Effect of Ceftriaxone Dosage and Albumin-Bilirubin Score on the Risk of Ceftriaxone-Induced Liver Injury.

The albumin-bilirubin (ALBI) score is an index of hepatic functional reserve and is calculated from serum albumin and total bilirubin levels. However, the relationship between ceftriaxone (CTRX)-induced liver injury and ALBI score remains unknown. Therefore, we aimed to elucidate the risk of CTRX-induced liver injury based on the ALBI scores and CTRX dosage. This was a single-center, retrospective, case-control study of 490 patients and the primary outcome was CTRX-induced liver injury. We performed a COX regression analysis using age ≥75 years, male sex, alanine aminotransferase levels, ALBI score, and CTRX dosage regimen (4 ≥2 or 1 g/d) as explanatory factors. We also performed 1 : 1 propensity score matching between non-liver injury and liver injury groups. The incidence of liver injury was 10.0% (49/490). In COX regression analysis, CTRX 4 g/d was an independent risk factor for liver injury (95% coefficient interval: 1.05-6.96, p = 0.04). Meanwhile, ALBI score ≥-1.61 was an independent factor for liver injury (95% coefficient interval: 1.03-3.22, p = 0.04) with the explanatory factor of ≥2 and 1 g/d. The Kaplan-Meier curve indicated that the cumulative risk for CTRX-induced liver injury was significantly higher in the ALBI score ≥-1.61 group than in the ALBI score <-1.61 group before propensity score matching (p = 0.032); however, no significant differences were observed after propensity score matching (p = 0.791). These findings suggest that in patients treated with CTRX with ALBI score ≥-1.61, frequent liver function monitoring should be considered.

Effect of pharmacist-led intervention protocol on preventing postoperative delirium after elective cardiovascular surgery.

Postoperative delirium (PD) is an acute brain dysfunction, with a particularly high incidence after cardiovascular surgery. Pharmacist-led interventions show limited evidence in attenuating PD in cardiovascular surgery. In this retrospective cohort study, we aimed to clarify the risk factors of PD for cardiovascular surgery focused on pharmacotherapy and elucidate the effect of pharmacist-led intervention on the PD attenuation rate based on protocol-based pharmaceutical management (PBPM). This study included 142 adult patients who underwent elective valve replacement or valvuloplasty. The risk factors for PD were investigated using multivariate logistic regression analysis. Taking risk factors into consideration, a protocol was developed to discontinue benzodiazepines prescriptions by ward pharmacists, and replace with ramelteon and suvorexant if all the following factors apply: 1) number of medications ≥ 6 drugs, 2) number of doses to take ≥ 4 times, and 3) regular use of benzodiazepines or insomnia. Subsequently, the PD rate was compared during a period of two years and 6 months between the pre-PBPM (n = 39) and post-PBPM (n = 62). The PD rate for elective valve replacement or valvuloplasty was 25% (35/142). The adjusted odds ratio for polypharmacy was 3.3 (95% confidence interval: 1.2-8.9, p = 0.016), suggesting that preoperative risk assessment may be essential for patients with polypharmacy. The PD rate significantly decreased to 13% (8/62) in the post-PBPM group compared with 33% (13/39) in the pre-PBPM group (p = 0.014). There was a significant decrease in benzodiazepines use in post-PBPM compared with pre-PBPM (p = 0.026); however, the rate of ramelteon and orexin receptor antagonists use increased by PBPM introduction (p < 0.001). Although the present PBPM still requires further modification, it is simple and potentially useful for pharmacists to assess the risk of patients undergoing any elective cardiovascular surgery.

Radiation dosimetry and pharmacokinetics of the tau PET tracer florzolotau (18F) in healthy Japanese subjects.

