Siegmund Lang

Dr. Siegmund Lang

Department for Trauma Surgery, University Hospital Regensburg, Regensburg, Bavaria, Germany
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Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

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

Representative Publications

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25 January 2019 in JOR SPINE
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MLMarkus Loibl
Markus Loibl
Karin Wuertz-KozakKarin Wuertz-Kozak
Karin Wuertz-Kozak
Gianluca VadalàGianluca Vadalà
Gianluca Vadalà
Siegmund LangSiegmund Lang
Siegmund Lang
JFJeremy Fairbank
Jeremy Fairbank
JUJill P. Urban
Jill P. Urban
Low back pain (LBP) can significantly reduce the quality of life of patients, and has a considerable economic and social impact worldwide. It is commonly associated with disc degeneration, even though many people with degenerate discs are asymptomatic. Degenerate disc disease (DDD), is thus a common term for intervertebral disc (IVD) degeneration associated with LBP. Degeneration is thought to lead to LBP because of nerve ingrowth into the degenerate disc, inflammation, or because degradation of extracellular matrix (ECM) alters spinal biomechanics inappropriately. Thus, while the objectives of some interventions for LBP are to control pain intensity, other interventions aim to deal with the consequences of disc degeneration through stabilizing the disc surgically, by inserting artificial discs or by repairing the disc biologically and preventing progressive IVD degeneration. Despite tremendous research efforts, treatment of LBP through the use of regenerative interventions aiming to repair the IVD is still controversial. The use of mesenchymal stem cells for IVD regeneration in a patient‐based case will be discussed by an ensemble of clinicians and researchers.

21 September 2018 in European Surgical Research
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Siegmund LangSiegmund Lang
Siegmund Lang
MLMarkus Loibl
Markus Loibl
MHMarietta Herrmann
Marietta Herrmann
Background: Platelet-rich plasma (PRP) refers to an enriched platelet suspension in plasma. In addition to the clinical application of PRP in the context of various orthopedic diseases and beyond, PRP and platelet lysate (PL) have been in focus in the field of tissue engineering. In this review, we discuss the application of PRP as a cell culture supplement and as part of tissue engineering strategies, particularly emphasizing current hurdles and ambiguities regarding the efficacy of PRP in these approaches. Summary: As a putative autologous replacement for animal-derived supplements such as fetal calf serum (FCS), PRP has been applied as cell culture supplement for the expansion of stem and progenitor cells for tissue engineering applications and cell therapies. Attributed to the high content of growth factors in platelets, PRP has been shown to promote cell growth, which was mostly superior to standard cultures supplemented with FCS, while the differentiation capacity of progenitor cells seems not to be affected. However, it was also suggested that cultivation of cells with PRP significantly alters the protein expression profile in cells in comparison to FCS, indicating that the influence of PRP on cell behavior should be thoroughly investigated. Moreover, different PRP preparation methods and donor variations have to be considered for the use of PRP under good manufacturing practice conditions. PRP has been used for various tissue engineering applications in the context of bone, cartilage, skin, and soft tissue repair, where most studies were conducted in the field of bone tissue engineering. These approaches take either advantage of the release of chemoattractive, angiogenic, proliferative, and putatively pro-regenerative growth factors from PRP, and/or the hydrogel properties of activated PRP, making it suitable as a cell delivery vehicle. In many of these studies, PRP is combined with biomaterials, cells, and in some cases recombinant growth factors. Although the experimental design often does not allow conclusions on the pro-regenerative effect of PRP itself, most publications report beneficial effects if PRP is added to the tissue-engineered construct. Furthermore, it was demonstrated that the release of growth factors from PRP may be tailored and controlled when PRP is combined with materials able to capture growth factors. Key Messages: Platelet-derived preparations such as PRP and PL represent a promising source of autologous growth factors, which may be applied as cell culture supplement or to promote regeneration in tissue-engineered constructs. Furthermore, activated PRP is a promising candidate as an autologous cell carrier. However, the studies investigating PRP in these contexts often show conflicting results, which most likely can be attributed to the lack of standardized preparation methods, particularly with regard to the platelet content and donor variation of PRP. Ultimately, the use of PRP has to be tailored for the individual application.

