Automated detection and classification of the rotator cuff tear on plain shoulder radiograph using deep learning

BACKGROUND

The diagnosis of rotator cuff tears (RCTs) using radiographs alone is clinically challenging; thus, the utility of deep learning algorithms based on convolutional neural networks has been remarkable in the field of medical imaging recognition. We aimed to evaluate the diagnostic performance of artificial intelligence (a deep learning algorithm; a convolutional neural network) to detect and classify RCTs using shoulder radiographs, and compare its diagnostic performance with that of orthopedic surgeons.

METHODS

A total of 1169 plain shoulder anteroposterior radiographs (1 image per shoulder) were included in the total dataset and divided into four groups: intact, small, medium, and large to massive tear groups. The sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and area under the receiver operating curve were measured for the detection of RCTs through binary classification. The average accuracy, recall, precision, and F1-score were divided into four groups by cuff tear size for multiclass classification.

RESULTS

The convolutional neural network demonstrated a high performance, with 92% sensitivity, 69% specificity, 86% accuracy, and an area under the receiver operating curve of 0.88 for the detection of RCTs. The average accuracy, recall, precision, and F1-score of the convolutional neural network for classification were 60%, 0.42, 0.49, and 0.45, respectively. The accuracy of the convolutional neural network for the detection and classification of RCTs was significantly better than that of orthopedic surgeons.

CONCLUSION

The convolutional neural network demonstrated the diagnostic ability to detect and classify RCTs using plain shoulder radiographs, and the diagnostic performance exhibited equal to superior accuracy when compared with those of shoulder experts.

Efficacy of radial shock wave therapy on rat models of adjuvant arthritis

BACKGROUND

Extracorporeal shock wave therapy (ESWT) is an effective treatment for musculoskeletal pain, tendinopathy, and fasciitis with an anti-inflammatory effect. ESWT can be categorized into two groups: radial pressure wave (RPW) and focused shock wave (FSW). Although there have been several studies on the inflammation and pain-improvement mechanisms of FSW, there are few studies on the pain-improvement mechanisms of RPW. This study aimed to elucidate the efficacy of RPW in a rat model of adjuvant arthritis.

METHODS

Ninety-six rats were randomly categorized into three groups: RPW, control, and sham as follows: (I) RPW group, which received RPW application after complete Freund's adjuvant (CFA) injection; (II) Control group, which received only CFA injection; and (III) Sham group, which received only saline injection. All rats were evaluated at 0, 4, 7, 14, 28, and 56 days post-RPW application based on foot circumference, von Frey test, and immunohistochemistry of nerve fibers for calcitonin gene-related peptide (CGRP) and protein gene product (PGP) 9.5 in plantar skins.

RESULTS

There were no significant differences in foot circumference between the RPW and control groups at any time point. The RPW group showed significant improvements in the von Frey test results on days 7 and 14. The total CGRP-immunoreactive (ir) and PGP9.5-ir nerve fiber lengths in the RPW group decreased on day 0; however, both were increased in the control group. The CGRP-ir and PGP9.5-ir nerve fibers in the RPW group were significantly shorter than those in the control group until day 14 after RPW.

CONCLUSIONS

RPW improved the mechanical hypersensitivity between days 7 and 14 after application. Like FSW, RPW also induced the degeneration of sensory nerve fibers in the skin in the early period after irradiation, and reinnervation occurred between 14 and 28 days. Thus, our results demonstrate one of the pain relief mechanisms after RPW application.

Evaluation of articular changes using a rat mono-iodoacetate-induced shoulder arthritis model by histology and radiology

The rat mono-iodoacetate (MIA) arthritis model has been used in studies on the hip, knee, and ankle joints. Few studies have explored its utility in shoulder arthritis research, and none have evaluated the effects of time and different MIA doses on arthritis progression. Therefore, we developed a rat MIA shoulder arthritis model to evaluate articular changes through radiological and histological analyses. Sprague-Dawley rats (n = 108) were equally divided into groups that were intra-articularly injected with 0.5 mg of MIA (in 50 µL of purified water), 2.0 mg of MIA (in 50 µL of purified water), or purified water (50 µL; sham group). Throughout the study period, 18 rats (six per group) were evaluated by computed tomography and assessed using the Larsen's classification system; 90 rats were further evaluated histologically using the Osteoarthritis Research Society International scoring system. Computed tomography revealed that the groups injected with MIA developed arthritis and osteophytes 14 days after injection, which progressed temporally. The Larsen's grades worsened over time; at all time points, the scores were higher in the group injected with 2.0 mg of MIA than in the group injected with 0.5 mg of MIA. Furthermore, concurrent with the worsening Larsen's grades, the Osteoarthritis Research Society International scores also significantly increased over time; at all time points, they were higher in the group injected with 2.0 mg of MIA than in the group injected with 0.5 mg of MIA. Our rat MIA shoulder arthritis model revealed radiologically and histologically confirmed temporal and MIA dose-dependent arthritic changes.

