Structural connections between the noradrenergic and cholinergic system shape the dynamics of functional brain networks

Complex cognitive abilities are thought to arise from the ability of the brain to adaptively reconfigure its internal network structure as a function of task demands. Recent work has suggested that this inherent flexibility may in part be conferred by the widespread projections of the ascending arousal systems. While the different components of the ascending arousal system are often studied in isolation, there are anatomical connections between neuromodulatory hubs that we hypothesise are crucial for mediating key features of adaptive network dynamics, such as the balance between integration and segregation. To test this hypothesis, we estimated the strength of structural connectivity between key hubs of the noradrenergic and cholinergic arousal systems (the locus coeruleus [LC] and nucleus basalis of Meynert [nbM], respectively). We then asked whether the strength of structural LC and nbM inter-connectivity was related to individual differences in the emergent, dynamical signatures of functional integration measured from resting state fMRI data, such as network and attractor topography. We observed a significant positive relationship between the strength of white-matter connections between the LC and nbM and the extent of network-level integration following BOLD signal peaks in LC relative to nbM activity. In addition, individuals with denser white-matter streamlines interconnecting neuromodulatory hubs also demonstrated a heightened ability to shift to novel brain states. These results suggest that individuals with stronger structural connectivity between the noradrenergic and cholinergic systems have a greater capacity to mediate the flexible network dynamics required to support complex, adaptive behaviour. Furthermore, our results highlight the underlying static features of the neuromodulatory hubs can impose some constraints on the dynamic features of the brain.

Generation of an equine biobank to be used for Functional Annotation of Animal Genomes project

The Functional Annotation of Animal Genomes (FAANG) project aims to identify genomic regulatory elements in both sexes across multiple stages of development in domesticated animals. This study represents the first stage of the FAANG project for the horse, Equus caballus. A biobank of 80 tissue samples, two cell lines and six body fluids was created from two adult Thoroughbred mares. Ante-mortem assessments included full physical examinations, lameness, ophthalmologic and neurologic evaluations. Complete blood counts and serum biochemistries were also performed. At necropsy, in addition to tissue samples, aliquots of serum, ethylenediaminetetraacetic acid (EDTA) plasma, heparinized plasma, cerebrospinal fluid, synovial fluid, urine and microbiome samples from all regions of the gastrointestinal and urogenital tracts were collected. Epidermal keratinocytes and dermal fibroblasts were cultured from skin samples. All tissues were grossly and histologically evaluated by a board-certified veterinary pathologist. The results of the clinical and pathological evaluations identified subclinical eosinophilic and lymphocytic infiltration throughout the length of the gastrointestinal tract as well as a mild clinical lameness in both animals. Each sample was cryo-preserved in multiple ways, and nuclei were extracted from selected tissues. These samples represent the first published systemically healthy equine-specific biobank with extensive clinical phenotyping ante- and post-mortem. The tissues in the biobank are intended for community-wide use in the functional annotation of the equine genome. The use of the biobank will improve the quality of the reference annotation and allow all equine researchers to elucidate unknown genomic and epigenomic causes of disease.

Unified neural field theory of brain dynamics underlying oscillations in Parkinson's disease and generalized epilepsies

The mechanisms underlying pathologically synchronized neural oscillations in Parkinson's disease (PD) and generalized epilepsies are explored in parallel via a physiologically-based neural field model of the corticothalamic-basal ganglia (CTBG) system. The basal ganglia (BG) are approximated as a single effective population and their roles in the modulation of oscillatory dynamics of the corticothalamic (CT) system and vice versa are analyzed. In addition to normal EEG rhythms, enhanced activity around 4 Hz and 20 Hz exists in the model, consistent with the characteristic frequencies observed in PD. These rhythms result from resonances in loops formed between the BG and CT populations, analogous to those that underlie epileptic oscillations in a previous CT model, and which are still present in the combined CTBG system. Dopamine depletion is argued to weaken the dampening of these loop resonances in PD, and network connections then explain the significant coherence observed between BG, thalamic, and cortical population activity around 4-8 Hz and 20 Hz. Parallels between the afferent and efferent connection sites of the thalamic reticular nucleus (TRN) and BG predict low dopamine to correspond to a reduced likelihood of tonic-clonic (grand mal) seizures, which agrees with experimental findings. Furthermore, the model predicts an increased likelihood of absence (petit mal) seizure resulting from pathologically low dopamine levels in accordance with experimental observations. Suppression of absence seizure activity is demonstrated when afferent and efferent BG connections to the CT system are strengthened, which is consistent with other CTBG modeling studies. The BG are demonstrated to have a suppressive effect on activity of the CTBG system near tonic-clonic seizure states, which provides insight into the reported efficacy of current treatments in BG circuits. Sleep states of the TRN are also found to suppress pathological PD activity in accordance with observations. Overall, the findings demonstrate strong parallels between coherent oscillations in generalized epilepsies and PD, and provide insights into possible comorbidities.

[Transarticular C1-C2 screw fixation: results of unstable odontoid fractures and pseudarthrosis in the elderly]

BACKGROUND

Transarticular dorsal screw fixation of atlantoaxial instability in the elderly is seldom described in the literature. This study presents the results of this technique in patients aged at least 70 years. A modified method of indirect screw fixation is used in which soft tissue dissection is reduced compared to the classic procedure.

PATIENTS AND METHODS

Between 1998 and 2005 a total of 36 patients with acute or chronic traumatic instability of the atlantoaxial complex were treated surgically. The average age was 80.1 years (70-93 years). Seven patients (19.4%) had associated injuries. The operative technique was standard. The duration of radiological follow-up averaged 23 months (12-57 months) whereas clinical follow-up was for 38 months (12-72 months).

RESULTS

There were no intraoperative complications. Of the total 72 screws inserted, 2 (2.8%) proved to be incorrectly positioned. There were complications not associated with the procedure in 16 patients (44.4%). Nosocomial infections and falls were the most common complications. Two deaths occurred within the first postoperative month. Four more patients died in the follow-up period as a result of diseases not associated with the trauma. Of the 30 surviving patients, 28 (93.3%) were followed up clinically and radiologically. Bony dorsal fusion was documented in every patient followed up. Further operation on the cervical spine was not required in any patient.

