Abnormalities of the pericruciate fat pad: Correlations with the location and severity of chondral lesions of the knee.

PURPOSE: The aim of this study was to evaluate the relationship between the grade of signal change of the pericruciate fat pad (PCFP) and the location and severity of cartilage alterations in the knee on magnetic resonance imaging (MRI). MATERIALS AND METHODS: This retrospective study included 234 patients (M:F = 96:138, mean: 51 years) who underwent knee MRI. Two experienced musculoskeletal radiologists assessed any PCFP alterations (as grades 0-3) and chondral lesions using the modified Outerbridge grade (as grades 0-4). Bone marrow lesions (BMLs), meniscal status, anterior cruciate ligament alterations, and effusion-synovitis were also evaluated on the MRI. The relationships between PCFP alteration and MR findings (including the grade of chondral lesion) were evaluated. RESULTS: Signal changes in the PCFP were detected in 150 cases by Reader 1 (grade 0, 67 cases; grade 1, 53 cases; grade 2, 21 cases; grade 3, 9 cases) and in 154 cases by Reader 2 (grade 0, 59 cases; grade 1, 61 cases; grade 2, 24 cases; grade 3, 10 cases). The grade of PCFP signal change was statistically significantly correlated with the grade of the chondral lesion of the medial femoral condyle (MFC) (p = 0.029 and p = 0.003, respectively) and the medial tibial plateau (MTP) (p = 0.045, p = 0.002, Readers 1 and 2, respectively). The grade of PCFP signal change was significantly correlated with the grade of the BMLs of the MFC, MTP, and lateral femoral condyle (p < 0.05) for both readers. PCFP alteration was related to effusion-synovitis and tears of the medial meniscus. CONCLUSIONS: The grade of PCFP signal change was correlated with the severity of the cartilage alteration in the medial compartment of the knee joint and was also correlated with BMLs in the medial compartment, medial meniscal tears, and synovitis. Therefore, signal change in the PFCP seen on MRI can be an additional clue of the presence of osteoarthritis in the knee, particularly in the medial compartment.

A motif in the 5'untranslated region of messenger RNAs regulates protein synthesis in a S6 kinase-dependent manner.

The 5' untranslated regions (UTRs) in messenger RNAs (mRNAs) play an important role in the regulation of protein synthesis. We had previously identified a group of mRNAs that includes human semaphorin 7A (SEMA7A) whose translation is upregulated by the Erk/p90S6K pathway in human eosinophils, with a potential negative impact in asthma and airway inflammation. In the current study, we aimed to find a common 5'UTR regulatory cis-element, and determine its impact on protein synthesis. We identified a common and conserved 5'UTR motif GGCTG-[(C/G)T(C/G)]n-GCC that was present in this group of mRNAs. Mutations of the first two GG bases in this motif in SEMA7A 5'UTR led to a complete loss of S6K activity dependence for maximal translation. In conclusion, the newly identified 5'UTR motif present in SEMA7A has a critical role in regulating S6K-dependent protein synthesis.

Aponeurotic expansion of the supraspinatus tendon and concomitant shoulder pathologies.

OBJECTIVES: We investigated the correlation of aponeurotic expansion of the supraspinatus tendon (AESST) with shoulder pathologies such as long head of biceps tendon (LHB), supraspinatus tendon (SST), and subscapularis tendon (SSc). METHODS: We retrospectively evaluated 47 healthy patients and 163 patients with shoulder symptoms from August 2014 to March 2021. First, the presence of AESST was evaluated based on Moser et al.'s classification. Second, the presence of abnormal findings of including LHB tendinitis, LHB subluxation, SST tendinitis, SST tear, SSc tendinitis, and SSc tendon tear was evaluated. We analyzed the prevalence and type of AESST between the two study groups and the relationship between abnormal findings and the presence of AESST. RESULTS: The prevalence of AESST for readers 1 and 2 was 26.1% and 30.4% in the asymptomatic group, respectively, and 22.8% and 31.3% in the symptomatic group. Type 1 was most common (17.3-23.9%) followed by types 2a and 2b. There were no significant differences in the distribution of aponeurosis type between the two groups. In the AESST-positive groups, 45.9% and 47.1% had SST tears on examination by readers 1 and 2, respectively, whereas only 26.4% and 27.9% had SST tears in the AESST-negative group suggesting AESST is associated with SST tear. The odds ratio for SST tear in the presence of AESST was 2.370 and 2.294 (readers 1 and 2). CONCLUSIONS: There is an association between SST tears and the presence of AESST. KEY POINTS: • We evaluated the prevalence of aponeurotic expansion of the supraspinatus tendon (AESST) on MR imaging by type in both symptomatic and asymptomatic groups. • We investigated the correlation of AESST with shoulder pathologies such as biceps tendon and supraspinatus tendon tears. • There is an association between SST tears and the presence of AESST. • Radiologists should be aware of the risk of rotator cuff pathology if AESST is detected.

