Validation of the Korean version of the Sleep Hygiene Practice Scale in a Non-Clinical Population.

OBJECTIVES: This study aimed to validate the Korean version of the sleep hygiene practice scale (SHPS-K) and determine its effectiveness in screening poor sleepers with insomnia. METHODS: Online survey was conducted using translated SHPS in Korean, the Korean versions of the Pittsburgh Sleep Quality Index (PSQI-K), Insomnia Severity Index (ISI-K), and Epworth Sleepiness Scale (KESS) in a non-clinical population. The internal consistency and test-retest reliability of the SHPS-K were assessed using Cronbach's alpha and intraclass correlation coefficients (ICC), respectively. Construct validity was evaluated using correlation analyses with other questionnaires and confirmatory factor analysis. We determined the cutoff values that could identify poor sleepers with insomnia symptoms (PSQI-K > 5 and ISI-K ≥ 15) using receiver operating characteristic analysis. RESULTS: A total of 484 participants (242 women, mean age of 43.8 years) were enrolled. The average SHPS-K score was 71.2, with no significant sex differences. Women had poorer sleep scheduling and timing behaviors, and men had poorer eating and drinking behaviors. Good internal consistency (Cronbach's alpha = 0.88) and test-retest reliability (ICC = 0.80) were observed. The SHPS-K was positively correlated with the PSQI-K (r = 0.55), ISI-K (r = 0.54), and KESS (r = 0.42). A cutoff value of 73 identified poor sleepers with insomnia (area under the curve = 0.828). CONCLUSIONS: The SHPS-K is a reliable instrument for evaluating sleep hygiene in non-clinical Korean populations.

Hospital admission risks and excess costs for neurological symptoms attributable to long-term exposure to fine particulate matter in New York State, USA.

BACKGROUND: Although emerging evidence suggests that PM2.5 is linked to neurological symptoms (NSs) via neuroinflammation, relevant studies are scarce. This study aimed to investigate the risks and excess costs of hospital admission for five NSs-fatigue, headache, dizziness, convulsion, and paralysis-attributable to long-term exposure to PM2.5 in New York State, USA. METHODS: We analyzed the New York Statewide Planning and Research Cooperative System (SPARCS) from 2010 to 2016. A Bayesian hierarchical model with integrated nested Laplace approximations was performed to estimate the risks and excess costs of hospital admission for NSs due to long-term exposure to PM2.5 at the county level. RESULTS: A 1 µg/m3 increase in lag 0-1 years PM2.5 was associated with an increased risk of headache and convulsion by 1.06 (1.01, 1.11) and 1.04 (1.01, 1.06), respectively. The excess hospital admission cost for five NSs attributable to lag 0-1 years PM2.5 above the new World Health Organization guideline (annual standard: 5 µg/m3) was $200.24 (95% CI: 6.00, 376.96) million during 2011-2016, recording the highest for convulsion ($153.73 [95% CI: 63.61, 244.19] million). CONCLUSIONS: This study provides quantitative estimates of risks and excess costs for NSs attributable to long-term PM2.5 and suggests that policies that reduce long-term PM2.5 concentration in accordance with the new WHO air quality guidelines can yield substantial health and economic benefits related to NSs in the New York State population.

Anti-N-Methyl-D-Aspartate Receptor (NMDAR) Encephalitis Associated With Mediastinal and Ovarian Teratomas: A Case Report.

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is the most common type of autoimmune encephalitis. Approximately 80% of patients with anti-NMDAR encephalitis are women. Tumors are detected in approximately 50% of female patients with anti-NMDAR encephalitis, of which 96% are ovarian teratomas. We describe the case of a 28-year-old woman diagnosed with anti-NMDAR encephalitis with mediastinal and bilateral ovarian teratomas in July 2019. The patient recovered following surgical management of the mediastinal mass and both ovarian teratomas, and immunotherapy. This case shows that teratomas can be found at multiple sites other than ovaries. Therefore, detecting teratomas using whole-body evaluation may be helpful for diagnosis and treatment.

De novo assembly and phasing of a Korean human genome.

