Spinal Exam 3 (10. Sacrum an Pelvis)

Forms link between spine and iliac bones

Large inverted triangle shaped bone composed of 5 fused segments

Sacrum

The sacrum is wider at the base than at the

Apex

The sacrum is wider from left to right than

Front to bakc

Base

Apex

Auricular surfaces

Anterior surface

Posterior surface

Surfaces of sacrum

Body of __ is the base of sacrum

S1

Body of s1 is the ___ of the sacrum

Base

Features of the ____ of the sacrum

Sacral promontory

Sacral algae

Sacral cal

Superior articular process

Base

Projection of S1 body (anterior lip)

Sacral promontory

Wings or lateral sacral masses on the sacrum

Sacral alae

The superior articular process of the sacrum articulates with ____

L5

Superior articular process of sacrum articulating with L5

Lumbosacral joint

What surface of the sacrum is the lumbosacral joint?

Base of sacrum

Lumbosacral joint is brought together by __ joints

3 joints

Joints making up the lumbosacral joint

1 intervertebral joint

2 z joints

Formed by the triangular sacral vertebral foramina, opens out the sacral hiatus

Sacral canal

Lower end of cauda equina

Folium terminale

Spinal meninges

Extradural fat

Contents of sacral canal

Sacral and lumbar roots of spinal nerves L2-S5, below the end of the spinal cord

Cauda equina

Sections of the filum terminale

Internum and externum

Parts of the dural space

Dura mater, arachnoid mater, pita mater

Dural sac ends at

S2

Spinal cord ends at

L1-L2

Runs from cauda equina to coccyx

Filum terminale

filum terminale internum stretches from

L1/l2 to s2

Filum terminale externum

S2 to coccyx

Internum and externum filum terminale are found within

Sacral canal

Concave surface, faces down and forward, smooth compared to posterior surface, "pelvic surface"

Anterior sacrum

Anterior rami of spinal nerves form

Somatic plexus

Fused intervetebral discs

Fusion of bones of sacral vertebrae

Transverse ridges

Transverse ridges are found on what surface of sacrum

Anterior surface

4 pairs, 8 individual

Analogous to IVF

Antieror rami of S1-S4 spinal nerves exit the anterior sacral foramina

Anterior sacral foramina

Dorsal surface

Convex with significant amount of landmarks

Rougher compared to anterior surface

Posterior surface

Intermingling of nerves or blood vessels

Plexus

Anterior rami of s1-s4 of spinal nerves come together to make the

Sacral plexus

The sacral plexus is make up of

Anterior rami of s1-s4 spinal nerves

The sacral plexus exits via

Anterior sacral foramina

All of the following are found on the __ sacrum

Median sacral crest

Articular/intermediate sacral crest/medial sacral crest

Lateral sacral crest

Posterior

Fusion of s1-s4 sacral spinous process

Median sacral crest

Fusion of sacral articular processes

Intermediate sacral crest

Fusion os sacral TVPs

Lateral sacral crest

Lateral aspect of last 2 segments in sacrum

Lower portion of sacrum which curves medically, the Chang elf direction

Inferior lateral angle

Located on the posterior sacrum, lateral to median sacral grooves

Posterior sacrum

Remnants of interior articular processes of S5

Sacral cornua

Contains posterior rami of spinal nerves s1-s4

Posterior sacral foramina

Inferior opening of sacral canal

Absence of lamia of s5 exposing dorsal surface

Natural defect

Sacral hiatus

Contents of the ___ ____

Coccygeal nerve

Pair of 5th sacral spinal nerves

Filum terminale (externum)

Fat

Sacral hiatus

The 1st coccygeal spinal nerve goes through the

Sacral hiatus

Each lateral surface of a sacrum is made up of two parts:

Auricular surface

Sacral tuberosity

Forms the sacroiliac joint

Lined with hyaline cartilage

Articular surface

Rough prominence on the lateral surface of the sacrum

Posterior to auricular surface

Sacral tuberosity

The ilium is lined with what type of cartilage

Fibrocartilage

Sacrum is lined with what type of cartilage

Hyaline cartilage

Sacral vertebrae consists of 5 fused verebrae, fully fused by what age

30

Articulations of sacrum

Sacroiliac joint

Lumbosacral joint

Sacrococcygeal joint

Synovial non axial joint, gliding movements describes what articulation of the sacrum

