Dieter Wirtz

Prof. Dr. Dieter Wirtz

orcid

Research Focus & Metrics

Academic Career Length

21Years (2006-Present)

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

Representative Publications

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19 May 2020 in Journal of Bone and Joint Surgery
Verified
Journal Article
Closed access
HHHenryk Haffer
Henryk Haffer
FSFriederike Schömig
Friederike Schömig
MRMarkus Rickert
Markus Rickert
Thomas RandauThomas Randau
Thomas Randau
MRMichael Johannes Raschke
Michael Johannes Raschke
CPCarsten Perka
Carsten Perka
Background: The purpose of the present study was to assess the impact of the coronavirus disease 2019 (COVID-19) pandemic on orthopaedic and trauma surgery departments in university hospitals in Germany in order to clarify current challenges. Methods: In this cross-sectional study, an online-based anonymous survey was conducted within the Convention of University Professors of Orthopaedic and Trauma Surgery in Germany from April 3 to April 11, 2020. A bipolar 5-point Likert scale (with possible responses of “totally disagree,” “rather disagree,” “neutral,” “rather agree,” and “totally agree”) was applied. Fifty-two (69.3%) of 75 clinic directors participated. Results: Communication and cooperation with the government, hospital administration, and other departments during the COVID-19 pandemic were mainly perceived as appropriate. However, only 7 respondents (13.7%) totally agreed or rather agreed with the statement that the authorities are supporters of orthopaedic and trauma surgery departments. Substantial financial and personnel changes in orthopaedic and trauma surgery departments of university hospitals were reported, resulting in an average reduction of 49.4% in operating room capacity and an expected 29.3% loss of revenue. In addition, 14.7% of physicians were reallocated from orthopaedic and trauma surgery to other care-delivery environments. Conclusions: Our study demonstrated that the COVID-19 pandemic has had a substantial impact on orthopaedic and trauma surgery departments in German university hospitals. Distinct structural and financial effects were noted. Nevertheless, the present study demonstrates the commitment of our specialty to overcome the pandemic by providing competent personnel as well as close cooperation with the hospital administration and other departments. Clinical Relevance: To our knowledge, this is the first Germany-wide survey among the heads of orthopaedic and trauma surgery departments in university hospitals on the impact of the COVID-19 pandemic. The survey results may help to inform system-wide decision-making in Germany, in Europe, and beyond.

1 May 2017 in Nanomedicine: Nanotechnology, Biology and Medicine
Verified
Journal Article
Closed access
JHJosefine Hirschfeld
Josefine Hirschfeld
EAEser M. Akinoglu
Eser M. Akinoglu
DWDieter Wirtz
Dieter Wirtz
AHAchim Hoerauf
Achim Hoerauf
Isabelle Bekeredjian-DingIsabelle Bekeredjian-Ding
Isabelle Bekeredjian-Ding
MGMichael Giersig
Michael Giersig

1 September 2014 in Acta Orthopaedica
Verified
Journal Article
Open access
DWDieter Wirtz
Dieter Wirtz
SGSascha Gravius
Sascha Gravius
RARudolf Ascherl
Rudolf Ascherl
MTMiguel Thorweihe
Miguel Thorweihe
RFRaimund Forst
Raimund Forst
MDMoritz C Deml
Moritz C Deml
Due to the relative lack of reports on the medium- to long-term clinical and radiographic results of modular femoral cementless revision, we conducted this study to evaluate the medium- to long-term results of uncemented femoral stem revisions using the modular MRP-TITAN stem with distal diaphyseal fixation in a consecutive patient series. We retrospectively analyzed 163 femoral stem revisions performed between 1993 and 2001 with a mean follow-up of 10 (5-16) years. Clinical assessment included the Harris hip score (HHS) with reference to comorbidities and femoral defect sizes classified by Charnley and Paprosky. Intraoperative and postoperative complications were analyzed and the failure rate of the MRP stem for any reason was examined. Mean HHS improved up to the last follow-up (37 (SD 24) vs. 79 (SD 19); p<0.001). 99 cases (61%) had extensive bone defects (Paprosky IIB-III). Radiographic evaluation showed stable stem anchorage in 151 cases (93%) at the last follow-up. 10 implants (6%) failed for various reasons. Neither a breakage of a stem nor loosening of the morse taper junction was recorded. Kaplan-Meier survival analysis revealed a 10-year survival probability of 97% (95% CI: 95-100). This is one of the largest medium- to long-term analyses of cementless modular revision stems with distal diaphyseal anchorage. The modular MRP-TITAN was reliable, with a Kaplan-Meier survival probability of 97% at 10 years.

