Patient Positioning for Spinal Surgery

Youmans Chapter 27

Outline

• Equipment• Principles of positioning• Specific procedures

Equipment

Tables

Tables

• Operations in the supine position– anterior cervical procedures– anterior lumbar fusions in the distal lumbar spine

(L3-S1)• A lateral approach for thoracic, thoracolumbar,

and lumbar procedure• Thoracoabdominal and retroperitoneal flank

approaches, it is often helpful to place the level of pathology at the table break and flex the patient laterally.

Jackson spinal table

• Radiolucent• Greater length of

height• Full 360 clearance• Use of multiple pad

Head Holders

• Cutouts for the eyes and endotracheal tube are the main safety features

• Other – Bean bag : lateral position for thoracotomy or

retroperitoneum flank approach– Armrests– Foam pad– Disposable heating blanket

Principles of positioning

• Surgical access : allow the surgeon to achieve the surgeon objective

• Patient safety and Protection – Neuropathies and prevention– Soft tissue injuries– Head Positioning– Visual loss and Its prevention– Air embolism

• Spinal alignment• Surgeon Ergonomics

Neuropathies and prevention• Ulnar neuropathy : most common postoperative

neuropathies• it is thought to be related to intraneural capillary

ischemia resulting from nerve overstretch or compression, perhaps exacerbated by prolonged intraoperative hypotension

• Time of onset of ulnar nerve symptom : after surgery to 3 day postoperative

• Duration : day to year• Risk factor : diabete, old age, male gender

Neuropathies and prevention• Superficial condyle

groove • Elbow flexion>110• External

compression

Neuropathies and prevention• Supine position : direct

pressure on ulnar n. at the elbow is significantly higher if both arm are pronated than if they are neutral position and supinate

Neuropathies and prevention

• Brachial plexus neuropathy : shoulder pain, scapular winging, and shoulder weakness

• Incidence during posterior spinal surgery : 3.6-15 %

• Duration : persistent at late 1-3 yrs • Upper trunk in supine position• Lower trunk in prone position• Pt congenital anomaly : cervical rib, shoulder

contracture

Neuropathies and prevention

• Somatosensory evoked potential (SSEP) monitoring as a way to detect impending nerve injury

• Lower extremity neuropathies : common peroneal n. injury(superficial location as it transverse the head of fibula)

Neuropathies and prevention

• Peroneal neuropathy : complete plegia of dorsiflexion and eversion without significant pain complain

• L5 radiculopathy : dermatomal pain, sensory deficit, weakness of dorsiflexion, toe extension, and foot inversion

Soft tissue injuries

• Prolong pressure leads to local ischemia, tissue necrosis

• Not bear significant structure• No EKG leads, IV line connector on supporting

pad• Lateral or prone position : abdomen should be

free as possible decrease intra-abdominal pressure, decrease pressure in the valveless epidural venous plexus (reduce epidural bleeding)

Head Positioning

• Neutral positioning for cervical region• Lateral and supine : soft support (doughbut-

shape foam or gel pad or pillow)• Rigid head holding• May-field system• Traction

Visual loss and Its prevention

• POVL : post operative visual loss• Most common cause : ischemic optic neuropathy

from compromised blood flow(increase venous pressure and interstitial edema), unilateral more than bilateral, prone position

• May be attribute to central renal artery occlusion• Associated with prolong anesthetic

operation(>6hr), significant blood loss(>1 lit)

Air embolism• Sitting position,Cervical osteotomies• Operative field above the heart air may be entrained

into open uncoaulated venous channel air embolism

• Precordial Doppler probe for diagnose an air embolism• Long venous line used in attempt to aspirate air• If air embolism is suspected during surgery : the field

should be flooded with sterile irrigation and position change to bring the head close to the level of heart

Spinal alignment• For procedure with no arthrodesis is performed :

lumbar microdiskectomy or cervical foraminotomy : optimized to facilitate safe, thorough neural decompression

Spinal alignment• Occipitocervical alignment

– improper positioning can lead to ovely extending and inability of patient to see their body

– excessive flexion or retraction can make swallowing difficult

– coronal or axial will require patient to compensate for head tilt or rotation to maintain level, forward gaze

Spinal alignment

• Lumbar decompressive : lumbar flexion create

• This position would not be used if an arthrodesis were also to be performed

• Hipextension enhances lumbar lordosis, thereby resulting in optimal spinal alignment for instrumented arthrodesis

Surgeon ergonomic

• Optomize the working environment for surgeon• Operative field heigt should be comfortable for

surgeon• Horizontal plane as possible• Lower cervical or cervicothoracic : reverse

trendelenberg• Operating microscope

Specific procedure

• Anterior cervical• Posterior occipitocervical, cervical,

cervicothoracic• Posterior Thoracolumbar Arthrodesis• Anterolateral, Retropleural Thoracic, Lateral

lumbar• Anterior lumbar• Intraoperative Repositioning

Anterior cervical• Maintain gentle cervical extension(lordosis), maintain head

and cervical spine are neutrally aligned in the axial plane• Hypoextension: kyphosis• Hyperextension : cervical spinal stenosis, neurological risk

intraoperative• Small padded roll is placed underneath the patient and

extended transversely to about the T2 level,• Foam doughnut is placed under the occiput• Paper tape extending from one side to the other and

adherent to the forehead is adequate to maintain neutral alignment

Posterior occipitocervical, cervical, cervicothoracic

• First, unobstructed anteroposterior and lateral radiographs or fluoroscopy can be obtained

• Second, the tabletop can be set up in a moderate reverse Trendelenburg position without raising the head unit

• Third, the modular pads can accommodate a wide variety of body types.

• Finally, the dual-vector traction is easily set up and manipulated.

Posterior Thoracolumbar Arthrodesis

• Position to maintain or enhance lumbar lordosis• All contact point,particulary the knees, are

padded carefully• It is also important to flex the knees and to

ensure that the feet are in a relaxed,neutral position and not in forced plantar flexion

Anterolateral, lateral lumbar Retropleural Thoracic,

• Lateral positioning follow the same principle as for the common anterior and posterior approach

• Soft tissue or pheripheral n. injury secondary to focal pressure

• Dependent axilla : soft roll to prevent excessive shoulder abduction

• Dependent arm : externally rotate, elbox flex 90, upper part gently flex, pillow

• Dependent leg : flex hip, flex knee

Anterior lumbar

• The arm may be abductes to allow access for anesthesiologist

• Heel support

Intraoperative repositioning

• Supine to prone, prone to supine• Two standard electric operating table