Complications associated with prone positioning in elective spinal surgery

Table 1 Positioning complications and risk factors

Complication	Risk factors
Ophthalmological complications
ION[14]	Obesity, male sex, Wilson frame use, longer anesthetic duration, greater estimated blood loss, increased ratio of crystalloid to colloid
Posterior ION[13]	Blood loss greater than 4 L, persistent relative hypotension
Anterior ION[16]	Atherosclerosis, diabetes
Central retinal artery occlusion[5,13]	External compression of the eye
Cortical blindness[13]	Profound hypotension, prolonged hypoxia, cardiac arrest, thromboembolism
Neurologic complications
Acute cervical myelopathy[20]	Cervical spondylosis, neck extension, paralytic anesthesia
Brachial plexopathy[21]	Extension, external rotation, and abduction of the arm, ipsilateral rotation and lateral flexion of neck, shoulder braces
Ulnar nerve palsy[30]	Obesity, inadequate elbow padding
Myocutaneous complications
Compartment syndrome[34-36]	Padding directly over the compartment, obesity
Pressure ulcers[37,38]	Procedure duration, advanced age, obesity, steroid administration
Femoral head avascular necrosis[42]	Pressure over the groin, hypotension

ION: Ischemic optic neuropathy.

Table 2 Strategies for minimizing risk during prone surgical procedures

Complication	Avoidance strategy
Ophthalmological complications
ION[14]	Reverse trendelenburg positioning, colloid administration by anesthesia, limit prolonged intraoperative hypotension
Posterior ION[13]	Limit prolonged intraoperative hypotension
Anterior ION[16]	None
Central retinal artery occlusion[5,13]	Avoid compression of the globe
Cortical blindness[13]	Limit prolonged intraoperative hypotension
Neurologic complications
Acute cervical myelopathy[20]	Thorough history and preoperative imaging, careful neck positioning during patient transfers and surgical procedure
Brachial plexopathy[21]	Careful anatomic positioning of the arm, limiting extension and external rotation of shoulder
Ulnar nerve palsy[30]	Avoid compression and pressure at the elbow, maintain arm position during procedure (avoid arm falling off of arm board)
Myocutaneous complications
Compartment syndrome[34-36]	Avoid pressure on anterior thigh and leg, avoid extremely long surgical procedures. Extra care with obese patients
Pressure ulcers[37,38]	Pad bony prominences. Consider Garner-Wells tongs to eliminate pressure on the face during lengthy procedures
Femoral head avascular necrosis[42]	Avoid pressure directly over the groin

ION: Ischemic optic neuropathy.