@phdthesis{Luetkens2019,
  author    = {Luetkens, Karsten Sebastian},
  title     = {Einfluss der chirurgischen Expertise auf die postoperative Morbidit{\"a}t am Beispiel der Ileostomar{\"u}ckverlagerung - eine retrospektive Analyse an 558 Patienten},
  doi       = {10.25972/OPUS-18566},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-185662},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2019},
  abstract  = {Ein protektives Ileostoma reduziert die schweren klinischen Folgen einer Anastomoseninsuffizienz nach Darmresektion wie Abszess, Sepsis und Tod. Die R{\"u}ckverlagerung des Ileostomas ist selbst mit einer nennenswerten Morbidit{\"a}ts- (3-40\%) und Mortalit{\"a}tsrate (0-4\%) verkn{\"u}pft. Dennoch gilt die ISRV als Ausbildungseingriff junger chirurgischer Weiterbildungsassistenten. In dieser Arbeit wurden alle erwachsene Patienten (n = 558), die eine ISRV im Zeitraum zwischen September 2008 und Januar 2017 erhalten haben, anhand einer prospektiv gesammelten Datenbank ermittelt und retrospektiv anhand der Patientenakten ausgewertet. Dabei wurden neben den Basis-Charakteristika der Patienten (Alter, Krankenversicherung, ASA, BMI, Raucheranamnese, Immunsuppression) und operativen Daten (Verschlusstechnik, Operationsdauer, Rate der segmentalen Darmresektionen, Adh{\"a}siolyse) erfasst. Die postoperativen Komplikationsraten, gemessen anhand der Clavien- Dindo-Klassifikation, und die L{\"a}nge des postoperativen Krankenhausaufenthaltes, wurden in Bezug auf den Ausbildungsstand des Operateurs analysiert. In der Facharzt-Kohorte (355 Patienten) zeigte sich eine signifikant k{\"u}rzere Operationsdauer. Unter Ber{\"u}cksichtigung m{\"o}glicher St{\"o}rfaktoren zeigte sich kein signifikanter Unterschied zwischen beiden Gruppen bez{\"u}glich Major- Komplikationen. Die Rate an Anastomoseninsuffizienzen betrug 3\% und die Gesamt-Morbidit{\"a}tsrate 11\%. Da sich nur die Operationsdauer abh{\"a}ngig vom Ausbildungsstand des Chirurgen unterschiedlich zeigte, kann die ISRV als guter Ausbildungseingriff f{\"u}r junge chirurgische Assistenten in Weiterbildung gesehen werden.},
  subject      = {Ileostomar{\"u}ckverlagerung},
  language  = {de}
}
@article{LuetkensErguenHuflageetal.2021,
  author    = {Luetkens, Karsten Sebastian and Erg{\"u}n, S{\"u}leyman and Huflage, Henner and Kunz, Andreas Steven and Gietzen, Carsten Herbert and Conrads, Nora and Pennig, Lenhard and Goertz, Lukas and Bley, Thorsten Alexander and Gassenmaier, Tobias and Grunz, Jan-Peter},
  title     = {Dose reduction potential in cone-beam CT imaging of upper extremity joints with a twin robotic x-ray system},
  series = {Scientific Reports},
  volume    = {11},
  journal   = {Scientific Reports},
  number    = {1},
  doi       = {10.1038/s41598-021-99748-1},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-270429},
  year      = {2021},
  abstract  = {Cone-beam computed tomography is a powerful tool for 3D imaging of the appendicular skeleton, facilitating detailed visualization of bone microarchitecture. This study evaluated various combinations of acquisition and reconstruction parameters for the cone-beam CT mode of a twin robotic x-ray system in cadaveric wrist and elbow scans, aiming to define the best possible trade-off between image quality and radiation dose. Images were acquired with different combinations of tube voltage and tube current-time product, resulting in five scan protocols with varying volume CT dose indices: full-dose (FD; 17.4 mGy), low-dose (LD; 4.5 mGy), ultra-low-dose (ULD; 1.15 mGy), modulated low-dose (mLD; 0.6 mGy) and modulated ultra-low-dose (mULD; 0.29 mGy). Each set of projection data was reconstructed with three convolution kernels (very sharp [Ur77], sharp [Br69], intermediate [Br62]). Five radiologists subjectively assessed the image quality of cortical bone, cancellous bone and soft tissue using seven-point scales. Irrespective of the reconstruction kernel, overall image quality of every FD, LD and ULD scan was deemed suitable for diagnostic use in contrast to mLD (very sharp/sharp/intermediate: 60/55/70\%) and mULD (0/3/5\%). Superior depiction of cortical and cancellous bone was achieved in FD\(_{Ur77}\) and LD\(_{Ur77}\) examinations (p < 0.001) with LD\(_{Ur77}\) scans also providing favorable bone visualization compared to FD\(_{Br69}\) and FD\(_{Br62}\) (p < 0.001). Fleiss' kappa was 0.618 (0.594-0.641; p < 0.001), indicating substantial interrater reliability. In this study, we demonstrate that considerable dose reduction can be realized while maintaining diagnostic image quality in upper extremity joint scans with the cone-beam CT mode of a twin robotic x-ray system. Application of sharper convolution kernels for image reconstruction facilitates superior display of bone microarchitecture.},
  language  = {en}
}
@article{HeinzMellerLuetkensetal.2022,