Advances in genome assembly and phasing provide an opportunity to investigate the diploid architecture of the human genome and reveal the full range of structural variation across population groups. Here we report the de novo assembly and haplotype phasing of the Korean individual AK1 (ref. 1) using single-molecule real-time sequencing, next-generation mapping, microfluidics-based linked reads, and bacterial artificial chromosome (BAC) sequencing approaches. Single-molecule sequencing coupled with next-generation mapping generated a highly contiguous assembly, with a contig N50 size of 17.9 Mb and a scaffold N50 size of 44.8 Mb, resolving 8 chromosomal arms into single scaffolds. The de novo assembly, along with local assemblies and spanning long reads, closes 105 and extends into 72 out of 190 euchromatic gaps in the reference genome, adding 1.03 Mb of previously intractable sequence. High concordance between the assembly and paired-end sequences from 62,758 BAC clones provides strong support for the robustness of the assembly. We identify 18,210 structural variants by direct comparison of the assembly with the human reference, identifying thousands of breakpoints that, to our knowledge, have not been reported before. Many of the insertions are reflected in the transcriptome and are shared across the Asian population. We performed haplotype phasing of the assembly with short reads, long reads and linked reads from whole-genome sequencing and with short reads from 31,719 BAC clones, thereby achieving phased blocks with an N50 size of 11.6 Mb. Haplotigs assembled from single-molecule real-time reads assigned to haplotypes on phased blocks covered 89% of genes. The haplotigs accurately characterized the hypervariable major histocompatability complex region as well as demonstrating allele configuration in clinically relevant genes such as CYP2D6. This work presents the most contiguous diploid human genome assembly so far, with extensive investigation of unreported and Asian-specific structural variants, and high-quality haplotyping of clinically relevant alleles for precision medicine.

Sphingomyelin synthase 1 mediates hepatocyte pyroptosis to trigger non-alcoholic steatohepatitis.

OBJECTIVE: Lipotoxic hepatocyte injury is a primary event in non-alcoholic steatohepatitis (NASH), but the mechanisms of lipotoxicity are not fully defined. Sphingolipids and free cholesterol (FC) mediate hepatocyte injury, but their link in NASH has not been explored. We examined the role of free cholesterol and sphingomyelin synthases (SMSs) that generate sphingomyelin (SM) and diacylglycerol (DAG) in hepatocyte pyroptosis, a specific form of programmed cell death associated with inflammasome activation, and NASH. DESIGN: Wild-type C57BL/6J mice were fed a high fat and high cholesterol diet (HFHCD) to induce NASH. Hepatic SMS1 and SMS2 expressions were examined in various mouse models including HFHCD-fed mice and patients with NASH. Pyroptosis was estimated by the generation of the gasdermin-D N-terminal fragment. NASH susceptibility and pyroptosis were examined following knockdown of SMS1, protein kinase Cδ (PKCδ), or the NLR family CARD domain-containing protein 4 (NLRC4). RESULTS: HFHCD increased the hepatic levels of SM and DAG while decreasing the level of phosphatidylcholine. Hepatic expression of Sms1 but not Sms2 was higher in mouse models and patients with NASH. FC in hepatocytes induced Sms1 expression, and Sms1 knockdown prevented HFHCD-induced NASH. DAG produced by SMS1 activated PKCδ and NLRC4 inflammasome to induce hepatocyte pyroptosis. Depletion of Nlrc4 prevented hepatocyte pyroptosis and the development of NASH. Conditioned media from pyroptotic hepatocytes activated the NOD-like receptor family pyrin domain containing 3 inflammasome (NLRP3) in Kupffer cells, but Nlrp3 knockout mice were not protected against HFHCD-induced hepatocyte pyroptosis. CONCLUSION: SMS1 mediates hepatocyte pyroptosis through a novel DAG-PKCδ-NLRC4 axis and holds promise as a therapeutic target for NASH.

Determinants of Functional Independence or Its Loss following Subthalamic Nucleus Stimulation in Parkinson's Disease.

