As discussed previously, a femoral neck fracture occurs just below the ball of the ball-and-socket hip joint; this region is called the femoral neck. When a femoral neck fracture occurs, the ball is disconnected from the rest of the thigh bone (the femur).
The important issue with femoral neck fractures is that the blood supply to the fractured portion of bone is often disrupted at the time of injury. Because blood flow is diminished, these fractures are at high risk of not healing, especially when the fracture is badly displaced. Due to the problem blood supply with femoral neck fractures, many will be treated by a partial hip replacement.
What is the treatment of a femoral neck fracture?
Treatment of a femoral neck fracture depends on several factors. The most important criteria to consider are:
- The amount of displacement of the fracture
- The age of the patient
For most femoral neck fractures the treatment will be one of the following:
A hip pinning is a procedure done to place several screws across the fractured bone. Hip pinning is generally only done in patients with a femoral neck fracture that is well aligned and minimally displaced. In young patients, as described above, hip pinning may be attempted even if the bones are not properly aligned. However, even in this setting, a partial hip replacement may be necessary.
When a hip pinning is performed, a patient is usually under general or spinal anesthesia. A small incision is made on the outside of the thigh. Using x-ray to guide your surgeon, several screws are passed across the fracture in order to stabilize the broken bones.
Patients can generally place as much weight on the hip as is tolerated, but this will vary in some cases--check with your surgeon before initiating any therapy or exercise. As the bones heal, the pain will generally subside. The primary concern with femoral neck fractures is that the damaged blood supply to the bone will lead to non healing or bone death (hip osteonecrosis) of the femoral head. In these cases, patients may require a hip replacement surgery down the road.
A hip hemiarthroplasty is the word used to describe a half of a hip replacement. In this procedure, the ball of the ball-and-socket joint is removed, and a metal prosthesis is implanted into the joint. Hip hemiarthroplasty is favored in patients with displaced fractures because of the complications described above with trying to rapir these fractures.
A hip hemiarthroplasty is performed under general anesthesia or spinal anesthesia. An incision is made over the outside of the hip. The fractured femoral head is removed, and replaced with a metal implant. In a normal hip replacement surgery, the socket of the pelvis would also be replaced. This can be done in patients with pre-existing arthritis of the hip, but in most cases of femoral neck fractures the socket is left alone. The prosthetic stem can be cemented into the bone in patients with thinner, more osteoporotic bone, or press-fit into patients with better bone quality.
Rehabilitation is initiated immediately and patients can usually walk with their full weight on the implant. Patients tend to feel much better after the surgery, and usually return to walking quite quickly.