There are a number of different sub-types of Ehlers-Danlos syndrome recognised. In the hypermobility subtype, patients have musculoskeletal problems, joint instability and soft tissue injury from excessive laxity of ligaments and tendons. Many joints may be affected, but in the knee patients with this hypermobility disorder may present with patellar instability, tendinitis, bursitis and chronic pain problems. Fractures may also be common, and the diagnosis should be excuded when children seem prone to fractures. Other problems may be manifest in most of the other systems of the body.
Ehlers–Danlos Syndrome—Hypermobility Type: A Much Neglected Multisystemic Disorder. Gazit Y, Jacob G and Grahame R. Rambam Maimonides Med J. 2016 Oct; 7(4): e0034.
Ehlers-Danlos syndromes: state of the art on clinical practice guidelines. Sulli et al. RMD Open. 2018; 4(Suppl 1): e000790.