Exploring the biological basis of haemophilic joint disease: experimental studies

Iron overload causes macrophages to produce a pro-inflammatory phenotype in the synovium of hemophiliac arthritis via the acetyl-p53 pathway

AIM

Haemophiliac arthritis (HA) is caused by spontaneous intra-articular hemorrhage and repeated intra-articular hematomas, leading to iron overload, which, in turn, induces M1 macrophage polarisation and inflammatory cytokine secretion, resulting in synovitis. Here, we explored the mechanism by which iron overload in HA induces the polarisation of M1 macrophages, providing a new approach for the treatment of HA synovitis.

METHODS

The synovium from the knee joints of normal amputees and patients with HA was collected. Pathological changes in the synovial tissues were analysed using hematoxylin and eosin staining. Iron tissue deposition was evaluated using the iron assay kit and Prussia Blue staining, while macrophage phenotype was determined using immunofluorescence. The levels of pro-inflammatory cytokines and p53 acetylation were determine using western blotting. An in vitro iron overload model was established by inducing THP-1 macrophages with ferric ammonium citrate, and the involvement of acetylated p53 in M1 macrophage polarisation was investigated.

RESULTS

Compared to control samples, the iron content in the synovium of patients with HA was significantly increased. The protein levels of M1 macrophage markers, pro-inflammatory cytokines, and acetylated p53, were also significantly elevated in the synovial tissues of patients with HA. Similar results were observed in the in vitro iron overload model. Furthermore, the inhibition of p53 acetylation in vitro reversed these iron overload-induced effects.

CONCLUSION

In patients with HA, iron overload induced synovial p53 acetylation, leading to macrophage polarisation toward the M1 phenotype and increased inflammatory cytokine secretion, resulting in synovitis.

HIGHLIGHTS

Synovial iron overload is associated with changes in P53 acetylation in hemophiliac arthritis (HA). Acetylated p53, a known regulator of macrophage polarization, is highly expressed in HA synovium, suggesting a potential role in M1 polarization. HA synovial macrophages predominantly polarize into the pro-inflammatory M1 phenotype, secreting elevated levels of pro-inflammatory cytokines.

Predicting the development of hemophilic arthropathy in patients with hemophilia based on patient age: a retrospective single-center database study

BACKGROUND

Patients with hemophilia (PWH) develop hemophilic arthropathy of the major joints due to recurrent hemarthrosis. This study retrospectively estimated the age at which PWH may expect to develop hemophilic arthropathy and undergo joint replacement surgery.

RESEARCH DESIGN AND METHODS

Using retrospective data from PWH at a Czech orthopedic center, Kaplan Meier analyses were used to estimate the cumulative proportions of patients with hemophilic arthropathy and undergoing joint replacement surgery as a function of age.

RESULTS

Based on 1028 joint examinations in 167 PWH, hemophilic arthropathy of the knees, elbows, ankles and hips was estimated to develop by a median age of 48, 51, 52 and 61 years, respectively, with ≈80% of patients having such damage by ≈70 years of age. Hemophilic arthropathy of the shoulder occurred much later (median >80 years). In patients undergoing knee or hip replacement surgery, hemophilic arthropathy of the knee and hip occurred at a median age of ≈50 and ≈60 years, respectively, with replacement surgery occurring at a median of ≈70 and >75 years.

CONCLUSIONS

In PWH, the risk of developing hemophilic arthropathy accumulates continuously over the patient's lifetime, allowing predictions about the ages at which such damage and joint replacement surgery may occur.

Intra-articular injection of platelet-rich plasma in patients with hemophilia and painful knee joint cartilage degeneration

INTRODUCTION

Knee arthropathy causes pain to people with hemophilia (PWH). One of the current controversies is whether injections of intra-articular platelet-rich plasma (PRP) are effective in relieving the knee pain of PWH.

AREAS COVERED

A narrative literature review was conducted on the efficacy of PRP injections in the knees of PWH.

EXPERT OPINION

Intra-articular PRP knee injections are widely used in patients with knee osteoarthritis to relieve pain and delay total knee arthroplasty. Although numerous publications have supported the use of PRP in knee osteoarthritis, there is still major controversy regarding its true usefulness, given that a number of studies with a high degree of evidence have failed to show the efficacy of PRP. With respect to painful hemophilic arthropathy, the use of PRP injections is even more controversial, as there are only four publications on the subject supporting the use of PRP in hemophilia, all of them with a low degree of evidence. A publication with grade 1 evidence recommended against the use of PRP in hemophilic arthropathy because its efficacy has not been demonstrated. My opinion is that intra-articular PRP injections should not be used in hemophilia until there is more evidence of its benefits.

The evolution of physiotherapy in the multidisciplinary management of persons with haemophilia (PWH): A scoping review

INTRODUCTION

Haemophilia is a rare congenital bleeding disorder, and the most common manifestation is spontaneous bleeding in muscles and joints. Despite the benefits linked to recent and dramatic pharmacological advances at least in high income setting, many patients still develop musculoskeletal dysfunctions during their lifetime, which must be managed by physiotherapists in the frame of a multidisciplinary team. The aim of the scoping review is to map the available evidence by providing an overview on the past and present physiotherapy scenario in persons with haemophilia (PWH).

MATERIALS AND METHODS

The review was conducted according to the guidelines of the PRISMA extension for scoping reviews. Scientific articles on physiotherapy and sport interventions for PWH published from 1960 up to September 2021 have been included. Search was conducted on the e-databases PubMed and PEDro without restrictions for the study design.

RESULTS

Sixty eight articles were included, 52 related to rehabilitation and preventive physiotherapy, 16 to sport. The results have been reported in chronological order and divided into two categories: (1) rehabilitation and preventive physiotherapy; (2) sport activities.

CONCLUSIONS

This is the first scoping review on physiotherapy in haemophilia, based on the existing evidence on this topic which allowed us to underline how the role of the physiotherapist changed over time. Historically this specialist did intervene only after an acute bleed or surgical operation, but now he has a pivotal role in the multidisciplinary team that acts to improve from birth the quality of life of the PWH. His activity is also closely intertwined with sport promotion and supervision.

