Involvement of endothelin/ nitric oxide balance in hepatic ischemia/ reperfusion injury

Introduction: Endothelin (ET) and nitric oxide (NO) act as opponents in the regulation of the hepatic microcirculation. During ischemia/reperfusion (I/R) ET levels are increased, whereas no rise in NO levels is observed. This imbalance may be responsible for microcirculatory disturbances. The aim of this study was to restore the delicate ET/NO balance to maintain the integrity of the hepatic microcirculation and to reduce I/R injury. Methods: Ischemia was induced by crossclamping of the hepatoduodenal ligament for 30 min with portal decompression using a splenocaval shunt (56 Wistar rats, 200–250 g). Sham operation, ischemia and treatment groups with the endothelin receptor antagonist (ERA) bosentan (1 mg/kg body weight i.v.) and the NO donor l-arginine (400 mg/kg body weight i.v.) were performed. For assessment of the microcirculation, sinusoidal perfusion rate, diameters of sinusoids and postsinusoidal venules, leukocyte endothelium interactions and velocity of free-flowing leukocytes were investigated by means of in vivo microscopy 30–90 min after reperfusion. Local hepatic tissue pO₂ was measured prior to ischemia, 30 min and 60 min after reperfusion and aspartate aminotransferase (AST)/alanine aminotransferase (ALT) levels were investigated 2 h and 6 h after reperfusion. Results: After ischemia, sinusoidal and venular diameters were reduced to 76% and 85%, respectively, of sham operation group values (P<0.05), but were maintained at baseline in ERA (98/102%) and NO (102/105%) groups (P<0.05). Increased postischemic leukocyte sticking in sinusoids (144%) and venules (435%) was reduced by therapy to 110/253% (ERA) and 111/ 324% (NO), respectively (P<0.05). Perfusion rate was increased to 93% and 94% compared with 82% in the ischemia group (P<0.05). Concomitant with the improved microcirculation in therapy groups, local hepatic tissue pO₂ was improved 30 min after reperfusion in the ERA (11.0 mmHg) and the l-arginine group (11.5 mmHg) relative to the ischemic group (6.9 mmHg) (P<0.05). In addition, postischemic AST/ALT increase was reduced by therapy. Conclusion: Our results indicate that maintenance of ET/NO balance by blocking ET receptors, as well as providing a NO donor, protects the liver microcirculation and reduces hepatic I/R injury. Received: 14 August 1998 Accepted: 13 October 1998     

Outcome of surgery for ileojejunal neuroendocrine tumors

Purpose

Neuroendocrine tumors (NET) of the ileum/jejunum are rare and may require different treatment options to provide long-term survival. The purpose of the study was to evaluate the outcome of surgery for ileojejunal NET.

Methods

A database of patients that underwent surgery for ileojejunal NETs between 1999 and 2010 was retrospectively analyzed regarding the clinical characteristics, surgical therapy, survival and prognostic factors.

Results

Only six of 97 patients with ileojejunal NET who underwent surgery had localized tumors (stage I/II), 29 had lymph node involvement (stage III) and 62 had distant metastases (stage IV) at the initial presentation. All stage I/II tumors were cured, in comparison to 69 % of stage III and 0 % of stage IV tumors (p = 0.01). Palliative surgery in combination with sequential multimodal treatment regimens resulted in a 5-year survival rate of 63 % in patients with stage IV tumors. A multivariate analysis showed that incomplete resection (HR 2.87; CI 1.18–6.98; p = 0.04) and distant metastases (HR 5.39; 95 % CI 1.23–23.57; p = 0.02) were associated with worse disease-specific survival.

Conclusions

Localized and regionally restricted ileojejunal NETs have an excellent prognosis after surgical treatment. Although stage IV tumors cannot be cured, an aggressive surgical approach in combination with medical or interventional treatment can provide long-term survival.     

