In vitro testing of a funnel-tip catheter with different clot types to decrease clot migration in mechanical thrombectomy

BACKGROUND

Mechanical thrombectomy is the standard treatment for acute ischemic stroke in patients with large vessel occlusion and can be performed up to 24h after symptom onset. Despite high recanalization rates, embolism in new territories has been reported in 8.6% of the cases. Causes for this could be clot abruption during stent retrieval into the smaller opening of a standard distal access catheter, and antegrade blood flow via collaterals despite proximal balloon protection. A funnel-shaped tip with a larger internal diameter was developed to increase the rate of first-pass recanalization and to improve the safety and efficacy of mechanical thrombectomy.

METHODS

This in vitro study compared the efficacy of a funnel-shaped tip with a standard tip in combination with different clot compositions. Mechanical thrombectomy was performed 80 times for each tip, using two stent retrievers (Trevo XP ProVue 3/20 mm, 4/20 mm) and four different clot types (hard vs. soft clots, 0-24h vs. 72h aged clots).

RESULTS

Significantly higher first-pass recanalization rates (mTICI 3) were observed for the funnel-shaped tip, 70.0% versus 30.0% for the standard tip (absolute difference, 32; relative difference 57.1%; P < .001), regardless of the clot type and stent retriever. Recanalization could be increased using harder Chandler loop clots versus softer statically generated clots, as well as 0-24h versus 72h aged clots, respectively.

CONCLUSION

The funnel-shaped tip achieved higher first-pass recanalization rates than the smaller standard tip and lower rates of clot abruption at the tip. Clot compositions and aging times impacted recanalization rates.

Influence of neurovascular anatomy on perforation site in different mouse strains using the filament perforation model for induction of subarachnoid hemorrhage

BACKGROUND

Filament perforation is a widely-used method to induce subarachnoid hemorrhage (SAH) in mice. Whereas the perforation site has been assumed to be in the branching of middle cerebral artery (MCA) and anterior cerebral artery (ACA), we recently observed more proximal perforations.

METHODS

Filament perforation was performed in CD1- (n = 10) and C57Bl/6N-mice (n = 9) ex vivo. The filament was left in place and the perforation site was microscopically assessed. Digital subtraction angiography (DSA) was performed in CD1- (n = 9) and C57Bl/6J-mice (n = 29) and anatomical differences of the internal carotid artery (ICA) were determined.

RESULTS

Whereas in C57Bl/6N-mice perforation occurred in the proximal intracranial ICA in 89% (n = 8), in CD1-mice the perforation site was in the proximal ICA in 50% (n = 5), in the branching between MCA and ACA in 40% (n = 4), and in the proximal ACA in 10% (n = 1). DSA revealed a stronger angulation (p<0.001) of the ICA in CD1-mice (163.5±2.81°) compared to C57Bl/6J-mice (124.5±5.49°). Body weight and ICA-angle showed no significant correlation in C57Bl/6J- (r = -0.06, pweight/angle = 0.757) and CD1-mice (r = -0.468, pweight/angle = 0.242).

CONCLUSION

Filament perforation in mice occurs not only at the hitherto presumed branching between MCA and ACA, but seems to depend on mouse strain and anatomy as the proximal intracranial ICA may also be perforated frequently.

Longitudinal imaging and evaluation of SAH-associated cerebral large artery vasospasm in mice using micro-CT and angiography

Longitudinal in vivo imaging studies characterizing subarachnoid hemorrhage (SAH)-induced large artery vasospasm (LAV) in mice are lacking. We developed a SAH-scoring system to assess SAH severity in mice using micro CT and longitudinally analysed LAV by intravenous digital subtraction angiography (i.v. DSA). Thirty female C57Bl/6J-mice (7 sham, 23 SAH) were implanted with central venous ports for repetitive contrast agent administration. SAH was induced by filament perforation. LAV was assessed up to 14 days after induction of SAH by i.v. DSA. SAH-score and neuroscore showed a highly significant positive correlation (rsp = 0.803, p < 0.001). SAH-score and survival showed a negative significant correlation (rsp = -0.71, p < 0.001). LAV peaked between days 3-5 and normalized on days 7-15. Most severe LAV was observed in the internal carotid (Δmax = 30.5%, p < 0.001), anterior cerebral (Δmax = 21.2%, p = 0.014), middle cerebral (Δmax = 28.16%, p < 0.001) and basilar artery (Δmax = 23.49%, p < 0.001). Cerebral perfusion on day 5 correlated negatively with survival time (rPe = -0.54, p = 0.04). Arterial diameter of the left MCA correlated negatively with cerebral perfusion on day 3 (rPe = -0.72, p = 0.005). In addition, pseudoaneurysms arising from the filament perforation site were visualized in three mice using i.v. DSA. Thus, micro-CT and DSA are valuable tools to assess SAH severity and to longitudinally monitor LAV in living mice.

The synthesis of brominated-boron-doped PAHs by alkyne 1,1-bromoboration: mechanistic and functionalisation studies

The synthesis of a range of brominated-B n -containing (n = 1, 2) polycyclic aromatic hydrocarbons (PAHs) is achieved simply by reacting BBr3 with appropriately substituted alkynes via a bromoboration/electrophilic C-H borylation sequence. The brominated-B n -PAHs were isolated as either the borinic acids or B-mesityl-protected derivatives, with the latter having extremely deep LUMOs for the B2-doped PAHs (with one example having a reduction potential of E 1/2 = -0.96 V versus Fc+/Fc, Fc = ferrocene). Mechanistic studies revealed the reaction sequence proceeds by initial alkyne 1,1-bromoboration. 1,1-Bromoboration also was applied to access a number of unprecedented 1-bromo-2,2-diaryl substituted vinylboronate esters directly from internal alkynes. Bromoboration/C-H borylation installs useful C-Br units onto the B n -PAHs, which were utilised in Negishi coupling reactions, including for the installation of two triarylamine donor (D) groups onto a B2-PAH. The resultant D-A-D molecule has a low optical gap with an absorption onset at 750 nm and emission centered at 810 nm in the solid state.

Radiation-induced malignancies after intensity-modulated versus conventional mediastinal radiotherapy in a small animal model

A long-standing hypothesis in radiotherapy is that intensity-modulated radiotherapy (IMRT) increases the risk of second cancer due to low-dose exposure of large volumes of normal tissue. Therefore, young patients are still treated with conventional techniques rather than with modern IMRT. We challenged this hypothesis in first-of-its-kind experiments using an animal model. Cancer-prone Tp53^+/C273X knockout rats received mediastinal irradiation with 3 × 5 or 3 × 8 Gy using volumetric-modulated arc therapy (VMAT, an advanced IMRT) or conventional anterior-posterior/posterior-anterior (AP/PA) beams using non-irradiated rats as controls (n = 15/group, n_total = 90). Tumors were assigned to volumes receiving 90–107%, 50–90%, 5–50%, and <5% of the target dose and characterized by histology and loss-of-heterozygosity (LOH). Irradiated rats predominantly developed lymphomas and sarcomas in areas receiving 50–107% (n = 26) rather than 5–50% (n = 7) of the target dose. Latency was significantly shortened only after 3 × 8 Gy vs. controls (p < 0.0001). The frequency (14/28 vs. 19/29; p = 0.29) and latency (218 vs. 189 days; p = 0.17) of radiation-associated tumors were similar after VMAT vs. AP/PA. LOH was strongly associated with sarcoma but not with treatment. The results do not support the hypothesis that IMRT increases the risk of second cancer. Thus the current practice of withholding dose-sparing IMRT from young patients may need to be re-evaluated.

