Shoulder Instability

Shoulder instability occurs when the structures that hold the shoulder in place, labrum, ligaments, and rotator cuff, are stretched, torn, or too loose. This causes the joint to partially (subluxation) or fully dislocate. It is the most common large-joint dislocation in young, active patients.

Types of Instability

Humeral head slips forward. Usually from a fall on an outstretched arm. Associated with a Bankart lesion (torn labrum) and Hill-Sachs impaction fracture.

Anterior (95%)

Humeral head slips backward. Often missed. Can occur from a seizure, electric shock, or fall on a flexed adducted arm. Also seen in weightlifters.

Posterior

Significant glenoid bone loss (>20-25%) or large Hill-Sachs lesion makes soft-tissue repair alone insufficient. Requires the Bristow-Laterjet procedure.

Bony

MDI (Multidirectional instability)

Instability in more than one direction, without a specific traumatic event. Associated with generalised joint laxity. Physiotherapy is mainstay of treatment.

Symptoms

  • Feeling of the shoulder giving way - particularly with the arm raised and rotated outward

  • Repeated dislocations - subsequent episodes become progressively easier to trigger

  • Apprehension and muscle guarding when placing the arm in a vulnerable position

  • Pain and weakness, particularly in throwing or overhead athletes

⚠ After a first-time traumatic dislocation, go to A&E for the shoulder to be relocated under sedation. Do not attempt to reduce the shoulder yourself. X-rays are needed to exclude a fracture before and after reduction.

Surgical Options

Arthroscopic Bankart Repair

The torn labrum and capsule are reattached to the glenoid rim using suture anchors through keyhole incisions. Procedure of choice when bone loss is <20% and patient is not a high-risk contact athlete.

Re-dislocation rate: 5-10%. A large Hill-Sachs lesion may require a Remplissage procedure to ‘fill-in’ the defect.

Bristow-Laterjet Procedure

The coracoid process with its attached conjoined tendon is transferred to the front of the glenoid. Addresses bone loss and creates a dynamic sling. Best for contact athletes and patients with glenoid bone loss >20-25%.

Re-dislocation rate: 1-3%.

RECOVERY AFTER SURGERY

  • Arm in sling. Gentle hand, wrist, and elbow movements only. The repair must be protected from external rotation stress.

  • Sling discontinued. Active-assisted movement begins. Mobilise to full active movements..

  • Progressive strengthening. Most patients regain comfortable daily use. Driving may resume around 6 weeks with surgeon clearance.

  • Sport-specific rehabilitation. Non-contact sport at 4-5 months; full contact sport at 6 months.

FREQUENTLY ASKED QUESTIONS

  • In patients under 25 who play contact sport, recurrence rates without surgery exceed 80-90%. In older, less active patients, non-surgical management with physiotherapy is more likely to be successful.

  • Some mild restriction of external rotation (10-15°) is common after Bankart repair and is intentional. The Latarjet procedure generally preserves more rotation. Most patients regain full functional range with physiotherapy.

This guide is intended for patient education purposes and does not replace a formal surgical consultation. Treatment decisions are always individualised based on your specific history, examination findings, and imaging. Please discuss your symptoms and management plan directly with your orthopaedic surgeon.