Femoral shaft fracture

A high-energy injury of the strongest bone of the body. The muscles pull the fragments into a typical deformity: the proximal fragment flexes (iliopsoas), abducts (gluteals) and rotates externally, while the adductors pull the distal fragment medially and the thigh muscles shorten it.

Mechanism

Road traffic accidents, falls from height; low-energy in osteoporotic or pathological bone (look for metastases and atypical fractures on bisphosphonates).

Clinical findings

• Deformed, short, swollen thigh. Can lose 1–1.5 litres of blood.
• ATLS: this is a marker of high energy; look for other injuries (ipsilateral femoral neck fracture in up to 9%).
• Check pulses and the sciatic nerve; compartment syndrome of the thigh is rare but possible.

Imaging

• AP and lateral of the whole femur, including hip and knee.
• Dedicated AP and axial of the hip: an ipsilateral femoral neck fracture is missed in up to a third of cases (CT of the neck in high-energy injuries).
• Trauma CT in polytrauma.

• Full-length AP and lateral of the femur including hip and knee.
• Dedicated hip views or CT to exclude an ipsilateral femoral neck fracture.

Classification

32A

Simple: A1 spiral, A2 oblique (≥ 30°), A3 transverse (< 30°).

32B

Wedge: intact or fragmented wedge; the main fragments touch after reduction.

32C

Multifragmentary: no contact between the main fragments after reduction.

Types shown in 3D

32A1

Simple spiral (torsion). Long fracture surface: heals well, but rotation must be checked.

32A2

Simple oblique (30° or more): the fragments slide and shorten.

32A3

Simple transverse (less than 30°): typical of a direct blow; stable once reduced on a nail.

32B2

Wedge (butterfly) fragment: after reduction the main fragments touch.

32C2

Segmental: a free intermediate segment. No contact between the main fragments; bridge with a nail.

Treatment

Treatment of choice

Reamed, locked intramedullary nail (antegrade through the piriformis fossa or the tip of the greater trochanter; retrograde for obesity, ipsilateral knee or acetabular injury, pregnancy or bilateral fractures). Within 24 hours if the patient is stable.

Damage control

In the unstable polytrauma patient: temporary external fixator, then convert to a nail when physiology allows (usually within 2 weeks).

Children

Under 6 months: Pavlik harness; 6 months – 5 years: hip spica cast; 5–11 years: elastic stable intramedullary nails; adolescents: rigid nail or plate.

Aftercare

Early mobilisation, weight bearing as tolerated after a locked nail in most patterns.

Complications

• Fat embolism and ARDS
• Malrotation (compare with the other side)
• Non-union
• Missed femoral neck fracture
• Pudendal nerve palsy from the traction post