9 results on '"Hackl, Michael"'
Search Results
2. Computed tomography-based angle measurements of the sagittal capitulum and trochlea position in relation to the humeral shaft
- Author
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Przyklenk, Axel, Hackl, Michael, Iuga, Andra-Iza, Leschinger, Tim, Maintz, David, Harbrecht, Andreas, Müller, Lars Peter, and Wegmann, Kilian
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- 2023
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3. Imaging diagnosis of radial head fractures—evaluation of plain radiography vs. CT scans
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Zhao, Zhenhua, Lyu, Yiming, Leschinger, Tim, Wegmann, Kilian, Müller, Lars Peter, and Hackl, Michael
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- 2021
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4. Mayo classification of olecranon fractures revisited -- Assessment of intra- and interobserver reliability based on CT scans.
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Harbrecht, Andreas, Hackl, Michael, Ott, Nadine, Uschok, Stephan, Wegmann, Kilian, Müller, Lars P., and Leschinger, Tim
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COMPUTED tomography ,RESEARCH evaluation ,DESCRIPTIVE statistics ,ELBOW fractures ,STATISTICS ,X-rays ,COMPARATIVE studies ,INTER-observer reliability ,EVALUATION - Abstract
Purpose: Olecranon fractures are classified using the commonly accepted Mayo classification. Its reliability has been analyzed by means of radiographs. A CT scan is often obtained due to joint involvement. Purpose of this study was to evaluate the intra- and interobserver reliability of the Mayo classification based on CT examination. Methods: Radiographic and CT images of 20 olecranon fractures were classified by four surgeons at two time points 30 days apart. Intra- and interobserver reliability were assessed using kappa coefficients. Results: Mean intraobserver reliability between X-rays was substantial and between CTs almost perfect (0.76 and 0.82, respectively). Mean interobserver reliability was fair for X-rays and moderate for CTs (0.32 and 0.44, respectively). Conclusion: Despite the more detailed imaging compared with radiography only moderate interobserver reliability was found for the classification of olecranon fractures based on CT imaging. This might lead to inconsistent fracture classification in both scientific and clinical setting. [ABSTRACT FROM AUTHOR]
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- 2024
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5. Correlation of head screw lengths in proximal humerus nailing: a CT-based study on 289 cases.
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Sarter, Michael, Koslowsky, Thomas C., Fervers, Philipp, Bratke, Grischa, Harbrecht, Andreas, Hackl, Michael, Müller, Lars P., and Wegmann, Kilian
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HUMERUS ,INTRAMEDULLARY fracture fixation ,HUMERAL fractures ,SCREWS ,PATIENT positioning ,COMPUTED tomography - Abstract
Introduction: Nailing of the proximal humerus is an established method for the treatment of proximal humerus fractures. Choice of the correct length for potentially four proximal locking screws is essential for postoperative outcome. Due to positioning of the patient, intraoperative determination of the correct length of the anteroposterior (AP) screw with the x-ray beam is particularly challenging even for experienced surgeons. We hypothesized that there would be a correlation between the projected lengths of the different proximal locking screws and therefore the length of the AP-screw could be determined based on the three lateromedial (LM) screws. Materials and methods: In this retrospective study (level of evidence: III) CT-scans of shoulders of 289 patients were 3D reconstructed with the program Horos. Using the manufacturer Stryker's instructions, the four proximal locking screws of the T2 Humeral Nail system were reproduced in the 3D reconstructed shoulders. The length of the AP-screw was correlated with the lengths of the LM-screws by Linear Regression and Multiple Linear Regression. Results: The results of this study showed that the lengths of proximal locking screws in proximal humeral nailing correlated significantly with each other. Based on the given data, a formula could be established to calculate the length of the AP-screw based on the lengths of the LM-screws with a probability of 76.5%. Conclusions: This study was able to show that the length of the AP-screw could be determined from the intraoperatively measured lengths of the LM-screws. As our findings base on measurements performed in CT scans, clinical studies are needed to support our data. [ABSTRACT FROM AUTHOR]
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- 2023
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6. Influence of rotator cuff preload on fracture configuration in proximal humerus fractures: a proof of concept for fracture simulation.
