Role of WNT Agonists, BMP and VEGF Antagonists in Rescuing Osteoarthritic Knee Cartilage in a Rat Model.

INTRODUCTION: The superficial zone of articular cartilage (AC) is vital for its function and biomechanics. The damaged AC gets vascularized and undergoes hypertrophy and ossification. Studies have highlighted these two as the major causative factors in osteoarthritis (OA). We aimed at preventing the OA progression in a rat knee instability model by inhibiting the vascular ingrowth and ossification using VEGF and BMP antagonist. A WNT agonist was also used to promote AC regeneration because of its protective effect on the superficial layer. METHODS: Rat knee OA was created by surgical excision of the medial meniscus and medial collateral ligament. Forty rats were divided into two groups of twenty each for surgical control and tests (surgery + intra-articular injection of drugs every two weeks). Ten animals from each group were sacrificed at four and eight weeks. Histology was mainly used to evaluate the outcome. RESULTS: A surgical OA model was successfully created with higher histological scores for operated knees, both in short- (P = 0.0001) and long-term (P = 0.001). Modified Mankin score was lesser in the test animals as compared to control (P = 0.17) in the short-term, but the trend was reversed in the long-term (P = 0.13). Subgroup analysis revealed that repeated injections in the anterolateral compartment contributed to higher scores in the lateral (P = 0.03) and anterior (P = 0.03) compartment of the knee in the long-term. CONCLUSION: The combinatorial approach was effective in controlling the OA in short-term. Further studies are needed to test the sustained drug delivery system to improve the outcome.

Long-Term Evaluation of Allogenic Chondrocyte-Loaded PVA-PCL IPN Scaffolds for Articular Cartilage Repair in Rabbits.

OBJECTIVE: This study tested the long-term efficacy of two synthetic scaffolds for osteochondral defects and compare the outcomes with that of an established technique that uses monolayer cultured chondrocytes in a rabbit model. METHODS: Articular cartilage defect was created in both knees of 18 rabbits and divided into three groups of six in each. The defects in first group receiving cells loaded on Scaffold A (polyvinyl alcohol-polycaprolactone semi-interpenetrating polymer network (Monophasic, PVA-PCL semi-IPN), the second on Scaffold B (biphasic, PVA-PCL incorporated with bioglass as the lower layer), and the third group received chondrocytes alone. One animal from each group was sacrificed at 2 months and the rest at 1 year. O'Driscoll's score measured the quality of cartilage repair. RESULTS: The histological outcome had good scores (22, 20, and 19) for all three groups at 2 months. At 1-year follow-up, the chondrocyte alone group had the best scores (mean 20.0 ± 1.4), while the group treated by PVA-PCL semi-IPN scaffolds fared better (mean 15 ± 4.2) than the group that received biphasic scaffolds (mean 11.8 ± 5.9). In all three groups, defects treated without cells scored less than the transplant. CONCLUSION: These results indicate that while these scaffolds with chondrocytes perform well initially, their late outcome is disappointing. We propose that for all scaffold-based tissue repairs, a long-term evaluation should be mandatory. The slow degrading scaffolds need further modifications to improve the milieu for long-term growth of chondrocytes and their hyaline phenotype for the better incorporation of tissue-engineered constructs.

Development of a Unique Mouse Intervertebral Disc Degeneration Model Using a Simple Novel Tool.

STUDY DESIGN: Animal case control study. PURPOSE: To create a simple, reproducible disc degeneration model for mouse coccygeal vertebrae. OVERVIEW OF LITERATURE: Back pain due to disc degeneration is probably the most common problem encountered in neurosurgical practice. An easily reproducible animal model for disc degeneration will help in understanding its pathophysiology, and serve as a platform for examining various therapeutic options. METHODS: A total of 18 mice were divided into injured (n=12) and non-injured (n=6) groups. The disc height index (DHI%) at coccygeal 4-5 level was measured by computed tomography (CT) scan for all mice. Coccygeal 4-5 discs of the injury group were injured using a 32G needle fixed to a novel tool and confirmed by CT. The non-injury group underwent no procedure. DHI% was measured by CT at 2-, 4-, and 6-week post-injury, and all mice tails were sectioned for histopathology grading of disc degeneration at the respective time intervals. RESULTS: The injured group showed significant variation in DHI% at 2, 4, and 6 weeks, whereas there was no change in the noninjured group. Histopathologic evaluation with Safranin O stain showed a worsening of the disc degeneration score at 2, 4, and 6 weeks in the injured group, but in the non-injured group there was no change. Percutaneous needle injury technique with our novel tool provided 100% accuracy and uniform degeneration. CONCLUSIONS: A simple, easily reproducible mouse model for disc degeneration was created using a simple, cost-effective, novel tool and technique, its advantage being high precision and user friendly.

Bone Marrow-Derived Mesenchymal Stem Cells Augment Regeneration of Intervertebral Disc in a Reproducible and Validated Mouse Intervertebral Disc Degeneration Model.

