Differential Diagnosis for Postoperative Right Thigh Pain

The patient presents with severe right thigh pain 1 day postoperative from a right ACL reconstruction, with the knee pain being manageable. The differential diagnosis can be categorized as follows:

• Single Most Likely Diagnosis

  • Compartment Syndrome: This is a highly plausible diagnosis given the severe thigh pain postoperatively. Compartment syndrome is a condition where pressure within the muscle compartments increases, potentially leading to muscle and nerve damage. It is a known complication of surgeries like ACL reconstruction, especially if there has been significant bleeding or swelling within a closed compartment.

• Other Likely Diagnoses

  • Deep Vein Thrombosis (DVT): Postoperative patients are at an increased risk for DVT due to immobility and the hypercoagulable state that can occur after surgery. Severe thigh pain could be a symptom of a DVT, especially if it's associated with swelling, warmth, and discoloration of the leg.
  • Nerve Injury: Direct trauma to nerves during the surgery or from positioning could result in severe pain. The femoral nerve is particularly at risk during knee surgeries and could cause thigh pain.
  • Hematoma: A collection of blood outside of blood vessels could cause pain and swelling. A large hematoma in the thigh could compress surrounding structures, leading to significant pain.

• Do Not Miss Diagnoses

  • Pulmonary Embolism (PE): Although the primary complaint is thigh pain, it's crucial not to miss a potential PE, which could present with sudden onset of chest pain, shortness of breath, or could be asymptomatic. A DVT in the leg significantly increases the risk of a PE.
  • Infection: Early postoperative infection could present with pain, redness, swelling, and warmth around the surgical site. It's less likely this early but is a critical diagnosis not to miss due to its potential for serious complications.

• Rare Diagnoses

  • Rhabdomyolysis: This condition involves the breakdown of muscle tissue and can be caused by severe injury, including surgical trauma. It's rare but could present with severe muscle pain and is important to consider due to its potential for causing kidney failure.
  • Arterial Injury: Direct injury to arteries during surgery could lead to severe ischemia of the limb, presenting with severe pain, pallor, pulselessness, poikilothermia, paresthesias, and paralysis. This is rare but would be an emergency requiring immediate intervention.