Multidirectional Shoulder Instability (MDI)

Abnormal amount of excursion of the humeral head on the glenoid in all directions. MDI peaks in second and third decades of life

Causes
• Microtrauma from overuse, it is seen with overhead throwing, volleyball players, swimmers, gymnasts.
• Generalized ligamentous laxity: associated with connective tissue disorders: Ehlers-Danlos and Marfan’s

Symptoms

  • pain
  • instability
  • weakness
  • paresthesias
  • crepitus
  • shoulder instability
  • during sleep

Physical exam

The patient must have instability in 2 or more planes (anterior, posterior, or inferior) to be defined as MDI.
The signs of generalized hypermobility – generalized ligamentous laxity = Beighton’s criteria >4/9

  • able to touch palms to floor while bending at waist (1 point)
  • genu recurvatum (2 points)
  • elbow hyperextension (2 points)
  • MCP hyperextension (2 points)
  • thumb abduction to the ipsilateral forearm (2 points)

Non Operative Therapy

Concentrates on:
1. Core stability
2. Scapula Stability
3. Muscle patterning
4. Proprioception
5. Functional Rehab.

Surgery

Treat ALL Pathology present:
• Labral (Anterior, Posterior, Superior)
• Capsule Laxity
• Bone Defects (Humeral Head, Glenoid)
• Cuff tears

Summary

Treat ALL Pathology present:
• Labral (Anterior, Posterior, Superior)
• Capsule Laxity
• Bone Defects (Humeral Head, Glenoid)
• Cuff tears