1. Speaker: R1 莊昌翰 Supervisor: VS 蘇維仁 2009/11/20 7A 日光室 Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 25, No 8 (August), 2009: pp 891-896 Concise Review Shoulder Arthroscopy Positioning: Lateral Decubitus Versus Beach Chair

2. Introduction  Shoulder arthroscopy  lateral decubitus / beach chair position  Ease ; efficiency ; economics of setup; the visualization of and access to the surgical site; risks to the patient

3. Lateral Decubitus

4. Beach Chair

5. Ease of Setup  Number of steps, amount of equipment, assistance required to set up and perform the arthroscopy  Lateral decubitus position  turn and secure the patient; hold the humerus in internal or external rotation during the surgery  Beach chair position  secure the head, neck, and torso; position the arm if a mechanical arm holder is not used  To date, no objective, empirical evidence to support either group ’ s claims of speed of setup or need for assistance.

6. Conversion  Beach chair  Open procedure without the need for repositioning and redraping, greater flexibility  The need from an arthroscopic to an open procedure is rare

7. Anesthesia  Beach chair  Regional anesthesia is possible  Beach chair  rapid conversion to general anesthesia

8. Cost of Setup  Beach chair  costly equipment  Arm positioners  expensive, assist in stabilizing the arm (add to the ease of the procedure, not an absolute necessity)

9. Orientation, Visualization, Accessibility  Beach chair  upright, anatomic position makes orientation and teaching easier  Beach chair  no difficulty visualizing and working in all portions of the glenohumeral joint and subacromial space  Beach chair  stabilize the scapula makes an examination under anesthesia easier  Beach chair  is the best position for anterior stabilization, releases, and rotator cuff repairs  Beach chair  access to the anterior shoulder  easier without the arm hanging in the operative field  Beach chair  the superior mobility of the arm  better dynamic view of the cuff pick up  subluxation and both internal and subacromial impingement

10. Orientation, Visualization, Accessibility  Beach chair  the table and the head act as mechanical blocks limiting workspace for the posterior and superior portals  decreased visibility because of fogging of the camera and the collection of bubbles in the subacromial space  Beach chair  visualization of the posteroinferior glenoid has been reported to be insufficient using an anterosuperior portal unless sufficient abduction and traction are applied to the arm

11. Orientation, Visualization, Accessibility  Lateral decubitus  better visualization and workspace, both in and around the shoulder  Lateral decubitus  traction is said to accentuate labral tears and improve access to the labrum, subacromial space, inferior capsule, and underside of the rotator cuff  Lateral decubitus  arthroscopic posterior Bankart repair and capsulorrhaphy is more easily performed

12. Orientation, Visualization, Accessibility  Lateral decubitus  positioning the glenoid parallel to the floor  standard reference point and turning the camera 90° aids in the conceptualization of the anatomy in the natural sitting position.

13. Orientation, Visualization, Accessibility

15. Risks ( Lateral decubitus position)  Neurovascular and cardiovascular risks  Traction  damage to peripheral nerves and the brachial plexus; paresthesias and palsies have a reported 10% to 30% incidence.  Soft tissue injuries and compression of digital nerves, compression of the peroneal nerve  Decreased limb perfusion, especially with the use of both vertical and longitudinal traction  The musculocutaneous and axillary nerves being at greatest risk

16. Risks (beach chair position)  Neurovascular injuries are less common  Compression and rotation of the head have been associated with 3 superficial nerve palsies and 1 hypoglossal nerve palsy  Profound hypotensive and bradycardic events have been reported in more than 20% of patients  Brain and spinal cord ischemia, transient visual loss, and opthalmoplegia caused by hypotension  Abdominal obesity  compression of the vena cava decreases venous return  hypotension in the upright position  Hyperextension and rotation or tilt of the head  decrease vertebral artery blood flow causing infarcts of the posterior cerebral circulation  Ischemic event caused by air embolus

17. To minimize the risks  Lateral decubitus  position and found that 45° of forward flexion combined with either 90° or 0° of abduction maximized visibility and minimized strain  No more than 15 to 20 pounds of traction are applied  minimize strain on the brachial plexus  Beach chair position  metoprolol can decrease the incidence of hypotensive and bradycardic events.  Avoid cardiovascular complications  placing the blood pressure cuff at the level of the heart rather than the calf / aggressively treating perioperative blood pressure values lower than 80% of preoperative resting values

18. CONCLUSIONS

19.  Significant difference in the cost of equipment for the beach chair position if the surgeon chooses to use the beach chair attachments and/or a mechanical arm positioner  The complications associated with each position are rare, avoidable, and they should be considered when choosing a patient position  The lateral decubitus position puts neurovascular structures at greater risk  The risk of cardiovascular complications is greater for patients in the beach chair position, and hypertension and obesity further increase those risks.  After considering the costs and risks, there is no argument that can be made against a surgeon choosing a position based on their experience and comfort.

20. Thank you for your attention!