Effects of a supervised therapeutic exercise program on musculoskeletal health and gait in patients with haemophilia: A pilot study

INTRODUCTION

Episodes of bleeding in patients with haemophilia (PwH) are associated with haemophilic arthropathy, limitations in physical performance, reduced quality of life (QoL), and gait disorders.

AIM

This non-randomized, controlled, interventional, prospective, single-centre pilot study aimed to assess the effects of an 8-week supervised therapeutic exercise program on musculoskeletal health, gait kinematic parameters (GKP), functional capacity, and QoL in adult PwH.

METHODS

Nineteen PwH were allocated to an exercise group (n = 10) or a control group (n = 9). The patients in the exercise group followed an 8-week supervised therapeutic exercise program. The Haemophilia Joint Health Score (HJHS), a two-dimensional video-based gait kinematic analysis (2D-GKA), the 6-min walking test (6MWT), and the Haemophilia Quality of Life Questionnaire for Adults (Haem-A-Qol) were used as the outcome measures at baseline, after the exercise program (at the 8th week), and at the 6th-month follow-up.

RESULTS

A significant improvement was observed in the exercise group in the HJHS-Total and Haem-A-Qol Total scores and the 6MWT value after the exercise program. Moreover, the 2D-GKA revealed improvement in most of the GKP (knee extension during the midstance and late swing phases, ankle dorsiflexion during the midstance phase, and ankle plantar flexion during the preswing phase). However, the gain obtained by the exercise program was not maintained at the 6th-month follow-up for the HJHS-Total and Hem-A-QoL-Total scores and GKP.

CONCLUSION

The 8-week supervised therapeutic exercise program was successful in achieving improvement in joint health, GKP, functional capacity, and QoL in PwH.

Hemophilic arthropathy: Current knowledge and future perspectives

Hemophilia A and B are rare X-linked inherited bleeding disorders caused by complete or partial deficiency in or the absence of coagulation factors VIII and IX. Recurrent joint bleeding (hemarthrosis) is the most frequent clinical manifestation of severe hemophilia. Unless appropriately managed, even subclinical hemarthrosis can lead to the development of hemophilic arthropathy, a disabling condition characterized by joint remodelling, chronic pain, and a reduced quality of life, and eventually requires joint replacement. Given the lack of specific treatments to reduce blood-induced synovitis, the prevention of bleeding is pivotal to the maintenance of joint health. Prophylactic coagulation factor replacement therapy using extended half-life recombinant drugs has significantly improved patients' quality of life by reducing the burden of intravenous injections, and the more recent introduction of nonreplacement therapies such as subcutaneous emicizumab injections has improved treatment adherence and led to the greater protection of patients with hemophilia A. However, despite these advances, chronic arthropathy is still a significant problem. The introduction of point-of-care ultrasound imaging has improved the diagnosis of acute hemarthrosis and early hemophilic arthropathy, and allowed the better monitoring of progressive joint damage, but further research into the underlying mechanisms of the disease is required to allow the development of more targeted treatment. In the meantime, patient management should be based on the risk factors for the onset and progression of arthropathy of each individual patient, and all patients should be collaboratively cared for by multidisciplinary teams of hematologists, rheumatologists, orthopedic surgeons, and physiotherapists at comprehensive hemophilia treatment centers.

Rehabilitation management of a triceps surae muscle injury in a young male with haemophilia A and high-titre inhibitors

Haemophilia A is a rare inherited hematologic disorder characterized by a deficit of coagulation factor VIII. It is associated with frequent episodes of musculoskeletal bleedings that occur mainly inside joints and secondly inside muscles. The majority of intramuscular hematomas respond well to conservative protocols, based on rehabilitation techniques and appropriate haemostatic coverage; surgery is limited to refractory cases. This manuscript describes the management of an intramuscular bleeding in a young patient with severe haemophilia A and high-titre inhibitors. A multidisciplinary approach directed by a physiatrist and combining surgical intervention, use of bypassing agents and rehabilitation treatment allowed to successfully managing this case, leading to a complete functional recovery. Given the lack of consensus on the treatment of intramuscular bleedings in haemophiliac patients, this case report provides an example of successful management for such conditions, which require a multidisciplinary approach in which the physiatrist plays a key role.

Long-term joint outcomes of regular low-dose prophylaxis in Chinese children with severe haemophilia A

OBJECTIVES

To explore the long-term joint outcomes of low-dose prophylaxis in Chinese children with severe haemophilia A and to analyse their related factors.

METHODS

We retrospectively analysed follow-up data from 21 severe haemophilia A children on regular low-dose prophylaxis for 6-10 years. We used International Prophylaxis Study Group magnetic resonance imaging score (IPSG MRI score), Hemophilia Joint Health Score (HJHS), number of target joints, and Hemophilia-Specific Quality of Life Index (Haemo-QoL) to evaluate joint outcomes. Factors associated with these outcomes were evaluated by statistical analysis.

RESULTS

(1) The children were 1.75 to 17 years age at prophylaxis initiation. Median prophylactic factor VIII dose was 22.9 IU/kg per week. (2) At the end of follow-up: (a) The total IPSG MRI scores were 2-24 with 90.5% children exhibiting moderate to severe joint involvement (score 7-24); (b) The HJHS ranged 2-27, with 0-10 for 46.7% children and >10 for 53.3% children. There was a positive correlation between the MRI score and HJHS (p < .05); (c) Compared to their on-demand treatment period before prophylaxis, target joints numbers decreased, and no child needed auxiliary devices to walk; (d) Joint outcomes were positively correlated with the age at initiation of low-dose prophylaxis (p < .05) and negatively correlated with the treatment dose.

CONCLUSION

Long-term low-dose prophylaxis had positive effect on joint outcomes compared with on-demand treatment. However, a certain degree of joint damage remained in all children indicating the need for improving the current strategy of low-dose prophylaxis.