OBJECTIVE: This study aimed to describe the change in functional status following bilateral subthalamic nucleus stimulation (STN-DBS) in Parkinson's disease (PD) and to identify predictors of postoperative functional dependence. METHODS: We included PD patients with bilateral STN-DBS who had complete Schwab & England Activities of Daily Living (S&E ADL) Scale data at baseline and 6 months after surgery from our prospective registry. Functional dependence was defined as an S&E ADL score of less than 80%. All data were collected from the on-medication state and on-stimulation state (after surgery). Logistic regression analyses were performed to determine the factors predictive of functional dependence after surgery. RESULTS: A total of 196 patients were included. At baseline, 41 patients were functionally dependent and the other 155 were functionally independent. Among the patients with preoperative dependence, 32 (78%) became functionally independent after surgery, and this conversion was associated with a lower baseline axial score (p = 0.012). Among the patients with preoperative independence, 21 (14%) developed postoperative dependence, and this conversion was associated with a higher baseline axial score (p = 0.013) and its smaller improvement (p < 0.001). Female sex (odds ratio [OR] 3.214; 95% confidence interval [CI] 1.210-8.542; p = 0.019) and a higher baseline axial score (OR 1.184; 95% CI 1.056-1.327; p = 0.004) significantly predicted the risk of postoperative functional dependence. CONCLUSIONS: We found that functional status following bilateral STN-DBS is closely related to preoperative axial symptoms. When loss of independence is a potential target for STN-DBS, clinicians should take into consideration the severity of axial impairment before surgery.

Sleep Related Problems as a Nonmotor Symptom of Dentatorubropallidoluysian Atrophy.

Dentatorubropallidoluysian atrophy (DRPLA) is a neurodegenerative disease caused by an expansion of a cytosine-adenine-guanine (CAG) repeat encoding a polyglutamine tract in the atrophin-1 protein. Unlike other CAG repeat diseases, sleep related problems have not been reported in patients with DRPLA. There was a 65-year-old man and his family with DRPLA. They suffered from seizure, gait disturbance, and cognitive decline. The patients commonly showed dream enacting sleep disorder, insomnia. The results from overnight polysomnography showed rapid eye movement (REM) without atonia in patients with DRPLA. The man died 2 years after diagnosis and was subjected for brain autopsy. We report REM sleep behavior disorders in patients with DRPLA confirmed with polysomnography with pathological description of the patient.

The Prevalence of Cerebral Microbleeds in Non-Demented Parkinson's Disease Patients.

BACKGROUND: Cerebral microbleeds (CMBs) are associated with cerebrovascular risk factors and cognitive dysfunction among patients with Parkinson's disease (PD). However, whether CMBs themselves are associated with PD is to be elucidated. METHODS: We analyzed the presence of CMBs using 3-Tesla brain magnetic resonance imaging in non-demented patients with PD and in age-, sex-, and hypertension-matched control subjects. PD patients were classified according to their motor subtypes: tremor-dominant, intermediate, and postural instability-gait disturbance (PIGD). Other cerebrovascular risk factors and small vessel disease (SVD) burdens were also evaluated. RESULTS: Two-hundred and five patients with PD and 205 control subjects were included. The prevalence of CMBs was higher in PD patients than in controls (16.1% vs. 8.8%; odds ratio [OR], 2.126; P = 0.019); CMBs in the lobar area showed a significant difference between PD patients and controls (11.7% vs. 5.9%; OR, 2.234; P = 0.032). According to the motor subtype, CMBs in those with PIGD type showed significant difference from controls with respect to the overall brain area (21.1% vs. 8.9%; OR, 2.759; P = 0.010) and lobar area (14.6% vs. 4.9%; OR, 3.336; P = 0.016). Among PD patients, those with CMBs had higher age and more evidence of SVDs than those without CMBs. CONCLUSION: We found that CMBs are more frequent in PD patients than in controls, especially in those with the PIGD subtype and CMBs on the lobar area. Further study investigating the pathogenetic significance of CMBs is required.

Validation of the Korean Version of the Scales for Outcomes in Parkinson's Disease-Sleep.

