Setting Up 3D Printing Services for Orthopaedic Applications: A Step-by-Step Guide and an Overview of 3DBioSphere.

INTRODUCTION: 3D printing has widespread applications in orthopaedics including creating biomodels, patient-specific instruments, implants, and developing bioprints. 3DGraphy or printing 3D models enable the surgeon to understand, plan, and simulate different procedures on it. Despite widespread applications in non-healthcare specialties, it has failed to gain traction in healthcare settings. This is perhaps due to perceived capital expenditure cost and the lack of knowledge and skill required to execute the process. PURPOSE: This article is written with an aim to provide step-by-step instructions for setting up a cost-efficient 3D printing laboratory in an institution or standalone radiology centre. The article with the help of video modules will explain the key process of segmentation, especially the technique of edge detection and thresholding which are the heart of 3D printing. CONCLUSION: This is likely to enable the practising orthopaedician and radiologist to set up a 3D printing unit in their departments or even standalone radiology centres at minimal startup costs. This will enable maximal utilisation of this technology that is likely to bring about a paradigm shift in planning, simulation, and execution of complex surgeries.

Regeneration of hyaline cartilage in osteochondral lesion model using L-lysine magnetic nanoparticles labeled mesenchymal stem cells and their in vivo imaging.

Treatment of osteochondral defects continues to pose a major challenge for patients and orthopedic surgeons due to the limited healing potential of articular cartilage. Mesenchymal stem cells (MSCs) possess therapeutic potential for the treatment of osteochondral pain and pathology. However, it is necessary to use proper labeling and imaging agent of stem cells that can decipher its role posttransplantation. A major limitation of routinely used contrast agents is signal dilution over a period of time which limits its use for further studies. At the same time, regeneration of fibrocartilage over native hyaline cartilage also limits the use of conventional therapies. The present study evaluates the efficacy of bone marrow-derived mesenchymal stem cells (BMSCs) for the treatment of osteochondral defect in rats with the regeneration of hyaline cartilage in situ and in vivo monitoring of the stem cells using L-lysine functionalized magnetic iron oxide nanoparticles (lys-IONPs). L-lysine stabilizes the iron oxide nanoparticles, enhances the biocompatibility, and provides functionalities for efficient stem cell labeling. in vitro toxic effects of lys-IONPs on mitochondrial impairment, morphological alterations, and actin cytoskeleton reveal minimum damage to BM-MSCs. Histological data (H and E, Masson's trichrome and immunohistochemistry) describe the early initiation of healing and regeneration of hyaline-like cartilage over fibrocartilage in stem cell treated groups. MR scans demonstrate generation of hypointense signals in lys-IONPs-BMSCs with improved signal intensity and minimum loss over 28 days revealing its use as a long-term stem cell labeling and imaging agent.

Cardiac magnetic resonance imaging, myocardial scar and coronary flow pattern in anomalous origin of left coronary artery from the pulmonary artery.

BACKGROUND: Anomalous origin of left coronary artery from pulmonary artery (ALCAPA) is a very rare congenital heart defect characterized by myocardial ischemia and ultimately scaring. The scar burden will determine eventual recovery of left ventricular function after corrective surgery. MATERIAL METHOD: All patients with proven diagnosis of ALCAPA and who underwent treatment at present centre were included. Detail echocardiography and cardiac magnetic resonance imaging (CMR) (delayed Gadolinium enhancement) was performed before and after surgery. RESULTS: There were 4 patients (3 females, age group 3 months to 3 yr, follow up 6 months to 20 months.) There was no peri operative mortality. All patients had significant improvement in symptom class and LVEF (increase of more than 10%) when evaluated at last follow up. Three patients had pre operative CMR and 3 post operative CMR. All patients had improvement in post operative LVEF, but >50% was observed only in one patient who had less than half thickness delayed gadolinium enhancement. The right coronary flow pattern were unique to disease. The left coronary flow pattern were had significant variation and could predict extent of scared myocardium. CONCLUSION: Ischemia in ALCAPA can lead to myocardial scarring even in early infancy. The recovery in left ventricular function is a closely related to scar burden. Coronary flow patterns are unique and give useful insight into disease process and natural history.

Imaging of articular cartilage.

