Publications (5)14.07 Total impact
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Article: [Preventing malrotation during intramedullary nailing of femoral fractures].
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ABSTRACT: The problem of preventing malrotation after closed intramedullary nailing of femoral shaft fractures has not been solved yet. As clinical tests and radiologic criteria for intraoperative use provide little accuracy, the theoretical basis for a C-arm-based measurement of the femoral antetorsion was analysed. The directions of femoral neck axis and condylar axis can be identified by the radiologic views "knee joint, lateral view" and "hip joint, axial view". The rotation of the C-arm in relation to a horizontal axis to achieve these views can be measured in degrees. Theoretically, the difference between these rotation angles could be used to calculate the antetorsion. Intact plastic femora (Sawbone) and a femoral shaft fracture model were used to research optical and geometrical phenomena that influence a direct measuring technique. Several geometrical phenomena were observed, making direct measurement with arithmetic corrective factors not recommendable. For practical reasons, a data table was created, correlating the difference between the two C-arm angles with true antetorsion. In an interobserver trial with 18 trauma surgeons, the method proved to achieve high accuracy with a maximum interobserver variation of 5 degrees. The method is easily reproducible, reliable and can be recommended to every surgeon. Due to the wide range of physiological antetorsion angles in different individuals, fair results can be expected controlling the rotation with standard value tables, and excellent results can be expected using bilateral measurement.Der Unfallchirurg 11/2006; 109(10):855-61. · 0.61 Impact Factor -
Article: Balloon angioplasty of arteries of the upper extremities in patients with extracranial giant-cell arteritis.
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ABSTRACT: To evaluate the outcome of balloon angioplasty in the arteries of the upper extremities in patients with giant-cell arteritis (GCA) and stenosing extracranial involvement. Percutaneous transluminal angioplasty (PTA) for symptomatic upper limb artery stenoses (n = 29) and occlusions (n = 1) resistant to medical treatment was carried out in 10 patients (all women, mean age 65 years) with GCA. Vascular lesions were located in the subclavian (n = 4), axillary (n = 10) and brachial (n = 16) arteries. Interventional treatment was accompanied by immunosuppressive drugs in all patients. Follow-up included clinical and serological examination, magnetic resonance angiography and colour duplex ultrasound. Initial technical success of angioplasty was achieved in the case of all vascular lesions. In five patients, marked recurrent stenoses (vascular territories; n = 10/30) were found during follow-up (mean 24 months). The cumulative primary patency rate was 65.2%. All recurrent lesions developed in the territories of the initial long-segment stenoses. Repeated PTA (vascular territories, n = 8; patients, n = 5) provided a cumulative secondary patency rate of 82.6% and a cumulative tertiary patency rate of 89.7%. Despite a tendency to restenoses, balloon angioplasty of the upper-extremity artery, in combination with immunosuppressive treatment, is an efficient method for the treatment of extracranial GCA.Annals of the Rheumatic Diseases 10/2006; 65(9):1124-30. · 8.73 Impact Factor -
Article: Bildwandlergestützte Vermeidung einer Torsionsabweichung zur Gegenseite bei der Oberschenkelmarknagelung
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ABSTRACT: HintergrundNach geschlossener Oberschenkelmarknagelung liegt laut publizierten CT-Reihenuntersuchungen die Wahrscheinlichkeit einer therapiebedrftigen Torsionsabweichung im Vergleich zur Gegenseite im zweistelligen Prozentbereich. Die bisher angegebenen klinischen und bildgebenden Verfahren zur intraoperativen Vermeidung dieser Abweichung unterliegen gewissen Ungenauigkeiten. In der vorliegenden Arbeit sollte festgestellt werden, ob sich mit Hilfe eines C-Bogens intraoperativ die Antetorsion verlsslich bestimmen lsst.Material und MethodenDie Technik basiert darauf, dass sich die Lage von Schenkelhals- und Kondylenebene im Raum durch exakt eingestellte Projektionen Knie seitlich und Hfte axial darstellen und dass sich die eingestellte Kippung des C-Bogens in Winkelgraden definieren lsst. An mehreren intakten Kunststofffemora sowie einem Kunststoffmodell einer frei einstellbaren Femurschaftquerfraktur wurde untersucht, inwieweit sich die Kippungswinkel des C-Bogens zur Bestimmung der Antetorsion verwenden lassen und welche Fehlerquellen die geplante Messtechnik beeinflussen knnen. Abschlieend wurde an 18 Unfallchirurgen eine Untersuchung zur Interobservergenauigkeit der entwickelten Methode durchgefhrt.Ergebnisse und SchlussfolgerungAus verschiedenen geometrischen und anatomischen Grnden heraus ist es nicht mglich, die Antetorsion als einfache Differenz der Winkel zu berechnen, in denen der C-Bogen fr eine axiale Hft- und eine seitliche Knieprojektion gekippt werden muss. Nach Identifikation mehrerer potentieller Fehlerquellen und Einflussfaktoren wurde eine Umrechnungstabelle erstellt, die fr den jeweils gemessenen Wert die echte Antetorsion ausgibt. Unter