[Orthopedic treatment of musculoskeletal disorders in hemophilic patients]

Objective: To study the orthopedic treatment strategy for hemophilia complicated with musculoskeletal disorders as well as the peri-operative consumption of clotting factor. Methods: Total 338 orthopedic surgeries were performed for 261 patients, average age of 30.6 y (6-65 y) , with hemophilia between January 1996 and December 2019 at our institute. Two hundred and twenty-six patients presented with bleeds within the joints. Sixty-one patients presented with intramuscular bleeds, 45 presented with hemophilic pseudotumors, and six presented with miscellaneous complaints. Strategy of clotting factor replacement therapy was designed as per differences in the level of the operation procedure. Information regarding clinical manifestation, operative strategy, clotting factor consumption, and re-operation for complications was retrospectively recorded. The costs for multiple joint procedure and single joint procedure were studied. Results: We found that 270 of the 338 surgical procedures were major surgical procedures (79.9%) . There were 203 procedures of joint arthroplasty (60%) . Fourteen patients underwent reoperations for local recurrence (4.2%) . The average factor Ⅷ consumption before the surgery was 44.4 ± 8.1 IU/kg. The average FⅧ consumption within postoperative 2 weeks was 40 962 IU (647±177 IU/kg) . Seven type A hemophilic patients developed F Ⅷ inhibitor following the surgical procedure, with an average level of 13.7±11.2 BU/mL. Sixty-eight patients underwent multiple joint procedures under one anesthesia session (26%) . There was no significant difference in the factor consumption between the multiple joint procedure and single joint procedure. Conclusions: Surgical treatment was found to be effective for hemophilic arthropathy and lesion of the musculoskeletal apparatus, with the clotting factor replacement therapy. Multiple joint procedures under one anesthesia were more cost effective for patients with hemophilia, with less factor consumption than staged single joint procedure.

Initial joint bleed volume in a delayed on-demand treatment setup correlates with subsequent synovial changes in hemophilic mice

BACKGROUND

Hemophilic arthropathy is a debilitating morbidity of hemophilia caused by recurrent joint bleeds. We investigated if the joint bleed volume, before initiation of treatment, was linked to the subsequent degree of histopathological changes and the development of bone pathology in a mouse model of hemophilic arthropathy.

METHODS

FVIII knock-out (F8-KO) mice were dosed with a micro-CT blood pool agent prior to induction of hemarthrosis. Eight hours after induction, the bleed volume was quantified with micro computed tomography (micro-CT) and recombinant FVIII treatment initiated. On Day 8, inflammation in the knees was characterized by fluorescence molecular tomography. On Day 14, knee pathology was characterized by micro-CT and histopathology. In a second study, contrast agent was injected into the knee of wild-type (WT) mice, followed by histopathological evaluation on Day 14.

RESULTS

The average joint bleed volume before treatment was 3.9 mm3. The inflammation-related fluorescent intensities in the injured knees were significantly increased on Day 8. The injured knees had significantly increased synovitis scores, vessel counts, and areas of hemosiderin compared to un-injured knees. However, no cartilage- or bone pathology was observed. The bleed volume before initiation of treatment correlated with the degree of synovitis and was associated with high fluorescent intensity on Day 8. In F8-KO and WT mice, persistence of contrast agent in the joint elicited morphological changes.

CONCLUSION

When applying a delayed on-demand treatment regimen to hemophilic mice subjected to an induced knee hemarthrosis, the degree of histopathological changes on Day 14 reflected the bleed volume prior to initiation of treatment.

Rapid inflammation and early degeneration of bone and cartilage revealed in a time-course study of induced haemarthrosis in haemophilic rats

OBJECTIVES

Detailed knowledge of the sequential cell and tissue responses following haemarthrosis is important for a deep understanding of the pathological process initiated upon extensive bleeding into the joint causing haemophilic arthropathy (HA). The underlying pathobiology driving haemarthrosis towards HA has been difficult to establish in detail, although animal models have shed light on some processes. Previous studies have focused on a single or a few distant time points and often only characterizing one tissue type of the joint. The objective of this study was, therefore, to carefully map early onset of synovitis and HA following induced haemarthrosis.

METHODS

One hundred and thirty haemophilia A rats were subjected to induced haemarthrosis or a sham procedure in full anaesthesia and euthanized from 30 min to 7 days after the procedure. Pathological changes of the joints were visualized using micro-computed tomography, histology and immunohistochemistry.

RESULTS

Synovitis developed within 24 h and was dominated by myeloid cell infiltrations. Cartilage and bone pathology were evident as early as 48-96 h after haemarthrosis, and the pathology rapidly progressed with extensive periosteal bone formation and formation of subchondral cysts.

CONCLUSION

Fast, extensive and simultaneous cartilage and bone degeneration developed shortly after haemarthrosis, as shown by the detailed mapping of the early pathogenesis of HA. The almost immediate loss of cartilage and the pathological bone turnover suggest a direct influence of blood on these processes and are unlikely to be attributed simply to an indirect effect of inflammation.

Genetic biomarkers related to hemarthrosis, inflammation, and cartilage structure in pediatric patients with hemophilic arthropathy

Background

The pathophysiology of hemophilic arthropathy is complex and not completely understood. In this study, we aimed to identify biomarkers that can affect the hemophilic arthropathy severity.

Methods

Fifty patients were analyzed for biomarker frequencies; in 37 patients, articular symptoms were evaluated based on the physical joint examination score, and in 18, it was based on magnetic resonance imaging. Eight polymorphisms, namely FV 1691G>A, FII 20210G>A, MTHFR 677C>T and 1298A>C, TNFα‐308G>A and ‐238G>A, ACAN VNTR, and IL1RN*2‐VNTR were identified.

Results

Patients with the MTHFR 677TT genotype showed a higher number of affected joints (1.83 ± 0.9 vs. 0.55 ± 0.7 for CC; p = .023), whereas those with the MTHFR 1298AC genotype exhibited higher effusion according to two radiologists (0.90 ± 0.31/1.20 ± 0.63 vs. 0.38 ± 0.52/0.50 ± 0.53 for AA genotype; p = .043/0.036, respectively). In addition, patients with the TNFα‐308GA genotype had more subchondral cysts (0.75 ± 0.95 vs. 0.07 ± 0.26 for GG genotype; p = .041).

Conclusions

The distribution of risk genotypes for MTHFR and TNFα‐308GA suggests their association with clinical parameters of hemophilic arthropathy. Cohort studies are essential to verify these associations.