OBJECTIVE: Abnormal aggregation of tau in the brain is a major contributing factor in various neurodegenerative diseases. Florzolotau (18F) (florzolotau, APN-1607, PM-PBB3) has been shown to be a probe for tau fibrils in an animal model and patients with Alzheimer's disease and those with non-Alzheimer's disease tauopathies. The objective of this study is to evaluate the safety, pharmacokinetics, and radiation dose following a single intravenous administration of florzolotau in healthy Japanese subjects. METHODS: Three healthy male Japanese subjects aged between 20 and 64 were enrolled in this study. Subjects were determined to be eligible based on the screening assessments at the study site. Subjects received a single intravenous dose of 195.0 ± 0.5 MBq of florzolotau and underwent the whole-body PET scan 10 times in total to calculate absorbed doses to major organs/tissues and effective dose. Radioactivities in whole blood and urine were also measured for pharmacokinetic evaluation. Absorbed doses to major organs/tissues and effective dose were estimated using the medical internal radiation dose (MIRD) method. Vital signs, electrocardiography (ECG), and blood tests were done for safety evaluation. RESULTS: The intravenous injection of florzolotau was well tolerated. There were no adverse events or clinically detectable pharmacologic effects related to the tracer in any subjects. No significant changes in vital signs and ECG were observed. The highest mean initial uptake at 15 min after injection was in the liver (29.0 ± 4.0%ID), intestine (4.69 ± 1.65%ID), and brain (2.13 ± 0.18%ID). The highest absorbed dose was 508 µGy/MBq of the gallbladder wall, followed by the liver of 79.4 µGy/MBq, the pancreas of 42.5 µGy/MBq, and the upper large intestine of 34.2 µGy/MBq. The effective dose was calculated as 19.7 µSv/MBq according to the tissue weighting factor reported by ICRP-103. CONCLUSION: Florzolotau intravenous injection was well tolerated in healthy male Japanese subjects. The effective dose was determined as 3.61 mSv when 185 MBq florzolotau was given.

Risk factors and prognosis of humeral head inferior subluxation in proximal humeral fractures after osteosynthesis.

BACKGROUND: Humeral head inferior subluxation often occurs immediately after osteosynthesis for proximal humeral fracture; however, the underlying cause remains largely unknown. In addition, the prognosis of postoperative inferior subluxation has not been fully investigated. This study aimed to clarify the predictive factors that affected the onset of postoperative inferior subluxation using multivariate analysis and examine the postoperative course of inferior subluxation and its influence on postoperative outcomes. METHODS: We retrospectively reviewed 212 patients who underwent osteosynthesis for Neer 2- or 3-part proximal humeral fractures. In the multivariate analysis, the dependent variable was set as the inferior subluxation observed 1 week after the surgery. The explanatory variables included age, sex, affected side, body mass index, smoking, local osteoporosis, preoperative axillary nerve injury, time from injury to surgery, fracture dislocation, fracture pattern, preoperative inferior subluxation, surgical procedure, surgical approaches, blood loss, operative time, and postoperative drainage. Baseline variables, which were observed to be significant in the univariate analysis, were included in multivariate models. Furthermore, based on the presence of inferior subluxation at 1 week after the surgery, we divided the patients into two groups: with inferior subluxation (+IS group) and without inferior subluxation (-IS group). We compared the postoperative outcomes (incidence of postoperative complications and range of motion) between these two groups. RESULTS: Of 212 patients, 64 (30.7%) experienced inferior subluxation at 1 week after the surgery. On multivariate analyses, preoperative inferior subluxation (odds ratio = 4.69; 95% confidence interval = 2.45-9.76; P < .001) and longer operative time (odds ratio = 1.01; 95% confidence interval = 1.00-1.02; P = .049) were the risk factors for postoperative inferior subluxation. In the +IS group, inferior subluxation resolved at 1 year after the surgery in 89.5% of patients. There was no significant difference in the postoperative outcome between the +IS and -IS groups. However, four of six patients with persistent inferior subluxation, more than 6 months after the surgery, experienced complications, such as varus angulation of the humeral head or screw joint perforation. CONCLUSIONS: This study provides new information on the risk factors for and prognosis of postosteosynthesis inferior subluxation in patients with proximal humeral fracture. Longer operative time and presence of preoperative inferior subluxation was associated with an increased risk of postoperative inferior subluxation, although it was temporary in most cases, and had no significant influence on the postoperative outcomes. However, in patients with persistent inferior subluxation of more than 6 months duration, inferior subluxation may be related to postoperative complications.

Physiologically decreased F-18 fluorodeoxyglucose uptake in the lower vertebrae associated with daily drinking habit in Japanese men with alcohol flushing reaction.

