Brachial Artery Dissection Caused by Closed Elbow Dislocation in a Snowboarder: A Case Report and Review of Literature.

This report describes a rare case of brachial artery dissection associated with closed elbow dislocation caused by a snowboarding injury. After peripheral ischaemic findings in the right upper extremity were confirmed, urgent duplex-sonography was performed to diagnose the brachial artery injury. Urgent revascularisation surgery was promptly performed, and arterial dissection was diagnosed by intraoperative findings, in which the adventitia of the brachial artery was intact and the intima was disrupted. In this case, because there was no golden time window before undertaking urgent revascularisation surgery, duplex-sonography was very useful for making an emergency diagnosis. To diagnose arterial dissection, because the adventitia of the brachial artery is intact, it is necessary to perform arteriotomy to identify intimal disruption in the brachial artery. When diagnosing traumatic elbow dislocation, it is important to suspect arterial dissection.

10 aJ-level sensing of nanosecond pulse below 10 THz by frequency upconversion detection via DAST crystal: more than a 4 K bolometer.

By using frequency upconversion detection of terahertz (THz) waves via 4-dimethylamino-N-methyl-4-stilbazolium tosylate (DAST) crystal with an optimized frequency conversion process, ultrahigh sensitivity has been achieved. Direct comparisons with a 4 K bolometer were implemented. By using a simple positive intrinsic negative (PIN) diode without either electrical amplification or optical amplification, frequency upconversion detection can compete with the commercial 4 K bolometer, while by replacing the PIN diode with an avalanche photo diode (APD), it performs more than three orders better than the 4 K bolometer. Based on power calibration, the minimum detectable THz pulse energy is in the order of 10 aJ (9-25 aJ) at 4.3 THz, with a pulse duration of 6 ns. Thus, the minimum number of THz photons that can be detected is down to the order of 10(3) at room temperature. The current THz detection system gives a noise equivalent power (NEP) in the order of 100 fW/Hz(1/2) (50-128 fW/Hz(1/2)). Moreover, by switching current optical detectors, the dynamic range is over six orders.

High-power, single-longitudinal-mode terahertz-wave generation pumped by a microchip Nd:YAG laser [Invited].

We report on the development of a high-peak-power, single-longitudinal-mode and tunable injection-seeded terahertz-wave parametric generator using MgO:LiNbO3, which operates at room temperature. The high peak power (> 120 W) is enough to allow easy detection by commercial and calibrated pyroelectric detectors, and the spectral resolution (< 10 GHz) is the Fourier transform limit of the sub-nanosecond terahertz-wave pulse. The tunability (1.2-2.8 THz) and the small footprint size (A3 paper, 29.7 × 42 cm) are suitable for a variety of applications.

Relationship of the menstrual cycle phase to anterior cruciate ligament injuries in teenaged female athletes.

INTRODUCTION: Anterior cruciate ligament (ACL) injuries are more common among female athletes compared to male athletes. Several studies have been reported to explain the gender difference in ACL injury rates and several risk factors underlying gender disparity are believed to exist. Hormonal effects are considered to be one of the etiological factors for female non-contact ACL injuries. The objectives of this study were to determine if ACL injuries occurred randomly or correlated with a specific phase of the female menstrual cycle in teenaged female athletes and then to determine if pre-menstrual and menstrual dysfunctions influenced these ACL injuries. MATERIALS AND METHODS: Eighteen of 37 consecutive female athletes, with ACL injuries, met the study criteria: teenage, with regular menstrual cycle, and non-contact injury. The menstrual history, athletic activity, and injury history were collected. RESULTS: Seventy-two percent of the subjects had premenstrual symptoms and 83% had menstrual symptoms. The subjective activity level at the follicular phase was significantly lowest between the phases. A significant statistical association was found between the phase of the menstrual cycle and ACL injuries (P = 0.0002). There were more injuries in the ovulatory phase than expected, and fewer injuries occurred in the other phases. CONCLUSION: The results showed a significant increase in non-contact ACL injuries in teenage female athletes during the ovulatory phase of the menstrual cycle and the subjective activity level and the premenstrual and menstrual symptoms might not affect the likelihood of the injuries. These findings suggest that sex hormones might play a role in the incidence of female non-contact ACL injuries.