TNF-α/TNF-R System May Represent a Crucial Mediator of Proliferative Synovitis in Hemophilia A

Hemophilic arthropathy (HA) typically begins with proliferative synovitis that shares some similarities with inflammatory arthritides, in which the proinflammatory cytokine tumor necrosis factor (TNF)-α has a crucial pathogenetic role. Inappropriate release of TNF-α was shown to contribute to arthropathy development following intra-articular bleeding in hemophilic mice. Here, we were interested in determining whether systemic levels of TNF-α and synovial tissue expression of the TNF-α/TNF receptor (TNF-R) system could be increased and related to joint damage in hemophilia A patients with severe HA. Serum levels of TNF-α measured by quantitative enzyme-linked immunosorbent assay (ELISA) were significantly increased in HA patients (n = 67) compared to healthy controls (n = 20). In HA patients, elevated TNF-α levels were significantly associated with the number of hemarthroses, the grade of synovial hypertrophy, and both the clinical World Federation of Hemophilia score and ultrasound score. The expression of TNF-α, TNF-R1, and TNF-R2 was strongly increased in HA synovium (n = 10) compared to the non-inflamed osteoarthritis control synovium (n = 8), as assessed by both immunohistochemistry and Western blotting. Increased protein levels of TNF-α, TNF-R1, and TNF-R2 were retained in vitro by HA fibroblast-like synoviocytes (n = 6) with respect to osteoarthritis control fibroblast-like synoviocytes (n = 6). Stimulation with TNF-α resulted in a significant increase in HA fibroblast-like synoviocyte proliferation quantified by the water-soluble tetrazolium (WST)-1 assay, while it had no relevant effect on osteoarthritis fibroblast-like synoviocytes. Quantification of active/cleaved caspase-3 by ELISA demonstrated that TNF-α did not induce apoptosis either in HA or in osteoarthritis fibroblast-like synoviocytes. The TNF-α/TNF-R system may represent a crucial mediator of proliferative synovitis and, therefore, a new attractive target for the prevention and treatment of joint damage in HA patients. Our findings provide the groundwork for further clinical investigation of anti-TNF-α therapeutic feasibility in hemophiliacs.

The role of orthopaedic surgery in haemophilia: current rationale, indications and results

The musculoskeletal problems of haemophilic patients begin in infancy when minor injuries lead to haemarthroses and haematomas.

Early continuous haematological primary prophylaxis by means of the intravenous infusion of the deficient coagulation factor (ideally from cradle to grave) is of paramount importance because the immature skeleton is very sensitive to the complications of haemophilia: severe structural deficiencies may develop quickly.

If primary haematological prophylaxis is not feasible due to expense or lack of venous access, joint bleeding will occur. Then, the orthopaedic surgeon must aggressively treat haemarthrosis (joint aspiration under factor coverage) to prevent progression to synovitis (that will require early radiosynovectomy or arthroscopic synovectomy), recurrent joint bleeds, and ultimately end-stage osteoarthritis (haemophilic arthropathy).

Between the second and fourth decades, many haemophilic patients develop articular destruction. At this stage the main possible treatments include arthroscopic joint debridement (knee, ankle), articular fusion (ankle) and total joint arthroplasty (knee, hip, ankle, elbow).

Cite this article: EFORT Open Rev 2019;4:165-173. DOI: 10.1302/2058-5241.4.180090

Timely and large dose of clotting factor IX provides better joint wound healing after hemarthrosis in hemophilia B mice

Bleeding into the joints represents the major morbidity of severe hemophilia and predisposes it to hemophilic arthropathy (HA). In a reproducible hemarthrosis mouse model, we found distinct changes in thrombin activity in joint tissue homogenate following exposure of the joint to blood in wide type (WT) and hemophilic B mice. Specifically, at early time points (4 h and 24 h) after hemarthrosis, thrombin activity in WT mice quickly peaked at 4 h, and returned to baseline after 1 week. In hemophilia B mice, there was no/minimal thrombin activity in joint tissues at 4 h and 24 h, whereas at 72 h and thereafter, thrombin activity kept rising, and persisted at a higher level. Nevertheless, prothrombin had not decreased in both WT and hemophilia. The pattern was also confirmed by Western blotting and immunostaining. To optimize the protection against development of HA, we tested different treatment regimens by administration of clotting factor IX into hemophilia B mouse after hemarthrosis induction, including a total of 600 IU/kg FIX within the first 24 h or the whole 2-week period. We concluded that timely (in the first 24 h) and sufficient hemostasis correction is critical for a better protection against the development of hemophilic arthropathy.

Bleed volume of experimental knee haemarthrosis correlates with the subsequent degree of haemophilic arthropathy

BACKGROUND

Haemophilic arthropathy is the main morbidity of haemophilia. The individual pathological response to the same number of clinically evident joint bleeds is highly variable; thus, it remains unknown if certain joint bleeding characteristics are critical for the development of arthropathy.

AIM

To study the relation between bleed volume and subsequent development of arthropathy, we aimed to develop quantitative in vivo imaging of active joint bleeds in a mouse model of haemophilia.

METHODS

Haemophilia A (F8-KO) and wild-type (WT) mice were IV-dosed with a micro-CT blood pool contrast agent prior to an induced knee haemarthrosis or sham procedure. The mice were micro-CT scanned five times the following 2 days to characterise and quantify the induced haemarthrosis in vivo. On Day 14, the mice were euthanized and pathological changes evaluated by histology and micro-CT. Additionally, bleeding characteristics in vehicle-treated F8-KO mice were compared with those of recombinant FVIII (rFVIII)-treated F8-KO mice.

RESULTS

F8-KO mice had a significantly larger bleed volume than WT mice at all scan time points. The bleed volume 12 hours after induction of haemarthrosis correlated with the subsequent degree of arthropathy. Presence of µCT-detectable bone pathology was associated with a significantly increased bleed volume among F8-KO mice. rFVIII treatment significantly reduced bleed volume in F8-KO mice.

CONCLUSION

Quantitative in vivo contrast-enhanced micro-CT imaging can be used to characterize and quantify joint bleeds in a mouse model of haemophilic arthropathy. The bleed volume correlates with the subsequent degree of arthropathy.

Comparison of 90-Day Complication Rates and Cost Between Single and Multiple Joint Procedures for End-Stage Arthropathy in Patients with Hemophilia

Background

Multiple joint procedures during a single anesthetic episode have been proposed for patients with hemophilia as a way to reduce cost. The postoperative 90-day complication rate and the cost distribution between multiple joint procedures and single joint procedures for patients with hemophilia have not been well studied.