CONCLUSION

The presented technique of transarticular C1-C2 screw fixation is associated with reliable fusion rates and good functional results. The procedure can be recommended for atlantoaxial instability in the elderly.

A Comprehensive Test System to Identify Suitable Antibodies Against p53 for Immunohistochemical Analysis of Canine Tissues

The tumour suppressor p53 is commonly detected in tissues of companion animals by means of antibodies raised against the human protein. The following three-step procedure was devised to test the suitability of such antibodies for immunohistochemistry on canine tissues. (1) Western blot and immunohistochemical analyses on bacterially expressed recombinant canine protein to assess human-to-canine cross-reactivity. (2) Immunohistochemistry of cultured, UVB-irradiated canine keratinocytes to evaluate suitability for detection of endogenous p53. (3) Immunohistochemistry on tissue arrays to further substantiate suitability of the antibodies on a panel of normal and neoplastic human and canine tissues. Five of six antibodies cross-reacted with recombinant canine p53. Three of these (PAb122, PAb240, CM-1) also immunolabelled stabilized wild type p53 in cell cultures and elicited a consistent, characteristic labelling pattern in a subset of tumours. However, two alternative batches of polyclonal antibody CM-1 failed to detect p53 in cell cultures, while showing a characteristic labelling pattern of a completely different subset of tumours and unspecific labelling of normal tissues. The test system described is well suited to the selection of antibodies for immunohistochemical p53 detection. The results emphasize the need to include appropriate controls, especially for polyclonal antibodies.

[Surgical management of spondylodiscitis. An analysis of 78 cases]

Spondylodiscitis is a rare bacterial infection of the spine with an inflammatory, destructive course. To obtain further information on the therapeutic management and clinical course of spondylodiscitis, we retrospectively investigated 78 patients after surgical intervention. Mean age was 64 years (+/-4.6 years; range 21-80 years), the mean length of stay 49 days (+/-8.2 days; 3-121 days) including 24 days (+/-4.7 days; 0-112 days) in ICU. In hospital mortality was 9%. The cervical spine was affected in 10%, the thoracic spine in 35% and the lumbar/sacral spine in 55% of patients. Abscess formation occurred in 65% and destruction of the vertebral body in 74%. A total of 75% of patients presented with neurological deficits which could be improved by surgical intervention in 82% of cases. 24 patients were treated by ventral debridement and stabilization alone, 20 patients with a combined dorsoventral method. Most patients (n=34) were stabilized via dorsal bridging instrumentation without ventral debridement of the focus. Of this group, 23 patients were initially scheduled for secondary ventral debridement but complete healing was achieved prior to this, so further surgical therapy was unnecessary. Successful cure was obtained in 92% of cases. Based on our findings, we favor a split surgical approach: initially with dorsal internal fixation only. Abscesses can be drained percutaneously. Ventral debridement and stabilization is only recommended if insufficient stability can be obtained by dorsal fixation alone, as shown by the persistence of infection or pain.

Die avaskuläre Kapitatumnekrose bei Sportlern

The possibility of osteonecrosis of the carpal bones should always be considered when athletes present with pain of unknown origin in the hand and wrist, in particular, if they are participating in sports such as gymnastics or weight-lifting that involve extreme loading of the wrist with axial compression and microtrauma. This sort of extreme loading of the wrist combined with a constitutionally "weak" blood supply to the individual carpal bones may lead to the formation of osteo-necrotic zones. A treatment method that can produce excellent results, depending on the pathomorphology, is available in the form of vascularized bone grafting.

Role of subtilisin-like convertases in cadherin processing or the conundrum to stall cadherin function by convertase inhibitors in cancer therapy

Cadherins are a family of intercellular adhesion receptors. Produced as inactive precursors, they become functional adhesion molecules after proteolytic cleavage by subtilisin-like pro-protein convertases (PCs). Owing to their activation and assembly into multiprotein adhesion complexes at sites of cell contacts, adhesion-competent cadherins are prerequisite for tissue integrity. In recent years evidence has accumulated that intercellular junctions not only provide mechanical linkage, but in addition are potent modulators of signalling cascades. This infers a biological role to intercellular adhesion complexes that is significantly more complex and powerful. Currently, the broad implications of disturbances in somatic tissue adhesion components are only just beginning to emerge. Prominent examples of adhesion defects include autoimmune diseases, or tumour invasion and metastasis and malignant transformation. This review reports on our current knowledge of cadherin function and their maturation by pro-protein convertases, and puts special emphasis on the consequences of pro-protein convertase inhibition for epithelial tissue homeostasis.

[Osteomyelitis of the spine]

Spinal infections are rare, occurring most often in elderly patients with urinary tract infections or diabetes. With the increasing number of patients with immune suppression, and also the increasing number of immigrants in the population, spinal infections are seen more frequently, especially in young adults. Typically spinal infections are monomicrobial, Staphylococcus aureus being the most common organism. Hematogenous spread of bacteria through the arterial paravertebral collateral vessels into the subchondral bone marrow of the vertebral bodies is the most common source of infection. Clinical presentation is often nonspecific. Important diagnostic measurements are laboratory studies, radiological evaluation including MR image scans, and CT-guided percutaneous biopsy of the lesion for microbiological studies. The management of spinal infections consists of antimicrobial therapy over 6-8 weeks. Surgical intervention is indicated in neurologically compromised patients for spinal instability and abscesses.

[Patellectomy after trauma: is there a correlation between the timing and the clinical outcome]

AIM OF THE STUDY

Is there a correlation between the timing of patellectomy after trauma in crush injuries and the clinical outcome?

METHODS

Retrospective analysis of 21 patients who had undergone patellectomy after trauma.

