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One of the most fundamental questions in ecology is how many species inhabit the Earth. However, due to massive logistical and financial challenges and taxonomic difficulties connected to the species concept definition, the global numbers of species, including those of important and well-studied life forms such as trees, still remain largely unknown. Here, based on global ground-sourced data, we estimate the total tree species richness at global, continental, and biome levels. Our results indicate that there are ∼73,000 tree species globally, among which ∼9,000 tree species are yet to be discovered. Roughly 40% of undiscovered tree species are in South America. Moreover, almost one-third of all tree species to be discovered may be rare, with very low populations and limited spatial distribution (likely in remote tropical lowlands and mountains). These findings highlight the vulnerability of global forest biodiversity to anthropogenic changes in land use and climate, which disproportionately threaten rare species and thus, global tree richness., Proceedings of the National Academy of Sciences of the United States of America, 119 (6), ISSN:0027-8424, ISSN:1091-6490 more...

The latitudinal diversity gradient (LDG) is one of the most recognized global patterns of species richness exhibited across a wide range of taxa. Numerous hypotheses have been proposed in the past two centuries to explain LDG, but rigorous tests of the drivers of LDGs have been limited by a lack of high-quality global species richness data. Here we produce a high-resolution (0.025° × 0.025°) map of local tree species richness using a global forest inventory database with individual tree information and local biophysical characteristics from ~1.3 million sample plots. We then quantify drivers of local tree species richness patterns across latitudes. Generally, annual mean temperature was a dominant predictor of tree species richness, which is most consistent with the metabolic theory of biodiversity (MTB). However, MTB underestimated LDG in the tropics, where high species richness was also moderated by topographic, soil and anthropogenic factors operating at local scales. Given that local landscape variables operate synergistically with bioclimatic factors in shaping the global LDG pattern, we suggest that MTB be extended to account for co-limitation by subordinate drivers. The team collaboration and manuscript development are supported by the web-based team science platform: science-i.org, with the project number 202205GFB2. We thank the following initiatives, agencies, teams and individuals for data collection and other technical support: the Global Forest Biodiversity Initiative (GFBI) for establishing the data standards and collaborative framework; United States Department of Agriculture, Forest Service, Forest Inventory and Analysis (FIA) Program; University of Alaska Fairbanks; the SODEFOR, Ivory Coast; University Félix Houphouët-Boigny (UFHB, Ivory Coast); the Queensland Herbarium and past Queensland Government Forestry and Natural Resource Management departments and staff for data collection for over seven decades; and the National Forestry Commission of Mexico (CONAFOR). We thank M. Baker (Carbon Tanzania), together with a team of field assistants (Valentine and Lawrence); all persons who made the Third Spanish Forest Inventory possible, especially the main coordinator, J. A. Villanueva (IFN3); the French National Forest Inventory (NFI campaigns (raw data 2005 and following annual surveys, were downloaded by GFBI at https://inventaire-forestier.ign.fr/spip.php?rubrique159; site accessed on 1 January 2015)); the Italian Forest Inventory (NFI campaigns raw data 2005 and following surveys were downloaded by GFBI at https://inventarioforestale.org/; site accessed on 27 April 2019); Swiss National Forest Inventory, Swiss Federal Institute for Forest, Snow and Landscape Research WSL and Federal Office for the Environment FOEN, Switzerland; the Swedish NFI, Department of Forest Resource Management, Swedish University of Agricultural Sciences SLU; the National Research Foundation (NRF) of South Africa (89967 and 109244) and the South African Research Chair Initiative; the Danish National Forestry, Department of Geosciences and Natural Resource Management, UCPH; Coordination for the Improvement of Higher Education Personnel of Brazil (CAPES, grant number 88881.064976/2014-01); R. Ávila and S. van Tuylen, Instituto Nacional de Bosques (INAB), Guatemala, for facilitating Guatemalan data; the National Focal Center for Forest condition monitoring of Serbia (NFC), Institute of Forestry, Belgrade, Serbia; the Thünen Institute of Forest Ecosystems (Germany) for providing National Forest Inventory data; the FAO and the United Nations High Commissioner for Refugees (UNHCR) for undertaking the SAFE (Safe Access to Fuel and Energy) and CBIT-Forest projects; and the Amazon Forest Inventory Network (RAINFOR), the African Tropical Rainforest Observation Network (AfriTRON) and the ForestPlots.net initiative for their contributions from Amazonian and African forests. The Natural Forest plot data collected between January 2009 and March 2014 by the LUCAS programme for the New Zealand Ministry for the Environment are provided by the New Zealand National Vegetation Survey Databank https://nvs.landcareresearch.co.nz/. We thank the International Boreal Forest Research Association (IBFRA); the Forestry Corporation of New South Wales, Australia; the National Forest Directory of the Ministry of Environment and Sustainable Development of the Argentine Republic (MAyDS) for the plot data of the Second National Forest Inventory (INBN2); the National Forestry Authority and Ministry of Water and Environment of Uganda for their National Biomass Survey (NBS) dataset; and the Sabah Biodiversity Council and the staff from Sabah Forest Research