A hydrodynamically optimized nano-electrospray ionization source and vacuum interface.

The coupling of atmospheric pressure ionization (API) sources like electrospray ionization (ESI) to vacuum based applications like mass spectrometry (MS) or ion beam deposition (IBD) is done by differential pumping, starting with a capillary or pinhole inlet. Because of its low ion transfer efficiency the inlet represents a major bottleneck for these applications. Here we present a nano-ESI vacuum interface optimized to exploit the hydrodynamic drag of the background gas for collimation and the reduction of space charge repulsion. Up to a space charge limit of 40 nA we observe 100% current transmission through a capillary with an inlet and show by MS and IBD experiments that the transmitted ion beams are well defined and free of additional contamination compared to a conventional interface. Based on computational fluid dynamics modelling and ion transport simulations, we show how the specific shape enhances the collimation of the ion cloud. Mass selected ion currents in the nanoampere range available further downstream in high vacuum open many perspectives for the efficient use of electrospray ion beam deposition (ES-IBD) as a surface coating method.

Glucocorticosteroid-induced osteoporosis in adult primiparous Göttingen miniature pigs: effects on bone mineral and mineral metabolism.

Information on the pathophysiology of glucocorticoid-induced osteoporosis (GIO) is limited, since its clinical picture often reflects a combined effect of glucocorticoids (GC) and the treated systemic disease (i.e., inflammation and immobility). In 50 healthy adult (30-mo-old) primiparous Göttingen minipigs, we studied the short-term (8 mo, n = 30) and long-term (15 mo, n = 10) effect of GC on bone and mineral metabolism longitudinally and cross-sectionally compared with a control group (n = 10). All animals on GC treatment received prednisolone orally at a dose of 1.0 mg x kg body wt(-1) x day(-1) for 8 wk and thereafter at 0.5 mg/kg body wt(-1) x day(-1). In the short term, GC reduced bone mineral density (BMD) at the lumbar spine by -47.5 +/- 5.1 mg/cm(3) from baseline (P < 0.001), which was greater (P < 0.05) than the loss [not significant (NS)] in the control group of -11.8 +/- 12.6 mg/cm(3). Calcium absorption decreased from baseline by -2,488 +/- 688 mg/7 days (P < 0.001) compared with -1,380 +/- 1,297 mg/7 days (NS) in the control group. Plasma bone alkaline phosphatase (BAP) decreased from baseline by -17.8 +/- 2.2 U/l (P < 0.000), which was significantly different (P < 0.05) from the value of the control group of -1.43 +/- 4.8 U/l. In the long term, the loss of BMD became more pronounced and bone mineral content (BMC), trabecular thickness, mechanical stability, calcium absorption, 25-hydroxyvitamin D(3), 1,25-dihydroxyvitamin D(3), and parathyroid hormone tended to be lower compared with the control group. There was a negative association between the cumulative dose of GC and BMD, which was associated with impaired osteoblastogenesis. In conclusion, the main outcomes after GC treatment are comparable to symptoms of GC-induced osteoporosis in human subjects. Thus the adult Göttingen miniature pig appears to be a valuable animal model for GC-induced osteoporosis.

Comparing ultrasound measurements of neonatal hips using the methods of Graf and Terjesen.

In a prospective study, 232 neonates were examined sonographically using the methods of Graf and Terjesen. In order to determine the reproducibility of the methods, 50 hips were evaluated by two skilled examiners. In an inter-observer study, five physicians and five medical students evaluated 24 images, which were evaluated on ten occasions at two-weekly intervals by one of the authors. Statistical evaluation used the Bland-Altman approach. The neonates (110 females, 122 males) were less than four days old. The mean alpha angle was 62.4 degrees and mean femoral head cover was 55.4%. According to Graf's method, 1.3% of hips were pathological, compared with 4.1% according to Terjesen. Spearman's correlation coefficient between femoral head cover and alpha angles was 0.552. The Bland-Altman approach shows greater variation for femoral head cover than for alpha, if measured by experienced examiners. The Bland-Altman approach shows almost equal reproducibility for alpha and femoral head cover in the inter-observer test, but better repeatability for alpha in the intra-observer test. The Graf results relate better than Terjesen's to the well-known frequency of 1% to 2% hip dysplasia in the European population. Kappa statistics indicate a fair agreement between the two methods. Inter-observer evaluation shows an equal reproducibility of both methods, whereas intra-observer tests reveal better repeatability with Graf's method.