The reproducibility of shear wave and strain elastography in epidermal cysts.

PURPOSE: This study evaluated epidermal cyst elasticity using multiple parameters of strain elastography (SE) and shear wave elastography (SWE) and assessed the reproducibility of each parameter. METHODS: This retrospective study included 73 patients with epidermal cysts who underwent SE and SWE. SE scores were classified as 1-4 according to elasticity. The strain ratio was evaluated using the elasticity ratio of lesions and adjacent subcutaneous fat tissue. For SWE, the shear wave velocity (m/s), elasticity (kPa) according to the Young modulus, velocity ratio, and elasticity ratio were evaluated. All values were measured twice. The reproducibility of SE and SWE measurements was assessed. The relationships among SE and SWE measurements were evaluated. RESULTS: The strain ratio on SE images showed good reproducibility (intra-class correlation coefficient [ICC]=0.789), and SE scores showed substantial reproducibility (kappa=0.753 and kappa=0.758 for readers 1 and 2, respectively). Moderate reproducibility was found for shear wave velocity and elasticity (ICC=0.750 and ICC=0.648, respectively), as well as for the shear wave velocity of the reference tissue and velocity ratio (ICC=0.747 and ICC=0.713, respectively). All SE scores were positively correlated with the strain ratio (P<0.001). The strain ratio in the second SE session was significantly correlated with the elasticity ratio and velocity ratio in the first SWE session (r=0.245, P=0.037; r=0.243, P=0.038, respectively). Other variables were not correlated. CONCLUSION: SE and SWE parameters of epidermal cysts showed moderate to good reproducibility. The strain ratio on SE showed good reproducibility and could provide relatively objective and consistent measurements of epidermal cyst elasticity.

Factors of Hospitals Associated With an Independent Hospice Care Unit: A Quantitative Empirical Study.

Few studies have examined why some hospitals operate independent hospice units (IHUs) and others do not. This study aims to investigate the organizational factors of hospitals having IHU. The units of analysis were individual hospitals. The study had a cross-sectional design and used health insurance claims data of 349 hospitals in Korea from January 1 to December 31, 2019. The dependent variable was whether a hospital operated an IHU. The independent variables were the percentage of patients with cancer, overall severity of patients, percentage of patients 60 years and older, health care cost per patient, percentage of inpatients, and nurse staffing level. Independent hospice units were present at 21.2% of the hospitals (74/349). The odds of having an IHU were significantly associated with the following factors: the percentage of patients with cancer (odds ratio [OR], 1.228; 95% confidence interval [CI], 1.071-1.408; P = .003), disease severity (OR, 5.129; 95% CI, 2.477-10.622; P < .001), percentage of patients 60 years and older (OR, 1.053; 95% CI, 1.015-1.092; P = .006), health care cost per patient (OR, 1.018; 95% CI, 1.009-1.027; P < .001), and nurse staffing level (OR, 0.439; 95% CI, 0.292-0.661; P < .001). The organizational factors of hospitals operating IHUs were similar to those of hospice facilities.

Multispectral image fusion based pedestrian detection using a multilayer fused deconvolutional single-shot detector.

