Quiz 2- Lec 7-8 Flashcards
Joints and Ligaments of Pelvis
lumbosacral junction: joint type
anteriorly: 2º cartilaginous joint “symphysis”
posteriorly: zygapophyseal joint
how is lumbosacral junction similar/different from other joints of the spine?
similar to other joints of the spine/vertebral column in terms of basic parts
UNIQUE in that the sacral base and the disc between L5/S1 are tilted forward off the horizontal by 30 degrees, (sacral inclination)
![](https://s3.amazonaws.com/brainscape-prod/system/cm/264/728/844/a_image_thumb.png?1547408590)
sacral inclination: what is is, how much, and M/F
angle between sacral base& disc from the horizontal;
usually about 30 degrees
Females (sacral inclination) > male
typical lumbosacral angle (value)
140 degrees
effects of increased lumbar LORDOSIS on the:
- sacral inclination and,
- lumbosacral angle
In increase in lumbar LORDOSIS, the
- sacral inclination: increases
- lumbosacral angle: decreases
![](https://s3.amazonaws.com/brainscape-prod/system/cm/264/729/208/a_image_thumb.png?1547408932)
movements and plantes at LUMBOSACRAL JOINT
(4 pairs)
- Flexion (lmtd)/extension - Sagittal plane
- Some side-bending - Coronal/frontal plane
- Some rotation - horizontal plane
- *side-bending cannot occur w/o rotation (& vice versa) - called joint coupling
Why can flexion (lmtd)/extension at the LUMBOSACRAL joint occur in the Sagittal plane?
bc inferior articular facts of L5 are not oriented in sagittal plane –> rather, they are oriented in frontal/coronal plane
Why is there some side-bending at the LUMBOSACRAL joint in the Coronal/frontal plane?
due to facets being oriented in CORONAL plane –> so less flexion
sacroiliac joint: articulation and function
articulation between axial and appendicular skeleton
fxn: the upper body weight above the pelvis is transferred across the SI joint to the lower limbs
![](https://s3.amazonaws.com/brainscape-prod/system/cm/264/731/891/a_image_thumb.png?1547410531)
Sacroiliac joint: classification and movement
classification: plane synovial joint (articulation between auricular surfaces of sacrum & ilium) and syndesmosis (b/w sacral & iliac tuberosities)
*very little movement occurs here (atypical for synovial joints)
![](https://s3.amazonaws.com/brainscape-prod/system/cm/264/732/140/a_image_thumb.png?1547410628)
what are the adaptations that the Sacroiliac joint developed? what is the purpose?
Adaptations:
- rough interlocking articular surfaces (sacral cartilage is hyaline; iliac cartilage is fibrous
- interosseous ligaments (part of syndesmosis)
- accessory ligaments
Purpose: to LIMIT MOVEMENT and FACILITATE WEIGHT TRANSFER
![](https://s3.amazonaws.com/brainscape-prod/system/cm/264/732/829/a_image_thumb.png?1547410706)
what is the movement at the sacroiliac (SI) joint?
small amount of rotation (1-8º); some mvmt of sacrum, more in females/pregnancy
CC: what can occur to the SI (sacroiliac joint) in old age?
subject to degenerative changes
can become completely fused in old age
![](https://s3.amazonaws.com/brainscape-prod/system/cm/264/733/333/a_image_thumb.png?1547410790)
CC: what is fusion of the sacroiliac joint called?
anklyosis: when bony growth has obliterated the separation between ilium and sacrum
how do the interlocking auricular surfaces of the sacrum & iliac assist in the function of the SI joint?
- surfaces are virtually flat in infants –> become irregular (adulthood)
- reciprocal surface feat. consist of transverse oriented ridges and furrows (covered in cartilage) –> contributes to stability & strength of the joint in transmitting weight from the spine to the lower limbs –> limiting movement
![](https://s3.amazonaws.com/brainscape-prod/system/cm/264/733/393/a_image_thumb.png?1547411154)
where is the syndesmosis (fibrous) part of SI joint?
where is the synovial plant part of the SI joint?
![](https://s3.amazonaws.com/brainscape-prod/system/cm/264/734/083/q_image_thumb.png?1547411211)
![](https://s3.amazonaws.com/brainscape-prod/system/cm/264/734/083/a_image_thumb.png?1547411225)
what aspec of the ILIUM can help determine the age of a pelvis?
the ridges and furrous of the AURICULAR surface of the ILIUM undergoes age-related changes
sacroiliac fibrous joint capsule: anterior composition
comprised of bands of capsular ligaments (thickenings of fibrous capsule)
ventral sacroiliac ligament: attachments
medial: at base and pelvic surfaces of sacral segments S1-S3
lateral: to medial edge of the iliac fossa (thick at arcuate line and preauricular sulcus)
![](https://s3.amazonaws.com/brainscape-prod/system/cm/264/734/721/a_image_thumb.png?1547411423)
interosseous sacroiliac ligament: attachments
- medial: at sacral tuberosity
- lateral: at iliac tuberosity
- (may develop from dorsal part of fibrous capsule)
- *STRONGEST LINK BETWEEN ILIUM AND SACROM; abundant fibers
![](https://s3.amazonaws.com/brainscape-prod/system/cm/264/734/781/a_image_thumb.png?1547411503)
extracapsular ligaments include SHORT and LONG DORSAL SACROILIAC LIGAMENTS:
location
posterior to interosseous sacroiliac ligament
SHORT dorsal sacroiliac ligament: attachments
nearly horizontal in direction (Seen in red)
- sacral base and prox. 1/2 of intermediate sacral crest
- iliac tuberosity
![](https://s3.amazonaws.com/brainscape-prod/system/cm/264/735/840/a_image_thumb.png?1547411774)
LONG dorsal sacroiliac ligament: attachments
- oblique in direction;
- it is attached by one extremity to the lateral sacral crest (S3/S4)
- the other to the posterior superior spine of the ilium (PSIS).
![](https://s3.amazonaws.com/brainscape-prod/system/cm/264/738/523/a_image_thumb.png?1547411839)
list the ACCRSSORY ligaments of the SI joint
- Iliolumbar ligament
- Sacrotuberous
- Sacrospinous ligament
iliolumbar ligament:
type of ligament, attachments
- accessory ligament of SI joint
- series of bands from L4/L5 body & transverse process to
- iliac crest, iliac tuberosity, upper surface of sacral ALA, and ventral sacroiliac ligament
![](https://s3.amazonaws.com/brainscape-prod/system/cm/264/738/786/a_image_thumb.png?1547412019)
sacrotuberous ligament:
type and attachments
- accessory ligament of SI joint
- from: medial edge of ischial tuberosity
- to: PSIS adn PIIS (and between), lateral sacral crest (S3-S5) & coccyx
Remember:
- PSIS: Posterior superior iliac spine*
- PIIS: posterior inferior iliac spine*
![](https://s3.amazonaws.com/brainscape-prod/system/cm/264/738/864/a_image_thumb.png?1547412797)
sacrospinous ligament:
type and attachments
deep to sacrotuberous lig
- from: ischial spine
- to: lateral edge of S4/S5 and coccyx
![](https://s3.amazonaws.com/brainscape-prod/system/cm/264/740/235/a_image_thumb.png?1547412786)