Shoulder Instability

Concise description on shoulder instability to understand.

1. Shoulder Instability Dr. Atif Shahzad PGR Orthopedic Dept. SHL

2. DEFINITION: Instability: I nability to maintain the humeral head in the glenoid fossa. Includes a spectrum of disorders Dislocation Complete loss of glenohumeral articulation Subluxation Partial loss of glenohumeral articulation with symptoms Laxity Incomplete loss of glenohumeral articulation unassociated with pain

3. STABILITY Static Factors Articular Congruence Articular Version Glenoid Labrum Capsule and Ligament Dynamic Factors Rotator Cuff Biceps Tendon Scapulothorasic Motion Negative Pressure Propioception

4. OSTEOLOGY Glenoid fossa Pear shaped 7 deg. of retroversion 5 deg. of sup tilt Glenoid version 30 o anterior Humerus Neck-shaft – 130 o to 140 o Retrotorsion – 30 o

5. GLENOHUMERAL JOINT Humeral head 3x larger than glenoid fossa Ball and socket with translation 3 degrees of freedom Flex/Ext Abd /Add Int /Ext rot Plus Cricumduction

6. GLENOID LABRUM Static stabilizer contributes 20% to GH stability Fibro cartilaginous tissue Deepens glenoid(50 %) 3purposes: Inc. surface contact area Buttress Attachment site for GH ligaments

7. CAPSULE AND LIGAMENTS Capsule Attached medially glenoid fossa laterally to anatomical neck of humerus Ant cap thicker than post. 2-3 mm of distraction Little contribution to joint stability Strengthened by GHLs and RC tendons

8. GLENOHUMERAL LIGAMENTS (Superior, Middle , Inferior) SGHL O = tubercle on glenoid just post to long head biceps I = upper end of lesser tubercle Resists inf. subluxation and contributes to stability in post and inf. directions

9. MGHL O= sup glenoid and labrum I = blends with subscapularis tendon Limits ant. instability especially in 45 deg abduction position Limits ext rotation

10. IGHL O= ant. glenoid rim and labrum I= inf. aspect of humeral articular surface and anatomic neck 3 bands, anterior, axillary and posterior Acts like a sling , the most important single ligamentous stabilizer . Primary restraint is at 45-90 deg abduction.

11. Coracoacromial ligament secondary stabilizer. Coracohumeral ligament C ontribute to restraining inferior subluxation with arm at side,

12. Dynamic Factors Rotator Cuff Biceps Tendon Negative Pressure Scapulothoracic motion Proprioception

13. ROTATOR CUFF Compression enhances conformity Greater than static stabilizers Coordinated contractions/steering effect Supraspinatus most important Dynamization

14. Biceps long head , Deltoid secondary stabilizer head depressor Periscapular Muscles help position scapula and orient glenohumeral joint contributes compressive force across joint

15. SCAPULOTHORACIC MOTION 2:1 glenohumeral to scapulothoracic motion Scapulothoracic muscle (trapezius, serratus anterior, teres major, levator scapulae) less stable platform

16. NEGATIVE INTRA-ARTICULAR PRESSURE - 42 cm H 2 O in cadaver Secondary to high osmotic pressure in interstitial tissues Only clinically important in the arm at rest in adduction Lost with lax capsule or defect

17. PATHOANATOMY OF SHOULDER INSTABILITY Laberal Lesions – Bankart – Reverse Bankart – SLAP lesions Capsular Injury – Intrasubstance Tear – HAGL – Capsular Laxity Bone Loss – Glenoid – Humeral Head-Hill-Sachs Lesion

18. BANKART LESION. The traumatic detachment of the glenoid labrum has been called the Bankart lesion . 85%

19. HILL-SACHS LESION This is a defect in the posterolateral aspect of the humeral head.

20. INSTABILITY Classification: Frequency Etiology Direction Degree

21. Frequency Acute Recurrent Fixed (chronic) Etiology Traumatic event (macrotrauma) Atraumatic event (voluntary, involuntary) Microtrauma Congenital condition Neuromuscular condition ( epilepsy , seizures)

