The acetabulum is the socket of the hip joint that is part of the pelvis. An acetabular fracture occurs when this socket is broken, usually from high-energy trauma or osteoporosis in elderly patients. Treatment depends on the extent of the fracture but often involves surgery to realign the cartilage and bone and restore stability. Patients require restricted weight-bearing during recovery to avoid further injury. Long-term complications can include hip arthritis requiring replacement surgery.

1. Acetabular Fractures
What is the acetabulum?
The acetabulum is the socket of the ball-and-socket hip joint. The top of the thigh
bone (femur) forms the ball, and the socket (acetabulum) is part of the pelvic bone.
Is the acetabulum the same as the pelvis?
The acetabulum is part of the pelvis. The part of the pelvis that forms the hip socket
is the acetabulum. The acetabulum is round in shape, and covered inside with
smooth cartilage. This cartilage forms the smooth surface of the hip joint.
What is an acetabular fracture?
An acetabular fracture occurs when the socket of the hip joint is broken. This is
much less common than most hip fracture, where the ball of the ball-and-socket joint
is broken.
How does an acetabular fracture occur?
Acetabular fractures either occur with high-energy trauma (e.g. auto collisions, falls,
etc.) or as an insufficiency fracture. In younger patients, there is almost always
significant trauma, and commonly associated injuries, when an acetabular fracture
occurs. In elderly patients, acetabular fractures can occur due to bone weakened
from osteoporosis.
What is the treatment of an acetabular fracture?
In patients who have a traumatic acetabular fracture, the treatment depends on the
extent of cartilage displacement, and hip instability. The hip joint should be stable
(the ball held tightly within the socket) and the cartilage should be smoothly
contoured. Surgery is often recommended for:
• Aligning the cartilage surface
• Removing debris (bone) from within the hip joint
• Restoring stability of the hip
Elderly patients have surgery less frequently, and fractures may be allowed to heal
even if the alignment is not perfect.
Whether or not surgery is performed, patients must minimize the weight they place
on the affected extremity, often for up to three months. Patients are usually allowed
to place their foot on the ground (touch-down weight-bearing), but no more force is
allowed on the leg. Walking on the extremity too soon risks further displacement of
the broken fragments of bone.
What are the complications associated with acetabular fractures?
Unfortunately, the long-term prognosis of acetabular fractures has many potential
complications. In the early period, patients who have acetabular fractures often have
associated injuries including head injuries, abdominal injuries, urologic injuries, and
other musculoskeletal injuries (spine and knee are most common). These patients

2. are at high risk of developing blood clots in the legs and pelvis. Patients who have
surgery risk infection, nerve and blood vessel injury, and wound healing problems.
In the longer-term, the common problem is the development of hip arthritis. Patients
often eventually need a hip replacement surgery. Other possible problems include hip
osteonecrosis, heterotopic bone (excess bone) formation.