A Volumetric Method for Quantification of Cerebral Vasospasm in a Murine Model of Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) is a subtype of hemorrhagic stroke. Cerebral vasospasm that occurs in the aftermath of the bleeding is an important factor determining patient outcome and is therefore frequently taken as a study endpoint. However, in small animal studies on SAH, quantification of cerebral vasospasm is a major challenge. Here, an ex vivo method is presented that allows quantification of volumes of entire vessel segments, which can be used as an objective measure to quantify cerebral vasospasm. In a first step, endovascular casting of the cerebral vasculature is performed using a radiopaque casting agent. Then, cross-sectional imaging data are acquired by micro computed tomography. The final step involves 3-dimensional reconstruction of the virtual vascular tree, followed by an algorithm to calculate center lines and volumes of the selected vessel segments. The method resulted in a highly accurate virtual reconstruction of the cerebrovascular tree shown by a diameter-based comparison of anatomical samples with their virtual reconstructions. Compared with vessel diameters alone, the vessel volumes highlight the differences between vasospastic and non-vasospastic vessels shown in a series of SAH and sham-operated mice.

Assessing abrasion of orthodontic surface sealants using a modified ophthalmic optical coherence tomography device

OBJECTIVE

Optical coherence tomography (OCT) is a clinical standard in ophthalmology. Currently, its application in dentistry is gaining increasing interest. In this study, we tested the possibility to use a modified commercially available spectral domain OCT (SD-OCT) to assess the layer thickness of orthodontic surface sealants.

MATERIALS AND METHODS

Reference samples of surface sealants for calibration and repeatability testing were measured using a micrometer screw. SD-OCT measurements were compared with micro-CT and light microscopic analyses. After validating the calibration of the SD-OCT, surface sealant layer thickness after aging (thermo cycling) and simulation of professional tooth cleaning (PTC) was assessed using the SD-OCT on 45 extracted teeth assigned to three test groups (n = 15 each): Light Bond™ Sealant, Pro Seal®, and Opal® Seal.

RESULTS

SD-OCT showed excellent repeatability and accuracy for measurements of surface sealant layer thickness. Compared with micro-CT, SD-OCT showed better accordance with the reference measurements. The analysis of surface sealants after thermo cycling and PTC revealed poor resistance of Light Bond after only aging and demonstrated substantial wear of all sealants after aging and PTC.

CONCLUSION

Imaging using commercially available ophthalmic SD-OCT might represent a suitable non-invasive methodology for longitudinal assessments of surface sealant layer thickness in vitro and in vivo.

CLINICAL RELEVANCE

SD-OCT might be a suitable non-invasive method for longitudinal assessments of surface sealant durability in clinical trials.

The HIV-derived protein Vpr52-96 has anti-glioma activity in vitro and in vivo

Patients with actively replicating human immunodeficiency virus (HIV) exhibit adverse reactions even to low irradiation doses. High levels of the virus-encoded viral protein R (Vpr) are believed to be one of the major underlying causes for increased radiosensitivity. As Vpr efficiently crosses the blood-brain barrier and accumulates in astrocytes, we examined its efficacy as a drug for treatment of glioblastoma multiforme (GBM).

In vitro, four glioblastoma-derived cell lines with and without methylguanine-DNA methyltransferase (MGMT) overexpression (U251, U87, U251-MGMT, U87-MGMT) were exposed to Vpr, temozolomide (TMZ), conventional photon irradiation (2 to 6 Gy) or to combinations thereof. Vpr showed high rates of acute toxicities with median effective doses of 4.0±1.1 μM and 15.7±7.5 μM for U251 and U87 cells, respectively. Caspase assays revealed Vpr-induced apoptosis in U251, but not in U87 cells. Vpr also efficiently inhibited clonogenic survival in both U251 and U87 cells and acted additively with irradiation. In contrast to TMZ, Vpr acted independently of MGMT expression.

Dose escalation in mice (n=12) was feasible and resulted in no evident renal or liver toxicity. Both, irradiation with 3×5 Gy (n=8) and treatment with Vpr (n=5) delayed intracerebral tumor growth and prolonged overall survival compared to untreated animals (n=5; p_{3×5 Gy}<0.001 and p_Vpr=0.04; log-rank test).

Our data show that the HIV-encoded peptide Vpr exhibits all properties of an effective chemotherapeutic drug and may be a useful agent in the treatment of GBM.

Low-energy extracorporeal shockwave therapy (ESWT) improves metaphyseal fracture healing in an osteoporotic rat model

Purpose

As result of the current demographic changes, osteoporosis and osteoporotic fractures are becoming an increasing social and economic burden. In this experimental study, extracorporeal shock wave therapy (ESWT), was evaluated as a treatment option for the improvement of osteoporotic fracture healing.

Methods

A well-established fracture model in the metaphyseal tibia in the osteoporotic rat was used. 132 animals were divided into 11 groups, with 12 animals each, consisting of one sham-operated group and 10 ovariectomized (osteoporotic) groups, of which 9 received ESWT treatment. Different energy flux intensities (0.15 mJ/mm², 0.35 mJ/mm², or 0.55 mJ/mm²) as well as different numbers of ESWT applications (once, three times, or five times throughout the 35-day healing period) were applied to the osteoporotic fractures. Fracture healing was investigated quantitatively and qualitatively using micro-CT imaging, quantitative real-time polymerase chain reaction (qRT-PCR) analysis, histomorphometric analysis and biomechanical analysis.

Results

The results of this study show a qualitative and quantitative improvement in the osteoporotic fracture healing under low-energy (energy flux intensity: 0,15 mJ/mm²) ESWT and with fewer treatment applications per healing period.

Conclusion

In conclusion, low-energy ESWT seems to exhibit a beneficial effect on the healing of osteoporotic fractures, leading to improved biomechanical properties, enhanced callus-quantity and -quality, and an increase in the expression of bone specific transcription factors. The results suggest that low-energy ESWT, as main treatment or as adjunctive treatment in addition to a surgical intervention, may prove to be an effective, simple to use, and cost-efficient option for the qualitative and quantitative improvement of osteoporotic fracture healing.

Vessel shape alterations of the vertebrobasilar arteries in Mucopolysaccharidosis type IVa (Morquio A) patients

PURPOSE

Main symptom of mucopolysaccharidosis type IVa (MPS IVa) is progressive systemic skeletal dysplasia. This is routinely monitored by cerebral and spinal MRI. The vascular system is generally not in the primary focus of interest. In our population of MPS IVa patients we observed vessel shape alterations of the vertebrobasilar arteries, which has not been described before.

MATERIAL AND METHODS

MRI-datasets of 26 patients with MPS IVa acquired between 2008 and 2015 were eligible for retrospective analysis of the vertebrobasilar arteries. The vessel length and angle of the basilar artery (BA) and both vertebral arteries (VA) were analyzed. A deflection angle between 90° and 130° in the vessel course was defined as tortuosity, less than 90° as kinking. The results were compared to a matched control group of 23 patients not suffering from MPS.