BACKGROUND: Sleep problems commonly occur in patients with Parkinson's disease (PD), and are associated with a lower quality of life. The aim of the current study was to translate the English version of the Scales for Outcomes in Parkinson's Disease-Sleep (SCOPA-S) into the Korean version of SCOPA-S (K-SCOPA-S), and to evaluate its reliability and validity for use by Korean-speaking patients with PD. METHODS: In total, 136 patients with PD from 27 movement disorder centres of university-affiliated hospitals in Korea were enrolled in this study. They were assessed using SCOPA, Hoehn and Yahr Scale (HYS), Unified Parkinson's Disease Rating Scale (UPDRS), Parkinson's Disease Sleep Scale 2nd version (PDSS-2), Non-motor Symptoms Scale (NMSS), Montgomery Asberg Depression Scale (MADS), 39-item Parkinson's Disease Questionnaire (PDQ39), Neurogenic Orthostatic Hypotension Questionnaire (NOHQ), and Rapid Eye Movement Sleep Behaviour Disorder Questionnaire (RBDQ). The test-retest reliability was assessed over a time interval of 10-14 days. RESULTS: The internal consistency (Cronbach's α-coefficients) of K-SCOPA-S was 0.88 for nighttime sleep (NS) and 0.75 for daytime sleepiness (DS). Test-retest reliability was 0.88 and 0.85 for the NS and DS, respectively. There was a moderate correlation between the NS sub-score and PDSS-2 total score. The NS and DS sub-scores of K-SCOPA-S were correlated with motor scale such as HYS, and non-motor scales such as UPDRS I, UPDRS II, MADS, NMSS, PDQ39, and NOHQ while the DS sub-score was with RBDQ. CONCLUSION: The K-SCOPA-S exhibited good reliability and validity for the assessment of sleep problems in the Korean patients with PD.

Neurological Complications Resulting from Non-Oral Occupational Methanol Poisoning.

Methanol poisoning results in neurological complications including visual disturbances, bilateral putaminal hemorrhagic necrosis, parkinsonism, cerebral edema, coma, or seizures. Almost all reported cases of methanol poisoning are caused by oral ingestion of methanol. However, recently there was an outbreak of methanol poisoning via non-oral exposure that resulted in severe neurological complications to a few workers at industrial sites in Korea. We present 3 patients who had severe neurological complications resulting from non-oral occupational methanol poisoning. Even though initial metabolic acidosis and mental changes were improved with hemodialysis, all of the 3 patients presented optic atrophy and ataxia or parkinsonism as neurological complications resulting from methanol poisoning. In order to manage it adequately, as well as to prevent it, physicians should recognize that methanol poisoning by non-oral exposure can cause neurologic complications.

Loss of Nigral Hyperintensity on 3 Tesla MRI of Parkinsonism: Comparison With (123) I-FP-CIT SPECT.

BACKGROUND: The aim of this study was to investigate whether 3 Tesla susceptibility-weighted imaging can detect the alteration of substantia nigra hyperintensity in Parkinson's disease (PD), multiple system atrophy (MSA), and progressive supranuclear palsy (PSP) and to assess the concordance between the loss of nigral hyperintensity on 3 Tesla susceptibility-weighted imaging and the nigrostriatal dopaminergic degeneration indicated by (123) I-2ß-carbomethoxy-3ß-(4-iodophenyl)-N-(3-fluoropropyl)-nortropane single photon emission computerized tomography. METHODS: Consecutive subjects with suspected parkinsonism were included, and clinical diagnosis was solidified during clinical follow-up. Two blinded neuroradiologists interpreted the nigral hyperintensity on susceptibility-weighted imaging. The performance of susceptibility-weighted imaging for detection of nigral hyperintensity loss was estimated on the basis of the clinical diagnosis and compared with single photon emission computerized tomography results. RESULTS: The study included 210 subjects (126 PD, 11 MSA, 11 PSP patients, 26 healthy controls, 36 disease controls). The presence or absence of nigral hyperintensity was accurately visualized in 112 PD, 7 MSA, and 11 PSP patients and 53 controls. We identified 16 false-negative cases and 11 false-positive cases. The sensitivity and specificity of susceptibility-weighted imaging were 88.8% and 83.6%, respectively. The concordance rate between susceptibility-weighted imaging and single photon emission computerized tomography was 86.2%. CONCLUSIONS: The loss of nigral hyperintensity on susceptibility-weighted imaging suggested nigrostriatal dopaminergic degeneration in a large portion of patients with parkinsonism, which was indicated by (123) I-2ß-carbomethoxy-3ß-(4-iodophenyl)-N-(3-fluoropropyl)-nortropane single photon emission computerized tomography. In consideration of false-negative and -positive cases, well-designed imaging protocols should be introduced to improve the performance of nigral hyperintensity imaging. © 2016 International Parkinson and Movement Disorder Society.