Local differences in the trabecular bone structure of the proximal femur depicted with high-spatial-resolution MR imaging and multisection CT

RATIONALE AND OBJECTIVES: The authors performed this study to investigate structural variations in the trabecular bone of the proximal femur at high-resolution magnetic resonance (MR) imaging and high-resolution multisection computed tomography (CT). MATERIALS AND METHODS: Bone mineral density (BMD) was measured in 36 proximal human femur specimens by using dual x-ray absorptiometry. High-resolution MR imaging was performed at 1.5 T with an in-plane spatial resolution of 0.195 x 0.195 mm and a section thickness of 0.3 and 0.9 mm. Multisection CT was performed with an ultra-high-resolution protocol; images were obtained with an in-plane spatial resolution of 0.25 mm and a section thickness of 1 mm. In a subset of these specimens, micro CT was performed with an isotropic spatial resolution of 30 microm. Identical regions of interest (ROIs) were used to analyze images obtained with MR imaging, multisection CT, and micro CT. Trabecular bone structural parameters were obtained, and the parameters from the individual imaging modalities and BMD were correlated. RESULTS: Significant differences concerning the trabecular microarchitecture between the individual ROIs were demonstrated with multisection CT and MR imaging. A number of the correlations between structural parameters derived with multisection CT, MR imaging, micro CT, and BMD measurements were significant. For MR imaging, threshold technique and section thickness had an effect on structural parameters. CONCLUSION: Structural parameters obtained in the proximal femur with multisection CT and high-resolution MR imaging show regional differences. These techniques may be useful for depicting the trabecular architecture in the diagnosis of osteoporosis.     

Posterior cruciate ligament injuries in the athlete: an anatomical, biomechanical and clinical review

Recently, the posterior cruciate ligament (PCL) has become an increasingly popular subject of orthopaedic research and debate. In the past several years, anatomic and biomechanical studies have provided invaluable information concerning the structure and function of the PCL. However, many aspects of PCL injury are still not fully understood. Diagnosis of the injury is often missed because of subtlety of symptoms and clinical findings, and current management strategies of PCL injury have experienced relatively poor clinical outcomes. Controversy exists concerning the most appropriate treatment, especially in cases of isolated PCL injury. The purpose of this review is to present a complete overview of the current knowledge regarding the basic science and clinical aspects of PCL injuries, with a specific focus on the athletic population.     

Chondroblastoma of the acromion mimicking fibrous dysplasia

The authors report the case of a 65-year-old man who presented with an expansive osteolytic lesion in the right acromion, mimicking cystic fibrous dysplasia. Magnetic resonance imaging showed a lesion with intermediate-signal intensity on T1-weighted images and a high-signal intensity on fat suppressed T2-weighted images. The biopsy led to the diagnosis of chondroblastoma. This tumour is rare in flat bones, and may mimic other benign or malignant lesions. It is therefore essential to perform a biopsy in order to obtain a definite diagnosis. The acromion was excised, and replaced with an iliac crest graft.     

Akromioklavikulargelenkverletzungen

There is some controversy over the treatment of acromioclavicular injuries. The use of the Rockwood classification as the basis for decisions on whether operative or nonoperative treatment is indicated is discussed critically, and the authors' preferred operative technique is described and illustrated by examples. We treat injuries classified according to the Rockwood classification as types I and II with conservative methods. In type III injuries the patient's age, job and free time activities determine whether or not surgery is indicated. In the case of type IV or type VI injuries we always perform temporary internal fixation of the acromioclavicular joint, using transarticular K-wire fixation or hookplate osteosynthesis. Satisfactory results of both operative and nonoperative treatment are reported in the literature. The authors' own results are presented.     

Ultra-long-term outcome of surgically treated far-lateral,extraforaminal lumbar disc herniations: a single-center series

Purpose  

Far-lateral extraforaminal lumbar disc herniation is an uncommon cause of nerve root entrapment, and studies addressing the long-term outcome of surgically treated patients are few. The purpose of this study was to analyze the ultra-long-term outcome of patients who were treated via a lateral approach.     