  author    = {Heinz, Tizian and Meller, Felix and Luetkens, Karsten Sebastian and Horas, Konstantin and Sch{\"a}fer, Thomas and Rudert, Maximilian and Reppenhagen, Stephan and Weißenberger, Manuel},
  title     = {Can the MRI based AMADEUS score accurately assess pre-surgery chondral defect severity according to the ICRS arthroscopic classification system?},
  series = {Journal of Experimental Orthopaedics},
  volume    = {9},
  journal   = {Journal of Experimental Orthopaedics},
  number    = {1},
  issn      = {2197-1153},
  doi       = {10.1186/s40634-022-00511-w},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300781},
  year      = {2022},
  abstract  = {Purpose The AMADEUS (Area Measurement And DEpth and Underlying Structures) scoring and grading system has been proposed for the MRI based evaluation of untreated focal chondral defects around the knee. The clinical practicability, its correlation with arthroscopically assessed grading systems (ICRS - International Cartilage Repair Society) and thereby its clinical value in terms of decision making and guiding prognosis was yet to determine. Methods From 2008 to 2019 a total of 89 individuals were indicated for high tibial valgus osteotomy (HTO) due to tibial varus deformity and concomitant chondral defects of the medial compartment of the knee. All patients received a preoperative MRI (1.5 Tesla or 3.0 Tesla) and pre-osteotomy diagnostic arthroscopy. Chondral defects of the medial compartment were scored and graded with the MRI based AMADEUS by three independent raters and compared to arthroscopic defect grading by the ICRS system. Interrater and intrarater reliability as well as correlation analysis with the ICRS classification system were assessed. Results Intraclass correlation coefficients for the various subscores of the AMADEUS showed an overall good to excellent interrater agreement (min: 0.26, max: 0.80). Intrarater agreement turned out to be substantially inferior (min: 0.08, max: 0.53). Spearman correlation revealed an overall moderate correlative association of the AMADEUS subscores with the ICRS classification system, apart from the defect area subscore. Sensitivity of the AMADEUS to accurately identify defect severity according to the ICRS was 0.7 (0.69 for 3.0 Tesla MRI, 0.67 for 1.5 Tesla MRI). The mean AMADEUS grade was 2.60 ± 0.81 and the mean ICRS score 2.90 ± 0.63. Conclusions Overall, the AMADEUS with all its subscores shows moderate correlation with the arthroscopic chondral grading system according to ICRS. This suggests that chondral defect grading by means of the MRI based AMADEUS is well capable of influencing and guiding treatment decisions. Interrater reliability shows overall good agreement.},
  language  = {en}
}
@article{GietzenKunzLuetkensetal.2022,
  author    = {Gietzen, Carsten Herbert and Kunz, Andreas Steven and Luetkens, Karsten Sebastian and Huflage, Henner and Christopoulos, Georgios and van Schoonhoven, J{\"o}rg and Bley, Thorsten Alexander and Schmitt, Rainer and Grunz, Jan-Peter},
  title     = {Evaluation of prestyloid recess morphology and ulnar-sided contrast leakage in CT arthrography of the wrist},
  series = {BMC Musculoskeletal Disorders},
  volume    = {23},
  journal   = {BMC Musculoskeletal Disorders},
  number    = {1},
  doi       = {10.1186/s12891-022-05241-9},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-301113},
  year      = {2022},
  abstract  = {Background In wrist arthrograms, aberrant contrast material is frequently seen extending into the soft tissue adjacent to the ulnar styloid process. Since the prestyloid recess can mimic contrast leakage in CT arthrography, this study aims to provide a detailed analysis of its morphologic variability, while investigating whether actual ulnar-sided leakage is associated with injuries of the triangular fibrocartilage complex (TFCC). Methods Eighty-six patients with positive wrist trauma history underwent multi-compartment CT arthrography (40 women, median age 44.5 years). Studies were reviewed by two board-certified radiologists, who documented the morphology of the prestyloid recess regarding size, opening type, shape and position, as well as the presence or absence of ulnar-sided contrast leakage. Correlations between leakage and the presence of TFCC injuries were assessed using the mean square contingency coefficient (r\(_{ɸ}\)). Results The most common configuration of the prestyloid recess included a narrow opening (73.26\%; width 2.26 ± 1.43 mm), saccular shape (66.28\%), and palmar position compared to the styloid process (55.81\%). Its mean length and anterior-posterior diameter were 6.89 ± 2.36 and 5.05 ± 1.97 mm, respectively. Ulnar-sided contrast leakage was reported in 29 patients (33.72\%) with a mean extent of 12.30 ± 5.31 mm. Leakage occurred more often in patients with ulnar-sided TFCC injuries (r\(_{ɸ}\) = 0.480; p < 0.001), whereas no association was found for lesions of the central articular disc (r\(_{ɸ}\) = 0.172; p = 0.111). Conclusions Since ulnar-sided contrast leakage is more common in patients with peripheral TFCC injuries, distinction between an atypical configuration of the prestyloid recess and actual leakage is important in CT arthrography of the wrist.},
