Hepatitis B virus X Protein Promotes Liver Cancer Progression through Autophagy Induction in Response to TLR4 Stimulation

Hepatitis B virus X (HBx) protein has been reported as a key protein regulating the pathogenesis of HBV-induced hepatocellular carcinoma (HCC). Recent evidence has shown that HBx is implicated in the activation of autophagy in hepatic cells. Nevertheless, the precise molecular and cellular mechanism by which HBx induces autophagy is still controversial.Herein, we investigated the molecular and cellular mechanism by which HBx is involved in the TRAF6-BECN1-Bcl-2 signaling for the regulation of autophagy in response to TLR4 stimulation, therefore influencing the HCC progression. HBx interacts with BECN1 (Beclin 1) and inhibits the association of the BECN1-Bcl-2 complex, which is known to prevent the assembly of the pre-autophagosomal structure. Furthermore, HBx enhances the interaction between VPS34 and TRAF6-BECN1 complex, increases the ubiquitination of BECN1, and subsequently enhances autophagy induction in response to LPS stimulation. To verify the functional role of HBx in liver cancer progression, we utilized different HCC cell lines, HepG2, SK-Hep-1, and SNU-761. HBx-expressing HepG2 cells exhibited enhanced cell migration, invasion, and cell mobility in response to LPS stimulation compared to those of control HepG2 cells. These results were consistently observed in HBx-expressed SK-Hep-1 and HBx-expressed SNU-761 cells. Taken together, our findings suggest that HBx positively regulates the induction of autophagy through the inhibition of the BECN1-Bcl-2 complex and enhancement of the TRAF6-BECN1-VPS34 complex, leading to enhance liver cancer migration and invasion.

Clinical study on screw loosening in dental implant prostheses: a 6-year retrospective study

Objectives@#In this study, we determined the incidence and pattern of screw loosening in patients who received dental implants. @*Materials and Methods@#Patients who received implants between January 2008 and October 2013 and completed their prosthetic rehabilitation were evaluated for the incidence, frequency, and onset of screw loosening using dental charts and radiographs. The association between each factor and screw loosening was analyzed using the chi-square test and a multivariate analysis with binary logistic regression models (P<0.05). @*Results@#Total 1,928 implants were placed in 837 patients (448 males, 389 females), whose follow-up period after loading varied from 0.25 to 70 months (mean period, 31.5 months). Screw loosening occurred in 7.2% of implants. Most cases occurred less than six months after loading. Among those, 22.3% experienced recurrent screw loosening. Screw loosening was most common in the molar region (8.5%) and frequently associated with an implant diameter of ≥5 mm (14.2%). External implant–abutment connections (8.9%) and screw-retained implant prostheses (10.1%) showed higher incidence of problems than internal implant–abutment connections and cement-retained implants, respectively. Screw loosening was most common in implant prostheses with single crowns (14.0%). @*Conclusion@#Within the limits of the current study, we conclude that the incidence of screw loosening differs significantly according to the position of implant placement, the type of implant and manufacturer, implant diameter, the type of implant–abutment connection, the type of retention in the implant prosthesis, and the type of implant prosthesis.

Clinical Characteristics of Campylobacter Enterocolitis in Korean Adults: A Retrospective Study at a Single Center / 대한소화기학회지

Background/Aims@#Although the diarrheal disease caused by Campylobacter bacteria has been continuously increasing in Korea, there has been limited study on the clinical aspects of Campylobacter enteritis in adults in Korea. The purpose of this study was to analyze the clinical features and characteristics of adult patients with Campylobacter enteritis. @*Methods@#This retrospective study included patients diagnosed with Campylobacter enterocolitis at Nowon Eulji University Hopsital between January 2016 and December 2017. Campylobacter enterocolitis was diagnosed through polymerase chain reaction of stools from patients with acute diarrhea. @*Results@#Among 630 hospitalized patients with acute diarrhea, Campylobacter enterocolitis was diagnosed in 88 patients (14.0%). The mean age was 37.9±19.1 years. Campylobacter enterocolitis was most prevalent in the summer (52 patients, 59.1%). Patients exhibited more than 10 times of diarrhea in 36 (40.9%), high fever above 39℃ in 19 (21.59%), and abdominal pain above 5 points on the numeric rating scale in 23 (26.14%) cases. In abdominal CT scan, pancolitis was found in 58 patients (65.9%). Small intestine was involved in 37 patients (42.4%). Mean CRP was 10.14 mg/dL (range 0.72-32.27 mg/dL). The duration of diarrhea after antibiotics treatment was 2.34±1.51 days in the ciprofloxacin treatment group and 2.26±1.71 days in the 3rd cephalosporin treatment group. @*Conclusions@#Campylobacter enterocolitis was common during summer. Commonly healthy young adults were hospitalized due to severe symptoms of Campylobacter enterocolitis. Whole colon and small bowel were frequently involved. Most patients were treated with antibiotics, and the efficacy of 3rd cephalosporin treatment was not inferior to that of ciprofloxacin treatment.