RESULTS

The deflection angle [°] of the VA and BA was significantly decreased in the majority (85%) of MPS IVa patients compared to the control group: BA 132±24 vs. 177±6, BA/VA transition 113±21 vs. 152±13, right VA 108±23 vs. 156±13, left VA 110± 22 vs. 157±14 (all p<0.005). Likewise, vessels of MPS IVa patients were significantly longer compared to the control group: BA 27±4 vs. 21±2, right VA 20±6 vs. 10±1, left VA 18±5 vs. 11±2 (all p<0.005).

CONCLUSION

MPS IVa is associated with significantly increased tortuosity of vertebrobasilar arteries. Therefore the vascular system of MPS IVa patients should be monitored on routinely basis, as vessel shape alterations had been associated with dissections, leading to a higher risk of cerebrovascular events.

A segmentation-based volumetric approach to localize and quantify cerebral vasospasm based on tomographic imaging data

Introduction

Quantification of cerebral vasospasm after subarachnoid hemorrhage (SAH) is crucial in animal studies as well as clinical routine. We have developed a method for computer-based volumetric assessment of intracranial blood vessels from cross-sectional imaging data. Here we demonstrate the quantification of vasospasm from micro computed tomography (micro-CT) data in a rodent SAH model and the transferability of the volumetric approach to clinical data.

Methods

We obtained rodent data by performing an ex vivo micro-CT of murine brains after sham surgery or SAH by endovascular filament perforation on day 3 post hemorrhage. Clinical CT angiography (CTA) was performed for diagnostic reasons unrelated to this study. We digitally reconstructed and segmented intracranial vascular trees, followed by calculating volumes of defined vessel segments by standardized protocols using Amira^® software.

Results

SAH animals demonstrated significantly smaller vessel diameters compared with sham (MCA: 134.4±26.9μm vs.165.0±18.7μm, p<0.05). We could highlight this difference by analyzing vessel volumes of a defined MCA-ICA segment (SAH: 0.044±0.017μl vs. sham: 0.07±0.006μl, p<0.001). Analysis of clinical CTA data allowed us to detect and volumetrically quantify vasospasm in a series of 5 SAH patients. Vessel diameters from digital reconstructions correlated well with those measured microscopically (rodent data, correlation coefficient 0.8, p<0.001), or angiographically (clinical data, 0.9, p<0.001).

Conclusions

Our methodological approach provides accurate anatomical reconstructions of intracranial vessels from cross-sectional imaging data. It allows volumetric assessment of entire vessel segments, hereby highlighting vasospasm-induced changes objectively in a murine SAH model. This method could also be a helpful tool for analysis of clinical CTA.

Imaging of Orthotopic Glioblastoma Xenografts in Mice Using a Clinical CT Scanner: Comparison with Micro-CT and Histology

Purpose

There is an increasing need for small animal in vivo imaging in murine orthotopic glioma models. Because dedicated small animal scanners are not available ubiquitously, the applicability of a clinical CT scanner for visualization and measurement of intracerebrally growing glioma xenografts in living mice was validated.

Materials and Methods

2.5x10⁶ U87MG cells were orthotopically implanted in NOD/SCID/ᵞc^-/- mice (n = 9). Mice underwent contrast-enhanced (300 μl Iomeprol i.v.) imaging using a micro-CT (80 kV, 75 μAs, 360° rotation, 1,000 projections, scan time 33 s, resolution 40 x 40 x 53 μm) and a clinical CT scanner (4-row multislice detector; 120 kV, 150 mAs, slice thickness 0.5 mm, feed rotation 0.5 mm, resolution 98 x 98 x 500 μm). Mice were sacrificed and the brain was worked up histologically. In all modalities tumor volume was measured by two independent readers. Contrast-to-noise ratio (CNR) and Signal-to-noise ratio (SNR) were measured from reconstructed CT-scans (0.5 mm slice thickness; n = 18).

Results

Tumor volumes (mean±SD mm³) were similar between both CT-modalities (micro-CT: 19.8±19.0, clinical CT: 19.8±18.8; Wilcoxon signed-rank test p = 0.813). Moreover, between reader analyses for each modality showed excellent agreement as demonstrated by correlation analysis (Spearman-Rho >0.9; p<0.01 for all correlations). Histologically measured tumor volumes (11.0±11.2) were significantly smaller due to shrinkage artifacts (p<0.05). CNR and SNR were 2.1±1.0 and 1.1±0.04 for micro-CT and 23.1±24.0 and 1.9±0.7 for the clinical CTscanner, respectively.

Conclusion

Clinical CT scanners may reliably be used for in vivo imaging and volumetric analysis of brain tumor growth in mice.

[Validity and Reliability of the German Version of the HSS Expectation Questionnaire on Hip Joint Replacement]

Background: Total hip arthroplasty is one of the most successful operations in medicine. The clinical result after surgery and compliance during rehabilitation are influenced by the patient's expectations. There is a lack of a validated German instrument to record these expectations in a standardised manner. Patients: 193 patients from the Dresden Hip Register with osteoarthritis of the hip were surveyed with respect to their expectations before the operation. The study sample consists of 108 women and 85 men. The average age of the patients was 59.7 years, with a standard deviation of 12.2 years. Methods: The Hospital for Special Patient Expectations Survey was translated into German and culturally adapted. In addition, the RKI demographic core data set, the HADS-D, LOT-R and the SCL-(K-)9 were collected to validate the instrument. In the statistical analysis, four main factors could be distinguished. These were "everyday activities", "pain relief and improvement in function", "medication and social participation" and "gait improvement". Results: Patients were predominantly married. 20 % of the women were widowed. 20 % had received higher education. Almost half of the patients were retired, 30 % were employed, 15.1 % self-employed and 7.3 % were unemployed. For most of the items, patients expected major improvements up to normalisation of their health. There were many different answers to several items, such as the question on occupation. For sporting and sexual activities no high expectations were given. The average expectation of the whole sample shows major differences to individual expectations. Men showed higher expectations for medication, social participation and gait improvement than did women. There were lower expectations for everyday activities, medication and social participation and gait improvement for older patients. Summary: The German version of the HSS patients expectation survey was validated. The instrument is useful in the preoperative setting to give the surgeon a first impression on the patient's expectations.

[Evidence-based trauma and orthopedic surgery : 20 years after Sackett]

The article "Evidence based medicine: what it is and what it isn't" published in the BMJ in 1996, is regarded as the foundation of the evidence-based medicine (EbM) movement. Approximately 5 years later David L. Sackett, one of the leaders of the movement, requested all experts to voluntarily abandon their position to make way for young researchers and fresh ideas. Since the term was first coined and the establishment of organizations and platforms fostering the idea, EbM has polarized clinicians and scientists around the world. Clinical and methodological developments during recent years have, however, overtaken the original principles of EbM. This review highlights the core concepts of EbM which have remained unchanged and valid for the current practice of trauma and orthopedic surgery and where revision is needed.

