Lakemeier, Stefan

[["dc.bibliographiccitation.firstpage","473"],["dc.bibliographiccitation.issue","6"],["dc.bibliographiccitation.journal","Biomedical Engineering / Biomedizinische Technik"],["dc.bibliographiccitation.lastpage","480"],["dc.bibliographiccitation.volume","57"],["dc.contributor.author","Foelsch, Christian"],["dc.contributor.author","Goost, Hans"],["dc.contributor.author","Figiel, Jens"],["dc.contributor.author","Paletta, Juergen R. J."],["dc.contributor.author","Schultz, Wolfgang"],["dc.contributor.author","Lakemeier, Stefan"],["dc.date.accessioned","2018-11-07T09:02:38Z"],["dc.date.available","2018-11-07T09:02:38Z"],["dc.date.issued","2012"],["dc.description.abstract","Background: Cement augmentation of pedicle screws increases fixation strength in an osteoporotic spine. This study was designed to determine the cement distribution and the correlation between the pull-out strength of the augmented screw and the cement volume within polyurethane (PU) foam. Methods: Twenty-eight cannulated pedicle screws (6 x 45 mm) (Peter Brehm, Erlangen, Germany) with four holes at the distal end of the screw were augmented with the acrylic Stabilit ER Bone Cement Vertebral Augmentation System (DFine Inc., San Jose, CA, USA) and implanted into open-cell rigid PU foam (Pacific Research Laboratories, Vashon Island, WA, USA) with a density of 0.12 g/cm(3), resembling severe osteoporosis. Volumetric measurement of the cement with consideration of the distribution around the screws was done with multislice computed tomography scan (Somatom Definition, Siemens, Erlangen, Germany). Pull-out strength was tested with a servohydraulic system (MTS System Corporation, Eden Prairie, MN, USA), and nonaugmented screws served as control. Pearson ' s correlation coefficient with significance level a = 0.05 and one-way analysis of variance test were used. Results: We found a high (r = 0.88) and significant (p < 0.01) correlation between the cement volume and the pull-out strength, which increased by more than 5-fold with a volume of 3 ml. The correlation appeared linear at least up to 4 ml cement volume and failure always occurred at the cement-bone interface. The cement distribution was symmetric and circular around the most proximal hole, with a distance of 14 mm from the tip, and nearly 90% of the cement was found 6 mm distal and cranial to it. The 95% confidence interval for the relative amount of cement was 37% -41% within 2 mm of the most proximal hole. Conclusion: Compared with the control, a cement volume between 2.0 and 3.0 ml increased the pull-out strength significantly and is relevant for clinical purposes, whereas a volume of 0.5 ml did not. A cement volume beyond 3.0 ml should further increase the pull-out strength because the correlation was linear at least up to 4.0 ml, but the possibility of in vivo cement leakage with increasing volume has to be considered. Pressure-controlled cement application might be a tool to avoid this complication. The cement almost completely penetrated the most proximal perforation."],["dc.identifier.doi","10.1515/bmt-2012-0012"],["dc.identifier.isi","000312707900007"],["dc.identifier.pmid","23152399"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/10598"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/24730"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Walter De Gruyter & Co"],["dc.relation.issn","0013-5585"],["dc.rights","Goescholar"],["dc.rights.uri","https://goescholar.uni-goettingen.de/licenses"],["dc.title","Correlation of pull-out strength of cement-augmented pedicle screws with CT-volumetric measurement of cement"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","359"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","Acta Neurochirurgica"],["dc.bibliographiccitation.lastpage","365"],["dc.bibliographiccitation.volume","154"],["dc.contributor.author","Lakemeier, Stefan"],["dc.contributor.author","Schmid, Raphael"],["dc.contributor.author","Foltz, Lisa"],["dc.contributor.author","Rohlfs, Jochen"],["dc.contributor.author","Fuchs-Winkelmann, Susanne"],["dc.contributor.author","Efe, Turgay"],["dc.contributor.author","Foelsch, Christian"],["dc.contributor.author","Paletta, Jürgen R. J."],["dc.date.accessioned","2019-07-09T11:54:37Z"],["dc.date.available","2019-07-09T11:54:37Z"],["dc.date.issued","2011"],["dc.description.abstract","Background The most common spinal disorder in the elderly is lumbar spinal stenosis (LSS), which results in part from ligamentum flavum (LF) hypertrophy. Although prior histologic and immunochemical studies have been performed in this area, the pathophysiology of loss of elasticity and hypertrophy is not completely understood. The purpose of this immunohistological study is to elucidate the role of CD44 and its splice variants CD44v5 and CD44v6 in the hypertrophied LF obtained from patients with lumbar spinal stenosis (LSS). Materials