Centre. All TEAM data are provided by the Tropical Ecology Assessment and Monitoring (TEAM) Network, a collaboration between Conservation International, the Missouri Botanical Garden, the Smithsonian Institution and the Wildlife Conservation Society, and partially funded by these institutions, the Gordon and Betty Moore Foundation and other donors, with thanks to all current and previous TEAM site manager and other collaborators that helped collect data. We thank the people of the Redidoti, Pierrekondre and Cassipora village who were instrumental in assisting with the collection of data and sharing local knowledge of their forest and the dedicated members of the field crew of Kabo 2012 census. We are also thankful to FAPESC, SFB, FAO and IMA/SC for supporting the IFFSC. This research was supported in part through computational resources provided by Information Technology at Purdue, West Lafayette, Indiana.This work is supported in part by the NASA grant number 12000401 ‘Multi-sensor biodiversity framework developed from bioacoustic and space based sensor platforms’ (J. Liang, B.P.); the USDA National Institute of Food and Agriculture McIntire Stennis projects 1017711 (J. Liang) and 1016676 (M.Z.); the US National Science Foundation Biological Integration Institutes grant NSF‐DBI‐2021898 (P.B.R.); the funding by H2020 VERIFY (contract 776810) and H2020 Resonate (contract 101000574) (G.-J.N.); the TEAM project in Uganda supported by the Moore foundation and Buffett Foundation through Conservation International (CI) and Wildlife Conservation Society (WCS); the Danish Council for Independent Research | Natural Sciences (TREECHANGE, grant 6108- 00078B) and VILLUM FONDEN grant number 16549 (J.-C.S.); the Natural Environment Research Council of the UK (NERC) project NE/T011084/1 awarded to J.A.-G. and NE/S011811/1; ERC Advanced Grant 291585 (‘T-FORCES’) and a Royal Society-Wolfson Research Merit Award (O.L.P.); RAINFOR plots supported by the Gordon and Betty Moore Foundation and the UK Natural Environment Research Council, notably NERC Consortium Grants ‘AMAZONICA’ (NE/F005806/1), ‘TROBIT’ (NE/D005590/1) and ‘BIO-RED’ (NE/N012542/1); CIFOR’s Global Comparative Study on REDD+ funded by the Norwegian Agency for Development Cooperation, the Australian Department of Foreign Affairs and Trade, the European Union, the International Climate Initiative (IKI) of the German Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety and the CGIAR Research Program on Forests, Trees and Agroforestry (CRP-FTA) and donors to the CGIAR Fund; AfriTRON network plots funded by the local communities and NERC, ERC, European Union, Royal Society and Leverhume Trust; a grant from the Royal Society and the Natural Environment Research Council, UK (S.L.L.); National Science Foundation CIF21 DIBBs: EI: number 1724728 (A.C.C.); National Natural Science Foundation of China (31800374) and Shandong Provincial Natural Science Foundation (ZR2019BC083) (H.L.). UK NERC Independent Research Fellowship (grant code: NE/S01537X/1) (T.J.); a Serra-Húnter Fellowship provided by the Government of Catalonia (Spain) (S.d.-M.); the Brazilian National Council for Scientific and Technological Development (CNPq, grant 442640/2018-8, CNPq/Prevfogo-Ibama number 33/2018) (C.A.S.); a grant from the Franklinia Foundation (D.A.C.); Russian Science Foundation project number 19-77-300-12 (R.V.); the Takenaka Scholarship Foundation (A.O.A.); the German Research Foundation (DFG), grant number Am 149/16-4 (C.A.); the Romania National Council for Higher Education Funding, CNFIS, project number CNFIS-FDI-2022-0259 (O.B.); Natural Sciences and Engineering Research Council of Canada (RGPIN-2019-05109 and STPGP506284) and the Canadian Foundation for Innovation (36014) (H.Y.H.C.); the project SustES—Adaptation strategies for sustainable ecosystem services and food security under adverse environmental conditions (CZ.02.1.01/0.0/0.0/16_019/0000797) (E.C.); Consejo de Ciencia y Tecnología del estado de Durango (2019-01-155) (J.J.C.-R.); Science and Engineering Research Board (SERB), New Delhi, Government of India (file number PDF/2015/000447)— ‘Assessing the carbon sequestration potential of different forest types in Central India in response to climate change’ (J.A.D.); Investissement d’avenir grant of the ANR (CEBA: ANR-10-LABEX-0025) (G.D.); National Foundation for Science & Technology Development of Vietnam, 106-NN.06-2013.01 (T.V.D.); Queensland government, Department of Environment and Science (T.J.E.); a Czech Science Foundation Standard grant (19-14620S) (T.M.F.); European Union Seventh Framework Program (FP7/2007– 2013) under grant agreement number 265171 (L. Finer, M. Pollastrini, F. Selvi); grants from the Swedish National Forest Inventory, Swedish University of Agricultural Sciences (J.F.); CNPq productivity grant number 311303/2020-0 (A.L.d.G.); DFG grant HE 2719/11-1,2,3; HE 2719/14-1 (A. Hemp); European Union’s Horizon Europe research project OpenEarthMonitor grant number 101059548, CGIAR Fund INIT-32-MItigation and Transformation Initiative for GHG reductions of Agrifood systems RelaTed Emissions (MITIGATE+) (M.H.); General Directorate of the State Forests, Poland (1/07; OR-2717/3/11; OR.271.3.3.2017) and the National Centre for Research and Development, Poland (BIOSTRATEG1/267755/4/NCBR/2015) (A.M.J.); Czech Science Foundation 18-10781 S (S.J.); Danish of Ministry of Environment, the Danish Environmental Protection Agency, Integrated Forest Monitoring Program—NFI (V.K.J.); State of São Paulo Research Foundation/FAPESP as part of the BIOTA/FAPESP Program Project Functional Gradient-PELD/BIOTA-ECOFOR 2003/12595-7 & 2012/51872-5 (C.A.J.); Danish Council for Independent Research—social sciences—grant DFF 6109– 00296 (G.A.K.); Russian Science Foundation project 21-46-07002 for the plot data collected in the Krasnoyarsk region (V.K.); BOLFOR (D.K.K.); Department of Biotechnology, New Delhi, Government