Testing clinical competencies in undergraduate nursing education using Objective Structured Clinical Examination (OSCE) – a literature review of international practice

Background: In response to demographic trends in Germany nursing competencies are currently reevaluated. Since these have to be taught and trained in nursing education programs, efficient verification of the success is necessary. OSCEs are internationally well-recognized as a comprehensive tool for that. Aim: In this analysis we identified competencies worldwide, which are tested by OSCEs in undergraduate nursing education programs. Method: An international literature research was conducted. The selection criterion for an article was the specification of at least one verifiable competency. Afterwards the competencies were categorized into knowledge, skills and attitudes according to the German “Fachqualifikationsrahmen Pflege für die hochschulische Bildung”. Results: A total of 36 publications fulfilled all inclusion criteria. Relevant studies were predominantly initiated in the UK, Canada and Australia. Within all categories a total of n = 166 different competencies are mentioned. OSCEs are developed and performed in a broad range of methods. Most frequently skills were verified. The most common topic was sure handling of medication. Other important themes were communicative competencies in relation to patients and the ability of self-evaluation. Discussion/Conclusions: A variation in examination methods is appropriate as different competencies are acquired in preparation of the test. Evaluation took place on an individual or institutional level. Further research is needed.

Feasibility, Safety, and Efficacy of Flow-Diverting Stent-Assisted Microsphere Embolization of Fusiform and Sidewall Aneurysms

BACKGROUND

Treatment of wide-necked internal carotid artery aneurysms is frequently associated with incomplete occlusion and high recurrence rates. Furthermore, platinum coils cause strong beam-hardening artifacts, hampering subsequent image analyses.

OBJECTIVE

To assess the feasibility, safety, and efficacy of flow-diverting, stent-assisted microsphere embolization of fusiform and sidewall aneurysms in vitro and in vivo.

METHODS

Using a recirculating pulsatile in vitro flow model, 5 different aneurysm geometries (inner/outer curve, narrow/wide neck, and fusiform) were treated (each n = 1) by flow-diverting stent (FDS) implantation and subsequent embolization through a jailed microcatheter using calibrated microspheres (500-900 μm) larger than the pores of the FDS mesh. Treatment effects were analyzed angiographically and by micro computed tomography. The fluid of the in vitro model was filtered to ensure that no microspheres evaded the aneurysm. The experiment was repeated once in vivo.

RESULTS

In vitro, all 5 aneurysms were safely and completely occluded by FDS-assisted microsphere embolization. Virtually complete aneurysm occlusion was confirmed by angiography and micro computed tomography. No microspheres escaped into the circulation. The experiment was successfully repeated in 1 pig with a sidewall aneurysm generated by vessel occlusion. An embolic protection system placed distally of the FDS in vitro and in vivo (each n = 1) contained no microspheres after the embolization. Thus, no microspheres were lost in the circulation, and the use of an embolic protection system seems feasible to provide additional safety.

CONCLUSION

FDS-assisted microsphere embolization of fusiform and sidewall aneurysms is feasible and yields virtually complete aneurysm occlusion while avoiding coil-associated beam-hardening artifacts.

Abstract 4458: The HIV-derived protein Vpr52-96 has anti-glioma activity in vitro and in vivo

Background: Patients with actively replicating human immunodeficiency virus (HIV) are highly radiosensitive and exhibit adverse reactions even at low irradiation doses. A major underlying cause is high intra- and extracellular levels of a virus-encoded peptide termed viral protein R (Vpr). As Vpr efficiently crosses the blood-brain barrier and accumulates in astrocytes, we examined whether it may be utilized as a drug in the treatment of glioblastoma multiforme (GBM).

Methods: Four glioblastoma-derived cell lines with and without lentivirus-mediated Methylguanine-DNA methyltransferase (MGMT) overexpression (U251, U87, U251-MGMT, U87-MGMT) were exposed to Vpr, temozolomide (TMZ), conventional photon irradiation (2-6 Gy) or to combinations. Caspase assays were employed to detect apoptosis. Colony formation assays were used to analyse clonogenic survival. Dose escalation was performed using n = 12 NOD/SCID/γc−/− (NSG) mice in a classical 3+3 manner. This strain was also used as an orthotopic implant model of glioma using luciferase-expressing U87 cells (n = 18). Continuous Vpr administration was achieved using osmotic pumps, irradiation (3×5 Gy) was performed using a small-animal irradiation device and intracerebral tumor growth was monitored using repetitive contrast-enhanced micro CT scans.

Results: Vpr showed high rates of acute toxicities with a LD50 of 4.0±1.1 μM for U251 and a LD50 of 15.7±7.5 μM for U87 cells. Caspase assays revealed Vpr-induced apoptosis in U251 but not in U87 cells. Vpr also efficiently inhibited clonogenic survival both in U251 and U87 cells and showed additive effects with irradiation. In contrast to TMZ, Vpr acted independently of the MGMT expression status. Dose escalation in mice (n = 12) was feasible and resulted in no evident renal or liver toxicity. Similar to irradiation with 3 × 5 Gy (n = 8), Vpr treatment of orthotopically implanted NSG mice (n = 5) delayed tumor growth and significantly (p = 0.041; log-rank test) prolonged overall survival compared to untreated animals (n = 5).

Conclusion: The HIV-encoded peptide Vpr exhibits all properties of an effective chemotherapeutic drug and may be a useful agent in the treatment of GBM.

Citation Format: Jens Kuebler, Stefanie Kirschner, Linda Hartmann, Grit Welzel, Maren Engelhardt, Carsten Herskind, Marlon R. Veldwijk, Christian Schultz, Manuela Felix, Gerhard Glatting, Patrick Maier, Frederik Wenz, Marc A. Brockmann, Frank A. Giordano. The HIV-derived protein Vpr52-96 has anti-glioma activity in vitro and in vivo. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4458. doi:10.1158/1538-7445.AM2015-4458

Minimally Invasive Monitoring of Chronic Central Venous Catheter Patency in Mice Using Digital Subtraction Angiography (DSA)

Background

Repetitive administration of medication or contrast agents is frequently performed in mice. The introduction of vascular access mini-ports (VAMP) for mice allows long-term vascular catheterization, hereby eliminating the need for repeated vessel puncture. With catheter occlusion being the most commonly reported complication of chronic jugular vein catheterization, we tested whether digital subtraction angiography (DSA) can be utilized to evaluate VAMP patency in mice.

Methods

Twenty-three mice underwent catheterization of the jugular vein and subcutaneous implantation of a VAMP. The VAMP was flushed every second day with 50 μL of heparinized saline solution (25 IU/ml). DSA was performed during injection of 100 μL of an iodine based contrast agent using an industrial X-ray inspection system intraoperatively, as well as 7±2 and 14±2 days post implantation.

Results

DSA allowed localization of catheter tip position, to rule out dislocation, kinking or occlusion of a microcatheter, and to evaluate parent vessel patency. In addition, we observed different ante- and retrograde collateral flow patterns in case of jugular vein occlusion. More exactly, 30% of animals showed parent vessel occlusion after 7±2 days in our setting. At this time point, nevertheless, all VAMPs verified intravascular contrast administration. After 14±2 days, intravascular contrast injection was verified in 70% of the implanted VAMPs, whereas at this point of time 5 animals had died or were sacrificed and in 2 mice parent vessel occlusion hampered intravascular contrast injection. Notably, no occlusion of the catheter itself was observed.

Conclusion

From our observations we conclude DSA to be a fast and valuable minimally invasive tool for investigation of catheter and parent vessel patency and for anatomical studies of collateral blood flow in animals as small as mice.

Similar stability and range of motion between cruciate-retaining and cruciate-substituting ultracongruent insert total knee arthroplasty

PURPOSE

The use of an ultracongruent (UC) insert with a standard femoral component for substitution of the posterior cruciate ligament (PCL) is a bone-preserving and therefore interesting alternative to the established box and cam mechanism of posterior-stabilized total knee arthroplasty (TKA). Despite the regular use of these UC inserts, there is little evidence about stability and range of motion (ROM).

