A pathological joint-liver axis mediated by matrikine-activated CD4+ T cells

The knee joint has long been considered a closed system. The pathological effects of joint diseases on distant organs have not been investigated. Herein, our clinical data showed that post-traumatic joint damage, combined with joint bleeding (hemarthrosis), exhibits a worse liver function compared with healthy control. With mouse model, hemarthrosis induces both cartilage degeneration and remote liver damage. Next, we found that hemarthrosis induces the upregulation in ratio and differentiation towards Th17 cells of CD4+ T cells in peripheral blood and spleen. Deletion of CD4+ T cells reverses hemarthrosis-induced liver damage. Degeneration of cartilage matrix induced by hemarthrosis upregulates serological type II collagen (COL II), which activates CD4+ T cells. Systemic application of a COL II antibody blocks the activation. Furthermore, bulk RNAseq and single-cell qPCR analysis revealed that the cartilage Akt pathway is inhibited by blood treatment. Intra-articular application of Akt activator blocks the cartilage degeneration and thus protects against the liver impairment in mouse and pig models. Taken together, our study revealed a pathological joint-liver axis mediated by matrikine-activated CD4+ T cells, which refreshes the organ-crosstalk axis and provides a new treatment target for hemarthrosis-related disease. Intra-articular bleeding induces cartilage degradation through down-reulation of cartilage Akt pathway. During this process, the soluble COL II released from the damaged cartilage can activate peripheral CD4+ T cells, differention into Th17 cells and secretion of IL-17, which consequently induces liver impairment. Intra-articular application of sc79 (inhibitor of Akt pathway) can prevent the cartilage damage as well as its peripheral influences.

[Study on the Therapeutic Effect of Lenalidomide on Hemophilic Arthropathy]

OBJECTIVE

To explore the effect of lenalidomide on human fibroblast-like synovial cells (HFLS) and the therapeutic efficacy on hemophilic arthropathy in hemophilia A mice model.

METHODS

In vitro, to remodel the inflammatory environment of synovial tissue after hemorrhage, ferric citrate and recombinant TNF-α were added into the cell culture medium of HFLS. Cell Counting Kit-8 (CCK-8), Enzyme-linked immunosorbent assay (ELISA), Quantitative Real-time PCR (RT-qPCR) and flow cytometry were employed for detection of the effects of lenalidomide on the proliferation ability, pro-inflammatory cytokines release and apoptosis of HFLS cells. In vivo, hemophilia arthropathy was remodeled in hemophilia A mice by induction of hemarthrosis. A series of doses of lenalidomide (0.1, 0.3 and 1.0 g/kg) was administrated intra-articularly. Tissues of knee joints were collected on the 14th day after administration, and the protective effect of lenalidomide on arthritis in hemophilia A mice were evaluated by RT-qPCR and histological grading.

RESULTS

In vitro, compared with the untreated control group, lenalidomide could significantly inhibit the proliferation of HFLS cells (P<0.05), and the effect was the most significant when the concentration was 0.01 μmol/L (P<0.001). Compared with the control group, lenalidomide could significantly inhibit the expression levels of TNF-α, IL-1β, IL-6 and IFN-γ in HFLS cells (P<0.05). The flow cytometry results showed that lenalidomide could enhance the apoptotis of HFLS cells (P<0.05). The results of RT-qPCR showed that lenalidomide could significantly reduce the mRNA expression levels of TNF-α, IL-1β, IL-6,MCP-1 and VEGF in the joint tissues (P<0.05). Histological results showed that compared with the injured group, lenalidomide could significantly reduce the pathological sequela after hemarthrosis induction, e.g. synovial thickening and neo-angiogenesis in the synovium. The protection displayed a dose-response pattern roughly.

CONCLUSION

In vitro, lenalidomide can inhibit the proliferation of HFLS cells, promote their apoptosis, and inhibit the expression of pro-inflammatory cytokines. In vivo, lenalidomide can significantly decrease the expression of pro-inflammatory cytokines in the joints of mice, and prevent the development of inflammation and neo-angiogenesis. The results provide a theoretical and experimental basis for the clinical application of lenalidomide in the treatment of hemophilic arthropathy.

Selective inhibition of activated protein C anticoagulant activity protects against hemophilic arthropathy in mice

Recurrent spontaneous or trauma-related bleeding into joints in hemophilia leads to hemophilic arthropathy (HA), a debilitating joint disease. Treatment of HA consists of preventing joint bleeding by clotting factor replacement, and in extreme cases, orthopedic surgery. We recently showed that administration of endothelial cell protein C receptor (EPCR) blocking monoclonal antibodies (mAb) markedly reduced the severity of HA in factor VIII (FVIII)-/- mice. EPCR blocking inhibits activated protein C (APC) generation and EPCR-dependent APC signaling. The present study was aimed to define the role of inhibition of APC anticoagulant activity, APC signaling, or both in suppressing HA. FVIII-/- mice were treated with a single dose of isotype control mAb, MPC1609 mAb, that inhibits anticoagulant, and signaling properties of APC, or MAPC1591 mAb that only blocks the anticoagulant activity of APC. Joint bleeding was induced by needle puncture injury. HA was evaluated by monitoring joint bleeding, change in joint diameter, and histopathological analysis of joint tissue sections for synovial hypertrophy, macrophage infiltration, neoangiogenesis, cartilage degeneration, and chondrocyte apoptosis. No significant differences were observed between MPC1609 and MAPC1591 in inhibiting APC anticoagulant activity in vitro and equally effective in correcting acute bleeding induced by the saphenous vein incision in FVIII-/- mice. Administration of MAPC1591, and not MPC1609, markedly reduced the severity of HA. MAPC1591 inhibited joint bleed-induced inflammatory cytokine interleukin-6 expression and vascular leakage in joints, whereas MPC1609 had no significant effect. Our data show that an mAb that selectively inhibits APC's anticoagulant activity without compromising its cytoprotective signaling offers a therapeutic potential alternative to treat HA.

The Progression of Hemophilic Arthropathy: The Role of Biomarkers

BACKGROUND

Hemophilia A and B are X-linked congenital bleeding disorders characterized by recurrent hemarthroses leading to specific changes in the synovium and cartilage, which finally result in the destruction of the joint: this process is called hemophilic arthropathy (HA). This review highlights the most prominent molecular biomarkers found in the literature to discuss their potential use in the clinical practice to monitor bleeding, to assess the progression of the HA and the effectiveness of treatments.

METHODS

A review of the literature was performed on PubMed and Embase, from 3 to 7 August 2020. Study selection and data extraction were achieved independently by two authors and the following inclusion criteria were determined a priori: English language, available full text and articles published in peer-reviewed journal. In addition, further articles were identified by checking the bibliography of relevant articles and searching for the studies cited in all the articles examined.

RESULTS

Eligible studies obtained at the end of the search and screen process were seventy-three (73).

CONCLUSIONS

Despite the surge of interest in the clinical use of biomarkers, current literature underlines the lack of their standardization and their potential use in the clinical practice preserving the role of physical examination and imaging in early diagnosis.