of India (grant number BT/PR7928/ NDB/52/9/2006, dated 29 September 2006) (M.L.K.); grant from Kenya Coastal Development Project (KCDP), which was funded by World Bank (J.N.K.); Korea Forest Service (2018113A00-1820-BB01, 2013069A00-1819-AA03, and 2020185D10- 2022-AA02) and Seoul National University Big Data Institute through the Data Science Research Project 2016 (H.S.K.); the Brazilian National Council for Scientific and Technological Development (CNPq, grant 442640/2018-8, CNPq/Prevfogo-Ibama number 33/2018) (C.K.); CSIR, New Delhi, government of India (grant number 38(1318)12/EMR-II, dated: 3 April 2012) (S.K.); Department of Biotechnology, New Delhi, government of India (grant number BT/ PR12899/ NDB/39/506/2015 dated 20 June 2017) (A.K.); Coordination for the Improvement of Higher Education Personnel (CAPES) #88887.463733/2019-00 (R.V.L.); National Natural Science Foundation of China (31800374) (H.L.); project of CEPF RAS ‘Methodological approaches to assessing the structural organization and functioning of forest ecosystems’ (AAAA-A18-118052590019-7) funded by the Ministry of Science and Higher Education of Russia (N.V.L.); Leverhulme Trust grant to Andrew Balmford, Simon Lewis and Jon Lovett (A.R.M.); Russian Science Foundation, project 19-77-30015 for European Russia data processing (O.M.); grant from Kenya Coastal Development Project (KCDP), which was funded by World Bank (M.T.E.M.); the National Centre for Research and Development, Poland (BIOSTRATEG1/267755/4/NCBR/2015) (S.M.); the Secretariat for Universities and of the Ministry of Business and Knowledge of the Government of Catalonia and the European Social Fund (A. Morera); Queensland government, Department of Environment and Science (V.J.N.); Pinnacle Group Cameroon PLC (L.N.N.); Queensland government, Department of Environment and Science (M.R.N.); the Natural Sciences and Engineering Research Council of Canada (RGPIN-2018-05201) (A.P.); the Russian Foundation for Basic Research, project number 20-05-00540 (E.I.P.); European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement number 778322 (H.P.); Science and Engineering Research Board, New Delhi, government of India (grant number YSS/2015/000479, dated 12 January 2016) (P.S.); the Chilean Government research grants Fondecyt number 1191816 and FONDEF number ID19 10421 (C.S.-E.); the Deutsche Forschungsgemeinschaft (DFG) Priority Program 1374 Biodiversity Exploratories (P.S.); European Space Agency projects IFBN (4000114425/15/NL/FF/gp) and CCI Biomass (4000123662/18/I-NB) (D. Schepaschenko); FunDivEUROPE, European Union Seventh Framework Programme (FP7/2007–2013) under grant agreement number 265171 (M.S.-L.); APVV 20-0168 from the Slovak Research and Development Agency (V.S.); Manchester Metropolitan University’s Environmental Science Research Centre (G.S.); the project ‘LIFE+ ForBioSensing PL Comprehensive monitoring of stand dynamics in Białowieża Forest supported with remote sensing techniques’ which is co-funded by the EU Life Plus programme (contract number LIFE13 ENV/PL/000048) and the National Fund for Environmental Protection and Water Management in Poland (contract number 485/2014/WN10/OP-NM-LF/D) (K.J.S.); Global Challenges Research Fund (QR allocation, MMU) (M.J.P.S.); Czech Science Foundation project 21-27454S (M.S.); the Russian Foundation for Basic Research, project number 20-05-00540 (N. Tchebakova); Botanical Research Fund, Coalbourn Trust, Bentham Moxon Trust, Emily Holmes scholarship (L.A.T.); the programmes of the current scientific research of the Botanical Garden of the Ural Branch of Russian Academy of Sciences (V.A.U.); FCT—Portuguese Foundation for Science and Technology—Project UIDB/04033/2020. Inventário Florestal Nacional—ICNF (H. Viana); Grant from Kenya Coastal Development Project (KCDP), which was funded by World Bank (C.W.); grants from the Swedish National Forest Inventory, Swedish University of Agricultural Sciences (B.W.); ATTO project (grant number MCTI-FINEP 1759/10 and BMBF 01LB1001A, 01LK1602F) (F.W.); ReVaTene/ PReSeD-CI 2 is funded by the Education and Research Ministry of Côte d’Ivoire, as part of the Debt Reduction-Development Contracts (C2Ds) managed by IRD (I.C.Z.-B.); the National Research Foundation of South Africa (NRF, grant 89967) (C.H.). The Tropical Plant Exploration Group 70 1 ha plots in Continental Cameroon Mountains are supported by Rufford Small Grant Foundation, UK and 4 ha in Sierra Leone are supported by the Global Challenge Research Fund through Manchester Metropolitan University, UK; the National Geographic Explorer Grant, NGS-53344R-18 (A.C.-S.); University of KwaZulu-Natal Research Office grant (M.J.L.); Universidad Nacional Autónoma de México, Dirección General de Asuntos de Personal Académico, Grant PAPIIT IN-217620 (J.A.M.). Czech Science Foundation project 21-24186M (R.T., S. Delabye). Czech Science Foundation project 20-05840Y, the Czech Ministry of Education, Youth and Sports (LTAUSA19137) and the long-term research development project of the Czech Academy of Sciences no. RVO 67985939 (J.A.). The American Society of Primatologists, the Duke University Graduate School, the L.S.B. Leakey Foundation, the National Science Foundation (grant number 0452995) and the Wenner-Gren Foundation for Anthropological Research (grant number 7330) (M.B.). Research grants from Conselho Nacional de Desenvolvimento Científico e Tecnologico (CNPq, Brazil) (309764/2019; 311303/2020) (A.C.V., A.L.G.). The Project of Sanya Yazhou Bay Science and Technology City (grant number CKJ-JYRC-2022-83) (H.-F.W.). The Ugandan NBS was supported with funds from the Forest Carbon Partnership Facility (FCPF), the Austrian Development Agency (ADC) and FAO. FAO’s UN-REDD Program, together with the project on ‘Native Forests and Community’ Loan BIRF number 8493-AR UNDP ARG/15/004 and the National Program for the Protection of Native Forests under UNDP funded Argentina’s INBN2. more...

