Pathologic Fracture as Presentation of Generalized Lymphangiomatosis in an Eight-Year-Old: A Case Report and Literature Review.

Pathologic fractures commonly occur secondary to abnormal skeletal physiology in the context of benign or malignant lesions. Rarely, pathologic fractures may occur in the context of a lymphatic abnormality, such as generalized lymphangiomatosis. This rare disorder is characterized by variable presentations in a broad age range of patients. By understanding the effect of widespread lymphatic anomalies on various organ systems, clinicians will be able to make this diagnosis earlier and with more certainty.

Imperceptible Supercapacitors with High Area-Specific Capacitance.

Imperceptible electronics will make next-generation healthcare and biomedical systems thinner, lighter, and more flexible. While other components are thoroughly investigated, imperceptible energy storage devices lag behind because the decrease of thickness impairs the area-specific energy density. Imperceptible supercapacitors with high area-specific capacitance based on reduced graphene oxide/polyaniline (RGO/PANI) composite electrodes and polyvinyl alcohol (PVA)/H2 SO4 gel electrolyte are reported. Two strategies to realize a supercapacitor with a total device thickness of 5 µm-including substrate, electrode, and electrolyte-and an area-specific capacitance of 36 mF cm-2 simultaneously are implemented. First, the void volume of the RGO/PANI electrodes through mechanical compression is reduced, which decreases the thickness by 83% while retaining 89% of the capacitance. Second, the PVA-to-H2 SO4 mass ratio is decreased to 1:4.5, which improves the ion conductivity by 5000% compared to the commonly used PVA/H2 SO4 gel. Both advantages enable a 2 µm-thick gel electrolyte for planar interdigital supercapacitors. The impressive electromechanical stability of the imperceptible supercapacitors by wrinkling the substrate to produce folds with radii of 6 µm or less is demonstrated. The supercapacitors will be meaningful energy storage modules for future self-powered imperceptible electronics.

Diagnostic shortcomings of magnetic resonance arthrography to evaluate partial rotator cuff tears in adolescents.

BACKGROUND: Recent evidence suggests an increase in the incidence of partial articular-sided rotator cuff tears in adolescent athletes, but the accuracy of diagnostic studies has not been previously assessed in this cohort. This study was performed to assess the ability of magnetic resonance imaging with arthrography (MRIa) to diagnose partial rotator cuff (PRC) pathology in the adolescent age group. METHODS: All patients under the age of 19 years who underwent shoulder arthroscopy, between August 2008 and August 2010, were grouped based on the presence of a PRC tear diagnosed by either MRIa or arthroscopy. The control cohort included children without evidence of an intraoperative PRC. Surgical findings were then correlated with the preoperative MRIa findings and the accuracy of MRIa reading. Interclass coefficient was then determined for the MRIa reviewers. RESULTS: Thirty-one of 89 adolescents (mean age, 15.9 y; 36% girls and 64% boys) who underwent arthroscopic shoulder surgery were found to have radiographic or arthroscopic evidence of a PRC injury. There were 17 boys and 14 girls in the PRC group, with a mean age of 15.6 years. The PRC injuries involved either the supraspinatus tendon, infraspinatus tendon, or both. MRIa was 44% sensitive and 87% specific, with a positive predictive value of 64% and a negative predictive value of 74% with arthroscopic findings used as the gold standard. The ICC between reviewers was κ=0.57, with an absolute agreement of 84%. CONCLUSIONS: The overall diagnostic accuracy of the MRIa with regard to adolescent PRC injuries was 72%. MRIa was found to be specific, but not sensitive for the diagnosis of this pathology. The high false-negative rate seen in this adolescent cohort indicates that a PRC injury may be present even with a negative MRIa. Therefore, if clinical suspicion indicates a PRC injury, then the treating physician should consider management for rotator cuff pathology despite negative MRIa findings. LEVEL OF EVIDENCE: Level III--retrospective cohort study.

Hip pathology in the adolescent athlete.

Hip injuries in young athletes are being diagnosed with increasing frequency. Improvements in diagnostic imaging and surgical technologies have helped facilitate the diagnosis of intra- and extra-articular derangements that were previously untreated in this age group. Athletic injuries of the hip in the young athlete encompass both osseous and soft-tissue etiologies, which can be the result of a single traumatic event or repetitive microtrauma or may be associated with an underlying pediatric hip disorder. Without accurate diagnosis and management, these injuries may result in debilitating consequences. This article will review the more common causes of hip and groin pain in the adolescent athlete, as well as advances in diagnostic and therapeutic interventions.

Partial rotator cuff tears in adolescents: factors affecting outcomes.

