[Flexor tendon injuries of the hand]. / Beugesehnenverletzungen der Hand.

Flexor tendon injuries of the hand are relatively rare but pose significant challenges to both physician and patient. A thorough clinical evaluation enables flexor tendon lacerations to be identified and classified. The flexor tendons of the hand are divided into five anatomic zones (from distal to proximal). Diagnostics, treatment and prognosis may differ depending on which zone is affected. Early, careful and proficient management is needed to ensure good functional outcomes. Various factors influence the outcome, including location, mechanism of injury, presence of concomitant injuries, time of surgery, quality of tendon repair and the rehabilitation protocol. It is important to inform the patient about the importance of thorough rehabilitation and possible complications. Postoperative scarring and adhesions, infections and secondary tendon ruptures due to insufficient primary repairs are especially challenging and potentially necessitate a lengthy and strenuous secondary repair and rehabilitation process.

Dynamo Enhancement and Mode Selection Triggered by High Magnetic Permeability.

We present results from consistent dynamo simulations, where the electrically conducting and incompressible flow inside a cylinder vessel is forced by moving impellers numerically implemented by a penalization method. The numerical scheme models jumps of magnetic permeability for the solid impellers, resembling various configurations tested experimentally in the von Kármán sodium experiment. The most striking experimental observations are reproduced in our set of simulations. In particular, we report on the existence of a time-averaged axisymmetric dynamo mode, self-consistently generated when the magnetic permeability of the impellers exceeds a threshold. We describe a possible scenario involving both the turbulent flow in the vicinity of the impellers and the high magnetic permeability of the impellers.

Recovery of mechanical detection thresholds after direct digital nerve repair versus conduit implantation.

The purpose of this study was to assess sensory and functional nerve recovery after digital nerve injury in patients with an end-to-end suture (S) or with implantation of a collagen conduit (C) to bridge a nerve gap. Fifteen S and 11 C with a follow-up of 6-36 months and 28 healthy control participants were enrolled. Methods of assessments were quantitative sensory testing, the Disabilities of the Arm, Shoulder and Hand questionnaire (DASH), range of motion and the painDetect questionnaire. After both procedures, sensory profiles showed largely recovered function of C and Aδ fibres but severe loss of Aß-fibre function leading to increased mechanical detection thresholds. There was only minimal allodynia. Severe pain was absent. Patients with conduits reported more functional impairment, especially in work performance, which correlated with the assessed loss of Aß-fibre function. LEVEL OF EVIDENCE: III.

Arthroscopic treatment for ulnar-sided TFCC-tears.

OBJECTIVE: Ruptures of ulnar-sided triangular fibrocartilaginous complex (TFCC) often occur in cases of trauma. Golden standard for diagnosis is the arthroscopy of the wrist. TFCC lesions are classified according to their location if traumatic in origin or if degenerative according to their severity. MATERIALS AND METHODS: Recent literature has focused on the ruptures of ulnar-sided triangular fibrocartilaginous complex. This article describes conservative, operative and arthroscopic surgical techniques to reconstruct the triangular fibrocartilaginous complex and restore distal radioulnar joint stability. RESULTS: The main therapeutic goal should be the stabilization of the DRUJ by reattachment of the torn ligaments in ulnar-sided ruptures to the deep fibers in the fovea. This reinsertion can be performed by transosseous suture, a suture anchor or open. CONCLUSION: Central TFCC tears are typically located close to the sigmoid notch of the radius and are either traumatic or degenerative in origin. While central TFCC lesions are usually treated by arthroscopic debridement using small joint punches or a bipolar high frequency system, the ulnar TFCC avulsions can also be refixed arthroscopically in different techniques.

[Intraosseous Tophaceous Gout of the Hand: Case Report and Literature Review]. / Intraossäre Gichterkrankung der Hand: Falldarstellung und Literaturübersicht.

We report on an intraosseous gout manifestation in the middle phalanx of the left index finger of a 54-year-old patient.

[Wound healing complications in smokers, non-smokers and after abstinence from smoking]. / Wundheilungsstörungen bei Rauchern, Nichtrauchern und nach Rauchstopp.

BACKGROUND: The pulmonary and cardiovascular ramifications of smoking are well documented and this also applies to increased wound healing complications in smokers. The aim of this study was to ascertain whether preoperatively refraining from smoking would affect the incidence of wound healing disorders. MATERIAL AND METHODS: Between 2006 and 2008 a total of 295 patients underwent aesthetic (n = 167) or reconstructive surgery (n = 128). They were divided into three groups: A (n = 98) non-smokers for at least 2 years, B (n = 99) patients who refrained from smoking 6 weeks prior to surgery and C (n = 98) smokers. Smoking abstinence was verified by cotinine tests. Wound healing complications were defined as dehiscent wounds, wound infections, atypical scar formation and adiponecrosis. RESULTS: Smokers developed wound healing complications in 48.2% of cases, non-smokers in 21.0% and patients who had stopped smoking for 6 weeks in 30.8% of cases (p = 0.006). CONCLUSION: Elective surgery should only be performed on non-smokers and smokers who had refrained from smoking for at least 6 weeks to reduce wound healing complications as far as possible.

