Not applicable.
The study was carried out as part of a non-commercial cooperation.

The protocol follows guidelines of the Human Research Ethics Committee of the Medical University of Warsaw. The patient gave informed consent to the procedure and acknowledged the fact that it will be recorded. The patient agreed to that prior to the procedure.
NOTE: The basic criterion for including the patient in the surgery project was the necessity to intervene because of the anatomical dysfunction, which made it impossible to use a standard implant. Mixed reality was aimed at better placement of the prosthesis, increasing the chances of successful surgery.
1. Preparation
<ol>
	<li>Prepare a custom-made acetabular implant and plan the surgical procedure before the patient&#39;s hospitalization. 
	NOTE: In this case study, persons skilled in the art of medical image diagnostics prepared the custom-made acetabular implant.
	<ol>
		<li>Before the planned admission to the hospital, perform an x-ray in the diagnostic imaging unit.</li>
		<li>Perform a pelvic X-ray in an anterior-posterior projection.</li>
		<li>Assess the current condition of the patient&#39;s pelvis based on the X-ray.</li>
		<li>Compare the image obtained with the earlier X-ray images.</li>
	</ol>
	</li>
	<li>Take a pelvic CT scan and acquire DICOM (Digital Imaging and Communications in Medicine) files according to the protocol.
	<ol>
		<li>Place the patient on the moveable CT scan platform.</li>
		<li>Click on the thickness button and select 512 x 512 px thickness for the scans.</li>
		<li>Click on the parameter that determines the thickness of the 1 mm layer.</li>
		<li>Start the procedure by clicking, wait for the test result.</li>
	</ol>
	</li>
	<li>Ask an engineer to design an implant proposal that can be sent digitally as a technical scheme, or a 3D printed model prototype (Figure 1).
	<ol>
		<li>Visualize the computed tomography result in the DICOM viewer.</li>
		<li>Determine the needs for the implementation of the implant, taking into account the current anatomical conditions of the patient, biomechanics, and the function of the joint.</li>
		<li>Consult the engineer for suggestions on implants, including fixation.</li>
		<li>Approve the project and wait for shipment. 
		NOTE: The final shape of the implant involves combining 3D data from a patient&#39;s CT scan with the input of a design engineer and a surgeon.</li>
	</ol>
	</li>
	<li>Print the custom-made 3D implant from the titanium alloy powder (TiAl6V4) using electron beam technology26,27. Inside a chamber containing small amounts of TiAl6V4 powder, each time the electron beam is fired, there is selective melting and accumulation of material (plasma coating).</li>
	<li>Check whether the implant was sterilized. Sterilization of implant trials and the final implant was guaranteed by the manufacturer.</li>
</ol>
2. Pre-surgery checkups
<ol>
	<li>Perform a standard of care laboratory tests and specialist consultations.
	<ol>
		<li>Exclude patients with potential periprosthetic joint infection (no radiological features, normal c-reactive protein (&#60;10 mg/L), and erythrocyte sedimentation rate of 1-10 mm/h for women, 3-15 mm/h for men).</li>
	</ol>
	</li>
	<li>Check for the clinical signs of infection such as fever (systemic), pain, swelling, redness (local), and reduced joint function28.
	<ol>
		<li>Exclude patients having signs of local inflammation during the clinical examinations (redness, temperature increase, pain, swelling and loss of function indicate local inflammation). The patient gave complete informed consent to the operation.</li>
	</ol>
	</li>
</ol>
3. Mixed reality model
NOTE: The process is performed to achieve proper implant and pelvis visualization, which will be used intraoperatively.
<ol>
	<li>Process the pelvic CT DICOM file into a holographic representation using dedicated application.
	<ol>
		<li>Load the CT image into mixed reality headset from acquired CT DICOM files.
		<ol>
			<li>Open holographic DICOM Viewer.</li>
			<li>Select the folder containing CT DICOM files.</li>
			<li>Check the IP that is displayed when the headset is switched on and enter it in a designated place in the holographic DICOM Viewer.</li>
			<li>Click on the Connect button to be able to see the visualization in the mixed reality headset.</li>
		</ol>
		</li>
		<li>Segment the pelvis bone tissue structures. This is performed manually by using the Scissors option. When the option is enabled, the user clicks the left mouse button and moves the mouse around to remove the structures that are selected with this tool.
		<ol>
			<li>End the selection with another click of the left mouse button, which creates a pop-up for the user to confirm that he/she wants to cut out the structures that are selected. 