  language  = {en}
}
@article{PatzerKunzHuflageetal.2023,
  author    = {Patzer, Theresa Sophie and Kunz, Andreas Steven and Huflage, Henner and Conrads, Nora and Luetkens, Karsten Sebastian and Pannenbecker, Pauline and Paul, Mila Marie and Erg{\"u}n, S{\"u}leyman and Bley, Thorsten Alexander and Grunz, Jan-Peter},
  title     = {Ultrahigh-resolution photon-counting CT in cadaveric fracture models: spatial frequency is not everything},
  series = {Diagnostics},
  volume    = {13},
  journal   = {Diagnostics},
  number    = {10},
  issn      = {2075-4418},
  doi       = {10.3390/diagnostics13101677},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-319281},
  year      = {2023},
  abstract  = {In this study, the impact of reconstruction sharpness on the visualization of the appendicular skeleton in ultrahigh-resolution (UHR) photon-counting detector (PCD) CT was investigated. Sixteen cadaveric extremities (eight fractured) were examined with a standardized 120 kVp scan protocol (CTDI\(_{vol}\) 10 mGy). Images were reconstructed with the sharpest non-UHR kernel (Br76) and all available UHR kernels (Br80 to Br96). Seven radiologists evaluated image quality and fracture assessability. Interrater agreement was assessed with the intraclass correlation coefficient. For quantitative comparisons, signal-to-noise-ratios (SNRs) were calculated. Subjective image quality was best for Br84 (median 1, interquartile range 1-3; p ≤ 0.003). Regarding fracture assessability, no significant difference was ascertained between Br76, Br80 and Br84 (p > 0.999), with inferior ratings for all sharper kernels (p < 0.001). Interrater agreement for image quality (0.795, 0.732-0.848; p < 0.001) and fracture assessability (0.880; 0.842-0.911; p < 0.001) was good. SNR was highest for Br76 (3.4, 3.0-3.9) with no significant difference to Br80 and Br84 (p > 0.999). Br76 and Br80 produced higher SNRs than all kernels sharper than Br84 (p ≤ 0.026). In conclusion, PCD-CT reconstructions with a moderate UHR kernel offer superior image quality for visualizing the appendicular skeleton. Fracture assessability benefits from sharp non-UHR and moderate UHR kernels, while ultra-sharp reconstructions incur augmented image noise.},
  language  = {en}
}
@article{ConradsGrunzHuflageetal.2023,
  author    = {Conrads, Nora and Grunz, Jan-Peter and Huflage, Henner and Luetkens, Karsten Sebastian and Feldle, Philipp and Grunz, Katharina and K{\"o}hler, Stefan and Westermaier, Thomas},
  title     = {Accuracy of pedicle screw placement using neuronavigation based on intraoperative 3D rotational fluoroscopy in the thoracic and lumbar spine},
  series = {Archives of Orthopaedic and Trauma Surgery},
  volume    = {143},
  journal   = {Archives of Orthopaedic and Trauma Surgery},
  number    = {6},
  doi       = {10.1007/s00402-022-04514-1},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-324966},
  pages     = {3007-3013},
  year      = {2023},
  abstract  = {Introduction In spinal surgery, precise instrumentation is essential. This study aims to evaluate the accuracy of navigated, O-arm-controlled screw positioning in thoracic and lumbar spine instabilities. Materials and methods Posterior instrumentation procedures between 2010 and 2015 were retrospectively analyzed. Pedicle screws were placed using 3D rotational fluoroscopy and neuronavigation. Accuracy of screw placement was assessed using a 6-grade scoring system. In addition, screw length was analyzed in relation to the vertebral body diameter. Intra- and postoperative revision rates were recorded. Results Thoracic and lumbar spine surgery was performed in 285 patients. Of 1704 pedicle screws, 1621 (95.1\%) showed excellent positioning in 3D rotational fluoroscopy imaging. The lateral rim of either pedicle or vertebral body was protruded in 25 (1.5\%) and 28 screws (1.6\%), while the midline of the vertebral body was crossed in 8 screws (0.5\%). Furthermore, 11 screws each (0.6\%) fulfilled the criteria of full lateral and medial displacement. The median relative screw length was 92.6\%. Intraoperative revision resulted in excellent positioning in 58 of 71 screws. Follow-up surgery due to missed primary malposition had to be performed for two screws in the same patient. Postsurgical symptom relief was reported in 82.1\% of patients, whereas neurological deterioration occurred in 8.9\% of cases with neurological follow-up. Conclusions Combination of neuronavigation and 3D rotational fluoroscopy control ensures excellent accuracy in pedicle screw positioning. As misplaced screws can be detected reliably and revised intraoperatively, repeated surgery for screw malposition is rarely required.},
  language  = {en}
}