In a patient with a femur fracture, is the resulting thigh pain most likely of musculoskeletal or neuropathic origin?

Thigh Pain Following Femur Fracture: Musculoskeletal Origin

In a patient with a femur fracture, the thigh pain is overwhelmingly musculoskeletal in origin, resulting from the fracture itself, associated soft tissue trauma, periosteal disruption, and muscle injury from the traumatic mechanism. 1

Primary Pain Mechanism

The femur is the largest and strongest bone in the human body, requiring tremendous force to fracture—most commonly from motor vehicle accidents in adults, falls in the elderly, or abuse in children. 1 The pain directly results from:

• Bone fracture and periosteal disruption causing immediate nociceptive pain from the fracture site itself 1
• Soft tissue trauma including muscle contusion, hematoma formation, and potential muscle/tendon injury that accompanies the high-energy mechanism required to fracture the femur 2
• Mechanical instability at the fracture site producing pain with any movement or weight-bearing 2, 3

Why Neuropathic Pain is Unlikely as Primary Etiology

While nerve injury can theoretically occur with femur fractures, the primary presenting pain in acute femur fracture is musculoskeletal, not neuropathic. The pain characteristics differ fundamentally:

• Musculoskeletal pain from femur fracture presents as deep, aching thigh pain that worsens with movement and weight-bearing 4
• The pain localizes to the fracture site and surrounding soft tissues 1
• Neuropathic pain would present with burning, shooting, or electric-shock sensations with dermatomal distribution—features not typical of acute femur fracture presentation 4

Clinical Presentation Pattern

Anterior thigh pain is the most common location (45.9% of femoral stress injuries), followed by hip pain (27%) and groin pain (8.1%). 4 In acute traumatic femur fractures:

• Pain is immediate and severe at the fracture site 1
• Patients cannot bear weight on the affected limb 2
• The thigh may be deformed, swollen, and ecchymotic from soft tissue injury 1
• Pain reproduction occurs with any attempted movement of the hip or knee 4

Postoperative Pain Considerations

Even after surgical fixation, persistent thigh pain remains musculoskeletal in nature, related to:

• Surgical trauma to muscles and soft tissues during approach 5
• Heterotopic ossification formation (present in 64% of patients with persistent pain after femoral nailing) 5
• Hardware prominence, particularly proximal locking screws 5
• Fracture healing process and periosteal remodeling 6

Important caveat: Removal of hardware does not always relieve persistent postoperative thigh pain, as the pain may result from gluteal muscle damage during nail insertion rather than hardware prominence alone. 5