			NOTE: The user can choose areas to be cut out from the visualization in both 3D and 2D views. It is possible to remove the structures from within or outside the selection. This is repeated until only the necessary parts of the CT image are visible.</li>
		</ol>
		</li>
		<li>Choose a predefined transfer function (color visualization parameters) dedicated to orthopedic procedures from the list of available functions by clicking on its name: CT Bone Endoprosthesis. If needed, adjust the visualization by changing the window and level using the right mouse button connected with mouse movement in the 3D visualization window.</li>
		<li>Connect to the headset to see the prepared visualization in the 3D holographic space. Adjust the image using voice commands: Rotate, Zoom, Cut Smart, and Hand Gestures.</li>
		<li>Use the Cut Smart command to use and adjust a cutting plane that is perpendicular to user&#39;s line of sight. The closer the user moves the head into the hologram, the deeper the plane goes.</li>
		<li>Perform these movements to see the inner parts of the visualization because structures that are located anteriorly to the plane are not visualized. 
		NOTE: This view is important to assess the geometrical relations between structures (pelvis, femur, and implant) (Figure 2 and Figure 3).</li>
	</ol>
	</li>
</ol>
4. Surgery
<ol>
	<li>Perform the surgical procedure of revision hip arthroplasty due to aseptic loosening of the acetabular component with the use of a custom-made acetabular implant and mixed reality device14,16,29. Use a scalpel, an electrosurgical knife with a coagulator, a Luer tool and cutters for the operation.
	<ol>
		<li>Give 1.5 g of ceftriaxone intravenously 30 min prior to the skin incision, and two subsequent doses are to be given on the day of the surgery to prevent infection. Initiate thromboprophylaxis on the day before the surgery with low molecular weight heparin (LMWH). Continue the single daily dose of 40 mg enoxaparin for 30 days after the procedure.</li>
		<li>Place and secure the patient under general anesthesia, lying down on the operating table.</li>
		<li>Release the connective tissue adhesions using the Hardinge access to the hip joint and remove the loose acetabular implant.</li>
		<li>Perform the operation in the same way as other revision procedures of the hip joint, but use a wider access.</li>
		<li>Remove all soft tissues from the surface of the acetabulum so that the shape is exactly the same as in the model provided. The implant model must perfectly adhere to the surface of the acetabular bone.</li>
		<li>Fix the new uncemented implant using specially designed screws that stabilize the implant.</li>
		<li>Perform a femoral nerve block after surgery.</li>
	</ol>
	</li>
	<li>Intraoperative holographic visualization of processed images
	<ol>
		<li>Load the visualization of the DICOM CT scan prepared in the pre-procedural planning to the mixed reality application.</li>
		<li>Connect the mixed reality headset to the mixed reality application to see the prepared visualization in the 3D holographic space.</li>
		<li>Use intraoperative holographic visualization of the processed images to achieve adequate and precise pelvic bone surface preparation as well as for removal of the excess of connective tissue that developed as a response to loosening of the acetabular component.</li>
		<li>Ensure that the operator looks at the holographic visualization as a reference image.</li>
		<li>Use a scalpel, an electrosurgical knife with a coagulator, a luer tool, and cutters for the operation. Visualization of the 3D pelvis model should minimize the risk of damaging neurovascular structures and mistakes in implant placement.</li>
		<li>Ensure that the head-mounted display is connected to the workstation through a WiFi network. The processing of the images and the rendering is performed on the workstation and the results are displayed on the headset as holograms. Use gestures and voice commands. If necessary, get help from an engineer with POV preview.</li>
	</ol>
	</li>
</ol>
5. Postoperative care
<ol>
	<li>Make the patient undergo a standard rehabilitation and recovery protocol, including rehabilitation and mobilization on the first day after surgery30,31,32. 
	NOTE: Rehabilitation was implemented by a dedicated team experienced in the hip and knee arthroplasty.</li>
	<li>Implement pharmacological thromboprophylaxis. Thromboprophylaxis was initiated on the day before the surgery with low molecular weight heparin (LMWH). The single daily dose of 40 mg enoxaparin was continued for 30 days after the procedure.</li>
</ol>