Recent research has demonstrated that effective fusion of multispectral images (visible and thermal images) enables robust pedestrian detection under various illumination conditions (e.g., daytime and nighttime). However, there are some open problems such as poor performance in small-sized pedestrian detection and high computational cost of multispectral information fusion. This paper proposes a multilayer fused deconvolutional single-shot detector that contains a two-stream convolutional module (TCM) and a multilayer fused deconvolutional module (MFDM). The TCM is used to extract convolutional features from multispectral input images. Then fusion blocks are incorporated into the MFDM to combine high-level features with rich semantic information and low-level features with detailed information to generate features with strong a representational power for small pedestrian instances. In addition, we fuse multispectral information at multiple deconvolutional layers in the MFDM via fusion blocks. This multilayer fusion strategy adaptively makes the most use of visible and thermal information. In addition, using fusion blocks for multilayer fusion can reduce the extra computational cost and redundant parameters. Empirical experiments show that the proposed approach achieves an 81.82% average precision (AP) on a new small-sized multispectral pedestrian dataset. The proposed method achieves the best performance on two well-known public multispectral datasets. On the KAIST multispectral pedestrian benchmark, for example, our method achieves a 97.36% AP and a 20 fps detection speed, which outperforms the state-of-the-art published method by 6.82% in AP and is three times faster in its detection speed.

A New Deep Learning Based Multi-Spectral Image Fusion Method.

In this paper, we present a new effective infrared (IR) and visible (VIS) image fusion method by using a deep neural network. In our method, a Siamese convolutional neural network (CNN) is applied to automatically generate a weight map which represents the saliency of each pixel for a pair of source images. A CNN plays a role in automatic encoding an image into a feature domain for classification. By applying the proposed method, the key problems in image fusion, which are the activity level measurement and fusion rule design, can be figured out in one shot. The fusion is carried out through the multi-scale image decomposition based on wavelet transform, and the reconstruction result is more perceptual to a human visual system. In addition, the visual qualitative effectiveness of the proposed fusion method is evaluated by comparing pedestrian detection results with other methods, by using the YOLOv3 object detector using a public benchmark dataset. The experimental results show that our proposed method showed competitive results in terms of both quantitative assessment and visual quality.

New Dark Area Sensitive Tone Mapping for Deep Learning Based Traffic Sign Recognition.

In this paper, we propose a new Intelligent Traffic Sign Recognition (ITSR) system with illumination preprocessing capability. Our proposed Dark Area Sensitive Tone Mapping (DASTM) technique can enhance the illumination of only dark regions of an image with little impact on bright regions. We used this technique as a pre-processing module for our new traffic sign recognition system. We combined DASTM with a TS detector, an optimized version of YOLOv3 for the detection of three classes of traffic signs. We trained ITSR on a dataset of Korean traffic signs with prohibitory, mandatory, and danger classes. We achieved Mean Average Precision (MAP) value of 90.07% (previous best result was 86.61%) on challenging Korean Traffic Sign Detection (KTSD) dataset and 100% on German Traffic Sign Detection Benchmark (GTSDB). Result comparisons of ITSR with latest D-Patches, TS detector, and YOLOv3 show that our new ITSR significantly outperforms in recognition performance.

Pharmacological target therapy of neuropathic pain and patient-reported outcomes in patients with chronic low back pain in Korea: Results from the NLBP Outcomes Research.

