHTO) without bone grafting has outcomes that are similar to or even better than those of OWHTO with bone grafting, especially after use of a locking plate. However, a consensus on managing the gap after OWHTO has not been established. Purpose To determine the degree of ga...

Cellular senescence is a complex stress response implicated in aging. Autophagy can suppress senescence but is counterintuitively necessary for full senescence. Although its anti-senescence role is well described, to what extent autophagy contributes to senescence establishment and the underlying mechanisms is poorly understood. Here, we show that...

The degree of cartilage degeneration assessed intraoperatively may not be sufficient as a criterion for patellar resurfacing in total knee arthroplasty (TKA). However, single-photon emission tomography/computed tomography (SPECT/CT) is useful for detecting osteoarthritic involvement deeper in the subchondral bone. The purpose of the study was to de...

In the published article, “Ho Sung Han, Chong Bum Chang, Duk-Chul Lee and Jee-Yon Lee, Relationship between total fruit and vegetable intake and self-reported knee pain in older adults. The journal of nutrition, health & aging. 21, 750–758 (2017), the affiliations were published incorrectly. The authors apologize for any inconvenience that it may h...

Introduction Implant material is a more important factor for periprosthetic tibial bone resorption than implant design after total knee arthroplasty (TKA). The virtual perturbation study was planned to perform using single case of proximal tibia model. We determined whether the implant materials’ stiffness affects the degree of periprosthetic tibia...

There is no established protocol regarding the timing of administration of antiemetics in patients undergoing total knee arthroplasty (TKA). The purpose of this study was to determine whether preoperative, rather than postoperative administration of an antiemetic could reduce postoperative nausea and vomiting (PONV) in patients undergoing TKA, and...

Although the importance of quadriceps femoris function was reported previously, little is known about volume-related factors and their effects on clinical outcomes after total knee arthroplasty (TKA). We sought to determine whether there was a bilateral difference in vastus medialis muscle volume measured on single-photon emission computed tomograp...

Background: We sought to determine whether there was a difference in the posterior condylar offset (PCO), posterior condylar offset ratio (PCOR) and clinical outcomes following total knee arthroplasty (TKA) with anterior referencing (AR) or posterior referencing (PR) systems. We also assessed whether the PCO and PCOR changes, as well as patient fa...

Chondrosarcomas, malignant cartilaginous neoplasms, are capable of transitioning to highly aggressive, metastatic, and treatment-refractory states, resulting in significant patient mortality. Here, we aim to uncover the transcriptional program directing such tumor progression in chondrosarcomas. We conduct weighted correlation network analysis to e...

PurposeAcute kidney injury (AKI) is a deleterious complication after total knee arthroplasty (TKA). The purposes of this study were to identify preoperative risk factors and develop a web-based prediction model for postoperative AKI, and assess how AKI affected the progression to ESRD.Method The study included 5757 patients treated in three tertiar...

Background This study aimed to (1) document the TKA use in Korea from 2010 to 2018, (2) evaluate whether rapid increase in TKA use has been maintained, and (3) estimate the projected TKA burden to 2030 based on the current use. Methods Using the Health Insurance Review and Assessment (HIRA) Korean database, procedural rate, growth rate, revision b...

Background This study aimed to investigate the change in ankle varus incongruencies following TKR in patients with preoperative genu varum deformity of ≥10°. Methods The study cohort was composed of patients who underwent TKR in a single institution for knee osteoarthritis with preoperative genu varum deformity of ≥10° and concomitant varus ankle...

Background We determined whether postoperative intravenous (IV) iron supplementation could reduce transfusion rate in patients undergoing staged bilateral total knee arthroplasty (TKA). Further, we examined whether hemoglobin (Hb) levels and iron profile differed between patients with and without postoperative IV iron supplementation. Methods This...

The aim of this study was to determine whether the infection control rate of a modified debridement, antibiotics, and implant retention (DAIR) protocol (DAIR with antibiotic-impregnated cement beads) is comparable to that of 2-stage revision for acute periprosthetic joint infection (PJI) after total knee arthroplasty (TKA). We also aimed to determi...

We aimed to investigate whether perioperative magnesium sulfate administration was associated with the incidence of chronic persistent postoperative pain (PPP) following total knee arthroplasty (TKA). This retrospective observational study was performed at a single tertiary academic hospital. We reviewed the medical records of adult patients who we...

Background To date, there has been no established protocol regarding the timing of the scheduled administration of antiemetics in total knee arthroplasty (TKA). Previous prospective studies analyzing the scheduled use of antiemetics differed in the timing at which the drugs were administered. However, antiemetic drugs are not administered post-oper...

Purpose: The purpose of this study was to evaluate the clinical efficacy and safety of treating patients with a cartilage defect of the knee with microfractures and porcine-derived collagen-augmented chondrogenesis technique (C-ACT). Methods: One hundred participants were randomly assigned to the control group (n = 48, microfracture) or the inve...

Background: Preoperative pain in the symptomatic knee may predict postoperative pain severity in patients undergoing total knee arthroplasty (TKA). However, the effect of preoperative pain external to the knee on postoperative pain is unclear. This study evaluated postoperative pain outcomes in TKA patients according to the presence of preoperativ...

Osteoarthritis (OA) is a prevalent degenerative disease, which involves progressive and irreversible destruction of cartilage matrix. Despite efforts to reconstruct cartilage matrix in osteoarthritic joints, it has been a difficult task as adult cartilage exhibits marginal repair capacity. Here we report the identification of tankyrase as a regulat...

Background: Maintenance of optimal knee joint line orientation (KJLO) is important after high tibial osteotomy (HTO). No tools, however, are currently available that could predict the value of postoperative KJLO before surgery. First, this study sought to determine the effects of various preoperative anatomical alignment parameters to postoperativ...