Maciej Stanuch, Adriana Z&#322;ahoda-Huzior and Andrzej Skalski are MedApp S.A. employees. MedApp S.A. is the company that manufactures the CarnaLifeHolo solution.

Primary and revision hip arthroplasty may require personalization to ensure effectiveness of treatment. However, the use of custom implants requires longer preparation for surgery compared to standard procedures. Custom-made 3D printed implants are the solution that gives a chance to restore function in non-typical patients whose disease has caused significant bone destruction29. Standard prostheses are insufficient due to advanced degenerative disease developing rapidly, bone defects caused by pr...

The technology of three-dimensional (3D) printing and visualization of complex structures is rapidly growing in various fields of medicine. These include cardiovascular surgery, otorhinolaryngology, maxillofacial surgery, and, above all, orthopedic surgery1,2,3,4,5. Currently, this technology is used in orthopedic surgery not only in the direct implementation of 3D printed elements, but also in surgical training, preoperative planning, or intraoperative navigation6,7,8.
Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are one of the most frequently performed orthopedic surgical procedures worldwide. Due to the significant improvement in the patient&#39;s quality of life, THA had been described in a previous publication as the &#34;surgery of the century&#34;9. In Poland, 49.937 THA and 30.615 TKA were performed in 201910. As life expectancy increases, there is an upward trend in the projected number of hip and knee arthroplasty surgeries. Great efforts have been made to improve implant design, surgical technique, and postoperative care. These advances led to a better chance of restoring patient function and reducing the risk of complications11,12,13,14.
However, the big challenge currently faced by orthopedic surgeons worldwide is working with non-standard patients whose anatomical defects in the hip joint make it very difficult or even impossible to implement an off-the-shelf implant15. Bone loss may be due to significant trauma, progressive degenerative osteoarthritis with an acetabular protrusion, developmental hip dysplasia, primary bone cancer, or metastasis16,17,18,19,20. The problem of implant selection specifically concerns patients who are at risk of multiple revisions, sometimes also requiring unconventional treatment. In such cases, a very promising solution is an additive-made 3D printed implant created for a specific patient and bone defect, allowing for a very precise anatomical fit20.
In the field of arthroplasty, precise implant and its sustainable fixation are crucial. Progress in preoperative and intraoperative 3D visualization has resulted in excellent solutions as augmented and mixed reality21,22,23,24. Intraoperative use of bone and implant computed tomography (CT) holograms may allow better prosthesis placement than conventional radiography images. This emerging technology may increase the chances of therapy effectiveness and reduce the risk of neurovascular complications21,25.
This case report concerns a patient subjected to hip revision surgery due to aseptic loosening. To address significant bone loss caused by multiple implant failures, the custom-made 3D printed acetabular implant was used. During the procedure, we used mixed reality to visualize the implant position to avoid damaging the at-risk neurovascular structures. Application implemented to mixed reality headset allows giving voice and gesture commands, making it possible to use it in sterile conditions during the surgical procedure.
A 57-year-old woman was admitted to the department with a preliminary diagnosis: loosening of the left hip&#39;s acetabular component. The patient&#39;s disease history was extensive. Throughout her life, she underwent numerous surgical procedures of the hip joint. The first treatment was hip resurfacing due to osteoarthritis caused by hip dysplasia (1977-15 years old), the second was a total hip arthroplasty due to implant loosening (1983-21 years old), and other two revision surgeries (1998, 2000-37 and 39 years old). Moreover, the patient was suffering from spastic left-sided hemiplegia caused by childhood cerebral palsy, and she was repeatedly operated due to left clubfoot deformity. She was also burdened with osteoarthritis of the thoracolumbar spine, carpal tunnel syndrome, and well-controlled arterial hypertension. The final diagnosis preceding the qualification for the next procedure was the pain and increasing function limitation caused by loosening of the left hip&#39;s acetabular component. The patient was highly motivated, physically active, and coping with disability.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>CarnaLifeHolo v. 1.5.2</td>
			<td>MedApp S.A.</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Custom-Made implant type Triflanged Acetabular Component</td>
			<td>BIOMET</td>
			<td>REF PM0001779</td>
			<td></td>
		</tr>
		<tr>
			<td>Head Constrained Modular Head + 9mm Neck for cone 12/14, Co-Cr-Mo, size 36mm</td>
			<td>BIOMET</td>
			<td>REF 14-107021</td>
			<td></td>
		</tr>
		<tr>
			<td>Polyethylene insert Freedom Ringloc-X Costrained Linear Ringloc-X 58mm for head 36mm / 10 *</td>
			<td>BIOMET</td>
			<td>REF 11-263658</td>
			<td></td>
		</tr>
	</tbody>
</table>

the use of mixed reality in custom-made revision hip arthroplasty: a first case report

