Type-I CdS/ZnS Core/Shell Quantum Dot-Gold Heterostructural Nanocrystals for Enhanced Photocatalytic Hydrogen Generation.

Developing Type-I core/shell quantum dots is of great importance toward fabricating stable and sustainable photocatalysts. However, the application of Type-I systems has been limited due to the strongly confined photogenerated charges by the energy barrier originating from the wide-bandgap shell material. In this project, we found that through the decoration of Au satellite-type domains on the surface of Type-I CdS/ZnS core/shell quantum dots, such an energy barrier can be effectively overcome and an over 400-fold enhancement of photocatalytic H2 evolution rate was achieved compared to bare CdS/ZnS quantum dots. Transient absorption spectroscopic studies indicated that the charges can be effectively extracted and subsequently transferred to surrounding molecular substrates in a subpicosecond time scale in such hybrid nanocrystals. Based on density functional theory calculations, the ultrafast charge separation rates were ascribed to the formation of intermediate Au2S layer at the semiconductor-metal interface, which can successfully offset the energy confinement introduced by the ZnS shell. Our findings not only provide insightful understandings on charge carrier dynamics in semiconductor-metal heterostructural materials but also pave the way for the future design of quantum dot-based hybrid photocatalytic systems.

[Injuries of the biceps-labrum complex : Principles, pathologies and treatment concepts]. / Verletzungen des Bizeps-Labrum-Komplexes : Grundlagen, Pathologien und Behandlungskonzepte.

BACKGROUND: The biceps-labrum complex is prone to acute lesions and degenerative changes due to its anatomical structure and the high load it has to endure. Pathological changes of these structures are common pain generators and can significantly impair shoulder function. Anatomically, the biceps-labrum complex can be divided into three zones: inside, junction and bicipital tunnel. DIAGNOSTIC PROCEDURE: Despite the focused physical examination and advancements in imaging techniques, the exact localization of pathologies remains challenging. Arthroscopy can be used to accurately diagnose inside and junctional pathologies but extra-articular changes in the region of the bicipital tunnel can only be partially visualized. TREATMENT: In cases of unsuccessful conservative treatment and correct indications, a high level of patient satisfaction can be surgically achieved. In young patients an anatomical reconstruction of inside lesions or tenodesis of the long head of the biceps tendon is performed; however, even tenotomy is a valuable option and can achieve equally satisfactory results. Unaddressed pathological changes of the bicipital tunnel can lead to persistence of pain. In clinical procedures performing tenodesis, both the different techniques and the implants used have been found to show similar results. This article describes the anatomical principles, pathological changes, the focused clinical instrumental diagnostics and discusses the different treatment philosophies as well as the outcome according to the recent literature.

[Typical alterations of frozen shoulder in MRI examinations]. / Typische Veränderungen bei der "frozen shoulder" in der bildgebenden MRT-Untersuchung.

Magnetic resonance imaging (MRI) is routinely used for the diagnostic assessment of diseases of the shoulder joint. Depending on the clinical presentation native imaging, intravenous (IV) or intra-articular injection of contrast medium can be performed (MR arthrography). Advances in imaging technology nowadays enable early detection of characteristic changes in the clinical picture of frozen shoulder. These changes typically include thickening of the coracohumeral ligament, the axillary pouch and the capsule at the rotator interval. Furthermore, obliteration of the subcoracoidal fat pad can also be observed. The MRI examinations also show a hyperintensity in the T2-weighted imaging and a contrast enhancement of the joint capsule. The alterations can show a temporal correlation with the clinical symptoms of the patient.

[Proximal humeral fractures-Where do we stand today? : Comments on the "Proximal fracture of the humerus evaluation by randomization (PROFHER)" study]. / Die proximale Humerusfraktur ­ Wo stehen wir heute? : Ein Kommentar zur "Proximal fracture of the humerus evaluation by randomization (PROFHER)"-Studie.

The PROFHER study is a multicenter randomized controlled trial of 250 out of 1250 patients assessed for eligibility with dislocated proximal humeral fractures with involvement of the surgical neck. These patients were randomized either for surgery or conservative treatment. Patients with comorbidities that precluded surgery, lack of mental capacity, luxation fractures or clear indications for surgery from the authors' perspective were excluded. To evaluate the outcome, standardized self-assessment methods were used (patient reported outcome [PRO]), including the Oxford shoulder score (OSS). The results showed no differences in the primary and secondary self-assessment outcome scores after both 2 and 5 years. Although no significant differences could be detected between both groups, no clear statement could be deduced from the PROFHER study with respect to which patients would benefit from an operative treatment. Nevertheless, the PROFHER study provides a valuable and important addition to the literature on this heavily debated topic. The purpose of this review is to critically evaluate the PROFHER study within the existing literature regarding inclusion of patients, fracture treatment and evaluation of the results.