and methods LF samples of 38 patients with LSS were harvested during spinal decompression. Twelve LF samples obtained from patients with disc herniation and no visible degeneration on preoperative MRI were obtained as controls. Samples were dehydrated and embedded in paraffin. For immunohistochemical determination, slices were stained with antibodies against CD44, Cd44v4, and CD44v6 stained with DAB. LF hypertrophy and cross-sectional area (CSA) were measured with T1-weighted MRI. Results CD44 and CD44v5 expression were significantly increased in the hypertrophy group (p<0.05). CD44v6 expression was not significantly increased. The number of elastic fibers was significantly higher in the hypertrophy group. In the hypertrophy group, LF thickness was significantly increased while CSA was significantly decreased. There was a statistical correlation between LF thickness, CSA, CD44, and CD44v5 expression in the hypertrophy group (p<0.05). Conclusions LF hypertrophy is accompanied by increased CD44 and CD44v5 expression. CD44v6 expression is not enhanced in LF hypertrophy."],["dc.format.extent","7"],["dc.identifier.doi","10.1007/s00701-011-1206-z"],["dc.identifier.fs","593532"],["dc.identifier.pmid","22052472"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/9467"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/60696"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.relation.issn","0942-0940"],["dc.rights","Goescholar"],["dc.rights.uri","https://goescholar.uni-goettingen.de/licenses"],["dc.title","Increased expression of CD44 in hypertrophied ligamentum flavum and relevance of splice variants CD44v5 and CD44v6"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","335"],["dc.bibliographiccitation.issue","5"],["dc.bibliographiccitation.journal","PM&R"],["dc.bibliographiccitation.lastpage","341"],["dc.bibliographiccitation.volume","4"],["dc.contributor.author","Foelsch, Christian"],["dc.contributor.author","Schloegel, Stefanie"],["dc.contributor.author","Lakemeier, Stefan"],["dc.contributor.author","Wolf, Udo"],["dc.contributor.author","Timmesfeld, Nina"],["dc.contributor.author","Skwara, Adrian"],["dc.date.accessioned","2018-11-07T09:10:33Z"],["dc.date.available","2018-11-07T09:10:33Z"],["dc.date.issued","2012"],["dc.description.abstract","Objective: To explore the reliability of the Zebris CMS 20 ultrasound analysis system with pointer application for measuring end-range flexion, end-range extension, and neutral kyphosis angle of the thoracic spine. Setting: The study was performed within the School of Physiotherapy in cooperation with the Orthopedic Department at a University Hospital. Participants: The thoracic spines of 28 healthy subjects were measured. Methods: Measurements for neutral kyphosis angle, end-range flexion, and end-range extension were taken once at each time point. The bone landmarks were palpated by one examiner and marked with a pointer containing 2 transmitters using a frequency of 40 kHz. A third transmitter was fixed to the pelvis, and 3 microphones were used as receiver. The real angle was calculated by the software. Bland-Altman plots with 95% limits of agreement, intraclass correlations (ICC), standard deviations of mean measurements, and standard error of measurements were used for statistical analyses. The test-retest reliability in this study was measured within a 24-hour interval. Main Outcome Measurements: Statistical parameters were used to judge reliability. Results: The mean kyphosis angle was 44.8 degrees with a standard deviation of 17.3 degrees at the first measurement and a mean of 45.8 degrees with a standard deviation of 16.2 degrees the following day. The ICC was high at 0.95 for the neutral kyphosis angle, and the Bland-Altman 95% limits of agreement were within clinical acceptable margins. The ICC was 0.71 for end-range flexion and 0.34 for end-range extension, whereas the Bland-Altman 95% limits of agreement were wider than with the static measurement of kyphosis. Compared with static measurements, the analysis of motion with 3-dimensional ultrasound showed an increased standard deviation for test-retest measurements. Conclusions: The test-retest reliability of ultrasound measuring of the neutral kyphosis angle of the thoracic spine was demonstrated within 24 hours. Bland-Altman 95% limits of agreement and the standard deviation of differences did not appear to be clinically acceptable for measuring flexion and extension. PM R 2012;4:335-341"],["dc.identifier.doi","10.1016/j.pmrj.2012.01.009"],["dc.identifier.isi","000305872800003"],["dc.identifier.pmid","22464951"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/26518"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Inc"],["dc.relation.issn","1934-1482"],["dc.title","Test-Retest Reliability of 3D Ultrasound Measurements of the Thoracic