2 Complications in Shoulder Arthroscopy

Clayton Alexander and Uma Srikumaran

Summary

Arthroscopic shoulder surgery complications are considered rare occurrences. However, there have been reports in the literature of complication rates as high as 10.6%. It is imperative to evaluate the incidence, severity, and prevention of these complications to improve surgical outcomes. Common complications reported after arthroscopic shoulder surgery are peripheral nerve injury, infections, arthrofibrosis, and thromboembolic events. Careful patient selection, surgical diligence, and extensive knowledge of the shoulder anatomy can prevent these complications.

Shoulder arthroscopy – complications – nerve injury – arthrofibrosis – infection

2 Complications in Shoulder Arthroscopy

I. Incidence and patient risk factors

Arthroscopic shoulder complications are less prevalent than open shoulder procedures ¹
Complication rates following arthroscopic shoulder procedures range from 1.0 to 10.6%: ² , ⁷
1. Wide range due to definition of complications and length of follow-up.
Common complications include: ⁸
1. Arthrofibrosis/stiffness
2. Infections
3. Deep vein thrombosis/pulmonary embolism (DVT/PE)
4. Peripheral nerve injury.
Patient risk factors: ¹
1. Age > 80 years
2. Body mass index (BMI) > 35
3. Functionally dependent status
4. American Society of Anesthesiology > 2 (Class III or IV)
5. Congestive heart failure
6. History of disseminated cancer
7. Open wound at time of surgery.

II. Patient positioning

No proven difference in complication rates between lateral decubitus and beach chair positions. ⁸

Lateral decubitus (▶ Fig. 2.1 ):
1. Theoretical benefits:
  1. Increased visualization and access
  2. Lower risk of hypotension, bradycardia, and cerebral hypoperfusion.
    
    Fig. 2.1 (a, b) Patient is in the lateral decubitus position and the surgical arm is held in an abducted position. ⁸
2. Potential complications:
  1. Neuropraxia from arm traction (10–30%)
  2. Higher rate of thromboembolic events
  3. Increased risk of injury to axillary and musculocutaneous nerves when placing anteroinferior portal. ⁹
Beach chair (▶ Fig. 2.2 ):
1. Theoretical benefits:
  1. Better anatomic orientation
  2. Easier to convert to open procedure
  3. Regional anesthesia is better tolerated than with lateral positions
  4. Decreased risk of neuropathies
  5. Decreased surgical time.
2. Potential hypoperfusion complications:
  1. Cerebral hypoperfusion:
    - i. Can be reduced with use of regional anesthesia instead of general anesthesia.
  2. Neuropraxia from head and neck malpositioning. ¹⁰

III. Anatomy and nerve injury

Iatrogenic nerve injuries are common due to proximity of the standard portals to the nerves ⁸ and lack of awareness of anatomical variations of the nerves. ¹¹

Axillary nerve:
1. Distance of axillary nerve from: ⁸
  1. Coracoid process tip: 3.56 ± 0.51 cm (immediately before entering the quadrangular space)
  2. Posterolateral acromion: 7.46 ± 0.99 cm
    
    Fig. 2.2 Patient is in the beach chair position preoperatively. ⁸
  3. Deltoid insertion: 6.7 ± 0.47 cm
  4. Upper border of deltoid origin:
    - i. Anterior: 4.94 ± 0.8 6 cm
    - ii. Middle: 5.14 ± 0.90 cm
    - iii. Posterior: 5.44 ± 0.95 cm.
2. Axillary nerve comes closest to capsule at 5:30–6:30 o’clock positions on the glenoid with the closest distance measuring 10–25 mm away ¹²
3. Standard posterior portal placement is usually a minimum of 2–3 cm from the axillary nerve:
  1. Placement is also 2 cm medial and 2 cm inferior to the posterolateral corner of the acromion.
4. Lateral working portals placed in the “safe zone” (located within 3 cm of the lateral border of the acromion) avoid the axillary nerve
5. Anterior portals, particularly anteroinferior portals, are at greater risk of neurovascular injury than posterior portals:
  1. Increasing risk of axillary nerve injury with inferior placement
  2. Placement of anterior portal lateral to the coracoid through the rotator interval is safe.
6. Specific arthroscopic procedures at higher risk of axillary nerve injury:
  1. Glenohumeral capsular release:
    - i. Through anteroinferior or posteroinferior axillary pouch and recesses places the nerve at risk of injury.
  2. Thermal capsulorrhaphy
  3. Arthroscopic stabilization:
    - i. Capsulolabral sutures of anteroinferior band of the inferior glenohumeral ligament have particular risk
    - ii. Sutures placed within 1 cm of the anterior glenoid rim are relatively safe.
  4. Arthroscopic axillary nerve release
  5. Arthroscopic Latarjet:
    - i. Close proximity of surgical instruments to axillary nerves. ⁸
Musculocutaneous nerve:
1. At risk with anterior working portal (▶ Fig. 2.3 ):
  1. Standard placement of portal is midway between anterolateral corner of the acromion and coracoid
  2. More inferior or medial placement of portal increases chances of injury
  3. Less risk of injury with placement under direct visualization. ⁸
Suprascapular nerve:
1. Unique anatomy of nerve makes it susceptible to injury during various open and arthroscopic shoulder procedures: ⁸
  1. Transglenoid drilling for instability:
    - i. Anchors have shown to decrease this risk.
      
      Fig. 2.3 Anterior arthroscopic working portal is placed midway between the coracoid and anterolateral acromion. ⁸
  2. Aggressive mobilization of retracted rotator cuff tear:
    - i. Risk is minimized by staying within 2 cm of superior glenoid rim.
  3. Arthroscopic decompression of suprascapular and spinoglenoid notches increases the vulnerability of the nerve to injury
  4. Arthroscopic transglenoid Bankart repair: ¹³
    - i. Usually transient injuries.