Thigh compartment syndrome is a medical condition where increased pressure within the muscle compartments of the thigh leads to reduced blood flow and damage to muscles and nerves. This condition requires immediate medical attention to prevent irreversible tissue damage. It is considered a surgical emergency due to the rapid onset of tissue compromise if left untreated.
Understanding Thigh Compartment Syndrome
The thigh is organized into three main muscle compartments: anterior, medial, and posterior. These compartments are enclosed by a tough sheet of connective tissue called fascia. The fascia lata is the strong, deep fascia that surrounds the thigh muscles and forms the outer boundaries of these compartments. Internal divisions are created by lateral and medial intermuscular septa, which further separate the muscle groups.
Increased pressure within these confined spaces can occur due to bleeding or swelling, often resulting from trauma. This pressure buildup compresses blood vessels and nerves within the compartment, restricting blood flow and oxygen delivery to the tissues. Without adequate blood supply, muscle and nerve cells can become ischemic, leading to tissue damage and necrosis. Common causes include severe blunt trauma, crush injuries, intense muscle exertion, or bleeding disorders.
Recognizing the Signs
Recognizing the signs of thigh compartment syndrome is important for timely intervention. Pain is often disproportionate to the apparent injury, described as severe and progressive, worsening with passive stretching of the affected muscles. For example, pain with passive knee flexion can indicate anterior compartment involvement, while passive knee extension may point to posterior compartment issues.
Other indicators include a firm or tense feeling in the affected thigh, swelling, and neurological symptoms such as numbness, tingling (paresthesia), or a burning sensation. Weakness or difficulty moving the affected limb may also be present. Pulselessness and paralysis are usually late findings, indicating severe compromise.
Diagnosis and Urgent Care
Diagnosis of thigh compartment syndrome relies on a combination of clinical assessment and objective measurements. A medical professional will perform a physical examination, looking for signs such as tenderness, swelling, and increased pain with passive muscle stretching.
Confirming the diagnosis often involves measuring the intracompartmental pressure within the thigh. This is typically done by inserting a needle attached to a pressure monitoring device directly into the muscle compartments. A normal tissue pressure ranges from 0-10 mmHg, and a pressure exceeding 30 mmHg, or within 30 mmHg of the patient’s diastolic blood pressure, generally indicates compartment syndrome and the need for immediate intervention. Prompt diagnosis and treatment are essential because irreversible muscle and nerve damage can occur within 6 to 8 hours of inadequate blood flow.
Treatment Approaches
The definitive treatment for acute thigh compartment syndrome is an emergency surgical procedure called a fasciotomy. This procedure involves making incisions through the skin and the tough fascial layers that enclose the muscle compartments. The purpose of the fasciotomy is to relieve the excessive pressure within the compartment, which then restores blood flow to the compromised muscles and nerves.
For the thigh, two fasciotomies are performed: a lateral incision and, if needed, a medial incision. The lateral incision, made along the side of the thigh, allows access to decompress both the anterior and posterior compartments. If pressure remains high in the medial compartment, a separate medial incision may be necessary to relieve it. After the pressure is released, the wound is often left open to prevent pressure from building up again, and it may be closed days later or with a skin graft. Post-surgical care includes wound management, swelling control, and a structured rehabilitation program to regain range of motion and strength.