A number of studies have demonstrated an association of neuropathic pain and chronic low back pain (CLBP), but the outcome difference in each medical management is poorly understood. This study is aimed to investigate treatment patterns of neuropathic pain in CLBP patients and to explore patient-reported outcomes (PROs) including quality of life (QoL) and functional disability by treatment patterns.Data were extracted from the neuropathic low back pain (NLBP) outcomes research. It was a multicenter and cross-sectional study in which 1200 patients were enrolled at 27 general hospitals, from 2014 to 2015. Of total, 478 patients classified as neuropathic pain were used for this subgroup analysis. The patients were divided into 2 groups according to treatment patterns (with vs. without the targeted therapy [TT] of neuropathic pain). Demographic and clinical features were collected by chart reviews and PROs were measured by patient's survey. QoL was assessed by EuroQoL 5-dimension (EQ-5D) questionnaire. Functional disability was measured by the Quebec Back Pain Disability Scale (QBPDS). Multiple linear regression analyses were conducted to compare the PROs between TT group and non-targeted therapy (nTT) group.Among the NLBP patients (mean age 63years, female 62%), EQ-5D index, EuroQoL-Visual Analog Scale (EQ-VAS), and QBPDS Scores (mean ±â€Šstandard deviation) were 0.40 ±â€Š0.28, 54.98 ±â€Š19.98, and 46.03 ±â€Š21.24, respectively. Only 142 (29.7%) patients had pharmacological TT of neuropathic pain. Univariate analyses revealed no significant mean differences between TT group and nTT group in the EQ-5D index (0.41 ±â€Š0.27 and 0.39 ±â€Š0.28), EQ-VAS (56.43 ±â€Š18.17 and 54.37 ±â€Š20.69), and QBPDS (45.31 ±â€Š21.32 and 46.31 ±â€Š21.24). After adjustment with covariates, TT group had higher scores of EQ-5D index (ß = 0.07; P < 0.01) and EQ-VAS (ß = 4.59; P < 0.05) than the nTT group. The TT group's QBPDS score was lower than the nTT group, although its statistical significance still has not been reached (ß = -4.13; P = 0.07).We found that considerable proportion of the NLBP patients remains untreated or undertreated. Although TT group had significantly better QoL than nTT group, only 29.7% of NLBP patients had pharmacological TT. Therefore, clinicians should consider using TT for better QoL of neuropathic pain patients.

Prevalence of Neuropathic Pain and Patient-Reported Outcomes in Korean Adults with Chronic Low Back Pain Resulting from Neuropathic Low Back Pain.

STUDY DESIGN: A noninterventional, multicenter, cross-sectional study. PURPOSE: We investigated the prevalence of neuropathic pain (NP) and patient-reported outcomes (PROs) of the quality of life (QoL) and functional disability in Korean adults with chronic low back pain (CLBP). OVERVIEW OF LITERATURE: Among patients with CLBP, 20%-55% had NP. METHODS: Patients older than 20 years with CLBP lasting for longer than three months, with a visual analog scale (VAS) pain score higher than four, and with pain medications being used for at least four weeks before enrollment were recruited from 27 general hospitals between December 2014 and May 2015. Medical chart reviews were performed to collect demographic/clinical features and diagnosis of NP (douleur neuropathique 4, DN4). The QoL (EuroQoL 5-dimension, EQ-5D; EQ-VAS) and functional disability (Quebec Back Pain Disability Scale, QBPDS) were determined through patient surveys. Multiple linear regression analyses were performed to compare PROs between the NP (DN4≥4) and non-NP (DN4<4) groups. RESULTS: A total of 1,200 patients (females: 65.7%; mean age: 63.4±13.0 years) were enrolled. The mean scores of EQ-5D, EQ-VAS, and QBPDS were 0.5±0.3, 55.7±19.4, and 40.4±21.1, respectively. Among all patients, 492 (41.0%; 95% confidence interval, 38.2%-43.8%) suffered from NP. The prevalence of NP was higher in male patients (46.8%; p<0.01), in patients who had pain based on radiological and neurological findings (59.0%; p<0.01), and in patients who had severe pain (49.0%; p<0.01). There were significant mean differences in EQ-5D (NP group vs. non-NP group: 0.4±0.3 vs. 0.5±0.3; p<0.01) and QBPDS (NP group vs. non-NP group: 45.8±21.2 vs. 36.3±20.2; p<0.01) scores. In the multiple linear regression, patients with NP showed lower EQ-5D (ß=-0.1; p<0.01) and higher QBPDS (ß=7.0; p<0.01) scores than those without NP. CONCLUSIONS: NP was highly prevalent in Korean patients with CLBP. Patients with CLBP having NP had a lower QoL and more severe dysfunction than those without NP. To enhance the QoL and functional status of patients with CLBP, this study highlights the importance of appropriately diagnosing and treating NP.