We tried to review the role of magnetic resonance imaging (MRI) in understanding microscopic and morphologic structure of the articular cartilage. The optimal protocols and available spin-echo sequences in present day practice are reviewed in context of common pathologies of articular cartilage. The future trends of articular cartilage imaging have been discussed with their appropriateness. In diarthrodial joints of the body, articular cartilage is functionally very important. It is frequently exposed to trauma, degeneration, and repetitive wear and tear. MRI has played a vital role in evaluation of articular cartilage. With the availability of advanced repair surgeries for cartilage lesions, there has been an increased demand for improved cartilage imaging techniques. Recent advances in imaging strategies for native and postoperative articular cartilage open up an entirely new approach in management of cartilage-related pathologies.

Radiological features of hepatocellular carcinoma.

Present article is a review of radiological features of hepatocellular carcinoma on various imaging modalities. With the advancement in imaging techniques, biopsy is rarely needed for diagnosis of hepatocellular carcinoma (HCC), unlike other malignancies. Imaging is useful not only for diagnosis but also for surveillance, therapy and assessing response to treatment. The classical and the atypical radiological features of HCC have been described.

Paediatric intra-axial posterior fossa tumours: pictorial review.

Paediatric brain tumours commonly arise in the posterior cranial fossa. Early diagnosis is often challenging due to initial non-specific clinical symptoms, especially in very young children. The typical MR features of tumours in this region including medulloblastoma, ependymoma, juvenile pilocytic subtype of cerebellar astrocytoma, brain stem glioma and atypical teratoid-rhabdoid tumour are illustrated. Diffusion-weighted imaging and apparent diffusion coefficient values combined with signal characteristics on conventional MR sequences can usually differentiate low-grade from high-grade tumours. Prompt diagnosis is crucial as total surgical resection, which is only possible in localised disease, improves prognosis. A practical MR flow chart is introduced for differentiating different types of posterior cranial fossa tumours, which might be useful in clinical practice.

Primary spinal cord desmoplastic astrocytoma in an adolescent: a rare tumour at rare site and rare age.

We report a case of a non-infantile primary intramedullary spinal cord desmoplastic astrocytoma in an 18-year-old girl who presented with spastic paraparesis. The patient had been unable to run for 1 year. Magnetic resonance imaging of her spine showed an intramedullary solid and cystic heterogeneously enhancing lesion located at T7-T8 level. Partial excision was performed. Histology revealed a desmoplastic astrocytoma. To the best of our knowledge, there is no report on primary desmoplastic astrocytoma of the spinal cord in literature. Nor has such a symptomatic tumour manifesting at the age of 18 years been documented.

Radiographic study of the hip joint to determine anthropometric parameters for Indian population.

Hip replacement surgeries are on the rise in India. However, for these surgeries, most of the implants used are imported and manufactured entirely to suit the geometrical considerations of the western population. Studies in the past have shown that there are anatomical variations in the hip joint for different ethnic backgrounds and geographical locations. There is paucity of anthropometric hip joint data related to Indian population and anthropometric variations in skeletal geometry between Asian and Western counterparts have not yet been thoroughly reviewed and considered for implant manufacturing. The purpose of this anthropometric study is to determine any anatomical variations in the normal hip joint among the Indian population and to statistically compare the mean values with the existing data on western population. 422 Hip radiographs of 211 individuals (141 males and 70 females) with normal and healthy hip joints were evaluated to obtain the horizontal offset, vertical offset and neck shaft angle. For males, mean neck shaft angle was 127.68° (SD = 3.94), horizontal offset was 34.60mm (SD=6.55) and vertical offset was 39.17 mm (SD = 5.86). For females, mean neck shaft angle was 125.92° (SD = 4.75), horizontal offset was 32.96 mm (SD = 7.04) and vertical offset was 36.38 mm (SD = 6.28). When these parameters were compared to the data available from western world, there were significant anatomical variations and it was evident that there is a need to evaluate existing implants in relation to this data and possibly design the implants suited and relevant to Indian population.

Intravascular papillary endothelial hyperplasia: report of two cases.

Intravascular papillary endothelial hyperplasia is a rare benign vascular proliferative process as a result of papillary proliferation of the endothelial cells within the vascular lumen. We report two cases of intravascular papillary endothelial hyperplasia affecting the extremities. The characteristic sonological and MR imaging features are discussed, with updated review of literature. Imaging features are helpful in achieving a definitive diagnosis of the intravascular papillary endothelial hyperplasia.

Use of rapid prototyping and three-dimensional reconstruction modeling in the management of complex fractures.