Spine"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","585"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","Archives of Orthopaedic and Trauma Surgery"],["dc.bibliographiccitation.lastpage","592"],["dc.bibliographiccitation.volume","136"],["dc.contributor.author","Foelsch, Christian"],["dc.contributor.author","Federmann, Maike"],["dc.contributor.author","Lakemeier, Stefan"],["dc.contributor.author","Kuehn, Klaus D."],["dc.contributor.author","Kittinger, Clemens"],["dc.contributor.author","Kerwat, Martina"],["dc.contributor.author","Fuchs-Winkelmann, Susanne"],["dc.contributor.author","Paletta, Juergen R. J."],["dc.contributor.author","Roessler, Philip P."],["dc.date.accessioned","2018-11-07T10:16:24Z"],["dc.date.available","2018-11-07T10:16:24Z"],["dc.date.issued","2016"],["dc.description.abstract","Treatment of implant-associated osteomyelitis regularly involves the use of systemic antibiotics in addition to surgical intervention. However, it remains unclear if perioperative systemic application of bactericide substances can improve overall outcome in models of severe intramedullary infection. The present study investigated the use of systemic gentamicin in addition to a controlled local release from a highly lipophilic gentamicinpalmitate compound while the previous study showed efficacy of sole antibiotic implant-coating. Forty male Sprague-Dawley rats were divided into two groups receiving an intramedullary femoral injection of 10(2) CFU of a common methicillin susceptible Staphylococcus aureus strain (MSSA Rosenbach). Group I received an uncoated implant whereas group II received a coated implant. All animals received a single shot intraperitoneal application of gentamicinsulfate directly after wound closure while the historical control group III (n = 20) had no antibiotic treatment at all. Animals were observed for 28 and 42 days. Serum haptoglobin and relative weight gain were assessed as well as roll over cultures of explanted femur nails and histological scores of periprosthetic infection in dissected femora. Systemic application of gentamicin combined with antibiotic-coated implant did not further reduce bacterial growth significantly compared with systemic or local antibiotic application alone. Combined local and systemic therapy reduced serum haptoglobin significantly after day 7, 28 and 42 whereas systemic application alone did not compare to controls. Systemic perioperative and implant-associated application of antibiotics were both comparably effective to treat implant-associated infections whereas the combined antibiotic therapy further reduced systemic signs of infection time dependent."],["dc.description.sponsorship","Synthes GmbH, Umkirch, Germany"],["dc.identifier.doi","10.1007/s00402-016-2419-7"],["dc.identifier.isi","000373179000020"],["dc.identifier.pmid","26873243"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/41032"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Springer"],["dc.relation.issn","1434-3916"],["dc.relation.issn","0936-8051"],["dc.title","Systemic antibiotic therapy does not significantly improve outcome in a rat model of implant-associated osteomyelitis induced by Methicillin susceptible Staphylococcus aureus"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","228"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Anesthesia & Analgesia"],["dc.bibliographiccitation.lastpage","235"],["dc.bibliographiccitation.volume","117"],["dc.contributor.author","Lakemeier, Stefan"],["dc.contributor.author","Lind, Marcel"],["dc.contributor.author","Schultz, Wolfgang"],["dc.contributor.author","Fuchs-Winkelmann, Susanne"],["dc.contributor.author","Timmesfeld, Nina"],["dc.contributor.author","Foelsch, Christian"],["dc.contributor.author","Peterlein, Christian D."],["dc.date.accessioned","2018-11-07T09:22:37Z"],["dc.date.available","2018-11-07T09:22:37Z"],["dc.date.issued","2013"],["dc.description.abstract","BACKGROUND: Lumbar facet joint degeneration is a source of chronic low back pain, with an incidence of 15% to 45% among patients with low back pain. Various therapeutic techniques in the treatment of facet-related pain have been described in the literature, including intraarticular lumbar facet joint steroid injections and radiofrequency denervation. In this study, we compared the effectiveness of intraarticular facet joint steroid injections and radiofrequency denervation. METHODS: Our randomized, double-blind, controlled study included patients who received intraarticular steroid infiltrations in the lumbar facet joints (L3/L4-L5/S1) and patients who underwent radiofrequency denervation of L3/L4-L5/S1 segments. The inclusion criteria were based first on magnetic resonance imaging findings showing hypertrophy of the facet joints L3/L4-L5/S1 and a positive response to an intraarticular test infiltration of the facet joints L3/L4-L5/S1 with local anesthetics. The primary end point was the Roland-Morris Questionnaire. Secondary