Methods

Between January 1996 and December 2016, 124 patients underwent 177 surgical procedures (total knee arthroplasty, total hip arthroplasty, and ankle arthrodesis) for the treatment of hemophilic end-stage arthropathy. Forty-eight patients (39%) underwent multiple joint procedures during 1 hospitalization, and 76 patients (61%) underwent single joint procedures. The medical records were retrospectively reviewed. The patients were evaluated for complications within 90 days postoperatively and the cost during hospitalization. Risk factors related to complications were further analyzed.

Results

Twenty-seven of the 124 patients experienced 29 complications within 90 days postoperatively, representing a complication rate of 16.4% for all procedures. The patients who had undergone multiple joint procedures had a higher rate of surgical complications than those who had undergone a single joint procedure (14.6% vs. 3.9%; p = 0.039). The patients who had had multiple joint procedures had similar rates of hematological complications (8.3% vs. 9.2%; p = 0.867) and total complications (31.3% vs. 18.4%; p = 0.100) compared with those who had had a single joint procedure. There was no difference between the patients who had had multiple joint procedures and those who had had a single joint procedure with regard to the cost of the coagulation factor (p = 0.212).

Conclusions

The performance of multiple joint procedures during a single anesthetic episode is a safe approach for patients with hemophilia with end-stage arthropathy, with no substantial increase in the 90-day complication rate in comparison with that following a single joint procedure. The performance of multiple joint procedures under a single anesthetic episode can save cost and is more cost-effective when managing patients with hemophilia who have end-stage arthropathy.

Level of Evidence

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

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.

Programmed Sports Therapy (PST) in People with Haemophilia (PwH) "Sports Therapy Model for Rare Diseases"

Sports and exercise therapy becomes more and more integrated in the treatment plan of different diseases. Although the benefits of this therapy are of high quality evidence, e.g. in cardiovascular diseases, no concepts of sports therapy are available as a treatment option for rare diseases.

During the last eighteen years, we analyzed the situation as well as necessity, and developed a model, contents and the concept of the “Programmed Sports Therapy (PST)” for the treatment of PwH (people with haemophilia) as our model of rare disease. Many studies have shown that motoric skills are depressed in PwH, and that this gap to healthy people increases during age. The only way to reduce this progression is an appropriate therapy, adapted to the necessities of PwH. In haemophilia, in particular, physio- and sports therapy treatments should go hand in hand, the first in the acute phase after bleeding, the second later, after the acute phase has finished. One model, which considers all the different challenges, can be the cogwheel model presented here. Since haemophilia is a rare disease, new training concepts are necessary because classical group therapies are often impossible. PST based on the combination of sports therapy camps together with a supervised autonomous home training helps to directly bring the training to the trainee, in order to enhance key competences and improve the individual situation in PwH, and perhaps in patients with other rare diseases.

The experience and scientific data substantiate the success of “Programmed Sports Therapy (PST)” and even this can be a model for other rare diseases.

Modern Treatments of Haemophilia: Review of Cost-Effectiveness Analyses and Future Directions

BACKGROUND

Cost is currently one of the most important aspects in haemophilia care. Factor concentrates absorb more than 90% of healthcare direct costs of haemophilia care, and the debate regarding the high cost of haemophilia treatments and their different use across different countries is increasing.

OBJECTIVE

The objective of this study was to review cost-effectiveness analyses conducted on treatment options in haemophilia, focusing on their results and their strengths and limitations; to highlight the possible issues associated with economic evaluations of new treatment options.

METHODS

Electronic searches in PubMed and EMBASE were performed to retrieve papers published between November 2015 and September 2017 to update the previous review of economic evaluations of haemophilia treatments by Drummond et al. Reference lists of included articles and reviews were examined for relevant studies, which were assessed for their quality and their empirical results.

RESULTS

Twenty-six relevant economic analyses were identified; 15 (57.7%) were conducted in patients with haemophilia with inhibitors while 11 (42.3%) involved patients without inhibitors. There were methodological variations among the included studies, and differences in the treatment schemes make a comparative assessment of interventions for patients with haemophilia difficult. Only immune tolerance induction showed consistent results in its cost-saving profile compared with the treatment with bypassing agents.

CONCLUSIONS

Economic evaluations of haemophilia treatments are increasing, but the identification of general cost-effectiveness trends is still difficult in these studies. We are now facing a new era in haemophilia management with a soaring need for high-quality economic evaluations, performed through proactive collaboration between clinical experts, budget holders and health economists.

Subchondral haematoma

Haemophilic arthropathy is a complex multifactorial disorder that poses significant challenges to both the treating haematologist and arthroplasty surgeon. Its pathogenesis is incompletely understood. Recent literature has concentrated on the toxic effects of iron and the characteristic inflammatory synovitis. Discussion of the role of subchondral bleeding in joint damage has been neglected. A case of haemophilic arthropathy with extensive evidence of subchondral bleeding and related osteochondral destruction is presented.

RESULT

The relevance of this mechanical pathway in the future management of haemophilic arthropathy is discussed with reference to recent literature.

CONCLUSION

Clinicians should consider its importance when deciding whether to manage patients expectantly or with prophylactic factor replacement.

Components in Plasma-Derived Factor VIII, But Not in Recombinant Factor VIII Downregulate Anti-Inflammatory Surface Marker CD163 in Human Macrophages through Release of CXCL4 (Platelet Factor 4)

BACKGROUND

Hemarthrosis, or bleeding into the joints, is a hallmark of hemophilia. Heme triggers oxidative stress, inflammation, and destruction of cartilage and bone. The haptoglobin-CD163-heme oxygenase-1 (HO-1) pathway circumvents heme toxicity through enzymatic degradation of heme and transcription of antioxidant genes. Plasma-derived factor concentrates contain many proteins that might impact on cellular pathways in joints, blood, and vessels.

METHODS

Activation of platelets from healthy volunteers was assessed by flow cytometry analysis of fibrinogen binding and CD62P expression. Platelet CXCL4 release was measured by ELISA. Human peripheral blood mononuclear cells were exposed to CXCL4 or platelet supernatants (untreated or pre-stimulated with factor VIII (FVIII) products) during their differentiation to macrophages and analyzed for CD163 expression. Some macrophage cultures were additionally incubated with autologous hemoglobin for 18 h for analysis of HO-1 expression.

