This document discusses the complexities of shoulder instability, emphasizing the delicate balance of soft tissues that support the shoulder joint. It highlights the challenges in diagnosis and treatment, including the spectrum of associated pathologies and potential complications arising from surgical interventions. The text advocates for a comprehensive evaluation and treatment approach, mentioning the importance of restoring shoulder balance during repair procedures.

1. Unstable Shoulder:
Current Concepts
Vivek Agrawal, MD
The Shoulder Center
12188A North Meridian
Carmel, Indiana

2. Unstable Shoulder

3. Why is an Unstable Shoulder so
common?
• Flat socket
(glenoid) means
that soft tissues
(labrum, capsule,
ligaments,
muscles) provide
most of the support

4. Unstable Shoulder
• A delicate balance of
all these tissues
keeps the shoulder
balanced and stable
• Injury, overuse, or
compensation can
disrupt this balance.

5. Circle Concept

6. Unstable Shoulder
Bumper Cushion Circle Concept

7. What is Shoulder Instability?
• Wide variation in diagnostic
and treatment criteria even
among shoulder surgeons.
– Chahal, J., Clin. J. Sports Med
• With the advances in modern
arthroscopic diagnosis and
treatment this may reflect a
gradual transition from an
etiology based diagnosis and
treatment methodology to one
that is based on the anatomic
sites of pathology.

8. What is posterior instability?
• Spectrum of disorders and pathology
– Acute only 5% of all dislocations
• Trauma, Seizure, Electrical
Shock
• Nearly 50% missed initially
– Voluntary
• Psychogenic
• Learned Behavior
– Acquired
• Largest group includes
multiple etiologies
• Circle Concept of Instability
• Multiple sites of concurrent
pathology
– Glenoid Dysplasia

9. Diagnosis
• Difficult
– Pain often the only complaint
• Primarily with activity or positional
• Flexion, adduction, internal rotation
– Instability and Neurological Complaints
• More common with underlying laxity/MDI
– Spectrum of anatomic lesions
• Historically articles have focused on a small subset
of this spectrum.

10. Diagnosis
• No single test reliable
– Jerk
– Load and Shift
– Sulcus
– Biceps/SLAP related
Tests
– Rotator Cuff
– Anterior Instability
Tests

11. Diagnosis
Posterior Instability Inferior Labrum Tear

12. Diagnosis
Posterior Instability Posterior Instability

13. Diagnosis
Brachial Plexus Shoulder Girdle Nerves

14. Suprascapular Nerve

15. Suprascapular Nerve
Arthroscopic Decompression of a Bony
Suprascapular Foramen. Arthroscopy
2009

16. Why Arthroscopic Repair?
• Allows global
evaluation, treatment,
and flexibility
• Instability is a
Spectrum
• Broad array of
coexistent pathology
• Modern techniques
offer excellent results

17. Complications
• Catastrophic Chondrolysis
– Intraarticular pain pumps
• Local anesthetic toxic to cartilage
– Knotless Suture Anchors
• Five fold failure rate for instability (4.9% vs. 23.8%)
• Windshield wiper phenomenon shears cartilage
– Thermal Shrinkage
• High failure rates
• Nerve, Capsule, and Cartilage Injury/Damage

18. Acromioplasty

19. Acromioplasty

20. Subscapularis Repair
Present in 27-35% of cases. Frequently missed.

21. Arthroscopic Repair
• The best repairs
are much more
than just a labrum
repair.
• Balance to the
entire shoulder
must be restored.
Restore Bumper Cushion

22. Arthroscopic Repair
• State of the Art
Repair requires
sutures and tying
knots
• Avoid thermal
probes and
knotless anchors
• 5:1 failure rate
knotless:knot

23. Biceps/SLAP
37% Revision Rate Reported for Type II SLAP. Provencher. AAOS 2012

24. Buford Complex

25. Unstable Shoulder
Bony Bankart Lesion Bony Bankart Lesion

26. Unstable Shoulder
Bony Bankart Reduced Bony Bankart Repaired

27. Unstable Shoulder

28. Unstable Shoulder
Wispy (Thin) Capsule No Bumper Cushion

29. Unstable Shoulder

30. Unstable Shoulder
Acute Postop Injury Percutaneous Technique

31. Unstable Shoulder
Reverse HAGL Lesion Reverse HAGL Lesion

32. Unstable Shoulder
Reverse HAGL Lesion Reverse HAGL Repair

33. Unstable Shoulder
Repaired Reverse HAGL Repaired Reverse HAGL

34. Unstable Shoulder
Hill Sachs Lesion Hill Sachs Lesion

35. Unstable Shoulder
(Remplissage)

36. Unstable Shoulder
(Remplissage)

37. Unstable Shoulder
Hill Sachs Healed Hill Sachs Healed

38. Bone Void From Metal Anchor

39. Metal Artifact
Knotless Metal Anchor Knotless Metal Anchor

40. Metal Artifact
Anterior Inferior Tear Posterior Tear

41. Resorbable Anchor Osteolysis

42. Unstable Shoulder
2 Year MRI Healed Tunnel 2 Year MRI Healed Tunnel

43. Unstable Shoulder
2 Year MRI 2 Year MRI

44. Unstable Shoulder
• Spectrum of
Pathology
– Labrum
– Biceps
– Capsule
– Rotator Cuff
– Bone
– Circle Concept
• Get a Second Opinion
– Acromioplasty
– Impingement
Diagnosis
– Biceps Tenodesis
– Knotless Anchors
– Single Anchor Repair
– Failed Shoulder
Surgery

45. Learn More at:
The Shoulder Center
Thank You!