p62 Negatively Regulates TLR4 Signaling via Functional Regulation of the TRAF6-ECSIT Complex

Sequestosome 1 (SQSTM1, p62), a ubiquitin binding protein, plays a role in cell signaling, oxidative stress, and autophagy. However, its functional role in inflammatory signaling is controversial. Recent studies have shown that p62 is negatively implicated in inflammatory responses. But, the precise molecular mechanisms by which p62 regulates inflammatory responses remain unclear. In this study, we report on a new regulatory role for p62 in TLR4-mediated signaling. p62 overexpression led to the suppression of NF-κB activation and the production of pro-inflammatory cytokines, TNF-α, IL-6, and IL-1β in response to TLR4 stimulation. In contrast, p62(−/−) mouse embryonic fibroblast (MEF) cells exhibited marked enhancement of NF-κB activation and production of pro-inflammatory cytokines by TLR4 stimulation, compared to p62(+/+) MEF cells. Additionally, the TLR4-induced activation of signal transduction was significantly augmented in p62(−/−) MEF cells, indicating that p62 was negatively implicated in TLR4-mediated signaling. Biochemical studies revealed that p62 interacted with the internal domain of evolutionarily conserved signaling intermediate in Toll pathways (ECSIT), which is critical for associating with the TNF receptor associated factor 6 (TRAF6)-ECSIT complex to activate NF-κB in TLR4 signaling. Interestingly, p62-ECSIT interaction inhibited the interaction between TRAF6 and ECSIT and attenuated the ubiquitination of ECSIT. Furthermore, upon LPS challenge, the mortality of p62(−/−) (p62-knockout) mice was markedly enhanced compared to p62(+/+) (p62 wild-type) mice. Taken together, our data demonstrate that p62 negatively regulated TLR4 signaling via functional regulation of the TRAF6-ECSIT complex.

Oncologic Outcomes in Patients Who Undergo Neoadjuvant Chemoradiotherapy and Total Mesorectal Excision for Locally Advanced Rectal Cancer: A 14-Year Experience in a Single Institution

PURPOSE: This study evaluated the oncologic outcomes of locally advanced rectal cancer patients who underwent preoperative neoadjuvant chemoradiotherapy (CRT) followed by surgery and determined the prognostic significance of pathologic complete response (pCR). METHODS: Between January 2002 and December 2015, 580 patients with rectal cancer who underwent surgery after neoadjuvant CRT were identified. Survival according to tumor response to CRT and pathologic stage was analyzed using the Kaplan-Meier method, and the Cox proportional hazard model was used to identify factors associated with survival outcomes. RESULTS: A total of 111 patients (23.7%) achieved pCR while the other 469 patients showed residual disease. Patients with pCR had a lower pretreatment carcinoembryonic antigen level and earlier cT classification than those with residual disease. With a median follow-up of 78 months, disease-free survival (DFS) and overall survival (OS) were significantly better in the pCR group than in the residual disease group. The 5-year DFS and 5-year OS for patients with ypStage 0, I, II, or III were 92.5%, 85.1%, 72.2%, 54.3% (P < 0.001) and 94.5%, 91.0%, 83.1%, 69.3%, respectively (P < 0.001). Pathologic AJCC stage after CRT was the most statistically significant independent predictor of OS (HR, 6.97 [95% confidence interval, 3.16–15.39] for stage III vs. stage 0) and DFS (HR, 7.30 [95% confidence interval, 3.63–14.67] for stage III vs. stage 0). CONCLUSION: Rectal cancer patients who achieved pCR showed improved survival compared to those with residual disease after preoperative CRT. Moreover, pCR was an independent indicator of OS and DFS, and pathologic AJCC stage was correlated with survival after preoperative CRT.

