Background. Hemophilia is characterized by the development of a progressive, degenerative, intra-articular lesion (hemophilic arthropathy). This arthropathy presents with chronic pain, limited range of motion, axial changes, and periarticular muscle atrophy. Goal. To analyze the clonic, functional and musculoskeletal differences between adult patients with hemophilic arthropathy of the knee and ankle and their healthy peers. Study design. Cases and controls study patients. 21 patients with hemophilia A and B and 21 subjects without joint damage. Variables and measuring instruments: pressure pain threshold (pressure algometer); joint status (Hemophilia Joint Health Score scale); and strength (dynamometry) and muscle activation (surface electromyography). Expected results. Observe the differences between patients with knee and ankle arthropathy and their healthy peers in muscle strength and activation.
Study Type
OBSERVATIONAL
Enrollment
42
The dependent variables (muscle strength, muscle activation, pressure pain threshold and joint status) and the outcome measures used to measure these variables will be: pressure dynamometer, surface electromyography, pressure algometer and Hemophilia Joint Health Score
Assess the muscle strength
The force will be measured with a pressure dynamometer (Lafayette Manual muscle Tester model 01165). This device measures in Newton the force exerted by the patient in the requested muscular action. The higher the value, the greater muscle strength. We will perform the measurements bilaterally. Strength in the quadriceps and triceps surae muscles will be measured. The patient will be asked for 2 maximum isometric contractions of 5 seconds, with a rest of 30 seconds between them. In all the measurements, the evaluator will encourage the patient in a standardized way to carry out the contractions. In the measurement of the strength of all the muscles evaluated, the mean value of the measurements obtained will be used as a measure.
Time frame: Screening visit
Assess the muscle activation
Muscle activation will be measured with surface electromyography (Shimmer Sensing model, Dublin, Ireland). Using this instrument, we will evaluate the electrical activity of the muscles and their level of activation. The placement of the electrodes will be marked on the subjects standing, and they will be placed following the European recommendations for the use of SEMG. A bipolar SEMG system will be used with circular electrodes 10 mm in diameter, 20 mm apart, placed longitudinally, in the direction of the muscle fibers studied, and with a reference electrode at a distance. The unit of measure is the μV. The higher the score, the greater muscle activation.
Time frame: Screening visit
Assess the pressure pain threshold
Pressure pain threshold will be measured with a pressure algometer (Wagner FPIXTM Digital Algometer model). This device measures in Newton/cm2 the pressure at which the subject perceives pressure pain. A pressure will be applied that we will increase at an approximate speed of 50kPa/s until the patient tells us that the sensation is beginning to be painful. In the knee we will measure bilaterally 3 cm medially to the midpoint of the inner edge of the patella, 2 cm proximally to the superior pole of the patella. At the ankle we will measure bilaterally ventrally to the lateral malleolus.
Time frame: Screening visit
Assess the joint status
In patients with hemophilia, joint status will be assessed with the Hemophilia Joint Health Score. This specific scale for use in patients with hemophilia is used to measure the joint status of patients with hemophilic arthropathy. It evaluates 8 items: inflammation and its duration, pain, muscle atrophy and strength, crackles, and loss of flexion and extension. It has a score of 0 (no joint damage) to 20 points (maximum joint damage) per joint (elbows, knees and ankles). A gait rating is added to 120 points (range 0-4 points), with the maximum rating on this scale being 124 points.
Time frame: Screening visit
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