The technology of 3D printing and visualization of anatomical structures is rapidly growing in various fields of medicine. A custom-made implant and mixed reality were used to perform complex revision hip arthroplasty in January 2019. The use of mixed reality allowed for a very good visualization of the structures and resulted in precise implant fixation. According to the authors' knowledge, this is the first described case report of the combined use of these two innovations. The diagnosis preceding the qualification for the procedure was the loosening of the left hip's acetabular component. Mixed reality headset and holograms prepared by engineers were used during the surgery. The operation was successful, and it was followed by early verticalization and patient rehabilitation. The team sees opportunities for technology development in joint arthroplasty, trauma, and orthopedic oncology.

Image preprocessing 
Binary masks of the pelvic bone, femur, and endoprosthesis were semi-automatically segmented from CT DICOM images by experienced radiologic technologists using thresholding and region growing algorithms with available software33. The prepared label maps were also manually corrected by a radiologist. Label maps were used to enhance the visualization by adding them to the CT scan in the next step. This approach made it possible to merge the volumetric rende...

Watch this Scientific Journal Video about The Use of Mixed Reality in Custom-Made Revision Hip Arthroplasty: A First Case Report at JoVE.com

The Use of Mixed Reality in Custom-Made Revision Hip Arthroplasty: A First Case Report

A complex revision hip arthroplasty was performed using a custom-made implant and mixed reality technology. According to the authors&#39; knowledge, this is the first report of such procedure described in the literature.

The technology of 3D printing and visualization of anatomical structures is rapidly growing in various fields of medicine. A custom-made implant and mixed ...

the-use-mixed-reality-custom-made-revision-hip-arthroplasty-first

Universidad de Cartagena UDEC

Research

JoVE Journal

Medicine

3.2K Views.  Medical University of Warsaw. A complex revision hip arthroplasty was performed using a custom-made implant and mixed reality technology. According to the authors' knowledge, this is the first report of such procedure described in the literature. 

Video: The Use of Mixed Reality in Custom-Made Revision Hip Arthroplasty: A First Case Report

Reverse Total Shoulder Arthroplasty

Reverse total shoulder arthroplasty was initially approved for use in rotator cuff arthropathy and well as chronic pseudoparalysis without arthritis in patients who were not appropriate for tendon transfer reconstructions. Traditional surgical options for these patients were limited and functional results were sub-optimal and at times catastrophic. The use of reverse shoulder arthroplasty has been found to effectively restore these patients function and relieve symptoms associated with their disease. The procedure can be done through two approaches, the deltopectoral or the superolateral. Complication rates associated with the use of the prosthesis have ranged from 8-60% with more recent reports trending lower as experienced is gained. Salvage options for a failed reverse shoulder prosthesis are limited and often have significant associated disability. Indications for the use of this prosthesis continue to be evaluated including its use for revision arthroplasty, proximal humeral fracture and tumor. Careful patient selection is essential because of the significant risks associated with the procedure.

Reverse total shoulder arthroplasty is indicated for the treatment of conditions that cannot be treated with conventional arthroplasty or other procedures. These primarily include degenerative and incapacitating conditions with irreparable rotator cuff and loss of the normal biomechanical coupling of the shoulder.

Reverse total shoulder arthroplasty was initially approved for use in rotator cuff arthropathy and well as chronic pseudoparalysis without arthritis in ...