Inter- and Intra-Observer Variability of the Volume of Cervical Ossification of the Posterior Longitudinal Ligament Using Medical Image Processing Software.

OBJECTIVE: Computed tomography (CT)-based method of three dimensional (3D) analysis (MIMICS®, Materialise, Leuven, Belgium) is reported as very useful software for evaluation of OPLL, but its reliability and reproducibility are obscure. This study was conducted to evaluate the accuracy of MIMICS® system, and inter- and intra-observer reliability in the measurement of OPLL. METHODS: Three neurosurgeons independently analyzed the randomly selected 10 OPLL cases with medical image processing software (MIMICS®) which create 3D model with Digital Imaging and Communication in Medicine (DICOM) data from CT images after brief explanation was given to examiners before the image construction steps. To assess the reliability of inter- and intra-examiner intraclass correlation coefficient (ICC), 3 examiners measured 4 parameters (volume, length, width, and length) in 10 cases 2 times with 1-week interval. RESULTS: The inter-examiner ICCs among 3 examiners were 0.996 (95% confidence interval [CI], 0.987-0.999) for volume measurement, 0.973 (95% CI, 0.907-0.978) for thickness, 0.969 (95% CI, 0.895-0.993) for width, and 0.995 (95% CI, 0.983-0.999) for length. The intra-examiner ICCs were 0.994 (range, 0.991-0.996) for volume, 0.996 (range, 0.944-0.998) for length, 0.930 (range, 0.873-0.947) for width, and 0.987 (range, 0.985-0.995) for length. CONCLUSION: The medical image processing software (MIMICS®) provided detailed quantification OPLL volume with minimal error of inter- and intra-observer reliability in the measurement of OPLL.

Interreader Reliability and Clinical Validity of a Magnetic Resonance Imaging Grading System for Cervical Foraminal Stenosis.

OBJECTIVE: Park system is a magnetic resonance imaging (MRI) grading system for cervical neural foraminal stenosis (CNFS) and consists of 4 grades (0-3) based on the foraminal shape of 45-degree T2-weighted oblique sagittal images. The objective of this study was to evaluate the interreader reliability of the Park system among radiologists, residents, and clinicians. This study also assessed the correlations between radiologic and clinical findings. MATERIAL AND METHODS: A total of 289 patients (men:women = 155:134, mean age = 50 years) who underwent oblique sagittal MRI of the cervical spine at our hospital were included. According to the MR grading system suggested by Park et al (Br J Radiol 2013;86:20120515), 2 radiologists, 2 trainees, and 2 clinicians measured CNFS grade at the most narrow point. A neurosurgeon assessed the associated clinical manifestations. κ statistics were used to analyze the interreader agreement among the radiologists and clinicians. The clinical correlations between grade and positive clinical manifestations were assessed with R using nonparametric correlation analysis (Spearman correlation). RESULTS: The overall interreader agreements between radiologists, between trainees, between clinicians, and between radiologists and clinicians were almost perfect (κ = 0.80-0.96). There were moderate correlations between grade and clinical manifestations in each group (R = 0.562-0.669). There were moderate to relatively high correlations between grade and neurologic manifestations based on cervical level (R = 0.570-0.715) (all P < 0.05). CONCLUSIONS: Regardless of reader experience, there was substantial to almost perfect interreader reliability with the Park system for CNFS based on oblique sagittal MRI.

Comparison of two MR grading systems for correlation between grade of cervical neural foraminal stenosis and clinical manifestations.