TAFI deficiency causes maladaptive vascular remodeling after hemophilic joint bleeding

Excessive vascular remodeling is characteristic of hemophilic arthropathy (HA) and may contribute to joint bleeding and the progression of HA. Mechanisms for pathological vascular remodeling after hemophilic joint bleeding are unknown. In hemophilia, activation of thrombin-activatable fibrinolysis inhibitor (TAFI) is impaired, which contributes to joint bleeding and may also underlie the aberrant vascular remodeling. Here, hemophilia A (factor VIII-deficient; FVIII-deficient) mice or TAFI-deficient mice with transient (antibody-induced) hemophilia A were used to determine the role of FVIII and TAFI in vascular remodeling after joint bleeding. Excessive vascular remodeling and vessel enlargement persisted in FVIII-deficient and TAFI-deficient mice, but not in transient hemophilia WT mice, after similar joint bleeding. TAFI-overexpression in FVIII-deficient mice prevented abnormal vessel enlargement and vascular leakage. Age-related vascular changes were observed with FVIII or TAFI deficiency and correlated positively with bleeding severity after injury, supporting increased vascularity as a major contributor to joint bleeding. Antibody-mediated inhibition of uPA also prevented abnormal vascular remodeling, suggesting that TAFI's protective effects include inhibition of uPA-mediated plasminogen activation. In conclusion, the functional TAFI deficiency in hemophilia drives maladaptive vascular remodeling in the joints after bleeding. These mechanistic insights allow targeted development of potentially new strategies to normalize vascularity and control rebleeding in HA.

Blood-induced bone loss in murine hemophilic arthropathy is prevented by blocking the iRhom2/ADAM17/TNF-α pathway

Hemophilic arthropathy (HA) is a debilitating degenerative joint disease that is a major manifestation of the bleeding disorder hemophilia A. HA typically begins with hemophilic synovitis that resembles inflammatory arthritides, such as rheumatoid arthritis, and frequently results in bone loss in patients. A major cause of rheumatoid arthritis is inappropriate release of the proinflammatory cytokine tumor necrosis factor-α (TNF-α) by the TNF-α convertase (TACE; also referred to as ADAM17) and its regulator, iRhom2. Therefore, we hypothesized that iRhom2/ADAM17-dependent shedding of TNF-α also has a pivotal role in mediating HA. Here, we show that addition of blood or its components to macrophages activates iRhom2/ADAM17-dependent TNF-α shedding, providing the premise to study the activation of this pathway by blood in the joint in vivo. For this, we turned to hemophilic FVIII-deficient mice (F8-/- mice), which develop a hemarthrosis following needle puncture injury with synovial inflammation and significant osteopenia adjacent to the affected joint. We found that needle puncture-induced bleeding leads to increased TNF-α levels in the affected joint of F8-/- mice. Moreover, inactivation of TNF-α or iRhom2 in F8-/- mice reduced the osteopenia and synovial inflammation that develops in this mouse model for HA. Taken together, our results suggest that blood entering the joint activates the iRhom2/ADAM17/TNF-α pathway, thereby contributing to osteopenia and synovitis in mice. Therefore, this proinflammatory signaling pathway could emerge as an attractive new target to prevent osteoporosis and joint damage in HA patients.

A fusion protein of interleukin-4 and interleukin-10 protects against blood-induced cartilage damage in vitro and in vivo

Essentials Targeted treatment for hemophilic arthropathy, still causing significant morbidity, is lacking. This study evaluates the efficacy of a fusion of protein of interleukin(IL)-4 and IL-10. In vitro the fusion protein prevents blood-induced cartilage damage in a dose-dependent manner. In hemophilic mice, the IL4-10 fusion protein ameliorates cartilage damage upon joint bleeding.

SUMMARY

Background Joint damage still causes significant morbidity in hemophilia. It results from synovial inflammation and direct cartilage-degenerating properties of blood components. Interleukin (IL)-4 and IL-10 have been shown to protect cartilage from blood-induced damage. Recently an IL4-10 fusion protein has been developed to combine the function of IL-4 and IL-10 and increase their bioavailability. Objectives In this study we evaluate whether this IL4-10 fusion protein protects against blood-induced joint damage. Methods In vitro, human cartilage explants were exposed to whole blood and simultaneously to a broad concentration range of the IL4-10 fusion protein. Effects on cartilage matrix turnover were compared with the individual cytokines. Moreover, the influence of the fusion protein and its individual components on IL-1β and IL-6 production was investigated. In hemophilia A mice, the effect of intra-articular treatment on synovitis and cartilage damage resulting from joint bleeding was evaluated by histochemistry. Results In vitro, the fusion protein prevented blood-induced cartilage damage in a dose-dependent manner, with equal effectiveness to the combination of the separate cytokines. In whole blood cultures 10 ng mL-1 fusion protein completely blocked the production of IL-1β and IL-6 by monocytes/macrophages. In hemophilic mice, intra-articular injection of IL-4 and IL-10 did not influence synovitis or cartilage degeneration. In contrast, equimolar amounts of the fusion protein attenuated cartilage damage upon repeated joint bleeding, although synovial inflammation was hardly affected. Conclusions Overall, this study shows that the IL4-10 fusion protein prevents blood-induced cartilage damage in vitro and ameliorates cartilage degeneration upon joint bleeding in hemophilic mice.

Management of Hemophilic Arthropathy of the Ankle

BACKGROUND

Hemophilic arthropathy (HA) of the ankle is prevalent in people with hemophilia (PWH). It is frequently severe and incapacitating, due to recurrent bleeding into the ankle articulation during infancy. Around 50% of hemophilic patients suffer from ankle pain and radiological signs of HA.

OBJECTIVE

To review current treatment of HA of the ankle in PWH.

METHOD

A literature review of hemophilic ankle arthropathy in PWH was performed utilizing MEDLINE (PubMed) and the Cochrane Library.

RESULTS

Primary hematologic prophylaxis could keep away from the development of ankle HA if the level of the patient's deficient factor is prevented from dropping below 1% of normal. Recurrent articular bleeding can be prevented by the intravenous infusion of clotting factor concentrates (prophylaxis). Major articular bleeds and chronic hemophilic synovitis should be managed fiercely to prevent ankle HA. In the circumstance of advancing articular involvement, some noninvasive and invasive procedures can procure symptomatic mitigation and ameliorate the patient's function and quality of life.

CONCLUSION

The ideal treatment for the hemophilic ankle when hematologic prophylaxis fails includes physical medicine and rehabilitation, orthoses, radiosynovectomy, arthroscopic ankle debridement (in the initial stages of cartilage degeneration), and ankle distraction, ankle fusion or total ankle replacement (in advanced stages of cartilage degeneration).

The F8(-/-) rat as a model of hemophilic arthropathy

Essentials Validating the F8 rat as a new intermediate-size animal model of hemophilic arthropathy. Factor VIII (FVIII) treated F8(-/-) rats suffered induced hemarthrosis analyzed by histopathology. F8 (-/-) animals develop hemophilic arthropathy upon hemarthrosis, preventable by FVIII treatment. The F8 (-/-) rat presents as a new pharmacologic model of hemophilic arthropathy.