[Psychogenic Disorders in German soldiers during World War I and II]. / Psychogene Störungen bei deutschen Soldaten des Ersten und Zweiten Weltkrieges -- Eine vergleichende Betrachtung unter psychotraumatologischen Gesichtspunkten.

In the First and Second World War German soldiers frequently suffered from psychogenic disorders. By comparison a change in the prevalences can be noted: in the First World War dissociative disorders dominated the clinical impression ("shell shock"), in the Second World War they could rarely be seen but were replaced by somatoform and psychosomatic diseases. The discussion about numerous reasons for this development has not been completed yet and is still not free from political attitudes. To achieve a more scientific point of view, the perspective of psychotraumatology might be helpful. According to psychotraumatic research, dissociative and somatoform disorders can emerge in a close relation to a Posttraumatic Stress Disorder. The choice of symptoms depends on personality traits of the victim, but also on specific factors that characterise the situation in which the trauma appears. The mixture of pathogenetic and protective influences includes e. g. the possibility of flight- or fight reactions, feelings of trauma-associated guilt and group cohesion in the military unit. These factors can be useful to help explain the change of symptoms between both wars. In addition the analysis of situational conditions in former wars can give hints to actual planning and prophylaxis strategies in modern military psychiatry, that has to adjust to very different military operation fields.

The dimensional accuracy of preparation of femoral cavity in cementless total hip arthroplasty.

OBJECTIVE: To observe the accuracy of femoral preparation and the position of the cementless prosthesis in femoral cavity, and to compare the results between the computer-assisted surgical group (CASPAR) and the conventional group. METHODS: Ten femoral components were implanted either manually or by CASPAR in cadaver femurs. The specimens were cut to 3 mm thick slices. Microradiograms of every slice were sent to a computer for analysis with special software (IDL). The gaps and the medullary cavities between component and bone, the direct bone contact area of the implant surface, the gap width and the percentage of gap and bone contact area were measured in every slice. RESULTS: In the proximal implant coated with HA of the CASPAR group, the average percentage of bone contact reached 93.2% (ranging from 87.6% to 99.7%); the average gap percentage was 2.9% (ranging from 0.3% to 7.8%); the maximum gap width was 0.81 mm and the average gap width was only 0.20 mm. While in the conventional group, the average percentage of bone contact reached 60.1% (ranging from 49.2% to 70.4%); the average gap percentage was 32.8% (ranging from 25.1% to 39.9%); the maximum gap width was 2.97 mm and the average gap width was only 0.77 mm. The average gap around the implant in the CASPAR group was only 9% of that in the manual group; the maximum and average gap widths were only about 26% of those in the manual group. On the other hand, the CASPAR group showed 33% tighter bone contact than the manual group. CONCLUSION: With the use of robotics-assisted system, significant progress can be achieved for femoral preparation in total hip arthroplasty.

Early age of onset in fatal familial insomnia. Two novel cases and review of the literature.