RESULTS

Platelet CXCL4 release was increased by all 8 tested plasma-derived FVIII products but not the 3 recombinant products. Macrophages exposed to supernatant from platelets treated with some plasma-derived FVIII products downregulated CD163 surface expression and failed to upregulate the athero- and joint protective enzyme HO-1 in response to hemoglobin.

CONCLUSION

Plasma-derived FVIII products might promote bleeding-induced joint injury via generation of macrophages that are unable to counteract redox stress.

Oligoarticular Hemarthroses and Osteomyelitis Complicating Pasteurella Meningitis in an Infant

A 5-month-old previously healthy female presented with a one-week history of fever and increased fussiness. Her presentation revealed an ill-appearing infant with an exam and cerebrospinal fluid (CSF) studies concerning bacterial meningitis; CSF cultures grew Pasteurella multocida. Additionally, brain magnetic resonance imaging (MRI) demonstrated cervical osteomyelitis. Despite multiple days of antibiotic therapy, she remained febrile with continued pain; MRI showed oligoarticular effusions, and aspiration of these joints yielded bloody aspirates. Evaluations for coagulopathy and immune complex-mediated arthropathy were negative. The patient improved following appropriate antibiotic therapy and spontaneous resolution of hemarthroses, and was discharged to a short-term rehabilitation hospital. P. multocida is a small, encapsulated coccobacillus that is part of the commensal oral flora of animals. It most commonly causes skin infections in humans, yet is a rare cause of meningitis in the pediatric population, especially in children <1 year of age. Transmission due to P. multocida is most commonly due to direct contact with animals. To our knowledge, this is the first case of oligoarticular hemarthroses and cervical osteomyelitis complicating P multocida meningitis. This case highlights the physician’s potential for cognitive bias and premature anchoring, and the resulting implications in delivering excellent patient care.

Ultrasound for Early Detection of Joint Disease in Patients with Hemophilic Arthropathy

Joint bleeding represents the most commonly reported type of hemorrhage in patients affected by hemophilia. Although the widespread use of prophylaxis has been able to significantly reduce the onset of arthropathy, it has been shown that a non-negligible percentage of patients develop degenerative changes in their joints despite this type of treatment. Thus, periodic monitoring of the joint status in hemophilia patients has been recommended to identify early arthropathic changes and prevent the development or progression of hemophilic arthropathy. Ultrasound (US) has proven able to detect and quantify the most relevant biomarkers of disease activity (i.e., joint effusion and synovial hypertrophy) and degenerative damages (i.e., osteo-chondral changes) by means of scoring scales of increasing disease severity. In the present review, we have detailed major literature evidence about the use of US to assess joint status in hemophilia patients, focusing on signs of disease activity and degenerative damages. In particular, we have discussed recent evidence about "point-of-care" use patients with hemophilia.

Treatment and Prevention of Bleeds in Haemophilia Patients with Inhibitors to Factor VIII/IX

The development of alloantibodies neutralising therapeutically administered factor (F) VIII/IX (inhibitors) is currently the most severe complication of the treatment of haemophilia. When persistent and at a high titre, inhibitors preclude the standard replacement treatment with FVIII/FIX concentrates, making patients’ management challenging. Indeed, the efficacy of bypassing agents, i.e., activated prothrombin complex concentrates (aPCC) and recombinant activated factor VII (rFVIIa), needed to overcome the haemostatic interference of the inhibitor, is not comparable to that of factor concentrates. In addition, the therapeutical response is unpredictable, with a relevant inter-individual and even intra-individual variability, and no laboratory assay is validated to monitor the efficacy and safety of the treatment. As a result, inhibitor patients have a worse joint status and quality of life compared to inhibitor-free subjects and the eradication of the inhibitor by immune tolerance induction is the preeminent therapeutic goal, particularly in children. However, over the last decades, treatment with bypassing agents has been optimised, allowing home treatment and the individualisation of regimens aimed at improving clinical outcomes. In this respect, a growing body of evidence supports the efficacy of prophylaxis with both bypassing agents in reducing bleeding rates and improving the quality of life, although the impact on long-term outcomes (in particular on preventing/reducing joint deterioration) is still unknown. This review offers an update on the current knowledge and practice of the use of bypassing agents in haemophiliacs with inhibitors, as well as on debated issues and unmet needs in this challenging setting.

Insights into cryotherapy and joint bleeding: cryotherapy and hemophilia

: There is some controversy over the use of cryotherapy. Low temperatures (Temp) could interfere with coagulation and increase the risk of bleeding. We sought to examine the effect of cryotherapy on joint swelling, temperature, friction, and inflammatory condition after experimental hemarthrosis. The left knee of 23 albino rabbits, 10 in heparin Ice, five in citrate Ice, four in heparin control, and four in citrate control were injected intraarticularly with 1 ml of blood. In total, four animals were considered to be in normal control group. Joint diameter, Temp, and ultrasonography were assessed before the blood injection. One day after the intraarticular blood injection, cryotherapy was applied 4 times per day for 4 consecutive days. Joint diameter and Temp were measured twice a day. After cessation of the protocol, joint diameter and Temp were assessed and sonography performed, animals euthanized, the friction test was performed and the synovial membrane collected, respectively. Joint diameter and Temp were increased after the intraarticular blood injection. Cryotherapy was capable of reducing the swelling and Temp. Ultrasonography findings approved the positive effect of cryotherapy on joint swelling. The proinflammatory tumor necrosis factor (TNF-α) reduced by cryotherapy in both cryotherapy groups but Interleukin 1β was only reduced in heparin group. Interleukin-4 increased in heparin Ice group that was in comparison with TNF-α reduction. Cryotherapy reduced joint swelling and has a positive effect on controlling joint inflammation and Temp.