Alcohol flushing reaction (AFR) is known as one of the risks for esophageal squamous cell cancer, and scientists have been elucidating this issue. However, little attention has been given to relevant imaging features. This study aims to investigate whether physiological 18F-fluorodeoxyglucose (FDG) uptake patterns in vertebrae are associated with drinking habits or AFR. Japanese male patients who underwent FDG positron emission computed tomography for evaluation of their known or suspected malignancies or inflammatory diseases were asked about their drinking habits and AFR. Altogether, 192 patients, 139 every-day drinkers and 53 non-drinkers were evaluated. Comparing the FDG uptake between that in the thoracic region and that in the lumbar region, vertebral uptake was visually classified into four patterns: Ld, dominant in lumbar region; TL, almost equal in both regions; BL, slightly higher in thoracic region (borderline pattern); Td, dominant in thoracic region. The uptake patterns were evaluated according to drinking habit (every-day drinker or non-drinker), AFR (flusher or non-flusher), and the combination of these two factors (habit/reaction: every-day drinker/flusher, every-day drinker/non-flusher, non-drinker/flusher, or non-drinker/non-flusher). There were 95 flushers (51 every-day drinkers and 44 non-drinkers) and 97 non-flushers (88 every-day drinkers and 9 non-drinkers). Ld, TL, BL, and Td patterns were observed in 0, 109 (56.8%), 31 (16.1%), and 52 (27.1%) patients, respectively. Td and BL patterns were more frequently observed in every-day drinkers compared with non-drinkers (p = 0.0467). Though the uptake patterns did not differ between flushers and non-flushers (p = 0.116), the Td pattern was more frequently observed in every-day drinkers/flushers (51%) compared with every-day drinkers/non-flushers (20.5%), non-drinkers/flushers (13.6%), and non-drinkers/non-flushers (22.2%) (p = 0.0014). The Td pattern was observed in patients with various diseases, with higher frequency in esophageal cancer, head and neck cancer, and lung cancer compared with other diseases. In conclusion, drinking habits and AFR were related to the vertebral uptake pattern with decreased uptake in the lumbar region in Japanese male patients.

Treatment of distal clavicle fractures using a Scorpion plate and influence of timing on surgical outcomes: a retrospective cohort study of 105 cases.

BACKGROUND: Plate fixation is an established method for treating unstable distal clavicle fractures. However, the appropriate timing of surgery for acute distal clavicle fractures remains unclear. The present study aimed to evaluate the clinical outcomes of osteosynthesis using a Scorpion plate and to assess the influence of surgery timing on the surgical outcomes for acute unstable distal clavicle fractures. METHODS: We retrospectively reviewed 105 patients who underwent fixation for acute unstable distal clavicle fractures (Neer type II and V) using the Scorpion plate between 2008 and 2018. Patients were divided into early (45 patients) and delayed (60 patients) treatment groups based on the timing of the surgical intervention (within or after 7 days). The outcomes were postoperative complications (nonunion, peri-implant fracture, plate loosening, plate-related pain, and stiffness). We evaluated the outcomes from X-ray radiographs and clinical notes. RESULTS: Among the 105 patients, nonunion, plate loosening, plate-related pain, and stiffness were observed in six patients (5.7%), four patients (3.8%), seven patients (6.7%), and one patient (1.0%), respectively. The nonunion rate was significantly higher in the delayed treatment group than that in the early treatment group (P = 0.036). Although the difference was not significant, plate loosening and stiffness were only observed in the delayed treatment group. CONCLUSION: Our results demonstrated that osteosynthesis using Scorpion plates achieved satisfactory surgical outcomes for unstable distal clavicle fractures. In addition, this study suggested that performing surgery within 6 days after injury is recommended to reduce postoperative complications.

Predominance and homogeneity patterns of physiological FDG accumulation in thoracic and lumbar vertebrae: suspected mechanism of "bone pseudometastasis" on FDG-PET in Japanese patients with esophageal cancer.

