MRI Role in Knee Hemophilic Arthopathy

Hemophilia is a mostly inherited genetic disorder caused by a complete or partial deficiency of coagulation factors VIII or IX, which impairs the body's ability to form blood clots-a process necessary to stop bleeding. This results in prolonged bleeding after injury, easy bruising, and an increased risk of internal bleeding, particularly within joints or the brain. Hemophilic arthropathy (HA), caused by recurrent hemarthrosis, is the most common musculoskeletal manifestation of hemophilia and one of the most disabling complications of the disease. It can lead to severe pain, deformity, destruction of the joint, debilitating arthritis, and permanent joint damage. Clinical assessment plays only a minor role in detecting the early stages of HA, as early clinical signs are often nonspecific and of limited value in quantifying disease involvement. Conventional radiographs mainly detect bone lesions that appear in advanced HA, but they cannot identify early changes such as synovial hypertrophy or focal cartilage destruction. Computed tomography (CT) is highly sensitive for detecting bone changes, but it provides limited information on soft tissue involvement and requires a relatively high dose of ionizing radiation. By contrast, magnetic resonance imaging (MRI) offers superior soft tissue contrast, allowing detailed evaluation of hemophilic joints and visualization of synovial and cartilaginous abnormalities. T1-weighted imaging: evaluates bone marrow, joint anatomy, and subchondral changes. T2 fat-suppressed imaging: useful for detecting synovitis and joint effusion. Gradient echo (GRE) or susceptibility-weighted imaging (SWI): detect chronic blood products (hemosiderin), with SWI being more sensitive and able to identify earlier blood deposits. Several scoring systems exist for the assessment of hemophilic arthropathy, including the European scoring system and the International Prophylaxis Study Group (IPSG) MRI scale. The IPSG system provides more detailed scoring and greater sensitivity for early disease, including subtle synovial changes. For radiographs, the most widely used system is the Pettersson radiographic scoring system. In this study, the investigators will use the IPSG MRI scoring system and the Pettersson X-ray scoring system to evaluate hemophilic arthropathy, with the aim of improving grading, management, and follow-up.