Description of the condition
Hemophilia is a congenital condition in which the absence or defect of a clotting protein affects the ability of the blood to form a stable clot. The two most common types are hemophlia A and hemophlia B. Hemophilia A is caused by a defect of clotting factor VIII, and hemophilia B (Christmas disease) is caused by a defect of factor IX.
According to the World Federation of Hemophilia (WFH), hemophilia has an expected frequency of approximately one per 10,000 births and there are approximately 400,000 people with hemophilia worldwide (WFH 2012). Hemophilia A is more common than hemophilia B, representing 80% to 85% of the total hemophilia population (WFH 2012). Hemophilia is caused by an inherited X-linked recessive trait. The severity of hemophilia is constant within families and throughout the lifespan of the affected individual.
The frequency and severity of bleeding in hemophilia is generally correlated with the clotting factor level. The severe form accounts for more than 50% of the cases and has factor levels less than 1% IU/mL. It is associated with so-called spontaneous bleeding or bleeding as a result of unknown or unrecognised trauma. The moderate form has factor levels between 1% IU/mL and 5% IU/mL and hemorrhage can follow minor trauma. The mild form has a factor level of more than 5% IU/mL, but less than 40% IU/mL, in which hemorrhage usually occurs only after major trauma or surgery (White 2001).
Males who have the defective X chromosome are affected, while females with the defective gene are carriers of the condition, having one normal and one abnormal X chromosome, and may show symptoms of mild or moderate hemophilia. Each daughter of a female carrier has a 50% chance of also being a carrier; all daughters of men with hemophilia will be carriers. Each son of a carrier female has a 50% chance of being affected; sons of males with hemophilia do not inherit the father’s X chromosome, and are therefore not affected. In approximately one third of new cases, there is no family history, and the condition arises due to a spontaneous genetic mutation in either the mother or the son.
Internal and prolonged bleeding are the main symptoms of hemophilia, and hemorrhagic episodes can occur anywhere in the body. For both hemophilia A and B, hemarthrosis (bleeding into a joint) is the most common site of bleeding and accounts for 70% to 80% of all bleeding episodes; this is followed by muscle bleeds which account for 10% to 20% of bleeding episodes (WFH 2012). Ankles, knees and elbows are the more frequently affected joints. Hips, shoulders, and the small joints of the hands and feet are less commonly affected (Branea 2005). Joint disease affects 90% of people with severe hemophilia and contributes the greatest cost and morbidity in the hemophilia population (Manco-Johnson 2004). Recurrent hemarthrosis and muscular bleedings have serious consequences on the musculoskeletal system and the functional health status of patients.
In an acute hemarthrosis, blood flows from the vessels of the synovial membrane and fills the joint cavity. A few hours after blood enters the joint, the joint capsule becomes distended and there is an acute inflammatory reaction. Clinically, an acute hemarthrosis is characterized by pain, effusion, loss of range of motion, muscle inhibition or weakness and loss of joint proprioception. Once the bleeding has stopped, acute hemarthrosis usually recovers in approximately one week as a result of the digestive action of the synoviocytes of the synovial membrane, which removes the blood. Repeated hemarthroses are common; in its attempts to clear all of the accumulated blood, the synovium becomes hypertrophied, inflamed, villous and highly vascularized (De La Corte-Rodriquez 2013). This begins the vicious cycle of acute hemarthrosis and synovitis, which eventually leads to chronic synvovitis and the destruction of the joint cartilage. Damage to the joint cartilage occurs directly as a result of apoptosis of the chondrocyte cell and indirectly due to destructive enzymes and cytokines that are released from inflammatory cells in the synovial membrane (Rodriquez-Merchan 2012; Roosendaal 2008). In vitro animal studies have shown that the effect of blood on cartilage is accentuated by several factors including the duration of exposure to blood, weight bearing while there is blood in the joint and age; younger cartilage is more susceptible to damage than older cartilage (Roosendaal 2008). Chronic hemophilic arthropathy radiographically presents as synovial thickening, epiphyseal overgrowth, periarticular osteopenia, narrowed joint space, subchondral cysts, and incongruence of the joint surfaces (Pettersson 1980).
Description of the intervention
For the purpose of this review, exercise will encompass "a diverse set of interventions prescribed or planned by a health professional that includes conducting specific activities, postures or movements". Examples of such interventions are general physical fitness, aerobic exercise, strengthening of specific muscles or group of muscles, and various types of flexibility and stretching exercises (Blamey 2010).
How the intervention might work
Exercise programs for people with hemophilia are usually designed and implemented to help manage the recovery after a hemarthrosis or a muscle bleed, or as a tool to help prevent frequent bleeding episodes.
The aims of exercise that are considered to be important for people with hemophilia are to:
promote normal neuromuscular development (WFH 2012);
preserve or restore range of motion (ROM) and flexibility around joints;
increase muscular strength and endurance;
maintain or improve co-ordination and balance (WFH 2012);
maintain a healthy body weight thus decreasing stress on joints;
promote development and maintenance of good bone density (WFH 2012);
improve aerobic conditioning;
Healthier joints will allow individuals with hemophilia to function in their community. Regular physical activity benefits communities by lowering healthcare costs and improving productivity at work and school. A significant proportion of healthcare expenditure and gross domestic product (GDP) is attributed to costs related to the lack of physical activity and obesity. Promoting physical activity can be a highly cost-effective and a sustainable public health intervention (Riske 2007).
The World Health Organization (WHO) and the US Centers for Disease Control and Prevention have produced numerous reports and publications in which scientific evidence demonstrates that regular and appropriate physical activity and sports provides people of all ages and conditions (including disabilities), with a wide range of physical, social and mental health benefits (Benifits Centre for Disease Control 2007).
Why it is important to do this review
Over the past 40 years, the medical treatment for people with hemophilia has evolved from transfusions of whole blood to the use of fractionated blood products and to the use of recombinant technology. The availability and safety of coagulation factor products has allowed a philosophical change in medical care that previously limited activities and exercise for people with hemophilia because of concerns about the induction of bleeding (Riske 2007).
The threats to a healthy musculoskeletal system for people with hemophilia encompass every element of joint and muscle function. Decisions regarding what type of activity to undertake to minimize joint and muscle bleeding, and how to maintain or maximize the structure and function of both the bony and soft tissue elements, require expert physiotherapy care by a professional trained in the management of inherited bleeding disorders. Since therapeutic exercise is an important component of the management of other forms of arthropathy (e.g. osteoarthritis, rheumatoid arthritis), it would appear logical that exercise would be effective for people with hemophilia (Hunter 2009; Stenstrom 2003).
Thus, this review will seek to evaluate the use, safety and efficacy of exercise in preventing bleeding episodes, maintaining and restoring joint and muscle function, and in maintaining the ability of the individual with hemophilia to participate in society.