SUMMARY

Background Translational animal models of hemophilia are valuable for determining the pathobiology of the disease and its co-morbidities (e.g. hemophilic arthropathy, HA). The biologic mechanisms behind the development of HA, a painful and debilitating condition, are not completely understood. We recently characterized a F8(-/-) rat, which could be a new preclinical model of HA. Objectives To establish the F8(-/-) rat as a model of HA by determining if the F8(-/-) rat develops HA resembling human HA after an induced joint bleed and whether a second joint bleed causes further disease progression. Methods Wild-type and F8(-/-) rats were treated with vehicle or recombinant human factor VIII (rhFVIII) prior to a needle-induced joint bleed. Joint swelling was measured prior to injury, the following 7 days and upon euthanasia. Histologic sections of the joint were stained, and athropathic changes identified and scored with regard to synovitis, bone remodelling, cartilage degradation and hemosiderin deposition. Results Vehicle-treated F8(-/-) rats experienced marked joint swelling and developed chronic degenerative joint changes (i.e. fibrosis of the subsynovial membrane, chondrocyte loss and excessive bone remodeling). Treatment with rhFVIII reduced or prevented swelling and degenerative joint changes, returning the F8(-/-) animals to a wild-type phenotype. Conclusion The hemophilic phenotype of the F8(-/-) rat resulted in a persistent hemarthrosis following an induced joint bleed. This caused development of HA resembling human HA, which was prevented by rhFVIII treatment, confirming the potential of the F8(-/-) rat as a model of HA.

Nuclear factor (NF)-κB and its associated pathways are major molecular regulators of blood-induced joint damage in a murine model of hemophilia

BACKGROUND

The present study was designed to investigate the molecular signaling events from onset of bleeding through the development of arthropathy in a murine model of hemophilia A.

METHODS AND RESULTS

A sharp-injury model of hemarthrosis was used. A global gene expression array on joint-specific RNA isolated 3 h post-injury revealed nuclear factor-kappa B (NF-κB) as the major transcription factor triggering inflammation. As a number of genes encoding the cytokines, growth factors and hypoxia regulating factors are known to be activated by NF-κB and many of these are part of the pathogenesis of various joint diseases, we reasoned that NF-κB-associated pathways may play a crucial role in blood-induced joint damage. To further understand its role, we screened NF-κB-associated pathways between 1 h to 90 days after injury. After a single articular bleed, distinct members of the NF-κB family (NF-κB1/NF-κB2/RelA/RelB) and their responsive pro-inflammatory cytokines (IL-1β/IL-6/IFNγ/TNFα) were significantly up-regulated (> 2 fold, P < 0.05) in injured vs. control joints at the various time-points analyzed (1 h/3 h/7 h/24 h). After multiple bleeds (days 30/60/75/90), there was increased expression of NF-κB-associated factors that contribute to hypoxia (HIF-1α, 3.3-6.5 fold), angiogenesis (VEGF-α, 2.5-4.4 fold) and chondrocyte damage (matrix metalloproteinase-13, 2.8-3.8 fold) in the injured joints. Micro RNAs (miR) that are known to regulate NF-κB activation (miRs-9 and 155), inflammation (miRs-16, 155 and 182) and apoptosis (miRs-19a, 155 and 186) were also differentially expressed (-4 to +13-fold) after joint bleeding, indicating that the small RNAs could modulate the arthropathy phenotype.

CONCLUSIONS

These data suggest that NF-κB-associated signaling pathways are involved in the development of hemophilic arthropathy.

IL-4 alone and in combination with IL-10 protects against blood-induced cartilage damage

OBJECTIVE

It has been reported that interleukin (IL)-10 limits blood-induced cartilage damage. Our aim was to study the effect of IL-4 alone and in combination with IL-10 on blood-induced cartilage damage.

DESIGN

Healthy human full thickness cartilage explants were cultured for 4 days in the presence of 50% v/v blood. IL-4, IL-10, or a combination of both cytokines was added during blood exposure. Cartilage matrix turnover was determined after a recovery period; additionally cytokine production, chondrocyte apoptosis, and expression of the IL-4 and IL-10 receptors were analyzed directly after exposure.

RESULTS

Blood-induced damage to the cartilage matrix was limited by IL-4 in a dose-dependent way (P<0.05). Also IL-10 limited this damage, although to a lesser extent (P<0.03). The effect of IL-4 plus IL-10 was more pronounced and protective than IL-10 alone (P<0.05). Production of IL-1β and tumor necrosis factor (TNF)-α was limited by both IL-4 and IL-10 (P<0.05), but more strongly by IL-4. Blood-induced apoptosis of chondrocytes was limited by IL-4 and the combination, and not by IL-10 alone. No direct beneficial effect of IL-4 or IL-10 on cartilage was found, however, the chondrocyte receptor expression of both cytokine receptors was upregulated by exposure to blood.

CONCLUSIONS

This study demonstrates that IL-4 alone and in combination with IL-10 prevents blood-induced cartilage damage. Expectedly, anti-inflammatory effects on monocytes in the blood fraction and protective effects on chondrocytes are both involved. IL-4 in combination with IL-10 might be used to prevent blood-induced joint damage as a result of trauma or surgery.

[Microcirculatory investigations in hemophilia patients]

AIM

to evaluate microcirculation (MC) and its influencing factors in hemophilia patients.

SUBJECTS AND METHODS

In 44 hemophilia patients with recurrent hemarthrosis, laser Doppler flowmetry was used to evaluate resting MC above the index fingers, knee and ankle joints during an occlusion test, with allowance made for muscle and adipose tissue mass.

RESULTS

The increased perfusion value above the afflicted joints was found to correspond to the phase of an exacerbation of posthemorrhagic inflammation and to be a risk factor of recurrent hemarrthrosis. Analysis of the occlusion test above the knee joints and index fingers revealed a diminished MC reserve and a tendency to precapillary spasm. MC changes were more pronounced in a shortage of muscle and adipose tissue mass.

CONCLUSION

Hemophilia patients must regularly do physical exercises to make skeletal muscles develop well in order to prevent an exacerbation of the joint inflammatory process.

Clinical and molecular characterization of a re-established line of sheep exhibiting hemophilia A

BACKGROUND

Large animal models that accurately mimic human hemophilia A (HA) are in great demand for developing and testing novel therapies to treat HA.

OBJECTIVES

To re-establish a line of sheep exhibiting a spontaneous bleeding disorder closely mimicking severe human HA, fully characterize their clinical presentation, and define the molecular basis for disease.

PATIENTS/METHODS

Sequential reproductive manipulations were performed with cryopreserved semen from a deceased affected ram. The resultant animals were examined for hematologic parameters, clinical symptoms, and responsiveness to human FVIII (hFVIII). The full coding region of sheep FVIII mRNA was sequenced to identify the genetic lesion.

RESULTS AND CONCLUSIONS

The combined reproductive technologies yielded 36 carriers and 8 affected animals. The latter had almost non-existent levels of FVIII:C and extremely prolonged aPTT, with otherwise normal hematologic parameters. These animals exhibited bleeding from the umbilical cord, prolonged tail and nail cuticle bleeding time, and multiple episodes of severe spontaneous bleeding, including hemarthroses, muscle hematomas and hematuria, all of which responded to hFVIII. Inhibitors of hFVIII were detected in four treated animals, further establishing the preclinical value of this model. Sequencing identified a premature stop codon and frame-shift in exon 14, providing a molecular explanation for HA. Given the decades of experience using sheep to study both normal physiology and a wide array of diseases and the high homology between human and sheep FVIII, this new model will enable a better understanding of HA and facilitate the development and testing of novel treatments that can directly translate to HA patients.

