Swelling, also known as edema, is an expected and normal response following any knee procedure. The body interprets surgery as trauma, triggering an inflammatory response to begin the healing process. This reaction involves increased blood flow and the release of fluids into the surrounding tissues, leading to fluid accumulation. Managing this fluid buildup is important for pain control, comfort, and ensuring participation in physical therapy to regain mobility.
Immediate Physical Methods for Swelling Reduction
Immediately following surgery, the focus is on static methods to limit inflammation and encourage fluid drainage. Cold therapy (cryotherapy) is highly effective because it constricts blood vessels, slowing blood flow and reducing fluid entering the area. Apply an ice pack or cooling device to the knee for 15 to 20 minutes at a time, repeating every one to two hours during the first few days of recovery. A thin cloth barrier must always be placed between the ice pack and your skin to prevent injury.
Compression physically limits the space available for fluid accumulation in the soft tissues around the joint. This is achieved using an elastic bandage, a Velcro wrap, or medical-grade compression stockings. The garment should be snug enough for firm support but not so tight that it causes numbness, throbbing, or discoloration in the foot, which indicates impaired circulation.
Elevation uses gravity to help drain excess fluid back toward the torso, assisting both the venous and lymphatic systems. For maximum effectiveness, the ankle and foot must be positioned above the level of the heart. Prop the leg up on a stack of pillows or a wedge while lying down, maintaining this position for 15 to 30 minutes several times throughout the day. Consistency with elevation is beneficial, especially following activity.
The Role of Movement and Positioning in Fluid Drainage
Once allowed by your care team, gentle movement is an effective dynamic strategy for managing swelling and improving circulation. The lymphatic system, which clears fluid and waste, relies on muscle contractions to pump lymph fluid out of the limb. Relying solely on static methods, like elevation, will not fully activate this natural clearance mechanism.
Gentle, repetitive exercises such as ankle pumps, where you point your toes up toward your head and then down, act as a calf muscle pump to encourage blood and fluid return. Light range-of-motion exercises, like heel slides or quad sets, gently mobilize the joint and help push fluid away from the surgical site without causing strain. Perform these controlled movements multiple times per day to maximize the fluid clearing effect.
When sitting or resting, avoid letting the leg hang down for extended periods, as gravity pulls fluid toward the foot and ankle. When seated, ensure your leg is propped up to keep the knee above the hip, or ideally, above heart level. Maintaining a slightly elevated position during sleep helps prevent the pooling of fluid that often worsens swelling overnight.
Recognizing Abnormal Swelling and Complications
While swelling is expected for weeks or months after knee surgery, it is important to distinguish between normal recovery and a complication. Swelling that is rapidly increasing, dramatically worsening, or not relieved by rest, elevation, and cold therapy warrants immediate medical attention. These changes can signal a serious underlying problem.
One concern is Deep Vein Thrombosis (DVT), a blood clot in the deep veins of the leg, which presents as severe, sudden swelling, often in the calf or ankle, accompanied by new pain, tenderness, or warmth. Infection is another serious complication, indicated by swelling coupled with systemic symptoms like fever and chills, or local signs such as intense redness, disproportionate warmth, or discharge from the incision site. If you experience any of these red flags, contact your medical team immediately.