BONE

INTRODUCTION

  • This academic notes from Can Tho University of Medicine and Pharmacy focuses on the anatomy of the lower limb bones.

  • Key themes include the understanding of bone and joint importance, the names, locations, and landmarks of lower limb bones, and implications for diagnosing musculoskeletal diseases.

TARGETS

  • Understand the importance of bones and joints of the lower limb.

  • Name and locate the bones of the lower extremities.

  • Describe the landmarks of the lower extremities.

  • Describe the joints of the lower extremities, including hip joints, knee joints, etc.

  • Apply knowledge to diagnose musculoskeletal diseases of the lower extremities, such as fractures, dislocations, and ligament injuries (ACL, PCL).

HIP BONE ANATOMY

THE ILIUM (ILIAC BONE)

  • The ilium is the largest of the three bones forming the hip bone, with the other two being the ischium and pubis.

  • Characterized by its large, fan-like shape, it is located along the superolateral aspect of the pelvic girdle.

  • Parts:
      - Body
      - Ala (wing)

  • Surfaces:
      - Gluteal surface
      - Sacropelvic surface
      - Anterior, posterior, and medial borders
      - Iliac fossa

  • Landmarks:
      - Anterior superior iliac spine (ASIS)
      - Anterior inferior iliac spine (AIIS)
      - Posterior superior iliac spine (PSIS)
      - Posterior inferior iliac spine (PIIS)
      - Anterior, posterior, and inferior gluteal lines
      - Iliac tubercle

LOCATION AND ARTICULATIONS OF ILIUM

  • The ilium is: Proximal to the femur; Superior to the ischium & pubis; Lateral to the sacrum and fifth lumbar vertebra.

  • Articulates with:
      - Ischium and pubis
      - Sacrum at the sacroiliac joint
      - Femur at the hip joint

THE PUBIS

  • Known as the pubic bone, it is the smallest of the three bones that form the hip bone.

  • Characterized by its thick and irregular shape, the pubis is found along the anteroinferior aspect of the pelvic girdle.

  • Parts:
      - Body
      - Superior pubic ramus
      - Inferior pubic ramus

  • Surfaces:
      - Anterior, posterior, and symphyseal surfaces of body
      - Pectineal surface, obturator surface
      - Pelvic surface of superior pubic ramus

  • Landmarks:
      - Obturator groove
      - Pubic tubercle

LOCATION AND ARTICULATIONS OF PUBIS

  • Position: Proximal to the femur; Inferior to the ilium; Medial to the ischium.

  • Articulates with:
      - Ilium and ischium, Femur at hip joint.
      - Contralateral pubis at pubic symphysis joint.

THE ISCHIUM

  • Known as the ischial bone, it is one of the three bones that comprise the hip bone.

  • Thick and irregularly shaped, found along the inferolateral aspect of the pelvic girdle.

  • Parts:
      - Body
      - Ramus

  • Surfaces:
      - External and internal surfaces of ramus
      - Pelvic, dorsal, and femoral surfaces of body

  • Landmarks:
      - Ischial tuberosity
      - Ischial spine
      - Greater and lesser sciatic notches

LOCATION AND ARTICULATIONS OF ISCHIUM

  • Proximal to the femur; Inferior to the ilium; Lateral to the pubis.

  • Articulates with:
      - Ilium and pubis via triradiate cartilage in childhood (fused in adulthood)
      - Femur at the hip joint

LANDMARKS OF HIP BONE

ACETABULAR FOSSA

  • Centrally located, nonarticular, rough portion of the acetabulum.

  • Forms the floor of the acetabulum; Bound inferiorly by the lunate surface of acetabulum.

  • Filled with fat, serving as an attachment site for the ligament of the head of femur.

ACETABULAR MARGIN

  • The prominent edge around the acetabulum.

  • Site of attachment for the fibrocartilaginous acetabular labrum, deepening the cavity for femoral head.

  • Contains an inferior gap, the acetabular notch, for the passage of nerves and vessels into the hip joint.

ACETABULAR NOTCH

  • Inferiorly located gap found along the acetabular margin.

  • Continuous superiorly with the acetabular fossa and converted to the acetabular foramen by the transverse acetabular ligament, facilitating the passage of nerves and vessels into the hip joint.

ANTERIOR GLUTEAL LINE

  • Curved ridge found along the gluteal surface of ilium; longest among gluteal lines.

  • Starts along the iliac crest and travels posteroinferiorly to end at the greater sciatic notch.

  • Region between lines: origin site for gluteus minimus and medius muscles.

INFERIOR GLUTEAL LINE

  • The least distinct curved ridge along the gluteal surface of ilium.

  • Begins between ASIS and AIIS and indirectly ends at the greater sciatic notch.

  • Provides origin sites for rectus femoris and gluteus minimus muscles.

POSTERIOR GLUTEAL LINE

  • Shortest gluteal line situated along the gluteal surface of ilium.

  • It begins at the dorsal region of the iliac crest and travels posteroinferiorly to the greater sciatic notch.

  • Provides origin sites for gluteus medius and maximus muscles, and attaches to the sacrotuberous ligament.