Cross sectional study to investigate the influence of treatment regimes on the development of haemophilic arthropathy

Haemophilic arthropathy is often present in patients with severe haemophilia. New studies demonstrate that only a small amount and a short exposure of blood in vitro are able to induce an impairment of the joint cartilage. Free blood in the joint leads to different mechanisms and includes cartilage and bone damage induced by a release of macrophages and monocytes followed by activated cytokines and inflammatory processes. Another mechanism is mediated by free iron resulting in synovitis and synovial hyperplasia and a neoangiogenesis on the base of VEGF release is common. At worst, these processes result in a complete picture of haemophilic arthropathy reducing quality of life. Few studies are available about the influence of factor treatment regime, e. g. prophylaxis or on-demand therapy, on the development of haemophilic arthropathy. However these studies investigated in most cases children. Therefore, it is still impossible to give recommendations for the right treatment in adult haemophilic patients because data are still lacking. For that reason, we attempt to initiate the HemArthro-Project to investigate the influence of treatment therapy on the development of arthropathy in adult haemophilic patients. This study includes the investigation of functional musculoskeletal parameters for the description of joint function in maximal 500 severe haemophilic patients parted into two groups of treatment regime (prophylaxis vs. on-demand). The investigators are seeking further assistance from the haemophilic treatment centers for the support of this study.

[Haemophilia and knee function: are there differences between haemophilic and healthy children?]

With early prophylactic treatment our haemophilic children grow up in good health. Nevertheless, we cannot prevent every bleeding. Those bleedings may be just subclinical but they could lead to overloading of the knee and more and more of the ankle joint in the long term. Motion analysis can help to understand this process and prevent it. A comparison of the gait function of haemophilic and healthy children of the age 3-18 years showed distinct functional differences especially in the youngest age group (3-6 years). Apparently, the coordination skill gait rhythm was significantly worse in the heamophilic group. All measured functional deficits can be treated with physiotherapy. Possible reasons for these early functional differences are overprotection and/or early subclinical bleedings.

Hemostatic effect of recombinant factor VIIa, NN1731 and recombinant factor VIII on needle-induced joint bleeding in hemophilia A mice

BACKGROUND

Hemophilia A is the most common serious bleeding disorder, and the hallmark of this disease is joint bleeding episodes. These result in hemophilic synovitis, an inflammatory and proliferative condition of the joint, which progresses into a chronic degenerative arthritis, hemophilic arthropathy.

METHODS

In this paper, we describe the effect of recombinant factor VIIa (rFVIIa), and an analogue NN1731 as well as rFVIII on needle-induced bleeding in hemophilia A mice.

CONCLUSIONS

Here we show a reducing effect of rFVIIa and NN1731 on bleeding induced in hemophilic mice, and we show that preventive treatment with rFVIII normalizes bleeding.

Isolation and characterization of connective tissue progenitor cells derived from human fracture-induced hemarthrosis in vitro

In our search for alternative sources of connective tissue progenitor cells that can be obtained with minimal invasion, we studied human intraarticular fracture-induced hemarthrosis of the knee and attempted to isolate connective tissue progenitors from the hemarthrosis. Hemarthrosis was aspirated from the knee joints of 13 patients suffering from intraarticular osteochondral fractures of the knee. Mononuclear cells were isolated from the aspirated hemarthrosis by density gradient separation, and cultured. We were able to obtain fibroblastic adherent cells from the mononuclear cell fractions. Flow cytometry analysis after in vitro expansion on tissue culture plastic revealed that the fibroblastic cells were positive for CD29, CD44, CD105, and CD166, and negative for CD14, CD34, CD45, and CD133. These cells could differentiate in vitro into osteogenic, chondrogenic, and adipogenic cells in the presence of lineage-specific induction factors. These results demonstrate that human intraarticular fracture-induced knee hemarthrosis contains connective tissue progenitor cells with morphologic features, immunophenotypic markers, and differentiation potential that are similar to bone marrow stromal cells. This suggests that hemarthrosis, which is easy to harvest without unnecessary invasion to the patient, has possible future clinical applications such as in tissue-engineered therapies for severe osteochondral defects, posttraumatic osteoarthritis, and delayed fracture unions or nonunions.

Magnetic resonance imaging findings of temporomandibular joint soft tissue changes in type V and VI condylar injuries

PURPOSE

The objective of this study was to describe the incidence of acute temporomandibular joint (TMJ) soft tissue lesions associated with the occurrence of type V (high condylar fractures with dislocation) and type VI condylar fractures (condylar head fractures).

PATIENTS AND METHODS

The study comprised 11 consecutive patients, who were assigned a diagnosis of a uni- or bilateral type V or type VI condylar fracture. Bilateral sagittal and coronal magnetic resonance (MR) images were obtained immediately after injury to establish the presence or absence of disc disruption, capsular tear, retrodiskal tissue tear, and hemarthrosis.

RESULTS

There was 1 condylar fracture site showing signs of disc disruption (16.7%). Tears in the capsule and retrodiscal tissue were found with an incidence of 77% and 71%, respectively, while the incidence of hemarthrosis accounted for 100%. MR imaging failed to show any signs of soft tissue lesions for condylar nonfracture sites.

CONCLUSIONS

Type V and type VI condylar fracture sites are associated with a high incidence of injuries to the joint capsule and retrodiscal tissue. Investigation of longitudinal evidence, including risk factors, natural history, and response to treatment appears warranted and necessary.

Oxidant and anti-oxidant systems of synovial fluid from patients with knee post-traumatic arthritis

It has been suggested that patients with knee post-traumatic arthritis (PA), associated or not to haemarthrosis (HA), display altered oxidant and anti-oxidant systems in their synovial fluid. This study aimed to establish whether this is really the case. Synovial fluid samples were obtained by transdermal arthrocentesis from 69 patients with PA (36 of them had HA) and 22 control subjects. The activities of synovial fluid zinc-copper superoxide dismutase (ZnCuSOD) and manganese superoxide dismutase (MnSOD) isoenzymes, catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR) and glutathione-S-transferase (GST) enzymes, and malondialdehyde (MDA) concentration and synovial fluid viscosity were measured in the study groups. Patients with PA had significantly increased activities of all antioxidant enzymes, except CAT, and MDA concentration than did the controls. However, synovial fluid viscosity was found to be decreased in the study group, mainly in the HA subgroup. Results suggest that excessive free radicals production may exist in synovial fluid of PA patients and may contribute to knee joint destruction.

Histological changes in murine haemophilic synovitis: a quantitative grading system to assess blood-induced synovitis

Haemophilia is a congenital disorder that results in frequent bleeding into joints, in which a chronic and debilitating arthritis develops. The presence of blood evokes an inflammatory and proliferative synovial reaction. Although the molecular mechanisms and biochemical pathways which underlie this disorder are not known, significant advances have been made by studying a murine model of human haemophilic synovitis. In order to better understand and correlate the pathological, molecular and biochemical changes, it has become necessary to grade the histological changes observed. Despite a search of the literature and review of relevant publications, none of the currently utilized schemes were appropriate, and therefore a novel grading scheme was developed. After review of over 1000 histological sections, six characteristic changes were identified: (i) synovial hyperplasia; (ii) vascularity; (iii) discolouration by haemosiderin; (iv) the presence of blood (erythrocytes); (v) villus formation; and (vi) cartilage erosion. Synovial hyperplasia and vascularity were present in variable amounts and were quantitatively scored (0-3), while the other changes were qualitatively scored as absent or present (0 or 1). Application of the grading scheme was tested and a high interobserver correlation (greater than 80%) was found. The scheme was easy to learn even by novices, with no prior experience. The availability of the histological grading scheme for murine synovitis will allow for precise evaluation of the pathological changes following joint bleeding, and facilitate correlations with molecular and biochemical changes that lead to these changes.