OBJECTIVE: False-positive bone lesions (bone pseudometastases) have been often reported in patients with esophageal cancer (EsoC). This study aimed to evaluate the vertebral 2-deoxy-2-[18F] fluoro-D-glucose (FDG) accumulation pattern in patients with newly diagnosed esophageal cancers and other malignancies (OtherT) to elucidate the possible mechanism that causes bone pseudometastasis. METHODS: FDG positron emission tomography/computed tomography performed for 90 patients with EsoC, and 112 patients with OtherT was retrospectively evaluated. The uptake pattern in the thoracic (Th) and lumbar (L) vertebrae was visually assessed regarding predominance (TL, Th ≒ L; Td, Th > L; Ld, L > Th), main intensity compared with the uptake in the blood pool (BP) (Grade 1 < BP, Grade 2 ≒ BP, or Grade 3 > BP), and homogeneity (homogeneous, heterogeneous, marginal, or spotty). The patterns between EsoC and OtherT and between Th and L were compared. RESULTS: TL, Td, and Ld patterns were observed in 51.1%, 48.9%, and 0% in EsoC and 79.7%, 20.3%, and 0% in OtherT. Though Grade 2 was most frequently observed in both groups, the ratio of Grade 3 in Th and Grade 1 in L was significantly higher in EsoC than in OtherT. Heterogeneous and spotty patterns were more frequently observed in L and in EsoC, and these were strongly associated with Td pattern. CONCLUSION: Td pattern was frequently seen, especially in EsoC, and was strongly associated with a heterogeneous or marginal pattern in the L. Heterogeneous marrow distribution with declined lumbar uptake is suspected as the mechanism of bone pseudometastasis.

Diffusely Decreased Liver Uptake on FDG PET and Cancer-Associated Cachexia With Reduced Survival.

OBJECTIVES: We investigated clinical characteristics of patients with extremely increased or decreased physiologic F-FDG uptake of the liver and their prognosis. METHODS: One thousand four hundred eighty-seven PET/CT scans of patients with known or suspected malignancy were retrospectively analyzed. A spherical volume of interest (3 cm in diameter) was set on the right lobe of the liver to calculate the SUVmean. Scans with extremely high (SUVmean >97.5th percentile) and low (SUVmean <2.5th percentile) FDG uptake in the liver were evaluated. Physical and laboratory data among a control group (n = 30), the extremely high liver uptake group (HG, n = 36), and the extremely low liver uptake group (LG, n = 36) were compared. Overall survival (OS) of the 3 groups was also compared. RESULTS: Body weight and body mass index in the HG (SUVmean ≥3.04) were significantly higher than those in the control group. The LG cases (SUVmean ≤1.78) had anemia, impaired liver function, and systemic inflammation. They were also in a poor nutritional state. The characteristics of LG cases had many things in common with those of cachectic patients. Indeed, 36.1% of LG cases met the diagnostic criteria for cachexia. Moreover, in LG cases with viable and/or recurrent malignant lesions on FDG PET, the proportion of cachexia increased by 52.6%. The OS of LG cases (median, 33 months) was significantly worse than that of controls and HG cases. CONCLUSIONS: Our data indicate that cancer patients with extremely decreased liver FDG uptake were likely to have cancer cachexia and a lower OS.

Bone Pseudometastasis on 18F-FDG PET in Japanese Patients With Esophageal Cancer.

PURPOSE OF THE REPORT: False-positive bone lesions mimicking bone metastases (bone pseudometastasis) on F-FDG PET/CT have often been reported in patients with esophageal cancer. We aimed to evaluate the prevalence and features of these lesions in Japanese patients with esophageal cancer. METHODS: In this retrospective study, we analyzed 83 FDG PET/CT studies for initial staging of esophageal cancer, and extracted patients with 1 or more localized high uptake sites with no subsequent progression, which were therefore judged to be bone pseudometastasis. The FDG PET/CT imaging features of the bone pseudometastasis were evaluated, and other available imaging and clinical features reviewed. RESULTS: Of the 83 patients, 7 had bone pseudometastasis. All 7 were males diagnosed with squamous cell cancer, of which 5 had T1a tumors. Bone pseudometastasis showed normal or ill-defined hyperdense (nonosteolytic) sites compared with the surrounding area on the CT. Additionally, accumulation in the upper vertebral levels of each case was contiguously high compared with the lumbar spines (we named this finding "contiguous accumulation"). On MRI, these findings were visualized as low signals on T1-weighted imaging (T1WI) and T2WI images but were unclear on fat-suppressed T2WI images. CONCLUSIONS: Among all PET/CT performed for staging of esophageal cancer, 8.3% demonstrated bone pseudometastasis characterized by heterogeneous distribution with severe fatty degeneration of bone marrow accompanied by contiguous accumulation. Caution is required during diagnoses of bone lesions in esophageal cancer patients in Japan to prevent inappropriate therapeutic choices.