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Lenz, Maximilian, Kahmann, Stephanie, Behbahani, Mehdi, Pennig, Lenhard, Hackl, Michael, Leschinger, Tim, Müller, Lars Peter, and Wegmann, Kilian
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HUMERAL fractures ,PROOF of concept ,SHOULDER ,BONE density ,SURGICAL education ,ROTATOR cuff ,COMPUTED tomography - Abstract
Introduction: In regard of surgical training, the reproducible simulation of life-like proximal humerus fractures in human cadaveric specimens is desirable. The aim of the present study was to develop a technique that allows simulation of realistic proximal humerus fractures and to analyse the influence of rotator cuff preload on the generated lesions in regards of fracture configuration. Materials and methods: Ten cadaveric specimens (6 left, 4 right) were fractured using a custom-made drop-test bench, in two groups. Five specimens were fractured without rotator cuff preload, while the other five were fractured with the tendons of the rotator cuff preloaded with 2 kg each. The humeral shaft and the shortened scapula were potted. The humerus was positioned at 90° of abduction and 10° of internal rotation to simulate a fall on the elevated arm. In two specimens of each group, the emergence of the fractures was documented with high-speed video imaging. Pre-fracture radiographs were taken to evaluate the deltoid-tuberosity index as a measure of bone density. Post-fracture X-rays and CT scans were performed to define the exact fracture configurations. Neer's classification was used to analyse the fractures. Results: In all ten cadaveric specimens life-like proximal humerus fractures were achieved. Two III-part and three IV-part fractures resulted in each group. The preloading of the rotator cuff muscles had no further influence on the fracture configuration. High-speed videos of the fracture simulation revealed identical fracture mechanisms for both groups. We observed a two-step fracture mechanism, with initial impaction of the head segment against the glenoid followed by fracturing of the head and the tuberosities and then with further impaction of the shaft against the acromion, which lead to separation of the tuberosities. Conclusion: A high energetic axial impulse can reliably induce realistic proximal humerus fractures in cadaveric specimens. The preload of the rotator cuff muscles had no influence on initial fracture configuration. Therefore, fracture simulation in the proximal humerus is less elaborate. Using the presented technique, pre-fractured specimens are available for real-life surgical education. Level of Evidence: III. [ABSTRACT FROM AUTHOR]
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- 2023
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7. Radial head fractures with interposed capitellar cartilage fragment–hindrance to bone healing–a case series.
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Harbrecht, Andreas, Hackl, Michael, Leschinger, Tim, Wegmann, Kilian, Seybold, Dominik, and Müller, Lars P.
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RADIAL head & neck fractures , *ELBOW injuries , *ELBOW dislocation , *CARTILAGE , *COMPUTED tomography , *FRACTURE healing , *OPEN reduction internal fixation - Abstract
Introduction: Radial head fractures account for the majority of bony elbow injuries. The individual treatment options have been described in detail. In some cases, however, an unusual concomitant injury occurs, which can significantly impede primary osteosynthesis and healing. This concomitant injury can be an interposing cartilaginous capitellar fragment. Methods: This retrospective study describes four cases of trapped cartilage fragments of the capitellum that compromised primary osteosynthesis or primary conservative healing of a radial head fracture. Radiological imaging, function and pain level are presented pre- and postoperatively (mean follow-up 9.25 months). Results: None of the four cases showed preoperative evidence of an incarcerated cartilage fragment of the capitellum. They all showed limited elbow range of motion. CT examinations were performed in all cases. In each case, the cartilage fragment was first sighted upon surgery, subsequently removed and the fractures treated with ORIF. Mean follow-up was of 9.25 months. All fractures healed, with excellent function and low pain scores. Conclusions: This study presents rare cases of a trapped humeral cartilage fragment in radial head fractures. Radiological imaging including CT scans cannot reliably detect this concomitant injury. Therefore, this problem becomes apparent and treatable only during surgery. A high degree of suspicion is necessary especially in patients with minimally displaced fractures associated with limited elbow motion and a gap at the fracture site as treating these injuries conservatively may lead to poor outcome. [ABSTRACT FROM AUTHOR]
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- 2021
- Full Text
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8. Intra-individual variance of bilateral femoro-tibial leg rotation: a CT study of 105 healthy subjects.