In vivo Dual Substrate Bioluminescent Imaging

Our understanding of how and when breast cancer cells transit from established primary tumors to metastatic sites has increased at an exceptional rate since the advent of in vivo bioluminescent imaging technologies 1-3. Indeed, the ability to locate and quantify tumor growth longitudinally in a single cohort of animals to completion of the study as opposed to sacrificing individual groups of animals at specific assay times has revolutionized how researchers investigate breast cancer metastasis. Unfortunately, current methodologies preclude the real-time assessment of critical changes that transpire in cell signaling systems as breast cancer cells (i) evolve within primary tumors, (ii) disseminate throughout the body, and (iii) reinitiate proliferative programs at sites of a metastatic lesion. However, recent advancements in bioluminescent imaging now make it possible to simultaneously quantify specific spatiotemporal changes in gene expression as a function of tumor development and metastatic progression via the use of dual substrate luminescence reactions. To do so, researchers take advantage for two light-producing luciferase enzymes isolated from the firefly (Photinus pyralis) and sea pansy (Renilla reniformis), both of which react to mutually exclusive substrates that previously facilitated their wide-spread use in in vitro cell-based reporter gene assays 4. Here we demonstrate the in vivo utility of these two enzymes such that one luminescence reaction specifically marks the size and location of a developing tumor, while the second luminescent reaction serves as a means to visualize the activation status of specific signaling systems during distinct stages of tumor and metastasis development. Thus, the objectives of this study are two-fold. First, we will describe the steps necessary to construct dual bioluminescent reporter cell lines, as well as those needed to facilitate their use in visualizing the spatiotemporal regulation of gene expression during specific steps of the metastatic cascade. Using the 4T1 model of breast cancer metastasis, we show that the in vivo activity of a synthetic Smad Binding Element (SBE) promoter was decreased dramatically in pulmonary metastasis as compared to that measured in the primary tumor 4-6. Recently, breast cancer metastasis was shown to be regulated by changes within the primary tumor microenvironment and reactive stroma, including those occurring in fibroblasts and infiltrating immune cells 7-9. Thus, our second objective will be to demonstrate the utility of dual bioluminescent techniques in monitoring the growth and localization of two unique cell populations harbored within a single animal during breast cancer growth and metastasis.

In vivo Dual Substrate Bioluminescent Imaging

Herein we describe the methods to construct, visualize, and quantify the bioluminescent reactions of both firefly and renilla luciferase enzymes expressed in metastatic breast cancer cells during their growth and metastasis in vivo.

Our understanding of how and when breast cancer cells transit from established primary tumors to metastatic sites has increased at an exceptional rate ...

Isolation of Soluble and Insoluble PrP Oligomers in the Normal Human Brain

The central event in the pathogenesis of prion diseases involves a conversion of the host-encoded cellular prion protein PrPC into its pathogenic isoform PrPSc 1. PrPC is detergent-soluble and sensitive to proteinase K (PK)-digestion, whereas PrPSc forms detergent-insoluble aggregates and is partially resistant to PK2-6. The conversion of PrPC to PrPSc is known to involve a conformational transition of &alpha;-helical to &beta;-sheet structures of the protein. However, the in vivo pathway is still poorly understood. A tentative endogenous PrPSc, intermediate PrP* or "silent prion", has yet to be identified in the uninfected brain7.
Using a combination of biophysical and biochemical approaches, we identified insoluble PrPC aggregates (designated iPrPC) from uninfected mammalian brains and cultured neuronal cells8, 9. Here, we describe detailed procedures of these methods, including ultracentrifugation in detergent buffer, sucrose step gradient sedimentation, size exclusion chromatography, iPrP enrichment by gene 5 protein (g5p) that specifically bind to structurally altered PrP forms10, and PK-treatment. The combination of these approaches isolates not only insoluble PrPSc and PrPC aggregates but also soluble PrPC oligomers from the normal human brain. Since the protocols described here have been used to isolate both PrPSc from infected brains and iPrPC from uninfected brains, they provide us with an opportunity to compare differences in physicochemical features, neurotoxicity, and infectivity between the two isoforms. Such a study will greatly improve our understanding of the infectious proteinaceous pathogens. The physiology and pathophysiology of iPrPC are unclear at present. Notably, in a newly-identified human prion disease termed variably protease-sensitive prionopathy, we found a new PrPSc that shares the immunoreactive behavior and fragmentation with iPrPC 11, 12. Moreover, we recently demonstrated that iPrPC is the main species that interacts with amyloid-&beta; protein in Alzheimer disease13. In the same study, these methods were used to isolate Abeta aggregates and oligomers in Alzheimer's disease13, suggesting their application to non-prion protein aggregates involved in other neurodegenerative disorders.

A new species of cellular prion protein (PrPC) has recently been identified in uninfected human brains using the methods described here. These methods can be used to isolate various PrP species, while some of them are also useful in isolating other misfolded protein aggregates from human brains.

The central event in the pathogenesis of prion diseases involves a conversion of the host-encoded cellular prion protein PrPC into its pathogenic isoform ...