Differential Diagnosis between Low-Grade and High-Grade Astrocytoma Using System A Amino Acid Transport PET Imaging with C-11-MeAIB: A Comparison Study with C-11-Methionine PET Imaging.

Introductions: [N-methyl-C-11]α-Methylaminoisobutyric acid (MeAIB) is an artificial amino acid radiotracer used for PET study, which is metabolically stable in vivo. In addition, MeAIB is transported by system A neutral amino acid transport, which is observed ubiquitously in all types of mammalian cells. It has already been shown that MeAIB-PET is useful for malignant lymphoma, head and neck cancers, and lung tumors. However, there have been no reports evaluating the usefulness of MeAIB-PET in the diagnosis of brain tumors. The purpose of this study is to investigate the efficacy of system A amino acid transport PET imaging, MeAIB-PET, in clinical brain tumor diagnosis compared to [S-methyl-C-11]-L-methionine (MET)-PET. Methods: Thirty-one consecutive patients (male: 16, female: 15), who were suspected of having brain tumors, received both MeAIB-PET and MET-PET within a 2-week interval. All patients were classified into two groups: Group A as a benign group, which included patients who were diagnosed as low-grade astrocytoma, grade II or less, or other low-grade astrocytoma (n=12) and Group B as a malignant group, which included patients who were diagnosed as anaplastic astrocytoma, glioblastoma multiforme (GBM), or recurrent GBM despite prior surgery or chemoradiotherapy (n=19). PET imaging was performed 20 min after the IV injection of MeAIB and MET, respectively. Semiquantitative analyses of MeAIB and MET uptake using SUVmax and tumor-to-contralateral normal brain tissue (T/N) ratio were evaluated to compare these PET images. ROC analyses for the diagnostic accuracy of MeAIB-PET and MET-PET were also calculated. Results: In MeAIB-PET imaging, the SUVmax was 1.20 ± 1.29 for the benign group and 2.94 ± 1.22 for the malignant group (p < 0.005), and the T/N ratio was 3.77 ± 2.39 for the benign group and 16.83 ± 2.39 for the malignant group (p < 0.001). In MET-PET, the SUVmax was 3.01 ± 0.94 for the benign group and 4.72 ± 1.61 for the malignant group (p < 0.005), and the T/N ratio was 2.64 ± 1.40 for the benign group and 3.21 ± 1.14 for the malignant group (n.s.). For the analysis using the T/N ratio, there was a significant difference between the benign and malignant groups with MeAIB-PET with p < 0.001. The result of ROC analysis using the T/N ratio indicated a better diagnosis accuracy for MeAIB-PET for brain tumors than MET-PET (p < 0.01). Conclusions: MeAIB, a system A amino acid transport-specific radiolabeled agents, could provide better assessments for detecting malignant type brain tumors. In a differential diagnosis between low-grade and high-grade astrocytoma, MeAIB-PET is a useful diagnostic imaging tool, especially in evaluations using the T/N ratio. Clinical trial registration: This trial was registered with UMIN000032498.

18F-FPYBF-2, a new F-18 labelled amyloid imaging PET tracer: biodistribution and radiation dosimetry assessment of first-in-man 18F-FPYBF-2 PET imaging.

