Persistent Knee Pain in hEDS Patients

Primary Musculoskeletal Mechanisms

The American College of Rheumatology suggests that patellar instability is extremely common in hEDS patients, with recurrent subluxations or dislocations affecting the patella, triggered by a simple stair step that can cause patellar tracking abnormalities that persist 1
Ligamentous laxity and microtrauma occur in hEDS patients due to softer and less stiff connective tissue, leading to repetitive microtrauma and persistent inflammation and pain during stair climbing 2
Joint hypermobility, confirmed by Beighton scoring, predisposes to abnormal biomechanics during stair climbing, straining periarticular structures and increasing the risk of injury 1

The European League Against Rheumatism notes that fibromyalgia overlap is common in hEDS patients, particularly those with concomitant POTS, creating a chronic pain state where localized knee pain becomes part of a broader pain syndrome 3

Pelvic floor dysfunction and altered gait mechanics are highly prevalent in hEDS, creating compensatory movement patterns that overload the knee joint during stair climbing 4
Autonomic dysfunction, such as POTS, affects up to 37.5% of hEDS patients, causing orthostatic intolerance and altered proprioception or balance during stair navigation, leading to abnormal loading of the knee 3
Mast cell activation triggered by mechanical stimuli could contribute to localized inflammation and pain persistence through histamine and cytokine release 2

The American Academy of Orthopaedic Surgeons advises against dismissing persistent pain as "just hypermobility", as the pain is real, disabling, and requires active management, and ligamentous injuries and subluxations in hEDS often reduce spontaneously and may not be visible on static imaging 4

A history of patellar "giving way" or feeling the kneecap shift during the stair step suggests subluxation, and Beighton score assessment can help identify joint hypermobility 1
Postural vital signs can screen for POTS, which may have contributed to the initial injury 4, 1

Consider patellar bracing or taping during activities to provide external stability the connective tissue cannot provide, as recommended by the National Institute of Arthritis and Musculoskeletal and Skin Diseases 2