Bercksichtigung aller Faktoren liegt die Genauigkeit der Methode bei <5 Messfehler und damit innerhalb des nicht therapiebedrftigen Bereichs. Wegen leichter Anwendung und geringen Zusatzaufwands ist sie fr alle Flle mit nicht sicher zu bestimmender Torsion zu empfehlen.BackgroundThe problem of preventing malrotation after closed intramedullary nailing of femoral shaft fractures has not been solved yet. As clinical tests and radiologic criteria for intraoperative use provide little accuracy, the theoretical basis for a C-arm-based measurement of the femoral antetorsion was analysed.MethodsThe directions of femoral neck axis and condylar axis can be identified by the radiologic views knee joint, lateral view and hip joint, axial view. The rotation of the C-arm in relation to a horizontal axis to achieve these views can be measured in degrees. Theoretically, the difference between these rotation angles could be used to calculate the antetorsion. Intact plastic femora (Sawbone) and a femoral shaft fracture model were used to research optical and geometrical phenomena that influence a direct measuring technique.ResultsSeveral geometrical phenomena were observed, making direct measurement with arithmetic corrective factors not recommendable. For practical reasons, a data table was created, correlating the difference between the two C-arm angles with true antetorsion. In an interobserver trial with 18 trauma surgeons, the method proved to achieve high accuracy with a maximum interobserver variation of 5.ConclusionsThe method is easily reproducible, reliable and can be recommended to every surgeon. Due to the wide range of physiological antetorsion angles in different individuals, fair results can be expected controlling the rotation with standard value tables, and excellent results can be expected using bilateral measurement.Der Unfallchirurg 09/2006; 109(10):855-861. · 0.61 Impact Factor -
Article: Value of fat-suppressed proton-density-weighted turbo spin-echo sequences in detecting meniscal lesions: comparison with arthroscopy.
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ABSTRACT: To evaluate fat-suppressed (FS) proton-density-weighted (PDw) turbo spin-echo (TSE) magnetic resonance imaging (MRI) compared to arthroscopy in the detection of meniscal lesions. In a prospective study, 31 knee joints were imaged on a 1.5T MR scanner before arthroscopy using the following sequences: (a) coronal and sagittal FS-PDw TSE (TR/TE: 4009/15 ms); (b) coronal T1w SE (TR/TE: 722/20 ms), and sagittal PDw TSE (TR/TE: 3800/15 ms). Other imaging parameters were: slice thickness 3 mm, FOV 160 mm, matrix 256 x 256. A total of 186 meniscal regions (62 menisci; anterior horn, body, posterior horn) were evaluated. Standard of reference was arthroscopy. Sensitivity, specificity, negative predictive value (npv), positive predictive value (ppv), and accuracy were calculated. Arthroscopically, meniscal lesions were detected in 55/186 segments (35 medial and 20 lateral meniscal lesions). Sensitivity, specificity, npv, ppv, and accuracy for combination of coronal and sagittal FS PDw TSE were 91.4%, 98.3%, 95%, 97%, and 93.5% for the medial meniscus, and 90%, 98.6%, 97.3%, 94.7%, and 96.8% for the lateral. The results were comparable to the combination of coronal T1w SE and sagittal PDw TSE for the medial (88.6%, 98.3%, 93.4%, 96.9%, 91.4%) and the lateral (90%, 95.9%, 97.2%, 85.7%, 92.5%) meniscus. FS PDw TSE-MR sequences are an excellent alternative for the detection of meniscal lesions in comparison with diagnostic arthroscopy.Acta Radiologica 06/2006; 47(4):385-90. · 1.37 Impact Factor -
Article: [First clinical results in a study of contrast enhanced magnetic resonance angiography with the 1.0 molar gadobutrol in peripheral arterial occlusive disease--comparison to intraarterial DSA].
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ABSTRACT: To assess the value of contrast enhanced (CE)-MR angiography (MRA) with 1.0 molar Gadobutrol (Schering, Germany) in comparison to intraarterial DSA in peripheral arterial occlusive disease (PAOD). Within 48 hours, 30 symptomatic patients with PAOD were examined by CE-MRA (Gadobutrol dose 0.2-0.3 mmol/kg body weight) and DSA. For CE-MRA, a 1.5 T magnet (Vision, Siemens, Germany) was used (FA 35 degrees, TR/TE 4.6/1.8 ms, FOV 400 mm, matrix 230 x 512, total acquisition time 81 sec). Two radiologists evaluated a total of 600 vessel segments for stenotic lesions and image quality (1 = not visible to 5 = excellent). Treatment was independently planned on the basis of the MRA and DSA findings. The Kendall's tau-b coefficient was 0.92 for overall stenotic grading, and 0.92, 0.93 and 0.92, respectively, for the vascular flow in the iliac, femoropopliteal and crural arteries. Sensitivity, specificity, negative and positive predictive value, and accuracy were, respectively, 94, 97, 98 and 92, 96 % for > 50 % stenoses, 95, 99, 99, 95 and 99 % for iliac arteries, 96, 98, 98%, 94 and 97 % for femoropopliteal arteries, and 92, 94, 96, 89 and 94 % for crural arteries. Therapy planning by MRA and DSA coincided in 51 of 54 cases. No relevant adverse event occurred. CE-MRA with 1.0 molar Gadobutrol is highly efficient in diagnosing peripheral arterial occlusive disease and correlates excellently with DSA.RöFo - Fortschritte auf dem Gebiet der R 04/2003; 175(4):556-64. · 2.76 Impact Factor