Fatal familial insomnia (FFI) is a prion disease exhibiting the PRNP D178N/129M genotype. Features of this autosomal dominant illness are progressive insomnia, dysautonomia, myoclonus, cognitive decline and motor signs associated with thalamic nerve cell loss and gliosis. In contrast to the new variant of Creutzfeldt-Jakob disease (vCJD) the onset of FFI is in middle to late adulthood. We report two male patients who belong to a large German FFI kindred. They were examined clinically, and postmortem neuropathological examination was carried out in collaboration with the German reference centre for prion disease. Additionally, the prion protein gene (PRNP) was analysed. To identify further patients with disease onset under 30 years of age a comprehensive literature review was carried out. Two male patients presented with typical symptoms of FFI at the age of 23 and 24 years. In their kindred, the age of onset has never before been under 44 years of age. Our literature review identified five additional early onset cases who died at age 21 to 25 years. In all 22 reviewed FFI families the median manifestation age was 49.5 years. Although phenotypic variability of FFI is common, age of onset under 30 years has been considered to be a hallmark of vCJD with a mean manifestation at 27 years of age. Our findings underline that in addition to vCJD, FFI must be considered in cases of young-onset prion disease. This has considerable impact on clinical management and genetic counselling.

Comparable ultrasound measurements of ten anatomical specimens of infant hip joints by the methods of Graf and Terjesen.

PURPOSE: To define which sonographic section planes relative to the acetabular inlet plane will produce analyzable images with the methods of Graf and Terjesen. MATERIAL AND METHODS: Anatomical specimens of infant hip joints were investigated in a water bath using the methods of Graf and Terjesen. Acetabular position was varied in defined increments with respect to the ultrasound beam. The alpha angles and the femoral head coverage (FHC) were measured. RESULTS: To obtain images analyzable by the two methods, the ultrasound beam had to intersect with the acetabular inlet plane at defined angles. The acetabular notch had to be anteriorly rotated from the ultrasound beam plane by at least 20 degrees. Beam entry within a 50 degrees sector posterior to the perpendicular on the inlet plane resulted in analyzable images. The stepwise multiple linear regression analysis showed that alpha angles and FHC were much affected by the coronal-plane transducer tilt. CONCLUSION: The fact that caudal tilts of the transducer are associated with reduced alpha angles and FHC values should be kept in mind in clinical ultrasound investigations. It is recommended that the transducer should be put on the greater trochanter perpendicular to the transverse axis of the body.

Survival analysis of hips treated with flexion osteotomy for femoral head necrosis.

The treatment of osteonecrosis of the femoral head (FHN) is controversial. It mainly occurs in young patients in whom total hip replacement is best avoided because of an increased risk of revision. The objective of this long-term follow-up study was to evaluate the outcome of intertrochanteric flexion osteotomy as a hip joint preserving operation for FHN. Over a 19-year period we carried out 70 intertrochanteric flexion osteotomies for FHN in 64 patients. The mean follow-up was 10.4 years (3.0 to 20.3). The overall mean Harris hip score increased from 51 points preoperatively to 71 points postoperatively. Six patients (9%) developed early postoperative complications. A total of 19 hips (27%) underwent total hip arthroplasty at a mean of 8.7 years after osteotomy. The five-year survival rate was 90%. Survival rates of hips in Ficat stage 2 were higher than those in stages 3 or 4. Hips with a preoperative necrotic angle of <200 degrees had a better survival probability than those with a necrotic angle >200 degrees. Our findings suggest that flexion osteotomy is a safe and effective procedure in Ficat stage 2 and 3 FHN, preferably with a necrotic angle of <200 degrees.

[Long-term results with cement-free total hip prostheses (Zweymuller)]. / Langzeitergebnisse zementfreier Hüftvollprothesen (Zweymüller).