Biomechanical Comparison of Stability and Strength After Ulnar Collateral Ligament Reconstruction With Suture Anchor Fixation Versus Bone Tunnels

Background

Ulnar collateral ligament (UCL) injuries occur frequently in baseball players, and UCL reconstruction is performed when nonoperative treatment fails.

Purpose

To compare a novel all-suture anchor method of UCL reconstruction with a method using bone tunnels (Ito method) by investigating the displacement against valgus torque and the failure strength.

Study Design

Controlled laboratory study.

Methods

Eight fresh-frozen cadaveric upper extremities (mean age, 82.0 years) were utilized in this study. To evaluate the displacement against valgus torque, the valgus stability test was performed for 4 anterior oblique ligament (AOL) conditions: intact AOL, resected AOL, reconstructed using the anchor method, and reconstructed using the Ito method. The load-to-failure test was performed to evaluate the failure strength of the anchor and Ito methods. Displacement against valgus load was compared between conditions using the repeated-measures 2-way analysis of variance with Bonferroni post hoc test, and failure strength between the anchor and Ito methods was compared using the unpaired t test.

Results

Displacements of the intact AOL and anchor method were significantly greater than those of the resected AOL at both 60° and 90° of flexion (intact AOL: P = .005 and P < .001, respectively; and anchor method: P = .024 and P < .001, respectively). The displacement of the Ito method at 90° of flexion was significantly greater than that of the resected AOL (P = .003), but no significant difference was observed at 60° of flexion (P = .109). There were no significant differences in displacement between the anchor and Ito methods at any flexion angle, nor was there a significant difference in failure torque between the anchor and Ito methods (16.3 ± 3.1 vs 17.6 ± 2.3 N·m, respectively; P = .537).

Conclusion

The displacement and failure strength against a valgus load after UCL reconstruction using a suture anchor on the ulnar side were equal to those using bone tunnels.

Clinical Relevance

UCL reconstruction using a suture anchor on the ulnar side is simpler and less invasive than using bone tunnels, with similar outcomes.

Postoperative complications of reverse total shoulder arthroplasty: a multicenter study in Japan

Background

Reverse total shoulder arthroplasty (RSA) has been approved since 2014 in Japan, and the number of RSA cases has been accumulating. However, only short-to medium-term outcomes have been reported, with a small number of case series, because of its short history in Japan. This study aimed to evaluate complications after RSA in hospitals affiliated with our institute, with comparison to those in other countries.

Methods

A multicenter retrospective study was performed at 6 hospitals. In total, 615 shoulders (mean age: 75.7 ± 6.2 years; mean follow-up: 45.2 ± 19.6 months) with at least 24 months of follow-up were included in this study. The active range of motion was assessed pre-and postoperatively. The 5-year survival rate was evaluated for reoperation for any reason in 137 shoulders with at least 5 years of follow-up using Kaplan-Meier analysis. Postoperative complications were evaluated, including dislocation; prosthesis failure; deep infection; periprosthetic, acromial, scapular spine, and clavicle fractures; neurological disorders; and reoperation. Furthermore, imaging assessments, including scapular notching, prosthesis aseptic loosening, and heterotopic ossification were evaluated on postoperative radiography at the final follow-up.

Results

All range of motion parameters were significantly improved postoperatively (P < .001). The 5-year survival rate was 93.4% (95% confidence interval: 87.8%-96.5%) for reoperation. Complications occurred in 256 shoulders (42.0%), with reoperation in 45 (7.3%), acromial fracture in 24 (3.9%), neurological disorders in 17 (2.8%), deep infection in 16 (2.6%), periprosthetic fracture in 11 (1.8%), dislocation in 9 (1.5%), prosthesis failure in 9 (1.5%), clavicle fracture in 4 (0.7%), and scapular spine fracture in 2 (0.3%). Regarding imaging assessments, scapular notching was observed in 145 shoulders (23.6%), heterotopic ossification in 80 (13.0%), and prosthesis loosening in 13 (2.1%).

Conclusion

This is the first large case series to investigate the complications after RSA in Japan, and the overall frequency of complications after RSA was similar to that in other countries.