OBJECTIVE: Recently, a benzofuran derivative for the imaging of ß-amyloid plaques, 5-(5-(2-(2-(2-18F-fluoroethoxy)ethoxy)ethoxy)benzofuran-2-yl)- N-methylpyridin-2-amine (18F-FPYBF-2) has been validated as a tracer for amyloid imaging and it was found that 18F-FPYBF-2 PET/CT is a useful and reliable diagnostic tool for the evaluation of AD (Higashi et al. Ann Nucl Med, https://doi.org/10.1007/s12149-018-1236-1 , 2018). The aim of this study was to assess the biodistribution and radiation dosimetry of diagnostic dosages of 18F-FPYBF-2 in normal healthy volunteers as a first-in-man study. METHODS: Four normal healthy volunteers (male: 3, female: 1; mean age: 40 ± 17; age range 25-56) were included and underwent 18F-FPYBF-2 PET/CT study for the evaluation of radiation exposure and pharmacokinetics. A 10-min dynamic PET/CT scan of the body (chest and abdomen) was performed at 0-10 min and a 15-min whole-body static scan was performed six times after the injection of 18F-FPYBF-2. After reconstructing PET and CT image data, individual organ time-activity curves were estimated by fitting volume of interest data from the dynamic scan and whole-body scans. The OLINDA/EXM version 2.0 software was used to determine the whole-body effective doses. RESULTS: Dynamic PET imaging demonstrated that the hepatobiliary and renal systems were the principal pathways of clearance of 18F-FPYBF-2. High uptake in the liver and the gall bladder, the stomach, and the kidneys were demonstrated, followed by the intestines and the urinary bladder. The ED for the adult dosimetric model was estimated to be 8.48 ± 1.25 µSv/MBq. The higher absorbed doses were estimated for the liver (28.98 ± 12.49 and 36.21 ± 15.64 µGy/MBq), the brain (20.93 ± 4.56 and 23.05 ± 5.03µ Gy/MBq), the osteogenic cells (9.67 ± 1.67 and 10.29 ± 1.70 µGy/MBq), the small intestines (9.12 ± 2.61 and 11.12 ± 3.15 µGy/MBq), and the kidneys (7.81 ± 2.62 and 8.71 ± 2.90 µGy/MBq) for male and female, respectively. CONCLUSIONS: The ED for the adult dosimetric model was similar to those of other agents used for amyloid PET imaging. The diagnostic dosage of 185-370 MBq of 18F-FPYBF-2 was considered to be acceptable for administration in patients as a diagnostic tool for the evaluation of AD.

Usefulness of three-dimensional magnetic resonance cholangiopancreatography with partial maximum intensity projection for diagnosing autoimmune pancreatitis.

PURPOSE: To compare three-dimensional magnetic resonance cholangiopancreatography (MRCP) with/without partial maximum intensity projection (MIP) and endoscopic retrograde cholangiopancreatography (ERCP) in patients with autoimmune pancreatitis (AIP). MATERIALS AND METHODS: Three-dimensional MRCP and ERCP images were retrospectively analyzed in 24 patients with AIP. We evaluated the narrowing length of the main pancreatic duct (NR-MPD), multiple skipped MPD narrowing (SK-MPD), and side branches arising from the narrowed portion of the MPD (SB-MPD) using four MRCP datasets: 5 original images (MIP5), 10 original images (MIP10), all original images (full-MIP), and a combination of these three datasets (a-MIP). The images were scored using a 3- or 5-point scale. The scores of the four MRCP datasets were statistically analyzed, and the positive rate of each finding was compared between MRCP and ERCP. RESULTS: The median scores for SB-MPD on MIP5 and a-MIP were significantly higher than those on MIP10 and full-MIP. In other words, partial MIP is superior to full-MIP for visualization of detailed structures. The positive rate for SB-MPD on full-MIP was significantly lower than that on ERCP, whereas the positive rate on MIP5, MIP10, and a-MIP was not significantly different from that on ERCP. Moreover, the positive rate for NR-MPD and SK-MPD on the MRCP images was significantly higher than that on the ERCP images. CONCLUSION: Partial MIP is useful for evaluating the MPD and is comparable with ERCP for diagnosing AIP.

Tumor-induced Osteomalacia Caused by a Parotid Tumor.

A 77-year-old man was suspected of having tumor-induced osteomalacia (TIO) because of hypophosphatemia (1.9 mg/dL) and elevated serum fibroblast growth factor 23 (FGF23) level (186.9 pg/mL). We detected a tumor in his left parotid gland, and the FGF23 level in the left external jugular vein indicated that the tumor overproduced FGF23. After the removal of the tumor, the serum FGF23 level rapidly decreased, and the serum phosphate normalized. This is the first case of TIO caused by a tumor in a parotid gland. This case indicates that the responsible tumors for TIO can be quite diverse.

Unusual Presentation of Popliteal Cyst on Magnetic Resonance Imaging.

Popliteal cyst commonly presents as an ellipsoid mass with uniform low signal intensity on T1-weighted magnetic resonance images and high signal intensity on T2-weighted images. Here, we describe a popliteal cyst with unusual appearance on magnetic resonance imaging, including heterogeneous intermediate signal intensity on T2-weighted images. Arthroscopic cyst decompression revealed that the cyst was filled with necrotic synovial villi, indicative of rheumatoid arthritis. Arthroscopic enlargement of unidirectional valvular slits with synovectomy was useful for the final diagnosis and treatment.

Giant Intraosseous Cyst in an Osteoarthritic Knee.