AIM OF THE STUDY: The purpose of the study is the evaluation of subjective, clinical and radiological long-term results of cementless total hip replacements with "Zweymüller" stems and various cups. METHOD: 113 of 165 consecutively implanted "Zweymüller" stems have been examined clinically and radiologically as well as assessed for subjective satisfaction by questionnaire, 26 additional patients were analysed by questionnaire only. Thus, the follow-up rate is 85.5% with a mean follow-up period of 8.9 years (range 5-12.2 years) as far as evaluation of subjective information including data on failures is concerned. The follow-up results were rated by the scores of Merle d'Aubigné and Harris and radiolucent lines on the X-rays were analysed. RESULTS: 96% of the analyzed patients stated subjective satisfaction. 101 hips caused no or only little pain. The average Harris Hip Score rose from 47.1 preoperative to 86.8 postoperative, the functional value of Merle d'Aubigné rose from 4.9 to 10.1 (maximum 12 points). The survival rate of the stems after 10 years is 96%, the complication rate is very low. 81% of the stems showed a proximal radiolucent line. 3 different kinds of cups were used, 79% of the polyethylene cups and 8% of the titanium cups, respectively, were loosened or had been explanted at the time of examination. CONCLUSIONS: During an observation period of 12 years, the implantation of the "Zweymüller" stem has very successful results. The proximal radiolucent lines should nevertheless cause concerns about the predominantly distal anchoring of the stem. The long-term survival of the stems is much better than that of the titanium cups.

[Is a general pharmacologic thromboembolism prophylaxis necessary in ambulatory treatment by plaster cast immobilization in lower limb injuries?]. / Ist eine generelle medikamentöse Thromboembolieprophylaxe bei ambulanter Therapie von Verletzungen der unteren Extremität im immobilisierenden Unterschenkelstützverband notwendig?

Selected patients with minor lower limb injuries and low risk for deep vein thrombosis (DVT), who required cast immobilizing and did not receive medical thrombosis prophylaxis, were included in a prospective study. The decision to give not medical thrombosis prophylaxis depended on an concept of individualised prophylaxis for patients at risk for thromboembolism. From March 1994 to March 1996 in 178 outpatients (118 men, 60 women, mean age 25.8 [16-39] years) a clinical examination and a colour-coded duplex sonography were performed after removal of the cast for detection of DVT of the lower limb. A phlebography was performed when thrombosis was suspected. Two patients developed a one bundle thrombosis of the calf. Clinical appearance of lung embolism was not observed. These results suggest, that low risk patients with minor injuries of the lower limb and plaster cast immobilisation do not need a medical thrombosis prophylaxis.

Sonographic hip screening and early management of developmental dysplasia of the hip.

The reliability of Graf's technique in diagnosing developmental dysplasia of the hip (DDH) is investigated in this report. In a prospective study, 6,548 neonates were examined clinically and sonographically; 470 children were reexamined at least once. Sonographic alpha angles and radiographic acetabular index (AI) angles were followed up and compared. Results were as follows: 84.6% of the hips were mature; 14.3% were physiologically immature; 1.1% were dysplastic. Of the sonographically dysplastic hips, 63% were clinically normal. Neonatal sonographic hip status was affected by family history, breech delivery, birth weight, and gestational age. At follow-up, none of the primarily mature hips had worsened. Of the type IIa hips, 89% matured spontaneously, and 11% needed abduction. The 68 dysplastic hips had matured after a maximum of 80 days' abduction, with normal alpha and AI angles by the end of treatment. At 1 year, the pitch had deteriorated again in six children. Graf's sonographic technique reliably diagnoses infantile DDH. Regular orthopedic checkups are needed to detect secondary deterioration of dysplastic hips.

[Long-term results of tibial head osteotomy]. / Langfristige Ergebnisse nach Tibiakopfosteotomie.

QUESTION: Long term outcome after high tibial osteotomies is essential too for the actual indication of these procedures. Complications and success rate were analysed in our patients in order to find out predictive determinants for the outcome. METHOD: 200 high tibial osteotomies were performed at the Orthopaedic clinic of Kiel University between 1974 and 1983. 148 knees (74%) could be reviewed with an average follow-up period of 10 years. 103 knees were personally examined, 45 cases were investigated by questionnaire. RESULTS: 74% were content with the result of the operation. Deterioration of complaints could be stopped in many cases, although the radiographic changes were not parallel to subjective relief of pain. The survival rate without implantation of knee prostheses was 96% 12 years postoperatively. In 10 cases which had continuous complaints knee arthroplasties were performed one to two years after high tibial osteotomy. 6 knees required additional surgery because of loss of correction. Serious complications did not occur apart from one peroneal nerve palsy and two deep though completely healed infections. CONCLUSION: High tibial osteotomy in a modified procedure according to Coventry thus guarantees long term success with low risk of failure only.

