Complications and technical failures in femoral neck fracture management

Complications of the femoral neck fracture include:

Nonunion
Avascular necrosis
Failure of fixation

Nonunion is caused by:

Severity of the injury or displacement
Shearing fracture configuration
Inadequate reduction or
Unstable internal fixation

Nonunion can be prevented by anatomical reduction and stable internal fixation.

In most cases, the fracture will displace into varus position.

If the blood supply to the femoral head is preserved, a valgus trochanteric osteotomy is a promising salvage procedure.

Case

In this case, a basicervical femoral neck fracture was stabilized with multiple screws.

$AP x-ray of a basicervical femoral neck fracture$

Postoperative AP and lateral views

$Postoperative AP and lateral x-rays of a basicervical femoral neck fracture fixed with cancellous screws$

At 4 months follow-up, the fracture did not heal and displaced into varus deformity.

Note: For this fracture pattern, screw fixation is not stable enough to withstand the shearing forces by weight bearing. Better fixation options include the femoral neck system or a sliding hip screw with antirotation screw.

$Follow-up x-ray of a basicervical femoral neck fracture fixed with cancellous screws with the proximal fragment displaced into varus deformity$

The nonunion was treated with valgus trochanteric osteotomy.

At 2 years, the femoral neck fracture healed, and the implant was removed.

$Nonunion of a basicervical femoral neck fracture treated with valgus trochanteric osteotomy$

Avascular necrosis usually occurs in grossly displaced fractures. The vascular supply to the femoral head is jeopardized, especially the retinacular vessels.

Careful open reduction using an anterior approach will avoid iatrogenic injury to the blood supply of the femoral head.

Continued long-term follow-up is necessary since subchondral collapse due to avascular necrosis may take 2–3 years to become apparent on x-rays.

In most cases, it is treated with total hip arthroplasty.

Case

A transcervical femoral neck fracture was stabilized with multiple screws.

At six months, the fracture healed, but avascular necrosis with subchondral collapse occurred.

$Preoperative x-ray of a transcervical femoral neck fracture; follow-up x-ray with screw stabilization showing avascular necrosis with subchondral collapse$

The final treatment was hemiarthroplasty.

AP x-ray of a hemiarthroplasty of the hip joint

This image shows the condition of the articular cartilage of the femoral head with partial collapse.

Removed femoral head showing partial collapse of the articular cartilage

In poor-quality bone

Failure of fixation is related to poor bone quality, especially in elderly patients with osteoporosis. Fixation of a displaced femoral neck fracture in osteoporotic bone usually ends up with implant loosening or loss of fixation.

Careful evaluation of the x-rays is necessary to determine whether the fracture is nondisplaced or displaced.

If there is displacement, attempts for anatomical reduction and internal fixation often lead to failure of fixation. Arthroplasty is the preferred choice in this case.

Case

This case shows a transcervical fracture of the femoral neck in an elderly patient with osteoporosis.

$AP x-ray of a transcervical femoral neck fracture in a patient with osteoporosis$

It was reduced closed and stabilized with multiple screws.

At 6 weeks follow-up, the fracture displaced and collapsed into varus.

$Postoperative and follow-up x-rays of a transcervical femoral neck fracture showing displacement and collapse into varus after 6 weeks$

In good-quality bone

In young adults, failure of fixation is mainly related to technical errors. The quality of reduction is the most important factor in predicting healing (or implant failure).

Unstable fracture configurations, eg, shearing fracture types, need more stable implants, eg, sliding hip screw combined with an antirotation screw, or the femoral neck system (FNS).