Joint-health Outcome Scoring: Exploration in Patients With Hemophilia in Austria (JOSEPHA Phase 1)

Hemophilia is an inherited disease caused by deficiency in varying degrees of clotting factors VIII and IX. Depending on the percentage of clotting factor in the blood the disease is categorized as "severe" (<1%, characterized by spontaneous bleedings), "moderate" (1-5%) and "mild" (>5%). If untreated, recurrent bleeding into the synovial joints often results in irreversible damage due to destruction of the cartilages and progressive joint impairment.

3d-gait analysis has been demonstrated as valid method to assess abnormal gait patterns and to monitor disease progression in patients with hemophilia (PWH). Furthermore, its outcomes facilitate the design of individually tailored therapeutic programs. In contrast to radiological examinations, 3d-gait analyses take place under weight-bearing conditions, which is a relevant issue in terms of weight-induced pain.

This study aims to explore the applicability of 3-d gait analysis as biomarker (gait deviation index) for functional impairments in PWH. Besides 3-d gait scores, secondary endpoints such as biomarkers reflecting cartilage damage and a laterality-ratio of leg muscle mass (in the case of one-sided target joints) will be tested for their ability to detect functional impairments in young adults with hemophilia.

Based on sample size calculation, 24 subjects aged 16-49 years, able to walk without aids or assistance will be included in each of the two groups: control (healthy, male), PWH (severe or moderate, treated prophylactically). Subjects suffering from functional impairments caused by other conditions than hemophilia, patients with bleedings within 30 days prior to the examination, PWH treated with immune-tolerance therapy and/or not successfully treated present or past high-titer factor VIII or FIX inhibitor will be excluded.

Subjects will pass through a set of examinations (medical history, clinical examination, 3d-gait analysis, anthropometrics, body composition analysis, venipuncture, and urine sampling) and carry an accelerometer device for seven consecutive days.

Confounder adjusted group differences will be assessed by ANCOVA with contrasts and Bonferroni correction. Correlations between the applied examination approaches will be assessed.

An evidence based health promotion program including follow-up examinations, physical activity promotion, and tailored physiotherapy are being envisaged as a follow-up project (JOSEPHA phase 2).