The antimicrobial protein S100A7/psoriasin enhances the expression of keratinocyte differentiation markers and strengthens the skin's tight junction barrier

BACKGROUND

S100A7/psoriasin is a member of the S100 protein family and is encoded in the epidermal differentiation complex, which contains genes for markers of epidermal differentiation. S100A7/psoriasin is overexpressed in hyperproliferative skin diseases, where it is believed not only to exhibit antimicrobial functions, but also to induce immunomodulatory activities, including chemotaxis and cytokine/chemokine production.

OBJECTIVES

To evaluate the effect of S100A7/psoriasin on keratinocyte differentiation and regulation of the tight junction (TJ) barrier.

METHODS

Expression of differentiation markers and TJ proteins in human keratinocytes was determined by real-time polymerase chain reaction and Western blot. The changes in TJ barrier function were assessed by transepithelial electrical resistance and paracellular permeability assays. Glycogen synthase kinase-3 (GSK-3) and mitogen-activated protein kinase (MAPK) activation was analysed by Western blot, whereas β-catenin and E-cadherin activation was evaluated by Western blot and immunofluorescence.

RESULTS

S100A7/psoriasin enhanced the expression of several differentiation markers and selectively increased the expression of TJ proteins (e.g. claudins and occludin), which are known to strengthen the TJ barrier. Furthermore, S100A7/psoriasin increased β-catenin and E-cadherin accumulation at cell-cell contact, and enhanced transepithelial electrical resistance while reducing the paracellular permeability of keratinocyte layers. The data suggest that S100A7/psoriasin-mediated regulation of the TJ barrier was via both the GSK-3 and MAPK pathways, as evidenced by the inhibitory effects of inhibitors for GSK-3 and MAPKs.

CONCLUSIONS

Our finding that S100A7/psoriasin regulates differentiation and strengthens TJ barrier function provides novel evidence that, in addition to antimicrobial and immunoregulatory activities, S100A7/psoriasin is involved in skin innate immunity.

[Radiological assessment of the structural relationship between the trachea and the innominate artery in physically disabled and scoliotic children]

Studies were made on the physically disabled and scoliotic children who underwent tracheostomy. The purpose was to clarify factors that might lead to the tracheo-innominate artery fistula, by use of three-dimensional helical CT (3 DCT). In a case of right scoliosis, the tracheo-innominate artery fistula may be caused by the left-ward displacement of the trachea from the vertebra, having the innominate artery ride over the trachea and compressing it. In a case of the physically disabled and scoliotic children, there may be more compression on the trachea by the innominate artery along with the worsening scoliosis. Therefore, we consider it necessary to examine the structural relationship between the trachea, the vertebra, and the innominate artery periodically by 3 DCT.

Propiverine-induced Parkinsonism: a case report and a pharmacokinetic/pharmacodynamic study in mice

PURPOSE

We present a case report of propiverine-induced Parkinsonism. We previously reported the induction of catalepsy by amiodarone, aprindine and procaine, which possess a diethylaminomethyl moiety and demonstrated selective blockade of dopamine D2 receptors by these drugs in mice. We hypothesized that drugs possessing a diethylaminomethyl structure may generally induce Parkinsonism and/or catalepsy.

METHODS

Thus, we performed a study to examine whether oxybutynin, pentoxyverine and etafenone, as well as propiverine, induce catalepsy in mice.

RESULTS

The intensity of drug-induced catalepsy was in the order: haloperidol > etafenone > pentoxyverine > propiverine > oxybutynin. In vivo occupancy of dopamine D1, D2 and mACh receptors in the striatum was also examined. The in vitro binding affinities to the D1, D2 and mACh receptors in the striatum synaptic membrane were within the ranges of 2.4-140 microM, 380-4,200 nM, and 1.2-2,800 nM, respectively.

CONCLUSIONS

These results support the idea that any drug possessing a diethylaminomethyl moiety may contribute to the induction of catalepsy, possibly by occupying dopamine receptors.

Sudden death in chronic dialysis patients

METHODS

Causes of sudden death were investigated in 113 chronic dialysis patients who died during the 10-year period from July 1979 to January 1989; postmortem examination was performed on 93 of the cases (autopsy rate; 82.3%). Sudden death was regarded as death 24 h after the onset of acute illness in patients without any restriction in their daily activities. There were 35 sudden death cases out of the 93 autopsied chronic dialysis patients. We analysed the causes of sudden death for all chronic dialysis patients and for those who died suddenly.