17 May 2021 in Scientific Reports
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NWNike Walter
Nike Walter
MRMarkus Rupp
Markus Rupp
Siegmund LangSiegmund Lang
Siegmund Lang
VAVolker Alt
Volker Alt
The epidemiology of fracture-related infection (FRI) is unknown, which makes it difficult to estimate future demands and evaluate progress in infection prevention. Therefore, we aimed to determine the nationwide burden’s development over the last decade as a function of age group and gender. FRI prevalence as a function of age group and gender was quantified based on annual ICD-10 diagnosis codes from German medical institutions between 2008 through 2018, provided by the Federal Statistical Office of Germany (Destatis). The prevalence of FRI increased by 0.28 from 8.4 cases per 100,000 inhabitants to 10.7 cases per 100,000 inhabitants between 2008 and 2018. The proportion of fractures resulting in FRI increased from 1.05 to 1.23%. Gender distribution was equal. Patients aged 60–69 years and 70–79 years comprised the largest internal proportion with 20.2% and 20.7%, respectively, whereby prevalence increased with age group. A trend towards more diagnoses in older patients was observed with a growth rate of 0.63 for patients older than 90 years. Increasing rates of fracture-related infection especially in older patients indicate an upcoming challenge for stakeholders in health care systems. Newly emerging treatment strategies, prevention methods and interdisciplinary approaches are strongly required.

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Siegmund LangSiegmund Lang
Siegmund Lang
NWNike Walter
Nike Walter
MSMelanie Schindler
Melanie Schindler
SBSusanne Baertl
Susanne Baertl
DSDominik Szymski
Dominik Szymski
MRMarkus Rupp
Markus Rupp
Background: Spondylodiscitis can lead to significant morbidity and mortality. Understanding its up-to-date epidemiological characteristics and trends is important to improve patient care. Methods: This study analyzed trends in the incidence rate of spondylodiscitis cases in Germany between 2010 and 2020, as well as the pathogens, in-hospital mortality rate, and length of hospital stay. Data were obtained from the Federal Statistical Office and the Institute for the Hospital Remuneration System database. The ICD-10 codes “M46.2-”, “M46.3-” and “M46.4-” were evaluated. Results: The incidence rate of spondylodiscitis increased to 14.4/100,000 inhabitants, with 59.6% cases occurring in patients 70 years or older and affecting mainly the lumbar spine (56.2%). Absolute case numbers increased from 6886 by 41.6% to 9753 in 2020 (IIR = 1.39, 95% CI 0.62–3.08). Staphylococci and Escherichia coli were the most coded pathogens. The proportion of resistant pathogens was 12.9%. In-hospital mortality rates increased to a maximum of 64.7/1000 patients in 2020, intensive care unit treatment was documented in 2697 (27.7%) cases, and the length of stay per case was 22.3 days. Conclusion: The sharply increasing incidence and in-hospital mortality rate of spondylodiscitis highlights the need for patient-centered therapy to improve patient outcomes, especially in the geriatric, frail population, which is prone to infectious diseases.