Patient-individual local SAR determination: in vivo measurements and numerical validation.

Tissue heating during magnetic resonance measurements is a potential hazard at high-field MRI, and particularly, in the framework of parallel radiofrequency transmission. The heating is directly related to the radiofrequency energy absorbed during an magnetic resonance examination, that is, the specific absorption rate (SAR). SAR is a pivotal parameter in MRI safety regulations, requiring reliable estimation methods. Currently used methods are usually based on models which are neither patient-specific nor taken into account patient position and posture, which typically leads to the need for large safety margins. In this work, a novel approach is presented, which measures local SAR in a patient-specific manner. Using a specific formulation of Maxwell's equations, the local SAR is estimated via postprocessing of the complex transmit sensitivity of the radiofrequency antenna involved. The approximations involved in the proposed method are investigated. The presented approach yields a sufficiently accurate and patient-specific local SAR measurement of the brain within a scan time of less than 5 min.

Toward individualized SAR models and in vivo validation.

The specific absorption rate (SAR) is a limiting constraint in sequence design for high-field MRI. SAR estimation is typically performed by numerical simulations using generic human body models. This entails an intrinsic uncertainty in present SAR prediction. This study first investigates the required detail of human body models in terms of spatial resolution and the number of soft tissue classes required, based on finite-differences time-domain simulations of a 3 T body coil. The numerical results indicate that a resolution of 5 mm is sufficient for local SAR estimation. Moreover, a differentiation between fatty tissues, water-rich tissues, and the lungs was found to be essential to represent eddy current paths inside the human body. This study then proposes a novel approach for generating individualized body models from whole-body water-fat-separated MR data and applies it to volunteers. The SAR hotspots consistently occurred in the arms due to proximity to the body coil as well as in narrow regions of the muscles. An initial in vivo validation of the simulated fields in comparison with measured B(1)-field maps showed good qualitative and quantitative agreement.

Lagrangian model for the evolution of turbulent magnetic and passive scalar fields.

In this Brief Report we present an extension of the recent fluid deformation (RFD) closure introduced by Chevillard and Meneveau [L. Chevillard and C. Meneveau, Phys. Rev. Lett. 97, 174501 (2006)] which was developed for modeling the time evolution of Lagrangian fluctuations in incompressible Navier-Stokes turbulence. We apply the RFD closure to study the evolution of magnetic and passive scalar fluctuations. This comparison is especially interesting since the stretching term for the magnetic field and for the gradient of the passive scalar are similar but differ by a sign such that the effect of stretching and compression by the turbulent velocity field is reversed. Probability density functions (PDFs) of magnetic fluctuations and fluctuations of the gradient of the passive scalar obtained from the RFD closure are compared against PDFs obtained from direct numerical simulations.

[Three case reports of frostbite. Management and literature]. / Drei Fallberichte über Erfrierungen. Management und Literatur.

Due to social and demographic changes as well as new leisure activities, the number of frostbite injuries in the general population is on the increase. Because the injuries are primarily located on the hands and feet the consequences for those concerned are devastating. We provide help in grading and introduce concrete therapeutic regimes for frostbite which are illustrated by three case reports from our clinical experience with varying risk profiles.

[Gardner fibroma: case report and discussion of a new soft tissue tumor entity]. / Gardner-Fibrom: Eine neue mesenchymale Tumorentität als Indikatorläsion.

Gardner fibroma represents a rare and recently described soft tissue tumor entity in children and young adults. It consists of haphazardly arranged coarse and hyalinized collagen fibers combined with loosely arranged bland spindle and fibroblastic cells. The case of a 13-year-old male patient with Gardner fibroma and osteoma and multicentric desmoid type fibromatosis in his mother is presented with detection of a (heterozygotic) germline mutation of the APC gene leading to a de novo stop codon (deletion of base pairs 5033-5036). FISH analysis revealed a structural loss of heterozygosity (LOH) in the APC gene on chromosomal locus 5q21 in one out of five analysed desmoids of the mother, no LOH of APC gene in the Gardner fibroma. Gardner fibroma in children and young adults may serve as an indicator lesion for familial adenomatous polyposis (FAP), Gardner syndrome, a familial desmoid type fibromatosis without other manifestations of APC or a new APC gene mutation. For the clinician, this diagnosis should be commented upon accordingly by the surgical pathologist. As the result of a detected APC gene mutation, continuous follow-up for the development of colorectal tumors and desmoid type fibromatosis as well as a familial screening for FAP is recommended.