In vitro multipotentiality and characterization of human unfractured traumatic hemarthrosis-derived progenitor cells: A potential cell source for tissue repair

Mesenchymal progenitor cells (MPCs) are a very attractive tool in the context of repair and regeneration of musculoskeletal tissue damaged by trauma. The most common source of MPCs to date has been the bone marrow, but aspirating bone marrow from the patient is an invasive procedure. In an attempt to search for alternative sources of MPCs that could be obtained with minimal invasion, we looked into traumatic hemarthrosis of the knee. In this study, we determined whether a population of multipotent MPCs could be isolated from acute traumatic knee hemarthrosis in the absence of intra-articular fractures. Mononuclear cells were isolated from the aspirated hemarthrosis by density gradient separation, and cultured. We were able to obtain plastic adherent fibroblast-like cells from the mononuclear cell fractions. Flow cytometry analysis revealed that the adherent fibroblast-like cells were consistently positive for CD29, CD44, CD105, and CD166, and were negative for CD14, CD34, and CD45. These were similar to control bone marrow stromal cells. These cells could differentiate in vitro into osteogenic, adipogenic, and chondrogenic cells in the presence of lineage-specific induction factors. In conclusion, acute unfractured traumatic hemarthrosis of the knee contains MPCs with multipotentiality. Because knee hemarthrosis is easy to harvest with minimal pain and without unnecessary invasion, we regard hemarthrosis-derived cells as an additional progenitor cell source for future tissue engineering and cell-based therapy in knee injuries.

Condylar injury: magnetic resonance imaging findings of temporomandibular joint soft-tissue changes

Recent studies have suggested magnetic resonance imaging (MRI) as useful in the evaluation of soft-tissue changes that occur in the temporomandibular joint (TMJ) after acute condylar trauma. The aim of this study was to investigate whether MRI findings of disc displacement, capsular tear and haemarthrosis are linked to the degree of condylar injury. Nineteen patients were assigned a diagnosis of uni- or bilateral condylar fracture (n=17), or condylar contusion with a uni- or bilateral diagnosis of TMJ sprain/strain (n=2). Condylar injuries were classified as grade I (absence of condylar fracture), grade II (type I, II or III condylar fracture), and grade III (type IV, V or VI condylar fracture). Bilateral sagittal and coronal MR images were obtained immediately after injury to establish the presence or absence of disc displacement, haemarthrosis and capsular tear. The data revealed a significant relationship between the degree of condylar injury and the MRI findings of capsular tear (P=0.000) and haemarthrosis (P=0.000), and between the MRI diagnoses of capsular tear and haemarthrosis (P=0.000). There was good diagnostic agreement between the presence of grade III condylar injury and the MRI diagnoses of capsular tear (K=0.62) and haemarthrosis (K=0.60). The results suggest that degree of condylar injury is related to MRI findings of capsular tear and haemarthrosis, and that MRI to supplement diagnosis of grade III condylar injury is warranted.

A case of spontaneous hemoarthrosis after a total knee arthroplasty

A 63-year-old woman with osteoarthritis had undergone right total knee arthroplasty. Nineteen months later, the patient presented with a recurrent hemoarthrosis. Open arthrotomy revealed hypertrophic synovium with small clots in the suprapatellar pouch, but entrapment of synovial tissues could not be observed. Histological examination of the extirpated specimen showed fibrous hypertrophy of synovium. The patient has no symptoms 51 months after surgery.

Reliability and construct validity of the compatible MRI scoring system for evaluation of haemophilic knees and ankles of haemophilic children. Expert MRI working group of the international prophylaxis study group

We tested the reliability and construct validity of the Compatible magnetic resonance imaging (MRI) scale for the evaluation of haemophilic knees and ankles and compared the diagnostic performance of MRI and plain film radiographs. Sagittal and coronal gradient-echo 1.5-T MR images of knees (n=22) and ankles (n=23) were obtained from boys (age range 4-16 years; mean 11 years) in two centres (Toronto, n=26; Europe, n=19). The MR images were independently read by four blinded radiologists on two occasions. Number of previous joint bleedings and laboratory level of severity of haemophilia were the reference standards for imaging assessment. Both components of the MRI scale demonstrated high inter- and intrareader intraclass correlation coefficients (progressive (P) scale, 0.91 and 0.94; additive (A) scale, 0.81 and 0.92 respectively). The correlation between the osteochondral domain of the MRI scale and patient's age was moderate. Otherwise, correlations between A- and P-scales and clinical laboratory measurements were weak. The areas under the curve (AUCs) used for discrimination of disease severity were similar for the A- and P-scales (AUCs used for mild disease, A-scale, 0.72+/-0.07; P-scale, 0.69+/-0.08; P=0.23; AUCs for severe disease, A-scale, 0.93+/-0.05; P-scale, 0.87+/-0.08; P=0.05). No differences were noted between the AUCs of the MRI and radiographic scales used for discrimination of late osteoarticular changes; MRI scales performed better for discrimination of early changes. In conclusion, both MRI scales demonstrated excellent reliability, poor convergent validity, and moderate and excellent validity for discrimination of mild and severe diseases respectively. Compared with radiographic scores, the MRI scales performed better for discrimination of early osteoarticular changes.

Tailored prophylaxis in severe hemophilia A: interim results from the first 5 years of the Canadian Hemophilia Primary Prophylaxis Study

BACKGROUND

Prophylactic treatment for severe hemophilia A is likely to be more effective than treatment when bleeding occurs, however, prophylaxis is costly. We studied an inception cohort of 25 boys using a tailored prophylaxis approach to see if clotting factor use could be reduced with acceptable outcomes.

METHODS

Ten Canadian centers enrolled subjects in this 5-year study. Children were followed every 3 months at a comprehensive care hemophilia clinic. They were initially treated with once-weekly clotting factor; the frequency was escalated in a stepwise fashion if unacceptable bleeding occurred. Bleeding frequency, target joint development, physiotherapy and radiographic outcomes, as well as resource utilization, were determined prospectively.

RESULTS

The median follow-up time was 4.1 years (total 96.9 person-years). The median time to escalate to twice-weekly therapy was 3.42 years (lower 95% confidence limit 2.05 years). Nine subjects developed target joints at a rate of 0.09 per person-year. There was an average of 1.2 joint bleeds per person-year. The cohort consumed on average 3656 IU kg(-1)year(-1) of factor (F) VIII. Ten subjects required central venous catheters (three while on study); no complications of these devices were seen. One subject developed a transient FVIII inhibitor. End-of-study joint examination scores--both clinically and radiographically--were normal or near-normal.