INTRODUCTION: In the adult population, rotator cuff tears are common and established treatment methods yield satisfactory results. In adolescents, however, these injuries are uncommon and few treatment methods and outcome reports exist. The purpose of this study was to examine a series of adolescent rotator cuff tears, identify associated pathology, and report treatment outcomes. METHODS: A retrospective comparative analysis of adolescent patients treated for rotator cuff tears diagnosed by magnetic resonance imaging (MRI) or arthroscopy between 2008 and 2010 was performed. Patients were divided by treatment rendered: nonoperative or operative. Demographic and diagnostic variables were compared between the 2 groups. After release to full activity, 3 patient outcome measures were obtained: QuickDASH (Disability of the Arm, Shoulder, and Hand), QuickDASH Sports module, and the Single Assessment Numerical Evaluation (SANE). RESULTS: Fifty-three adolescents (38 boys and 15 girls) with a mean age of 15.8 years (8.8 to 18.8 y) met the inclusion criteria. All rotator cuff tears were partial articular-sided tendon avulsions, and surgical treatment (when required) consisted of debridement to stable edges. All patients underwent a trial of at least 6 weeks of physical therapy, with 57% failing to improve and requiring subsequent surgery. In the patients that were treated nonoperatively, 39% were diagnosed with associated pathology based on MRI findings, whereas operative patients exhibited an associated pathology rate of 70%. Patients with MRI-diagnosed associated pathology were 1.8 times more likely (95% confidence interval, 1.02-3.13, P=0.025) to require surgery compared with those without MRI-identified associated pathology. Nineteen patients (13 operative, 6 nonoperative) completed the outcome questionnaires at a mean 16.9 months after treatment. QuickDASH, SANE, and QuickDASH Sports module scores were not statistically different between nonoperative and operative treatment groups (7.5 vs. 8.1, P=0.90; 85.3 vs. 80.6, P=0.47; and 5.2 vs. 19.5, P=0.39, respectively). All outcome measures exhibited significant correlations with one another, with the strongest correlation being a negative association between SANE and Sports module scores (r=-0.76, P=0.001). DISCUSSION: Isolated partial articular-sided tendon avulsion injuries may be successfully treated with physical therapy, with return to sports expected; however, if associated pathology was present then nonoperative treatment was less successful. Improvement in pain and activities of daily living can be achieved with surgery after failed conservative management for rotator cuff injuries; however, the adolescent athlete will often have residual shoulder complaints during sports participation. LEVEL OF EVIDENCE: Level III-retrospective cohort study.

Posttraumatic Chondrocyte Apoptosis in the Murine Xiphoid.

OBJECTIVE: To demonstrate posttraumatic chondrocyte apoptosis in the murine xiphoid after a crush-type injury and to ultimately determine the pathway (i.e., intrinsic or extrinsic) by which chondrocytes undergo apoptosis in response to mechanical injury. DESIGN: The xiphoids of adult female wild-type mice were injured with the use of a modified Kelly clamp. Postinjury xiphoid cartilage was analyzed via 3 well-described independent means of assessing apoptosis in chondrocytes: hematoxylin and eosin staining, terminal deoxynucleotidyl transferase dUTP nick end labeling assay, and activated caspase-3 staining. RESULTS: Injured specimens contained many chondrocytes with evidence of apoptosis, which is characterized by cell shrinkage, chromatin condensation, nuclear fragmentation, and the liberation of apoptotic bodies. There was a statistically significant increase in the number of chondrocytes undergoing apoptosis in the injured specimens as compared with the uninjured specimens. CONCLUSIONS: Chondrocytes can be stimulated to undergo apoptosis as a result of mechanical injury. These experiments involving predominantly cartilaginous murine xiphoid in vivo establish a baseline for future investigations that employ the genetic and therapeutic modulation of chondrocyte apoptosis in response to mechanical injury.

Unwitnessed magnet ingestion in a 5 year-old boy leading to bowel perforation after magnetic resonance imaging: case report of a rare but potentially detrimental complication.

BACKGROUND: The ingestion of non-food items in children is a relatively common event, often unwitnessed, unknown, and unreported. For those children brought in for medical evaluation, less than 10% require intervention, and only 1% require surgery. This, however, is not the case for magnet ingestion. Magnets, in plurality, can become attracted to one another through intestinal walls, causing a variety of surgical emergencies. CASE PRESENTATION: We present a case of unwitnessed multiple magnet ingestion in a 5 year-old boy who presented to the emergency department with the atypical chief complaint of neck pain. The diagnostic work-up including a neck magnetic resonance imaging (MRI) potentially led to bowel perforations managed definitely by a subsequent exploratory laparotomy. The child had an uneventful postoperative recovery and was discharged to home upon surgical recovery. CONCLUSIONS: Institutions should make all possible efforts to attempt to prevent such potential life-threatening circumstances. We propose a screening tool that can further enhance the care of children who cannot or do not report unwitnessed magnetic ingestion prior to MRI evaluation.