Perverted Head-Shaking and Positional Downbeat Nystagmus in Essential Tremor.

Even though the pathophysiology is not completely understood, cerebellar dysfunction has been invoked in essential tremor (ET). We evaluated cerebellar dysfunction in ET with the presence of perverted head-shaking (pHSN) and positional downbeat nystagmus (pDBN) which are known to reflect cerebellar dysfunction. First, we reviewed the videooculography (VOG) of 185 patients with ET from March 2007 to April 2010. Seventeen of 28 patients with pHSN and pDBN were followed up for at least a 1.8-year interval from baseline to determine the clinical course. And then, we recruited 52 consecutive patients with ET and compared their ocular motor findings with 51 normal controls using VOG. Among the 185 patients with ET, 28 (15.1 %) showed pHSN (n = 23, 12.4 %) or pDBN (n = 8, 4.3 %). Seventeen of them who were followed up did not develop Parkinsonism or other neurologic deficits during the observation period. The subsequent case-control study showed a higher prevalence of pHSN or pDBN (11/52, 21.2 %, pHSN in nine and pDBN in five) in patients with ET than in the normal controls (2/51, 3.9 %, pHSN only, P = 0.015). The tremor rating scale or involved body sites did not differ between the patients with and without pHSN/pDBN. pHSN and pDBN were more common in patients with ET than in the normal controls. This result supports that cerebellar dysfunction is associated with ET.

Accuracy of sagittal oblique view in preoperative indirect magnetic resonance arthrography for diagnosis of tears involving the upper third of the subscapularis tendon.

BACKGROUND: The purpose of this study was to investigate the accuracy of sagittal oblique view (SOV) magnetic resonance imaging grading for tears involving the upper third of the subscapularis tendons in correlation with arthroscopic findings. We also propose a schematic classification in the SOV for upper-third subscapularis tears. METHODS: The study analyzed 364 patients with an average age of 56.0 years. All patients underwent indirect magnetic resonance arthrography (MRA) before surgery. A slightly different magnetic resonance grading was introduced with SOV by musculoskeletal radiologists (Y.C.Y. and J.Y.Y.) and an orthopedic shoulder surgeon (H.Y.R.) who had no information about the clinical data. Subscapularis tendon tear classifications were all prospectively analyzed. Magnetic resonance grading was compared with the arthroscopic findings. RESULTS: The sensitivity, specificity, and accuracy of subscapularis tendon tear detection were 0.72, 0.77, and 0.75, respectively, for the radiologists. For the orthopedic surgeon, the corresponding values were 0.73, 0.83, and 0.79, respectively. The κ coefficients for interobserver agreement comparing magnetic resonance grade of the musculoskeletal radiologists with the arthroscopic grading showed fair values (κ value, 0.301). Interobserver agreement between the magnetic resonance grade of the orthopedic surgeon and arthroscopic grades was fair (κ value, 0.377). Interobserver agreement between the musculoskeletal radiologists and the orthopedic surgeon was moderate (κ value, 0.591). CONCLUSIONS: The accuracy of SOV indirect MRA for detecting tears was 0.75 to 0.79. Although the correlation between magnetic resonance and arthroscopic grading was only fair, for most of the magnetic resonancegrading on SOV, the first facet view showed similar results compared with arthroscopy. The accuracy of determining whether subscapularis repair is indicated was 0.82 to 0.83 with SOV indirect MRA.