CONCLUSIONS

Most boys with severe hemophilia A will probably have little bleeding and good joint function with tailored prophylaxis, while infusing less FVIII than usually required for traditional prophylaxis.

Comparative study of validity of clinical, X-ray and magnetic resonance imaging scores in evaluation and management of haemophilic arthropathy in children

To evaluate joints alterations, we performed clinical examination, X-rays and magnetic resonance imaging (MRI) (Denver score) in 165 joints of 40 children with severe (n, 32) or moderate (n, 8) haemophilia A or B. All investigated joints had a history of more than three bleeds. At evaluation, 25 of 40 haemophilic patients were on prophylaxis for the last 1-8 years (mean: 3.5 years). MRI revealed chronic synovitis in 55.4% and 50% of joints, which were diagnosed, as normal by the clinical scale and plain radiography respectively. Moreover, MRI unmasked more profound alterations than those observed by plain radiography in 70% of cases. Statistical analysis showed that the clinical and Pettersson scores in contrast to the Denver score provide an underestimation of arthritic changes. Besides, Denver score did not provide resolution in differentiating stages of arthropathy, because of its inherent nature; however, a score of 6 expressing severe synovitis seemed to be the cut-off value for the distinction of severe cases. Based on MRI findings we intensified prophylaxis in nine children and initiated it in another nine children. Five children, who were already on prophylaxis complied with our recommendations and eliminated haemorrhages. Finally, three boys with severe haemophilic arthropathy in knees underwent successful chemical synovectomy with rifampicin.

Osteogenic potential of cells in vitro derived from haemarthrosis of the knee induced by injury to the anterior cruciate ligament

We have investigated whether cells derived from haemarthrosis caused by injury to the anterior cruciate ligament could differentiate into the osteoblast lineage in vitro. Haemarthroses associated with anterior cruciate ligament injuries were aspirated and cultured. After treatment with beta-glycerophosphate, ascorbic acid and dexamethasone or 1,25 (OH)(2)D(3), a significant increase in the activity of alkaline phosphatase was observed. Matrix mineralisation was demonstrated after 28 days and mRNA levels in osteoblast-related genes were enhanced. Our results suggest that the haemarthrosis induced by injury to the anterior cruciate ligament contains osteoprogenitor cells and is a potential alternative source for cell-based treatment in such injury.

Human hemarthrosis-derived progenitor cells can differentiate into osteoblast-like cells in vitro

We hypothesized that intraarticular osteochondral fracture-induced hemarthrosis could be a useful cell source for bone regeneration, as it is thought to contain osteoprogenitor cells derived from bone marrow. Therefore, we investigated whether human hemarthrosis-derived cells have the potential to differentiate into osteoblast-like cells in vitro. We aspirated hemarthrosis from patients suffering from osteochondral fractures of knee joints, and cultured hemarthrosis-derived cells in a medium supplemented with dexamethasone, beta-glycerophosphate, and ascorbic acid, or without them as control. The morphology of the treated cells appeared to be cuboidal shape, differing from spindle-like shape observed in the control. Matrix mineralization was observed only in the treated culture. Alkaline phosphatase activity and gene expression of alkaline phosphatase, parathyroid hormone receptor, osteopontin, and osteocalcin were up-regulated compared with the control. These studies demonstrate that human hemarthrosis-derived cells can differentiate into osteoblast-like cells, i.e., they contain osteoprogenitor cells and are a useful cell source for bone regeneration.

Synovitis in a murine model of human factor VIII deficiency

Recurrent joint bleeding is the most common musculoskeletal manifestation of haemophilia and leads to a target joint and synovitis. The pathobiology of haemophilic synovitis (HS) is not well understood. Here the histopathological changes that occur following haemarthrosis were examined in an animal model for human HS. After two haemarthrosis, there was soft tissue and joint swelling and histological changes of acute synovitis included infiltration of the sub-synovial layer by mononuclear cells and neutrophils, thickening of the synovial membrane with villus formation, and hyperplasia of blood vessels. Subacute changes were evident after three haemarthrosis; muscle atrophy was present and an intense mononuclear cell infiltrate filled the sub-synovial space. There was destruction of articular surfaces and loss of cartilage. Seventeen months after three haemarthrosis, chronic joint changes included gross deformity and loss of congruence due to dense fibrotic tissue filling the joint space. The mononuclear inflammatory cell infiltrate and thickened synovial membrane persisted. Pits and erosions of articular surfaces and sub-chondral cysts were present. There was fibro-cartilage and new bone formation. This model of human HS should be useful to fully evaluate the biochemical and molecular changes that occur following joint bleeding and to test novel therapeutics to prevent HS.

MRI scores of ankle joints in children with haemophilia--comparison with clinical data

Fifty-six ankle joints in 38 haemophilic boys were investigated by magnetic resonance imaging (MRI) and the findings were classified according to both the Denver- and the European scoring schemes. The different MRI scores were compared with each other and with clinical data on number of joint bleeds and the orthopaedic joint score. MRI changes that were more advanced than a small effusion were found in 33 (59%) of the ankles and osteochondral changes were observed in 20 (36%). The total number of bleeds in individual ankles ranged from 0 to 80 (mean: 11). The orthopaedic joint score was 0 for 49 ankles and ranged from one to four for seven ankles. There was a significant and strong correlation between the assessment results obtained with the two MRI scoring methods (correlation coefficients ranged from 0.80 to 0.95, P < 0.001), and both types of MRI scores were weakly but significantly correlated with the clinical data on the number of joint bleeds and the orthopaedic joint score (correlation coefficients: 0.32-0.39, P < 0.01 or P < 0.05). MRI is useful for evaluating early joint changes in patients with haemophilia. The European scoring method differentiates the arthropathic changes further than the Denver scale does, but the two different scoring methods have similar correlation to the number of joint bleeds and the orthopaedic joint score.

Reliability of progressive and additive MRI scoring systems for evaluation of haemophilic arthropathy in children: Expert MRI Working Group of the International Prophylaxis Study Group

Effective treatment of haemophilic arthropathy requires a detailed evaluation of joint integrity. Methodological assessment of magnetic resonance imaging (MRI) scores are needed to assure reproducibility of measurements when comparing results of clinical trials conducted in different centres. We compared the reliability of two MRI scoring systems for assessment of haemophilic arthropathy: one progressive system that displays the most severe change and one additive system that depicts osteochondral and soft tissue-related changes. A total of 47 1.5 T MRI examinations of knees (n = 21) and ankles (n = 26) of 42 haemophilic boys, age range, 22 months to 18 years, performed at different centres (Toronto, n = 20, Europe, n = 12 and Denver, n = 15) were independently reviewed by four radiologists at two occasions. Twenty-two examinations were from children <9 years and 25 from children >/=9. Sagittal and coronal gradient-echo (MPGR, 3D FLASH with fat saturation, GRASS) images were obtained. The MRI examinations of the ankle and knee studies presented with osteochondral abnormalities in 38.5% and 23.8% of the cases respectively. The two scoring systems demonstrated an excellent inter-reader [progressive, 0.88; additive (A, e, s and h components), 0.86] and intra-reader [progressive, 0.92; additive (A, e, s and h components), 0.93] reliability using intraclass correlation coefficients (ICCs). Although ICCs were slightly higher for knees when compared with ankles, and for older children when compared with younger children, all values fell within excellent inter- and intra-reader reliability categories. The two MRI scoring systems demonstrated a comparable reliability. This result constitutes the basis for further development of a combined MRI scoring system for assessment of haemophilic arthropathy, which incorporates progressive and additive components.