11 January 2013 in BMC Musculoskeletal Disorders
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Journal Article
Open access
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MWMatthias D Wimmer
Matthias D Wimmer
Thomas RandauThomas Randau
Thomas Randau
MDMoritz C Deml
Moritz C Deml
RARudolf Ascherl
Rudolf Ascherl
UNUlrich Nöth
Ulrich Nöth
SGSascha Gravius
Sascha Gravius
Background: We present a descriptive and retrospective analysis of revision total hip arthroplasties (THA) using the MRP-TITAN stem (Peter Brehm, Weisendorf, GER) with distal diaphyseal fixation and metaphyseal defect augmentation. Our hypothesis was that the metaphyseal defect augmentation (Impaction Bone Grafting) improves the stem survival.Methods: We retrospectively analyzed the aggregated and anonymized data of 243 femoral stem revisions. 68 patients with 70 implants (28.8%) received an allograft augmentation for metaphyseal defects; 165 patients with 173 implants (71.2%) did not, and served as controls. The mean follow-up was 4.4 ± 1.8 years (range, 2.1–9.6 years). There were no significant differences (p > 0.05) between the study and control group regarding age, body mass index (BMI), femoral defects (types I-III as described by Paprosky), and preoperative Harris Hip Score (HHS). Postoperative clinical function was evaluated using the HHS. Postoperative radiologic examination evaluated implant stability, axial implant migration, signs of implant loosening, periprosthetic radiolucencies, as well as bone regeneration and resorption.Results: There were comparable rates of intraoperative and postoperative complications in the study and control groups (p > 0.05). Clinical function, expressed as the increase in the postoperative HHS over the preoperative score, showed significantly greater improvement in the group with Impaction Bone Grafting (35.6 ± 14.3 vs. 30.8 ± 15.8; p ≤ 0.05). The study group showed better outcome especially for larger defects (types II C and III as described by Paprosky) and stem diameters ≥ 17 mm. The two groups did not show significant differences in the rate of aseptic loosening (1.4% vs. 2.9%) and the rate of revisions (8.6% vs. 11%). The Kaplan-Meier survival for the MRP-TITAN stem in both groups together was 93.8% after 8.8 years. [Study group 95.7% after 8.54 years ; control group 93.1% after 8.7 years]. Radiologic evaluation showed no significant change in axial implant migration (4.3% vs. 9.3%; p = 0.19) but a significant reduction in proximal stress shielding (5.7% vs. 17.9%; p < 0.05) in the study group. Periprosthetic radiolucencies were detected in 5.7% of the study group and in 9.8% of the control group (p = 0.30). Radiolucencies in the proximal zones 1 and 7 according to Gruen occurred significantly more often in the control group without allograft augmentation (p ≤ 0.05).Conclusion: We present the largest analysis of the impaction grafting technique in combination with cementless distal diaphyseal stem fixation published so far. Our data provides initial evidence of improved bone regeneration after graft augmentation of metaphyseal bone defects. The data suggests that proximal metaphyseal graft augmentation is beneficial for large metaphyseal bone defects (Paprosky types IIC and III) and stem diameters of 17 mm and above. Due to the limitations of a retrospective and descriptive study the level of evidence remains low and prospective trials should be conducted.

Verified
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RORobert Ossendorff
Robert Ossendorff
AMAlessandra Menon
Alessandra Menon
Frank A. SchildbergFrank A. Schildberg
Frank A. Schildberg
PRPietro Randelli
Pietro Randelli
Sebastian ScheidtSebastian Scheidt
Sebastian Scheidt
DCDavide Cucchi
Davide Cucchi
The biological enhancement of tissue regeneration and healing is an appealing perspective in orthopedics. We aimed to conduct a systematic review to describe the global distribution of studies investigating the use of adipose tissue derivates in orthopedics and to provide information on their quality and on the products available. The quality of the included studies was assessed using the modified Coleman Methodology Score (mCMS) and the Cochrane risk-of-bias tool for randomized trials. Eighty-two studies were included, with a total of 3594 patients treated. In total, 70% of the studies investigated the treatment of knee disorders, predominantly osteoarthritis; 26% of all studies dealt with expanded adipose-derived stem/stromal cells (ADSCs), 72% of which had stromal vascular fraction (SVF); 70% described the injection of adipose tissue derivates into the affected site; and 24% described arthroscopies with the addition of adipose tissue derivates. The mean mCMS for all studies was 51.7 ± 21.4 points, with a significantly higher score for the studies dealing with expanded ADSCs compared to those dealing with SVF (p = 0.0027). Our analysis shows high heterogeneity in terms of the types of performed procedures as well as the choice and processing of adipose tissue derivates.

Verified
Journal Article
Open access
PDF file
SWSebastian Walter
Sebastian Walter
Thomas RandauThomas Randau
Thomas Randau
CHCäcilia Hilgers
Cäcilia Hilgers
EHEl-Mustapha Haddouti
El-Mustapha Haddouti
WMWerner Masson
Werner Masson
Frank A. SchildbergFrank A. Schildberg
Frank A. Schildberg
Mesenchymal stromal cells (MSC) harvested in different tissues from the same donor exhibit different phenotypes. Each phenotype is not only characterized by a certain pattern of cell surface markers, but also different cellular functionalities. Only recently were different harvesting and processing techniques found to contribute to this phenomenon as well. This study was therefore set up to investigate proteomic and functional properties of human bone marrow-derived MSCs (hBM-MSC). These were taken from the same tissue and donor site but harvested either as aspirate or bone chip cultures. Both MSC populations were profiled for MSC markers defined by the International Society for Cellular Therapy (ISCT), MSC markers currently under discussion and markers of particular interest. While classic ISCT MSC markers did not show any significant difference between aspirate and outgrowth hBM-MSCs, our additional characterization panel revealed distinct patterns of differentially expressed markers. Furthermore, hBM-MSCs from aspirate cultures demonstrated a significantly higher osteogenic differentiation potential than outgrowth MSCs, which could be confirmed using a transcriptional approach. Our comparison of MSC phenotypes obtained by different harvesting techniques suggests the need of future standardized harvesting, processing and phenotyping procedures in order to gain better comparability in the MSC field.