METHODS

The aim of this study was to evaluate the stability and ROM in standard cruciate-retaining (CR) and cruciate-substituting UC inserts of the same TKA. In 39 patients, intraoperative measurements of stability and ROM were taken (1) before soft tissue release and bone cuts, (2) after implantation of a CR TKA and (3) after resection of the PCL and substitution with an UC insert. All measurements were taken using a navigation system.

RESULTS

Stability measurements demonstrated no differences between CR (PCL intact) and UC TKA (PCL resected), but significantly increased anteroposterior translation at 60° and 90° of knee flexion compared with the preoperative condition. ROM measurements demonstrated improvement of knee flexion from preoperatively mean 105° (SD 14.1°) to intraoperative 120.2° (SD 6.7°) with the CR and 121.0° (SD 7.5°) with the UC insert and 113.5° (SD 14.0°) at the 1-year follow-up.

CONCLUSION

This study demonstrates similar stability of an UC insert compared with a standard CR insert. UC inserts are therefore a bone-preserving solution if the PCL needs to be substituted. ROM was not improved after resection of the PCL and substitution with the UC insert.

LEVEL OF EVIDENCE

II.

Image-Guided Radiotherapy Using a Modified Industrial Micro-CT for Preclinical Applications

Purpose/Objective

Although radiotherapy is a key component of cancer treatment, its implementation into pre-clinical in vivo models with relatively small target volumes is frequently omitted either due to technical complexity or expected side effects hampering long-term observational studies. We here demonstrate how an affordable industrial micro-CT can be converted into a small animal IGRT device at very low costs. We also demonstrate the proof of principle for the case of partial brain irradiation of mice carrying orthotopic glioblastoma implants.

Methods/Materials

A commercially available micro-CT originally designed for non-destructive material analysis was used. It consists of a CNC manipulator, a transmission X-ray tube (10–160 kV) and a flat-panel detector, which was used together with custom-made steel collimators (1–5 mm aperture size). For radiation field characterization, an ionization chamber, water-equivalent slab phantoms and radiochromic films were used. A treatment planning tool was implemented using a C++ application. For proof of principle, NOD/SCID/γc^−/− mice were orthotopically implanted with U87MG high-grade glioma cells and irradiated using the novel setup.

Results

The overall symmetry of the radiation field at 150 kV was 1.04±0.02%. The flatness was 4.99±0.63% and the penumbra widths were between 0.14 mm and 0.51 mm. The full width at half maximum (FWHM) ranged from 1.97 to 9.99 mm depending on the collimator aperture size. The dose depth curve along the central axis followed a typical shape of keV photons. Dose rates measured were 10.7 mGy/s in 1 mm and 7.6 mGy/s in 5 mm depth (5 mm collimator aperture size). Treatment of mice with a single dose of 10 Gy was tolerated well and resulted in central tumor necrosis consistent with therapeutic efficacy.

Conclusion

A conventional industrial micro-CT can be easily modified to allow effective small animal IGRT even of critical target volumes such as the brain.

In vivo micro-CT imaging of untreated and irradiated orthotopic glioblastoma xenografts in mice: capabilities, limitations and a comparison with bioluminescence imaging

Small animal imaging is of increasing relevance in biomedical research. Studies systematically assessing the diagnostic accuracy of contrast-enhanced in vivo micro-CT of orthotopic glioma xenografts in mice do not exist. NOD/SCID/γc(-/-) mice (n = 27) underwent intracerebral implantation of 2.5 × 10(6) GFP-Luciferase-transduced U87MG cells. Mice underwent bioluminescence imaging (BLI) to detect tumor growth and afterwards repeated contrast-enhanced (300 µl Iomeprol i.v.) micro-CT imaging (80 kV, 75 µAs, 360° rotation, 1,000 projections, 33 s scan time, resolution 40 × 40 × 53 µm, 0.5 Gy/scan). Presence of tumors, tumor diameter and tumor volume in micro-CT were rated by two independent readers. Results were compared with histological analyses. Six mice with tumors confirmed by micro-CT received fractionated irradiation (3 × 5 Gy every other day) using the micro-CT (5 mm pencil beam geometry). Repeated micro-CT scans were tolerated well. Tumor engraftment rate was 74 % (n = 20). In micro-CT, mean tumor volume was 30 ± 33 mm(3), and the smallest detectable tumor measured 360 × 620 µm. The inter-rater agreement (n = 51 micro-CT scans) for the item tumor yes/no was excellent (Spearman-Rho = 0.862, p < 0.001). Sensitivity and specificity of micro-CT were 0.95 and 0.71, respectively (PPV = 0.91, NPV = 0.83). BLI on day 21 after tumor implantation had a sensitivity and specificity of 0.90 and 1.0, respectively (PPV = 1.0, NPV = 0.5). Maximum tumor diameter and volume in micro-CT and histology correlated excellently (tumor diameter: 0.929, p < 0.001; tumor volume: 0.969, p < 0.001, n = 17). Irradiated animals showed a large central tumor necrosis. Longitudinal contrast enhanced micro-CT imaging of brain tumor growth in live mice is feasible at high sensitivity levels and with excellent inter-rater agreement and allows visualization of radiation effects.

[Complications of metal-on-metal tribological pairing]

BACKGROUND

Metal-on-metal (MoM) tribological pairing results in less volumetric abrasion than pairing with the conventionally used polyethylene and is associated with a lower risk of material failure compared to other hard-hard pairings. An increased frequency of problem cases in recent years has led to a great increase in uncertainty. Against this background in this article the current aspects of epidemiology, etiology, diagnostics and treatment of complications in MoM hip joint endoprostheses will be discussed.

EPIDEMIOLOGY AND ETIOLOGY

Based on the results from national endoprosthesis registers and selected clinical studies an evaluation of the rate of local complications from MoM tribological pairings was undertaken. A differentiation was made between MoM pairings in pedicled small head prostheses (≤ 32 mm), large head (> 32 mm) and surface replacement (OFE) endoprostheses. Each year MoM endoprostheses release on average 10(12)-10(14) cobalt (Co) and chromium (Cr) nanoparticles per patient. This release of metal ions and particles can lead to a variety of tissue reactions.

DIAGNOSTICS

A differentiation must be made between regular routine diagnostics within the framework of implant follow-up screening and specific investigations due to the occurrence of complaints. The diagnostics for patients treated with MoM hip endoprostheses consists of a standardized step-wise approach considering possible differential diagnoses and the utilization of modern laboratory chemical and radiological methods. When problems occur, a differentiation should preferentially be made between complaints not caused by metal and mechanical problems (e.g. prosthesis loosening and impingement) and symptoms due to periprosthetic infections.

THERAPY OF COMPLICATIONS

The normal standards for hip endoprosthetics are also valid for periprosthetic infections, fractures and other general complications. Specific measures are, however, necessary for complications due to metal-specific risks.

[Endoprosthetic treatment of osteoporosis-related coxarthrosis : aspects of safe patient treatment]

BACKGROUND

With increasing life expectancy the prevalence of osteoarthritis is also substantially rising. Patients aged between 65 and 75 years scheduled for total joint arthroplasty suffer from undetected osteoporosis in 20-25% of cases.