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Ries, Christian, Boese, Christoph Kolja, Ott, Nadine, Doerner, Jonas, Müller, Lars Peter, and Hackl, Michael
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LEG ,COMPUTED tomography ,FEMUR ,TORSION abnormality (Anatomy) ,LEG muscles ,PATHOLOGICAL anatomy - Abstract
Purpose: In cases of suspected rotational deformity of the lower limb, in particular in post-traumatic malalignment following closed nailing, there is a lack of adequate reference values. Available publications on leg rotation have either small sample sizes or do not include bilateral or whole leg rotation of healthy legs. This study aimed to determine side-specific reference values of lower limb rotation in a large healthy sample. This may be helpful in acute clinical settings as well as for medical expert opinion. Methods: 226 consecutive bilateral lower limb computed tomography (CT) angiographies were screened. 105 patients (210 legs) were included (40 females, 65 males, mean age 67 ± 12 years). Bilateral axial femoral and tibial rotation alignment were independently measured and overall leg rotation was computed by two methods. Distributions, sex, and side differences were analyzed. Results: Two-sided paired t tests showed significant differences between right and left for all measurements. The left side showed a more pronounced mean anteversion in the femur of 2.2° (p = 0.002) and the right side higher mean external rotation in the tibia of 2.8° (p < 0.001). Overall leg rotation showed 5.1° more mean external rotation on the right side (p < 0.001) with both methods. Absolute side-to-side whole leg rotation difference was 9.5°. Absolute differences between both methods were 3.3°. The variance was high. 23 femora were retroverted, 1 tibia internally rotated, and 9 legs were overall internally rotated. No variables differed between female and male subjects except for femoral version (right p = 0.003 and left p = 0.002). Correlation coefficients were high (rho 0.550–0.934, all p < 0.001). Conclusion: There is a significant prevalence of side-to-side asymmetry in femoro-tibial torsion. Although side-to-side differences are not extraordinary, comparative axial femoro-tibial rotation alignment should always be interpreted with caution. Level of evidence: Diagnostic, retrospective cohort study, level III. [ABSTRACT FROM AUTHOR]
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- 2021
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9. Anteromedial coronoid facet fractures and associated ligament lesions: A case series.
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Lanzerath, Fabian, Hochberger, Felix, Ott, Nadine, Hackl, Michael, Wegmann, Kilian, Müller, Lars P., and Leschinger, Tim
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COLLATERAL ligament , *ULNAR nerve , *ULNAR collateral ligament , *LIGAMENTS , *KNEE injuries , *COMPUTED tomography , *ACHILLES tendon rupture - Abstract
• Fractures of the anteromedial facet of the coronoid require addressing as combined osteoligamentous injuries. • With a rupture rate of 91.7% in this cohort, the MCL appears to be more frequently affected than previously suggested. • The presented systematic algorithm might save the lateral approach through the medial start of the procedure in subtype 2 and 3 fractures of the anteromedial facet in certain cases. Varus posteromedial rotational injury mechanisms lead to fractures of the coronoids process' anteromedial facet. As these fractures are often unstable, rapid fracture treatment is vital to prevent progressive osteoarthritis. Twelve patients with a fracture of the anteromedial facet treated surgically were enrolled in the study. Computed tomography images were used to classify the fractures according to the system by O'Driscoll et al. Clinical follow-up included each patient's medical record, surgical treatment algorithm, all complications encountered during the follow-up period, Disabilities of the arm, shoulder, and hand score, subjective elbow value, and pain. A total of 8 men (66.7%) and 4 women (33.3%) were treated surgically and followed-up after a mean period of 45 ± 23 months. The mean DASH score was 11.9 ± 12.9 points. One patient complained of transient neuropathy in the innervation area of the ulnar nerve, however, this existed already pre-operatively and resolved after less than three months. The presented patient cohort shows that AMF fracture of the coronoid process are unstable lesions according to the bony instability and the frequently ruptured collateral ligament complexes which need to be addressed. The MCL seems to be affected more frequently than previously appreciated. Level IV; Case Series; Treatment Study. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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