Analysis of variations in anesthesia cost according to severity of physical status and cancer stage in colorectal cancer patients

BACKGROUND: Since the late 2000s, the number of anesthesia performed has increased yearly. However, there has not been research into the appropriate cost of anesthesia based on the difficulty of anesthesia performed, the number of medical personnel participated, and materials administered for anesthesia. The purpose of this study was to analyze the variations in anesthesia cost according to severity of their physical status and cancer stage in patients who had undertaken colorectal cancer surgeries. METHODS: In order to analyze the cost of anesthesia for colorectal cancer surgery, we used Electronic Data Interchange data from 2011 to 2012 of the three superior general hospitals in Seoul. Colorectal cancer codes were limited to seven codes included in the cancer screening statistics of the Health Insurance Review and Assessment Service. Based on these data, a frequency analysis and a multiple linear regression analysis were performed. RESULTS: There was no variation in the cost of anesthesia according to gender and age. However, the ASA physical status (PS) class and the cancer stage variables were confirmed to modify the anesthesia cost. CONCLUSIONS: These study imply that there is a difference in the technology used for anesthesia by medical personnel as well as the anesthesia related materials used according to the ASA PS and the cancer stage among patients having the same disease.

Femoral Footprint for Anatomical Single-Bundle Anterior Cruciate Ligament Reconstruction: A Cadaveric Study

PURPOSE: To identify the femoral footprint of the anterior cruciate ligament (ACL) in Koreans. MATERIALS AND METHODS: Eighteen embalmed cadaveric knees (mean age, 70 years) were examined. First, the shape of the ACL was determined macroscopically. After the ACL femoral footprint was defined, the ACL was cut from the femur and a Kirschner wire was inserted into the center of the ACL, and the position was verified with a C-arm. The position was quantified on the C-arm field using the quadrant method. The length and width of the ACL were measured. RESULTS: Macroscopically, the ACL is a flat single bundle with an average length of 34 mm and an average width of 9 mm. On average, the center of the ACL insertion site measured with the quadrant method was positioned at 29.5%±2.8% in an anterior direction (from posterior), and at 38.5%±3.2% in a distal direction (from Blumensaat's line). The anterior and posterior margins of the ACL femoral footprint were the resident's ridge and the cartilage margin of the lateral femoral condyle, respectively. CONCLUSIONS: The center of the ACL femoral footprint is positioned more anteriorly and distally than the positions identified in previous studies.

Transanal Endoscopic and Transabdominal Robotic Total Mesorectal Excision for Mid-to-Low Rectal Cancer: Comparison of Short-term Postoperative and Oncologic Outcomes by Using a Case-Matched Analysis

PURPOSE: This study aimed to compare short-term postoperative and oncologic outcomes of a transanal endoscopic total mesorectal excision (TME) to those of a transabdominal robotic TME. METHODS: A total of 62 patients with rectal cancer underwent transanal (n = 26) or robotic (n = 36) TME between June 2013 and December 2014. After case-matching by tumor location and TNM stage, 45 patients were included for analysis. The median follow-up period was 21.3 months. Operative, histopathologic and postoperative outcomes and recurrences were analyzed. RESULTS: Patients younger than 60 years of age were more frequently observed in the robotic TME group (75.0% vs. 47.6%, P = 0.059), but tumor location, cT and cN category, and preoperative chemoradiotherapy were not different between the 2 groups. Estimated blood loss was greater in the transanal group (283 mL vs. 155 mL, P = 0.061); however, the operation time and the rate of a diverting ileostomy and subsequent ileostomy repair were not different between the groups. The proximal resection margin was longer in the transanal TME group (20.8 cm ± 16.0 cm, P = 0.030), but the distal resection margins, involvements of the circumferential resection margin, TME quality, numbers of retrieved lymph nodes, postoperative complications, including anastomotic leak and voiding difficulty, and recurrence rates for the 2 groups were not statistically different. CONCLUSION: Transanal endoscopic and transabdominal robotic TME showed similar histopathologic and postoperative outcomes with the exception of the estimated blood loss and the proximal resection margin for a select group of patients.

Normal aging: definition and physiologic changes

Aging is a process of the progressive functional decline with time, leading to disability, dependence, morbidity, and mortality. While the organ function in the elderly is relatively uncompromised under basal conditions, their ability to tolerate increased physiologic stress is reduced. And the extent and onset of the deterioration in functional reserve is quite diverse from patient to patient. The aging population is rapidly growing and their medical management is becoming one of the greatest challenges to anesthesiologists. The understanding of the normal physiologic changes with aging is essential to frame any discussion of perioperative management in the elderly. In this review, we will focus on the physiologic changes in neurologic, cardiac, pulmonary, renal, and hepatic function, and thermoregulation.

