Multidirectional shoulder instability

What does multidirectional instability mean?

In multidirectional shoulder instability, the joint capsule and ligaments are too flexible overall. Combined with inadequate muscular guidance, the humeral head can slide excessively in the socket. This leads to insecurity, pain and functional restrictions in everyday life, work and sport.

• Often atraumatic (without a major accident) and possible on both sides
• Increased in hypermobility or connective tissue variants
• Complaints often increase with overhead or tensile loads
• Therapy focus: neuromuscular control and capsule/muscle balance

Anatomy: Why the shoulder needs stability and control

The shoulder joint (glenohumeral joint) offers maximum mobility - and is therefore dependent on a finely coordinated interaction of static and dynamic stabilizers.

• Static stabilizers: articular lip (labrum), capsule, ligaments (e.g. glenohumeral ligaments)
• Dynamic stabilizers: rotator cuff, long biceps tendon, shoulder muscles, scapular guides (serratus anterior, trapezius, rhomboids)
• Scapular control: The position of the shoulder blade controls the socket angle and thus the centering of the humeral head

Causes and risk factors

MDI usually arises from a combination of tissue laxity and neuromuscular imbalance. A single severe trauma is not typical, but can trigger or intensify symptoms.

• Congenital hypermobility/connective tissue variants (e.g. increased Beighton score)
• Repeated microtraumas from overhead sports (swimming, volleyball, handball, climbing)
• Scapular dyskinesia (improper movement of the shoulder blade)
• Previous dislocations or subluxations
• Hormonal factors and growth phases in adolescents
• Concomitant factors: low trunk/core stability, muscular fatigue

Symptoms and warning signs

• Feeling of insecurity, “folding away” or giving way of the shoulder
• Stress-related pain, especially a. during overhead and pulling movements
• Snapping, clicking or rubbing in the joint
• Reduced performance in sports, rapid fatigue
• Occasional numbness/tingling with subluxation (temporary)

Warning signs that should be checked by a doctor:

• Acute, visible dislocation (luxation) with shape change
• Persistent sensory disturbances, loss of strength or blood circulation problems in the arm
• Severe pain at night after trauma
• Concomitant injuries (e.g. fall on the shoulder)

AMBRI vs. TUBS: Classification of instability

The AMBRI mnemonic aid has been established in orthopedics for classification: Atraumatic, Multidirectional, Bilateral, Rehabilitation first, Inferior capsular shift (if operation). In contrast to this is TUBS: Traumatic, Unidirectional, Bankart lesion, Surgery.

• MDI (AMBRI): usually without major trauma, multiple directions, often bilateral, first consistent therapy, if necessary capsular shift
• Traumatic dislocation (TUBS): often anterior, after accident, Bankart lesion possible, surgical stabilization more common

Diagnostics: From anamnesis to imaging

A careful clinical examination is crucial. In addition to the anamnesis, posture, scapular guidance, muscle balance and specific tests are assessed. Imaging helps to rule out accompanying lesions and assess the capsular situation.

• Inspection and functional analysis: posture, scapular dyskinesia, range of motion
• Hypermobility: Beighton score
• Specific tests: Sulcus sign (inferior laxity), load and shift (anterior/posterior), Gagey test (hyperabduction), modified apprehension/relocation tests
• Neurological status and blood flow control

• X-ray: basic diagnostics, exclusion of bony injuries
• MRI/MR arthrography: assessment of capsular laxity, labrum, rotator cuff
• Ultrasound: dynamic assessment, tendons, effusions

The diagnosis results from the overall picture. Not every positive test result means instability that requires treatment - symptoms and function are crucial.

Conservative therapy: rehabilitation first

The guideline-based treatment of MDI is a structured rehabilitation program lasting several months. The goal is to restore joint centering through scapular control, rotator cuff strengthening, and neuromuscular coordination. Patience and continuity are essential success factors.

• Home program: 3-5 days/week, short and regular
• Physiotherapy: initially 1–2 times/week, later as needed
• Aids: Taping/orthosis as feedback, possible for a short time
• Medication: if necessary, short-term painkillers after consulting a doctor
• Duration: often 3-6 months until stable

Everyday life, work and sport: Practical tips

• In everyday life, do not carry heavy bags on one side - distribute the weight
• Adjust the workplace ergonomically, rest your forearms, take a break
• Sleep: Supine position or on the unaffected side, arm well supported
• Training: slow progression, warm-up, no deep dips/excessive stretching
• Resume sports with overhead strain gradually and under control

Regenerative processes: what is realistic?

Biological injections (e.g. PRP) are not established for the actual capsular laxity of MDI. They can be discussed in individual cases with accompanying tendon irritation. The core treatment remains active rehabilitation. A decision for additional procedures is made individually and after careful information about the benefits and limitations.

Surgical options: Use capsular tightening in a targeted manner

Surgery is considered if relevant symptoms with loss of function persist despite consistent, structured physiotherapy over several months. The prerequisite is a clear clinical correlation and realistic expectations.

• Arthroscopic capsular plication/capsular shift (anterior, posterior, inferior depending on the findings)
• Rotator interval closure in selected cases
• Open inferior capsular shift (rare, special indication)

Not every patient benefits from surgery. Results are less predictable in the case of voluntary dislocations, severe generalized hypermobility, or inadequate compliance. Possible risks include stiffness, renewed instability, pain, nerve irritation or infection.

Rehabilitation after surgery

The schedule varies depending on the procedure and individual healing. Returning to overhead sports can take 4-9 months.

Prognosis and course

Many sufferers achieve significant relief of symptoms and better shoulder control with a structured rehabilitation program. Regularity, technique and adapted load management are crucial. The prognosis depends on accompanying factors (degree of hypermobility, type of sport, duration of symptoms). Long-term maintenance of the stability achieved often requires minimalist but continuous home training.

Differential diagnoses

• Rotator cuff irritation or tears
• SLAP lesions and other labral injuries
• Biceps tendon disorders
• AC joint problems
• Cervical radiculopathy, nerve entrapment (e.g. suprascapular nerve)
• Joint stiffness (frozen shoulder) – differentiation is important

Common mistakes to avoid

• Too early overhead or end-range loads without control
• Excessive passive stretching when the capsular ligament apparatus is already lax
• Unilateral strength training (chest/delta only) without scapular focus
• Irregular home program
• Quick return to competitive sport without criteria check (pain, strength, control)

Your shoulder specialists in Hamburg

In our orthopedic practice in Hamburg-Winterhude, we advise you individually on multidirectional shoulder instability - with a focus on conservative therapy, clear indications and transparent information. Address: Dorotheenstraße 48, 22301 Hamburg. Please feel free to make an appointment online via Doctolib or by email.