The Munich Shoulder Questionnaire (MSQ): development and validation of an effective patientreported tool for outcome measurement and patient safety in shoulder surgery

ABSTRACT: BACKGROUND: Outcome measurement in shoulder surgery is essential to evaluate the patient safety and treatment efficiency. Currently this is jeopardized by the fact that most patient-reported selfassessment instruments are not comparable. Hence, the aim was to develop a reliable selfassessment questionnaire which allows an easy follow-up of patients. The questionnaire also allows the calculation of 3 well established scoring systems, i.e. the Shoulder Pain and Disability Index (SPADI), the Constant-Murley Score (CMS), and the Disabilities of the Arm, Shoulder and Hand (DASH) Score. The subjective and objective items of these three systems were condensed into a single 30-questions form and validated against the original questionnaires. METHODS: A representative collective of patients of our shoulder clinic was asked to fill in the newly designed self-assessment Munich Shoulder Questionnaire (MSQ). At the same time, the established questionnaires for self-assessment of CONSTANT, SPADI and DASH scores were handed out. The obtained results were compared by linear regression analysis. RESULTS: Fifty one patients completed all questionnaires. The correlation coefficients of the results were r = 0.91 for the SPADI, r = -0.93 for the DASH and r = 0.94 for the CMS scoring system, respectively. CONCLUSIONS: We developed an instrument which allows a quantitative self-assessment of shoulder function. It provides compatible data sets for the three most popular shoulder function scoring systems by one single, short 30-item. This instrument can be used by shoulder surgeons to effectively monitor the outcome, safety and quality of their treatment and also compare the results to published data in the literature.     

Vertebroplasty and Kyphoplasty in Spinal Trauma

Abstract Kyphoplasty and vertebroplasty have become recognized procedures for the treatment of vertebral fractures, especially in patients with osteoporosis. In most cases of osteoporotic spinal vertebral fracture in elderly patients, polymethylmethacrylate (PMMA) cement is used to fill the defect and stabilize the vertebral body. The techniques of vertebroplasty and kyphoplasty differ in the possibility of realignment and reconstruction of the vertebral body and spinal column. Long-term results in terms of integration of the cement and bioreactivity of the vertebral body are still lacking; so, these procedures are still no options in the treatment of younger patients. Vertebroplasty and kyphoplasty show different success in the management of fresh traumatic spine fractures. The acute traumatic vertebral fracture has to be classified sensitively, to find the right indication for cement augmentation. Mild acute compression fractures can be treated by vertebroplasty or kyphoplasty, severe compression and burst fractures by combination of internal fixation and kyphoplasty. The indications for use of biological or osteoinductive cement in spinal fracture management must still be regarded as restricted owing to the lack of basic biomechanical research data. Such cement should not be used except in clinical studies.     

Anatomic single- versus double-bundle ACL reconstruction: a meta-analysis

Purpose

To determine whether anatomic double-bundle anterior cruciate ligament (ACL) reconstruction compared to anatomic single-bundle ACL reconstruction more effectively restored antero–posterior (A–P) laxity, rotatory laxity and reduced frequency of graft rupture. Our hypothesis was that anatomic double-bundle ACL reconstruction results in superior rotational knee laxity and fewer graft ruptures due to its double-bundle tension pattern, compared with anatomic single-bundle ACL reconstruction.

Methods

An electronic search was performed using the PubMed, EMBASE and Cochrane Library databases. All therapeutic trials written in English reporting knee kinematic outcomes and graft rupture rates of primary anatomic double- versus single-bundle ACL reconstruction were included. Only clinical studies of levels I–II evidence were included. Data regarding kinematic tests were extracted and included pivot-shift test, Lachman test, anterior drawer test, KT-1000 measurements, A–P laxity measures using navigation and total internal–external (IRER) laxity measured using navigation, as well as graft failure frequency.

Results

A total of 7,154 studies were identified of which 15 papers (8 randomized controlled trials and 7 prospective cohort studies, n = 970 patients) met the eligibility criteria. Anatomic ACL double-bundle reconstruction demonstrated less anterior laxity using KT-1000 arthrometer with a standard mean difference (SMD) = 0.36 (95 % CI 0.214–0.513, p < 0.001) and less A–P laxity measured with navigation (SMD = 0.29 95 % CI 0.01–0.565, p = 0.042). Anatomic double-bundle ACL reconstruction did not lead to significant improvements in pivot-shift test, Lachman test, anterior drawer test, total IRER or graft failure rates compared to anatomic single-bundle ACL reconstruction.

Conclusion

Anatomic double-bundle ACL reconstruction is superior to anatomic single-bundle reconstruction in terms of restoration of knee kinematics, primarily A–P laxity. Whether these improvements of laxity result in long-term improvement of clinical meaningful outcomes remains uncertain.

Level of evidence

II.