RESULTS

In 12 patients (57.1%) a primary patellectomy was performed within 4 weeks after the fracture; in the remaining 9 (42.9%) patients the procedure was performed after an average of 21 months (range 2-72). Nineteen patients could be followed up after 9.3 years (range 3-18). In 10 of these, patellectomy had been performed primarily. The HSS Knee Score was 68.4 points (range 39-83) on average for all patients. For patients with a primary patellectomy the score was 71 points (range 54-83), while for patients in whom the patellectomy was performed secondarily the score was 63.8 points (range 39-77). The evaluated ROM was 113.6 degrees for all patients; in the primary group ROM was 122.5 degrees (range 65-145 degrees ), and in the secondary group it was 103 degrees (range 85-145 degrees ). The difference was not statistically significant for either parameter.

CONCLUSION

Primary reconstruction of the patella is recommended in multifragmentary fractures; if the outcome is poor, however, patellectomy should be considered early.

Die operative Versorgung suprakondyl�rer Femurfrakturen bei liegender Knieendoprothese?"less invasive stabilization system" (LISS) oder retrograder Marknagel?

Retrograde intramedullary locking nailing as well as the LIS system are propagated as minimally invasive treatment options for distal femoral fractures following total knee arthroplasty. In a retrospective study, we reviewed the clinical results after operative treatment of 18 periprosthetic supracondylar femoral fractures. The fracture was stabilized with the less invasive stabilization system (LISS) in nine patients (average age: 80.3 years) and with a retrograde intramedullary locking nail in the remaining nine patients (average age: 76.8 years). The mean follow-up was 18.2 months (6-35 months). We did not find significant differences concerning the operation time (nailing 99.8 min vs 102.3 min with the LISS) or the length of stay in the hospital (nailing 10.6 days vs 12.7 days with the LISS). In one patient of the nailing group we found a valgus malalignment of 18 degrees. Seven patients in each group were satisfied with the clinical results. In one patient of the LISS group a revision due to an infection was necessary. In one patient of the nailing group a reosteosynthesis had to be performed. To sum up, both systems are useful tools in the treatment of dislocated periprosthetic fractures and both systems are not without any problems. However, under special consideration of the complications we found in our study, the LISS seems to be a better alternative in osteoporotic bone with a small distal fragment. The choice of the optimal implant should therefore depend on the type of fracture and knee arthroplasty, the type of bone, and the experience of the surgeon.

[Importance of the cross-sectional area of the spinal canal in thoracolumbar and lumbar fractures. Is there any correlation between the degree of stenosis and neurological deficit?]

A relationship between traumatic spinal canal stenosis and the degree of neurological deficit is known for the cervical spine. However, this has not been proven for the thoracolumbar and lumbar spine. During a period of 4 years, from 1996 to 1999, 1168 patients with a spinal injury were treated at our department, 473 of these by operation. Thirty-five were examined in a separate group. They showed a single fracture of the thoracolumbar and lumbar spine with stenosis of the spinal canal. All fractures were single burst fractures after blunt trauma. All patients were conscious and fully oriented at the time of admission and a thorough neurological examination could be performed. The fractures were diagnosed by conventional X-ray in two views and computed tomography (CT). Using the transverse CT scans in horizontal view, the sagittal diameter was measured and the degree of stenosis calculated in percent at the level of the fracture and one below and above. The group included 25 male and 10 female patients, with a mean age of 38 years (range: 17-61 years). Of the 35 patients, 19 (54.3%) showed neurological deficits after spinal cord injury,and 16 (45.7%) were without any neurological complications at the time of first admission to the hospital. There was no correlation between the extent of spinal canal stenosis and the degree of the neurological deficit. One patient with stenosis of 20% suffered from neurological dysfunction, others with stenosis up to 80% were without spinal cord injury. The average stenosis of the spinal canal was 49.6% in cases with cord injury and 46.3% in patients without neurological dysfunction. No correlation and no predisposing anatomical structures could be found between stenosis and neurological deficit.

Die postoperative Kontroll-CT nach Acetabulumfraktur

Fractures of the acetabulum are severe injuries of the hip joint. Exact preoperative management is necessary to make possible an anatomical reconstruction. Postoperative quality control is done best with computed tomography. Is the higher radiation exposure caused by this routine examination justified?During the 5 years from 1995 to 1999, a total of 154 patients with fractures of the acetabulum were examined postoperatively at our clinic using CT to control reconstruction, implant position and the remaining free fragments in the joint. Thirteen of these patients (8.4%) had to be re-operated after postoperative CT control. The causes of the re-operation were four cases of an intra-articular implant position, three of free fragments remaining in the joint, and in 6 patients showed inadequate reconstruction. The mean radiation exposure was 25 mGy per patient. The low mean age of the patients and the long lasting consequences of a probably unrecognised complication, justify routine, postoperative CT control, even though the radiation exposure is about 10 mGy higher than the conventional radiological diagnosis. The use of CT diagnosis as a routine postoperative measure is an appropriate control procedure that allows an objective assessment of the quality of the result for the patient as well as for the surgeon.

Arthrodesis of the shoulder after septic arthritis

We analysed the long-term results of arthrodesis of the shoulder after infection in 15 patients. At the time of operation, 14 cultures were positive for Staphylococcus aureus. The mean follow-up was 8.3 years (3 to 14) and 90% of the patients were satisfied with the outcome. There were complications in five patients (33%); in three there was nonunion with loosening of the implant. One patient had a sound bony union but with a persistent sinus six years after arthrodesis and another had a sinus which healed after the metal was removed. Four of these five patients (80%) were heavy smokers (> 20 cigarettes/day). Cancellous bone grafting did not affect the incidence of complications. The mean age of the patients with complications was 58.6 v 48.6 years for those without (p = 0.2808 ; not significant). Those with complications had had more previous operations (6.4 v 2.5, p < 0.05). Antibiotics, as determined by the bacteriological cultures, were administered for six weeks.

The complication rate was higher in patients with active sepsis but the younger the patient and the fewer number of previous operations (< 50 years, < four previous operations), the better was the outcome. Considering the rate of complications, we recommend early surgery in these patients.