Objectives: The goal of this study is to investigate the biomechanical and histological properties of in vivo heterotopically prefabricated quadriceps tendon grafts with mechanical stimulation. The clinical goal is to heterotopically prefabricate a bone-tendon-bone graft as a viable option for ACL reconstruction.[for full text, please go to the a.m. URL], Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2017) more...

ObjectivesThe aims of this study were to determine whether the administration of anti-inflammatory and antifibrotic agents affect the proliferation, viability, and expression of markers involved in the fibrotic development of the fibroblasts obtained from arthrofibrotic tissue in vitro, and to evaluate the effect of the agents on arthrofibrosis prevention in vivo.MethodsDexamethasone, diclofenac, and decorin, in different concentrations, were employed to treat fibroblasts from arthrofibrotic tissue (AFib). Cell proliferation was measured by DNA quantitation, and viability was analyzed by Live/Dead staining. The levels of procollagen type I N-terminal propeptide (PINP) and procollagen type III N-terminal propeptide (PIIINP) were evaluated with enzyme-linked immunosorbent assay (ELISA) kits. In addition, the expressions of fibrotic markers were detected by real-time polymerase chain reaction (PCR). Fibroblasts isolated from healthy tissue (Fib) served as control. Further, a rabbit model of joint contracture was used to evaluate the antifibrotic effect of the three different agents.ResultsDexamethasone maintained the viability and promoted the proliferation of AFib. Diclofenac decreased the viability and inhibited the cell proliferation during the first week of cultivation. However, decorin inhibited AFib proliferation and downregulated the expressions of fibrotic markers. Additionally, decorin could improve the flexion contracture angle and inhibit the deposition of interstitial matrix components in the rabbit joint model.ConclusionDecorin decreased the expression of myofibroblast markers in AFib, inhibited the proliferation of AFib, and prevented the initial procedure of arthrofibrosis in vivo, suggesting that decorin could be a promising treatment to inhibit the development of arthrofibrosis. Cite this article: X. Tang, S. Teng, M. Petri, C. Krettek, C. Liu, M. Jagodzinski. The effect of anti-inflammatory and antifibrotic agents on fibroblasts obtained from arthrofibrotic tissue: An in vitro and in vivo study. Bone Joint Res 2018;7:213–222. DOI: 10.1302/2046-3758.73.BJR-2017-0219.R2. more...

Bei der Prafabrikation von Knochentransplantaten steht im Gegensatz zu Knorpeltransplantaten ab einer kritischen Grose die Vaskularisierung des Transplantats im Vordergrund. Insbesondere gilt dies fur postinfektiose Defekte oder bei einem ersatzschwachen Transplantationslager. Hier konnten in den letzten Jahren klinisch durch die Generierung von Angiogenese am Transplantatort (Masquelet-Technik) oder tierexperimentell durch die In-vivo-Kultivierung eines gefasgestielten Konstrukts, welches dann mittels mikrovaskularer Technik transplantiert werden kann, neue Therapieoptionen untersucht werden. more...

ZusammenfassungTraumatische Gelenkflächendefekte entstehen durch Trauma, Tumor, entzündliche oder degenerative Gelenkerkrankungen und nach der Explantation orthopädischer Implantate. Die Defektdeckung kann bei fehlender Kontraindikation durch autologen oder allogenen Knochen, osteochondrale Transplantate oder vaskularisierte Implantate erfolgen. Eine neue Therapieoption ist bei ausgedehnten Defekten die Implantation maßgefertigter Hybridimplantate aus autologem Knochen und in vitro kultivierten Knorpelzellen. Dieser Artikel gibt einen Überblick über die Pathogenese und die Vor- und Nachteile der verschiedenen Therapieoptionen. more...

ZusammenfassungEtwa 20 Prozent der Klavikulafrakturen betreffen das laterale Drittel. Aufgrund der hier verlaufenden korakoklavikulären (CC) Bänder, der biomechanischen Exposition und der Nähe zum Akromioklavikulargelenk werden diese Frakturen als eigenständige Entität betrachtet. Wenn die CC-Bänder das mediale Fragment nicht mehr stabilisieren, resultiert eine Instabilität der Fraktur mit erheblicher Dislokation des medialen Fragments nach kranial. Die Rationale zur operativen Versorgung der lateralen Klavikulafrakturen ist in der hohen Rate von Pseudarthrosen begründet. Neben den klassischen Osteosyntheseverfahren ist mit dem TightRope®-System (Fa. Arthrex) eine völlig neuartige Therapieoption hinzugekommen. Durch ein korakoklavikuläres Seilzug system wird das mediale Fragment kaudalisiert und die Fraktur somit indirekt reponiert. Die operative Technik und erste Erfahrungen werden dargestellt. more...

AIM The aim of the study was to investigate the effects of dexamethasone and cyclic mechanical strain on human bone marrow stromal cells (hBMSCs) in osteogenic differentiation by determing levels of mRNA of collagen I, II, III, tenascin C and Cbfa1. METHOD hBMSCs from seven donors (32.5 +/- 6.2 years old) were cultivated with (D +) or without (D -) dexamethasone. After the second passage 2.2 x 10 (5) cells were seeded on flexible silicon dishes. A cyclic mechanical strain with an elongation of 2 % (D + 2; D - 2) or 8 % (D + 8; D - 8) was applied for three days with a stimulation time of three times for two hours each day. Cells were harvested on day 1, day 1 after stress (day 4) and day 4 after stress (day 7). mRNA expression of collagen I, II, III, tenascin C and Cbfa1 was investigated by RT-PCR. RESULTS Cbfa1 mRNA levels were significantly different on different days (p < 0.05), and for strain on day 1: 8 %: 0.0291 +/- 0.0338 versus 0 %: 0.00 528 +/- 0.0127, p = 0.017; day 8: 8 %: 0.0411 +/- 0.116, 0 %: 0.00 103 +/- 0.00 217, p = 0.009. All other observed paramaters showed tendencies without significant differences. CONCLUSION In the short-term over seven days, cyclic stretching is a stronger differentiation factor than dexamethasone. more...

