Concerns about the cosmetic outcome of an anterior cruciate ligament (ACL) reconstruction are a natural part of the recovery process. This common orthopedic procedure restores stability to the knee joint, primarily through an arthroscopic approach that requires multiple incisions. While the presence of scars is an inevitable result of any surgery, their final appearance varies widely based on the technique used and individual healing characteristics. Understanding what contributes to the size, location, and long-term look of these marks can help manage expectations during the recovery journey.
The Size and Location of Incisions
The final scar pattern on the knee is determined by two distinct types of incisions: the small arthroscopic portals and the larger incision for graft harvest. The arthroscopic portals are small, puncture-like openings, typically two to three in number, each measuring approximately 0.5 to 1 centimeter in length. These cuts are used to insert the camera and surgical instruments required to perform the reconstruction inside the joint.
The most prominent scar results from the graft harvest site, which is necessary when using the patient’s own tissue, known as an autograft. This main incision’s size and location depend entirely on the tendon chosen to replace the torn ACL. A patellar tendon graft requires a vertical incision that can range from 6 to 8 centimeters long, located centrally on the front of the knee, running toward the tibial tuberosity.
Alternatively, a hamstring tendon graft typically results in a smaller, less noticeable scar, generally measuring 2 to 4 centimeters. This incision is placed on the medial, or inner, side of the upper shin bone where the hamstring tendons are attached. The quadriceps tendon graft usually involves a vertical incision above the kneecap, ranging approximately from 4 to 6 centimeters to harvest a section of the tendon. The size of the harvest incision is primarily dictated by the need to remove enough tissue to create a strong replacement ligament.
The Scar Maturation Timeline
The appearance of an ACL scar changes dramatically over time as the body works to repair the injured tissue. In the initial phase, which lasts for the first one to three months, the incisions will be red or dark pink, slightly raised, and may feel firm or tender. This is the inflammatory and proliferative stage, where the body rapidly produces collagen fibers to close the wound.
Following this, the scar enters a hypertrophic phase, often between three and six months post-surgery, where it may temporarily appear worse before it begins to improve. During this period, the body overproduces collagen, which can make the scar feel thicker, more elevated, and darker in color as the blood supply remains high. This temporary thickening is a normal part of the healing response.
The final and longest phase is the remodeling phase, which can continue for 12 to 18 months, or even up to two years. In this stage, the excess collagen breaks down, and the fibers restructure and align themselves. The scar will gradually flatten out, become softer, and the color will lighten considerably, often fading to a pale, thin line. The ultimate cosmetic result depends on factors like genetics, skin type, and incision management during healing.
Minimizing the Final Appearance
Consistent scar management helps ensure the best possible long-term cosmetic outcome for the incisions. The most important preventative measure is rigorous sun protection, which should begin as soon as the incisions are completely closed. New scar tissue is highly sensitive to ultraviolet (UV) radiation and will darken significantly if exposed to the sun. Covering the scar or using a broad-spectrum sunscreen with a high SPF is necessary for at least the first year of healing.
Once the stitches have been removed and the wound is fully closed, usually a few weeks after surgery, scar massage can be introduced to aid the remodeling process. This technique involves applying firm, circular pressure to the scar and the surrounding tissue multiple times a day. The mechanical pressure helps to manually break down the dense, disorganized collagen fibers that cause the scar to feel thick and raised.
The use of silicone treatments is widely accepted for managing surgical scars. Silicone sheets or topical gels create a sealed, hydrating layer over the scar, which helps to regulate collagen production and reduce the redness and thickness of the mark. These treatments are typically applied daily for several months during the remodeling phase to maximize the benefits.
While some redness and elevation are normal during healing, excessive growth may indicate a more complex issue. Signs of keloid or hypertrophic scarring, where the scar remains significantly raised, thick, or extends beyond the original wound boundaries after several months, warrant a consultation. A medical professional can assess the scar and recommend targeted treatments such as steroid injections or specific laser therapy.