400 Section - Knee hypermobility, knee laxity, and pain are not related in females with Hypermobility Spectrum Disorders and hypermobile Ehlers-Danlos Syndrome

Objectives : Hypermobility Spectrum Disorders (HSD) and hypermobile Ehlers-Danlos Syndrome (hEDS) affect 1 in 500 people. These conditions are characterized by joint hypermobility and chronic pain, but correlations between joint hypermobility, joint laxity, and pain in HSD/hEDS have not been well-established. This study aimed to quantify associations between active knee hyperextension range (KE), passive knee joint laxity (KJL) and generalized pain in females with and without HSD/hEDS.

Design:

Females with and without HSD/hEDS participated during the follicular phase of their menstrual cycle. During a single testing session the Brief Pain Inventory, maximum KE, and maximum anterior-posterior KJL were assessed. Independent t-tests (parametric data) or Mann-Whitney U tests (non-parametric data) were performed for between-group differences. Correlations were determined using Pearson’s r and Kendal’s τ. Statistical significance was set at α=0.05.

Results: 12 females with HSD/hEDS (age 27±7 years) and 6 controls (age 29±8 years) participated. Average bodily pain over the last 24 hours (/10) was more severe in HSD/hEDS (3.8±2.0 vs. 0.5±0.6; p=0.001). Left KE was greater (10±4˚ vs. 6±2˚; p=0.04) but right KE was similar (10±4˚ vs. 7±2˚; p=0.09) between HSD/hEDS and controls. KJL was similar between HSD/hEDS and controls for both knees (right: 10.0±3.5mm vs. 10.0±2.0mm; p=0.82; left: 12.0±2.5mm vs. 11.0±2.0mm; p=0.35). Within each group, no associations were observed between pain, KJL or KE (p >0.05).

Conclusion:

In this investigation there was no relationship between active knee joint hypermobility (part of the Beighton Score diagnostic criteria for HSD/hEDS) and knee joint laxity in females with and without HSD/hEDS. In addition, the degree of KE and KJL were not associated with the degree of pain in either group. HSD/hEDS are very heterogenous conditions. As such, clinicians should likely consider the multisystemic effects of these conditions rather than solely the degree of joint hypermobility or joint laxity in understanding and managing an individual patient's pain.