OBJECTIVES

How to determine osteoporosis during preoperative workup? Which conclusions can be drawn for the operation treatment and the postoperative course?

METHODS

The literature dealing with the prevalence of osteoporosis, perioperative complications of total hip arthroplasty, selected register informations, guidelines for diagnostics and treatment of osteoporosis and for the postoperative treatment are summarized and discussed.

RESULTS

The fracture risk is determined according to the guidelines of the Dachverband Osteologie (DVO, Governing Body on Osteology). The implant and the anchorage are selected based on the risk of suffering from osteoporosis. An intraoperative fracture and early aseptic loosening are the main operative risk factors. For the postoperative course in addition to education about arthroplasty, adequate support for prevention of falls is mandatory. Continuous physiotherapy with muscular strengthening is advisable. The long-term medication should be checked for risks in the PRISCUS list of potentially inappropriate medication in the elderly and non-steroidal anti-inflammatory drugs (NSAIDs) should not be prescribed in patients with cardiac comorbidities. Patients with confirmed osteoporosis should be treated with antiresorptive agents.

[Minimally invasive surgery for knee total arthroplasty - evidence-based advantages?]

The impact of minimally invasive surgical techniques for implantation of a total knee arthroplasty is evaluated according to evidence-based medicine criteria. The patient-relevant clinical question can be formulated as: Is the rehabilitation of osteoarthritis patients with minimally invasive implantation of total knee arthroplasty faster compared to those with the conventional approach. The available literature is sorted and critically appraised with regard to methodological quality and risk of bias. Following the results of the meta-analyses the clinical question can be positively answered. Following the aspect of a structured evolution for surgical techniques, the meaning of a minimally invasive technique for total knee arthroplasty cannot be answered finally. Under the impression of more frequent surgical complications, the rating of the procedure is conservative. A general advantage is not apparent. Further studies investigating surgical learning curves, proper patient selection and the selection of the patient for such techniques are required, before the final judgement on the use of this technique can be formed.

[Re-evaluation of the AOK hospital navigator with a focus on total knee replacement]

BACKGROUND

One of the biggest health insurance companies in Germany (AOK, Allgemeine Ortskrankenkasse) has published new results focussing on process quality of total knee replacement in 2010. These results were published in the online portal "Weiße Liste", which is based on health insurance routine data. The German Association of Orthopeadic Surgery questions the credibility of the rating system of the "Weiße Liste". To prove the system an interdisciplinary task force was created.

MATERIAL AND METHODS

The task force identified patient-specific parameters, which influence the outcome of total knee replacement based on the literature and expert opinions. Out of 907 orthopaedic departments, 4 above average and four below average were identified. The AOK was asked to provide 80 data sets for each department. These anonymised data sets could be converted into patient-specific data sets in the identified departments. Statistical analysis was performed to answer the question of whether there are differences between the below and the above average groups.

RESULTS

625 cases could be investigated. We found an increased rate of postoperative complications in the below average group. There are differences between both groups in terms of factors influencing the procedure. In the below average group an increased rate of patients with one or more comorbidities and a preoperative extension lag of over 10° was found. The above average group has a higher rate of operations before the knee replacement.

CONCLUSION

The results need to be proven on a larger scale. Further, prospective investigations are planned.

[Femoral nerve palsy as delayed complication after total hip replacement: delayed hematoma formation in unexpected screw malpositioning]

Nerve injury after total hip replacement is a rare but severe complication. If the nerve lesion becomes evident in the early postoperative phase the lesion is often due to an incorrect implant position, direct nerve injury or vascular injury with manifestation of a hematoma which results in nerve compression. Secondary nerve lesions are more often due to a chronic hematoma with nerve compression. Secondary nerve lesions in particular are often a diagnostic challenge and should lead to an early revision after comprehensive imaging diagnostics.

Clinical benefit and cost effectiveness of total knee arthroplasty in the older patient

Purpose

Total knee arthroplasty (TKA) is an effective, but also cost-intensive health care procedure for the elderly. Furthermore, bearing demographic changes in Western Europe in mind, TKA-associated financial investment for health care insurers will increase notably and thereby catalyze discussions on ressource allocation to Orthopedic surgery. To derive a quantitative rationale for such discussions within Western Europe's health care systems, a prospective assessment of both the benefit of TKA from a patient's perspective as well as its cost effectiveness from a health care insurer's perspective was implemented.

Methods

A prospective cost effectiveness trial recruited a total of 65 patients (60% females), who underwent TKA in 2006; median age of patients was 66 years (interquartile range 61 - 74 years). Before and three months after surgery patients were interviewed by means of the EuroQol-5D and the WOMAC questionnaires to assess their individual benefit due to TKA and the subsequent inpatient rehabilitation. Both questionnaires' benefit estimates were transformed into the number of gained quality adjusted life years [QALYs]. Total direct cost estimates for the overall care were based on German DRG and rehabilitation cost rates [€]. The primary clinical endpoint of the investigation was the individual number of QALYs gained by TKA based on the WOMAC interview; the primary health economic endpoint was the marginal cost effectiveness ratio (MCER) relating the costs to the associated gain in quality of life [€/QALY].

Results

Total direct costs for the overall procedure were estimed 9549 € in median. The WOMAC based interview revealed an overall gain of 4.59 QALYs (interquartile range 2.39 - 6.21 QALYs), resulting in marginal costs of 1795 €/QALY (1488 - 3288 €/QALY). The corresponding EuroQol based estimates were 2.93 QALYs (1.75 - 5.59 QALYs) and 3063 €/QALY (1613 - 5291 €/QALY). Logistic regression modelling identified the patients' age as the primary determinant of cost effectiveness (Likelihood Ratio p = 0.006): patients younger than 60 years showed a median gain of 6.45 QALYs and median marginal costs of 1463 €/QALY, patients between 60 - 70 years 5.47 QALYs and 1744 €/QALY, patients older than 70 years 2.76 QALYs and 3186 €/QALY.

Conclusion

TKA was proven to be cost effective from a health care insurer's perspective, although its marginal costs notably increased with increasing age. Note, however, that this age-related gradient in marginal cost effectiveness is of comparable order as the changes in cost effectiveness due to variation of the underlying assessment instrument.

[The EbM Commentary at the Annual Meeting of the German Congress of Orthopaedics and Traumatology (DKOU): background, aims and vision]

The critical appraisal of clinical and scientific work to assure the effectiveness and to balance the risks of treatment are mandatory today. Recent innovations in medicine often lead only to minor improvement in patient benefit. For the better understanding of the presented study results, the EbM commentary was introduced in 2007 at the Annual Meeting of the German Society of Orthopaedics and Traumatology. The EbM commentary was developed within the Swiss Orthopaedic Society and is a vital part of the Annual Meetings. The EbM commentary is a carefully prepared critical appraisal of an orally presented study by a specially trained colleague. The commentary consists of three components and begins with a systematic analysis following the SPION principle. What kind of study was carried out? Which patients were enrolled in the investigation? What kind of interventions were compared? How was the outcome measured? What is the benefit of the study for my own practice and what is the benefit for the patient? The reporting and the evaluation of the patient benefit is of great interest. In the second step the strengths and weaknesses of the study were discussed and the study will be rated for their evidence. For the best case the presented study implies direct changes in the usual treatment of patients. In the worst case no changes are necessary and the study is rated "so what" because of methodological weaknesses making the drawn conclusions invalid. For the audience the EbM commentary may support their rating of the quality of the presented study. The congress team selects interesting presentations for the EbM commentary. The EbM commentators receive the oral presentation and in most cases additional information from the selected studies four weeks in advance of the meeting. The EbM commentary is focused on a precise analysis of the presented data in an open and pleasant discussion. The aim of the EbM commentary is to clearly point out the patient benefit and to disclose the biases and weaknesses. The best studies of the DKOU were awarded following the suggestion of the EbM jury. The experiences have shown some methodological improvement of the presentations. The pragmatic style of the EbM commentary has led to good acceptance at the Annual Meeting of the German Society of Orthopaedics and Traumatology.