A preliminary case series evaluating the safety and immediate to short-term clinical benefits of joint mobilization in hemophilic arthritis of the lower limb

OBJECTIVES

Arthritis resulting from recurrent intra-articular bleeding in individuals with hemophilia can be severely debilitating due to joint pain and stiffness with subsequent loss of mobility and function. Very limited studies have investigated the potential benefits of joint mobilization for this condition. This case series is a preliminary investigation of safety, as well as immediate and short-term clinical benefits, associated with gentle knee and ankle joint mobilization in people with hemophilic arthropathy.

METHODS

A single intervention of joint mobilization was applied to the affected knees and/or ankles of 16 individuals with severe or moderate hemophilia within a public hospital setting. Adverse events, as well as immediate (pain-free passive joint range, Timed Up and Go Test with maximum pain numerical rating scale) and short-term (Lower Extremity Functional Scale) effects of the intervention were evaluated with a repeated measures ANOVA.

RESULTS

There were no adverse events. An immediate significant increase was observed in pain-free passive ankle joint range of motion (p < 0.05) following the joint mobilization intervention.

DISCUSSION

The findings of this case series suggest that gentle joint mobilization techniques may be safely considered as part of a multimodal management approach for hemophilic arthropathy.

MicroRNA-15b Modulates Molecular Mediators of Blood Induced Arthropathy in Hemophilia Mice

The development of arthropathy is a major co-morbidity in patients with hemophilia. The present study was designed to study the role of a microRNA biomarker (miR-15b) in the development of joint disease. To investigate the expression profile of miR-15b during the development of arthropathy, we first isolated and studied small RNA from the acute and chronic hemarthrosis model of hemophilia A mice. We observed that miR-15b was consistently repressed (~1- to 4-fold) from the onset of joint bleeding (1, 3, 7 and 24 h) until six bleeding episodes (up to 90 days). To test if reconstitution of miR-15b modulates biomarkers of joint damage in a chronic hemarthrosis model, we administered an adeno-associated virus (AAV) 5-miR-15b vector intra-articularly alone or in combination with systemic administration of AAV2-factor VIII. miR-15b overexpression downregulated markers of angiogenesis and hypoxia (vascular epithelial growth factor α (VEGF-α) and hypoxia inducing factor 2α (HIF-2α), ~70% and ~34%, respectively) in the affected joints. In addition, the co-administration of miR-15b and factor VIII vectors reduced the levels of the chondrodegenerative matrix-metalloproteinases (MMPs) 1, 3, 9 and 14 (~14% to 60%) in the injured joints. These data demonstrate for the first time the role of a miR-15b in the development of hemophilic arthropathy and has implications in development of miR based therapies for joint disease.

Advances and challenges in hemophilic arthropathy

Hemophilic arthropathy is a form of joint disease that develops secondary to joint bleeding and presents with synovial hypertrophy, cartilage and bony destruction. The arthropathy can develop despite clotting factor replacement and is especially disabling in the aging population. Pathobiological tissue changes are triggered by release of hemoglobin and iron deposition in the joint, but the sequence of events and the molecular mechanisms resulting in joint deterioration are incompletely understood. Treatment options other than clotting factor replacement are limited. Improvements in the treatment of hemophilia necessitate a better understanding of the processes that lead to this disabling condition and better diagnostic tools. Towards that end, studies of the molecular mechanisms leading to the arthropathy, as well as the development of sensitive imaging techniques and biomarkers are needed. These will pave the way to identify the cause of acute pain such as joint bleeding or synovitis, detect early, potentially reversible structural changes, and predict progression of disease. This review describes current imaging techniques and the development of high resolution musculoskeletal ultrasound with power Doppler to afford point-of-care diagnosis and management, the potential utility of diagnostic biomarkers, and summarizes our current knowledge of the pathobiology of hemophilic arthropathy.

Joint bleeds in von Willebrand disease patients have significant impact on quality of life and joint integrity: a cross-sectional study

BACKGROUND

Joint bleeds (JB) are reported in a minority of patients with von Willebrand disease (VWD) but may lead to structural joint damage. Prevalence, severity and impact of JB in VWD are largely unknown.

OBJECTIVES

The aim of this study was to assess JB prevalence, onset, treatment and impact on health-related quality of life (HR-QoL) and joint integrity in moderate and severe VWD.

METHODS

In the Willebrand in the Netherlands study 804 moderate and severe VWD patients [von Willebrand factor (VWF) activity ≤30U dL(-1)] completed a questionnaire on occurrence, sites and consequences of JB. To analyse JB number, onset, treatment and impact on joint integrity we additionally performed a patient-control study on medical file data comparing patients with JB to age, gender, factor VIII (FVIII)- and VWF activity matched VWD patients without JB.

RESULTS

Of all VWD patients 23% (184/804) self-reported JB. These 184 patients reported joint damage more often (54% vs. 18%, P < 0.001) and had lower HR-QoL (SF36, P < 0.05) compared to VWD patients not reporting JB. Of 55 patients with available JB data, 65% had the first JB before age 16. These 55 patients used more clotting factor concentrate (CFC; median dose 43 vs. 0 IE FVIII kg(-1) year(-1) , P < 0.001), more often had X-ray joint damage (44% vs. 11%, P = 0.001] and chronic joint pain (44% vs. 18%, P = 0.008) compared to 55 control VWD patients without JB.

CONCLUSION

In conclusion, joint bleeds are reported by 23% of moderate and severe VWD patients, mostly start in childhood, are associated with more CFC use, joint pain, lower HR-QoL and significantly more radiological and self-reported joint damage.

The role of physical medicine and rehabilitation in haemophiliac patients

Physical medicine and rehabilitation aim to evaluate, diagnose and treat disability in haemophiliac patients, while preventing injury or deterioration. They also aim to maintain the greatest degree of functional capacity and independence in patients with haemophilia, or to return them to that state. Rehabilitation, together with clotting factor replacement therapy, has revolutionized the management of these patients in developed countries and reduced their morbidity/mortality rates. A knowledge of the musculoskeletal signs and symptoms of haemophilia is essential for providing a treatment which is suitable and customized. Physical medicine and rehabilitation techniques, which are based on physical means, are intended to reduce the impact which these injuries and their consequences or sequelae can have on the quality of life of patients with haemophilia. Under ideal haemostatic control conditions (primary prophylaxis), people with haemophilia could achieve good physical condition which will allow them to enjoy both physical activity and a daily life without limitations. Currently, children undergoing primary prophylaxis are quite close to this ideal situation. For these physical activities to be carried out, the safest possible situations must be sought.

