STEP ONE: Place patient in lateral position (Fig. 33.2). Place axillary roll, pad down leg and between legs, and flex both hips to relax psoas muscle (both hips flexed prevents pelvis from falling anterior), bend knees to prevent leg falling. Pad under down leg, especially peroneal nerve at fibular head. Position patient so that break in table is at top of iliac crest (Fig. 33.3).

Use hip grips to stabilize patient (Fig. 33.4): one posterior at chest and one anterior at chest. Position patient 4 in from posterior edge of table. This allows subtle adjustment in tilting bed to correct rotation. If the bed is tilted too much posterior, then the metal bar on the side of the table can block the X-ray view. If the bed is tilted too much anterior, then the surgeon will be bent over too far to do the surgery.

Know your table. You want to position the patient posterior enough on table so you don’t have to lean over, but if you need to tilt the bed to correct rotation on AP view, does the table have radiodense bars that will obstruct your X-ray?

STEP TWO: Check AP X-ray for rotation. Correct rotation now, before final taping and breaking of bed. Once patient is taped to the bed, you can make subtle adjustments by tilting the bed, but you don’t want to tilt the bed too much and encounter the problems described above. If operating on multiple scoliotic levels, tape the patient to the bed with the middle operative disc in neutral on the AP X-ray. Make subtle tilts in the bed to neutralize the other discs when specifically working on them.

STEP THREE: Tape the patient to the bed. Secure patient to the bed with 6-in elastic tape (Tensoplast/Elastoplast) (Fig. 33.5). Use one complete roll circumferentially around the bed and patient for the iliac crest and one for the rib cage. Don’t worry if the tape interferes with the surgical site, it can be rolled back off the skin.

Tape the legs across thigh and across lower leg to hold hips and knees flexed with silk tape.

STEP FOUR: Break the bed (Fig. 33.6). Generally, break the bed 50 % of the maximum allowed. Breaking the bed too much puts tension on the psoas and lumbar plexus, and closes down the contralateral side of the disc. Breaking the bed too little doesn’t move the ribs and iliac crest apart to open the surgical site. At L4–L5, break the bed enough to get the iliac crest out of the way. Generally, if the iliac crest crosses the L4–L5 disc, by taping the crest to the bed and breaking the bed, access to the disc should be possible. If the crest crosses the middle of the L4 vertebral body, then access is still possible but probably will be difficult. A bump may be placed to help position the iliac crest out of the path of the retractor and deliver the L4–L5 disc space (Fig. 33.7). As well, part of the iliac crest may be removed (and used for bone graft) if it is blocking access to the L4–L5 disc.

STEP FIVE (Fig. 33.8): After breaking the bed re–secure the legs so that hips and knees flexed (gravity may cause them to drop down).

STEP SIX: Check AP X-ray for rotation (Fig. 33.9)—tilt bed for subtle corrections.

STEP SEVEN: Check lateral X-ray (Fig. 33.10). (1) Adjust trendelenburg in order to make operative disc perpendicular to floor and parallel to X-ray beam in neutral position. (2) Mark line on skin parallel to disc space (place several centimeters superior or inferior to disc so that it does not interfere with mark for skin incision). Line shows angle of disc based on lordosis/kyphosis. When the X-ray tech moves imager to AP view, the wig wag should be adjusted to make the X-ray beam parallel to this line. This provides the best Ferguson view and makes the endplates most clear on the AP view. This is the only adjustment the X-ray tech makes: everything should be 0–90°, except in the AP view make the X-ray beam in line with the angle of the disc.