Iliac crest
Encyclopedia
The crest of the ilium is the superior border of the wing of ilium
and the superolateral margin of the greater pelvis
.
(ASIS) to the posterior superior iliac spine
(PSIS). Behind the ASIS, it divides into an outer and inner lip separated by the intermediate zone. The outer lip bulges laterally into the iliac tubercle
.
Palpable
in its entire length, the crest is convex superiorly but is sinuously curved, being concave inward in front, concave outward behind.
It is thinner at the center than at the extremities.
, Obliquus externus abdominis, and Latissimus dorsi
, and along its whole length the fascia lata
; to the intermediate line the Obliquus internus abdominis.
To the internal lip, the iliac fascia
, the Transversus abdominis
, Quadratus lumborum
, Sacrospinalis, and Iliacus
.
, and thus it is the site of bone marrow harvests (from both sides) to collect the stem cells used in bone marrow transplantation. The iliac crest is also considered the most ideal donor site for bone grafting when a large quantity of bone is needed. For example, oral surgeons will often use iliac crest bone to fill in large osseous defects of the oral cavity caused from severe periodontal disease, excess bone resorption following tooth loss, or trauma
The top of the iliac crests also marks the level of the fourth lumbar vertebral body (L4), above or below which lumbar puncture
may be performed.
Wing of ilium
The wing of ilium is the large expanded portion which bounds the greater pelvis laterally. It presents for examination two surfaces—an external and an internal—a crest, and two borders—an anterior and a posterior.-External surface:...
and the superolateral margin of the greater pelvis
Greater pelvis
The greater pelvis is a portion of the cavity surrounded by the skeleton of the pelvis, situated above and in front of the pelvic brim...
.
Anatomy
The iliac crest stretches posteriorly from the anterior superior iliac spineAnterior superior iliac spine
The anterior superior iliac spine is an important landmark of surface anatomy. It refers to the anterior extremity of the iliac crest of the pelvis, which provides attachment for the inguinal ligament, and the sartorius muscle...
(ASIS) to the posterior superior iliac spine
Posterior superior iliac spine
The posterior border of the ala, shorter than the anterior, also presents two projections separated by a notch, the posterior superior iliac spine and the posterior inferior iliac spine. The posterior superior iliac spine serves for the attachment of the oblique portion of the posterior sacroiliac...
(PSIS). Behind the ASIS, it divides into an outer and inner lip separated by the intermediate zone. The outer lip bulges laterally into the iliac tubercle
Iliac tubercle
The iliac tubercle is located approximately posterior to the anterior superior iliac spine on the iliac crest in humans. The transverse plane that includes each of the tubercles is called the transtubercular plane. The origin of the iliotibial tract is the iliac tubercle...
.
Palpable
Palpation
Palpation is used as part of a physical examination in which an object is felt to determine its size, shape, firmness, or location...
in its entire length, the crest is convex superiorly but is sinuously curved, being concave inward in front, concave outward behind.
It is thinner at the center than at the extremities.
Muscles
To the external lip are attached the Tensor fasciae lataeTensor fasciae latae
The tensor fasciae latae or tensor fasciæ latæ is a muscle of the thigh. The English name for this muscle is the muscle that stretches the band on the side...
, Obliquus externus abdominis, and Latissimus dorsi
Latissimus dorsi muscle
The latissimus dorsi , meaning 'broadest muscle of the back' , is the larger, flat, dorso-lateral muscle on the trunk, posterior to the arm, and partly covered by the trapezius on its median dorsal region.The latissimus dorsi is responsible for extension,...
, and along its whole length the fascia lata
Fascia lata
-Thickness:It is an investment for the whole of the thigh, but varies in thickness in different parts.Thus, it is thicker in the upper and lateral part of the thigh, where it receives a fibrous expansion from the Glutæus maximus, and where the Tensor fasciæ latæ is inserted between its layers; it...
; to the intermediate line the Obliquus internus abdominis.
To the internal lip, the iliac fascia
Iliac fascia
The iliac fascia is a fascia in the pelvic area of the human body.It has the following connections:* laterally, to the whole length of the inner lip of the iliac crest....
, the Transversus abdominis
Transversus abdominis muscle
The transversus abdominis muscle, also known as the transverse abdominus, transversalis muscle and transverse abdominal muscle, is a muscle layer of the anterior and lateral abdominal wall which is deep to the internal oblique muscle...