[Lipoma and atypical lipomatous tumor within the same neoplasia: Evidence for a continuous transition]. / Lipom und atypischer lipomatöser Tumor innerhalb einer Neoplasie: Hinweis für einen kontinuierlichen Ubergang.

The case of a lipomatous tumor with a predominant lipoma component and transition to an atypical lipomatous tumor is presented. A deep-seated soft tissue tumor of the right thigh with a maximum size of 14 cm was resected in a 70-year-old female patient. Corresponding to a comparable macroscopic aspect, the lesion revealed the histological features of an ordinary lipoma without atypia in about 80% of the specimen. In the remaining portion (approximately 20%) histopathology showed an atypical lipomatous tumor (ALT, lipoma-like subtype). Immunohistochemistry for MDM 2 and CDK4 revealed no immunoreactivity in the lipoma component, but within the ALT component. Interphase dual-color fluorescence in situ hybridization showed no amplification of the MDM 2 gene and rarely CDK4 gene amplification within the lipoma component, but high level amplification of MDM 2/CDK4 gene in the ALT area, further supporting the morphologically based diagnosis of a lipomatous tumor including areas of a true lipoma and ALT. This case underlines the concept of a continuous stepwise development of lipomatous soft tissue tumors from benign to malignant counterparts as a biological continuum.

[Identification of genes over-expressed in myxoid/round cell liposarcoma. DNA microarray analysis and immunohistochemical correlation]. / Identifikation überexprimierter Gene in myxoid-rundzelligen Liposarkomen. DNA-Mikroarray-Analyse und immunhistochemische Korrelation.

Myxoid/round cell liposarcoma are characterized by typical chromosomal translocations. This genetic alteration might result in specific gene-expression profiles in this tumor entity. To identify over-expressed genes in myxoid/round cell liposarcoma DNA microarray analysis was performed on four tumors and four samples of adult fat tissue. Genes ret, cdk4, cyclin D2 and c-myc showed over-expression by means of microarray analysis and Northern blotting. Immunohistochemistry demonstrated cytoplasmic localization of associated proteins in 36 different tumors. The localization of ret was seen in endothelial cells of plexiform vasculature in addition to its accumulation in tumor cells (25% of cases). The results show an over-expression of cdk4, cyclin D2, c-myc and ret on both the transcriptional and protein level in myxoid/round cell liposarcoma. For cyclin D2 and ret this finding has not been reported in this tumor type. The increase of ret on transcriptional level might be explained by its expression in endothelium in intratumoral plexiform blood vessels. For the molecular pathogenesis of myxoid/round cell liposarcoma our findings imply the involvement of these four genes in the deregulation of the cell cycle, especially as cdk4 and cyclin D2 are target genes of c-myc.

[Functional reconstruction of the superficial posterior compartment of the leg after tumour ablation in an infant]. / Funktionelle Rekonstruktion des M. triceps surae nach onkologiegerechter Tumorresektion beim Kleinkind.

A 33-month-old female child was diagnosed with a papillary intralymphatic angioendothelioma, a rare type of low-grade angiosarcoma, on the dorsal lower leg. The soleus and gastrocnemius muscle including the Achilles tendon and the subcutis and cutis were resected. The defect was functionally reconstructed by a neurovascular musculocutaneous latissimus dorsi free-flap transfer.

[Complex regional pain syndrome type II or psychogenic painful finger contracture?]. / CRPS Typ II oder psychogene schmerzhafte Fingerkontraktur?

The case is described of a 45-year-old man with fixed contracture of the proximal interphalangeal joints (digits III-IV) after a stab wound injury in the forearm with subsequent compartment syndrome and partial ulnar injury. Despite neurographic recovery there was permanent contracture during rehabilitation, which was classified as psychogenic. Differential diagnostic aspects of this assumption will be discussed on the basis of clinical criteria as well as 3-phase skeleton scintigraphy and MRT for differentiation between complex regional pain syndrome (CRPS) type II and other posttraumatic changes. Readers are encouraged to make their own diagnosis on the basis of the clinical findings and to discuss the case online (http://www.blogs.springer.com/derschmerz).

Effects of maleimide-polyethylene glycol-modified human hemoglobin (MP4) on tissue necrosis in SKH1-hr hairless mice.

