The hip is a ball-and-socket joint with the femur (ball component) articulating (in contact with) with the acetabulum (socket). Either the femur or the acetabulum can be fractured typically in specific patterns. Colloquially, the term hip fracture refers to a fracture of the femur. According to the "Journal of the American Geriatrics Society," common causes of hip fractures include osteoporosis (poor bone mineral density) and falling/trauma.
Femoral Head
Femoral head fractures occur in 6 to 16 percent of patients who have a dislocation of the hip posteriorly (through the back of the joint), according to the "AAOS Comprehensive Orthopaedic Review." This fracture refers to when there is a fracture through the ball component of the femur separating it into two or more pieces. There are a few different patterns described, however surgical and nonsurgical treatments depend on the level of displacement of the fragments and the overall stability of the joint.
Femoral Neck
The femoral neck is the component of the femur bone located in between the femoral head (ball) and the femoral shaft (thighbone). It can break in three main fracture patterns. Depending on the proximity of the fracture to the femoral head, treatment can either be with a compression screw fixation or an arthroplasty (replacement component of the joint). Fractures closer to the intertrochanteric line of the femur are treated like intertrochanteric fractures by fixation with a sliding hip compression screw to pull the pieces together.
Intertrochanteric
The intertrochanteric fracture occurs when there is a fracture along the line of the femur that connects the greater and lesser trochanter. The greater and lesser trochanters are the bony components of the femur where many of the hip muscles attach to allow for movement. The treatment is usually surgical unless the patient is nonambulatory at baseline or is too high risk for surgery.
Subtrochanteric
The subtrochanteric fracture refers to when the fracture occurs farther down the femur, closer to the start of the shaft. The fractures can create two or more fragments. Common treatments include intramedullary nailing (placing a rod through the bone) or plate fixation (a plate and screws are used to create a bridge between fragments). According to Dr. Lance Brunner's 2003 article in "American Family Physician," this fracture pattern is seen in people ages 20 to 40 and then again in people over the age of 60.
Acetabulum
Acetabular (socket) fractures occur when there is a fracture line in the socket of the hip joint. The socket may fracture so that it is no longer capable of containing the ball component of joint. Surgery is performed on these fractures when there is displacement of the fragments greater than 2 mm, when fragments prevent normal joint movement or if the joint is unstable.
References
- "Journal of the American Society of Geriatrics": Prevention of hip fractures in long-term care: relevance of community-derived data.
- "AAOS Comprehensive Orthopaedic Review"; Jay Lieberman; 2008
- "American Family Physician": Hip fractures in adults