[Torsional malalignment of the humerus]. / Torsionsfehlstellungen am Humerus.

The torsion of the humerus describes the physiological rotation of the humerus around its longitudinal axis. Various clinical and radiological methods for measurement have been described. The computed tomography method is currently the gold standard. The angle between the humeral head axis and the transepicondylar axis is measured. This angle is called retroversion. Values of retroversion vary between 10° and 40°. For the treatment of many humeral pathologies, a precise reconstruction of the anatomical retroversion is required. The retroversion of the humerus has to be considered in shoulder arthroplasty, in fracture situations and also in planning correction of posttraumatic deformities. If an orientation to the original anatomical landmarks of the humerus is no longer possible, an orientation to the contralateral side is recommended.

[Shoulder dislocations in elderly patients]. / Schulterluxationen des älteren Patienten.

In contrast to shoulder dislocations in younger patients, anterior shoulder dislocation in the elderly is often associated with concomitant injuries to the rotator cuff and fractures. There is also frequent involvement of the brachial plexus or peripheral nerves. After closed reduction and a short period of immobilization, physiotherapy should be performed to restore mobility and strength. The evaluation of the rotator cuff is essential for further treatment decisions. The majority of patients are classically treated conservatively. Elderly patients with accompanying rotator cuff lesions and failed conservative therapy can benefit from a surgical intervention. Reconstructive interventions of the rotator cuff should be principally considered; however, some individuals may benefit from a reverse prosthesis in this elderly subgroup of patients. The challenge for the treating surgeon is to exactly define the structural injury of the shoulder (which may include pre-existing lesions) and to select the optimal treatment option.

Fatty degeneration of the deltoid muscle associated with displaced proximal humerus fractures.

INTRODUCTION: The use of reverse shoulder arthroplasty (RSA) has increased dramatically over the last two decades, with many surgeons now indicating RSA for the acute management of displaced proximal humerus fractures (PHF) in the elderly. RSA relies on adequate deltoid muscle function to obtain a good outcome, yet no literature to date exists which discusses preoperative assessment of deltoid structure prior to RSA. The purpose of this study was to assess for preoperative fatty deltoid-degeneration in patients with displaced PHF. MATERIALS AND METHODS: We reviewed the axial CT scans of 100 consecutive patients with a displaced PHF. Fatty degeneration within each of the three deltoid-heads was graded at three levels, according to Goutallier and colleagues. Fractures were classified according to Neer. RESULTS: Seventy-nine percent of the patients were female, 75% showed 3 or 4 parts fractures. The average cross-sectional area of the posterior deltoid was greatest-representing 37%, 40% and 42% of total area at each level, respectively. Severe fatty degeneration (Stages 3 and 4) was observed in the posterior deltoid only (26%). Absence of fatty degeneration (Stage 0) was observed in < 25% of cases. The Inter-Observer-Reliability for the continuous variables proved to be high. CONCLUSION: Preoperative deltoid fatty degeneration is common in displaced PHF in the elderly. Because CT is commonly obtained to assess fracture morphology and for preoperative planning purposes, it is an ideal tool to assess the deltoid additionally. Future studies are warranted to determine whether preoperative fatty infiltration of the deltoid correlates with mid and long term functional outcomes when RSA is used acutely to manage a PHF. LEVEL OF EVIDENCE: Level IV-consecutive case series.

Combined Fluoroscopic and Arthroscopic Detection and Removal of a Foreign Body Lost During Elective Shoulder Arthroscopy: A Case Report.

