Bones in the Hip
By Nikki Kelly
Bones in the Hip
The hip is made up of 2 main bones. You have the femur (the thighbone) and the pelvis. The top part of the femur, called the femoral head, is shaped like a ball. The femoral head fits into a round socket on the pelvis called the acetabulum. This causes the hip joint to be called a ball-and-socket joint. This allows for a large amount of motion allowed at the hip, which is needed for daily activities such as walking, sitting, squatting, and climbing stairs.
Now let’s go into more detail about each of these 2 bones that make up the hip.
As stated previously, the femoral head or top round part of the thigh bone is what goes into pelvis to form the hip joint. The femoral head attaches to the rest of the femur by a section called the femoral neck. There is a large bump that comes out to the side from the top of the femur. This is the greater trochanter. If you take your hand and rub it down the side of the hip, this bony prominence can be felt. Important muscles for your hip connect to the greater trochanter. One muscle that attaches there is the gluteus medius. This muscle is essential for keeping your pelvis level as you walk.
The pelvis has three parts; the ilium, pubis, and ischium. These 3 bones fuse during puberty, around the age of 15. As stated earlier, these 3 bones of the pelvis form a cup-shaped socket called the acetabulum to help form your ball-and-socket hip joint.
This is the widest and largest part of the pelvic bone and is located on the top part. This part forms the roof of the acetabulum (socket). The ilium has many important surfaces that muscles and ligaments attach to help your hip function. The wing of the ilium forms the anterior superior iliac spine (ASIS) and posterior super iliac spine (PSIS). The ASIS is the bony prominence in the front of your hips, located below and to the side of your belly button. The PSIS is located in the back of the hip, more towards the center of your spine. The ilium also has the greater sciatic notch in which the piriformis muscle and important nerves, arteries, and veins pass through.
This is the most anterior (towards the front of the body) portion of the pelvis. The pubis consists of a body, superior ramus, and inferior ramus. The pubic body articulates with the opposite side pubic body to form the pubic symphysis. The pubic symphysis helps maintain the mechanical integrity of the pelvic region. This helps absorb shock during activities such as walking, running, and aids in delivering a baby. The superior pubic ramus helps form part of the acetabulum (socket). The superior and inferior pubic ramus form the obturator foramen, allowing the obturator nerve, artery, and vein to pass through to reach the lower limb.
This forms the back and lower part of the pelvis. Like the pubis, it is composed of a body, an inferior ramus, and a superior ramus. The back lower part of the ischium forms the ischial tuberosity. When you are sitting, the ischial tuberosities are the bony prominences underneath you. These accept our body weight when sitting. Two important ligaments attach to the ischium: the sacrospinous ligament and sacrotuberous ligament.
The hip joint, a ball-and-socket joint, allows for a large amount of motion to perform all activities of daily life and sports. The hip has 2 bones and surrounding soft tissue. Injury to bones, muscles, tendons, ligaments, nerves, arteries, or small fluid-filled sacs (bursae) that cushion and lubricate the joint may cause pain in the hip. If you are having hip pain, JOI can help!
JOI Physicians are currently offering ASAP fracture and injury care. Further, this is a new option for patients who would like to avoid the emergency room if they have suffered a fracture or soft tissue injury. To learn more about this service, read this article about fracture and injury care. Make an appointment by calling (904)JOI-2000.
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Written by: Nikki Kelley