Central Hip Dislocation

MANUAL MINORS

A central hip dislocation is a severe injury where the femoral head is displaced medially, through a fractured acetabulum into the pelvis. This dislocation is always accompanied by an acetabular fracture due to high-energy trauma, such as car accidents or falls from heights. It is a medical emergency because it can compromise blood vessels, nerves, and cause intra-abdominal injuries.

Diagnosis

Clinical diagnosis includes severe pain in the hip and groin, inability to move the affected leg, and limb shortening or deformity. The pelvis may present a palpable internal protrusion of the femoral head.

A pelvic X-ray confirms the diagnosis by showing medial displacement of the femoral head and fractures of the acetabulum. Computed tomography (CT) is essential to assess the extent of bone damage and rule out associated injuries.

Differential Diagnosis

Condition	Key Differentiation
Posterior hip dislocation	The femoral head is displaced backward, with internal rotation of the leg
Anterior hip dislocation	Displacement of the femoral head forward, with external rotation of the leg
Femoral neck fracture	No displacement into the pelvis, though the femoral head may be displaced
Acetabular fracture without dislocation	No loss of congruence between the femoral head and acetabulum
Avascular necrosis of the femoral head	Chronic presentation, with no history of acute trauma

Emergency Management

Emergency management includes stabilising the patient, providing pain relief with strong analgesics, and in the case of open fractures or associated injuries, administering antibiotics and tetanus prophylaxis.

Hip immobilisation is crucial until surgical intervention can be performed. It is essential to rule out associated intra-abdominal or vascular injuries, so detailed abdominal and pelvic assessment is indicated, especially in patients with high-energy trauma.

Definitive Treatment

Definitive treatment is surgical, involving open reduction and internal fixation of the acetabulum and femoral head. This procedure aims to restore the hip’s anatomy and prevent complications such as avascular necrosis or post-traumatic arthritis. The prognosis depends on the severity of associated injuries and the time elapsed before reduction. Post-surgery, the patient will require prolonged rehabilitation, with weight-bearing restrictions on the affected leg and follow-up imaging to monitor fracture healing and femoral head viability.