Arthrodesis of the shoulder after septic arthritis. Long-term results

We analysed the long-term results of arthrodesis of the shoulder after infection in 15 patients. At the time of operation, 14 cultures were positive for Staphylococcus aureus. The mean follow-up was 8.3 years (3 to 14) and 90% of the patients were satisfied with the outcome. There were complications in five patients (33%); in three there was nonunion with loosening of the implant. One patient had a sound bony union but with a persistent sinus six years after arthrodesis and another had a sinus which healed after the metal was removed. Four of these five patients (80%) were heavy smokers (> 20 cigarettes/day). Cancellous bone grafting did not affect the incidence of complications. The mean age of the patients with complications was 58.6 v 48.6 years for those without (p = 0.2808; not significant). Those with complications had had more previous operations (6.4 v 2.5, p < 0.05). Antibiotics, as determined by the bacteriological cultures, were administered for six weeks. The complication rate was higher in patients with active sepsis but the younger the patient and the fewer number of previous operations (< 50 years, < four previous operations), the better was the outcome. Considering the rate of complications, we recommend early surgery in these patients.

10-Jahres-Ergebnisse knochenmarkstimulierender Therapie der Osteochondrosis dissecans tali

The optimal operative therapy for the treatment of osteochondritis dissecans tali is still controversial. Beside bone marrow-stimulating techniques like abrasion arthroplasty, drilling and microfracturing, new techniques like autologous osteochondral transplantation and autologous chondrocyte transplantation are increasingly used. This study reviewed the clinical, radiological and subjective long-term outcome of bone marrow-stimulating therapy for 45 ankles with an osteochondritis dissecans tali stage 3 or 4 according to the classification by Berndt and Harty. All ankles were treated by the removal of the dissecate and abrasion of the subchondral bone. In 67%, an additional antegrade drilling of the defect was performed. The average maximum size of the lesion was 1.1 cm. At follow-up examination, 10.4 years (7.1-13.5 years) postoperatively, the average AOFAS-score was 91 points (66-100 points). Using the score of Mazur, the outcome of 28 ankles (62%) was rated excellent, 12 ankles (27%) were rated good and five ankles (11%) fair or poor. Progressive osteoarthritic changes, according to the classification of van Dijk, were seen in seven ankles (16%). Reoperations were necessary in eight cases (18%). Obesity, age older than 40 years and preoperative osteoarthritic changes had a significant negative impact on the clinical outcome. Bone marrow stimulating therapy is an inexpensive, low invasive therapy and a good therapeutic option at least for small Berndt/Harty stage 3 and 4 ODT lesions. Autologous chondrocyte transplantation and osteochondral autografts yield encouraging 2- and 4-year results, but still have to prove their superiority in long-term follow-up studies.

Burst fracture of the fifth lumbar vertebra: results of posterior internal fixation and transpedicular bone grafting

Burst fractures of the fifth lumbar vertebra are rare, and there are only a few reports on this subject, which is characterised by its unique anatomical and biomechanical features. This retrospective analysis reports on ten patients whose fractures of L5 were stabilised with a short internal fixator in combination with a posterior fusion as well as transpedicular bone grafting. The average follow-up period was 22 months. Radiometric data were surveyed and compared to the functional results. The height of the fractured vertebra remained nearly unchanged throughout the course. Loss of lordosis of 4 degrees in the upper disc space and 4 degrees in the lower disc space were observed postoperatively. At the time of follow-up, the values of segmental lumbar lordosis were significantly below the preoperative level. The narrowing of the neural canal was reduced from 57% to 28% with the surgical intervention. However, there was no correlation between the functional and the radiological outcome. Neurological deficits were documented in two patients, which declined during the course. There were no severe postoperative complications. The results of the present study demonstrate that the described surgical procedure in fractures of the fifth lumbar vertebra does not promote an anatomic restoration of the fractured vertebra, nor of the segmental lordosis. However, the clinical results do not correlate with the radiological outcome. Nonoperative treatment with early mobilisation without external support seems to be the treatment of choice.

[Coracoid pseudarthrosis caused by anterior shoulder dislocation with concomitant coracoid fracture]

Fractures of the coracoid process are rare and represent only 2-5% of all fractures of the scapula. The most frequent cause of a coracoid fracture is direct trauma, but indirect trauma may also lead to a fracture of this kind. Avulsion injuries as part of an acromioclavicular dislocation are the most frequent forms of trauma. For the rare cases of an anterior shoulder dislocation with concomitant coracoid fracture, two different mechanism are discussed. One cause of the coracoid fracture could be direct impact of the dislocated head of the humerus on the coracoid process, another may be the occurrence of a sudden strong pull of the muscles inserting at the coracoid process during shoulder dislocation.In the majority of cases, conservative treatment with six weeks of immobilization is appropriate. If a pseudarthrosis occurs and there is persistent pain, we recommend the operative fixation of the distal coracoid fragment by insertion of cancellous bone graft taken from the iliac crest and stabilization with a cannulated AO titanium small fragment screw and PDS cord.

Midshaft fractures of the clavicle with a shortening of more than 2 cm predispose to nonunion

Up to 15% of all fractures involve the clavicle. Nonunion of the clavicle is a rare complication after conservative treatment. It mainly presents as pain at the fracture site and a limited range of motion of the shoulder. The purpose of this study is to define a certain type of fracture of the clavicle that is predisposed to malunion and therefore should be treated surgically after failure of conservative treatment. Thirty-nine patients with delayed or malunion of the clavicle were analyzed. There were 13 women and 26 men. The average age of the male patients was 36.4 years (range 20-59 years) and of the female patients, 43.6 years (range 18-55 years). The mean follow-up period was 2.3 years (range 6 months to 4.2 years). All of them were treated surgically. There were 33 Allman I fractures and 6 Allman II fractures. Of the Allman I fractures, 30 (91%) were shortened by at least 2 cm. Allman I fractures were treated using a reconstruction plate or a dynamic compression plate in combination with bone grafting. The time of operation after fracture ranged from 6 weeks to 8.5 years (average 9.8 months). Pain at the fracture site was the leading symptom in all patients. At 6 months after the operation, 38 patients were free of pain with an unlimited range of motion of the shoulder. One patient (2.6%) complained of a slight weakness on the operated site. One fracture failed to unite (2.6%) and had to be replated. There were no refractures, infections, vessel or nerve lesions. To conclude, in Allman I fractures with a shortening of more than 2 cm, we recommend operative treatment in symptomatic patients if there are no signs of callus formation after 6 weeks.