OBJECTIVE: To compare the reliability of two recently reported MR grading systems of cervical neural foraminal stenosis (CNFS) and their correlation with clinical manifestations. METHODS: We evaluated 188 patients (male : female = 80 : 108; mean age of 41 years) who visited our institution and underwent oblique sagittal MRI of the cervical spine. Two radiologists evaluated the MRI findings for the presence and grade of CNFS at the narrowest point, with the grading systems (Park, Kim and mKim systems) suggested by Park et al and Kim et al. More than one positive neurologic sign and more than one neurologic clinical symptom was considered a positive neurologic manifestation of each foraminal stenosis. Interobserver agreement between the two readers was analyzed using kappa statistics. Non-parametric correlation analysis (Spearman's correlation) was used to evaluate the correlation coefficients (R) to assess the relationship between CNFS grade and clinical manifestations. RESULTS: Both the Park and mKim systems demonstrated a relatively high correlation (R = 0.714-0.764) between the CNFS grade and clinical manifestation, while the Kim system yielded a moderate correlation (by Reader 2). The Park and mKim systems demonstrated higher correlation values at the level of C6-7 than C4-5, while the Kim system showed no difference in correlation at the cervical spine level. CONCLUSION: Both the Park and mKim systems provide a reliable, reproducible CNFS diagnosis, while the Kim system has a slightly inferior reliability. The Park and mKim systems had a similar, relatively high clinical correlation. ADVANCES IN KNOWLEDGE: Grades 2 and 3 of the Park system and Grade 2 in the Kim and mKim systems exhibited a similar clinical significance. Patients with a grade of 0 (using each system) consistently exhibit negative neurologic manifestation.

Treatment of Polyostotic Fibrous Dysplasia of the Thoracic Spine with Intravenous Pamidronate: Result from 9 Months Follow Up.

Fibrous dysplasia of the spine is very rarely observed. We reported a case of a 57-year-old woman, who presented with neck and bilateral shoulder pain with histologically confirmed fibrous dysplasia, involving the first and second thoracic vertebrae. Clinical and radiological findings were not specific for fibrous dysplasia. The histological biopsy was required for a confirmed diagnosis. Endocrine and metabolic evaluations are required to rule out diseases such as hyperthyroidism, Cushing syndrome and osteomalacia. Fibrous dyplasia can be managed by appropriate medical and surgical treatments based on the patient's neurological status and symptoms. Our patient was given intravenous pamidronate 60mg/day for 3 days. After 9 months, her initial symptoms were improved, but computed tomography scan of the thoracic spine showed no change of the lesions.

Two mechanisms for putrescine-dependent transcriptional expression of the putrescine aminotransferase gene, ygjG, in Escherichia coli.

In this study, on evaluating the physiological function and mechanism of putrescine, we found that putrescine supplementation (1 mM) increases transcription of the putrescine aminotransferase gene, ygjG. Putrescine-dependent expression was confirmed by measuring ß-galactosidase activity and with reverse transcription-polymerase chain reaction. To understand the role of putrescine in ygjG expression, we genetically characterized and found that a knockout mutation in an alternative sigma factor, rpoS, abolished putrescine-dependent ygjG-lacZ expression. In the rpoS mutant, RpoS overexpression complemented the mutant phenotype. However, RpoS overexpression induced ygjG-lacZ expression with putrescine supplementation but not without supplementation. We also found that the loss of putrescine-dependent ygjG-lacZ expression induced by rpoS was completely restored under nitrogen-starvation conditions. The putrescine-dependent expression of ygjG-lacZ under this condition was clearly dependent on another alternative sigma factor, rpoN, and its cognate activator ntrC. These results show that rpoS is required for putrescine-dependent ygjG-lacZ expression, but the effect of putrescine on this expression is not caused by simple modulation of RpoS synthesis. Putrescine-dependent expression of ygjG-lacZ was controlled by at least two sigma factors: rpoS under excess nitrogen conditions and rpoN under nitrogen-starvation conditions. These results suggest that putrescine plays an important role in the nitrogen regulation system.

Thoracolumbar extradural arachnoid cysts: a study of 14 consecutive cases.

