286. Level of Joint Hypermobility in Children not Associated with Degree of Pain or Restriction in Function

Abstract

Background: Children with non‐inflammatory musculoskeletal pain make up a large proportion of referrals to paediatric rheumatology clinics. Many have a degree of joint hypermobility (JHM) and the literature describes this group as being more likely to experience joint pain and restriction of daily activity than their peers. The direct association between degree of hypermobility and pain however has not been confirmed and the literature is conflicting. We studied a group of hypermobile children experiencing musculoskeletal pain, as part of randomized controlled trial of therapeutic intervention in Benign Joint Hypermobility syndrome (BJHS). Our aim was to determine whether there was any association between degree of hypermobility and level of reported pain and restriction of activity. Methods: We recruited children between the ages of 5‐16 years old from children referred to secondary care paediatric services at the Norfolk and Norwich University Hospital with musculoskeletal pain. Children who were deemed to be hypermobile by a paediatric rheumatologist were included in the study. Baseline assessments were conducted to determine level of hypermobility (Beighton and Bulbena scores); degree and site of child reported pain (Faces visual analogue scale); and parent‐observed pain score and function using the Childhood Health Assessment Questionnaire (CHAQ). Participants were questioned on school absence due to pain and weekly participation in sporting activity. Results: A sample of 120 children was recruited, 65 (54.2%) female, mean age 9.47 (S.D. 3.17). Pain was most commonly reported in the muscles of the legs (27.5%). The most commonly reported sites of arthralgia were the knees (23.3%), back (17.5%) and finger joints (14.2%). There was no correlation with either Beighton or Bulbena score and child's reported pain (r=0.0018 and ‐0.0436 respectively) and no correlation to parent reported pain level (r=0.053 and ‐0.06 respectively). No correlation was seen between the reporting of knee pain and the degree of hypermobility in the knees (r=‐ 0.0663) and between reporting back pain and lumbar spine hyperflexion (r=0.0082). There was no difference in degree of hypermobility according to gender but a statistically significant negative correlation between Bulbena score and increasing age (regression coefficient ‐0.515, P‐value 0.007). No association was seen between degree of hypermobility and either level of weekly sporting activity (Beighton score r=‐0.0033, Bulbena score r=0.0134) or the number of school absences (Beighton score r=0.0512, Bulbena score r=‐0.0752). Conclusion: These results show that in JHM, the degree of joint hypermobility is a poor predictor of a child's level of pain and their restriction in sporting and academic participation. Pain reporting is independent of physical characteristics and interventions may need to focus on other exacerbating factors rather than simply on the joints.