This article traces the history of university presses in North America, from the founding of the first presses at Cornell University and Johns Hopkins in the last quarter of the nineteenth century to the present. The growth of colleges and universities and new imperatives that faculty engage in productive research helped shape the function of the modern university press. In the twentieth century, smaller subsidies from parent institutions, new developments in technology, and the erosion of library budgets affected the stability of many presses and forced many to revise both their editorial goals and their business and management practices. Faced with new modes of scholarly communication, the explosion of digital publishing, and the open-access movement, university presses will need to continue to adapt and to assert their proper role in the scholarly community. more...

Die Untersuchung des verletzten Kniegelenks, um die es in diesem Kapitel geht, umfasst die allgemeine Symptomatik und die Prufung der Stabilitat. Letztere kann durch unterschiedliche Tests und Untersuchungen gepruft werden, die die Autoren hier vorstellen. Neben der Seitenstabilitat werden die Messung der Instabilitat und die Prufung der vorderen und hinteren Stabilitat ebenso wie die der Rotationsstabilitat und der Bandstabilitat besprochen. Weiterhin befasst sich das Kapitel mit der Moglichkeit und auch den Grenzen der Rontgendiagnostik zur untersuchenden Darstellung des Knies. more...

In diesem Kapitel stehen die sekundare Rekonstruktion und der plastische Ersatz der Bander bei der frischen oder veralteten Verletzung im Fokus. Dabei werden sowohl konservative Therapieverfahren sowie primare und sekundare Therapieoptionen beleuchtet. Der Kreuzbandersatz und die Rekonstruktion des Zentralpfeilers werden ebenso behandelt, wie der begleitende traumatische Knorpelschaden und seine Behandlung. Ferner wird auf mogliche Komplikationen und allgemeine operationstechnische Hinweise eingegangen. more...

In diesem Kapitel steht die Kinematik und angewandte Physiologie sowie Pathophysiologie der Ligamente im Vordergrund. Hierbei werden vor allem wesentliche kinematische und physiologische Aspekte der Kreuzbander und Kollateralbander sowie das Zusammenspiel der Bandkomponenten untereinander, aber auch mit den anderen Strukturen des Knies und vor allem bei den unterschiedlichen Varianten der Rotation beleuchtet. more...

In diesem Kapitel werden die haufigsten Verletzungen an Bandern und Kapsel beleuchtet. Neben der grossen medialen Valgusinstabilitat werden die verschiedenen Schweregrade der Bandverletzungen und die Lokalosation der Risse ebenso behandelt wie die therapeutischen Moglichkeiten. Hier stehen vor allem das operative Verfahren und die unterschieldichen Zugangs- und Rekonstruktionsmoglichkeiten im Vordergrund. more...

Context Patellar dislocation usually occurs to the lateral side, leading to ruptures of the Medial Patellofemoral Ligament (MPFL) in about 90% of the cases. Even though several prognostic factors are identified for patellofemoral instability after patellar dislocation so far, the appropriate therapy remains a controversial issue. Evidence Acquisition Authors searched the Medline library for studies on both surgical and conservative treatment for patellar dislocation and patellofemoral instability. Additionally, the reference list of each article was searched for additional studies. Results A thorough analysis of the anatomical risk factors with a particular focus on patella alta, increased Tibial Tuberosity-Trochlear Groove (TT-TG) distance, trochlear dysplasia as well as torsional abnormalities should be performed early after the first dislocation to allow adequate patient counseling. Summarizing the results of all published randomized clinical trials and comparing surgical and conservative treatment after the first-time patellar dislocation until today indicated no significant evident difference for children, adolescents, and adults. Therefore, nonoperative treatment was indicated after a first-time patellar dislocation in the vast majority of patients. Conclusions Surgical treatment for patellar dislocation is indicated primarily in case of relevant concomitant injuries such as osteochondral fractures, and secondarily for recurrent dislocations. more...

INTRODUCTION: Gymnastic school sport injuries account for a significant morbidity and mortality among children and adolescents. Preventive issues may be derived from a thorough in-depth analysis of the pattern and circumstances of gymnastic injuries. METHODS: During a school year among 3993 schools in 43 889 classes with 993 056 pupils 2234 school sport injuries have been reported to the Gemeinde Unfall Versicherung (GUV) Niedersachsen, Germany. RESULTS: Gymnastic sport injuries account for 18 % (403 accidents), which is second after ball sports injuries. Regarding the distribution of the gymnastic disciplines, vault was the major discipline with 34 %, followed by floor exercise (21.3 %), mini- and competition trampoline (16.8 %), and parallel bars (8.2 %). The analysis of the type of injury during vault accidents revealed contusion (31 %) as the predominant injury, followed by sprains (15.4 %), and fractures (15.4 %). Floor exercise injuries distributed among distorsions (26.7 %), contusions (18.6 %), muscle tears (14 %). Back injuries especially of the cervical and thoracic spine, accounted for 40 % of all their injuries. Minor head injuries account for 4.7 % of all floor exercise injuries. Mini-trampoline injuries distribute among contusions (30 %), fractures (22.5 %), distorsions (7.5 %). 21.8 % collisions were noted against a box in comparison to 6.8 % in case of the horse. CONCLUSION: Gymnast injuries account for a significant number of all school sport related injuries. Vault and floor exercise account for the vast majority of all injuries, with alarming high numbers of spine injuries during floor exercise and mini-trampoline. A preservation of a high level of attention during a sport lesson, safety measures including appropriate mats and landing zones are mandatory to reduce injuries. Muscle injuries and ankle sprains can be prevented by a prospective proprioceptive training intervention to be implemented in school sports. Language: de more...

