Intracapsular Fractures

Mechanism of Injury

Fractures usually arise as a result of a fall onto the greater trochanter. The typical scenario is where the patient slips or trips at home. The patient may also be suffering from other co – current medical conditions, such as problems with gait and balance and muscle control which further increase the chances of falling.

Classification

Garden’s classification (1961) is most commonly used:

• Stage 1 - incomplete impacted fracture of the femoral neck
• Stage 2 - complete but undisplaced fracture
• Stage 3 - complete fracture with moderate displacement
• Stage 4 - severely displaced fracture

Clinical Features

The patient complains of pain in the hip following a fall. In fractures that are not impacted, the affected leg is shortened and externally rotated. The patient is unable to weight bear on the affected leg. With impacted fractures, the patient may still be able to walk on the affected leg. Tenderness may be found in the region of the femoral neck.

X-rays of the hip are essential: AP film of the pelvis and lateral film of the injured hip are required.

Associated Injuries

Avascular necrosis of the femoral head may occur if the blood supply is affected. Dislocation of the hip or pelvic fractures may also occur.

Blood supply to the hip

In order to understand the treatment of intra-capsular femoral neck fractures, it is important to recall to attention the blood supply to the femoral head. Blood supply to the femoral head is from three main sources:

• Intramedullary vessels in the femoral neck
• Ascending cervical branches in the capsular retiniculum
• Vessels following the ligamentum fovea

In all fractures, the intramedullary supply is disrupted. In displaced fractures, the retinacular vessels may also be disrupted. As a result of the pattern of blood supply, the greater the degree of displacement in femoral neck fractures the greater the incidence of avascular necrosis of the femoral head.