Endoscopic Treatment of Mirizzi Syndrome in a Patient with Low Lying Cystic Duct and Remnant Cystic Duct Stone / 대한췌담도학회지

Mirizzi syndrome is a rare complication, resulting in bile duct obstruction and jaundice that usually arise from impacted gallstone in the cystic duct or neck of the gallbladder. It is vitally important to confirm underlying cystic duct anomaly in Mirizzi syndrome since it can produce surgical difficulty and higher complications. Generally, Mirizzi syndrome is treated surgically while endoscopic treatment is limited. Herein, we present Mirizzi syndrome with low lying cystic duct and remnant cyst duct calculi treated successfully by biliary stent and administration of choleretic agent, following by balloon dilatation on cystic duct and balloon extraction of the stone.

Endoscopic Treatment of Mirizzi Syndrome in a Patient with Low Lying Cystic Duct and Remnant Cystic Duct Stone / 대한췌담도학회지

Mirizzi syndrome is a rare complication, resulting in bile duct obstruction and jaundice that usually arise from impacted gallstone in the cystic duct or neck of the gallbladder. It is vitally important to confirm underlying cystic duct anomaly in Mirizzi syndrome since it can produce surgical difficulty and higher complications. Generally, Mirizzi syndrome is treated surgically while endoscopic treatment is limited. Herein, we present Mirizzi syndrome with low lying cystic duct and remnant cyst duct calculi treated successfully by biliary stent and administration of choleretic agent, following by balloon dilatation on cystic duct and balloon extraction of the stone.

Comparison of Peritoneal Dialysis and Hemodialysis Patients Following Extended Treatment Periods in a Single Center / 대한내과학회지

BACKGROUND/AIMS: Improvements in dialysis therapies and patient care are leading to more patients receiving dialysis for longer periods of time. Survival rates with peritoneal dialysis (PD) are superior to those with hemodialysis (HD) during the initial 2-3 years; however, data comparing the outcomes of these two methods are lacking. Thus, we performed a retrospective study of patients treated with dialysis for longer than 3 years to investigate patient condition according to mode of dialysis. METHODS: A total of 80 patients currently being treated by dialysis for at least 36 months at the Eulji Medical Center were included in this study. Patients' laboratory data and admissions histories over the prior 3 years were reviewed. Dialysis adequacy, body composition, and cytokine levels were quantified. RESULTS: A total of 39 PD and 41 HD patients, with no difference in mean age or gender, were compared. Regarding dialysis adequacy, 97.5% of HD patients met the criterion of 1.2 Kt/V or higher, whereas only 58% of PD patients satisfied the required weekly Kt/V of 1.7. Inflammatory cytokines were significantly elevated in PD patients; however, PD patients with adequate dialysis expressed the same inflammatory cytokines as HD patients. CONCLUSIONS: The delivery of adequate dialysis to PD patients over extended periods of time is difficult. Thus, more rigorous management of PD patients is required to avoid insufficient dialysis and inflammation.

The Well-Being and Treatment Satisfaction of Diabetic Patients in an Outpatient Setting at a General Hospital in Korea / 임상당뇨병

BACKGROUND: The aim of this study was to assess the psychological well-being and treatment satisfaction in patients with type 2 diabetes mellitus in a general hospital in Korea. METHODS: This study included 440 type 2 diabetes patients above 20 years of age. Well-Being Questionnaire-12 (WBQ-12) and Diabetes Treatment Satisfaction Questionnaire were used to survey well-being and treatment satisfaction, respectively. WBQ-12 consists of 4 categories: negative well-being (NWB), energy (ENE), positive well-being (PWB), and general well-being (GWB). RESULTS: There were significant associations between NWB scores and women, low education, low-income, and number of hospital admissions. Significant associations were also identified between ENE scores and men, higher education, insulin nonusers, high-income, compliance with recommended exercise, number of medications, satisfaction with treatment time, and poor glycemic control. PWB scores were significantly associated with high-income, satisfaction with waiting and treatment times, compliance with recommended diet and exercise, and number of medications. GWB scores were significantly associated with men, higher education, high-income, satisfaction with waiting and treatment times, compliance with recommended exercise, and number of medications. Treatment satisfaction was significantly associated with age, satisfaction with waiting and treatment times, compliance with recommended diet and exercise, and duration of diabetes. CONCLUSION: Diabetes care requires psychosocial support in addition to medical care. Unlike Western studies, our study found that satisfaction with waiting and treatment times had a strong correlation with well-being and treatment satisfaction in diabetes patients.