PURPOSE: Does a prospective proprioceptive-coordinative additional training intervention in elite female soccer changes frequency and pattern of injuries? MATERIALS AND METHODS: 24 female soccer players of the German first division team of FC Bayern Manchen were thoroughly supervised during the season 2003/04 regarding injuries resulting in an absence from at least one scheduled training session or game. During the winter break an additional proprioceptive-coordinative training program was initiated, which was performed on a regular basis during the second half of the season. Furthermore, we evaluated jump and reach, throwing power, coordinative skills, and flexibility. RESULTS: All evaluated fitness results increased significantly during the season after the training intervention, such as jump and reach 44 +/- 4 cm vs. 38 +/- 10 cm (p < 0.05), coordinative power left and right leg, respectively (71 +/- 44 s vs. 45 +/- 37 s, 80 +/- 41 s vs. 50 +/- 32 s, both p < 0.05), flexibility left and right hip (89 +/- 8 degrees vs. 78 +/- 13 degrees and 88 +/- 9 degrees vs. 79 +/- 10 degrees , p < 0.05). Comparing the 1 (st) to the 2 (nd) half of the season, 25 vs. 26 injuries after foulplay and 69 vs. 52 without contact occur (p < 0.05). Muscle injuries resulting in game or training absence were significantly reduced by 400 % (12 vs. 3, p < 0.05). In the 1 (st) half of the season, 2 anterior cruciate ruptures (ACL) occur vs. none in the 2 (nd) half after the training intervention. CONCLUSION: An additional proprioceptive-coordinative training intervention increases coordinative abilities, jump power, throwing power, and flexibility during a half season. After initiation of the proprioceptive-coordinative training the incidence of muscle injuries resulting in an absence of at least one game or practice session was reduced significantly by 400 %. Regarding the reduced incidence of ACL injuries after proprioceptive-coordinative training in female elite soccer players, further studies have to be perfomed to elucidate the value of this training intervention. more...

Purpose: Ball sport school injuries account for a significant morbidity among children and adolescents. Materials and Methods: During a school year 2234 school sport injuries have been reported to the Gemeinde Unfall Versicherung (GUV) Niedersachsen, Germany. Results: Regarding the non-gender-specific distribution of the ball sport disciplines, basketball leads with 32 % (n = 431), followed by soccer (24 %, n = 316), volleyball (17 %, n = 232), handball (8.3 %, n = 110) and hockey (4.9 %, n = 65). Sprains (27 %) dominate in basketball, followed by ligament distorsions and ruptures (23 %) and fractures (21 %), with frequent finger injuries (61 %) without contact of an opponent, and injuries of the lower extremity (28 %). Soccer leads to contusions (29 %), in 52 % of the lower extremity frequently after collision with an opponent (22 %) or the ball (20 %). In volleyball upper extremity injuries (71 %) dominate with 53 % finger sprains in individual volleyball play. Conclusion: Ball school sport injuries account for a significant morbidity with frequent finger injuries. Proprioceptive deficits may play a role in those finger injuries in basketball, volleyball and handball. During hockey, severe dental and facial injuries were apparent. A prospective proprioceptive trainings program aiming on fingers and the ankle region may therefore be a preventive measure such as helmets with facial protection in hockey school sport. Originalarbeit more...

PURPOSE The purpose of this study was to investigate press fit femoral fixation of hamstring tendons and to compare the mechanical properties with press fit patellar tendon bone (PTB) fixation. METHODS The PTB and hamstring tendons of 30 human cadavers (age: 55.8+/-18.0 years) were used as grafts. An outside-in press fit fixation with a knot in the semitendinosus and gracilis graft (SG-K) and an inside-out (SG-BI) and an outside-in fixation (SG-BO) with the tendons looped over a bone block were compared with a bone-patellar tendon (PT) press fit fixation in 30 bovine femora. The angle between the direction of force and bone tunnel was 60 degrees. The constructs underwent 20 cycles of loading between 60 and 260 N. Constructs were loaded until failure at a speed of 1 mm/sec. Graft fixation was analyzed in terms of maximum load to failure, stiffness and elongation during cyclic stretching. A video analysis of length changes was investigated. RESULTS There was a significant difference in the maximum load to failure. The SG-BI fixation was inferior to the other three techniques (Mann-WhitneyU-test, P more...

Fragestellung: Ziel der experimentellen Studie war die quantitative Evaluierung der Meniskusbewegung und -verformung in vivo unter Gewichtsbelastung. Methode: Sagittale T1-gewichtete MRT-Bilder von 15 gesunden Kniegelenken wurden ausgewertet. In einem offenen MR wurden die Probanden so platziert, dass eine Messung unter Belastung und in verschiedenen Beugegraden moglich war. Es wurden Bilderserien vom Innen- und Ausenmeniskus ohne Belastung, mit halbem und vollem Korpergewicht angefertigt. Alle Aufnahmen erfolgten in voller Streckung und in 30°-Beugung. Zwei Untersucher masen je zweimal die Hohe des Hinterhorns und den inneren und auseren Abstand zwischen Vorder- und Hinterhorn der Menisken. Ergebnisse: Die Hohe des Innen- und Ausenmeniskushinterhorns nahm unter zunehmender Gewichtsbelastung ab. Innen- und Ausenabstand nahmen unter Gewichtsbelastung zu. Hierbei nahm der Innenabstand starker zu als der Ausenabstand, was eine Kompression der Peripherie bedeutet. Zunehmende Flexion von 0 auf 30° hatte nur auf den Ausenabstand signifikanten Einfluss. Schlussfolgerungen: Die Methode kann in Zukunft zur funktionellen, postoperativen Nachkontrolle bei verschiedenen meniskuserhaltenden oder -ersetzenden Therapieverfahren eingesetzt werden. Die nachgewiesene Kompression der Meniskusperipherie von innen nach ausen bei Belastung in voller Extension erlaubt die fruhe postoperative Mobilisation nach Meniskusnaht. Aim: The aim of this experimental study was a quantitative evaluation of meniscal movement and deformation in vivo under load bearing conditions. Methods: Sagittal T1-weighted MRI pictures of 15 healty knees were evaluated. The subjects were placed in an open MRI, that enabled measurements under load bearing and in different flexion grades. Series of pictures of the medial and lateral meniscus without load, with half and full body weight load and in full extension and 30° flexion were taken. Two examiners measured twice the height of the posterior horn, and the inner and outer distance between the anterior and posterior horns of the menisci. Results: The height of the posterior horns of the medial and lateral menisci decreased with increasing load. The inner and outer distance increased with load, the inner distance more than the outer, resulting in a compression of the periphery. Increase of flexion from 0° to 30° significantly influenced only the outer distance of both menisci. Conclusion: This method can be used in future to functionally evaluate the postoperative result after meniscus saving or replacing therapies. The compression of meniscal periphery from the inside to the outside under load in full extension allows early postoperative mobilisation after meniscal sutures. more...