This article describes osteoarthritis of the knee and a giant intraosseous cyst of the medial femoral condyle in an 83-year-old man that was treated successfully with total knee arthroplasty and autologous bone grafts. The patient presented to the authors' hospital with a 2-year history of right knee pain. A plain radiograph of the right knee revealed grade 3 medial compartment osteoarthritis with an oval area of radiolucency in the medial femoral condyle. The area of radiolucency seen on the radiograph was larger than that on the radiograph obtained 2 years earlier, with no progression of osteoarthritis. Computed tomography showed a well-defined giant intraosseous cyst adjacent to the medial femoral cortex measuring 3.5×3.5×1.6 cm. A medial femoral cortical defect and a small bone break on the articular surface of the medial femoral condyle, both of which allowed communication between the cyst and the joint, were also detected, along with gases in the cyst. Total knee arthroplasty with bone grafts was performed. Resection of the distal femur revealed that the fatty synovia intruded into the cyst through the medial cortical defect. Two years after the surgery, the grafted bone was well incorporated, without loosening of the prosthesis. Two theories, the synovial intrusion theory and the bone contusion theory, have been proposed for the etiology of cyst formation in an osteoarthritic knee. The current case strongly supports the synovial intrusion theory as the mechanism underlying the development of an intraosseous giant cyst in the osteoarthritic knee. [Orthopedics. 2016; 39(6):e1193-e1196.].

(11)C-methylaminoisobutyric acid (MeAIB) PET for evaluation of prostate cancer: compared with (18)F-fluorodeoxyglucose PET.

OBJECTIVE: α-N-methyl-(11)C-methylaminoisobutyric acid ((11)C-MeAIB) is a selective substrate of system A amino acid transport, and known to accumulate in malignant lesions. The aim of this study was to evaluate the utility of MeAIB PET for the assessment of prostate cancer, compared with FDG PET. METHODS: Thirty-four men (age range 57-77 years) with prostate cancer were prospectively enrolled, and underwent MeAIB PET and FDG PET between January 2011 and January 2013. MeAIB PET and FDG PET were performed at 20 and 50 min post-injection, respectively. SUVmax of the prostate was calculated, and visual analysis was conducted for MeAIB and FDG PET studies. MRI images were visually evaluated if available. All patients received total prostatectomy subsequently, and imaging findings were compared with pathological results, including T stage, Gleason score, and tumor size. The patient-based and lesion-based sensitivity and specificity were calculated according to pathological significant cancer. RESULTS: Mean value of SUVmax of (11)C-MeAIB PET and (18)F-FDG PET in prostate cancer were 3.18 (±1.90, range; 1.55-9.57) and 3.88 (±2.85, range; 2.04-14.47). MeAIB PET and FDG PET were positive by visual analysis in 47.1 % (16/34) and 44.1 % (15/34) of the patients. MRI was positive in 51.5 % (17/33). Pathological stage and Gleason score were as follows: Stage 2 (n = 23), 3 (n = 8), and 4 (n = 3); Gleason score 6 (n = 13), 7 (n = 16), 8 (n = 3), and 9 (n = 2). The sensitivities tended to be higher according to higher pathological T stage or Gleason sum score for both MeAIB and FDG PET studies. Visual analysis of both MeAIB PET and FDG PET had significant correlation with extraprostatic extension (p < 0.05). MeAIB PET and FDG PET had complementary results by visual analysis in the assessment of prostate cancer. The patient-based sensitivity of MeAIB PET, FDG PET, and MRI were 51.6, 48.4, and 56.7 %, respectively. The patient-based specificity of these modalities was 100 % for each modality. CONCLUSIONS: MeAIB PET has better diagnostic results than FDG PET for the assessment of significant prostate cancer, and these PET studies showed complementary results. MRI has even better diagnostic results than (11)C-MeAIB PET. MeAIB accumulates in prostate cancer, which indicates that the system A amino acid transport pathway is activated in prostate cancer.

Elevated erythrocyte sedimentation rate and high-sensitivity C-reactive protein in osteoarthritis of the knee: relationship with clinical findings and radiographic severity.

