How does joint impairment affect the functional capacity of the lower limb in early haemophilia-related arthropathy?

The impact of joint damage on functional capacity in patients with mild haemophilia (PwMH) has yet to be well studied. The primary aim of this study was to investigate the effect of joint impairment on the functional capacity of the lower limb in PwMH. The secondary aim was to identify physical predictors of lower limb functional capacity.

Forty-nine PwMH were evaluated. Dynamic balance was assessed using Time Up and Go (TUG). Thirty-second sit-to-stand (30-STS) and 60-second-STS (60-STS) were used to assess muscle power and endurance, respectively. Haemophilia Early Arthropathy Detection with Ultrasound (HEAD-US) was used to assess joint damage. PwMH were divided based on HEAD-US: with joint damage (≥3 points) and without or with very low joint damage (0-2 points). Univariate ANOVA and multiple regression analyses were performed to identify differences in functional capacity and potential physical predictors.

Only 30-STS showed significant differences between groups (p = .002). TUG and 60-STS were primarily explained by age (r²  = .21 and r²  = .44, respectively), while for 30-STS, age combined with joint damage and pain level explains 54% of the variance.

Our findings indicate that the 30-STS is useful for assessing functional deterioration in people with early-stage haemophilia-related arthropathy. Our results also indicate that joint damage, combined with ageing and pain, may impact 30-STS outcomes in PwMH. Furthermore, our findings show that the loss in TUG and 60-STS performance in PwMH is related to ageing.