Prefabrication of bone transplants is a promising option for large defects of the long bones, especially if there is compromised vascularization of the defect. This is especially true for postinfection bone defects and other types of atrophic nonunion. The generation of a foreign body membrane (Masquelet's technique) has been investigated in order to ameliorate the response of the host tissue surrounding the defect. In an experimental animal study, a blood vessel within a bone construct could be used to generate customized, vascularized osteogenic constructs that can be used to treat large bone defects in the future. more...

In the context of acute knee dislocations, suture repair of ruptured cruciate ligaments leads to good clinical results in 80% of cases. Disadvantages are low primary stability and subsequently secondary elongation of the sutured ligaments. In the present study, we compared primary stability of suture repair, reinforced by different suture augments, to cruciate ligament reconstruction.The concept of ligament bracing with transosseous suture repair of the cruciate ligaments and additional suture augmentation is biomechanically superior to cruciate ligament reconstruction.A total of 42 porcine knee joints divided into seven groups were examined. The stability of four different suture/augmentation combinations were compared to cruciate ligament reconstruction with human hamstring tendons. The investigational setup consisted of testing 1000 cycles with 20 N to 154 N load in a.-p. translation and 60° flexion. Elongation and load to failure were measured.Neither reconstruction (3.13 ± 1.65 mm; 362 ± 51 N) nor augmented suture repair (1.89-2.5 mm; 464-624 N) achieved the primary stability of the intact cruciate ligament (0.63 ± 0.34 mm, 1012 ± 91 N). In comparison to ligament reconstruction, all four augmented suture repairs showed minor elongation in the cyclic test and a higher load to failure. The isolated suture repair showed poor results (6.79 ± 4.86 mm, 177 ± 73 N).Augmented suture repair provides significantly higher stability compared with isolated suture repair and reconstruction with hamstring tendons. The concept of ligament bracing could be a promising future treatment option in acute knee dislocations. Clinical results remain to be seen. more...

The purpose of this study was to analyze the accuracy of commonly used techniques for the measurement of knee extension and to compare them with a new measurement device. The bars of an external fixator were used to determine reference knee extension angles of 15 human cadavers. These angles were compared with measurements of knee extension on radiographs limited to the knee joint. Extension was determined in various knee positions using a generic goniometer and a novel long arm goniometer. In a clinical study, two independent examiners categorized knee extension performance according to the IKDC. Sixteen knees with deficits in the range of motion were rated using a generic goniometer, a long arm goniometer and the novel extension measurement device. The radiological measurement of knee extension angles that were restricted to the shaft of femur and tibia had a systematic error of -5.2 +/- 1.9 degrees compared with the lines created by the centers of rotation. In the experimental setup, the mean absolute deviations were 3.92 +/- 1.41 degrees with a generic goniometer and 1.22 +/- 0.20 degrees with the extension measurement device. The variance of the measurements was significantly lower (2.64 +/- 0.28) than with the generic goniometer (23.72 +/- 4.39; P0.05). Correspondence in the IKDC rating was 63% using a standard goniometer, 50% with the long arm goniometer, and 96% using the novel device. Radiological measurements of knee extension limited to the area of the knee joint deviates systematically from measurements of the total axis of the bones. A precision goniometer that utilizes bony landmarks of the tibia and femur is superior in accuracy compared with standard and long arm goniometer techniques. more...

Ruptures of the patellar tendon are less often observed compared to those of the Achilles or quadriceps tendon. A bilateral rupture is a rarity. Steroid medications or a variety of systemic diseases are associated with spontaneous tendon ruptures. Less often traumatic rupture is the result of severe overloading of the extensor mechanism of the knee. We report on a 60-year-old female without an obvious trauma, systemic disease or medication who suffered a spontaneous bilateral patellar tendon rupture. more...

(1997). Cooperative Web Weaving: The Team Approach to Web Site Development at Illinois State University. Journal of Interlibrary Loan, Document Delivery & Information Supply: Vol. 8, No. 2, pp. 1-20. more...

Intracondylar deformities after tibial plateau fractures are intra-articular deformities which present within the medial and/or lateral knee compartments. They exist either isolated or in combination with other extra-articular deformities and/or ligament problems. These deformities are complex problems and difficult to treat. While many treatment concepts exist for extra-articular deformities there is limited information available for intra-articular or even intracondylar deformities. Selecting the appropriate procedure for the approach, osteotomy, management of bone defects and cartilage damage is crucial. The authors describe the analysis, planning, treatment and clinical outcome for these rare but difficult problems and present step by step details of the surgical technique. more...

Complex ligament injuries can compromise a knee joint and residual conditions comprise stiffness (arthrofibrosis), instability, cartilage damage leading to osteoarthritis and bone deformity. Accurate diagnosis must address the direction and extent of the instability, the severity of any cartilage lesion and an analysis of the axis and bone deformity as well as important cofactors. Therapeutic options are adhesiolysis, ligament reconstruction, cartilage regeneration and axis correction. As a consequence patients mostly profit from the procedure but there is never a return to the functional level that existed before injury. more...