Flexible Colonoscopy in Mice to Evaluate the Severity of Colitis and Colorectal Tumors Using a Validated Endoscopic Scoring System

The use of modern endoscopy for research purposes has greatly facilitated our understanding of gastrointestinal pathologies. In particular, experimental endoscopy has been highly useful for studies that require repeated assessments in a single laboratory animal, such as those evaluating mechanisms of chronic inflammatory bowel disease and the progression of colorectal cancer. However, the methods used across studies are highly variable. At least three endoscopic scoring systems have been published for murine colitis and published protocols for the assessment of colorectal tumors fail to address the presence of concomitant colonic inflammation. This study develops and validates a reproducible endoscopic scoring system that integrates evaluation of both inflammation and tumors simultaneously. This novel scoring system has three major components: 1) assessment of the extent and severity of colorectal inflammation (based on perianal findings, transparency of the wall, mucosal bleeding, and focal lesions), 2) quantitative recording of tumor lesions (grid map and bar graph), and 3) numerical sorting of clinical cases by their pathological and research relevance based on decimal units with assigned categories of observed lesions and endoscopic complications (decimal identifiers). The video and manuscript presented herein were prepared, following IACUC-approved protocols, to allow investigators to score their own experimental mice using a well-validated and highly reproducible endoscopic methodology, with the system option to differentiate distal from proximal endoscopic colitis (D-PECS).

Over the past few years, new generation endoscopes have emerged as important diagnostic research aids for evaluating murine colitis and colorectal tumors. We present herein a detailed protocol for endoscopic assessment of inflammation and colorectal tumors in mice, as well as a novel scoring system that uses decimal identifiers to document the endoscopic severity of colitis and colorectal tumors.

The use of modern endoscopy for research purposes has greatly facilitated our understanding of gastrointestinal pathologies. In particular, experimental ...

Intrarenal Injection of Escherichia coli in a Rat Model of Pyelonephritis

Pyelonephritis is a bacterial infection of the kidney and is most commonly caused by Escherichia coli. Recurrent infections can cause significant renal inflammation and fibrosis ultimately resulting in declining kidney function. Before improved clinical management and prevention of pyelonephritis can be instituted, a reliable animal model must be established in order to study the mechanisms of progression, recurrence, and therapeutic efficacy. The transurethral infection model closely mimics human pyelonephritis but exhibits considerable variation due to its reliance on urethral reflux to transport the bacteria to the kidney. Herein, a detailed surgical protocol for performing bacterial injections into the rat renal pelvis is provided and confirmed by non-invasive Magnetic Resonance Imaging (MRI). Using this protocol, animals receive direct exposure to a desired concentration of E. coli bacteria and can fully recover from the surgical procedure with adequate post-operative care. This facilitates subsequent longitudinal MRI assessments of the experimental animal models for comparison with saline (sham) controls. Using this direct delivery approach, the severity of infection is controllable and applicable for mechanistic studies of progression as well as development of novel treatment strategies.

Intrarenal Injection of Escherichia coli in a Rat Model of Pyelonephritis

This manuscript describes a rat surgical model of pyelonephritis using direct intra-renal infection by Escherichia coli into the renal pelvis. The experimental procedure can be utilized to study the pathogenesis of pyelonephritis as well as the associated inflammation and fibrosis.

Pyelonephritis is a bacterial infection of the kidney and is most commonly caused by Escherichia coli. Recurrent infections can cause significant renal ...

Novel Diagnostics in Revision Arthroplasty: Implant Sonication and Multiplex Polymerase Chain Reaction

In orthopedic patients, foreign body-associated infections, especially periprosthetic joint infections (PJIs), are a devastating complication of arthroplasty. Infection requires complex treatment, may result in long hospitalization and causes considerable costs. Multiple surgical revisions can be necessary in these patients, with a loss in function as well as in quality of life.
The routine preoperative diagnostics include blood examination for C-reactive protein (CRP) and other biomarkers, as well as joint aspirate analysis for cell count, differentiation, and culture. Intraoperative specimens for histology and microbiology are also standard procedure. The microbiological examination of removed implants with sonication, in combination with the implementation of molecular biology techniques in microbiology, represent two novel techniques currently employed to enhance the differential diagnostics of PJI.
We present here the step-wise procedure of analyzing joint aspirate and sonication fluid, using a cartridge-based multiplex polymerase chain reaction (PCR) system. Results were matched against conventional cultures and consensus criteria for PJI. Conventional microbiological cultures from tissue biopsies, joint aspirate and sonication fluid showed a sensitivity of 66.7%, 66.7%, and 88.9%, respectively, and a specificity of 82.3%, 54.6%, and 61.5%, respectively. The PCR diagnostic of the sonication fluid and the joint fluid showed a sensitivity of 50.0% and 55.6%, respectively, and both a specificity of 100.0%. Both PCR diagnostics combined had a sensitivity of 66.7% and a specificity of 100.0%. The multiplex PCR therefore presents a rapid diagnostic tool with moderate sensitivity but high specificity in diagnosing PJI.