There is little information about the management and clinical outcomes of the periprosthetic fracture after total knee arthroplasty (TKA) with a stem extension. The purposes of this study were to demonstrate management of the periprosthetic fractures after TKA with a stem extension, to report treatment outcomes, and to determine whether dual-plate...

A progressive loss of cartilage matrix leads to the development of osteoarthritis (OA). Matrix homeostasis is disturbed in OA cartilage as the result of reduced production of cartilage-specific matrix and increased secretion of catabolic mediators by chondrocytes. Chondrocyte senescence is a crucial cellular event contributing to such imbalance in...

Introduction The role of unicompartmental knee arthroplasty (UKA) in spontaneous osteonecrosis of the knee (SONK) remains controversial, even though SONK involves only one compartment of the knee joint. We aimed to compare the survival rate and clinical outcomes of UKA in SONK and medial compartment osteoarthritis (MOA) via a meta-analysis of previ...

Background and objectives Data is insufficient to determine whether perioperative statin use increases or decreases postoperative pain. This study aimed to investigate the association between perioperative statin use and pain outcomes after total knee arthroplasty performed under spinal anesthesia. Methods This is a retrospective, observational st...

Background: A two-stage approach to total knee arthroplasty (TKA) using an antibiotic-impregnated articulating cement spacer is an option for an infected arthritic knee. Vancomycin combined with broad-spectrum antibiotics can be used to make an antibiotic-impregnated articulating cement spacer. Causative organisms are sometimes not confirmed befor...

Background This study aimed to determine the prevalence of excessive lateral pressure syndrome (ELPS) in potential candidates for high tibial osteotomy (HTO) using single-photon emission computed tomography–computed tomography (SPECT–CT). We also sought to identify risk factors related to the presence of ELPS. Methods This retrospective study incl...

The purpose of this study was to assess the overall clinical results and range of motion (ROM) after total knee arthroplasty (TKA) in patients with preoperative stiffness. We also aimed to determine whether the severity or cause of the stiffness can affect the clinical outcome after surgery. This retrospective study included 122 knees (117 patients...

Row data set used in the study. The entire dataset used in this study is presented in the file S1 Appendix. (XLSX)

Background Some patients with recurrent symptomatic instability after primary anterior cruciate ligament (ACL) reconstruction have an extension deficiency (ED). This study 1) compared preoperative clinical conditions between the ED and non‐ED groups undergoing revision ACL reconstruction, 2) documented clinical and arthroscopic findings in ACL‐reco...

Background: We sought to document the incidences of deep vein thrombosis (DVT) before and after total knee arthroplasty (TKA). In addition, we aimed to explor whether routine preoperative DVT evaluation was useful to establish DVT treatment strategies after TKA. Finally, we wanted to evaluate whether the incidences of DVT differed between patients...

Introduction: The aims of this study were to (1) assess the bone mineral density (BMD) around the knee joint, (2) determine the correlation between central and knee BMDs, and (3) investigate the factors associated with BMD around the knee joint in patients with knee osteoarthritis (OA). Methodology: This cross-sectional study included 122 patien...

Background: We aimed at determining whether the coronal alignment of lower extremity was related to rotational geometry of distal femur, femoral anteversion, and tibial torsion in patients with knee osteoarthritis. Methods: A total of 422 lower extremities were divided into 3 groups according to the coronal alignment: valgus (n = 31), neutral (n...

Background: Occasionally, patients experience new or increased ankle pain following total knee arthroplasty (TKA). The aims of this study were to determine (1) how the correction of varus malalignment of the lower limb following TKA affected changes in alignment of the ankle and hindfoot, (2) the difference in changes in alignment of the ankle and...

Background Recently, concerns arose over the medial tibial bone resorption of a novel cobalt-chromium (CoCr) implant. This study aimed to investigate the effects of tibial component material, design, and patient factors on periprosthetic bone resorption and to determine its association with clinical outcomes after total knee arthroplasty (TKA). Me...

Objective This study was performed to investigate the factors associated with the level of knee pain in a nationally representative sample of noninstitutionalized women aged 50 years or older. Methods Women aged 50 years or older were selected and included in the data analyses from the Korean National Health and Nutrition Examination Surveys (2010...

Background This cadaveric study aimed to demonstrate variation of the anterior cruciate ligament (ACL) tibial attachment in the sagittal plane, and to analyze the radiographic landmarks which predict the sagittal location of the ACL tibial attachment. Methods In 20 cadaveric knees, native ACLs were removed and the centers of the ACL tibial and fem...

BACKGROUND Relatively little is known about the longitudinal changes in strength and function in the early phase compared to long term outcome following reconstruction of the anterior cruciate ligament (ACL). OBJECTIVE To assess the isokinetic concentric strength of the knee extensors and flexors as well as the distance jumped in the one-legged ho...

Purpose Recurrent patellar dislocation is often associated with genu valgum. The purpose of this study was to analyze the short-term results of single-incision, closing-wedge distal femoral osteotomy (CWDFO) combined with medial reefing and lateral release for recurrent patellar instability with genu valgum. Materials and Methods Combined CWDFO/me...

AIM To assess the prevalence of possible risk factors of upper gastrointestinal bleeding (UGIB) and their age-group specific trend among the general population and osteoarthritis patients. METHODS We utilized data from the National Health Insurance Service that included claims data and results of the national health check-up program. Comorbid cond...

Objectives Knee pain is one of the most common symptoms of knee osteoarthritis (OA) that affects the quality of life in the older adults, and identifying the contributing factors of knee pain is important. We hypothesized that higher fruit and vegetable consumption might be associated with the severity of knee pain lower prevalence of severe knee p...