Open lumbar spine surgery - Part I

Types of tables:

- Jackson with OSI frame: standard setup that we use - has table with the rails and the pads for chest, hips, thighs. can adjust level of rods at each end so you get extra T or reverse-T - if you're doing say an L5-S1 fusion and the sacral slope is really steep, you can get feet up so you're working horizontally, etc etc. When putting people on OSI, put chest pad on upper chest- not directly against chin, not too low for women. Some people think you should straighten knees relative to hips so you avoid hypothetical risk of fusing people in hip flexion position, however in real life this is rarely a problem.
- Jackson table with Wilson frame: forced flexion over the arc. Gets you better access to the disc, which is useful if you're doing a discectomy, however can give you a false sense of security about how much decompression you have achieved. Like you feel nerve roots, you think they are decompressed because they are in forced flexion, but then when back goes straight everything closes off and then you're not decompressed anymore. Also as a note - if you're gonna use a Wilson frame, better to do Jackson table because its' lower - Wilson frame is high, unless you're really tall you're gonna be on 4 steps.
- Jackson table w Axis frame - can bend in half. Most useful for XLIF/DLIF when you position patient laterally, really opens up space between iliac crest and and ribs.
- Jackson flattop - useful vs standard table because its radiolucent and also no giant pedicle in the middle- so if you're doing an ALIF you have an easier time getting C-arm under table.

Arm positioning :
- up for middle T/L - make sure no hyperextension of arms back or too anterior, keep elbows soft, 90 degrees; protect against axillary nerve injury
- down/wrapped for C and upper T

Setting up the room:
- head towards anesthesia, scrub nurse at legs, surgeon on each side of back.
- assuming the pathology doesn't have laterality, choose the side of patient that doesn't have the base of the C-arm on it, so you're not moving your steps/foot pedals around every time the C-arm moves.
- when you move c-arm out of the way, move it towards anesthesia/patient head - because your scrub nurse is by patient's legs and you don't want the c-arm between you

General principles
- Look at CT scan before every case; look at anatomy - planning on lami, make sure there is actually lamina at every level. Some people have big facets, and there may be no lamina to take at a given level, or some atypical scoliosis, such that you have to drill at an angle. if you meant to do a lami, without a fusion, and you violate the facet capsule or worse drill facet when you didn't mean to, then you're hosed because you've destabilized that level.
- determine pedicle sizes on scan, pick out screw size and length beforehand, write them on the board

Process:
- localize level first  with c-arm.
- mark incision
- prep and drape wide
- 15 blade through skin
- buzz through fat with impunity
- put finger in and feel for the spinous processes - directly above spinous process is fascia. every time. every time. that's where it is. lateral to spinous process will be bumps for paraspinous muscle.
- take cobb and scrape last bit of fat off fascia. In everyone except super old frail people with terrible fascia, you can scrape and you will not accidentally break through as long as you're not jabbing aggressively
- cut on either side of spinous process. Take cobb, put raytech on it, and scrape down along spinous process. you should be sub-periosteal. if you are not, you will be in muscle - it will bleed like crazy and the patient will have a lot more postop pain. alternative to cobb is bovie down bone (but be careful directly lateral to lamina- there lie nerve roots). problem with bovie is it will cause paraspinal muscles to tighten and fight you - option to ask anesthesia for short-acting muscle relaxant. if someone has pacemaker or otherwise can't tolerate electrocautery, then you have to do the bipolar and cut thing which sucks.
- your cobb will then land on lamina. scrape ROSTRAL and LATERAL - next you will land on a valley of bone which is the superior aspect of pars, between the superior facet and the lamina. then scrape your cobb more rostral and more lateral - you will go over a bump, this is the facet capsule, and then you will land on the transverse process. If you're only doing a lami, you don't need to see TP but if you're doing a fusion you will need to expose a lot of the TP.
- THE PEDICLE IS ROSTRAL TO THE SPINOUS PROCESS. once you find the spinous process, you have to go rostral to find pedicle. this is especially true in thoracic spine - if you try to take shortcuts and aren't thoughtful, and you go for the pedicle directly next to the spinous process, you will put the screw in the wrong level.
- the anatomy is as such: from rostral to caudal  superior facet, TP/pedicle, lamina, inferior facet, with the pars representing the bridge of bone connecting superior to inferior facet

NB
- if you're doing a lami, you cannot drill all the way lateral - if you take pars, you destabilize
- you cannot bovie with impunity directly lateral to the spinous process/lamina - that's where the nerve roots come out. (if patient jumps and they are not paralyzed, its because your electrocautery hit a nerve root). this is why we don't paralyze spine cases.
- there is often a large artery next to pars - if it starts bleeding like crazy, don't dive after it with electrocautery, as you might hit nerve roots.
- if someone has giant, super hypertrophied facets, you might need to drill off the inferior aspect of facet to access entry point for pedicle screw - be careful - you can only drill approx 1/3 of facet joint before you destabilize

Thoughts on cervical decompression
- if most of someone's compression is coming from disk, you can do ACDF
- if there is a hypertrophied ligamentum flavum or facet arthropathy, you can get a lot more decompression of spinal cord if you come from the back