Total Knee Arthroplasty (TKA), commonly known as knee replacement surgery, is a frequent procedure designed to alleviate pain and restore mobility. This operation results in a surgical mark on the knee, and understanding its appearance is a natural part of preparing for recovery. Managing expectations about the mark’s long-term changes helps patients focus on the recovery process with greater confidence.
The Standard Appearance and Location
The knee replacement surgical mark is typically a straight line running vertically down the front of the knee, usually placed along the midline or slightly to the inner side (medial aspect). The length often ranges from six to ten inches, though less invasive techniques may result in a shorter incision.
Immediately following the procedure, the incision edges are held together with surgical staples or absorbable sutures. Staples must be removed by a clinician and often leave small marks, contributing to a “railroad track” appearance. Dissolvable sutures are placed beneath the skin and do not require removal, resulting in a more uniform appearance. Regardless of the closure method, the fresh incision will appear raised and bright red or purple due to the initial inflammatory healing response.
The Timeline of Scar Maturation
The appearance of the surgical mark changes substantially as it progresses through the natural wound healing phases. In the first few weeks, the mark is in the inflammatory and proliferative stages, characterized by prominent redness, warmth, and a firm, slightly raised texture. During this time, the body rapidly lays down new collagen fibers to strengthen the wound.
The remodeling or maturation phase begins around three weeks post-surgery and can continue for 12 to 18 months. During this period, disorganized collagen fibers are rearranged into a more structured pattern, which strengthens and softens the tissue. The color of the mark will gradually shift from a deep red or purple to a lighter pink hue.
As the mark fully matures, it should flatten out and become softer to the touch. The final appearance is usually a thin line that is significantly lighter than the surrounding skin, often appearing white or hypopigmented. It will continue to fade and become less noticeable over a year or more, though it will likely never disappear completely.
Post-Operative Scar Care and Management
Once the incision is fully closed and cleared by the surgeon (typically two to four weeks post-operation), active management can begin to optimize the long-term aesthetic result. Gentle scar massage is a recommended technique, involving applying firm pressure with a moisturizer or lotion to the healed tissue. This action helps mechanically break down and reorganize collagen fibers, encouraging the mark to flatten and soften.
Consistent sun protection prevents permanent discoloration of the healing tissue. Newly formed scar tissue is particularly vulnerable to the sun’s ultraviolet (UV) rays. Exposure to UV light can lead to permanent hyperpigmentation, causing the mark to darken significantly compared to the surrounding skin. Applying a broad-spectrum sunscreen with an SPF of 30 or higher is advised whenever the mark is exposed.
Silicone products, such as gels or self-adhesive sheets, are another option supported by evidence to improve the mark’s appearance. These products work by creating a moist, occlusive environment over the mark, which helps to regulate collagen production. Consistent use of silicone can help flatten raised marks and reduce redness associated with the healing process.
Signs of Abnormal Healing
While some redness and tightness are normal during initial healing, certain signs may indicate a complication requiring prompt medical attention. Signs of a superficial infection include excessive or worsening redness, increased warmth, and tenderness around the incision site. Any persistent or increasing drainage from the wound, particularly if it is thick or discolored, should be reported to the surgical team immediately.
Abnormal scar formation can also occur, such as the development of hypertrophic or keloid scars. A hypertrophic mark is thick, raised, and red, but remains confined to the boundaries of the original incision. Keloids are a more aggressive form of excessive tissue growth, extending beyond the edges of the initial wound. Early identification allows for timely intervention to improve the final appearance.