Posterior shoulder dislocation 2

-

1. Τακτικό μετεκπαιδευτικό πρόγραμμα ΚΕΟΧ Παθολογία - Χειρουργική Ώμου Posterior Shoulder Instability Presented By: MANOS ANTonogiannakis Κολλέγιο Ελλήνων Ορθοπαιδικών Χειρουργών Ελληνική Εταιρεία Χειρουργικής Ορθοπαιδικής και Τραυματολογία ς 9 /5/ 2014 www.shoulder.gr

2. The Shoulder Greatest Range of Motion in the Body Motion in all 3 planes of movement Prone to instability Sacrifices stability for mobility

3. What is Instability Biomechanical Dysfunction Failure of static and dynamic stabilizers Ranges from mild subluxation to traumatic dislocation

4. Contributors to stability Static stabilizers 1. ligamentous structures labrum and capsule 2. bony configuration of glenoid and humeral head Dynamic stabilizers 1. rotator cuff 2. scapula muscles

5. history Hippocrates First described reduction for posterior dislocation of the shoulder Sir Astley Cooper First described posterior dislocation in a patient with a seizure Malgaigne First described a series of 37 patients with posterior instability in 1855 before the advent of radiology

6. posterior Restraints 1. Glenoid (version and shape) Abnormalities in the glenoid shape and version has been described as more common in patients with atraumatic posterior instability. (Weishaupt,2000). The greater the retroversion of the glenoid the more prone it is to posterior dislocation.

7. posterior Restraints 2 . Capsule IGHL plays a significant role at the extremes of internal humeral rotation . Unlike the anterior structures, the posterior capsule is relatively thin with less clearly defined ligamentous components, especially superiorly above the equator .

8. posterior Restraints 3. Rotator Interval Plays an important role with the humerus in neutral rotation Incision of the rotator interval capsule increased posterior translation by 50% and inferior translations by 100%, suggesting resultant overlap in magnitude and direction of the various capsular regions to the overall instability pattern ( Harryman , 1992).

9. posterior Restraints 4 . Labrum Usually torn in Traumatic dislocations, with the formation of a posterior Bankart lesion. The importance of the posterior labrum in posterior instability has been neglected in the past. Since the advent of arthroscopy posterior labral lesions have been more commonly found and treated. Recent posterior labral lesions described: POPSLA lesion – posterior Periosteal Sleeve labral Avulsion ( Yu et al. Skel Radiol . 2002. 31:396-9) Kim’s Lesion – Incomplete & concealed avulsion posteroinferior labrum ( Kim, 2001 )

10. posterior Restraints Posterior inferior Bankart lesion

11. posterior Restraints 5. Subscapularis Blasier et al identified the subscapularis as being the muscle providing the greatest resistance to posterior subluxation of the humerus J Bone Joint Surg Am, 1997

12. Aetiology Traumatic instability typically follows a distinct history of dislocation or subluxation, sustained during a significant injury. Patients with atraumatic instability often have no history of true dislocations, but on probing there often is a history of minor trauma or repetitive microtrauma (sports). This is usually associated with capsular laxity

13. Posterior instability clinical presentation in forward flexion and internal rotation sometimes after an anterior repair of a lux shoulder 2. Locked posterior dislocation after acute trauma . Sense of insecurity and feeling of instability

14. Atraumatic posterior instability clinical presentation Frank dislocations with minimum violence often reduced by the patient Subluxations and positive apprehension sign in forward flexion and internal rotation in a loose joint individual usually teenager Pain and functional impairment in a loose joint individual, the patient mainly complaining for posterior pain in flexion internal rotation and not for instability

15. history These patients often don’t present with a typical history of true dislocations Symptoms of posterior joint pain and/or clicking. Often this the pain occurs when loading the flexed and internally rotated shoulder. This can be confused with subacromial impingement Therefore careful clinical examination is essential.