Dysport and Botox at a ratio of 2.5:1 units in cervical dystonia: a double-blind, randomized study.

We aimed to compare Dysport (abobotulinumtoxinA, Ipsen Biopharm, Slough, UK) and Botox (onabotulinumtoxinA, Allergan, Irvine, CA, USA) at a 2.5:1 ratio in the treatment of cervical dystonia (CD). A Dysport/Botox ratio of lower than 3:1 was suggested as a more appropriate conversion ratio, considering its higher efficacy and more frequent incidence of adverse effects not only in the treatment of CD but also in other focal movement disorders. A randomized, double-blind, multicenter, non-inferiority, two-period crossover study was done in CD, with a duration of at least 18 months. Patients were randomly assigned to treatment for the first period with Dysport or Botox, and they were followed up for 16 weeks after the injection. After a 4-week washout period, they were switched to the other formulation and then followed up for 16 weeks. The primary outcome was the changes in the Tsui scale between the baseline value and that at 1 month after each injection. A total of 103 patients were enrolled, and 94 completed the study. Mean changes in the Tsui scale between baseline and 4 weeks after each injection tended to favor Botox; however, this was not statistically significant (4.0 ± 3.9 points for the Dysport treatment vs. 4.8 ± 4.1 points for Botox; 95% confidence interval, -0.1-1.7; P = 0.091). The mean change of the Toronto western spasmodic torticollis rating scale score, the proportion of improvement in clinical global impression and patient global impression, and the incidences of adverse events were not significantly different between the two treatments. With regard to safety and efficacy, Dysport was not inferior to Botox in patients with CD at a conversion factor of 2.5:1. [clinicaltrial.gov: NCT00950664]

A highly annotated whole-genome sequence of a Korean individual.

Recent advances in sequencing technologies have initiated an era of personal genome sequences. To date, human genome sequences have been reported for individuals with ancestry in three distinct geographical regions: a Yoruba African, two individuals of northwest European origin, and a person from China. Here we provide a highly annotated, whole-genome sequence for a Korean individual, known as AK1. The genome of AK1 was determined by an exacting, combined approach that included whole-genome shotgun sequencing (27.8x coverage), targeted bacterial artificial chromosome sequencing, and high-resolution comparative genomic hybridization using custom microarrays featuring more than 24 million probes. Alignment to the NCBI reference, a composite of several ethnic clades, disclosed nearly 3.45 million single nucleotide polymorphisms (SNPs), including 10,162 non-synonymous SNPs, and 170,202 deletion or insertion polymorphisms (indels). SNP and indel densities were strongly correlated genome-wide. Applying very conservative criteria yielded highly reliable copy number variants for clinical considerations. Potential medical phenotypes were annotated for non-synonymous SNPs, coding domain indels, and structural variants. The integration of several human whole-genome sequences derived from several ethnic groups will assist in understanding genetic ancestry, migration patterns and population bottlenecks.

Meta-analysis identifies a MECOM gene as a novel predisposing factor of osteoporotic fracture.

BACKGROUND: Osteoporotic fracture (OF) as a clinical endpoint is a major complication of osteoporosis. To screen for OF susceptibility genes, we performed a genome-wide association study and carried out de novo replication analysis of an East Asian population. METHODS: Association was tested using a logistic regression analysis. A meta-analysis was performed on the combined results using effect size and standard errors estimated for each study. RESULTS: In a combined meta-analysis of a discovery cohort (288 cases and 1139 controls), three hospital based sets in replication stage I (462 cases and 1745 controls), and an independent ethnic group in replication stage II (369 cases and 560 for controls), we identified a new locus associated with OF (rs784288 in the MECOM gene) that showed genome-wide significance (p=3.59×10(-8); OR 1.39). RNA interference revealed that a MECOM knockdown suppresses osteoclastogenesis. CONCLUSIONS: Our findings provide new insights into the genetic architecture underlying OF in East Asians.

The prevalence of essential tremor in elderly Koreans.

