Femoral head fracture

A femoral head fracture is a rare type of hip fracture that involves a break in the rounded portion of the thigh bone (femur) that fits into the hip socket.^[1] They are estimated to account for less than 1% of all hip fractures, with two-thirds of those affected being young adults.^[1][2] These injuries are typically sustained during high-impact events, such as car accidents or falls from significant heights.^[2]

Signs and symptoms

Typical presenting findings include pain in the groin, along with swelling and bruising around the hip.^[1] Patients are generally unable to walk or bear weight on the affected leg.^[1] Femoral head fractures also commonly occur in association with posterior hip dislocation.^[2] In these cases, the affected leg is usually in a flexed, adducted, and internally rotated position. The affected leg may appear shorter compared to the unaffected leg.^[2] Sciatic nerve injury can also occur, especially in cases of fracture with dislocation.^[3] This may manifest with absent or diminished reflexes and weakness when bending the knee or moving the foot.^[4]

Diagnosis

Imaging

Plain radiographs of the pelvis taken from the front (AP view) are the initial imaging method of choice for isolated injuries.^[2] Additional views can help identify accompanying injuries, such as acetabular fractures.^[2] CT scans are often used in trauma patients with multiple serious injuries or after reduction to further evaluate the hip joint.^[2] MRI may be used if there is suspected damage to the cartilage of the hip socket or suspected early osteonecrosis.^[2]

Classification

The Pipkin classification is the most frequently used method to categorize femoral head fractures and is organized as follows:^[5]

Pipkin classification type	Description
I	Fracture below the fovea; not involving weight-bearing surface of the head
II	Fracture above the fovea; involving weight-bearing surface of the head
III	Type I or II fracture with associated femoral neck fracture
IV	Type I or II fracture with associated acetabulum fracture

This classification system helps to guide management and predict outcomes.^[2]

Treatment

Initial physical examination should include assessment of circulation and nerve function in the affected leg, particularly in the distribution of the sciatic nerve.^[3] In cases with hip dislocation, urgent reduction is required, with earlier intervention being predictive of a better outcome.^[6] Definitive management in younger patients may involve surgical options such as open reduction and internal fixation or fragment removal.^[6] In contrast, total hip replacement is generally favored in elderly patients.^[6]

Prognosis

There are multiple scoring systems used to assess outcomes following recovery, including the Thompson and Epstein outcome score, Merle d'Aubigné and Postel score, and the Oxford Hip Score.^[3] Using these scoring systems, good to excellent outcomes are achieved in about two-thirds of cases.^[3] However, the association of the injury with pain, joint stiffness, and loss of function contributes to variability in treatment outcomes.^[6] Common long-term complications include posttraumatic arthritis, osteonecrosis of the femoral head, and heterotopic ossification.^[3]

Epidemiology

Although still uncommon, the incidence of femoral head fractures has increased in recent times.^[2] This trend is thought to be the result of two main factors: an increase in motor vehicle accidents and advances in modern vehicle safety, which have increased survival and allowed for more frequent identification of these fractures.^[2]

See also

• Femoral neck