OBJECTIVE: Tissue hypoxia after blood loss, replantation and flap reperfusion remains a challenging task in surgery. Normovolemic hemodilution improves hemorheologic properties without increasing oxygen carrying capacity. Red blood cell transfusion is the current standard of treatment with its attendant risks. The aim of this study was to investigate the potential of the chemically modified hemoglobin, MP4, to reduce skin flap necrosis and its effect on selected blood markers and kidneys. MATERIALS AND METHODS: Tissue ischemia was induced in the ear of hairless mice (n=26). Hemodilution was performed by replacing one third of blood volume with the similar amount of MP4, dextran, or blood. The extent of non-perfused tissue was assessed by intravital fluorescent microscopy. RESULTS: Of all groups, MP4 showed the smallest area of no perfusion (in percentage of the ear +/- SEM: 16.3% +/- 2.4), the control group the largest (22.4% +/- 3.5). Leukocytes showed a significant increase in the MP4 and dextran group (from 8.7 to 13.6 respectively 15.4*109/l). On histology no changes of the kidneys could be observed. CONCLUSION: MP4 causes an increase of leukocytes, improves the oxygen supply of the tissue and shows no evidence of renal impairment.

[Importance of specialized centers in diagnosis and treatment of extremity-soft tissue sarcomas. Review of 603 cases]. / Die Bedeutung von Referenzzentren in Diagnose und Therapie von Weichgewebssarkomen der Extremitäten. Auswertung von 603 Fällen.

Correct histopathologic diagnosis is essential for adequate treatment of soft tissue sarcomas. Due to the disorder's rarity, multitude of subgroups, sometimes varying histopathologic appearance, and occasionally inadequate biopsy specimens, diagnosis and grading are challenging. The records of 603 patients with soft tissue tumors of the extremities were reviewed concerning mismatches in primary and definite diagnoses relating to entity, evaluation of primary or recurrent tumor specimens, and the diagnosing pathology institution. For second opinions we referred to the Institute of Pathology of the Ruhr University at the Bergmannsheil Hospital in Bochum, Germany, and to the Pathology Institute of the University of Jena, also in Germany. Liposarcoma and malignant fibrous histiocytoma were the most often diagnosed subgroups at 24% and 22.6%, respectively. In the eight most frequent sarcoma types, malignant peripheral nerve sheath tumors and leiomyosarcoma had the highest rates of false primary diagnosis, 78.4% and 74.2% of cases, respectively. The diagnostic error ratio for nonspecialized pathologists in practice, community hospital pathologists, and academic medical centers was over 60%. For optimal treatment of soft tissue sarcomas, we suggest obtaining expert second opinion to ensure adequate surgical therapy and precise indications for radiation and chemotherapy.

Universal intermittent properties of particle trajectories in highly turbulent flows.

We present a collection of eight data sets from state-of-the-art experiments and numerical simulations on turbulent velocity statistics along particle trajectories obtained in different flows with Reynolds numbers in the range R{lambda}in[120:740]. Lagrangian structure functions from all data sets are found to collapse onto each other on a wide range of time lags, pointing towards the existence of a universal behavior, within present statistical convergence, and calling for a unified theoretical description. Parisi-Frisch multifractal theory, suitably extended to the dissipative scales and to the Lagrangian domain, is found to capture the intermittency of velocity statistics over the whole three decades of temporal scales investigated here.

[Anterolateral thigh flaps for reconstruction of traumatological and oncological defects]. / Der freie ALT-Oberschenkellappen in der traumatologischen und onkologischen Defektdeckung.

BACKGROUND: The anterolateral thigh flap (ALT) has become one of the most preferred options for soft tissue defect reconstruction in Asia with an increasing popularity in Europe. The article presents the authors' experience using the ALT flap for various indications in the upper and lower extremities. METHODS: Between January 2005 and March 2007, 60 free ALT flaps were operated for reconstruction of various soft tissue defects. The causes of soft tissue defects included trauma (13), infection (26), and sarcoma resection (21). We operated on 39 male and 19 female patients with an average age of 50.9 years (range: 16-84 years). RESULTS: The flap survival rate was 95.0% percent (57 of 60 flaps); 5% of the flaps died. The donor site was closed primarily in all cases. Donor site complications were minimal. The average operative time was 282 min (69-544 min). Flap-related major complications occurred in 35.0% of patients including reexploration of the anastomoses and partial flap necrosis. Minor complications, e.g., wound infection, hematoma, and swelling were seen in 23 cases. CONCLUSIONS: Our experience indicates that the free ALT flap is a reliable method for soft tissue defect reconstruction. The use of the ALT offers many advantages such as a long and large caliber vascular pedicle, a large skin island as well as minimal donor site morbidity. The surgery can simultaneously performed by two teams with the patient in a supine position.