[Avoidance, diagnostics and therapy of nerve lesions after total hip arthroplasty]

Nerve palsy following total hip arthroplasty is a rare complication. Developmental dysplasia of the hip, previous fracture treatment and medical comorbidities are characteristic risk factors. By accurate preparation of the patient and a careful operative technique nerve palsy can be avoided in most cases. Nerve palsy following poor patient positioning during the perioperative period should be avoided by close cooperation with anesthesiologists.In cases of postoperative nerve palsy correct diagnostics should be carried out immediately. Further treatment options should be considered to minimize the damage. For patients with definite nerve palsy, devices such as a foot drop splint are often necessary and should be carried out as soon as possible.

[Clinical pathway "total knee arthroplasty"]

Total knee arthroplasty is a standardized intervention in orthopedic departments. Due to the standard character of the procedure it is predestinated to be performed in a clinical pathway. We developed a clinical pathway for total knee arthroplasty and aim to show the details of it and discuss it together with the current literature. Total knee arthroplasty is a standardized procedure and is therefore predestinated to be included in a clinical pathway. The team consists of different groups which are combined in this path to work together in a very structured and standardized manner. We describe and discuss our clinical pathway for total knee arthroplasty and the initial experiences which are very promising.

Social, educational, and occupational predictors of total hip replacement outcome

OBJECTIVE

There is limited evidence on social, educational, and occupational factors as predictors of response to total hip replacement (THR). We aimed to analyze these factors in a large population-based setting.

METHOD

Patients of the Dresden Hip Surgery Registry were recruited and the pre and post (6 months) operative functional status was assessed using the global Western Ontario and McMasters Universities Osteoarthritis Index (WOMAC) score (0-100 points). Non-response was defined a gain of <20 points in WOMAC score over a 6 months period and was analyzed with respect to six socioeconomic parameters. Multiple logistic regression modeling was applied to adjust for age, sex, BMI, co-morbidity, and preoperative functional status.

RESULTS

Data from 1007 patients (mean age 61 years, STD 13; 55% women) were included. The average preoperative WOMAC score was 45.8 which increased to 84.4 after surgery. 38.2%, 36.6%, and 25.3% of the patients attended school for 8, 9, and 12 years, respectively. 54.1% were retired, 26.9% worked full time, and 6.7% received a disability pension. A 14.8% of the patients did not achieve a gain of > or =20 points in WOMAC score and were classified as non-responders. After control for confounders, significantly increased risks of non-response were found for widowed patients compared to singles [odds ratio (OR) 4.30, 1.45-12.71], those who lived alone (OR 1.70, 1.02-2.85), and patients with a disability pension compared to those who worked full time (OR 5.81, 2.33-14.46). The risk of non-response decreased with increasing length of school education (12 vs 8 years: OR 0.49, 0.27-0.89). Compared to workers, employees (OR 0.55, 0.33-0.90) and self-employed patients (OR 0.41, 0.18-0.94) showed significantly decreased risks of non-response.

CONCLUSION

Socioeconomic parameters are independent predictors of response to THR. This can help to improve the health service by identifying subgroups which need special attention in order to increase the response rate.

Precision of navigated and conventional open-wedge high tibial osteotomy in a cadaver study

High tibial osteotomy (HTO) is an established treatment option for isolated medial osteoarthritis in young and active patients. One important factor for success of this procedure is the degree of correction of the weight-bearing line. Computer-assisted navigation systems are believed to improve the precision of axis correction through intraoperative real-time monitoring. This study investigates the precision of correction of the weight-bearing line in open-wedge HTO with and without a navigation system.

Nineteen legs of well-preserved human cadaver were randomly assigned to navigated (n = 10) or conventional (n = 9) HTO. In order to achieve a sufficient amount of correction in all legs the weight-bearing line was aimed at 80 percent of the width of the tibial plateau.

The mean deviation of the weight-bearing line from the desired 80 percent was 1 percent in the navigated and 8.6 percent in the conventional operated legs (p = 0.002). The weight-bearing line of all navigated but only 5 of the 9 conventional operated legs was within a ± 5 percent tolerance level (p = 0.33).

Navigated open-wedge HTO achieved better correction of the weight-bearing line than the conventional method in human cadaver legs. Future studies have to prove this advantage in a clinical setting and it's effect on patient outcome.

Reliability of limb alignment measurement for high tibial osteotomy with a navigation system

Objective

High tibial osteotomy (HTO) is one treatment option for young and active patients with unicompartmental osteoarthritis. The success of this procedure substantially depends on the degree of correction of the mechanical axis. Computer-assisted navigation systems are believed to improve the precision of axis correction through intraoperative real-time monitoring. This study investigates the accuracy of limb alignment measurements with a navigation system on a cadaver specimen.

Materials and methods

The measurements were performed on a well-preserved cadaver specimen with a mechanical leg axis of 4° varus. Data was collected during the HTO workflow. Repeated serial measurements were undertaken by four different surgeons. After these measurements, different landmarks were deliberately set at the wrong place to examine the influence of mistakes during registration.

Results

There was a high intra-and interobserver reliability with a mean mechanical leg axis of 3.9° ± 0.7° and a mean error of 0.6°. The grossly incorrect placement of landmarks for knee and ankle center resulted in an incorrect mechanical leg axis of 1° valgus up to 10° varus.

Conclusion

The computer-assisted navigation system provided precise information about the mechanical leg axis, irrespective of the observer's experience.

EULAR evidence-based recommendations for the diagnosis of knee osteoarthritis

Objective

To develop evidence-based recommendations for the diagnosis of knee osteoarthritis (OA).

Methods

The multidisciplinary guideline development group, representing 12 European countries, generated 10 key propositions regarding diagnosis using a Delphi consensus approach. For each recommendation, research evidence was searched systematically. Whenever possible, the sensitivity, specificity and likelihood ratio were calculated for individual diagnostic indicators and a diagnostic ladder was developed using Bayes' method. Secondary analyses were undertaken to test directly the recommendations using multiple predictive models in two populations from the UK and the Netherlands. Strength of recommendation was assessed by the EULAR visual analogue scale.

Results

Recommendations covered the definition of knee OA and its risk factors, subsets, typical symptoms and signs, the use of imaging and laboratory tests and differential diagnosis. Three symptoms (persistent knee pain, limited morning stiffness and reduced function) and three signs (crepitus, restricted movement and bony enlargement) appeared to be the most useful. Assuming a 12.5% background prevalence of knee OA in adults aged ≥45 years, the estimated probability of having radiographic knee OA increased with increasing number of positive features, to 99% when all six symptoms and signs were present. The performance of the recommendations in the study populations varied according to the definition of knee OA, background risk and number of tests applied.

