Michael Müller

Dr. Michael Müller

Department of Trauma Surgery, Klinikum rechts der Isar, Technical University of Munich, 81675 Munich, Germany
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Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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5 February 2022 in Injury
Verified
Journal Article
Closed access
Michael MüllerMichael Müller
Michael Müller
JHJ. Heck
J. Heck
PPP. Pflüger
P. Pflüger
FGF. Greve
F. Greve
PBP. Biberthaler
P. Biberthaler
MCM. Crönlein
M. Crönlein

Verified
Journal Article
Open access
PDF file
Michael MüllerMichael Müller
Michael Müller
AGAlexander Gutwerk
Alexander Gutwerk
FGFrederik Greve
Frederik Greve
LVLisa Völker
Lisa Völker
MZMichael Zyskowski
Michael Zyskowski
KBKarl Braun
Karl Braun
Background: Fractures of the proximal femur constitute daily work in orthopedic trauma surgery. With the continuous increase of obesity in the general population, surgeons face several known technical challenges. The aim of this study was to investigate the association of high body mass index (BMI) in patients with proximal femur fractures with intra- and postoperative adverse events, as well as with functional outcomes after successful surgery. Methods: In this retrospective, single-center cohort study, 950 patients who sustained a fracture of the proximal femur (femoral neck fracture or trochanteric fracture) and underwent surgical treatment at our level I trauma center between 2003 and 2015 were included. Patient-specific data were obtained in regard to demographics, comorbidities, and fracture morphology. In-hospital postoperative complications (i.e., need for revision surgery, wound site infection, pneumonia, urinary tract infection, necessary transfusion, and deep-vein thrombosis) were analyzed, along with the length of hospitalization and overall mortality rate. Functional outcome was assessed using the Barthel index and the patient’s ability to walk on crutches. Mortality rate and need for revision surgery were assessed over a two-year time period. Any adverse event was correlated to one of the four WHO’s BMI groups. Results: The cohort included 80 (8.4%) underweight patients, 570 (60.0%) normal weight patients, 241 (25.4%) overweight patients, and 59 (6.2%) obese patients. We found more femoral neck fractures (506, or 53%) than trochanteric fractures (444, or 47%). In bivariate analysis, no significant difference was found in regard to overall mortality or postoperative complications. Hospitalization time (LOS) differed between the underweight (12.3 ± 4.8 days), normal (13.6 ± 7.8 days), overweight (14.2 ± 11.7 days), and obese patients (16.0 ± 9.7 days) (p = 0.040). Operation time increased stepwise with increasing BMI: underweight = 85.3 ± 42.9 min; normal weight = 90.2 ± 38.2 min; overweight = 99.9 ± 39.9 min; obese = 117.2 ± 61.5 min (p < 0.001). No significant difference was found by analyzing functional outcomes. However, patients with intermediate BMI levels (18.5–30 kg/m2) tended to achieve the best results, as represented by a higher Barthel index score and the patient’s ability to walk on crutches. Conclusion: Increased BMI in patients with proximal femur fractures is associated with both longer operation time and length of hospitalization (LOS). Postoperative mobilization and functional outcomes appear to follow a reversed J-curve distribution (with overweight patients showing the best functional results), whereas both obese and underweight patients have associated poorer function.

25 August 2021 in Archives of orthopaedic and trauma surgery
Verified
Journal Article
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Michael MüllerMichael Müller
Michael Müller
FGF. Greve
F. Greve
MCM. Crönlein
M. Crönlein
MZM. Zyskowski
M. Zyskowski
SPS. Pesch
S. Pesch
MBM. Beirer
M. Beirer
Introduction: Surgical treatment of complex humeral head fractures in the elderly is challenging due to osteoporotic bone, comorbidities and reduced compliance. The treatment strategy (reconstruction versus replacement) should allow for a functional aftercare and result in a high patient satisfaction. Major complications leading to surgical revision are crucial and should be avoided. The purpose of this study was to analyse the major complication rate leading to surgical revision and the patient-based outcome in complex humeral head fractures of the elderly population treated either using locking plate fixation (LCP) or reversed total shoulder arthroplasty (rTSA). Materials and Methods: All patients older than 65 years surgically treated due to a four-part fracture of the proximal humerus between 2003 and 2015 were enrolled in our retrospective study. Major complications and revision rates were recorded and functional outcome was assessed using the Munich Shoulder Questionnaire (MSQ) allowing for qualitative self-assessment of the Shoulder Pain and Disability Index (SPADI), of the Disability of the Arm, Shoulder and Hand (DASH) score and of the Constant Score. Results: A cohort of 103 patients with a mean age of 73.4 ± 6.2 years suffering from four-part fractures of the humeral head were enrolled. 63 patients were treated using the LCP fixation compared to 40 rTSAs. There were no significant differences in the patient-reported functional outcome. The revision rate was significantly higher in the LCP group (10/63; 15.9%) compared to the rTSA group (1/40; 2.5%). Reasons for revision were avascular head necrosis, cut-out of screws, secondary dislocation of the greater tuberosity and hypersensitivity to metal. Conclusions: Reversed total shoulder arthroplasty and locking plate fixation are both established surgical procedures for the management of complex proximal humerus fractures in the elderly leading to similar functional results. However the revision rate in the rTSA group was significantly lower. Primary rTSA should, therefore, be favoured in multimorbid elderly patients with an increased complication risk to avoid repeated anaesthesia.