[Supracondylar femoral fractures in knee endoprostheses. Stabilizing with retrograde interlocking nail]

The treatment of supracondylar fractures of the femur in total knee arthroplasty is still challenging, and a variety of methods has been recommended. In a retrospective analysis, we reviewed six patients (average age: 70.5 years) with this type of fracture that had been stabilized with a retrograde intramedullary locking nail [Green-Seligson-Henry (GSH) nail]. The fracture had occurred 34.5 months after implantation of total knee arthroplasty. The average time of the operation was 97.16 min. There were no intra- or postoperative complications. All patients could be followed up at 17.3 months on average. Fracture healing was uneventful in all six cases. The postoperative range of motion was similar to the prefracture level in five patients. One patient demonstrated a loss of extension (10 degrees) associated with a valgus malalignment of 10 degrees. According to our experience, retrograde intramedullary nailing of supracondylar fractures in total knee arthroplasty is a promising alternative, which allows closed reduction and preservation of the soft tissue envelope. Immediate mobilization with partial weight bearing is possible, and the rate of complications is low.

[Complications in the use of the halo fixator]

50 patients out of a total of 88 who underwent treatment using a halo-fixateur between 1987 and 1997 were available for a follow-up interview reviewing local complications and quality of life. Marginal discomfort was observed in 54% of patients, moderate complaints/transitory pain in 30%, prolonged and severe discomfort and pain in 16%. 62% of patients took no analgetics, 22% infrequently, and 16% continuously throughout treatment. In pin-tract infection local treatment was successful in 6 patients, in 3 patients the screws needed to be relocated. Complaints of dysphagia due to extended forced lordosis of the cervical spine could be corrected by adjusting the position of the halo ring in 3 out of 8 patients. 3 patients developed pressure sores which could be managed without surgical intervention. Proper fixation and placement of the pin-tracts are crucial in the application of the halo fixateur if complications are to be avoided. Superficial infections must be treated locally. If the infection persists immediate pin relocation and systemic antibiotic therapy have to be initiated.

[Acute pseudo-obstruction of the colon as complication of hip surgery]

Pseudo-obstruction of the colon is characterized by a massive colonic dilatation without mechanical obstruction. It is rarely after hip surgery, however, untreated it may be complicated by a life threatening perforation of the colon. In a retrospective analysis we reviewed 11 patients (4 women, 7 men, mean age 75.2 years, range 67 to 86 years) with pseudo-obstruction of the colon after hip surgery in the years 1995 to 1998. In relation to all patients aged 65 years and older who underwent surgery of the hip, the prevalence was 1.06%. The leading clinical symptom was abdominal distension. On plain x-rays, dilatation of the colon measured 13.3 cm on average (9-16 cm). In two patients (18%) adequate application of drugs stimulating the gastro-intestinal motility was sufficient, whereas in 8 patients (73%) colonoscopic decompression had to be performed. In three of these, the procedure failed and because of persistent symptoms a cecostomy was performed. One patient underwent immediate laparotomy because of peritonitis. 2 patients (18%) died because of a complicated course. Non operative treatment should not exceed 24 hours, endoscopic decompression and tube placement is considered as the treatment of choice. In cases of failure of these procedures, perforation of the colon and/or peritonism, urgent laparotomy with open decompression by a cecostomy is essential.

[Intrathoracic displacement of the transverse colon as a late complication after abdominal knife stab wound. A case report]

The treatment of stab wounds of the abdomen is discussed controversely. The management of these wounds depends on a high degree on the clinical situation of the patient. Repeated physical examination, peritoneal lavage and laparotomy are recommended. The identification of an isolated diaphragmatic injury is worrisome because its subtle clinical presentation is often not alleviated by adjunctive tests. Delayed recognition of an incarcerated diaphragmatic hernia has a high mortality rate. We report about an 23 year old African male, who was injured by an intraabdominal stab wound. Initially he did not have any clinical problems, but after 6 months he was admitted to the hospital due to severe pulmonary complications. A diaphragmatic hernia with dislocation of the transverse colon into the left thorax was identified on x-rays. A thoracotomy as well as a laparotomy were performed to restore the anatomic conditions and to dose the hernia. After two weeks, the patient could leave the hospital without pulmonary complications. Under consideration of the literature we recommend exploratory laparotomy for stab wounds that penetrate the left side of the chest below the fourth intercostal space anteriorly, the sixth intercostal space laterally and the tip of the scapula posteriorly. The high mortality rate after a delayed recognition appears to justify an early operative approach.

