Knee function in 10-year-old children and adults with Generalised Joint Hypermobility

Abstract Purpose Knee function is reduced in patients with Benign Joint Hypermobility Syndrome. The aim was to study knee function in children and adults with Generalised Joint Hypermobility (GJH) and Non-GJH (NGJH)). Materials and methods In a matched comparative study, 39 children and 36 adults (mean age children 10.2 years; adults 40.3 years) were included, comprising 19 children and 18 adults with GJH (Beighton ≥ 5/9; Beighton ≥ 4/9), minimum one hypermobile knee, no knee pain (children), and 20 children and 18 adults with NGJH (Beighton < 5; Beighton < 4). Totally, 85% of the adults were parents to these children. Knee function was determined by self-reported physical fitness (100 mm VAS), Knee injury and Osteoarthritis Outcome Score (KOOS) (only adults), measured maximum isokinetic knee strength (60°/s) and peak vertical jump displacement (PVJD), with calculated knee strength balance, Hamstring/Quadriceps (H/Q) ratio and peak rate of force development (PRFD). Results Adults with GJH had lower knee function (KOOS: pain, p = 0.001; symptoms, p = 0.001; Activities of Daily Living, p = 0.001; Sport/Recreation, p = 0.003; knee-related quality of life, p < 0.001), and H/Q ratio (0.46 vs. 0.54, p = 0.046) than adults with NGJH, regardless of age and knee pain. Both GJH groups had normal physical fitness, isokinetic knee strength, and (only children) H/Q ratio. Conclusions Children at 10 years with GJH have normal, but adults with GJH have impaired knee function. To track the risk of developing impaired knee function, children with GJH must be followed longitudinally. Meanwhile, attention to knee function may be given to children with GJH who have parents presenting GJH.