Hip replacement surgery is a common procedure that can significantly improve mobility and alleviate pain. Following this operation, many individuals experience some degree of swelling in the affected leg. This is a frequent and expected part of recovery, reflecting the body’s natural response to surgery. Understanding why this occurs can help manage expectations during healing.
Expected Post-Operative Swelling
Swelling in the leg after hip replacement is primarily a result of the body’s natural inflammatory response to surgical trauma. When tissues are disrupted, the body sends fluids, including blood and lymph, to the surgical area to promote healing. This influx causes visible swelling around the hip, extending down the thigh and lower leg.
Swelling typically peaks around the second or third day post-operation, when the inflammatory response is strongest, and gradually subsides over the following weeks. However, some swelling can persist for several months, especially after strenuous activity or prolonged standing. Gravity also plays a role, making swelling more noticeable in the lower leg, such as the feet and ankles, as fluid naturally pools there. Limited movement post-surgery can slow circulation, contributing to fluid buildup.
Specific Medical Causes
Beyond expected post-operative response, certain medical conditions can cause or worsen leg swelling after hip replacement, requiring specific attention.
Deep Vein Thrombosis (DVT)
Deep Vein Thrombosis (DVT) occurs when a blood clot forms in a deep vein, most commonly in the legs. After hip replacement surgery, DVT risk increases due to changes in blood flow and clotting. A DVT obstructs normal blood flow, leading to increased pressure in veins and fluid leakage into surrounding tissues, resulting in swelling. This swelling often affects only one leg and may be accompanied by persistent pain, tenderness, warmth, or redness. Joint replacement patients are at highest risk for DVT within two to ten days after surgery, with the risk remaining elevated for approximately three months.
Infection
A surgical site infection can also cause significant leg swelling. When bacteria enter the surgical area, the body mounts an inflammatory response, leading to increased localized fluid accumulation. Infections can occur directly at the incision site or deeper within the joint. Signs include increased pain, persistent or worsening redness, warmth, and sometimes drainage from the wound. Fever and chills may also signify a systemic response.
Hematoma and Seroma
Hematomas and seromas are fluid collections that can form near the surgical site, causing localized swelling. A hematoma is a collection of blood outside blood vessels, appearing as a bruise or lump under the skin. It occurs when small blood vessels are damaged during surgery and leak blood into surrounding tissues. While some bleeding is normal, a significant collection can cause discomfort. Hematomas typically present within days of surgery.
A seroma is a collection of clear, serous fluid that accumulates in a surgically created space. Both can prevent proper tissue adhesion and may prolong recovery. These fluid collections can increase the risk of infection if they become chronically draining.
Indicators for Medical Attention
While some leg swelling is normal after hip replacement surgery, certain signs indicate a need for prompt medical evaluation. Monitor for changes that could signal a complication.
Seek immediate medical attention if you experience sudden, severe, or rapidly worsening leg swelling. This is particularly concerning if it occurs alongside intense pain not relieved by medication, or if the pain is accompanied by cramping or tenderness. New or worsening redness, warmth, or tenderness around the incision site or extending down the leg are also concerning.
Other red flags include a fever (typically above 100.4°F or 38°C) or chills, suggesting an underlying infection. Any unusual discharge from the incision site, especially thick yellow pus or blood-drenched fluid, warrants immediate medical attention. Additionally, difficulty breathing or chest pain, even without significant leg swelling, could indicate a pulmonary embolism, a serious DVT complication, requiring emergency care.