Essential tremor (ET) is one of the most common movement disorders. The prevalence of ET varies substantially among studies. In Korea, there is no well-designed epidemiological study of the prevalence of ET. Thus, we investigated the prevalence of ET in a community in Korea. Standardized interviews and in-person neurological examinations were performed in a random sample of the elderly aged 65 yr or older. Next, movement specialists attempted to diagnose ET clinically. People who showed equivocal parkinsonian features underwent dopamine transporter imaging using [(123)I]-FP-CIT SPECT, to differentiate ET from parkinsonism. A total of 714 subjects participated in this population-based study. Twenty six of these subjects were diagnosed as having ET. The crude prevalence of ET was 3.64 per 100 persons. Age, gender, or education period were not different between the ET patients and the non-ET subjects. The prevalence of ET was slightly lower than those reported in previous studies. Further studies including more subjects are warranted.

Tibial component coverage based on bone mineral density of the cut tibial surface during unicompartmental knee arthroplasty: clinical relevance of the prevention of tibial component subsidence.

INTRODUCTION: An optimally implanted tibial component during unicompartmental knee arthroplasty would be flush with all edges of the cut tibial surface. However, this is often not possible, partly because the tibial component may not be an ideal shape or because the ideal component size may not be available. In such situations, surgeons need to decide between component overhang and underhang and as to which sites must be covered and which sites could be undercovered. The objectives of this study were to evaluate the bone mineral density of the cut surface of the proximal tibia around the cortical rim and to compare the bone mineral density according to the inclusion of the cortex and the site-specific matched evaluation. MATERIALS AND METHODS: One hundred and fifty consecutive patients (100 men and 50 women) were enrolled in this study. A quantitative computed tomography was used to determine the bone density of the cut tibial surface. Medial and lateral compartments were divided into anterior, middle, and posterior regions, and these three regions were further subdivided into two regions according to containment of cortex. The site-specific matched comparison (medial vs. lateral) of bone mineral density was performed. RESULTS: In medial sides, the mid-region, including the cortex, showed the highest bone mineral density in male and female patients. The posterior region showed the lowest bone mineral density in male patients, and the anterior and posterior regions showed the lowest bone mineral density in female patients. Regions including cortex showed higher bone mineral density than pure cancellous regions in medial sides. In lateral sides, posterior regions including cortex showed highest bone mineral density with statistical significance in both male and female patients. The anterior region showed the lowest bone mineral density in both male and female patients. CONCLUSION: The mid-region of the medial side and the posterior region of the lateral side are relatively safe without cortical coverage when the component is not flush with all edges of the tibia. Cortical coverage is strongly recommended for the prevention of subsidence of the tibial component in the posterior region of the medial side, and in the anterior region of the lateral side.

Factors influencing the decision-making process in breast reconstruction from the perspective of reconstructive surgeons: A qualitative study involving Korean plastic surgeons.

BACKGROUND: Little research has been conducted on factors influencing the decision-making process for immediate breast reconstruction (IBR) options from the perspective of reconstructive surgeons, despite its significant impact on doctor-patient communication and shared decision-making. This study aims to explore the multiple factors and the mechanisms by which they interact using a qualitative methodology. We also address potential barriers to shared decision-making in IBR. METHODS: Semistructured interviews were conducted with a purposive sample of reconstructive surgeons. Thematic analysis was used to identify key influences on IBR decision-making process from the perspective of reconstructive surgeons. RESULTS: Four major themes were identified: 1. Patient clinical scenarios; 2. Nonclinical practice environments; 3. Reconstructive surgeon preferences; and 4. Patient consultation. Reconstructive surgeons demonstrated diverse approaches to patient clinical scenarios. High-volume centers were significantly influenced by nonclinical factors such as scheduling and operating room allocation systems. Reconstructive surgeons often had strong personal preferences for specific IBR options, shaped by their expertise, experience, and clinical environment. Based on the preliminary decision, surgeons provided information with varying degrees of neutrality. Patients varied in their knowledge and participation, resulting in variation in the final decision authority among surgeons. CONCLUSIONS: This study highlights the need to address nonclinical environmental constraints to improve shared decision-making process in IBR. Surgeons should recognize power imbalances in the doctor-patient relationship and be aware of their biases.