Age Effect on Pressure Pain Threshold of Asymptomatic Ankles and Knees in Young Individuals with and without Hemophilia: A Cross-Sectional Study

Introduction Despite adequate medical treatment, many young adults with hemophilia develop joint alterations—especially in ankles and knees. Undetected over years, subtle structural changes cause subclinical symptoms, before problems become obvious. To objectify these silent periarticular pressure pains, also referred to as silent symptoms, the pressure pain threshold (PPT) can be measured by algometry.

Aim The aim of this study was to investigate and compare the age effect on PPTs in asymptomatic ankles and knees between boys and young adults with hemophilia and age-matched controls in order to gain better knowledge about the alteration of the periarticular structures with increasing age.

Materials and Methods Nineteen persons with hemophilia (PwH; severe or moderate; 8–30 years) and 19 age-matched controls with “healthy” ankles and knees were recruited. Asymptomatic joints with a Hemophilia Joint Health Score = 0 were included. The PPT was measured on four periarticular points per joint, and the data were analyzed with a linear mixed model.

Results The difference in age effect per year in kilopascal (kPa) between PwH and controls was: β [95% CI]: 15.41 [−31.63; 0.79]. Although not reaching statistically significance (p = 0.08), a clear tendency was shown. As illustrated in the left graph of [Fig. 1], the PPT (in kPa) of the control group presented a positive slope in the range between 8 and 29 years of age, whereas in the right graph, the PwH showed a negative slope over the same age span. Hence, with growing age, ankles, and knees of PwH are more sensitive to pressure, whereas the joints of the control group decrease in sensitivity. In both groups, the ankle showed a lower PPT than the knee.

Conclusion With growing age, the PPT of ankles and knees of PwH decreases even in asymptomatic joints. Simultaneously, the gap to the PPT of healthy controls increases. This suggests that subclinical alterations in the periarticular structures of these joints develop unnoticed over time.

Fig. 1 PPT in kPa of ankles and knees in dependency of age.

Horizontal axis: age of participants in years. Vertical axis: PPT in kPa; group C: control group; H: PwH.

Publication History

Article published online:
13 November 2020