INTRODUCTION: We report a case of a lost metal platelet from a radiofrequency ablation probe (VAPR VUE Radiofrequency System, Cool Pulse 90, DePuy, Synthes, Switzerland) in the shoulder joint during elective arthroscopic cuff repair. To the best of our knowledge, this kind of an incident during elective arthroscopy has not been described in the literature so far. In addition, we present an algorithm on how to deal with such an incident. CASE REPORT: A 69-year-old woman underwent an arthroscopic subacromial decompression and rotator cuff repair for a torn supraspinatus tendon. While performing the subacromial decompression and after swapping the portals from lateral to posterior, the metal platelet of the electrocautery device got detached from the instrument and lost in the operation field. Several attempts to visualize the lost platelet with the camera failed. Finally, intraoperative fluoroscopic imaging was used to detect the platelet. To confirm the definitive whereabouts of the platelet, two spinal needles were positioned perpendicular to another under x-ray control, both pointing at the missing platelet. After determining the exact location, the platelet could finally be visualized with the camera and removed. Due to this incident, the operation time was extended extensively, and the patient as well as the theatre team was exposed to an unnecessary amount of radiation. CONCLUSION: This report indicates that an extraordinary incident such as the detachment of a component of the arthroscopic equipment during surgery is possible and should be kept in mind by the surgeon. Therefore, we believe that it is essential to perform a test of integrity at least at the end of every operation. In addition, we are presenting an algorithm on how to deal with the situation of a lost foreign body during arthroscopy, which can be applied to any joint.

Arthroscopic Debridement for Irreparable Rotator Cuff Tears.

BACKGROUND: Arthroscopic debridement represents a salvage procedure for irreparable rotator cuff tears. It is important to accurately diagnose the patient for irreparable rotator cuff tears. The diagnosis and the therapeutic options must be explained to the patient. It is mandatory that the patient understands the primary goal of the arthroscopic debridement being reduction of pain, not improving strength or function. METHODS: The procedure consists of 7 distinct steps to debride the soft tissues and alleviate pain. RESULTS: Even though there is a lack of evidence that this procedure is superior to other therapeutic options, it has shown good results in patients with the main complaint of pain. CONCLUSION: The results reported in some studies should, however, be interpreted with caution, taking into consideration the substantial structural damage in irreparable defects.

[Limb salvage or amputation after severe trauma to the lower extremities : Evidence from the LEAP Study]. / Gliedmaßenerhalt oder Amputation nach schwerem Trauma der unteren Extremität : Evidenz aus der LEAP-Studie.

Deciding between reconstruction and primary amputation after severe high-energy trauma to the lower extremities is difficult and consequential. The Lower Extremity Assessment Project (LEAP) prospectively included and investigated patients with severe, limb-threatening injuries below the femur, with third-grade open fractures, defined soft-tissue damage and amputation wounds. This paper aims to review the key results of the LEAP study, which were published in several parts, in due consideration of the newer relevant literature, and to deduce the consequences for clinical practice. The main results are as follows: No score is sufficiently reliable to predict the success of reconstruction. Loss of muscle seems to be more momentous than loss of bone. Any accompanying injuries that should be taken into account in the individual treatment concepts are crucial to the results, in addition to comorbidities and other individual patient-related factors, such as alcoholism, smoking, insurance, and social background. Psychological impairment is frequent after these injuries and should therefore be addressed regularly with regard to rehabilitation.

[Limb salvage versus amputation after severe lower extremity injury : Cases from clinical practice]. / Die Entscheidung zum Gliedmaßenerhalt oder zur Amputation nach schwerem Trauma der unteren Extremität : Fälle aus der klinischen Praxis.

Following severe lower extremity injury, the potential outcome of a salvage procedure might often be questionable. Objective criteria should help in decision-making. From the clinical practice of a level I trauma center, we demonstrate three case reports and approaches following severe lower extremity injury.

[Posttraumatic nonunions and malunions of the proximal humerus. Possibilities and limitations of corrective osteotomy]. / Posttraumatische Fehlstellungen und Pseudarthrosen des proximalen Humerus. Möglichkeiten und Grenzen der Korrekturosteotomie.

BACKGROUND: According to the future demographic trends the incidence of proximal humeral fractures and subsequent posttraumatic malunions and nonunions of the proximal humerus are expected to substantially increase. OBJECTIVES: This article reviews the indications, techniques and outcomes of corrective osteotomy for the treatment of posttraumatic nounions and malunions of the proximal humerus. METHODS: A selective literature search was performed and personal surgical experiences are reported. RESULTS: Malunions of the proximal humerus can occur after both surgical and conservative management of fractures. Due to the complex anatomy of the proximal humerus, malunions have to be systematically assessed regarding epiphyseal and metaphyseal malpositioning. Furthermore, the objective anatomical disorder has to be completely correlated with the subjective patient complaints. The associated soft tissue structures, such as the glenohumeral joint capsule and ligaments, long head of the biceps tendon, rotator cuff and muscles inserting in the metaphysis, can independently cause discomfort to the patient and need to be meticulously identified as such. CONCLUSION: A variety of corrective surgical strategies are available, which are indicated depending on the location and extent of the malunion. The depicted single-cut osteotomy technique represents an elegant therapeutic option for multidimensional deformities of the proximal humerus. Nonunions of the proximal humerus can usually be successfully managed with autologous cancellous bone grafting and locking plate osteosynthesis.