Conclusion

10 key recommendations for diagnosis of knee OA were developed using both research evidence and expert consensus. Although there is no agreed reference standard, thorough clinical assessment alone can provide a confident rule-in diagnosis.

[Implementation of standardized postoperative pain therapy for orthopaedic patients. Comparison between unsystematic and standardized pain therapy]

BACKGROUND

The painless clinic and postoperative pain therapy are currently major issues in the management of surgical procedures. The aim of this study was to evaluate the benefit of a standardized pain therapy on the postoperative pain level after orthopaedic procedures.

PATIENTS AND METHODS

We investigated two different groups of patients who underwent an orthopaedic surgical procedure. Group 1 (n = 249) received a pain therapy which was based on an individual and surgery-dependent concept whereas group 2 (n = 243) was treated with a standardized pain therapy concept. The effect of the treatment was monitored with a VAS-based protocol.

RESULTS

Up to day 9 after surgery there was a significant difference between the two groups in regard to the postoperative pain. The patients of group 2 had less pain but had more unwanted side effects caused by the pain therapy during the first 3 days after surgery. Mobility and mental disposition were positively affected.

CONCLUSION

The implementation of a standardized pain therapy is successful in reducing postoperative pain. Mobility and mental disposition are also influenced positively. As a consequence the incidence of unwanted side effects is rising.

Midterm results following revision surgery in clubfeet

Relapse rates of surgically treated clubfeet are about 25%. We reviewed 43 patients (57 feet) treated for relapsed clubfoot deformity between 1992 and 2001 in our department. The average age of the patients at the time of revision surgery was 5.1 years, the mean follow-up was 6.6 years. Surgical therapy was performed using an algorithm according to age groups. The mean Atar score at follow-up was 77 points, representing a good outcome. Out of 57 feet, 20 (35%) were rated excellent, 24 (42%) good, 5 (9%) fair, and 8 (14%) poor. The number of previous surgical interventions had no influence on the outcome. Using an age related surgical algorithm, good postoperative results could be achieved in most of our patients, thus improving their functional situation. This emphasises the usefulness of the proposed algorithm in the difficult situation of recurrent clubfoot, while thorough analysis of the underlying deformity remains essential.

Fuctional outcome after open and arthroscopic bankart repair for traumatic shoulder instability

Purpose

Both open and arthroscopic Bankart repair are established procedures in the treatment of anterior shoulder instability. While the open procedure is still considered as the "golden standard" functional outcome is supposed to be better in the arthroscopic procedure. The aim of this retrospective study was to compare the functional outcome between open and arthroscopic Bankart repair.

Materials and methods

In 199 patients a Bankart procedure with suture anchors was performed, either arthroscopically in presence of an detached, but not elongated capsulolabral complex (40) or open (159). After a median time of 31 months (12 to 67 months) 174 patients were contacted and agreed to follow-up, 135 after open and 39 after arthroscopic Bankart procedure.

Results

Re-dislocations occurred in 8% after open and 15% after arthroscopic Bankart procedure. After open surgery 4 of the 11 re-dislocations occurred after a new adequate trauma and 1 of the 6 re-dislocations after arthroscopic surgery. Re-dislocations after arthroscopic procedure occured earlier than after open Bankart repair. An external rotation lag of 20° or more was observed more often (16%) after open than after arthroscopic surgery (3%). The Rowe score demonstrated "good" or "excellent" functional results in 87% after open and in 80% patients after arthroscopic treatment.

Conclusion

In this retrospective investigation the open Bankart procedure demonstrated good functional results. The arthroscopic treatment without capsular shift resulted in a better range of motion, but showed a tendency towards more frequently and earlier recurrence of instability. Sensitive patient selection for arthroscopic Bankart repair is recommended especially in patients with more than five dislocations.

Allergenicity of wine containing processing aids: a double-blind, placebo-controlled food challenge

BACKGROUND

The European Union requires allergenic food ingredients to appear on labels in order to protect allergic consumers.

OBJECTIVE

To determine whether traces of egg-, milk-, and fish-derived processing aids used in winemaking might elicit clinical reactions in food-allergic patients.

METHODS

Five German wines were fined with a high dose of egg albumin, lysozyme, milk casein, fish gelatin, or isinglass, and filtered. Fourteen adults with allergy to egg (n = 5), milk (n = 5), or fish (n = 4) were included. Skin prick tests were performed with fining agents, and fined and unfined wines. All patients underwent double-blind placebo-controlled food challenges with fined and unfined wines.

RESULTS

Skin prick tests were positive to hen's egg (n = 5), ovalbumin (n = 5), lysozyme (n = 4), cow's milk (n = 5), casein (n = 4), and cod (n = 3), but not to isinglass or fish gelatin (n = 0). Positive skin prick test results were observed for wines fined with albumin (n = 3), lysozyme (n = 2), casein (n = 1), gelatin (n = 0), and isinglass (n = 3), and for unfined wines (n = 1-2 in each patient group), with no significant differences between groups. Seventy-five percent of skin test-positive patients had specific immunoglobulin E to other allergens present in wine (eg, carbohydrates). The provocation test revealed no reactions to fined or unfined wines.

CONCLUSIONS

Although concentrated fining agents containing ovalbumin, lysozyme, and casein were allergenic in the skin prick test, no patient reacted adversely in the provocation test to fined wine. Wines treated with fining agents at commercial concentrations appear not to present a risk to allergic individuals when filtered,

[A rare coagulation disorder. Diagnostics and management in cases of hereditary dysfibrinogenemia]

Before elective surgery, it is mandatory that a precise history be taken to detect increased hemorrhagic diathesis and that thrombocytes, Quick/INR, and aPTT be determined. If pathological levels are found, further laboratory tests are necessary after frequent causes (e.g., liver cirrhosis) have been excluded. Single-factor analysis for the von Willebrand's factor antigen and if necessary further tests to check for von Willebrand's syndrome (multimeric analysis) as well as platelet function tests should be performed.Dysfibrinogenemia is a rare coagulation disorder, which causes elevated INR. It shows a wide spectrum of clinical manifestations including thrombophilia, excessive bleeding, and even asymptomatic cases. We present a 72-year-old patient with asymptomatic dysfibrinogenemia who needed hip replacement due to arthrosis. Lowered fibrinogen levels were substituted prior to operation and the clinical course afterwards was uneventful under additional prophylactic anticoagulation in order to prevent thrombosis. The case report illustrates the interdisciplinary teamwork which is very important in the management of patients with coagulation disorders.

Computer-assisted and conventional total knee replacement: a comparative, prospective, randomised study with radiological and CT evaluation

After obtaining informed consent, 80 patients were randomised to undergo a navigated or conventional total knee replacement. All received a cemented, unconstrained, cruciate-retaining implant with a rotating platform. Full-length standing and lateral radiographs and CT scans of the hip, knee and ankle joint were carried out five to seven days after operation. No notable differences were found between computer-assisted navigation and conventional implantation techniques as regards the rotational alignment of the femoral or tibial components. Although the deviation from the transepicondylar axis was relatively low, there was a considerable range of deviation for the tibial rotational alignment. There was no statistically significant difference regarding the occurrence pattern of outliers in mechanical malalignment but the number of outliers was reduced in the navigated group.