PURPOSE: We assessed erythrocyte sedimentation rate and high-sensitivity C-reactive protein concentration in knee osteoarthritis and non-knee osteoarthritis. In addition, we investigated potential relationship between the levels of erythrocyte sedimentation rate and high-sensitivity C-reactive protein with clinical findings and radiographic severity. METHODS: We compared erythrocyte sedimentation rate and high-sensitivity C-reactive protein concentration between 104 patients with knee osteoarthritis (knee osteoarthritis group; 25 males, 79 females; mean age, 73 y) and 50 patients without knee osteoarthritis (non-knee osteoarthritis group; 16 males, 34 females; mean age, 64 y) excluding any patients with comorbid joint osteoarthritis, rheumatoid arthritis, malignant tumours or inflammatory diseases. In the knee osteoarthritis group, we assessed whether erythrocyte sedimentation rate and high-sensitivity C-reactive protein concentration differed in clinical features and Kellgren-Lawrence (KL) grades. RESULTS: Erythrocyte sedimentation rate and high-sensitivity C-reactive protein were significantly higher in the knee osteoarthritis group than in the non-knee osteoarthritis group (P = 0.0013 and 0.00010, respectively). In the knee osteoarthritis group, erythrocyte sedimentation rate was significantly elevated in patients with tenderness and patellar ballottement (P = 0.032 and 0.038, respectively), and high-sensitivity C-reactive protein concentration was significantly elevated in patients with tenderness, swelling and patellar ballottement (P = 0.0042, 0.00030 and 0.019, respectively). Erythrocyte sedimentation rate in KL-I was lower than erythrocyte sedimentation rate in KL-III and -IV (P = 0.012 and 0.037, respectively). Erythrocyte sedimentation rate in KL-II did not significantly differ from erythrocyte sedimentation rate in the other groups. High-sensitivity C-reactive protein concentration was lower in grade I than in KL-II, -III and -IV (P = 0.044, 0.0085 and 0.049, respectively). CONCLUSIONS: Erythrocyte sedimentation rate and high-sensitivity C-reactive protein concentration were higher in patients with knee osteoarthritis and were related to clinical features. In knee osteoarthritis, high-sensitivity C-reactive protein concentration may increase in early-stage KL-II.

Arthroscopic approach to the posterior compartment of the knee using a posterior transseptal portal.

Arthroscopic surgery of the posterior compartment of the knee is difficult when only two anterior portals are used for access because of the inaccessibility of the back of the knee. Since its introduction, the posterior transseptal portal has been widely employed to access lesions in the posterior compartment. However, special care should be taken to avoid neurovascular injuries around the posteromedial, posterolateral, and transseptal portals. Most importantly, popliteal vessel injury should be avoided when creating and using the transseptal portal during surgery. Purpose of the present study is to describe how to avoid the neurovascular injuries during establishing the posterior three portals and to introduce our safer technique to create the transseptal portal. To date, we have performed arthroscopic surgeries via the transseptal portal in the posterior compartments of 161 knees and have not encountered nerve or vascular injury. In our procedure, the posterior septum is perforated with a 1.5-3.0-mm Kirschner wire that is protected by a sheath inserted from the posterolateral portal and monitored from the posteromedial portal to avoid popliteal vessel injury.

Treatment of popliteal cysts via arthroscopic enlargement of unidirectional valvular slits.

OBJECTIVE: The aim of the present study was to investigate the efficacy of arthroscopic enlargement of unidirectional valvular slits for the treatment of popliteal cysts and to evaluate potential factors affecting the outcomes of our arthroscopic procedure. METHODS: Twenty-nine patients aged 43-77 years with popliteal cysts were treated with arthroscopic cyst decompression. Surgery was performed via two posterior portals after creating a transseptal portal. Rauschning and Lindgren clinical score, magnetic resonance images, and osteoarthritic grade were evaluated pre- and postoperatively, and cartilage degeneration class was confirmed via arthroscopy. The mean follow-up period was 22.9 ± 14.6 months (range, 9-60 months). RESULTS: Twelve cysts disappeared completely (group D), while 16 reduced and one enlarged (group R) in size by the final follow-up. Twenty-two (75.9%) of 29 popliteal cysts diminished to a volume that was less than 10% of the preoperative volume. Clinical scores improved in 93.1% of the patients, and more patients (68.8%) in group R had positive joint effusion at the final follow-up compared with group D (17.7%; p < 0.01). CONCLUSIONS: Arthroscopic cyst decompression was effective in the treatment of symptomatic popliteal cysts. Intra-articular pathologies associated with joint effusion should be corrected simultaneously.