Deep vein thrombosis (DVT)
What Is Deep Vein Thrombosis (DVT)?
Deep vein thrombosis is the formation of a blood clot (thrombus) in one of the body's deep veins. It occurs most often in the veins of the calf, thigh and pelvis. It matters greatly in orthopaedics, because major joint surgery, lower-limb fractures and prolonged immobility markedly increase the risk of DVT. A clot may stay in the leg vein, or a piece may break off and travel to the lung; for this reason DVT is taken seriously both for its local symptoms and for the life-threatening pulmonary embolism it can cause.
How Does a Blood Clot Form?
The development of a vein clot is classically explained by three factors, and these often come together in orthopaedic patients.
- Slowed blood flow: prolonged bed rest, immobility after surgery or a cast slows the blood flow in the leg.
- Damage to the vein wall: surgery or injury can injure the inner surface of the vein and start clot formation.
- Increased tendency to clot: some illnesses, medicines, pregnancy and inherited disorders make the blood more likely to clot.
What Are the Risk Factors?
The main factors that increase DVT risk include advancing age, a personal or family history of DVT or pulmonary embolism, cancer, smoking, excess weight, pregnancy, hormone therapy or the contraceptive pill, and inherited clotting disorders. For orthopaedic patients the most prominent sources of risk are major surgery (especially hip and knee replacement), lower-limb fractures and prolonged immobility. Situations that involve both trauma and surgery, such as hip fractures, raise the risk further, which is why preventive measures are planned from the outset.
How Do the Symptoms Appear?
DVT can sometimes progress without symptoms, which is part of what makes it dangerous. When present, the most common findings are swelling, pain or tenderness in one leg, redness or a change in skin colour, warmth on touch, and a firm or "cord-like" feeling along the vein. The pain often begins in the calf and can increase with standing or walking. Swelling of one leg after surgery or a fracture that is greater than expected should be assessed carefully for DVT.
Pulmonary Embolism: An Emergency
In some cases the first sign of a DVT is a pulmonary embolism, which occurs when the clot travels to the lung and is a life-threatening emergency. If sudden shortness of breath, sharp chest pain (especially worse with breathing), a fast heartbeat, coughing or coughing up blood develops, emergency medical help should be sought without delay. These symptoms can develop even without obvious leg swelling, so they must be taken seriously.
How Is It Diagnosed?
Diagnosis follows the history and examination, supported by imaging. Duplex (Doppler) ultrasound is the most common, safe and radiation-free method for diagnosing DVT. In selected cases MR venography may be used to look at the pelvic and thigh veins in detail; classic venography is rarely needed today. Blood tests such as the D-dimer help assess the likelihood of a clot in low-probability situations but do not make the diagnosis on their own. Additional clotting studies may be requested where a predisposition is suspected.
Treatment: Blood Thinners
The main aims of DVT treatment are to stop the clot from growing, to prevent pulmonary embolism, to reduce new clot formation and to minimise the risk of long-term complications. The foundation of treatment is anticoagulant (blood-thinning) medication; the doctor selects the appropriate drug, dose and duration according to the patient's situation. Because they carry a risk of bleeding, these medicines must always be used under medical supervision, and should not be started or stopped on one's own decision. In severe, high-risk selected cases, advanced treatments aimed at dissolving the clot directly may come into consideration.
Advanced Treatments and the Vena Cava Filter
In selected situations where anticoagulant treatment is not effective or cannot be used because of a bleeding risk, a filter may be placed in the main vein (the vena cava). This device aims to stop clots that break off from the leg from reaching the lung. The decision to use a filter is individual and is made only for specific indications, together with the relevant specialists. In advanced, symptomatic cases, interventional methods to dissolve the clot may also be considered.
Prevention in Orthopaedic Surgery
In major orthopaedic surgery, preventing DVT is as important as treating it, and several methods are usually combined. Early movement and getting up out of bed is one of the most effective simple measures, because it helps the leg muscles support blood flow. Compression stockings or intermittent pneumatic compression devices and, when needed, preventive-dose blood thinners can be added. The prevention plan is personalised to the type of surgery, the patient's level of risk and the risk of bleeding. In major procedures around the knee and hip these measures are part of standard care; for example, in the joint-replacement surgery covered under knee osteoarthritis treatment, prevention is planned from the outset.
The Long Term: Post-Thrombotic Syndrome
Even when treated, DVT can affect vein function in the long term in some patients. In this condition, called post-thrombotic syndrome, the affected leg may show ongoing swelling, a feeling of heaviness, pain, changes in skin colour and, in advanced cases, ulceration. Adherence to anticoagulant treatment, the use of compression stockings where appropriate and regular follow-up help reduce this risk. This assessment is also part of the follow-up after surgery for a knee or leg problem.
When Should You See a Doctor?
New swelling, pain, redness or warmth in one leg should be assessed without delay, especially if there is a recent history of surgery, fracture or prolonged immobility. Sudden shortness of breath, chest pain, a fast heartbeat, coughing or coughing up blood may signal a pulmonary embolism and require emergency medical help. To have an orthopaedic problem or a post-operative period assessed, you can contact Assoc. Prof. Serkan Sürücü.