Compatible scales for progressive and additive MRI assessments of haemophilic arthropathy

The international MRI expert subgroup of the International Prophylaxis Study Group (IPSG) has developed a consensus for magnetic resonance imaging (MRI) scales for assessment of haemophilic arthropathy. A MRI scoring scheme including a 10 step progressive scale and a 20 step additive scale with identical definitions of mutual steps is presented. Using the progressive scale, effusion/haemarthrosis can correspond to progressive scores of 1, 2, or 3, and synovial hypertrophy and/or haemosiderin deposition to 4, 5, or 6. The progressive score can be 7 or 8 if there are subchondral cysts and/or surface erosions, and it is 9 or 10 if there is loss of cartilage. Using the additive scale, synovial hypertrophy contributes 1-3 points to the additive score and haemosiderin deposition contributes 1 point. For osteochondral changes, 16 statements are evaluated as to whether they are true or false, and each true statement contributes 1 point to the additive score. The use of these two compatible scales for progressive and additive MRI assessments can facilitate international comparison of data and enhance the accumulation of experience on MRI scoring of haemophilic arthropathy.

Assessment of blood-induced cartilage damage in rabbit knees using scanning electron microscopy

PURPOSE

To investigate the harmful effects of a single episode of intra-articular bleeding on articular cartilage of rabbit knees using scanning electron microscopy.

METHODS

Autologous blood was injected into the right knee joints of 18 New Zealand white rabbits. Surface and cellular damages were examined by the scanning electron microscope (n=9) and light microscope (n=34), respectively. The injected right knees were then compared with the corresponding control left knees at one, 3, and 6 weeks after the blood injection.

RESULTS

The articular surface of the injected knees turned uniformly rough with multiple pits after one week. Maximal changes with elevations and depressions were observed at 3 weeks. These changes reversed at 6 weeks with the irregularities smoothing out. A similar pattern of transient cartilage damage was noted histologically.

CONCLUSION

Both scanning electron microscopic and light microscopic findings suggest that a single episode of intra-articular bleeding leads to articular cartilage damage but this appears to be reversible. Our findings of transient damage to the articular cartilage suggest that there is no need for intra-articular evacuation and washout following an acute episode of haemarthrosis.

Arthroscopic synovectomy for hemophilic joint disease in a pediatric population

Children with hemophilia can develop progressive arthropathy. Arthroscopic synovectomy has been used to reduce hemarthroses, but few long-term results have been published. In this article the authors review their first 12 years of experience. Data are reported on 44 pediatric patients (69 joints: 39 ankles, 21 elbows, 7 knees, 2 shoulders). The median age at surgery was 10 years Median follow-up was 79 months. Joints with sufficient follow-up data showed a median bleeding frequency decline of 84% (P < 0.001). Median arc of motion was stable or improved in the year after surgery in ankles, elbows, and shoulders. Complications were rare. Radiographic scores worsened slightly. In this largest analysis of arthroscopic synovectomy for children with hemophilia, rehabilitation was not problematic.

Safe extracapsular placement of proximal tibia transfixation pins

OBJECTIVE

To identify the anatomic detail of the knee joint capsular insertion site on the proximal tibia, specifically as it relates to transfixation pins.

DESIGN

Identification of capsular anatomy by anatomical dissection of cadaveric specimens, with radiography and arthroscopy of patients.

SETTING

Cadaveric dissection.

OUTCOME MEASURES

Anatomic observation of the capsular attachment site in relation to the tibial articular surface.

RESULTS

The capsule inserts four to fourteen millimeters below the articular surface in a regular pattern. The anterior half of the circumference is close to the joint line (less than six millimeters). Posteromedially and posterolaterally, there are extensions distally to fourteen millimeters, occasionally communicating with the tibiofibular joint.

CONCLUSION

Transfixing wires and half-pins can be placed in the proximal tibia without capsular penetration if kept more than fourteen millimeters from the subchondral line. If wire placement closer to the joint is required, wires should be placed in Zone 1 (the anterior half) and at least six millimeters from subchondral bone to avoid capsular penetration.

Experimental haemophilic synovitis: rationale and development of a murine model of human factor VIII deficiency

Haemophilia is a genetic disease as a result of the deficiency of blood coagulation factor VIII or IX. Bleeding is common, especially into joints where an inflammatory, proliferative synovitis develops resulting in a debilitating arthritis, haemophilic arthropathy. The pathogenesis of blood-induced haemophilic synovitis (HS) is poorly understood. The gross, microscopic and ultrastructural changes that occur in the synovial membrane following human and experimental hemarthrosis have been described. Repeated episodes of bleeding induce synoviocyte hypertrophy and hyperplasia, an intense neovascular response and inflammation of the synovial membrane. The component(s) in blood that initiates these changes is(are) not known, although iron is often proposed as one possibility. Here, we describe a novel murine model of human haemophilia A, which facilitates the examination of large number of animals and tissue specimens. The effects of hemarthrosis on the physical, gross and microscopic changes evoked following joint bleeding are described. Controlled, blunt trauma to the knee joint consistently resulted in joint swelling because of a combination of bleeding and inflammation. Hemosiderin was found in the synovial membrane. Similar to hemarthrosis in human haemophilia, joint bleeding resulted in acute morbidity evidenced by inactivity, weight loss and immobility. With time the animals recovered. The model of experimental murine HS described here has utility in the study of the pathogenesis of HS. This is the first of a series of articles, which will discuss the pathophysiology and characterize the model, with comparison of his model to others which have been published previously. It should provide a useful model to test potential therapeutic interventions.

Imaging of musculoskeletal complications of hemophilia

In patients with hemophilia, hemarthrosis often occurs in one or several joints and may progress to a destructive, disabling arthropathy. Treatment includes continuous or on-demand clotting factor replacement and radionuclide or open synovectomy. The radiographic findings of hemophilic arthropathy depend on the stage of disease, the age of the patient at onset, and the joint involved. These findings include joint effusion, soft tissue swelling, epiphyseal overgrowth, subchondral cysts, osseous erosion, and secondary degenerative changes. Magnetic resonance imaging (MRI) is the most accurate imaging modality for assessing hemophilic arthropathy and may have a significant impact on patient management. MRI is anticipated to be useful in documenting early joint changes when treatment may be most effective. Hemophilic pseudotumor is a chronic, encapsulated, hemorrhagic fluid collection that usually destroys bone and may become quite large. Both computed tomography and MRI are useful in determining the extent of this lesion.

