Multidirectional Instability (MDI) of the Shoulder
What Is Multidirectional Instability?
Multidirectional Instability (MDI) is a condition in which the shoulder joint becomes unstable in two or more directions, typically anterior (forward), posterior (backward), and/or inferior (downward). Unlike traumatic dislocations, MDI usually develops over time and is often related to generalized ligamentous laxity (looseness).
Patients with MDI may not experience full dislocations but often report symptoms of the shoulder “slipping,” “giving out,” or feeling unstable during certain movements — particularly overhead activities.
Causes and Risk Factors
Congenital hypermobility or connective tissue disorders (e.g., Ehlers-Danlos Syndrome)
Repetitive overhead activity (e.g., swimmers, gymnasts, weightlifters)
Poor posture or scapular mechanics
Inadequate rotator cuff and shoulder blade muscle control
Family history of joint laxity or instability
Symptoms
Sensation of the shoulder “slipping” out of place in multiple directions
Vague shoulder discomfort or deep aching pain
Clicking or popping with motion
Fatigue or weakness during overhead activity
Difficulty with throwing, lifting, or pushing motions
In some cases, voluntary dislocation or subluxation
Diagnosis
Detailed physical exam focusing on direction and extent of instability
Sulcus sign, apprehension-relocation test, and load-and-shift tests may reveal laxity
Assessment for systemic hypermobility (e.g., Beighton score)
MRI or MR arthrogram to assess labral integrity or rule out other soft tissue damage
Treatment
Non-Surgical Treatment
First-line approach for most cases of MDI
Structured physical therapy program:
Focus on scapular stabilization
Strengthening rotator cuff and dynamic stabilizers
Neuromuscular re-education
Postural correction and activity modification
Bracing may be considered for athletes during sport
Surgical Treatment
Reserved for patients with:
Persistent instability after at least 6 months of rehab
Structural labral or capsular injury
Procedures include:
Capsular plication (tightening of the joint capsule)
Arthroscopic thermal capsulorrhaphy (rarely used today)
Success depends on identifying the direction of instability and correcting muscular imbalances
Recovery Outlook
Most patients respond well to non-surgical therapy
Surgical recovery:
Sling for 3–4 weeks
Progressive physical therapy over 4–6 months
Return to full activity typically by 6–9 months
Compliance with rehab is critical to long-term success
Why Kerlan Jobe Institute?
At Kerlan Jobe Institute, we recognize that multidirectional instability is often misdiagnosed or undertreated. Our shoulder specialists excel in identifying the unique patterns of instability and providing customized treatment — whether through high-level rehabilitation programs or precise surgical correction — to restore strength, stability, and confidence in the joint.