Traumatic spondylolisthesis of the axis: treatment rationale based on the stability of the different fracture types

Thirty-nine consecutive patients, 22 male and 17 female with an average age of 37.6 years, with traumatic spondylolisthesis of the axis were reviewed. The cause of injury in 75% of the patients was a road traffic accident. The fractures were classified according to Effendi et al., the type II fractures were further divided into three subgroups: flexion, extension and listhesis injuries. There were 10 type I (25.7%) and 29 type II fractures (74.4%); of these, 12 (30.8%) were classified as flexion-type, 2 (5.1%) as extension-type and 15 (38.5%) as listhesis-type. We did not identify any case of type III injury. Overall, 43.5% of the patients had sustained a significant head or chest trauma, with the highest incidence for type II listhesis injuries. Significant neurological deficits occurred in four patients (10.3%); in all four,the fracture was classified as a type II listhesis. All ten type I injuries were successfully treated with a cervical orthosis. Ten of the 12 type II flexion injuries demonstrated significant angulation. Two were treated with internal stabilisation, in seven with a halo device and one with a minerva plaster of Paris (PoP). Healing was uneventful in all ten patients. For the remaining two stable type II flexion injuries, application of a hard collar was adequate, as was the case for the two stable type II extension injuries. Six of the 15 type II spondylolisthesis injuries underwent primary internal stabilisation, and healing was uneventful in all cases. In four (44.4%) of the nine injuries that were primarily treated with a halo device/minerva PoP, secondary operative stabilisation had to be performed. The classification of Effendi et al. provides a complete description of the different fractures. However, further distinction of the type II injuries regarding their stability is mandatory. Type II spondylolisthesis injuries are unstable, with a high number of associated injuries, a great potential for neurological compromise and significant complications associated with non-operative treatment. The majority of type II extension and type II flexion injuries can be successfully treated with nonrigid external immobilisation.

[Anterior screw fixation for odontoid fractures]

The results of anterior screw fixation of odontoid fractures in 28 patients are presented. There were 27 type II- and 1 type III-injuries. Non-union with persistent instability had to be notified in one patient (3.6 %), secondary posterior C1/2 fusion had to be performed. Incorrect positioning of the screws in the odontoid with penetration of the postero-lateral cortex occurred in 3 patients (10.7 %). Malpositioning of the odontoid after screw fixation was documented in 5 cases (17.9 %). Cardiopulmonary complications had to be treated in 5 patients (17.9 %), 4 patients (14.3 %) died in the postoperative period. 17 patients could be followed up. Only 3 patients (17.8 %) were free of symptoms. A significant limitation in ROM of axial rotation was seen in 44 % of the patients. With anterior screw fixation of the odontoid high fusion rates can be achieved, however the procedure is technically demanding. Regarding the functional outcome, there is no significant difference to other established treatment methods.

Management of odontoid fractures in the elderly

Odontoid fractures are frequent in patients over 70 years of age, and in patients over 80 years of age they form the majority of spinal fractures. In a retrospective analysis of 23 geriatric (> 70 years) patients with a fracture of the odontoid, we compared some of the clinical features to a contemporary series of patients younger than 70 years of age. Whereas in the younger patients high-energy trauma accounted for the majority of the fractures, low-energy falls were the underlying cause in 90% of the odontoid fractures in the elderly. In contrast to the younger age group, in elderly patients predominantly type II fractures (95%) were identified. Anterior and posterior displacement were recorded with equal frequency on the first postinjury radiograph in the younger age group, whereas in geriatric patients displacement was mainly posterior. The number of associated injuries was significantly higher in younger patients. There was no difference in the occurrence of neurological deficits (13%) between the two age groups, and neurological compromise was mainly related to posterior dislocation of the odontoid in both groups. The overall complication rate was significantly higher in elderly patients (52.2% vs 32.7%), with an associated in-hospital mortality of 34.8%. Loss of reduction and non-union after non-operative treatment, a complicated postoperative course and complications due to associated injuries accounted primarily for this high complication rate. Elderly patients with a fracture of the odontoid are a high-risk group with a high morbidity and mortality rate. An aggressive diagnostic approach to detect unstable fractures and application of a halo device or early primary internal stabilisation of these fractures is recommended.

Anticoagulant properties, clinical efficacy and safety of efegatran, a direct thrombin inhibitor, in patients with unstable angina

AIMS

Thrombin plays a key role in the clinical syndrome of unstable angina. We investigated the safety and efficacy of five dose levels of efegatran sulphate, a direct thrombin inhibitor, compared to heparin in patients with unstable angina.

METHODS

Four hundred and thirty-two patients with unstable angina were enrolled. Five dose levels of efegatran were studied sequentially, ranging from 0.105 mg. kg(-1). h(-1)to 1.2 mg. kg(-1). h(-1)over 48 h. Safety was assessed clinically, with reference to bleeding and by measuring clinical laboratory parameters. Efficacy was assessed by the number of patients experiencing any episode of recurrent ischaemia as measured by computer-assisted continuous ECG ischaemia monitoring. Clinical end-points were: episodes of recurrent angina, myocardial infarction, coronary intervention (PTCA or CABG), and death.

RESULTS

Efegatran demonstrated dose dependent ex-vivo anticoagulant activity with the highest dose level of 1.2 mg. kg(-1). h(-1)resulting in steady state mean activated partial thromboplastin time values of approximately three times baseline. Thrombin time was also increased. Neither of the efegatran doses studied were able to suppress myocardial ischaemia during continuous ECG ischaemia monitoring to a greater extent than that seen with heparin. There were no statistically significant differences in clinical outcome or major bleeding between the efegatran and heparin groups. Minor bleeding and thrombophlebitis occurred more frequently in the efegatran treated patients.

CONCLUSION

Administration of efegatran sulphate at levels of at least 0.63 mg. kg(-1). h(-1)provided an anti-thrombotic effect which is at least comparable to an activated partial thromboplastin time adjusted heparin infusion. There was no excess of major bleeding. The level of thrombin inhibition by efegatran, as measured by activated partial thromboplastin time, appeared to be more stable than with heparin. Thus, like other thrombin inhibitors, efegatran sulphate is easier to administer than heparin. However, no clinical benefits of efegatran over heparin were apparent.

Ipsilateral fractures of the pelvis and the femur--floating hip? A retrospective analysis of 42 cases

A consecutive series of 40 patients, who sustained 42 ipsilateral pelvic and femoral fractures, is reported. There were eight (26.6%) traumatic neurological deficits and three open femoral fractures. Two multiply injured patients died in the postraumatic period because of the severity of their injuries. No associated vascular injuries could be identified. All but two fractures of the femur, 8 of the 15 fractures of the pelvic ring and 17 of the 30 fractures of the acetabulum were treated by internal fixation. In 26 patients internal fixation was performed on both fracture components (in 17 patients this was done under the same period of anaesthesia). Postoperatively, a deep venous thrombosis in three patients, one deep wound infection and five (18.5%) iatrogenic neurological deficits had to be notified. In this series we could not identify any specific associated injuries and complications as known for the floating knee or the floating elbow. The term floating hip is inprecise and misleading, and its use is not recommended. The treatment of this fracture-combination follows the guidelines established for the individual lesions.