2 December 2022 in Journal of Clinical Medicine
Verified
Journal Article
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MZMichael Zyskowski
Michael Zyskowski
MWMarkus Wurm
Markus Wurm
FGFrederik Greve
Frederik Greve
PZPhilipp Zehnder
Philipp Zehnder
PPPatrick Pflüger
Patrick Pflüger
Chlodwig KirchhoffChlodwig Kirchhoff
Chlodwig Kirchhoff
(1) Background: As age in western populations is rising, so too are fractures, e.g., of the distal fibula. The aim of this study was to find out whether a novel, minimally invasive intramedullary osteosynthesis technique for the treatment of distal fibula fractures in elderly patients results in not only a reduction of postoperative complications, but also a shorter hospitalization time, an improved clinical outcome, and preserved autonomy in geriatric trauma patients. (2) Methods: In this prospective study, the results following surgical treatment for distal fibula fractures in geriatric patients after using DePuy Synthes® one-third semitubular plate (Group I) or a minimally invasive intramedullary photodynamic Bone StabilizationSystem (IlluminOss®) (Group II) were compared at 6 weeks, 12 weeks, 6 months, and 1 year after initial treatment. (3) Results: Significant improvement regarding clinical outcome was shown in Group II 6 and 12 weeks after surgery. (4) Conclusions: Our study results demonstrate that the use of this new intramedullary stabilization system in combination with an immediate postoperative weight bearing seems to be a safe and stable treatment option for ankle fractures in geriatric patients, especially in the early stages of recovery.

9 September 2023 in Journal of Clinical Medicine
Verified
Journal Article
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Michael MüllerMichael Müller
Michael Müller
VMVerena Mann
Verena Mann
JZJulian Zapf
Julian Zapf
KKKonstantin Kirchhoff
Konstantin Kirchhoff
MZMichael Zyskowski
Michael Zyskowski
MWMarkus Wurm
Markus Wurm
Background: Fractures of the radial head are common injuries, whereas, in the case of displaced fractures, surgical treatment using screw or plate osteosynthesis, excision, or replacement of the radial head is required. However, data about patient-related outcomes (PROM) for different types of radial head fractures is limited in the current literature. Therefore, this study was conducted to evaluate the functional outcome after operatively treated radial head fractures and to further correlate these results with the initial modified Mason classification. Methods: In this retrospective study, all suitable patients with surgical treatment of a radial head fracture were identified. Only patients with Mason II-IV fractures were included. All patients completed the Elbow Self-Assessment Score (ESAS) questionnaire. Data on fracture classification, type of surgery, and revision operations (if needed) were assessed. Results: A total of 92 patients suffering from fractures of the radial head (57 Mason II, 35 Mason III-fractures) who were operatively treated at our institution were enrolled. There were 42 (47.7%) female and 50 (54.3%) male patients with an average age of 47.5 ± 14.1 years. Screw osteosynthesis was performed in 67 patients, plate osteosynthesis in 20 patients, and five patients received radial head arthroplasty. The average ESAS score accounted for 89.7 ± 16.7. Mason II fractures showed significantly better functional results with higher ESAS scores (92.3 ± 13.9 vs. 85.4 ± 20.1) as well as significantly lower rates of necessary implant removal (0 vs. 5 (14.3%) than Mason III fractures. Screw osteosynthesis showed significantly better functional ESAS scores, 91.0 ± 16.5, than plate osteosynthesis, with 85.3 ± 17.6 (p = 0.041), but was predominantly used in Mason II fractures. Conclusions: Surgical treatment using screw- and plate osteosynthesis of radial head fractures provides a good overall outcome. The postoperative function is associated with the initial Mason classification as the patients’ reported outcome was worse in Mason III fractures compared to Mason type II fractures. In this context, the ESAS score can be considered a useful tool for the assessment of the patient-based functional outcome.

28 September 2018 in European Journal of Medical Research
Verified
Journal Article
Open access
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FGFrederik Greve
Frederik Greve
KBKarl Braun
Karl Braun
VVVeronika Vitzthum
Veronika Vitzthum
MZMichael Zyskowski
Michael Zyskowski
Michael MüllerMichael Müller
Michael Müller
MBMarc Beirer
Marc Beirer
There are many approved patient-related outcome measurement tools regarding ankle pathologies. However, there is none incorporating the range of motion (ROM) as an objective parameter. Most instruments focus on subjective parameters such as pain and impairment at work or daily living. Furthermore, the majority is only applicable to a specific pathology. Therefore, the objective of our study was to develop and validate the Munich Ankle Questionnaire (MAQ) as a universal self-assessment score including subjective and objective items. The established McGuire Score, Bray Score, Ankle Hindfoot Score (AOFAS) and Olerud and Molander Score were analyzed for relevant items and subscales. Items of interest were then condensed and allocated to the respective subscales of the MAQ. The final MAQ consists of 6 items addressing general and demographic data and 12 items addressing three domains: pain (3 items), work and daily living (5 items), movement and ROM (4 items). The evaluation of validity, reliability and responsiveness of the MAQ was performed in a prospective clinical study including traumatic as well as degenerative ankle pathologies. In total, 148 patients (79 female, 69 male, median age 45 years) were included in the validation study. With intra-class correlation coefficients of at least 0.77, test–retest reliability was proven. Construct validity with a correlation coefficient of 0.82 and responsiveness with a correlation coefficient ranging from 0.42 to 0.47 were confirmed. The MAQ is a reliable and valid self-assessment measurement tool for the follow-up examination regarding subjective and objective parameters of traumatic and degenerative ankle pathologies. The MAQ has no limitation to specific disorders and allows a broad application.