Bilateral osteochondritis dissecans of the lateral trochlea of the femur: a case report.

Osteochondritis dissecans of the bilateral trochlea of femur is unusual case for orthopedic surgeon. The patient was a healthy 15-year-old male with symptomatic osteochondritis dissecans of the bilateral distal lateral femoral condyle of the trochlea. A surgery on the bilateral knee joints was performed simultaneously. The osteochondral free fragment of the right knee was resected by a minimum open surgery after arthroscopic evaluation. In the left knee the fragment was stabilized with multiple cortical bone pegs harvested from the proximal tibia. The surgery was successful, and the patient was able to play basketball 3 months postoperatively. The course of the right knee is currently under careful observation because of the possibility of recurrence. The left knee has remained in an excellent condition for 18 months following surgery with bone pegs.

Plantar pressure distribution during gait in athletes with functional instability of the ankle joint: preliminary report.

This study addressed the hypothesis that gait characteristics differ between normal subjects and athletes suffering from functional instability (FI) of the ankle joint. FI of the ankle joint is one of the most common residual disabilities after an acute ankle sprain. However, the influences of the FI of the ankle joint on the gait characteristics are not well understood. Athletes suffering from FI of the ankle joint and healthy control subjects were examined. Pressure, area, and force during gait were measured using a pressure measuring system. These in vivo plantar pressure measurements were performed during free walking. The foot angle and the pronation-supination index were calculated. Those in the FI group were found to exhibit a significantly lower dynamic foot angle and a greater pronation-supination index at the midsupport phase of gait than those in the control group. The results showed increased adduction-supination of the foot at the stance phase of gait in those with FI of the ankle joint.

Immunohistochemical collagen analysis of the most superficial layer in adult articular cartilage.

We investigated immunohistochemically the collagen type of the most superficial layer in 10 normal adult human articular cartilage specimens obtained from eight femoral heads and one each of the femoral condyle and the talus using routine light microscopy and polarizing microscopy. A membrane-like structure with strong bire-fringence covering the articular surface was observed under polarizing microscopy in each specimen. This structure was stained with anti-type I and anti-type III collagen antibodies but not with anti-type II collagen antibody. This immunohistochemical finding was identical to that in synovial tissue. The results of this study confirm that the most superficial layer of adult normal articular cartilage consists not of type II collagen but of types I and III, and that this layer is absolutely independent from its deeper layer.

Development of the attachment zones in the rat anterior cruciate ligament: changes in the distributions of proliferating cells and fibrillar collagens during postnatal growth.

The development of the attachment zones of the anterior cruciate ligament (ACL) is an important consideration when examining the structural properties. The aim of this study was to elucidate the morphological changes and the distribution of proliferating cells and collagen types I, II and III at the attachment zones of the rat ACL during postnatal growth. The majority of proliferating cell nuclear antigen (PCNA) immunostained cells were noted near the ligament insertion, especially at the tibial site, and these cells gradually changed to fibrochondrocyte-like cells but still produced collagen types I and III at birth until one month old when rapid longitudinal growth of the ACL took place. After one month when the rate of the ligament growth decreased to one thirtieth of that during the first month and the epiphyseal cartilage at the attachment zone had been replaced by bone, these fibrochondrocyte-like cells began to produce collagen type II and reveal safranin O staining. The immunolabelling pattern to collagen type III was similar to that of PCNA immunostaining during the growth phase. Our findings show that the fibrochondrocytes at the attachment zone may develop from the ligament cells and act as a growth zone for the ligament during the period of ligament growth, and that subsequently, these cells begin to synthesis collagen type II and proteoglycans after epiphyseal ossification. These observations mainly occurred at the tibial attachment zone.