Surgical excision of heterotopic bone after hip surgery followed by oral indomethacin application: is there a clinical benefit for the patient?

The clinical effect of surgical excision of heterotopic bone after hip surgery in combination with an oral indomethacin application was analysed in 21 patients in a retrospective study. Indomethacin (3 x 50 mg) was administered after the first postoperative day for a period of 6 weeks. To avoid gastrointestinal side-effects, a mucoprotectivum (sucralfat, 3 x 1 g) was also applied. One year after surgery, 19 patients (90.4%) had excellent relief of pain, the average improvement of flexion was 40 degrees, of abduction 13 degrees, of internal rotation 8 degrees and of external rotation 14 degrees. Only one patient (4.8%) suffered a recurrence of heterotopic bone formation, and in one patient (4.8%) we observed gastrointestinal side-effects. Thus, we recommend surgical excision of heterotopic bone followed by oral indomethacin therapy as a convenient and reliable strategy to prevent new heterotopic bone formation after hip surgery.

[Spinal contusion after trauma to the cervical spine--relevance of the sagittal diameter of the spinal canal]

PURPOSE

The purpose of this study was to analyze the relationship between spinal stenosis and cervical myelopathy. Furthermore it was to investigate whether there is a correlation between spinal stenosis and progression of neurologic symptoms?

PATIENTS AND METHODS

Using the Pavlov ratio method, we compared 14 patients with a contusio spinalis with 14 patients who suffered from a distortion of the cervical spine. This ratio is calculated by the sagittal diameter of the spinal canal with the anteroposterior width of the vertebral body.

RESULTS

In eight patients with a contusio spinalis, there was a spinal stenosis, while there was none in the distortion group. The remaining patients with a contusio had severe degenerative changes in routine roentgenograms of the cervical spine. The Pavlov ratio was statistically significant reduced in the contusio group. After 8.5 days there was a complete regression of neurologic symptoms, whereas in 4 patients there was no full recovery.

CONCLUSION

To conclude we demonstrated that a spinal stenosis promotes a contusio spinalis but there is no evidence that the Pavlov ratio allows statements concerning the progression of the injury.

[Surgical management of posttraumatic mal-alignments and arthroses in the ankle]

Joint incongruency, malalignement as well as degenerative changes of the ankle joint may result in disabling pain with a significant decrease in function and mobility. The clinical symptoms may affect all aspects of life. Primary osteoarthritis of the ankle joint is uncommon, and posttraumatic conditions with significant changes in joint mechanics are usually the primary source of joint degeneration with the resultant clinical symptoms. Apart from pain relief and restoration of joint mobility, prevention of joint degeneration or progression of arthrosis should be the main goal in treating such conditions. Arthrodesis of the ankle still is the method of choice for severe osteoarthritis of the ankle, however several surgical treatment options are available to deal with mild to moderate joint degeneration. Restoration of the anatomy and joint alignement in posttraumatic deformities as well as ligament reconstruction in chronic instability are measurements to prevent development or progression of osteoarthritis. Joint debridement is useful in primary anterior joint pathology, in advanced osteoarthritis at least temporary pain relief can be achieved. In severe osteoarthritis arthrodesis of the ankle is the method of choice for long-term pain relief and restoration of mobility.

[Prostheses of the head of the radius. What outcome can be expected?]

We report our results after primary implantation of 30 radial head prostheses in a retrospective study from 1978 to 1996. If there was intraoperatively a remaining instability of the elbow after resection of the radial head, we implanted a prosthesis. The average age of our patients was 40.7 years. The results were evaluated concerning the recommendations of Radin and Riseborough. In 22 patients (73%) we found good to satisfactory results, in 8 patients (27%), there was a free range of motion. Heterotopic ossifications with a remarkable decrease in the range of motion were discovered in 3 patients (10%). The implant had to be removed in three (10%) patients (2 incorrect implantations, one broken prosthesis). To conclude, the primary implantation of a radial head prosthesis after a strict indication improves the clinical benefit for the patient. A correct surgical technique avoids unnecessary complications.

[Accident-induced pseudarthroses of the dens axis. Etiology, follow-up and therapy]

In a retrospective analysis the significance of internal fixation of unstable and symptomatic non-union of the odontoid was evaluated. In all but one cases a type II fracture of the odontoid was the underlying cause for the pseudarthrosis. The time interval between trauma and definitive diagnosis varied between 6 months and 30 years. All patients asked for medical advice because of acute neck pain; in three cases additional neurological deficits were notified. In all but one case the pseudarthrosis was classified as unstable on flexion-/extension views. The occurrence of neurological deficits showed a positive correlation with the amount of dislocation of the pseudarthrotic odontoid. Nine out of 10 patients underwent internal stabilisation of the non-union. Reoperation because of persistent instability/failure of stabilisation had to be performed in two cases (22.2%). At follow-up all 9 patients were pain-free. The neurological deficits in two patients had improved significantly. According to our experience internal stabilisation in unstable non-union of the odontoid is recommended to achieve significant reduction of the pain level. Also improvement of the neurological deficits can be expected depending on the duration of the symptoms.

[Subdural abscess as a complication of halo fixator]

Complications associated with the application of a halo device are not infrequent; however, osteomyelitis of the skull with a consecutive subdural abscess is a rare but severe complication. We present the case of a patient with a subdural abscess as a result of a local pin-track infection of the halo device, in whom pathological behavior was the primary clinical finding. The possible complications associated with the halo device are discussed with emphasis on associated head injuries and preexisting neurological diseases, as well as indications for the halo, clinical symptoms of pin-track infections, necessary diagnostic measurements and the appropriate treatment.