Medial epicondyle fractures in the pediatric population.

Humeral medial epicondyle fractures in the pediatric population account for up to 20% of elbow fractures, 60% of which are associated with elbow dislocation. Isolated injuries can occur from either direct trauma or avulsion. Medial epicondyle fractures also occur in combination with elbow dislocations. Traditional management by cast immobilization increasingly is being replaced with early fixation and mobilization. Relative indications for surgical fixation include ulnar nerve entrapment, gross elbow instability, and fractures in athletic or other patients who require high-demand upper extremity function. Absolute indications for surgical intervention are an incarcerated fragment in the joint or open fractures. Radiographic assessment of these injuries and their true degree of displacement remain controversial.

Underestimation of labral pathology in adolescents with anterior shoulder instability.

BACKGROUND: Shoulder instability is not uncommon in the adolescent athlete, and yet the ability for either clinical examination or magnetic resonance imaging (MRI) with arthrogram to accurately detect pathology in this younger population has not been elucidated yet. This study was performed to characterize the ability of physical examination and MRI to identify intra-articular pathology in those adolescents suspected of having anterior shoulder instability. METHODS: A retrospective review of patients treated over a year between 2008 and 2009 was undertaken. Included were patients with detailed physical examinations, preoperative MRI, and shoulder arthroscopy. Patients with previous shoulder surgery for instability, those who underwent surgery for brachial plexopathy, and those without an MR arthrogram were excluded. Demographics, age, sex, sports participation, and physical examination findings were recorded. Diagnostic arthroscopy findings were then compared with the clinical suspicion (based on history and physical examination) and the MRI findings. Imaging and arthroscopic results were categorized as anterior tear, anterior + tear (anterior tear with extension superior or posterior), other intra-articular pathology, or normal examination. An anterior instability cohort was then created by applying an exclusion criterion against patients without a clinical suspicion of anterior instability. RESULTS: Forty-three patients were included after application of all inclusion and exclusion criteria. The clinical suspicion of anterior labral tear was 59% accurate (positive predictive value of 79%) and the MRI was 86% accurate (positive predictive value of 95%). Among all included patients, 23 adolescents (24 shoulders) were identified with a preoperative clinical suspicion of anterior labral tear based on history, physical examination, and plain radiographs (8 girls/15 boys). Mean age at surgery was 15.9 years (13.3 to 18.8). In this suspected anterior labral tear cohort, 79% had arthroscopic confirmation of the clinical suspicion, but 58% had extension of the labral tear either superior or posterior. MRI was 100% sensitive, 55% specific for an isolated anterior tear; yet, the MRI was 46% sensitive, 100% specific at identifying the larger anterior + labral tears. A statistically significant difference existed between the extent of the labral tear found on MRI and that found at the time of surgery (P=0.006), with tears of the glenoid labrum often extending beyond what was predicted by MRI. CONCLUSION: Clinical suspicion and preoperative MR arthrogram of anterior instability in adolescents seem to detect evidence of labral pathology but have limited success in identifying the true extent of the labral pathology as proven by arthroscopy. LEVEL OF EVIDENCE: Level III Diagnostic Studies.

Mechanical compression of articular cartilage induces chondrocyte proliferation and inhibits proteoglycan synthesis by activation of the ERK pathway: implications for tissue engineering and regenerative medicine.

Articular cartilage is recalcitrant to endogenous repair and regeneration and is thus a focus of tissue engineering and regenerative medicine strategies. A prerequisite for articular cartilage tissue engineering is an understanding of the signal transduction pathways involved in mechanical compression during trauma or disease. We sought to explore the role of the extracellular signal-regulated kinase 1/2 (ERK 1/2) pathway in chondrocyte proliferation and proteoglycan synthesis following acute mechanical compression. Bovine articular cartilage explants were cultured with and without the ERK 1/2 pathway inhibitor PD98059. Cartilage explants were statically loaded to 40% strain at a strain rate of 1/s for 5 s. Control explants were cultured under similar conditions but were not loaded. There were four experimental groups: (a) no load, without inhibitor; (b) no load, with the inhibitor PD98059; (c) loaded, without the inhibitor; and (d) loaded, with the inhibitor PD98059. The explants were cultured for varying durations from 5 min to 5 days and were then analysed by biochemical and immunohistochemical methods. Mechanical compression induced phosphorylation of ERK 1/2, and this was attenuated with the ERK 1/2 pathway inhibitor PD98059 in a dose-dependent manner. Chondrocyte proliferation was increased by mechanical compression. This effect was blocked by the inhibitor of the ERK 1/2 pathway. Mechanical compression also led to a decrease in proteoglycan synthesis that was reversed with inhibitor PD98059. In conclusion, the ERK 1/2 pathway is involved in the proliferative and biosynthetic response of chondrocytes following acute static mechanical compression.