BACKGROUND: Back pain and radicular pain due to disc degeneration are probably the most common problems encountered in neurosurgical practice. The experience and results of stem cell therapy in animal disc degeneration model will help us while doing clinical trials. OBJECTIVE: To study the effect of bone marrow-derived mesenchymal stem cells in an established mouse disc degeneration model. METHODS: An easily reproducible mouse coccygeal (Co) 4-5 disc degenerated model by CT-guided percutaneous needle injury was established. The mesenchymal stem cells (MSCs) were cultured from mouse bone marrow and validated. By an established technique, 24 mice disc degenerative models were generated and divided equally into 3 groups (test, placebo, and control). The test group received MSCs with fibrin glue scaffold and placebo group received only scaffold after 6 weeks of degeneration. The control group did not receive any injection. The effects of MSCs were analyzed 8 weeks post injection. RESULTS: The test group showed a significant change in disc height index (%) in micro CT, whereas in the placebo and control groups, there was no change. The Safranin O staining showed an increase in glycosaminoglycan content and the polarized imaging of picrosirius red staining showed restoration of the collagen fibers in annulus fibrosus, which was statistically significant. CONCLUSION: Intradiscal MSC injection restored disc height and promoted regeneration in the discs at the end of 8 weeks. MSC's niche depends on the microenvironment of the host tissue. These findings will be helpful for clinical trials.

In vivo cartilage regeneration in a multi-layered articular cartilage architecture mimicking scaffold.

AIMS: Extracellular matrix (ECM) and its architecture have a vital role in articular cartilage (AC) structure and function. We hypothesized that a multi-layered chitosan-gelatin (CG) scaffold that resembles ECM, as well as native collagen architecture of AC, will achieve superior chondrogenesis and AC regeneration. We also compared its in vitro and in vivo outcomes with randomly aligned CG scaffold. METHODS: Rabbit bone marrow mesenchymal stem cells (MSCs) were differentiated into the chondrogenic lineage on scaffolds. Quality of in vitro regenerated cartilage was assessed by cell viability, growth, matrix synthesis, and differentiation. Bilateral osteochondral defects were created in 15 four-month-old male New Zealand white rabbits and segregated into three treatment groups with five in each. The groups were: 1) untreated and allogeneic chondrocytes; 2) multi-layered scaffold with and without cells; and 3) randomly aligned scaffold with and without cells. After four months of follow-up, the outcome was assessed using histology and immunostaining. RESULTS: In vitro testing showed that the secreted ECM oriented itself along the fibre in multi-layered scaffolds. Both types of CG scaffolds supported cell viability, growth, and matrix synthesis. In vitro chondrogenesis on scaffold showed an around 400-fold increase in collagen type 2 (COL2A1) expression in both CG scaffolds, but the total glycosaminoglycan (GAG)/DNA deposition was 1.39-fold higher in the multi-layered scaffold than the randomly aligned scaffold. In vivo cartilage formation occurred in both multi-layered and randomly aligned scaffolds treated with and without cells, and was shown to be of hyaline phenotype on immunostaining. The defects treated with multi-layered + cells, however, showed significantly thicker cartilage formation than the randomly aligned scaffold. CONCLUSION: We demonstrated that MSCs loaded CG scaffold with multi-layered zonal architecture promoted superior hyaline AC regeneration.Cite this article: Bone Joint Res 2020;9(9):601-612.

Accuracy of Various MRI Sequences in Determining the Tumour Margin in Musculoskeletal Tumours.

BACKGROUND: It is imperative that bone tumour margin and extent of tumour involvement are accurately assessed pre-operatively in order for the surgeon to attain a safe surgical margin. In this study, we comprehensively assessed each of the findings that influence surgical planning, on various MRI sequences and compared them with the gold standard - pathology. MATERIAL/METHODS: In this prospective study including 21 patients with extremity bone tumours, margins as seen on various MRI sequences (T1, T2, STIR, DWI, post-gadolinium T1 FS) were measured and biopsies were obtained from each of these sites during the surgical resection. The resected tumour specimen and individual biopsy samples were studied to assess the true tumour margin. Margins on each of the MRI sequences were then compared with the gold standard - pathology. In addition to the intramedullary tumour margin, we also assessed the extent of soft tissue component, neurovascular bundle involvement, epiphyseal and joint involvement, and the presence or absence of skip lesions. RESULTS: T1-weighted imaging was the best sequence to measure tumour margin without resulting in clinically significant underestimation or overestimation of the tumour extent (mean difference of 0.8 mm; 95% confidence interval between -0.9 mm to 2.5 mm; inter-class correlation coefficient of 0.998). STIR and T1 FS post-gadolinium imaging grossly overestimated tumour extent by an average of 16.7 mm and 16.8 mm, respectively (P values <0.05). Post-gadolinium imaging was better to assess joint involvement while T1 and STIR were the best to assess epiphyseal involvement. CONCLUSIONS: T1-weighted imaging was the best sequence to assess longitudinal intramedullary tumour extent. We suggest that osteotomy plane 1.5 cm beyond the T1 tumour margin is safe and also limits unwarranted surgical bone loss. However, this needs to be prospectively proven with a larger sample size.