[Follow-up and ultrasound-controlled early treatment of hip dysplasia]. / Verlaufskontrollen und sonographisch gesteuerte Frühbehandlung der Hüftgelenksdysplasie.

PROBLEM: The reliability of ultrasound of the hip is examined by the courses of mature and physiologically immature hips. The results of sonographically controlled therapy of the congenital dysplasia of the hip are investigated. METHOD: 470 children out of a hip-screening program could be controlled at least one more time clinically and by ultrasound. X-rays were taken at the end of treatment in children who were treated by an abduction device. The sonographical and radiological results were compared and grafically presented. RESULTS: None of 570 matured hips deteriorated. 88% of the physiologically immature hips matured spontaneously while 12% got a cast because of unsatisfactory development. 68 pathological hips improved soon under therapy in an abduction device applied a few days after birth; they reached the borderline of 60 degrees at the maximum age of 80 days. X-ray examinations at the end of therapy showed normal acetabular indices in all cases. Six of 22 girls showed deterioration of the acetabular indices in further x-ray controls at the age of one year. CONCLUSION: Even in successful therapy of the congenital dysplasia in the newborn hip x-ray examinations are highly recommended to recognize deteriorations and to initiate another therapy if neccessary.

[[So-called congenital hip dislocation--development of incidence, diagnosis and therapy in the last 7 years]. / Die sogenannte angeborene Hüftgelenkluxation--Entwicklung von Häufigkeit, Diagnose und Therapie in den letzten sieben Jahren.

PROBLEM: How has the Congenital Dislocation of the Hip (CDH) developed in the last 7 years concerning frequency, time of diagnosis and therapy? METHOD: Retrospective analysis of hospital reports, ultrasound- and X-ray images of children treated with CDH in the University Hospital. RESULTS: From 1. 1. 1991 to 31. 12. 1997 21 children with 28 dislocated hips were treated. The number of dislocated hips per anno is less than in a former study. In 17 children the diagnosis was found by ultrasound. The diagnosis was made within the first week of life in 8 children. In 9 dislocated hips, open reduction was necessary; in 7 of these 9 joints, diagnosis was made in the first days of life. CONCLUSIONS: Because of the distinct declination of CDH the "true" congenital dislocations, in which open reductions were often necessary, predominated.

[Patellofemoral contact zones in knee endoprostheses]. / Patellofemorale Kontaktzonen bei Knieendoprothesen.

Failures after total knee arthroplasty often are caused by problems of the patellofemoral articulation. We investigated 10 different femoral components and 12 different patellar implants. The size of the patellofemoral contact areas was evaluated by pressure sensitive films every 10 degrees up to 90 degrees of flexion. The forces of the quadriceps muscle and the patella ligament were measured by force transducers. The compressive forces acting between patella and gliding grove were calculated. The geometry of the components and forces was documented. The retropatellar contact areas are specific for each prosthesis. The patterns of displacement are similar for some groups of prostheses. The absolute size of the contact areas and their size relative total surface of the patellar implant is very small. This induces high local pressure of the polyethylene.

[Comments on the use of the "life-table method" in orthopedics]. / Gedanken zur Anwendung der 'Life-Table-Methode' in der Orthopädie.

In the description of long term results, e.g. of joint replacements, survivorship analysis is used increasingly in orthopaedic surgery. The survivorship analysis is more useful to describe the frequency of failure rather than global statements in percentage. The relative probability of failure for fixed intervals is drawn from the number of controlled patients and the frequency of failure. The complementary probabilities of success are linked in their temporal sequence thus representing the probability of survival at a fixed endpoint. Necessary condition for the use of this procedure is the exact definition of moment and manner of failure. It is described how to establish survivorship tables.

