1. Shoulder Instability April 2012 Ryan

2. Shoulder The shoulder is the most mobile joint in the body The shoulder is the most mobile joint in the body It’s a minimally constrained articulation that must balance mobility with stability It’s a minimally constrained articulation that must balance mobility with stability Not always successful, as it is the most likely joint to dislocate Not always successful, as it is the most likely joint to dislocate

3. Laxity vs. Instability Laxity: Asymptomatic passive translation of humeral head on the glenoid Instability:Excessive symptomatic translation of humeral head on glenoid during active motion

4. Definition of Terms Direction: Anterior vs. Posterior vs. MDI Timing: Acute vs. Chronic Frequency: Single vs. Recurrent Etiology: Traumatic vs. Atraumatic Degree: Subluxate vs. Dislocate Volition: Voluntary vs. Involuntary

5. The Stable Shoulder Static Restraints Static Restraints –Bone Glenoid Glenoid Humerus Humerus –Ligaments –Labrum –Capsule –Negative pressure –Adhesion/cohesion Dynamic Restraints Dynamic Restraints –Rotator Cuff Concavity compression Concavity compression –Biceps –Deltoid –Scapula Rotators

6. Static: Bone Glenoid Glenoid –Articular Version 30 anterior on Chest wall 30 anterior on Chest wall 3 upward tilt 3 upward tilt 7 retroversion (25% of people of anteversion 2-10) 7 retroversion (25% of people of anteversion 2-10) Bare spot in the center and more cartilage in periphery (increases the depth) Bare spot in the center and more cartilage in periphery (increases the depth) –Bone loss Fracture Fracture Dysplasia Dysplasia

8. Static: Bone Humerus Humerus –Version 130 neck shaft angle 130 neck shaft angle 30 retroversion 30 retroversion –Articular Surface More of sphere in the center and elliptical in the periphery More of sphere in the center and elliptical in the periphery –In any position, there is only 25-30% of the humeral head in contact with the glenoid Importance of soft tissue for stability Importance of soft tissue for stability –Congruity Almost a perfect match with glenoid (<3mm) Almost a perfect match with glenoid (<3mm) Congruity less important than total surface area Congruity less important than total surface area –Hill-Sachs Reverse Reverse Engaging Engaging

9. Static Restraints Labrum Labrum –Anchor for capsule & ligaments –Deepens the concavity of the socket Increases depth of socket by 50% (5- 9mm) Increases depth of socket by 50% (5- 9mm) –Increases surface area –Bumper Resection decreases resistance to translation by 20% Resection decreases resistance to translation by 20%

10. Static Restraints Capsuloligaments Coracohumeral ligament Coracohumeral ligament –Primary restraint to inferior translation of the ADDucted arm and to ER SGHL SGHL –Primary restraint to ER in ADDucted or slightly abducted arm –Primary restraint to inferior translation in the ADDucted arm MGHL (absent in 30-40%) MGHL (absent in 30-40%) –Primary stabilizer to anterior translation with the arm abducted to 45 (45-90) IGHLC- A&P bands, hammock IGHLC- A&P bands, hammock –Primary stabilizer for anterior and inferior instability in abduction –Posterior band in flexion/adduction to posterior instability

11. Static Restraints Adhesion/cohesion Adhesion/cohesion –Attraction of joint fluid to itself and to the articular surface –Cover slip to slide Suction Cup Suction Cup –The glenoid and labrum act as a suction cup Negative joint pressure Negative joint pressure –Analogous to pulling on the plunger of a plugged syringe –Venting the joint allows 55% increase in anterior translation

12. Dynamic Restraints Rotator Cuff Rotator Cuff –Concavity-Compression Enhances the conformity of the joint and increases the force required to translate Enhances the conformity of the joint and increases the force required to translate –Could be more important than ligament restraints –RC blend into ligaments and could provide dynamic restraints through them –Importance of RC strengthening in Rehab –Anterior-superior escape in cuff tear arthropathy (CTA)

13. Dynamic Restraints Biceps Biceps –Difficult to determine its actual contribution –Many studies with differing results –? Function as a humeral head depressor Deltoid Deltoid –Increase activation in unstable shoulder

14. Dynamic Stability Scapular Rotators Scapular Rotators –Trapezius, Rhomboids, Lat, Serratus, Levator –2:1 ratio of GH motion to Scapulothroacic motion –Provide stable platform beneath humeral head –Importance rehab to include scapular rotators Proprioception Proprioception –Mechanoreceptors send message in reflex arc to control shoulder –Increased hand position error in pts with MDI –Surgery improves GH proprioception

