ABC Medical Center > Diseases > Shoulder Instability

What is shoulder instability?

26 January 2026

Also known as glenohumeral instability, this condition consists of the abnormal and excessive movement that occurs in the interaction between the humeral head (a ball-shaped joint) and the glenoid cavity (a shallow socket) of the shoulder blade or scapula.

Shoulder instability also occurs when the head of the humerus comes out of the glenoid cavity, which can be:

  • Dislocation: When it comes out completely.
  • Subluxation: When it comes out partially.

The scapular stabilizers are a set of muscles that provide stability to the shoulder, which is why it’s important to do exercises to strengthen them to prevent this injury.

Among the possible causes of shoulder instability are:

  • Blows.
  • Falls.
  • Repetitive movements.
  • Excessive stretching.
  • Abrupt and forced movements.
  • Practicing sports that involve constant arm and shoulder movements.
  • Performing activities that require continuous arm and shoulder movements.

The most frequently occurring types of injury are:

  • Bankart lesion: A tear of the labrum and the scapular glenohumeral ligaments.
  • Laxity of the shoulder ligaments caused by excessive stretching.
  • Fractured edges of the glenoid cavity.
  • Rotator cuff tear.

Signs and symptoms Shoulder Instability

The symptoms are:

  • Locked joint.
  • Intense pain.
  • Inability to move the shoulder.

Diagnosis and treatment Shoulder Instability

Once the orthopedist analyzes your symptoms and clinical history, they will perform a physical examination, paying special attention to the injured shoulder. They will ask you to attempt movements and postures to observe painful reactions and dynamic limitations.

Furthermore, to rule out other conditions and confirm the diagnosis, they will request imaging studies such as:

  • X-rays.
  • Ultrasound.
  • Magnetic Resonance Imaging (MRI).

The treatment to follow will depend on the severity of the instability and the type of injury. For mild cases without trauma, the following are indicated:

  • Analgesics (painkillers).
  • Anti-inflammatories.
  • Physical therapy.

When conservative therapy is ineffective or the injury is severe, the only option is surgical repair, either by arthroscopy or open surgery. There is also the alternative of the Latarjet procedure, which prevents the humeral head from slipping out of the scapular socket.

At the Orthopedics and Traumatology Center, we seek to improve the lives of patients restricted or immobilized by musculoskeletal disorders or injuries. We specialize in the care of the musculoskeletal system by integrating the latest medical, biological, and technological advances, in strict adherence to the highest international standards of patient care.

Related centers and departments Shoulder Instability

Orthopedics and Traumatology Center
High Specialty Surgery Center
Radiology and Molecular Imaging
Clinical Laboratory

Sources:

  • centralcoastortho.com
  • aaos.org
  • orthoinfo.aaos.org
  • cun.es
  • fisify.com
  • mayoclinic.org
  • medlineplus.gov
  • topdoctors.es
  • medigraphic.com
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  • Eden-Hybinette para la inestabilidad del hombro anterior. Acta Ortop Mex. 2021 Nov-Dic;35(6):534-538.
  • doi:10.35366/105707.
  • Villalobos MJ, Jacobo-Nájera I, Téllez-Ávila JC, et al. Experiencia en el manejo de la inestabilidad anterior de
  • hombro con técnica de remplissage . Ortho-tips. 2021;17(2):108-111. doi:10.35366/99905.
  • Alvarez-López A, Fuentes-Véjar R, Soto-Carrasco SR, et al. Medición del defecto óseo del reborde glenoideo
  • anterior en la inestabilidad glenohumeral. AMC. 2020;24(1):144-154.
  • Rojas-Viada J, Águila-Miranda R, Oyarzún-Martínez A, et al. Inestabilidad anterior de hombro con defecto óseo no crítico: ¿Bankart-Remplissage o Latarjet?. Acta Ortop Mex. 2021 Sep-Oct;35(5):417-424.

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