RESULTS

The mean age of the 93 cases was 61.4 +/- 10.5 years (+/-SD). Stroke was the most frequent cause of death (24 cases, 25.8%) in the 93 autopsied cases. This was followed by cardiac disease in 18 (19.4%), infectious disease in 16 (17.2%), malignancy in 14 (15.1%), and dissecting aortic aneurysm in 5 (5.4%). The mean age of the 35 sudden death cases was 60.9 +/- 10.9 years. Of the 35 sudden death cases in chronic dialysis patients, dissecting aortic aneurysm was the most common cause of sudden death (5 cases, 14.3%), followed by cerebral haemorrhage in three (8.6%), acute subdural haematoma in three (8.6%), acute myocardial infarction in two (5.7%), cerebral infarction in two (5.7%), and subarachnoidal haemorrhage in one (2.9%).

CONCLUSIONS

Dissecting aortic aneurysm, leading frequently to stroke as a cause of sudden death in chronic dialysis patients, at least in Japan, should be carefully differentiated from other cardiac diseases in chronic dialysis patients, such as severe atherosclerosis.

Combined therapy with arbekacin and fosfomycin for methicillin-resistant Staphylococcus aureus infections

We examined the clinical efficacy of a combination of arbekacin and fosfomycin in the treatment of various methicillin-resistant Staphylococcus aureus (MRSA) infections. The combination of arbekacin plus fosfomycin displayed 65.4% (17/26) clinical efficacy and 65.4% (17/26) bacteriological efficacy. This combination thus appeared to be an effective regimen for the treatment of MRSA infections. However, its bacteriological efficacy against concomitant Pseudomonas aeruginosa strains was only 16.7% (1/6). In addition, in 4 episodes of superinfection involving P. aeruginosa strains developed during the combination therapy.

Primary hyperoxaluria type I due to a point mutation of T to C in the coding region of the serine:pyruvate aminotransferase gene

cDNA clones for serine:pyruvate aminotransferase (SPT, alternative name: alanine:glyoxylate aminotransferase) were obtained from a cDNA library constructed from the liver of a primary hyperoxaluria type I (PH1) case in which the SPT activity was approximately one-hundredth that in control liver. Six clones were isolated from 100,000 transformants and all of them contained an approximately 1.5 kbp insert which included the whole coding region for human SPT. Nucleotide sequence analysis revealed a point mutation of T to C at position 634 (relative to the 5'-end of the cDNA) encoding a Ser to Pro substitution at residue 205. The T to C conversion created a new SmaI site, which enabled us to demonstrate that the point mutation had occurred in the patient's SPT gene. SmaI digestion of genomic DNA may be useful for the diagnostic gene analysis of this type of PH1.

[Clinico-pathological studies on Is, Ip polyps and flat elevations in the large intestine]

We histologically compared 3 types of adenoma and cancer of the large intestine using 620 adenoma specimens (509 Is type lesions, 83 Ip type lesions, and 28 flat type lesions) and 113 specimens of early stage cancer (51 Is type lesions, 39 Ip type lesions, and 23 flat type lesions) obtained during the past 5-year period at our department. More than 90% of the Is and Ip type polyps were adenoma or carcinoma in adenoma while 25.5% of the flat elevations were m or sm carcinoma. Flat elevations even less than 10 mm in diameter were frequently carcinomas (26.3%) compared with the other types (both Is and Ip types, 6.7%), and all of those 10 mm or more in size were carcinomas. The distribution of the flat type early cancers in the large intestine was similar to that of advanced cancer with high percentages of carcinoma at each site compared with the other types. These results suggest that the carcinogenesis and progression of flat type early stage cancer differ from those of the other types.

[Prognosis of intra-arterial chemo-embolization in metastatic liver cancer]

We treated 63 patients (pts) suffering from metastatic liver cancer with intra-arterial infusion chemotherapy, and analysed 44 of their for survival since the first treatment with regard to the primary foci of cancer and the method of intra-arterial therapy. Via the superficial femoral artery, we performed superselective hepatic catheterization by Seldinger's method. Three types of intraarterial therapy were used: Gelfoam embolization with mitomycin-C (MMC) in 12 pts (GS-TAE), capillary chemo-embolization with MMC-Lipiodol emulsion in 28 pts (LP-TAI) and "one-shot" slow infusion of MMC or cisplatinum in 4 pts. Fifty-percent survival was 189 days in pts with metastases from colo-rectal cancer (n = 20), 109 days from gastric cancer (n = 9), 100 days from pancreatobiliary cancer (n = 5) and 240 days from breast cancer (n = 7). More than one-year survival was obtained in 13 out of the 40 pts (32.5%). Survival of 12 pts, treated with GS-TAE regimen, was not significantly superior to that of 28 pts with LP-TAI regimen. Hence, we conclude that LP-TAI is the treatment of choice in chemo-embolization for unresectable liver metastases, because it causes less damage to the hepatic arterial beds, and facilitates repeat intraarterial therapy in these pts.

