Study Notes on the Anatomy of the Pelvic and Lower Limb Bones

Anatomy of the Pelvic and Lower Limb Bones

Pelvic Bones

  • Ilium: The largest part of the hip bone. It helps to form the sides of the pelvis.

  • Sacrum: A triangular bone located at the base of the vertebral column, consists of five fused vertebrae.

  • Sacroiliac Joint: The joint between the sacrum and the ilium, important for weight transfer between the upper body and legs.

  • Ischium: The lower and back part of the hip bone, it forms the lower posterior part of the pelvis.

  • Iliac Fossa: A concave surface on the internal side of the ilium, which houses important muscles.

  • Acetabulum: The socket in the pelvic bone for the head of the femur, forming the hip joint.

  • Obturator Foramen: A large opening in the hip bone formed by the ischium and pubis, through which nerves and blood vessels pass.

  • Pubis: The anterior portion of the pelvic bone. It has a symphysial surface for articulation with the opposite pubis at the pubic symphysis.

  • Pubic Symphysis: A cartilaginous joint where the left and right pubic bones meet in the front.

Major Structures of the Pelvis

  • Greater Sciatic Notch: A large notch that allows for the passage of structures from the pelvis to the leg.

  • Ischial Spine: A bony projection from the ischium, important for muscle attachment.

  • Ischial Tuberosity: The part of the ischium that bears weight when sitting.

  • Lesser Sciatic Notch: A smaller notch below the greater sciatic notch.

  • Iliac Crest: The upper margin of the ilium, commonly referred to as the "hip bone".

  • Anterior Superior Iliac Spine (ASIS): A prominent bony projection on the iliac bone, used as a landmark for making anatomical measurements.

  • Posterior Superior Iliac Spine (PSIS): Similar to ASIS but located at the back of the iliac bone.

Femur Anatomy

  • Head: The rounded proximal end of the femur that articulates with the acetabulum of the pelvis.

  • Fovea Capitis: A small pit in the head of the femur for the attachment of a ligament.

  • Patellar Surface: The area where the patella (kneecap) rests, located at the distal femur.

  • Neck: The narrow region below the head of the femur.

Posterior Features of the Femur

  • Greater Trochanter: A large, irregularly shaped bony prominence for muscle attachment on the femur’s lateral side.

  • Lesser Trochanter: A smaller bony prominence on the femur’s medial side.

  • Lateral Condyle: The outer part of the femur that articulates with the tibia.

  • Medial Condyle: The inner part of the femur for articulation with the tibia.

  • Gluteal Tuberosity: A roughened area on the posterior femur for gluteal muscle attachment.

  • Linea Aspera: A prominent ridge along the length of the posterior femur.

  • Lateral Epicondyle: A bony prominence above the lateral condyle.

  • Medial Epicondyle: A bony prominence above the medial condyle.

  • Intercondylar Fossa: A deep notch between the condyles for the attachment of ligaments.

Tibia and Fibula Anatomy

  • Medial Condyle: The medial articulation point of the tibia with the femur.

  • Lateral Condyle: The lateral articulation point of the tibia with the femur.

  • Anterior Crest: The sharp ridge on the anterior surface of the tibia.

  • Tibial Tuberosity: A bony prominence on the tibia where the patellar ligament attaches.

  • Intercondylar Eminence: A raised area between the condyles of the tibia, serving as a ligament attachment point.

  • Medial Malleolus: The bony prominence on the inner side of the ankle, formed by the distal end of the tibia.

Fibula Structures

  • Head: The upper end of the fibula that articulates with the tibia.

  • Patella: The kneecap, a flat, triangular bone located in front of the knee joint.

  • Lateral Malleolus: The bony prominence on the outer side of the ankle, formed by the distal end of the fibula.

Foot Bones

  • Metatarsals (5): The long bones in the foot, numbered from 1 to 5 starting with the big toe.

  • Digits (5): The toes of the foot, consisting of the big toe (Hallux) and four others.

  • Tarsals (7): The seven bones that make up the ankle and part of the foot, including:

    • Talus: The ankle bone that connects the leg to the foot.

    • Calcaneus: The heel bone, the largest tarsal bone.

Phalanges of the Toes

  • Hallux (Great Toe): The first toe, which has two phalanges.

  • Distal Phalanx: The terminal bone of each toe, except for the hallux.

  • Proximal Phalanx: The bone closest to the foot in each toe, except for the hallux.

  • Middle Phalanx: Present in all toes except for the hallux.