10 October 2017 in Stem Cell Research & Therapy
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JZJohannes Zellner
Johannes Zellner
GPGirish Pattappa
Girish Pattappa
MKMatthias Koch
Matthias Koch
Siegmund LangSiegmund Lang
Siegmund Lang
JWJohannes Weber
Johannes Weber
PAPeter Angele
Peter Angele
Treatment of meniscus tears within the avascular region represents a significant challenge, particularly in a situation of early osteoarthritis. Cell-based tissue engineering approaches have shown promising results. However, studies have not found a consensus on the appropriate autologous cell source in a clinical situation, specifically in a challenging degenerative environment. The present study sought to evaluate the appropriate cell source for autologous meniscal repair in a demanding setting of early osteoarthritis. A rabbit model was used to test autologous meniscal repair. Bone marrow and medial menisci were harvested 4 weeks prior to surgery. Bone marrow-derived mesenchymal stem cells (MSCs) and meniscal cells were isolated, expanded, and seeded onto collagen-hyaluronan scaffolds before implantation. A punch defect model was performed on the lateral meniscus and then a cell-seeded scaffold was press-fit into the defect. Following 6 or 12 weeks, gross joint morphology and OARSI grade were assessed, and menisci were harvested for macroscopic, histological, and immunohistochemical evaluation using a validated meniscus scoring system. In conjunction, human meniscal cells isolated from non-repairable bucket handle tears and human MSCs were expanded and, using the pellet culture model, assessed for their meniscus-like potential in a translational setting through collagen type I and II immunostaining, collagen type II enzyme-linked immunosorbent assay (ELISA), and gene expression analysis. After resections of the medial menisci, all knees showed early osteoarthritic changes (average OARSI grade 3.1). However, successful repair of meniscus punch defects was performed using either meniscal cells or MSCs. Gross joint assessment demonstrated donor site morbidity for meniscal cell treatment. Furthermore, human MSCs had significantly increased collagen type II gene expression and production compared to meniscal cells (p < 0.05). The regenerative potential of the meniscus by an autologous cell-based tissue engineering approach was shown even in a challenging setting of early osteoarthritis. Autologous MSCs and meniscal cells were found to have improved meniscal healing in an animal model, thus demonstrating their feasibility in a clinical setting. However, donor site morbidity, reduced availability, and reduced chondrogenic differentiation of human meniscal cells from debris of meniscal tears favors autologous MSCs for clinical use for cell-based meniscus regeneration.

28 April 2023 in Scientific Reports
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Siegmund LangSiegmund Lang
Siegmund Lang
NWNike Walter
Nike Walter
VFViola Freigang
Viola Freigang
CNCarsten Neumann
Carsten Neumann
MLMarkus Loibl
Markus Loibl
MRMarkus Rupp
Markus Rupp
The aim of this cross-sectional study was to present the nationwide rates of hospitalized patients with vertebral fractures over one decade and to comprehensively analyze the treatment characteristics and direct costs incurred in 2019. Therefore, the trends in the incidence rate were quantified based on annual ICD-10 diagnosis codes from all German medical facilities between 2009 and 2019, provided by the Federal Statistical Office (Destatis). The ICD-10 Codes “S12.0-2; S22.0-; S32.0-, and S32.1-2” were evaluated. The relative change from 2009 through 2019 was determined. Using data from the Institute for Hospital Remuneration Systems (InEK) for 2019 the secondary diagnoses, OPS-codes, intensive care unit (ICU) treatment, in-hospital mortality, the proportion of G-DRGs and cumulative costs were evaluated. The documented number of vertebral fractures increased by 45.6% between 2009 and 2019 to an incidence of 150.7 per 100,000 inhabitants. The lumbar spine was most commonly affected with an incidence of 70.5/100,000 inhabitants in 2019 (46.8% of all vertebral fractures). The highest increases were seen in the numbers of subaxial cervical fractures (+ 121.2%) and sacral fractures (+ 306.6%). Of all vertebral fractures in 2019, 63.7% were diagnosed in women and 69.0% in patients aged 70 years or older. Osteoporosis was documented in 17.9% of cases as a concomitant diagnosis. In 10.1% of all cases, an ICU treatment was documented. The in-hospital mortality was 2.0% in 2019. I68D was the most frequently used G-DRG code, accounting for 33.3% of cases. The total direct costs for inpatient treatment in 2019 amounted to €589,205,715. The evaluation of 955,091 vertebral fractures showed a sharp increase in the nation-wide incidence rate. The presented age and sex distribution, the comorbidity profile and the in-hospital mortality rate indicate the importance of comprehensive geriatric assessment and emphasize the need for spinal care centers to be established.