Double-bundle ACL reconstruction has been demonstrated to be at least as effective as single-bundle reconstruction in terms of restoring knee rotational and translational stability. Until now, the influence on knees with hyperextension has not been evaluated. It was the purpose of this study to evaluate whether double-bundle ACL reconstruction restricts extension in hyperextendable knees. Hamstring tendon reconstructions of 10 human cadaveric knees with the ability of hyperextension (age: 48 ± 14 years) were performed as single bundle (SB) on one side and double bundle (DB) on the other side. A surgical navigation system (BrainLab, Germany) was used to assess the kinematics of each knee at the intact and reconstructed state. A difference with regard to the anterior-to-posterior translation (AP) and rotational stability at 30° of knee flexion, 90° of flexion and the hyperextension capability of each specimen was analysed. The difference in AP translation before and after the reconstruction was not significantly different in 30° and 90° of flexion (n.s). Both single- and double-bundle reconstructions restored the preoperative kinematics at 30° and 90° of knee flexion (n.s). The knee extension was 4° ± 1.8° with the intact ACL and 4° ± 1.7° after reconstruction in the SB group (n.s). The knee extension was 5° of hyperextension ± 1.1° with the intact ACL and 0° ± 0.4° after reconstruction in the DB group; the limitation of the extension was significantly larger in this group (p = 0.013). Both single- and double-bundle ACL reconstruction techniques are capable of restoring knee anteroposterior and rotational stability. Double-bundle reconstructions significantly reduce knee extension in knees with hyperextension capability. Care must be taken when using double-bundle techniques in patients with knee hyperextension as this procedure may limit the knee extension after double-bundle ACL reconstruction. more...

Der Gebrauch von Saugdrainagen in der Unfallchirurgie ist heute bei der Mehrzahl von unfallchirurgischen Eingriffen an Knochen und Gelenken ublich.Wahrend bis in die 80er-Jahre empirische Empfehlungen zur Verwendung von Redon-Drainagen bestanden, sind in den letzten 20 Jahren zahlreiche randomisierte, kontrollierte Untersuchungen durchgefuhrt worden.In diesem Ubersichtsartikel werden Studien fur die in der Unfallchirurgie relevanten Gebiete diskutiert. Randomisierte, kontrollierte Studien zeigen keinen positiven Einfluss von Saugdrainagen auf das Operationsergebnis in Hinblick auf Revisionsraten oder Langzeitergebnis.Dies gilt auch fur die Endoprothetik und komplikationstrachtige Eingriffe wie Beckenkammspanentnahme. Daruber hinaus zeigen einige Studien die erhohte Rate an septischen Komplikationen. Eine evidencebasierte Chirurgie sollte die Verwendung von Saugdrainagen auserst kritisch bewerten, die Akzeptanz dieser Erkenntnisse ist allerdings bisher gering. more...

A secure tibial press fit technique in posterior cruciate ligament reconstructions may be a relevant alternative to common techniques because no hardware is necessary. Up to the present point in time no biomechanical data exist for a tibial press fit posterior cruciate ligament (PCL) reconstruction. This study compares the biomechanical properties of hamstring and quadriceps tendon grafts using a press fit technique with those of an interference screw fixation.Quadriceps and hamstring tendons of 20 human cadavers (age 49.2±18.5 years) were used. A press fit fixation with a knot in the semitendinosus tendon (K) and a quadriceps tendon bone block graft (Q) were compared to an interference screw fixation (I) in 27 porcine tibiae. In each group, nine constructs were cyclically stretched and then loaded until failure. Maximum load to failure, stiffness and elongation during failure testing and cyclical loading were investigated.The maximum load to failure was 518±157 N (387-650 N) for the K group, 558±119 N (466-650 N) for the I group and 620±102 N (541-699 N) for the Q group. The stiffness was 55±27 N/mm (18-89 N/mm) for the K group, 117±62 N/mm (69-165 N/mm) for the I group and 65±21 N/mm (49-82 N/mm) for the Q group. The stiffness of the I group was significantly larger (ANOVA on ranks, P=0.01). The elongation during cyclical loading was significantly larger for all groups from the 1st to the 5th cycle compared to the elongation in between the 5th and the 20th cycle (P0.03).All techniques exhibited larger elongation during initial loading. Load to failure and stiffness were significantly different between the fixations. The Q fixation showed equal biomechanical properties compared to a pure tendon fixation (I) with an interference screw. The results of group K were inferior. All three investigated fixation techniques exhibit comparable biomechanical properties. Preconditioning of the constructs is critical. Future randomized, clinical trials have to investigate the biological effectiveness of these fixation techniques. more...

Patellar dislocation is a common knee injury with mainly lateral dislocations, leading to ruptures of the medial patellofemoral ligament in most of the cases. Reliable data and prognostic factors for stability of the patellofemoral joint and satisfaction of the patient after either conservative or operative treatment have not been established yet. Until now, there are no randomized controlled trials for recurrent patellar dislocation at all. As a synopsis of the randomized controlled trials about first-time patellar dislocation, no significant difference between operative and conservative management is evident. This applies to both children and adolescents as well as to adults. There is a clear tendency towards first-line conservative therapy after traumatic patellar dislocation. Operative treatment is only required in case of accompanying injuries like osteochondral fractures or in case of recurrent dislocations. Further prospective randomized controlled trials with standardized operative and conservative treatment and patient cohorts of sufficient size are necessary in the future. more...

We present a literature review about implant removal after operative extremity and spine fracture treatment. The indication for implant removal procedures has become less frequent in recent years, but is still more common in Europe than for example in North America. The time required to perform a implant removal can easily exceed the planned amount. Implant removal can result in significant complications like soft tissue damage, fractures, infections, and other problems. Not only because of these problems, the decision on whether or not to remove the implant should be made with great care. Therefore good communication with the patient and thorough information about risks and benefits are essential. more...