Activated PMNs lead to oxidative stress on chondrocytes: a study of swine knees

Using an in vitro model, based on primary cultured chondrocytes, we examined possible oxidative injury caused by activated polymorphonuclear neutrophil granulocytes (PMNs), which are thought to be part of the pathomechanism of hemarthrosis. Chondrocytes were isolated from swine knee joints and divided into three groups. Pure chondrocytes acted as the control population (group I). PMNs from the systemic circulation, and hydrogen peroxide (as an artificial source of reactive oxygen species (ROS)) were added to groups II and III, respectively. All cultures were incubated for 6 hours. After the experiment, lipid membrane degradation by ROS was assessed by monitoring changes in the levels of malondialdehyde (MDA) and 4-hydroxyalkenal contents of the chondrocyte specimens. Changes in the endogenous scavenger status of the chondrocytes were characterized by measuring of reductions in glutathione (GSH) concentration and superoxide dismutase (SOD) activity. Significant increases in MDA/4-hydroxyalkenal levels and SOD activity as well as an expressive reduction in intracellular GSH content were highlighted by comparing the control to the PMN- or H2O2-treated cell populations. These findings confirm previous suggestions that PMN-derived ROS contribute to degradation of cartilage in hemarthrosis.

Orthopaedic surgery in persons with haemophilia

The orthopaedic problems of haemophilia and the surgical techniques most frequently performed by orthopaedic surgeons on haemophilia patients are summarised in this review article. Sometimes it can be recommendable to carry out two or three orthopaedic surgical procedures in a single operative session, with the aim of solving the functional problem in a more global way, which usually is polyarticular. There is no doubt that such an undertaking implies a greater anaesthetic risk, but also avoids the repetition of surgical procedures and saves factor consumption. Close cooperation between haematologists, orthopaedic surgeons, rehabilitation physicians, paediatricians, psychologists, physiotherapists and nurses is paramount for the satisfactory result of any orthopaedic surgical procedure. There is no doubt that continuous prophylactic clotting factor replacement (prophylactic therapy) is the optimal way to avoid the orthopaedic problems of haemophilia that can still be seen today. Until such a goal can be reached, the orthopaedic surgeon will continue performing arthrocentheses, synoviortheses, synovectomies, tendon lengthenings, débridements, osteotomies, joint replacements, osteosynthesis of fractures and other less frequent surgical procedures on persons with haemophilia.

Hemophilic arthropathy. A scoring system for magnetic resonance imaging

The aim of this study was to define a system for scoring hemophilic arthropathy (HA) based on MR findings, providing for objective evaluation of the degree of joint involvement and evolution after on-demand administration of FVIII substitutional therapy or prophylactic treatment. A total of 133 MR examinations (89 basal and 44 during follow-up) were performed in 25 patients. Patients were divided in two groups depending on the therapy received and the length of time that the disease had been evolving at the start of the study. Group I was composed of 10 patients with secondary prophylaxis and group II was composed by 15 treated on demand. T1-weighted and T2*-weighted images performed on a 0.5-T unit were prospectively evaluated. The joint involvement was established on a scale of 0 (no abnormalities), I (minimal amount of hemosiderin), II (large amount of hemosiderin and isolated cartilaginous erosion), III (cartilage destruction, bone erosions, and subchondral cysts) to IV (large internal joint derangement, secondary osteoarthritis and/or ankylosis). At basal MR examination, patients of group I showed no abnormalities ( n=28, 75.6%), grade I ( n=3), and grade II ( n=6) of HA. Patients of group II corresponded to MR grades III ( n=21) and IV ( n=11) of HA. The MR follow-up showed improvement in three joints of group I and worsening in 5 joints in group I and 2 joints in group II. Early signs of HA were detected in 10 joints with MR imaging but were underestimated on plain radiographs. Advanced degrees of HA were classified as severe under both imaging techniques. Magnetic resonance is the preferred imaging technique to assess HA. The earliest signs of joint damage, detected by MR, are overlooked by plain radiography. The MR scoring system can be used for evaluating HA. Follow-up MR should be performed to evaluate regression or worsening of the abnormalities, primarily in the case of patients with prophylaxis who usually suffer normal or early joint involvement not detected by other means.

Hemarthrosis: an unusual complication of type 1 neurofibromatosis

Type 1 neurofibromatosis is one of the most common autosomal-dominant disorders and often includes orthopedic manifestations. We report the case of a 48-year-old woman with hemarthrosis caused by a popliteal cyst infiltrated by a diffuse neurofibroma associated with angiodysplasia. Surgical resection of this tumor was followed by postoperative hemorrhagic complications.

The history of synoviorthesis in haemophilia

The history of synoviorthesis and recent studies have shown that it is a safe procedure and that the results are similar to those seen following open surgical and arthroscopic synovectomy. If the safety of this procedure is definitively proven in long-term studies it will become the procedure of choice for treatment of recurrent haemarthroses and synovitis. That is, until the time when the haematologists and geneticists eliminate the need for orthopaedic intervention in the care of persons with haemophilia.

Correlation between clinical, radiological and ultrasonographical image of knee joints in children with haemophilia

The aims of the study were to evaluate the clinical, radiological and ultrasonographical images of knee joints in children with severe haemophilia and von Willebrand's disease, to determine the correlation between these images and to assess the usefulness of ultrasonography (USG) in evaluating the intensity of haemophilic arthropathy. Thirty-nine boys were included in the study, all of them with a past history of knee bleeds. The average age of the children was 10.02 +/- 3.01 years. In patients with slight (1-3 points) and moderate (4-7 points) radiological changes in knee joint bones, an increase in synovial fluid, considerable hypertrophy and inflammation of the synovium were observed in USG. In haemophilic patients with severe (8-13 points) bone changes, the amount of fluid was usually normal and there was slight inflammation but considerable hypertrophy of the synovium. Radiological evaluation of haemophilic arthropathy was made according to the Pettersson classification. A good correlation between the degree of cartilage damage in USG and the progression of bone changes in radiographs was found. Cartilage and bone damage progressed with the increase in the number of intra-articular haemorrhages into the knee joint. In our opinion USG is useful in evaluating the fluid, synovium and cartilage of joints in haemophiliacs.

Successful arthroscopic treatment of pigmented villonodular synovitis of the knee in a patient with congenital deficiency of plasminogen activator inhibitor-1 and recurrent haemarthrosis

We report the arthroscopic treatment of pigmented villonodular synovitis (PVNS) in a 13-year-old Japanese boy with congenital partial deficiency of plasminogen activator inhibitor-1 (PAI-1). He was admitted to our hospital with recurrent haemarthrosis of his right knee. Characteristic abnormalities of fibrinolysis included shortened euglobulin lysis time, low PAI-1 activity and low PAI-1 antigen levels. In addition, levels of "active PAI" in the plasma, which is a measure of total PAI bound to exogenous plasminogen activator, were very low. These parameters remained low after venous occlusion. The diagnosis of PVNS was established by synovial membrane biopsy, and arthroscopic synovectomy was performed with adjuvant administration of intravenous tranexamic acid. Subsequent bleeding episodes have been well controlled by oral administration of tranexamic acid on demand.

Osteoarticular disorders of haematological origin

Clinical abnormalities of the musculoskeletal system may be the first manifestation of sickle haemoglobinopathies, leukaemias, lymphomas and haemophilia. In addition to this, known patients with these diseases exhibit a variety of osteoarticular features. The painful crisis is the most common manifestation of sickle cell disorders, but avascular necrosis, osteomyelitis and various forms of arthritides are also common. In haematological malignancies, bone pain and arthritis may occur at any stage of the disease. The diagnosis must be confirmed by the presence of malignant cells on histological examination of various samples. Haemarthrosis is the main symptom of haemophilia. It needs early treatment to avoid damage to the joints. The availability of new safe coagulation factors has improved the prognosis of haemophilia.