Lumbar Spine

• large, bean shaped bodies

• smaller transverse processes

• pedicles project posteriorly

• large, thick, blunt spinous processes

• also have a pars intetarticularis, mammillary process, and accessory process

typical lumbar vertebrae

• part of lamina btw sup/inf articular process

• seen on obliques

pars interarticularis

smooth rounded projection on posterolateral portion of sup art. process

mammillary process

accessory process

small bump at base of transverse process

30-60°

zygapophyseal joints are inclined post. from coronal plane and open post. __________ degrees from MSP. Angle increases from L1 through L5-S1

90

IVF open ______ degrees

upside

RAO is shown with ______ zygapophyseal joints open

base

_____ of sacrum directed superiorly and anteriorly

apex

directed post. and inferiorly

• ala

• sacral promontory

• sacral foramina

anterior parts of sacrum

winglike mass at each side of base

ala

superior anterior margin of S1

sacral promontory

4 pairs; thru anterior and posterior walls of the sacral canal (passage of nerves and vessels)

sacral foramina

• superior articular process

• sacral canal

• auricular surface

• median sacral crest

• sacral hiatus

posterior side of sacrum

superior articular process

articulates w/ L5

sacral canal

superior opening

auricular surface

upper lateral surface of ala; 25-30° posterior angle

sacral hiatus

inferior opening

sacral cornu

2 processes projecting inferiorly from last segment

coccygeal cornu

project posteriorly from posterolateral aspect of 1 segment

iliac crest

L4 is equal with what external landmark?

lumbosacral- enters MSP at level of iliac crest (L4) (lumbar - 1.5’’ above crest)

CR for AP Lumbosacral spine

lumbosacral- perp to IR at MCP & iliac crest (L4) (lumbar - 1.5’’ above crest)

CR for lateral lumbosacral spine

perp to IR (with support) entering 1 ½’’ inferior to iliac crest & 2’’ post to ASIS

CR for Lateral L5-S1 (conedown)

2’’ medial to elevated ASIS & 1- 1 1/2’’ above crest (L3)

CR for AP oblique L spine

• thru lumbosacral joint at 30° (male) - 35° (female) cephalad

• 2 to 2 ½’’ below ASIS

CR for AP axial lumbosacral joint or SI joints

perp 1’’ medial to upside ASIS

CR for posterior (LPO/RPO) oblique SI joints

15° cephalad 2’’ superior to pubic symphesis

CR for AP axial sacrum

10° caudad 2’’ superior to pubic symphesis

CR for AP axial coccyx

perp at 3 to 3 1/2’’ posterior to ASIS

CR for lateral sacrum AND coccyx