15. Breakdown of Stability Minimal loads: Minimal loads: –Negative intraarticular pressure –Adhesion/Cohesion –Suction Cup Moderate loads, Mid-range: Moderate loads, Mid-range: –Concavity-compression –Labrum –Scapulothoracic Rhythm & Proprioception Large loads, End-range: Large loads, End-range: –IGHL

16. Pathoanatomy of Instability: Bankart Lesion “Essential lesion” “Essential lesion” Separation of inferior capsulolabral complex from glenoid neck Separation of inferior capsulolabral complex from glenoid neck –Broca and Hartmann 1890 – see figure –Perthes 1906 –Bankart 1923, 1939

17. Bankart Lesion: 1. Disrupts the concavity compression 2. Eliminates the bumper 3. Decreases depth by 50% 4. Detaches capsuloligamentous structures 5. May eliminate the negative intraarticular pressure

18. Pathoanatomy of Instability: Capsular injury Bankart Less often considered the all-or- none “Essential lesion” but still the most common lesion: 62-97% Bankart Less often considered the all-or- none “Essential lesion” but still the most common lesion: 62-97% –Simulation of Bankart results in only minimal increase in translation –Plastic deformity of the capsule is required ALPSA: anterior labral periosteal sleeve avulsion ALPSA: anterior labral periosteal sleeve avulsion HAGL/BHAGL: humeral avulsion of the glenohumeral ligaments HAGL/BHAGL: humeral avulsion of the glenohumeral ligaments GLAD: glenolabral articular disruption GLAD: glenolabral articular disruption

19. Pathoanatomy of Instability: ALPSA Lesion

20. Pathoanatomy of Instability: HAGL Lesion

21. Pathoanatomy of Instability: Bone Loss Humerus Humerus –Hill-Sachs or Reverse Hilll-Sachs –60-90% of primary anterior dislocations –90-100% in recurrent dislocations –25% of subluxations –Larger defects Longer dislocations Longer dislocations Recurrent Recurrent Inferior Inferior –>30% defect may lead to recurrent instability Tendon ( Remplissage) Tendon ( Remplissage) Allograft Allograft Replacement Replacement

22. Pathoanatomy of Instability: Bone Loss Glenoid Glenoid –Bony Bankart –Erosion from Recurrent dislocation –Glenoid defects in 22% acute dislocations and 73% of patients with recurrent –Defects < 15% repair labrum/capsule –Bigliani – loss of > 25% warrants bony reconstruction –Burkhart – inverted pear glenoid requires bony reconstruction 61% recurrence with inverted pear or engaging Hill Sachs vs 4% recurrence without 61% recurrence with inverted pear or engaging Hill Sachs vs 4% recurrence without Measure bare spot to anterior rim. Measure bare spot to anterior rim. Reconstruction Reconstruction –Iliac crest –Coracoid (Latarjet) –Lateral aspect of tibial plafond

23. Provencher, Arthroscopy 2009

25. Pathoanatomy of Instability: Associated Injuries Rotator cuff tear Rotator cuff tear –Under 30 rare –Over 40 85% 85% Nerve injuries Nerve injuries –Axillary: up to 33% –Musculocutaneous

26. Clinical Evaluation Etiology: Traumatic vs. Atraumatic Direction: Ant vs. post vs. MDI Timing: Acute vs. chronic Frequency: Single vs. recurrent Degree: Sublux vs. Dislocate Volition: Voluntary vs. involuntary

27. Clinical Evaluation History History –Acute vs. Chronic –Isolated vs. recurrent –Dislocation vs. subluxation –Direction –Past treatment PE PE –ROM –Strength –Neurovascular exam –Atrophy –Winging –Sulcus –Load and Shift –Apprehension –Relocation –Jerk Pts w/ bony defects should have marked apprehension and at lesser angles of abduction and ER Pts w/ bony defects should have marked apprehension and at lesser angles of abduction and ER Radiographs and/or CT Radiographs and/or CT EUA EUA Arthroscopy Arthroscopy

28. West Point view Prone, 25 degree from midline, directed through axilla Itoi – correlated West Point view with CT for glenoid bone loss Axillary view underestimates

29. Hill Sachs evaluation Stryker notch view – –Hand to head, elbow up – –Beam angle up 10 degrees – –Centered over coracoid CT preferred over MRI – –MRI underestimates bone defect

30. Anterior Dislocation 85-90% of dislocations 85-90% of dislocations Treatment Treatment –Prompt atraumatic reduction –Immobilization Risk of Recurrence Risk of Recurrence –Age (<30) –Activity level –Compliance with rehab –Contralateral shoulder instability –Bony defects