BACKGROUND: The production of a copy of the fracture or a deformity in a bone with a complex geometry can be one of the important applications of the integration between two modern computer-based technologies, reverse engineering (RE) and rapid prototyping (RP). METHODS: This article reviews recent development in this field and present a case series about the use of medical CT/MRI scanning, three-dimensional reconstruction, anatomical modeling, computer-aided design, RP and computer-aided implantation in treating a complex fracture of acetabulums, calcaneum, and medial condyle of femur (Hoffa's fracture). CONCLUSION: The use of RP technology helped us to understand the fracture configuration and to achieve near anatomical reduction. With this we believe, this technology will reduce the surgical time as was observed in our cases. This consequently, will lower the requirement of an anesthetic dosage and decrease the intraoperative blood loss.In summary, the merging of computational analysis, modeling, designing, and fabrication will serve as important means to treat conditions and fractures around joints, spine, acetabulum, and craniofacial region. LEVEL OF EVIDENCE: Level 4, case series.

Pulmonary metastases in children with osteosarcoma: characteristics and impact on patient survival.

BACKGROUND: Approximately 15-20% of patients with osteosarcoma present with detectable metastatic disease and the majority of whom (85%) have pulmonary lesions as the sole site of metastasis. Previous studies have shown that the overall survival rate among patients with localized osteosarcoma without metastatic disease is approximately 60-70% whereas survival rate reduces to 10-30% in patients with metastatic disease. OBJECTIVE: To determine the incidence and characteristic features of pulmonary metastases in a group of osteosarcoma patients and correlate the findings with the prognostic outcome/survival. MATERIALS AND METHODS: Seventy-seven cases of histologically confirmed osteosarcoma were reviewed (47 male, 30 female, mean age 10.9). The site and size of the primary tumour and degrees of chemonecrosis were recorded. Lung metastases were analyzed according to their size, number, distribution and interval from diagnosis. The Kaplan-Meier method was used to analyze the survival probability curve. Significant differences (P < 0.05) were evaluated with the log-rank test for univariate analyses. RESULTS: Seventeen patients had synchronous and 11 had metachronous lung metastases. Sixteen (57%) underwent pulmonary metastasectomy. Nine of sixteen (56%) patients with metastasectomy and 10/12 (83%) patients without metastasectomy died. Poor chemonecrosis was associated with a worse outcome. Number, distribution and timing of lung metastases, but not the size of lung metastases, were of prognostic value for survival. CONCLUSION: Radiological detection of lung metastases is clinically important as it indicates a worse prognosis.

Intra-abdominal testicular seminoma in a woman with testicular feminization syndrome.

We report a case of intra-abdominal testicular tumor in a 36-year-old married lady presenting with chief complaints of primary amenorrhea. The patient was later diagnosed with testicular feminization syndrome, a form of male pseudohermaphroditism. This testicular tumor was histologically proven as seminoma. Due to rarity, imaging findings in patients with testicular feminization syndrome and intraabdominal testicular tumor have been poorly documented. So far, only one case report had described the combined role of CT and MR imaging in intraabdominal testicular sex-cord stromal tumor. To our knowledge, this case is first to document USG and MR imaging in addition to MR spectroscopy features in intraabdominal testicular seminoma.

Imaging of the anterior cruciate ligament.

The anterior cruciate ligament (ACL) is an important structure in maintaining the normal biomechanics of the knee and is the most commonly injured knee ligament. However, the oblique course of the ACL within the intercondylar fossa limits the visualization and assessment of the pathology of the ligament. This pictorial essay provides a comprehensive and illustrative review of the anatomy and biomechanics as well as updated information on different modalities of radiological investigation of ACL, particularly magnetic resonance imaging.

Testicular hamartomas and epididymal tumor in a cowden disease: a case report.

Testicular hamartomas (TH) is a benign condition. An association of TH with Cowden disease (CD) is known. Ultrasound features of hamartomas are often diagnostic. We present a case of Cowden disease with TH and an epididymal tumor. Imaging features of TH and its differentials has been discussed. Although, association of Cowden disease with many malignancies have been documented, epididymal tumor has not been described. To our knowledge, this paper is the first to describe epididymal tumor in association with Cowden disease.

Migrating biliary stent with final destination at the ileocecal junction causing intestinal obstruction and obstructive biliopathy.

Endoscopic plastic biliary stent insertion is a minimally invasive, well-established procedure for the management of benign biliary pathology. We report a case of a migrating stent for over two days, which finally got impacted at the ileocecal junction, leading to intestinal obstruction and obstructive biliopathy. Radiological findings depicted the exact site of the dislodged biliary stent and its related complications, both of which were successfully treated in a nonoperative stepwise manner.