The State of Anesthetic Services in Korea: A National Survey of the Status of Anesthesia Provider in the 2011-2013 Period

Active involvement of anesthesiologists in perioperative management is important to ensure the patients' safety. This study aimed to investigate the state of anesthetic services in Korea by identifying anesthetic service providers. From the insurance claims data of National Health Insurance for 3 yr, the Korean state of anesthetic services was analyzed. The claims for anesthesia from the medical institutions which hire their own anesthesiologist or with an anesthesiologist invitation fee are assumed to be the anesthesia performed by anesthesiologists. The annual anesthetic data were similar during the study period. In 2013, total counts of 2,129,871 were composed with general anesthesia (55%), regional anesthesia (36%) and procedural sedation with intravenous anesthetics (9%). About 80% of total cases of general anesthesia were performed in general hospitals, while more than 60% of the regional anesthesia and sedation were performed in the clinics and hospitals under 100 beds. Non-anesthesiologists performed 273,006 cases of anesthesia (13% of total) including 36,008 of general anesthesia, 143,134 of regional anesthesia, and 93,864 of sedation, mainly in the clinics and hospitals under 100 beds. All procedural sedations in the institutions without direct employed anesthesiologist were performed by non-anesthesiologists. Significant numbers of anesthesia are performed by non-anesthesiologist in Korea. To promote anesthetic services that prioritize the safety of patients, the standard to qualify anesthetic service is required. Surgeons and patients need to enhance their perception of anesthesia, and the payment system should be revised in a way that advocates anesthesiologist-performed anesthetic services.

Anterolateral Meniscofemoral Ligament of the Lateral Meniscus

Anatomical variations of the meniscus are a common anomaly that knee surgeons frequently encounter. However, anomalies of the anterior horn of the lateral meniscus (AHLM) are extremely rare. In this report, we present a newly discovered anomaly of the AHML: an anterolateral meniscofemoral ligament is described with clinical features and radiographic and arthroscopic findings.

Efficiency and Safety of Demineralized Bone Matrix for Posterolateral Fusion / 대한정형외과학회잡지

PURPOSE: The purpose of this study is to analyze the effects of demineralized bone matrix on posterolateral lumbar fusion. MATERIALS AND METHODS: From 2009 to 2012, 30 patients who had undergone posterolateral fusions using demineralized bone matrix (group I) and 30 who had received autogenous posterior iliac bone grafts (group II) were investigated. Bone union was determined by evaluating serial simple lumbar radiographs taken during the 24 months after surgery. Bone status was classified according to Lenke's scale and the bone fusion was finally determined by flexion/extension lateral radiographs. We also examined halo signs around the pedicular screws evident on the radiographs, scored back pain using a visual analogue scale (VAS), and Oswestry disability index (ODI) score 2 years after surgery to evaluate clinical status of patients. RESULTS: In group I, 19 patients showed union and 11 patients did not; the values for group II were 22 and 8. These proportions did not differ significantly (p=0.57). Time to union was somewhat shorter in group II (25.3±7.9 weeks), but did not differ significantly from that of group I (p=0.097). No statistical significance in the periscrew Halo count, VAS for back pain, and ODI score was observed between the two groups. CONCLUSION: The union rate after using demineralized bone matrix for lumbar posterolateral fusion is similar to that attained when autogenous bone grafts are employed, and lacks the morbidity associated with such grafts. Thus, demineralized bone matrix is an effective bone graft substitute when posterolateral fusion surgery of the lumbar spine is required.

Peroxiredoxin-3 Is Involved in Bactericidal Activity through the Regulation of Mitochondrial Reactive Oxygen Species

Peroxiredoxin-3 (Prdx3) is a mitochondrial protein of the thioredoxin family of antioxidant peroxidases and is the principal peroxidase responsible for metabolizing mitochondrial hydrogen peroxide. Recent reports have shown that mitochondrial reactive oxygen species (mROS) contribute to macrophage-mediated bactericidal activity in response to Toll-like receptors. Herein, we investigated the functional effect of Prdx3 in bactericidal activity. The mitochondrial localization of Prdx3 in HEK293T cells was confirmed by cell fractionation and confocal microscopy analyses. To investigate the functional role of Prdx3 in bactericidal activity, Prdx3-knockdown (Prdx3(KD)) THP-1 cells were generated. The mROS levels in Prdx3(KD) THP-1 cells were significantly higher than those in control THP-1 cells. Moreover, the mROS levels were markedly increased in response to lipopolysaccharide. Notably, the Salmonella enterica serovar Typhimurium infection assay revealed that the Prdx3(KD) THP-1 cells were significantly resistant to S. Typhimurium infection, as compared with control THP-1 cells. Taken together, these results indicate that Prdx3 is functionally important in bactericidal activity through the regulation of mROS.

