A total knee replacement (TKR) is a major surgical procedure, and a visible scar is a natural and expected result. It is common for patients to feel anxiety about its eventual appearance. Understanding how the incision heals, from the initial post-operative look to its final, mature state, helps set realistic expectations. The scar’s final appearance is influenced by the surgical method used, individual biology, and diligent post-operative care.
Immediate Post-Surgical Appearance
Immediately following the procedure, the incision for a traditional total knee replacement is typically a long, vertical line situated directly over the center of the kneecap. This conventional approach often measures between eight and ten inches, allowing the surgeon sufficient access to the joint space. The wound will appear red and slightly raised, which is a normal inflammatory response as the body begins the healing process.
Closure materials like staples, sutures, or surgical glue hold the skin edges together. The surrounding area will display significant swelling, bruising, and warmth due to the trauma to the underlying tissues. Bruising, often black and blue, can extend down the leg but is a temporary side effect. This initial appearance is the most dramatic and changes rapidly as the wound begins to close in the first few weeks.
How the Scar Changes Over Time
The healing of the surgical wound proceeds through a predictable sequence of stages that determine the scar’s mature appearance. Following the initial inflammatory period, the body enters the proliferative stage, typically starting around one week post-surgery. New collagen fibers are rapidly laid down to bridge the incision, and the scar may feel firm, slightly raised, and tight as the new tissue gains strength.
The maturation stage begins approximately three weeks post-operation and can continue for up to a full year as collagen fibers reorganize and strengthen. In the first few months, the scar often appears dark red or purple and can be noticeably raised (the hypertrophic phase). Over the next several months, the color will gradually lighten, and the thickness will decrease as the blood vessels within the new tissue regress.
A mature knee replacement scar, typically seen around the twelve-month mark, will have flattened and softened, transforming into a pale, silvery, or white line. The final appearance depends on individual factors like genetics and skin tone, which influence collagen production. Consistent protection from direct sun exposure is important, as ultraviolet light can cause the new tissue to darken permanently. The tension placed on the scar from the constant bending and straightening of the knee can also influence how wide and noticeable the final mark becomes.
Variations Based on Surgical Approach
The appearance of the scar is significantly influenced by the surgical technique used for the total knee replacement. The traditional approach requires a longer eight-to-ten-inch vertical incision, providing the surgeon maximum visualization of the joint. This results in the longest type of knee replacement scar, running centrally down the front of the joint.
In contrast, minimally invasive total knee replacement (TKR) techniques use a shorter incision with less disruption to surrounding soft tissues. The resulting incision is typically shorter, often measuring between four and six inches in length. Highly specialized, quadriceps-sparing techniques may result in a scar as short as three or four inches. Although the minimally invasive approach results in a smaller scar, the placement remains generally central and vertical over the knee.