16. Clinical examination It should include all of the followin Laxity (both the shoulder and general) Stability Proprioception Psychology

17. Clinical examination www.shoulder.gr

18. Posterior dislocation Much less common than anterior ( 3 -5 %) May be difficult to diagnose and may often be missed on up to 50% standard AP view Electric shock Seizures Trauma ( alchoholics )

19. Mechanism of Injury Axial loading of the adducted, internally rotated arm because the internal rotator muscles are approx twice as powerful as the exernal rotator muscles, a sudden contraction (such as from a seizure or shock) will cause the humeral head to dislocate I nvoluntary recurrent posterior subluxation may be associated w/ high forces generated during follow thru phase of various sports activities   this develops as humerus is in adduction, flexion, and internal rotation, & maximal contractions of subscapularis and deltoid V oluntary dislocation Internal rotation – Adduction – Flexion

20. associated lesions Reverse Bankart lesion Reverse Hill-Sachs deformity Lesser tuberosity fx Posterior HAGL lesion POLPSA lesion

21. associated lesions Reverse Bankart lesion

22. Reverse Hill-Sachs deformity

23. Posterior dislocation Athletes, such as weight lifters, throwers, racket sport athletes, rugby players, and swimmers at higher risk. inherently lax shoulders (advantage for their sports but prone to instability) repetitive trauma (chronic instability )

24. Clinical examination

25. Clinical examination Attempted abduction and external rotation are painful The arm cannot be externally rotated to a neutral position There is inability to supinate Examination may resemble a frozen shoulder, especially with a chronic, unreduced dislocation Nerve and vascular injury are not common

26. Clinical examination

27. Clinical examination

28. Clinical examination

29. Locked posterior dislocation is easily missed

30. Posterior dislocation

31. Clinical examination

32. EVALUATION Radiographs ( AP and axillary views) CT with 3D reconstruction (bony lesions) MR Arthrogram . Examination under anesthesia and arthroscopy aids the diagnosis, although one should have most of the information before this.

33. X-RAYS

34. Helpful radiographic signs Lightbulb sign humeral head internally rotated tuberosity no longer project laterally

35. Helpful radiographic signs Trough line sign 2 parallel lines of cortical bone are seen on medial cortex of HH , one line is medial cortex of HH other line is “trough of impaction fx (reverse Η ill-Sachs ) anterior articular surface of HH

36. CT

37. CT

38. Decision Making If the primary abnormality is found to be structural ( eg . Bankart lesion, bony lesion or capsular injury) then surgery is often required early and the rehab follows accordingly

39. posterior instability Surgery It depends on the injuries It is essential to identify the pathology and treat accordingly

40. posterior instability Surgery Soft Tissue Injuries Soft tissue injuries are much more common than bony. Posterior Capsulolabral Repair : repair of the soft tissue posterior bony Bankart lesion, often combined with a capsular shift. Capsular Shift: A posterior capsular shift may be required for a hyperlax posterior capsule in the absence of a labral injury

41. posterior instability Surgery Bony Injuries Bony abnormalities are rare, but should always be considered, especially in patients with failed soft tissue surgery Subscapularis Transfer : McLaughlin procedure - transfer of the subscapularis tendon to the reverse Hill-Sachs defect Glenoid Osteotomy: a glenoid retroversion of above 20 degrees should be considered for glenoid osteotomy. Posterior Bone Block: This procedure is only considered in extreme cases as a bony block to posterior translation of the humeral head. High failure rates

42. arthroscopic repair Lower morbidity Easily assess the entire joint and treat associated pathology SLAP lesion, Rotator Interval lesions and anterior labral injuries Easier revision

43. arthroscopic repair Arthroscopic instability repair is considered a technically difficult operation How to make it easier ? Follow always standard steps

44. Arthroscopic repair of posterior instability Arthroscopic repair of posterior dislocation although rare is not so difficult The only think needed is just to reverse the portals

45. EXAMINATION UNDER ANESTHESIA You must have a feel of the joint

46. arthroscopic repair Anesthesia Patient positioning Surgeons Position Portals Haemostasis Instrumentation Suture management

47. ARTHROSCOPIC MANAGEMENT

48. ARTHROSCOPIC MANAGEMENT Anchor placement

49. ARTHROSCOPIC MANAGEMENT Knot tying

50. ARTHROSCOPIC MANAGEMENT Knot tying

51. ARTHROSCOPIC MANAGEMENT

52. ARTHROSCOPIC MANAGEMENT

53. 3 months post-op

54. 3 months post-op

55. 3 months post-op

56. 3 months post-op

57. 3 months post-op

58. REHABILITATION

59. conclusion Unidirectional posterior shoulder instability Is much less common than anterior instability It should be strongly suspected in those high risk group of athletes with posterior shoulder pain and/or clicking The treatment involves a combination of skilled therapy and surgery for optimal outcome

60. www.shoulder.gr Thank you! For your attention