[The value of the anamnesis for the probability diagnosis of shoulder pain]. / Die Bedeutung der Anamnese für die Wahrscheinlichkeitsdiagnose von Schulterschmerzen.

The response to pain of the shoulder in different diseases and injuries in this joint is uniform and this is of very little help in recognizing the cause. A detailed case history is useful in delineating the differential diagnosis. We have therefore developed a questionnaire consisting of 55 specifically aimed questions to these case histories. The acquired information was specifically rated for the 24 most frequent shoulderillnesses/injuries, and integrated in a computer program. In 55.4% of the cases the computer predicted the correct diagnosis and in 80% of the cases the right diagnosis was suggested amongst the first 3 preferences of the differential diagnosis.

[Sense and nonsense of knee orthosis]. / Sinn and Unsinn von Knieorthesen.

The trend for early mobility after surgical treatment of knee joint ligament injuries has led to the production of a large number of different braces in recent years. To allow an approximation of the very complex motion of the human knee, the use of braces with so-called physiological hinges has been recommended in the last few years. The authors report on a group of 50 patients who had sustained injuries to the cruciate ligament and had received IOWA knee braces following surgical treatment, the fit being subsequently checked by X-ray. These checks clearly demonstrated that the hinge of the brace hardly coincides with the knee axes and that there were deviations ranging from 1 to 4 cm. The authors therefore come to the conclusion that brace-fit must be checked by X-ray in all cases and that incorrectly fitted braces should be corrected before use. There is so far no evidence that so-called physiological hinges are really superior to braces with single axes. The current trends and developments cannot really be justified as long as there is no guarantee that the axes of brace and human knee coincide both in motion and during weight-bearing.

[The Kiel arthrograph--an instrument for recording active and passive shoulder joint mobility]. / Der Kieler Arthrograph--Ein Gerät zur Aufzeichnung der aktiven und passiven Schultergelenksbeweglichkeit.

The authors describe a new method for measuring the flexibility of the shoulder. They have designed a device consisting of two electrical goniometers to measure the horizontal and the vertical position of the humerus. A computer registers these signals, calculates the region of mobility as a sperical segment centered to the shoulder joint (caput humeri). This region is displayed in a map, called arthrogram. Slightly modified, the arthrograph measures the rotation of the humerus and depicts the rotation angle into the map, at the site of the measurement. First results are reported. The procedure is reproducible with an error less than 5 degrees. Arthrograms of sound persons are compared to those of different pathological symptoms. Arthrograms show more information than single angular values. They can be viewed easily, e.g. to control the success of a treatment.

[Is the implantation of hinged knee joint prostheses still justifiable today? 15 years' experience using the Blauth knee joint prosthesis]. / Ist die Implantation von Kniegelenkscharnierendoprothesen heute noch vertretbar? 15 Jahre Erfahrungen mit der Kniegelenkendoprothese nach Blauth.

In objection to knee hinge prostheses there is often mentioned a higher complication rate. An increased load impact on the bone-cement interface results from the close connection of tibial and femoral components. This is assumed to cause bad results, as reported from early artificial knee joint replacements, characterised by weight bearing axes and direct contact metal to metal. These are contrasted to long term results of the Blauth hinge prosthesis. The Blauth prosthesis is constructed according to the low friction principle without a weightbearing axis. A prospective multicentric long term follow-up study reports on 556 prostheses. 463 (83%) were controlled between 1 and 15 years after operation (average: 43 months). Aseptic loosenings had to be confirmed in 1.3% of the patients, deep infections in 2.6%. The survival analysis did not show an erratic deterioration in dependence of the observation period. After 10 years there is still a probability of 89% that a prosthesis does not show a deep infection or loosening. The efficiency of artificial knee joint replacement by hinge joints should therefore not be judged on the results of the first generation of these models.