Septic single-stage knee arthrodesis after failed total knee arthroplasty using a cemented coupled nail.

Knee arthrodesis is a potential salvage procedure for limb preservation after failure of total knee arthroplasty (TKA) due to infection. In this study, we evaluated the outcome of single-stage knee arthrodesis using an intramedullary cemented coupled nail without bone-on-bone fusion after failed and infected TKA with extensor mechanism deficiency. Between 2002 and 2012, 27 patients (ten female, 17 male; mean age 68.8 years; 52 to 87) were treated with septic single-stage exchange. Mean follow-up duration was 67.1months (24 to 143, n = 27) (minimum follow-up 24 months) and for patients with a minimum follow-up of five years 104.9 (65 to 143,; n = 13). A subjective patient evaluation (Short Form (SF)-36) was obtained, in addition to the Visual Analogue Scale (VAS). The mean VAS score was 1.44 (SD 1.48). At final follow-up, four patients had recurrent infections after arthrodesis (14.8%). Of these, three patients were treated with a one-stage arthrodesis nail exchange; one of the three patients had an aseptic loosening with a third single-stage exchange, and one patient underwent knee amputation for uncontrolled sepsis at 108 months. All patients, including the amputee, indicated that they would choose arthrodesis again. Data indicate that a single-stage knee arthrodesis offers an acceptable salvage procedure after failed and infected TKA.

[Development of compartment syndrome after intravenous administration of an X-ray contrast medium. Recommendations on acute therapy regimens]. / Kompartmentsyndrom nach paravasaler Applikation von Röntgenkontrastmittel. Empfehlung zum akuten Therapieregime.

The incidence of extravasation of contrast medium is reported in the literature to be between 0.2 % and 0.9 %. A rare consequence of this could be compartment syndrome of the affected limb which requires immediate treatment.We report the case of a patient who developed acute compartment syndrome of the forearm after intravenous injection of radiographic contrast medium in a radiovolar vein during a computed tomography (CT) scan for multiple trauma. The clinical symptoms with pain, loss of range of motion and sensitivity functions, measurement of compartment pressure and radiological images confirmed the diagnosis. After emergency dermatofasciotomy of the forearm the full range of motion and sensitivity functions could be restored.

Computer-assisted navigation of a complex femoral shaft fracture: instruction in three steps--a technical note.

The procedure of computer-assisted navigation of femoral shaft fractures is well described. Nevertheless, its use is less common. An unclear disposal and longer operation times might be two reasons. The aim of this technical note is to render assistance concerning the ideal disposal of the setup.

[Intracondylar segment osteotomy: correction of intra-articular malalignment after fracture of the tibial plateau]. / Intrakondyläre Segmentosteotomie: Korrektur intraartikulärer Fehlstellungen nach Tibiakopffraktur.

Intracondylar deformities after tibial plateau fractures are intra-articular deformities which present within the medial and/or lateral knee compartments. They exist either isolated or in combination with other extra-articular deformities and/or ligament problems. These deformities are complex problems and difficult to treat. While many treatment concepts exist for extra-articular deformities there is limited information available for intra-articular or even intracondylar deformities. Selecting the appropriate procedure for the approach, osteotomy, management of bone defects and cartilage damage is crucial. The authors describe the analysis, planning, treatment and clinical outcome for these rare but difficult problems and present step by step details of the surgical technique.

[Trauma sequalae after complex knee ligament injuries]. / Spätzustände nach komplexer Bandverletzung am Kniegelenk.

Complex ligament injuries can compromise a knee joint and residual conditions comprise stiffness (arthrofibrosis), instability, cartilage damage leading to osteoarthritis and bone deformity. Accurate diagnosis must address the direction and extent of the instability, the severity of any cartilage lesion and an analysis of the axis and bone deformity as well as important cofactors. Therapeutic options are adhesiolysis, ligament reconstruction, cartilage regeneration and axis correction. As a consequence patients mostly profit from the procedure but there is never a return to the functional level that existed before injury.