The motorcyclist: easy rider or easy victim? An analysis of motorcycle accidents in Germany

This report reviews the findings from 86 motorcycle accidents during a 1-year period at the Trauma Center "Bergmannsheil" in Bochum, Germany. A study of the case histories supplemented by telephone conversations yielded the following results: 90.7% of the patients were men, and the average age was 28.8 years; most of the accidents occurred in the 25- to 30-year-old age group (27.9%). Motorcycle accidents happened mostly during recreational rides on weekends in the summertime. Although there was a high rate of helmet use (98.8%), the head region was affected in 12 victims. Two patients died because of their severe head injuries (2.3%). Lower extremity injuries (46%), especially open tibia fractures (19.7%), were among the most common injuries sustained. Fractures of the distal radius constituted the largest portion of upper extremity injuries (18.8%). The average stay in our hospital was 35.4 days; 23.4% of the patients had to change jobs after the accident. Fifty percent of the crashes happened with motorcycles between 500 and 750 cc stroke volume. Although 34.5% possessed their driver's licenses for more than 8 years, they had not had much experience handling a motorbike. These results underline the fact that motorcycle accidents are sustained by young men in their working prime; as a result, these accidents pose a tremendous burden to individuals and society and every attempt should be made to offer highly qualified surgical and trauma care to minimize the damage to the motorbiker. A plea is made for more prevention measures like driver education, better road conditions, or legislative changes to prevent motorcycle crashes. The wearing of a helmet is strongly advocated.

[Os odontoideum. Etiology, clinical aspects, therapy]

The etiology of os odontoideum is still controversial. In most patients, it is found by accident because of neurological symptoms and/or painful range of motion of the cervical spine. Upon recognition of the os odontoideum, it is unknown whether or not immediate surgery is beneficial. This is in contrast to an "unstable" os odontoideum, which could result in atlantoaxial instability or compression of the myelon. In this study, we present the results of our treatment of four patients with an unstable os odontoideum. In all four cases, a C1-2 fusion was performed (3 x Magerl/Seemann, 1 GallieBrooks). Postoperatively, we found a complete regression of neurological symptoms in three patients and one was significantly improved. The range of motion of the cervical spine was free of pain in all patients. As a result, we strongly support immediate surgical treatment of an unstable os odontoideum in order to prevent severe and life-threatening neurological complications.

Comparison of usefulness of computer assisted continuous 48-h 3-lead with 12-lead ECG ischaemia monitoring for detection and quantitation of ischaemia in patients with unstable angina

AIMS

The selection of ECG leads used for ST monitoring may influence detection and quantitation of ischaemia.

METHODS

We compared on-line continuous 48-h 12-lead against 3-lead ST monitoring in 130 unstable angina patients (Mortara. ELI-100). Onset and offset of ST episodes were defined by the lead with the first > or = 100 microV ST change relative to baseline and the lead with the latest return to baseline ST level, respectively. ST episodes were calculated for 12 leads and 3 leads (V2, V5, III) separately.

RESULTS

ST episodes were detected in 88 patients (77%) by 12-lead and in 71 patients (62%) by 3-lead ST monitoring (P < 0.02). The median number (25.75%) of episodes/patient was 1 (0.3) for 3-lead and 2 (1.6) for 12-lead (P < 0.0001). The total duration of ischaemia detected during 12-lead far exceeded 3-lead monitoring: 12.3 (1, 58.2) and 1.7 (0, 23.3) min respectively (P < 0.0001). The probability of recurrent ischaemia declined most during the first 24 h of monitoring. After a period without ST changes of 1, 12, 24 and 36 h, the probabilities of recurrent ischaemia were 63, 31, 14 and 9%, respectively.

CONCLUSIONS

Continuous 12-lead ST monitoring increases detection rate and duration of ST episodes compared to 3-lead ST monitoring. The use of continuous 12-lead ECG monitoring devices on emergency wards and coronary care units is recommended.

[Missed diagnosis in delayed recognition of bilateral simultaneous rupture of the quadriceps tendons]

In this article we report a very rare case of simultaneous and bilateral rupture of the quadriceps tendon in a 38-year-old patient. The initial diagnosis was "herniated vertebral disk". Although there was an extensive neurological and psychiatric examination in combination with several operations, it took almost 3 months until the real reason was found. In this case report we describe our postoperative treatment of early mobilization and compare it with other therapies.

Activation of the fibrinolytic system during intracoronary streptokinase administration

Serial biochemical studies were performed in 12 patients treated with intracoronary streptokinase infusion for acute myocardial infarction, in order to study the method of activation of the fibrinolytic system during local administration of a relatively low dose of this drug and to determine correlations between systemic effects and reperfusion. Plasma samples were obtained before and every 15 minutes during the infusion of streptokinase and after completion of the therapy. Streptokinase dosage in this study was 211,000 +/- 88,000 IU (+/- SD). The average time from the onset of symptoms to the start of infusion was 2 hours 50 minutes (range 1 hour 10 minutes to 3 hours 30 minutes). Reperfusion occurred in six patients and temporary recanalization in three; in three patients no recanalization was achieved. Fibrinolytic assays of pretreatment plasma samples revealed elevated levels of plasminogen activators, presumably caused by the release of tissue-type plasminogen activator after a condition of stress. Plasminogen concentrations decreased from 94 +/- 17% to 44 +/- 30%. Alpha 2-antiplasmin fell from 84 +/- 27% to 12 +/- 19%; in seven patients no plasmin inhibitor activity was measurable at the completion of the infusion. Free plasmin occurred in samples only when this inhibitor had disappeared. This resulted in a lytic state leading to degradation of fibrinogen, the levels of which fell from 2.9 +/- 0.7% to 1.5 +/- 1.1%. Fibrinogen degradation products, measured in plasma with monoclonal antibodies, increased exponentially during streptokinase infusion in at least four patients.(ABSTRACT TRUNCATED AT 250 WORDS)