Rapid musculoskeletal ultrasound for painful episodes in adult haemophilia patients

Little objective information exists about musculoskeletal bleeding patterns in haemophilic arthropathy. Bleeding is assumed to be the cause of painful joints or muscles. Clotting factor treatment is provided empirically, but often does not alleviate pain. We hypothesized that perception of pain aetiology is unreliable, and introduced point-of-care high-resolution musculoskeletal ultrasound (MSKUS) to differentiate intra-articular bleeds vs. joint inflammation, and intra-muscle bleeds vs. other regional pain syndromes. To assess painful musculoskeletal episodes in adult haemophiliacs, we used rapid MSKUS, employing grey scale and power Doppler examination. Forty episodes in 30 adult haemophiliacs were evaluated. Thirty three of the 40 episodes were patient-reported as 'bleeding', five as 'arthritis-type' pain and two as 'undecided'. Of the 33 bleeding reports, only 12 were confirmed by MSKUS; the other episodes revealed other pathology. In contrast, three of five perceived arthritis flares were reclassified as bleeds. Similarly, physician assessment was incorrect in 18 of 40 instances. Swelling and warmth were present in approximately half of confirmed bleeding and non-bleeding episodes, and therefore not useful clinically. Few of the painful episodes were symptom controlled at the time of MSKUS. Management changed based on objective imaging findings in >70% of episodes, which resulted in symptom improvement >60% of the time. Significant discrepancies exist between MSKUS findings and patient/physician-perceived pain classification as bleeding or other musculoskeletal symptoms. Current practice of prescribing clotting factor or conservative measures based on pain perception seems inadequate and suggests that point-of-care imaging should be included into modern haemophilia care.

Prevalence of clinical hip abnormalities in haemophilia A and B: an analysis of the UDC database

Clinical hip abnormalities, secondary to recurrent joint and/or muscle bleeding in persons with haemophilia, have not been well characterized and have the potential for significant morbidity. We aimed to examine the prevalence of clinical hip abnormalities in the US haemophilia population and to explore associations between these findings and putative risk factors. We conducted a study of hip abnormalities of 8192 subjects aged 2-69 years with haemophilia A and haemophilia B (54% of haemophilia A and haemophilia B are severe) currently enrolled in the Universal Data Collection (UDC) database. Associations between hip abnormality and type/severity of haemophilia A/B, current age, history of high-titre (≥ 5 BU) inhibitor (HTinh), concomitant ankle (AA) and knee arthropathy (KA), overweight and obesity and prophylaxis were examined using logistic regression. Overall prevalence of hip abnormality at the last recorded UDC visit for all subjects was 16.7%. Haemophilia A (aOR = 1.3, 1.0-1.4), severe haemophilia (aOR = 1.3, 1.0-1.5), a history of HTinh (aOR = 1.4, 1.1-1.7), and concomitant AA (aOR = 1.7, 1.4-1.9) were each independently associated with hip abnormality. Older age (45-69 years) was significantly associated with hip abnormality prevalence only in subjects with KA (aOR = 3.4, 1.9-5.9). The presence of overweight (aOR = 1.4, 1.1-1.8) and obesity (aOR = 2.1, 1.6-2.8) was associated with hip abnormality only among subjects without KA. Hip abnormality prevalence was not influenced by prophylaxis (aOR = 0.9, 0.8-1.1). These data suggest that hip abnormalities in US patients with haemophilia are associated with haemophilia severity and type, HTinh, concomitant AA and, depending on the presence or absence of KA, advancing age and obesity.

Differing approaches to diagnosis and treatment of musculoskeletal complications of haemophilia in resource-rich and resource-limited settings

Management of the musculoskeletal complications of haemophilia should be consistent in both RRS (resource-rich settings) and RLS (resource-limited settings). Due to the lack of available resources in RLS, physicians face challenges that may limit their options for procedures. This article aimed to define the role of different techniques for the management of the musculoskeletal complications of haemophilia in RRS and RLS. A review of recent literature on the topic has been performed. In RLS, ultrasonography can be used as a diagnostic tool instead of MRI; chemical synovectomy can be the first alternative instead of radiosynovectomy and arthroscopic synovectomy; percutaneous treatment of pseudotumours can be performed instead of open surgical removal; finally, autologous cancellous bone can be used to fill cysts and pseudotumours instead of cancellous bone obtained from the Bone Bank. All diagnostic tools and treatments recommended for RLS have been proven to be efficacious; however, the ideal diagnosis and treatment for the musculoskeletal complications of haemophilia in RRS include MRI, radiosynovectomy, arthroscopic knee and ankle debridement in the early stages of arthropathy, total knee arthroplasty and total ankle arthroplasty or ankle fusion (in advanced stages of arthropathy), and surgical removal of pseudotumours. Treatments considered ideal in RRS should be the first therapeutic option if available. However, secondary treatment options that are less costly and therefore more readily available in RLS are perfectly valid and efficacious.

Prevention of the musculoskeletal complications of hemophilia

Hemophilia is an inherited disorder of clotting factor deficiencies resulting in musculoskeletal bleeding, including hemarthroses, leading to musculoskeletal complications. The articular problems of hemophiliac patients begin in infancy. These include: recurrent hemarthroses, chronic synovitis, flexion deformities, hypertrophy of the growth epiphyses, damage to the articular cartilage, and hemophilic arthropathy. The most commonly affected joints are the ankle, the knee, and the elbow. Hematologic prophylactic treatment from ages 2 to 18 years could avoid the development of hemophilic arthropathy if the concentration of the patient's deficient factor is prevented from falling below 1% of normal. Hemarthroses can be prevented by the administration of clotting factor concentrates (prophylaxis). However, high costs and the need for venous access devices in younger children continue to complicate recommendations for universal prophylaxis. Prevention of joint arthropathy needs to focus on prevention of hemarthroses through prophylaxis, identifying early joint disease through the optimal use of cost-effective imaging modalities and the validation of serological markers of joint arthropathy. Screening for effects on bone health and optimal management of pain to improve quality of life are, likewise, important issues. Major hemarthrosis and chronic hemophilic synovitis should be treated aggressively to prevent hemophilic arthropathy.