Sacroiliac joint

A symphysis joint

Synoival, planar, and z joints

Describes what articulation of sacrum

Lumbosacral joint

The sacrococcygeal joint is what type of joint

Symphysis

Inverted L or C shaped articular surface, very small surface area

Hyaline cartilage on sacral side

Fibrocartilage on iliac side

Articular capsule on anterior surface

Si joint

Nerves supply to the si joint is from

Dorsal rami S1 and S2

The Si joint may be responsible for up to __ of all low back pain

50%

Si joins moves about ____mm or ___ degrees of motion

2 mm or 2 degrees

All movement of the si joint becomes a problem when it becomes

Fixed

Joints often become ___ with age and may completely ossify

Fibrous

The si joint is more flexible in

Young people and females

The si joint is more stiff in

Older people

More si problems are found in —— rather than _____

Females rather than males

A ring formed via hip joints, sacrum, and coccyx

Pelvic girdle

Transferees body weight from upper limbs to lower limbs

Attached lower limbs to axial Skeleton

Attachment for many muscles and ligaments, supporting joints relating to related

Functions of pelvic girdle

Anterior LS joint

Coral joint

Si joints

Symphsis Pubis and sacrococcygeal

5 joints of pelvic girdle

Number of TOTAl joints in the pelvic girdle

9

Convert pelvic girdle into resilient accomodating receptacle to ease locomotion

Allows weight bearing and shock absorption during load transfer from upper to lower limbs

Function of SI Joint

Type of movement of the ileum with regards to the sacrum

Si joint - 2mm

Non axial movement

Figure 8 motion

Main ligaments of the si joint

Anterior si ligament

Posterior si ligament

Accessory ligaments of the si joint

Sacrotuberous ligament

Sacrospinous ligament

Iliolumbar ligaments

Mainly thin strands forming a strong, broad, and flat brand

A thickening of anterior inferior ascpet of joint capsule

Capsule is thin

Anterior si ligament

The anterior si ligament extends from the __ to the ___

Ala of ilium to anterior lateral aspect of sacrum

Ligament that reinforces superior and posterior aspect of si joint

Posterior si ligament

3 bands of posterior sacroiliac ligament

Interoosesous si ligament

Short posterior si ligament

Long posterior sacroiliac ligament

Short but strong band that extends from the iliac tubersoity to the sacral tuberosity

Deepest, strongest of the main si ligaments

Interosseous si ligament

Si ligament that fills upper gap between ilium and sacrum

Extends between 1st and 2nd transverse tubercles of sacrum to iliac tuberosity

Superficial to interosseous si ligament

Short posterior si ligament

The short posterior si ligament extends between ____ to ____

1st and 2nd transverse tubercles of lateral sacral crest to iliac tuberosity

The short posterior si ligament is superificial to what ligament

Interosseous ligament

Extends from the psisi to the 3rd and 4th transverse tubercles of lateral sacral crest

Most superficial of the main ligaments

Blend inferiority with sacrotuberous ligament

Limits counternutation

Long posterior si ligament

The long posterior si ligament extends from __ to __

Psis to 3rd to 4th transverse tubercles of lateral sacral crest

Ligaments that prevent forward tilting of sacral promontory

Sacrotuberous ligament

Sacrospinous ligament

Triangular shape

Superficial to posterior sacroiliac ligaments

Extends from psis, posterior lateral sacrum and coccyx and insets on to the ischial tuberosity

Sacrotuberous si ligament

The Sacrotuberous si ligament extends from (3) and insets on ___

Psis, posterior lateral sacrum and coccyx, and inserts on to ischial tuberosity

Anterior to the Sacrotuberous ligament

Extends from lower anterior-lateral sacrum and coccyx to ischial spine

Sacrospinous si ligament

The sacrospinous ligament extends from (2) and inserts on ___

Lower anterior lateral sacrum and coccyx to ischial spine

Nutation and counternutation occur in what plane

Frontal plane

Which si ligament restricts nutation

Sacrotuberous si ligament

Forward movement of the sacral base with relationship to the ilium

Ilium comes together in posterior and widens in front

Sacrum moves anterior and inferior, coccyx moves posterior relative to ilium

Nutation

In nutation the sacrum moves ___ while the coccyx moves ___ in relation to the ilium

Anterior and inferior

Posterior

Sacral base moves posterior in relation to the ilium

Ilium opens in back and comes together in the front

Body response: lifting joint up against gravity

Sacrum moves up and back

Motion opposed primarily by long posterior si ligament

Counternutation

Counternutation is opposed primarily by

Long posterior si ligament

Sacrum is narrower but longer

More vertical

Less curved

Lumbosacral angle decrease

Male sacrum

Sacrum is wider and shorter

More horizontal

Anterior surface more curved

Lumboscaral angle increased

Female sacrum

A risk factor for patellar subluxation

Angle increases as females have wider sacrum

Increased q angle

Triangular bone like sacrum

Terminal point of vertebral column

Coccyx

The coccyx consists of

apex, base, lateral surfaces projecting from Co 1

Largest of small articulate processes, articulated with sacral cornua

Coccygeal cornua