end points were the visual analog scale and the Oswestry Disability Index. All outcome assessments were performed at baseline and at 6 months. RESULTS: Fifty-six patients were randomized; 24 of 29 patients in the steroid injection group and 26 of 27 patients in the denervation group completed the 6-month follow-up. Pain relief and functional improvement were observed in both groups. There were no significant differences between the 2 groups for the primary end point (95% confidence interval [CI], -3 to 4) and for both secondary end points (95% CI for visual analog scale, -2 to 1; 95% CI for Oswestry Disability Index, -18 to 0). CONCLUSIONS: Intraarticular steroid infiltration or radiofrequency denervation appear to be a managing option for chronic function-limiting low back pain of facet origin with favorable short- and midterm results in terms of pain relief and function improvement, but improvements were similar in both groups."],["dc.identifier.doi","10.1213/ANE.0b013e3182910c4d"],["dc.identifier.isi","000326512300034"],["dc.identifier.pmid","23632051"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/29390"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Lippincott Williams & Wilkins"],["dc.relation.issn","1526-7598"],["dc.relation.issn","0003-2999"],["dc.title","A Comparison of Intraarticular Lumbar Facet Joint Steroid Injections and Lumbar Facet Joint Radiofrequency Denervation in the Treatment of Low Back Pain: A Randomized, Controlled, Double-Blind Trial"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","400"],["dc.bibliographiccitation.issue","7"],["dc.bibliographiccitation.journal","Journal of Spinal Disorders & Techniques"],["dc.bibliographiccitation.lastpage","406"],["dc.bibliographiccitation.volume","26"],["dc.contributor.author","Lakemeier, Stefan"],["dc.contributor.author","Schofer, Markus D."],["dc.contributor.author","Foltz, Lisa"],["dc.contributor.author","Schmid, Raphael"],["dc.contributor.author","Efe, Turgay"],["dc.contributor.author","Rohlfs, Jochen"],["dc.contributor.author","Fuchs-Winkelmann, Susanne"],["dc.contributor.author","El-Zayat, Bilal F."],["dc.contributor.author","Paletta, Juergen R. J."],["dc.contributor.author","Foelsch, Christian"],["dc.date.accessioned","2018-11-07T09:19:12Z"],["dc.date.available","2018-11-07T09:19:12Z"],["dc.date.issued","2013"],["dc.description.abstract","Study Design:Immunohistological study.Objective:To elucidate the role of matrix metalloproteinases (MMPs), hypoxia-inducible factor-1 (HIF), and vascular endothelial growth factor (VEGF) in the hypertrophied ligamentum flavum (LF) obtained from patients with lumbar spinal stenosis (LSS).Summary of Background Data:The most common spinal disorder in the elderly is LSS, which results in part from LF hypertrophy. Although prior histologic and immunochemical studies have been performed in this area, the pathophysiology of loss of elasticity and hypertrophy is not completely understood.Methods:LF samples of 38 patients with LSS were harvested during spinal decompression. Twelve LF samples obtained from patients with disk herniation and no visible degeneration on preoperative magnetic resonance imaging were obtained as controls. Samples were dehydrated and paraffin embedded. For immunohistochemical determination of VEGF, HIF, and MMPs 1, 3, and 9 expression, slices were stained with VEGF, HIF, and MMP antibody dilution. Neovessel density and number of elastic fibers were counted after Masson-Goldner staining. LF hypertrophy and cross-sectional area (CSA) were measured on T1-weighted magnetic resonance imaging.Results:MMPs 1, 3, 9 and VEGF expression were significantly increased in the hypertrophy group (P<0.05). HIF expression was negative in both groups. Vessel density was increased in the hypertrophy group, although this was not statistically significant. The number of elastic fibres was significantly higher in the control group. In the hypertrophy group, LF thickness was significantly increased, whereas CSA was significantly decreased. There was a statistical correlation between LF thickness, CSA, MMP, and VEGF expression in the hypertrophy group (P<0.05).Conclusions:LF hypertrophy is accompanied by increased MMPs 1, 3, 9 and VEGF expression. Neovessel density is increased in hypertrophied LF. HIF is not expressed in hypertrophied LF."],["dc.identifier.doi","10.1097/BSD.0b013e3182495b88"],["dc.identifier.isi","000326398500015"],["dc.identifier.pmid","22323068"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/28585"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Lippincott Williams & Wilkins"],["dc.relation.issn","1539-2465"],["dc.relation.issn","1536-0652"],["dc.title","Expression of Hypoxia-inducible Factor-1 alpha, Vascular Endothelial Growth Factor, and Matrix Metalloproteinases 1, 3, and 9 in Hypertrophied Ligamentum Flavum"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]