Inflammatory carotid pseudotumor: case report and review of the literature.

Inflammatory carotid pseudotumor is a rare differential of a unilateral neck swelling in the carotid triangle. A 48-year-old man presented with a firm non-tender gradually progressive left neck swelling for five months. Computed tomography angiogram revealed a mass encasing the common carotid. Patient underwent excision; histopathology was reported as inflammatory pseudotumor. Patient had a recurrence after eight months. Steroids were prescribed with which the swelling resolved, patient remained recurrence free at two-year follow-up.

Large retroperitoneal schwannoma mimicking a cystic ovarian mass in a patient with Hansen's disease.

We present a rare case of retroperitoneal cystic schwannoma of the pelvis in a patient with Hansen's disease that mimicked an ovarian cyst. Due to economic constraints and because the lesion was assumed to be of ovarian origin, the patient did not undergo any cross-sectional imaging other than sonography. Sonographically guided fine needle aspiration of the cystic lesion was inconclusive. A cystic schwannoma was diagnosed at laparotomy.

Lipofibromatosis: report of a rare paediatric soft tissue tumour.

The clinical, radiological and pathological features of a case of lipofibromatosis, a rare paediatric soft tissue neoplasm, are described. The tumour involved the foot of a male infant and was present at birth. Magnetic resonance imaging showed a lipomatous mass, with splaying of muscles of the sole by lobules of fat. Histopathological examination revealed typical findings of an admixture of mature adipose tissue and fibroblastic elements. The radiological and pathological features helpful in differentiating this entity from other fibro-fatty paediatric soft tissue tumours is discussed, and the relevant literature is briefly reviewed.

Cervical embryonal rhabdomyosarcoma and ovarian Sertoli-Leydig cell tumour: a more than coincidental association of two rare neoplasms?

A case in which an embryonal rhabdomyosarcoma of the cervix and an ovarian Sertoli-Leydig cell tumour of intermediate differentiation occurred in a 13-year-old girl is described. Although initially considered as a chance association, a review of the literature showed the co-occurrence of these two uncommon neoplasms in three previous cases. The reason for this association, which is thought to be more than coincidental, is not known, although an underlying genetic abnormality is a possibility. The ovarian tumour in this case was characterised by the presence of foci of cells with extremely pleomorphic nuclei, which initially raised the possibility of metastatic rhabdomyosarcoma. These were interpreted as foci of bizarre nuclei within the Sertoli-Leydig cell tumour.

Heterotopic ossification in the orbit.

BACKGROUND: While calcification of orbital hemangiomas has been reported previously, no reports exist of heterotopic ossifications occurring within the orbit. CASE DESCRIPTION: A 30-year-old male presented with spontaneous onset of painless progressive proptosis of the left eye, with diplopia. The preoperative radiologic findings are presented. The lesion was excised completely. The pathologic features and probable causes are discussed. CONCLUSIONS: Heterotopic ossification of the orbit should be considered in the differential diagnosis of an orbital lesion showing radiologic features of calcification or ossification.

Bone marrow transplantation from HLA-identical siblings as first-line treatment in patients with myelodysplastic syndromes: early transplantation is associated with improved outcome. Chronic Leukemia Working Party of the European Group for Blood and Marrow Transplantation.

Allogeneic bone marrow transplantation (BMT) offers a potential cure for younger patients with myelodysplastic syndromes (MDS) or secondary acute myeloid leukemia (sAML). More than 600 patients from 50 European centers have now been reported to the European Group for Blood and Marrow Transplantation (EBMT). We retrospectively analyzed 131 patients reported to the Chronic Leukemia Working Party of the EBMT who underwent BMT from HLA-identical siblings without prior remission induction chemotherapy. At the time of BMT 46 patients had refractory anemia (RA) or RA with ringed sideroblasts, 67 patients had more advanced MDS subtypes and 18 patients had progressed to sAML. The 5-year disease-free (DFS) and overall survival (OS) for the entire group of patients was 34 and 41%, respectively. Fifty patients died from transplant-related complications, most commonly graft-versus-host disease and/or infections. Relapse occurred in 28 patients between 1 and 33 months after BMT, resulting in an actuarial probability of relapse of 39% at 5 years. DFS and OS were dependent on pretransplant bone marrow blast counts. Patients with RA/RARS, RAEB, RAEB/T and sAML had a 5-year DFS of 52, 34, 19 and 26%, respectively. The 5-year OS for the respective patient groups was 57, 42, 24 and 28%. In a multivariate analysis, younger age, shorter disease duration, and absence of excess of blasts were associated with improved outcome. From these data we conclude that patients with myelodysplasia who have appropriate marrow donors, especially those aged less than 40 years and those with low medullary blast cell count should be treated with BMT as the primary treatment early in the course of their disease. Transplantation early after establishing the diagnosis of MDS may improve prognosis due to a lower treatment-related mortality and a lower relapse risk.