Differential diagnostics in painful arthroplasty is crucial for treatment success. Joint aspiration is routinely performed preoperatively. Multiplex polymerase chain reaction of the joint aspirate and the sonication fluid, a feasible tool for quick pathogen detection from these samples is described.

In orthopedic patients, foreign body-associated infections, especially periprosthetic joint infections (PJIs), are a devastating complication of ...

Ultrasound-guided Intracardiac Injection of Human Mesenchymal Stem Cells to Increase Homing to the Intestine for Use in Murine Models of Experimental Inflammatory Bowel Diseases

Crohn&#39;s disease (CD) is a common chronic inflammatory disease of the small and large intestines. Murine and human mesenchymal stem cells (MSCs) have immunosuppressive potential and have been shown to suppress inflammation in mouse models of intestinal inflammation, even though the route of administration can limit their homing and effectiveness 1,3,4,5. Local application of MSCs to colonic injury models has shown greater efficacy at ameliorating inflammation in the colon. However, there is paucity of data on techniques to enhance the localization of human bone marrow-derived MSCs (hMSCs) to the small intestine, the site of inflammation in the SAMP-1/YitFc (SAMP) model of experimental Crohn&#39;s disease. This work describes a novel technique for the ultrasound-guided intracardiac injection of hMSCs in SAMP mice, a well-characterized spontaneous model of chronic intestinal inflammation. Sex- and age-matched, inflammation-free AKR/J (AKR) mice were used as controls. To analyze the biodistribution and the localization, hMSCs were transduced with a lentivirus containing a triple reporter. The triple reporter consisted of firefly luciferase (fl), for bioluminescent imaging; monomeric red fluorescent protein (mrfp), for cell sorting; and truncated herpes simplex virus thymidine kinase (ttk), for positron emission tomography (PET) imaging. The results of this study show that 24 h after the intracardiac administration, hMSCs localize in the small intestine of SAMP mice as opposed to inflammation-free AKR mice. This novel, ultrasound-guided injection of hMSCs in the left ventricle of SAMP mice ensures a high success rate of cell delivery, allowing for the rapid recovery of mice with minimal morbidity and mortality. This technique could be a useful method for the enhanced localization of MSCs in other models of small-intestinal inflammation, such as TNF&#916;RE6. Future studies will determine if the increased localization of hMSCs by intra-arterial delivery can lead to increased therapeutic efficacy.

Murine studies in models of colonic inflammation have demonstrated that a small percentage (1 - 5%) of mesenchymal stem cells (MSC) injected intravenously or intraperitoneally home to the inflamed colon1,2. This study shows that ultrasound-guided intracardiac injections of MSCs result in increased localization to the intestine.

Crohn&#39;s disease (CD) is a common chronic inflammatory disease of the small and large intestines. Murine and human mesenchymal stem cells (MSCs) have ...

Re-Arterialized Rat Partial Liver Transplantation with an in vivo Vessel-Oriented 70% Hepatectomy