22. Directions of instability Anterior Posterior Inferior Superior Multidirectional Degree Subluxation Dislocation

23. SPECTRUM Traumatic Microtrauma Atraumatic Less laxity More laxity Unidirectional Multidirectional

24. EVALUATION OF INSTABILITY History Age Trauma-Duration Associated Pain Sports, throwing or overhead activities Voluntary subluxation “Clunk” or knock Fear-Limitation of Movements Hx dislocationsand energy associated Hx 1st dislocation or injury Subsequent dislocations/ subluxations

25. Physical Examination Inspection Palpation ROM Winging Neurovascular testing Generalized ligamentous laxity Instability tests

26. Sulcus sign Drawer tests Load & Shift test

27. Apprehension test Jobe’s Relocation Jerk test Fulcrum Grade = 1 - 4

28. DIAGNOSIS X-rays CT Scan MRI Arthroscopy

29. RADIOLOGY X-Rays Identify Bankart or Hill-Sachs Lesion

30. AP VIEW

31. Axillary View

32. Scapular Y-View

33. Stryker view Humeral Head Defect

34. Apical Oblique view Glenoid rim lesion

35. West Point Axillary view Anteroinferior glenoid rim

36. ANTERIOR DISLOCATION 97% of recurrent dislocation abduction , extension and external rotation subcoracoid subglenoid subclavicular Associated Injuries: Fractures Head & Neck Rotator Cuff Tears > 40 y/o = 30 % > 60 y/o = 80%

37. Neurologic Injury Axillary nerve 10-25% incidence 1st time. 2-5% in recurrent dislocators Tx: “watchful expectancy” Poor prognosis if no recovery by 10 wks Vascular Injury Axillary artery 2nd part thoracoacromial trunk

38. TREATMENT NONOPERATIVE Closed Reduction Immobilization-Sling Analgesics Rehabilitation ROM Strengthening exercises

39. Treatment of 1st time dislocators : 2 groups Immobilize x 4wks 80% recurrence Surgical repair 14% recurrence

40. TREATMENT OF RECURRENT ANT . DISLOCATION Non-operative Tx: Only 16% traumatic respond 80% atraumatic respond Poor response to non operative Tx Surgical stabilization Open or arthroscopic

41. MATSEN'S CLASSIFICATION TUBS: Traumatic Unidirectional Bankart lesion Surgery is often necessary . AMBRI: Atraumatic Multidirectional Bilateral Rehabilitation is the primary mode of treatment .    Inferior capsular shift & internal closure often performed.

42. OPERATIVE TREATMENT: Capsulolabral Repair Bankart Modified Bankart Subscapularis Procedures Putti-Platt Magnuson-Stack Coracoid Transfer Procedures Bristow Latarjet

43. POSTERIOR DISLOCATION Incidence : < 5% all shoulder dislocations 3% of recurrent

44. Mechanism: Axial load Flexed/Adduction Bench press-“ lock out” Swimming- pull thru Rowing Football Offensive Lineman

45. Examination S hift & load test Post. Apprehension test Jerk test Kim test Imaging studies X-ray CT MRI

46. TREATMENT Non Operative Immobilization Protection Rehabilitation 70-90% improve Functional disability improved Instability not eliminated

47. Operative Management Overall 50-95 % success Higher recurrence vs ant. instability procedures Soft Tissue Procedures Posterior Capsulorrhaphy Reverse Putti-Platt (IS Capsular Tenodesis ) McLaughlin Bone Procedures Posterior Glenoid Osteotomy Posterior Bone Block

48. REHABILITATION Immobilization in first 4 weeks No ext rotation Abduction less than 45 ° Isometric resistance exercises Graduated in 4 – 8 weeks ↑ ROM Graduated weight training Return to sport Non contact = 6 weeks contact = 12 weeks

49. THANKS