bubble_chart Overview

The femur is the longest tubular bone in the human body. The femoral shaft includes the part of the bone from 2–5 cm below the trochanter to 2–5 cm above the femoral condyles. The femoral shaft is surrounded by three groups of muscles: the largest is the extensor group, innervated by the femoral nerve; the next largest is the flexor group, innervated by the sciatic nerve; and the smallest is the adductor group, innervated by the obturator nerve. Due to the well-developed muscles of the thigh, fractures often result in displacement and overlapping. The abductor muscles surrounding the femoral shaft are relatively weaker compared to other muscle groups. These abductor muscles are located in the buttocks and attach to the greater trochanter. Due to the action of the adductor muscles, the distal end of the fracture often tends to shift inward, while aligned fractures frequently exhibit an outward bowing tendency. These tendencies for displacement and angulation should be carefully corrected and prevented during fracture treatment. In fractures of the lower third of the femur, the blood vessels are located posterior to the fracture site, and the distal fragment often angulates backward, making it prone to injuring the popliteal artery and vein in that area.

bubble_chart Etiology

Most fractures are caused by strong direct violence, while a portion of fractures result from indirect violence. The former often leads to transverse or comminuted fractures, whereas the latter tends to cause oblique or spiral fractures. In children, femoral shaft fractures may be incomplete or greenstick fractures; in adults, femoral shaft fractures can result in internal bleeding of 500–1000ml.

In fractures of the upper third of the femoral shaft, the proximal fracture segment is displaced into flexion, abduction, and external rotation due to the action of the iliopsoas, gluteus medius, gluteus minimus, and external rotator muscles, while the distal fracture segment shifts posteriorly, superiorly, and medially.

In fractures of the middle third of the femoral shaft, the displacement of the fracture ends is irregular and depends on the direction of the force. If the fracture ends remain in contact without overlap, the adductor muscles cause the fracture to angulate outward.

In fractures of the lower third of the femoral shaft, the distal fracture segment often tilts posteriorly due to the traction of the posterior joint capsule and gastrocnemius muscle, posing a risk of compression or injury to the popliteal artery and vein, while the proximal fracture segment adducts and shifts anteriorly.

bubble_chart Clinical Manifestations

There is usually a history of injury, with the affected limb experiencing severe pain, impaired movement, local swelling and tenderness, abnormal mobility, and shortening of the limb. Diagnosis can be made through X-ray examination. It is particularly important to check for signs at the femoral trochanter and knee to avoid missing fistula disease, as well as other concurrent injuries such as hip dislocation, knee joint fractures, and vascular or nerve injuries.

bubble_chart Diagnosis

History of obvious trauma, pain in the affected limb, and limited movement. X-ray can confirm the location and displacement of the fracture.

bubble_chart Treatment Measures

(1) Suspension Skin Traction

Suitable for children under 3-4 years old. Both lower limbs of the child are placed in skin traction, with both legs suspended vertically upward simultaneously. The weight should be adjusted so that the child's buttocks are slightly lifted off the bed. After 3-4 weeks of traction, the traction is removed based on the bone healing shown on X-rays.

(2) Bone Traction

Suitable for the treatment of various types of fractures. For fractures of the upper 1/3 and middle 1/3 of the femur, traction through the tibial tubercle may be used; for fractures of the lower 1/3, tibial tubercle or supracondylar femoral traction may be selected.

For oblique, spiral, comminuted, or butterfly fractures, reduction occurs spontaneously during traction. For transverse fractures, reduction can only be achieved after the overlapping of the fracture is completely separated by traction.

(3) Open Reduction and Internal Fixation

Indications: a. Transverse or short oblique, butterfly fractures, or old comminuted fractures in the upper and middle 1/3 of the femoral shaft; b. Multiple segmental fractures of the femur; c. Old fractures in the middle-upper or upper 1/3 of the femur with delayed union or nonunion; d. Fractures in the upper-middle 1/3 of the femur complicated by nerve or vascular injury requiring repair; e. Multiple fractures (including femoral fractures) or polytrauma.

1. Compression Plate Internal Fixation

Indications: Transverse or short oblique fractures in the upper and middle-lower 1/3 of the femur. The AO method has gradually become popular since the 1960s and can be divided into two types: compression device plates and self-compression plates. The surgery is performed in the lateral decubitus position with a lateral thigh incision. The lateral surface of the femoral shaft is exposed anterior to the lateral intermuscular septum. After pushing aside the periosteum, the plate is placed on the lateral side of the femoral shaft.

2. Locked Intramedullary Nail Internal Fixation

In 1978, Grosse and Kempt used interlocking intramedullary nails to treat all femoral shaft fractures. The interlocking intramedullary nail has oblique or transverse holes, through which 1-2 screws are inserted into the proximal and distal ends of the fracture. Stress is transmitted through the intact bone, screws, intramedullary nail, screws, and intact bone, controlling compressive, bending, and torsional stresses at the fracture site, thereby achieving control of rotational and overlapping displacements. The Grosse-Kempt nail locks the proximal and distal cortical bone with screws, while the distal end locks the cancellous bone through the nail's bifurcation.

(4) Treatment of Open Femoral Shaft Fractures

The principles of managing open fractures have been discussed previously. After debridement and wound closure for open femoral fractures, comminuted fractures may be treated with traction, similar to the management of closed medial malleolar fractures. For cases with indications for internal fixation, except for those with mild wound contamination and surgery performed within <8 hours of injury with thorough debridement (where internal fixation can be performed immediately after debridement), internal fixation is generally recommended 10-14 days after the injury when the wound has fully healed.