[Preoperative chemoembolization of iopamiron-solved adriamycin and lipiodol on hepatocellular carcinoma--clinicopathological study of ten surgical cases]

Preoperative chemoembolization was performed in 10 patients with hepatocellular carcinoma. The therapeutic regimen included Adriamycin (ADM) solved in nonionic contrast media, Iopamiron and Lipiodol (LP). Two to four ml of the solution, containing 20-40 mg of ADM, was mixed with 5-10 ml of LP by "pumping" method. This emulsion was infused superselectively into the hepatic artery by the balloon-occluded method. The regimen contained no permanent embolic material (e.g., Gelfoam or Ivaron). Dense deposition of LP in the tumor was seen on the CT scan 3-4 weeks after TAI. Surgical specimens, resected 3-12 weeks after TAI, revealed total necrosis of the tumor in 4 cases, subtotal necrosis (more than 80% on the cut surface) in 3 cases, and partial necrosis (less than 80%) in 3 cases. Tumor invasion in the fibrous capsules was necrosed in 4/7 of the cases. Tumor thrombi in the portal vein were also necrosed in 2/4. Our new method is more effective than the previous ones of LP and ADM without Iopamiron, and is equally effective as the regimen using LP, anticancer drugs, and permanent embolic materials.

[A case of colonic carcinoma associated with intestinal tuberculosis, and an analysis of 26 cases reported in Japan]

A case of tuberculosis and adenocarcinoma co-existing in the ileocecal region in a 61-yr-old woman is described. The Japanese literature is reviewed and several points discussed regarding the epidemiological and morphological features in a colon carcinoma associated with tuberculosis. (1) Females predominate by a ratio of 17:9 in such cases. (2) The tumor has been found in the right side of the colon in 17 out of 26 cases. (3) The most characteristic histological finding is that of the cancer, which shows a well differentiated adenocarcinoma with a tendency to produce a mucin. These unique findings are consistent with those in our case. It is of interest that these unique findings may support the possibility that the cancer originated from a tuberculous lesion.

Gastric leiomyoblastoma: report of a case

The case of a 38-year-old man with an exogastric leiomyoblastoma is reported. CT and ultrasound examinations revealed a large mass in the left hypochondrium that had both solid and cystic components. These findings mimicked those of cystadenoma of the pancreas. Because of intraperitoneal hemorrhage in the preoperative course, emergency laparotomy was performed. A large tumor was found to arise from the greater curvature of the stomach. The diagnosis was confirmed histologically.

An experimental study on the origin of foam cells in glomerulonephritis

Masugi nephritis induced in cholesterol-fed rabbits is characterized by accumulation of foam cells in glomeruli which vary in number almost in parallel with the natural course of the disease. From electron microscopic appearances these foam cells are apparently derived from migrant blood monocytes and mesangial cells, but not from endothelial cells. Location of monocytic foam cells is extremely variable, though most often observed in the subendothelial space. In addition, monocytes undergo transformation into multinucleated giant cells including Touton type's. Lipid deposits filling the cytoplasm of foam cells seem to be in two forms, free cytoplasmic droplets and membrane-bounded structures partly containing membranous debris or myelin figures. The latter accumulates preferentially in the cytocentrum and is considered to originate from lysosomes. It seems unlikely that glomerular lesions in Masugi nephritis are aggravated by foam cell accumulation.

Immunological analysis of plasminogen activators from cultured human cancer cells

Immunological similarities or differences between urokinase and plasminogen activators from 9 lines of cultured human cancer cells with varying degrees of fibrinolytic activity were examined with antibodies against human urokinase. The antibodies completely inhibited the fibrinolytic activity of 4 lines of gastric cancer, 2 lines of lung cancer, 1 line of urinary bladder cancer and 1 line of renal cancer, indicating that the plasminogen activators from these cell lines were immunologically identical to urokinase. In 5 out of these cell lines, immunological identity was also confirmed by double diffusion analysis. The plasminogen activator from 1 line of lung cancer was found to be immunologically dissimilar to urokinase by a neutralization experiment and double diffusion analysis. These findings indicate that there are at least two immunologically distinguishable forms of plasminogen activators from human cancer cells.