Joint hypermobility

Definition and Understanding of Hypermobility

Hypermobility refers to excessive flexibility of the periarticular tissues, including the ligaments, tendons, muscles, and joint capsules. Hypermobility is therefore responsible for different joint play, which can lead to instability in the joints of the ankle and foot, as in any patient. In particular, we distinguish between physiological hypermobility, which allows the joints to function normally, and pathological hypermobility, which causes major joint instability. Understanding these differences, as well as the role of anatomical structures and tissue laxity, is essential to adapt therapeutic management in hypermobile patients. Hypermobile patients constitute a separate group.

Causes and Risk Factors of Joint Hypermobility

The origins of joint hypermobility are multiple and result from the interaction of genetic, traumatic, hormonal, and familial factors. On a genetic level, hypermobility often reflects an abnormality in the quality of collagen and connective tissues, observed in hereditary syndromes such as Ehlers‑Danlos syndrome, Marfan syndrome, as well as in trisomy 21, where excessive ligament laxity is accompanied by increased tissue fragility. Repeated injuries, especially ankle sprains that are insufficiently treated, can stretch ligaments in several areas, leading to localized or more widespread hypermobility, and chronic instability that promotes recurrent sprains of the ankle and foot.

On a hormonal level, pregnancy induces from the first trimester an increase in hormonal levels ofestrogen and progesterone, which increases ligament laxity that will be necessary in the pelvis for childbirth.

Finally, the presence of a family history of hypermobility, even in the absence of a formally diagnosed syndrome, highlights the importance of a constitutional predisposition and justifies a personalized clinical assessment in order to define the most appropriate follow-up and management strategy for each patient.

Symptoms and Diagnosis of Joint Hypermobility

Patients with joint hypermobility may report intermittent joint pain or chronic pain resulting from excessive stress on overly loose ligaments and impaired proprioception, which promotes the development of microtrauma and repeated inflammations within the joint. This ligamentous instability often leads to recurrent sprains and tendon dislocations (especially in the ankle) that can occur even during minor trauma and increase the long-term risk of complications such as osteoarthritis. Concurrently, the functional overload of the muscles and tendons compensating for ligament weakness often leads to tendinitis, accompanied by a sensation of instability that can limit sports practice and daily activities.

Diagnosis is based on a standardized clinical assessment, the main screening tool being the Beighton clinical score. This test, which consists of five maneuvers rated out of nine points, is considered positive from 5/9 in adults (4/9 over the age of 50), a threshold adopted by the International Consortium to suggest generalized joint hypermobility and to guide further investigation to differentiate benign hypermobility, hypermobility spectrum disorders, and Ehlers-Danlos syndrome.

The combined use of the Beighton score and specific clinical tests (for example, ankle laxity assessment) along with a focused interview (five-point questionnaire) allows confirmation of the diagnosis, evaluation of its severity, and early identification of potential complications. Early diagnosis is essential to implement appropriate management (physiotherapy focused on muscle strengthening, proprioceptive exercises, and possible use of orthotics) in order to reduce the risk of traumatic recurrence, preserve joint function, and improve the patient's quality of life.

Impact on Anatomical Structures of Hypermobility: Bones, Cartilage, Tendons, and Ligaments

Joint hypermobility increases the vulnerability of the musculoskeletal system by disrupting the normal stability of the joints. On the bone level, excessive ligament elasticity increases susceptibility to microtraumas and sprains of the ankle, hindfoot, and midfoot. Ankle fractures are also among the complications reported in hypermobility patients. This same instability leads to abnormal mechanical stress on the cartilage, promoting its premature wear and the joint degeneration characteristic of secondary osteoarthritis. The tendons, forced to compensate for the lack of ligament support, are exposed to chronic overload, multiplying the risks of chronic tendinitis, especially of the Achilles tendon, the fibular tendons, and the posterior tibial tendon. In cases of repeated overuse, tendon tears may appear, with a risk of tendon ruptures in cases of cortisone infiltration into the tendon sheaths.

Finally, the ligaments themselves, whose stabilizing function is compromised by hypermobility, undergo increased stress which results in a high frequency of sprains, reinforcing joint instability and exposing to new injuries.

Treatment Options in Joint Hypermobility

Several therapeutic strategies can help alleviate symptoms related to hyperlaxity:

• Appropriate rehabilitation: muscle strengthening and proprioceptive exercises as part of a personalized physiotherapy program.
• Preventive strategies: adaptation of physical activity, ergonomic and educational advice.
• Pain management: use of medication to relieve inflammation and pain.
• Surgical interventions: in specific cases where joint instabilities become severe, surgical procedures may be recommended.

Each solution is evaluated according to the patient's profile in order to achieve lasting improvement of joint stability.

Joint hypermobility by the Foot and Ankle Clinic

At the Foot and Ankle Clinic, we provide care for patients with joint hyperlaxity. We use minimally invasive techniques (arthroscopy and percutaneous procedures) that significantly reduce the risk of complications while allowing for potentially quicker recovery. However, open surgical procedures are regularly offered to hyperlax patients, as tissue dissection increases postoperative scar tissue fibrosis, allowing for a temporary boost in joint stability during the rehabilitation period.

Each treatment plan is accompanied by regular follow-up and a personalized rehabilitation program, tailored to each stage of recovery.

Characteristics of joint hypermobility

In cases of joint hypermobility, personalized assessment and appropriate follow-up can significantly improve quality of life.

People with hypermobility form a distinct group of patients. The aim of ankle ligament reconstruction, for example, is to achieve ligament stiffness that allows for effective rehabilitation primarily focused on proprioception and muscle strengthening. Regaining joint mobility is not an issue, as hypermobile individuals will recover all their joint mobility a few months after the surgical procedure.

Certain ankle ligament reconstructions require augmentations with surgical strips made of very strong tissue to ensure joint stability. In hypermobile patients, it will often be necessary to subsequently remove this material due to the limitation in joint mobility experienced.