ANTERIOR SUPERIOR ILIAC SPINE (ASIS)

  • The blunt process marking the anterior end of the iliac crest; subcutaneous.

  • Palpable at the lateral end of the inguinal fold.

  • Origin sites: sartorius and tensor fasciae late muscles; attachment for lateral end of inguinal ligament.

ARCUATE LINE OF ILIUM

  • Narrow ridge along the internal surface of the bone.

  • Extends anteromedially to form the linea terminalis (pelvic brim), separating cavities of greater and lesser pelvis.

AURICULAR SURFACE OF ILIUM

  • Ear-shaped articular area inferior to the iliac tuberosity; articulates with the sacrum.

  • Contains a groove, the preauricular sulcus, for attachment of anterior sacroiliac ligament.

GREATER SCIATIC NOTCH

  • Larger indentation along the posterior border of the coxal bone; extends from ischial spine to the posterior inferior iliac spine.

  • Formed into the greater sciatic foramen by ligaments; allows passage for piriformis, sciatic nerve, and other nerves.

LESSER SCIATIC NOTCH

  • Smaller indentation found alongside the posterior border of the coxal bone; extends from ischial spine to upper margin of ischial tuberosity.

  • Transformed into lesser sciatic foramen by ligaments; allows passage for obturator internus tendon, internal pudendal vessels, and pudendal nerve.

ILIAC TUBERCLE

  • Prominence along the iliac crest, located 5-6 cm posterior to ASIS.

  • Attachment site for iliotibial tract.

ILIAC TUBEROSITY

  • Rough area on superior surface of the sacropelvic surface of ilium.

  • Bounded anteriorly by the medial border of ilium; provides attachment sites for sacroiliac ligaments.

ILIOPUBIC EMINENCE

  • Raised area on the coxal bone marking union of ilium and superior pubic ramus.

  • Insertion site for psoas minor; attachment sites for pubofemoral ligament.

INNER LIP OF ILIAC CREST

  • Internal edge of iliac crest; provides origin for transversus abdominis and insertion for quadratus lumborum.

INTERMEDIATE ZONE OF ILIAC CREST

  • Rough area along the iliac crest, narrower in center and wider at ends; origin site for internal abdominal oblique.

OUTER LIP OF ILIAC CREST

  • External edge of iliac crest; provides origins for latissimus dorsi and tensor fasciae late muscles; attachment for fascia lata.

ISCHIAL SPINE

  • Pointed, triangular process along posterior body border; separates greater and lesser sciatic notches.

  • Provides origins for coccygeus and levator ani muscles, attachment for sacrospinous ligament.

ISCHIAL TUBEROSITY

  • Large, rounded elevation on the dorsal surface of ischium; supports the body when sitting.

  • Provides origin for hamstring muscles and attachment for the sacrotuberous ligament.

LUNATE SURFACE OF ACETABULUM

  • Smooth, horseshoe-shaped articular area covered with hyaline cartilage; articulates with the head of the femur.

OBTURATOR GROOVE

  • Wide depression on the inferior aspect of superior pubic ramus; becomes obturator canal allowing passage for obturator nerve and vessels.

POSTERIOR INFERIOR ILIAC SPINE (PIIS)

  • Sharp process along the posterior border between PSIS and greater sciatic notch; provides attachment for sacrotuberous ligament.

POSTERIOR SUPERIOR ILIAC SPINE (PSIS)

  • Blunt process marking posterior end of iliac crest; marks location by dimple on the skin; attaches to sacrotuberous and posterior sacroiliac ligaments.

PUBIC TUBERCLE

  • Small eminence found at the lateral end of pubic crest; provides insertion sites for external abdominal oblique and cremaster muscles.

FEMUR

OVERVIEW

  • The femur, or thigh bone, is the longest and strongest bone in the human body.

  • Parts:
      - Head
      - Neck
      - Body
      - Greater and lesser trochanters
      - Medial and lateral condyles

  • Surfaces:
      - Anterior, posterior, medial, and lateral surfaces
      - Medial and lateral borders
      - Linea aspera

  • Landmarks:
      - Trochanteric fossa
      - Quadrate tubercle
      - Adductor tubercle
      - Medial and lateral epicondyles
      - Pectineal line

LOCATION AND ARTICULATIONS OF FEMUR

  • Located distal to the hip bone and proximal to the tibia and fibula.

  • Articulates with:
      - Hip bone at hip joint
      - Tibia at medial and lateral femorotibial joints
      - Patella at patellofemoral joint

BODY OF FEMUR

  • Long, tubular part; continuous superiorly with neck and inferiorly with condyles.

  • Narrowest at its middle; expands at proximal and distal ends.

  • Boundaries separating body from neck:
      - Anteriorly by intertrochanteric line
      - Posteriorly by intertrochanteric crest
      - Superiorly by greater trochanter
      - Inferiorly by lesser trochanter.

HEAD OF FEMUR

  • Smooth, spherical-end articulates with acetabulum of hip bone; covered with articular cartilage.

  • Orientated superomedially, continuous with the neck.

FOVEA OF HEAD OF FEMUR

  • Small pit on medial aspect of the head for attachment of the ligament of head of femur.

NECK OF FEMUR

  • Constricted part connecting head and body; projects superomedially from the body