Split liver transplantation and living liver donor liver transplantation were developed in the clinic to utilize liver organs in a more efficient manner. To better understand the mechanism behind these surgical procedures, a rat partial liver transplantation (PLTx) model was established for relevant surgical studies. Because of the complexity of the rat PLTx model, a protocol with detailed descriptions is required. An article published previously reported a protocol in which ex vivo hepatectomy was used to achieve 50% rat PLTx. In contrast to this protocol, we introduced a re-arterialized PLTx with an in vivo 70% hepatectomy. An updated vessel-oriented hepatectomy was incorporated into the rat PLTx to refine the microsurgical procedure. The portal veins and hepatic arteries of the left lateral lobe and the median lobe were individually dissected and ligated before removal of the liver parenchyma, thereby decreasing the probability of bleeding in the remnant liver stump. Furthermore, an end-to-side vessel anastomosis between the common hepatic artery and the enlarged proper hepatic artery was introduced to re-arterialize the hepatic artery. By using this end-to-side vessel anastomosis technique, the diameter of the anastomosis was enlarged, thereby decreasing the difficulty of hand suture and maintaining a high rate of anastomotic patency. Moreover, the cuff anastomosis of the infrahepatic vena cava was slightly modified. A section of circumferential liver parenchyma around the vena cava of a recipient was preserved during cuff anastomosis to maintain the three-dimensional shape of the vascular lumen. This section of liver parenchyma was removed after completing the anastomosis. With this modification, the step involving placement of stay sutures was omitted, thereby further shortening the cuff anastomosis time. By using this protocol of rat PLTx, a low liver enzyme level, an intact liver lobular architecture and a high survival rate were achieved after microsurgery.

Re-Arterialized Rat Partial Liver Transplantation with an in vivo Vessel-Oriented 70% Hepatectomy

Here, a protocol involving re-arterialized rat partial liver transplantation is presented. Specifically, 70% liver was resected in vivo by using an updated technique of vessel-oriented hepatectomy. The hepatic artery was reconstructed in an end-to-side manner. The cuff technique was modified to shorten the anastomosis time of the infrahepatic vena cava.

Split liver transplantation and living liver donor liver transplantation were developed in the clinic to utilize liver organs in a more efficient manner. ...

Individualized Stem-positioning in Calcar-guided Short-stem Total Hip Arthroplasty

Bone- and soft-tissue sparing short stems are increasingly used in total hip arthroplasty (THA). However, there are a large variety of models of short stems, differing in design and function. Calcar-guided short stems provide an anatomical curvature in the medial calcar region, thus, positioning is done individually alongside the calcar in the "round-the-corner" technique. Depending on the level of the neck's osteotomy, stems can be aligned individually in a large bandwidth of varus- and valgus anatomies. This differs from conventional total hip arthroplasty and potentially includes a severe learning curve. Given that a great variety of caput-collum-diaphyseal (CCD)-angles can be retained, the reconstruction of femoro-acetabular offsets can be achieved precisely. However, particularly extensive varus- and valgus positioning has raised concerns in regard to stability and bone remodeling. The purpose of the present manuscript is to showcase the implantation technique in calcar-guided short-stem THA and to summarize short-term clinical and radiological results.

This protocol describes the round-the-corner technique and the individualized stem-positioning of calcar-guided short stems alongside the medial calcar, depending on the level of the osteotomy. This differs from conventional total hip arthroplasty and includes a learning curve.

Bone- and soft-tissue sparing short stems are increasingly used in total hip arthroplasty (THA). However, there are a large variety of models of short ...

A Metadata Extraction Approach for Clinical Case Reports to Enable Advanced Understanding of Biomedical Concepts

Clinical case reports (CCRs) are a valuable means of sharing observations and insights in medicine. The form of these documents varies, and their content includes descriptions of numerous, novel disease presentations and treatments. Thus far, the text data within CCRs is largely unstructured, requiring significant human and computational effort to render these data useful for in-depth analysis. In this protocol, we describe methods for identifying metadata corresponding to specific biomedical concepts frequently observed within CCRs. We provide a metadata template as a guide for document annotation, recognizing that imposing structure on CCRs may be pursued by combinations of manual and automated effort. The approach presented here is appropriate for organization of concept-related text from a large literature corpus (e.g., thousands of CCRs) but may be easily adapted to facilitate more focused tasks or small sets of reports. The resulting structured text data includes sufficient semantic context to support a variety of subsequent text analysis workflows: meta-analyses to determine how to maximize CCR detail, epidemiological studies of rare diseases, and the development of models of medical language may all be made more realizable and manageable through the use of structured text data.

We present a protocol and associated metadata template for the extraction of text describing biomedical concepts in clinical case reports. The structured text values produced through this protocol can support deep analysis of thousands of clinical narratives.

Clinical case reports (CCRs) are a valuable means of sharing observations and insights in medicine. The form of these documents varies, and their content ...

The Use of Mixed Reality in Custom-Made Revision Hip Arthroplasty: A First Case Report

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Individualized Stem-positioning in Calcar-guided Short-stem Total Hip Arthroplasty

A Metadata Extraction Approach for Clinical Case Reports to Enable Advanced Understanding of Biomedical Concepts