, Quadratus lumborum
Quadratus lumborum muscle
The Quadratus lumborum is irregular and quadrilateral in shape, and broader below than above.-Origin and insertion:It arises by aponeurotic fibers from the iliolumbar ligament and the adjacent portion of the iliac crest for about 5 cm., and is inserted into the lower border of the last rib for...
, Sacrospinalis, and Iliacus
Iliacus muscle
The iliacus is a flat, triangular muscle which fills the iliac fossa.- Course :The iliacus arises from the iliac fossa on the interior side of the hip bone, and also from the region of the anterior inferior iliac spine...
.
- Abdominal external oblique muscleAbdominal external oblique muscleThe external oblique muscle is the largest and the most superficial of the three flat muscles of the lateral anterior abdomen.-Structure:...
- Abdominal internal oblique muscleAbdominal internal oblique muscleThe internal oblique muscle is the intermediate muscle of the abdomen, lying just underneath the external oblique and just above the transverse abdominal muscle.-Structure:...
- Transversus abdominis muscleTransversus abdominis muscleThe transversus abdominis muscle, also known as the transverse abdominus, transversalis muscle and transverse abdominal muscle, is a muscle layer of the anterior and lateral abdominal wall which is deep to the internal oblique muscle...
- Quadratus lumborum muscleQuadratus lumborum muscleThe Quadratus lumborum is irregular and quadrilateral in shape, and broader below than above.-Origin and insertion:It arises by aponeurotic fibers from the iliolumbar ligament and the adjacent portion of the iliac crest for about 5 cm., and is inserted into the lower border of the last rib for...
- Erector spinaeErector spinaeThe Erector spinæ is a muscle group of the back in humans and animals. It is also known as sacrospinalis in older texts. A more modern term is extensor spinae, though this is not in widespread use. The name of the muscle is pronounced e-rec-tor speen-aye, or e-rec-tor spinae-ee.It is really not...
- IliocostalisIliocostalisThe iliocostalis is the muscle immediately lateral to the longissimus that is the nearest to the furrow that separates the epaxial muscles from the hypaxial...
pars lumborum - LongissimusLongissimusThe longissimus is the muscle lateral to the semispinalis. It is the longest subdivision of the sacrospinalis that extends forward into the transverse processes of the posterior cervical vertebrae.-Longissimus thoracis:...
pars thoracis
- Iliocostalis
- Latissimus dorsi
- Tensor fasciae lataeTensor fasciae lataeThe tensor fasciae latae or tensor fasciæ latæ is a muscle of the thigh. The English name for this muscle is the muscle that stretches the band on the side...
- Iliacus muscleIliacus muscleThe iliacus is a flat, triangular muscle which fills the iliac fossa.- Course :The iliacus arises from the iliac fossa on the interior side of the hip bone, and also from the region of the anterior inferior iliac spine...
- Fascia lataFascia lata-Thickness:It is an investment for the whole of the thigh, but varies in thickness in different parts.Thus, it is thicker in the upper and lateral part of the thigh, where it receives a fibrous expansion from the Glutæus maximus, and where the Tensor fasciæ latæ is inserted between its layers; it...
- Iliac fasciaIliac fasciaThe iliac fascia is a fascia in the pelvic area of the human body.It has the following connections:* laterally, to the whole length of the inner lip of the iliac crest....
- Transverse fasciaTransversalis fasciaThe transversalis fascia is a thin aponeurotic membrane which lies between the inner surface of the Transversus abdominis and the extraperitoneal fascia....
Clinical significance
The iliac crest has a large amount of red bone marrowBone marrow
Bone marrow is the flexible tissue found in the interior of bones. In humans, bone marrow in large bones produces new blood cells. On average, bone marrow constitutes 4% of the total body mass of humans; in adults weighing 65 kg , bone marrow accounts for approximately 2.6 kg...
, and thus it is the site of bone marrow harvests (from both sides) to collect the stem cells used in bone marrow transplantation. The iliac crest is also considered the most ideal donor site for bone grafting when a large quantity of bone is needed. For example, oral surgeons will often use iliac crest bone to fill in large osseous defects of the oral cavity caused from severe periodontal disease, excess bone resorption following tooth loss, or trauma
The top of the iliac crests also marks the level of the fourth lumbar vertebral body (L4), above or below which lumbar puncture
Lumbar puncture
A lumbar puncture is a diagnostic and at times therapeutic procedure that is performed in order to collect a sample of cerebrospinal fluid for biochemical, microbiological, and cytological analysis, or very rarely as a treatment to relieve increased intracranial pressure.-Indications:The...
may be performed.