Charged MVB protein 5 is involved in T-cell receptor signaling

Charged multivesicular body protein 5 (CHMP5) has a key role in multivesicular body biogenesis and a critical role in the downregulation of signaling pathways through receptor degradation. However, the role of CHMP5 in T-cell receptor (TCR)-mediated signaling has not been previously investigated. In this study, we utilized a short hairpin RNA-based RNA interference approach to investigate the functional role of CHMP5. Upon TCR stimulation, CHMP5-knockdown (CHMP5(KD)) Jurkat T cells exhibited activation of TCR downstream signaling molecules, such as PKCθ and IKKαβ, and resulted in the activation of nuclear factor-κB and the marked upregulation of TCR-induced gene expression. Moreover, we found that activator protein-1 and nuclear factor of activated T-cells transcriptional factors were markedly activated in CHMP5(KD) Jurkat cells in response to TCR stimulation, which led to a significant increase in interleukin-2 secretion. Biochemical studies revealed that CHMP5 endogenously forms high-molecular-weight complexes, including TCR molecules, and specifically interacts with TCRβ. Interestingly, flow cytometry analysis also revealed that CHMP5(KD) Jurkat T cells exhibit upregulation of TCR expression on the cell surface compared with control Jurkat T cells. Taken together, these findings demonstrated that CHMP5 might be involved in the homeostatic regulation of TCR on the cell surface, presumably through TCR recycling or degradation. Thus CHMP5 is implicated in TCR-mediated signaling.

Quercetin Directly Interacts with Vitamin D Receptor (VDR): Structural Implication of VDR Activation by Quercetin

The vitamin D receptor (VDR) is a member of the nuclear receptor (NR) superfamily. The VDR binds to active vitamin D3 metabolites, which stimulates downstream transduction signaling involved in various physiological activities such as calcium homeostasis, bone mineralization, and cell differentiation. Quercetin is a widely distributed flavonoid in nature that is known to enhance transactivation of VDR target genes. However, the detailed molecular mechanism underlying VDR activation by quercetin is not well understood. We first demonstrated the interaction between quercetin and the VDR at the molecular level by using fluorescence quenching and saturation transfer difference (STD) NMR experiments. The dissociation constant (K(d)) of quercetin and the VDR was 21.15 ± 4.31 µM, and the mapping of quercetin subsites for VDR binding was performed using STD-NMR. The binding mode of quercetin was investigated by a docking study combined with molecular dynamics (MD) simulation. Quercetin might serve as a scaffold for the development of VDR modulators with selective biological activities.

Ligamentum Teres Injuries of the Hip / 대한정형외과학회잡지

PURPOSE: The purpose of this study is to identify functions of ligamentum teres during multi-planar movement of the hip joint and to evaluate the correlation between arthroscopic findings and preoperative magnetic resonance imaging (MRI) of ligamentum teres rupture. MATERIALS AND METHODS: With four fresh-frozen cadavers that were dissected for removal of all soft tissue from around the hip, leaving only the ligamentum teres intact, tension of ligamentum teres at each position of the hip during multiplanar movement of the hip joint was identified. Among patients who underwent arthroscopic treatment for hip joint lesion from June 2006 to December 2012, arthroscopic findings of 26 patients who showed ligamentum teres rupture on arthroscopy were compared retrospectively with finding of preoperative MRI and visual analogue scale pain score and modified Harris hip score preoperatively and at final follow-up were evaluated. RESULTS: The ligamentum teres was maximal taut at flexion with external rotation. Ligamentum teres rupture was suspected according to preoperative MRI in 20 cases (76.9%). All cases underwent arthroscopic debridement and thermal shrinkage for the ruptured ligamentum teres. At final follow-up, visual analogue scale pain score and modified Harris hip score had improved from 6.1 (4-9) and 63.7 (36.3-86.9) to 2.0 (0-5) and 88.4 (72.6-100), respectively (all p<0.001). CONCLUSION: The ligamentum teres is maximal taut at flexion with external rotation and contributes to internal stability. Ruptured ligamentum teres should be treated by arthroscopic debridement and thermal shrinkage.