32. Emergent Management  Immobilization (duration)  No change in outcome ? (Hovelius et al., 1983; Rowe et al. 1961)  One week (Kazar et al., 1969)  Three weeks (Kiviluoto et al., 1980; Stromsoe et al 1980)  Dependent on age ?  >40 1 week  <40 3 weeks

33. Emergent Management  Immobilization (position)  Internal rotation and adduction (sling)  Labrum anatomically better position in ER (Itoi et al, 2001)

34. Emergent Management  Immobilization (position)  Clinical follow-up for 15 months (Itoi et al., 2003)  No recurrent dislocation with ER immobilization  30% dislocation with IR immobilization  0% vs. 45% for patients younger than 30

35. Goals of Rehabilitation Return dynamic stabilizers to functional state Return dynamic stabilizers to functional state Protect healing of static stabilizers Protect healing of static stabilizers Minimal immobilization Minimal immobilization Early ROM, avoid ER Early ROM, avoid ER Strengthening in plane of scapula Strengthening in plane of scapula Bracing/harnessing for return to sports Bracing/harnessing for return to sports

36. Anterior dislocation Surgery Surgery –Early vs. Late <30 y/o surgery may be first line –Open vs. Arthroscopic Open still “gold standard” Reader beware –Some open techniques not anatomic (high OA) –Early scopic studies with poor techniques and implants

37. Scope vs. Open Arthroscopic Arthroscopic –Minimizes dissection –Decreased damage to soft tissues Subscap Subscap –Earlier Rehab –Better ROM –Hard to over tighten –Better visulaization –Treat other pathology –Learning Curve –Outpatient Open Open –Gold standard –Initially lower recurrence Possibly over constrained –Still required for Large bony defects HAGL? Capsular insufficiency Revision –Cosmesis –OR time –Inpatient

38. Scopic vs. Open Open (recurrence) Open (recurrence) –Putti-Platt 3.0% –Mag-Stack 4.1 –Eden-Hybbinette 6.0 –Gallie2.9 –DuTolt & Roux 2.0 –Bristow1.7 –Bankart3.3 –Capsulorrhaphy 3.4 –Classic Bankart Rowe and Bankart Rowe and Bankart –96% success Scopic Anchors Scopic Anchors –Bacilla7% –Gartsman 8 –Cole0 –Kim4 –Kim10 –Abrams6.6 –Mazzocca 11 –Fabbriciani (’04)0 –Recent scopic anchor technique also with 96% success

41. Arthroscopy, 2010

42. Posterior Acute posterior Acute posterior –<5% –Unrecognized in 50-80% of patients initially Chronic Chronic –> 6weeks locked out the back Volitional Recurrent Volitional Recurrent –Habitual dislocator (psych issues) –Voluntary (can selectively fire muscles) May become involuntary May become involuntary Dysplastic Recurrent Dysplastic Recurrent –Hypoplasia, glenoid or humeral retroversion

43. Posterior Treatment Treatment –Nonop Rehab focusing on infraspinatus/teres minor/posterior deltoid/scapula Rehab focusing on infraspinatus/teres minor/posterior deltoid/scapula 63-68% success 63-68% success –Surgery OPEN vs. Scopic OPEN vs. Scopic Capsulorrhaphy/shift Capsulorrhaphy/shift Reverse bankart Reverse bankart Bone block Bone block Glenoid osteotomy Glenoid osteotomy Infraspinatous Capsular tenodesis Infraspinatous Capsular tenodesis –Results 85-91% success 85-91% success

44. MDI Subluxate or dislocate in multiple directions, with concurrent reproduction of symptoms in at least 2 directions, one being inferior Subluxate or dislocate in multiple directions, with concurrent reproduction of symptoms in at least 2 directions, one being inferior Symptoms usually in mid-range of motion (ADL’s) Symptoms usually in mid-range of motion (ADL’s) Positive Sulcus with symptoms Positive Sulcus with symptoms Pathology Pathology –Widened Rotator Interval –Redundant inferior capsule –Collagen abnormality? –Mechanoreceptor –Abnormal muscle control

45. MDI Nonop – Rehab Nonop – Rehab –Rockwood 88% success rate –Must prove that they will be compliant Surgery Surgery –Open or scopic inferior shift Scopic Scopic –Posterior capsule –Anterior capsule –Rotator Interval –Post-op Cast or brace Results Results –Pollack 94% –Brems85% –Hawkins 60% –Savoie88% –Gartsman94% –McIntyre95%

46. Questions?