BACKGROUND: To investigate characteristic clinical and radiological features of extradural arachnoid cysts (EDACs) in the thoracolumbar region, a retrospective review of medical records and imaging studies was performed. EDACs are well known but relatively rare lesions in the thoracolumbar spinal canal. The most common site is the lower thoracic spine, and it may cause neurological symptoms by compressing the spinal cord or nerve root. In this study, the pathogenesis, symptomatology, diagnostic approach, and surgical management of EDACs will be discussed. METHODS: We studied 14 consecutive patients who were surgically treated for EDACs in the thoracolumbar region at our institute between March 2000 and January 2011. The history, clinical presentations, image findings, operative findings, and surgical outcomes of these patients were retrospectively analyzed. The mean follow-up period was 28 months (range: 6-72 months). RESULTS: Progressive motor weakness was the predominant symptom in all patients. Nine patients had radicular leg pain and back pain in the thoracolumbar area. On MRI, the cyst compressed the dural sac and spinal cord posteriorly typically with bilateral foraminal extensions. On radiological study, a communication point with the subarachnoid was hardly observed. The surgical treatment of EDACs included complete resection of the walls and closing the communicating point with the subarachnoid space. All patients showed excellent outcomes according to Odom's criteria without recurrence. One CSF leakage and one postoperative hematoma were noted. CONCLUSIONS: Thoracolumbar EDAC patients presented paraparesis and leg pain. Complete excision and closing the communicating point with the subarachnoid space were the choices of treatment, and the outcomes were favorable.

The clinical features and surgical outcomes of patients with intramedullary spinal cord cavernous malformations.

BACKGROUND: Cavernous malformations (CMs) are not uncommon, but most of them are found to be located intracranially. Intramedullary CMs are rare, accounting for only 3-5% of identified total central nervous system lesions. The natural history of intramedullary CMs and their clinical features, including the risk of hemorrhage from a large series, still remains unclear and needs to be elucidated. We review our experience with surgically treated patients with intramedullary CMs and discuss the clinical features and surgical outcomes. METHODS: Between March 2004 and March 2010, a total of 21 patients with intramedullary spinal cord CMs were surgically treated in a single institution. Data from 21 patients were retrospectively analyzed. RESULTS: There were 13 females and 8 males ranging in age from 10 to 70 years (mean age 39.3 years). All patients harbored single symptomatic CM of the nervous system, and multiple lesions were not found. The annual retrospective hemorrhage rate was 2.18% per patient/year. All but one CM were completely resected, and the average follow-up period was 22.1 months (1-73 months). Ten of the 21 patients experienced an improvement in neurological state, 9 patients remained unchanged, and 2 patients experienced worsening of their conditions. CONCLUSIONS: Symptomatic intramedullary CMs should be surgically removed to avoid further neurological deterioration. Though there are some limitations due to the retrospective nature of this study and its small number of patients, the prognosis was found to be related to the preoperative neurological state and to the type of symptom presentation.

Minimally Invasive Muscle Sparing Transmuscular Microdiscectomy : Technique and Comparison with Conventional Subperiosteal Microdiscectomy during the Early Postoperative Period.

OBJECTIVE: The authors introduce a minimally invasive muscle sparing transmuscular microdiscectomy (MSTM) to treat herniated lumbar disc disease. Its results are compared with conventional subperiosteal microdiscectomy (CSM) to validate the effectiveness. METHODS: Muscle sparing transmuscular microdiscectomy, which involves muscle dissection approach using the natural fat cleavage plane between the multifidus to expose the interlaminar space, was performed in 23 patients to treat a single level unilateral lumbar radiculopathy. The creatine phosphokinase (CPK)-MM serum levels were measured on admission and at 1, 3, and 5 days postoperatively. Postoperative pain was evaluated using a 10-point visual analogue scale (VAS) and recorded on admission and at 1, 3, and 5 days postoperatively. The results were compared to those from the conventional subperiosteal microdiscectomy (43 patients). RESULTS: The CPK-MM levels were significantly lower in the serum of the MSTM group compared to the CSM group on postoperative days three and five (p = 0.03 and p = 0.02, respectively). The clinical scales for back pain using VAS were significantly lower in the MSTM group than in the CSM group on postoperative days three (p = 0.04). The mean VAS scores for leg pain in both groups showed no significant differences during the early postoperative period. CONCLUSION: Muscle sparing transmuscular microdiscectomy is a minimally invasive surgical option to treat lumbar radiculopathy due to herniated disc. The approach affected minimal injury to posterior lumbar supporting structures with alleviated postoperative back pain.