ACL Surgery: Incision Locations, Graft Types, and Procedure Details

Where Do They Cut for ACL Surgery?

ACL (Anterior Cruciate Ligament) surgery, primarily reconstruction, involves several precise incisions around the knee, with their exact location and size largely determined by the type of graft material used and the minimally invasive arthroscopic technique.

Understanding ACL Reconstruction: Graft Choices and Incisions

ACL reconstruction is a procedure to replace a torn ACL with a new ligament, typically a tissue graft. The location and number of incisions are primarily dictated by whether an autograft (tissue from the patient's own body) or an allograft (tissue from a deceased donor) is used, as well as the specific type of autograft chosen.

Patellar Tendon Autograft

When a portion of the patellar tendon (which connects the kneecap to the shinbone) is used, two main types of incisions are made:

• Graft Harvest Incision: This is typically a vertical incision made on the front of the knee, directly over the patellar tendon. It can range from 3-5 centimeters (1.2-2 inches) or more, depending on the surgeon's technique and the patient's anatomy, allowing access to harvest the central third of the patellar tendon along with small blocks of bone from the kneecap and shinbone.
• Arthroscopic Portal Incisions: In addition to the harvest incision, two or three small "portal" incisions (typically less than 1 centimeter or 0.4 inches each) are made around the front and sides of the knee. These are for inserting the arthroscope (a small camera) and surgical instruments to perform the reconstruction inside the joint.

Hamstring Tendon Autograft

If hamstring tendons (semitendinosus and gracilis) are harvested from the thigh, the incision pattern differs:

• Graft Harvest Incision: A smaller incision, typically 2-3 centimeters (0.8-1.2 inches), is made on the medial (inner) side of the lower thigh or upper shin, just below the knee crease. Through this incision, the surgeon identifies and harvests the hamstring tendons.
• Arthroscopic Portal Incisions: Similar to the patellar tendon graft, two or three small portal incisions are made around the front and sides of the knee for the arthroscope and instruments.

Quadriceps Tendon Autograft

Using a portion of the quadriceps tendon (above the kneecap) is another option:

• Graft Harvest Incision: An incision is made on the front of the thigh, just above the kneecap (patella). This incision can be vertical or horizontal and is typically 2-4 centimeters (0.8-1.6 inches) long, allowing the surgeon to harvest a segment of the quadriceps tendon, often with a bone block from the patella.
• Arthroscopic Portal Incisions: As with other autografts, small portal incisions are made around the front and sides of the knee for arthroscopic visualization and instrument insertion.

Allograft (Cadaveric Tissue)

When an allograft (donor tissue, such as patellar tendon, hamstring, or Achilles tendon) is used, the procedure is entirely arthroscopic, eliminating the need for a separate graft harvest incision:

• No Graft Harvest Incision: Since the tissue comes pre-prepared from a tissue bank, there is no need to make a larger incision on the patient to obtain the graft.
• Arthroscopic Portal Incisions: Only the two or three small portal incisions are made around the front and sides of the knee for the arthroscope and instruments.

The Role of Arthroscopy in ACL Surgery

Regardless of the graft type, modern ACL reconstruction is a minimally invasive arthroscopic procedure. This means:

• Small "Portal" Incisions: These are the primary access points for the surgery itself. One portal is typically used for the arthroscope (camera), providing a magnified view of the knee's interior on a monitor. The other portals are used for specialized surgical instruments (e.g., drills, shavers, graspers) to prepare the bone tunnels, pass the new graft, and secure it in place.
• Strategic Placement: These portals are strategically placed to allow the surgeon optimal angles to visualize and work within the knee joint, typically on the front and slightly to the sides of the kneecap.

General Incision Locations and Appearance

In summary, ACL surgery involves:

• One larger incision (3-5 cm) if an autograft from the patellar tendon, hamstring, or quadriceps tendon is used, located at the specific harvest site (front of knee, medial lower thigh/upper shin, or above kneecap, respectively).
• Two to three smaller incisions (less than 1 cm each), known as portals, located on the front and sides of the knee, regardless of the graft type. These are for the arthroscope and surgical instruments.

Over time, these incisions typically heal into thin, linear scars. The visibility of the scars depends on individual healing, skin type, and sun exposure.

Factors Influencing Incision Placement

While the general locations are standard, slight variations may occur based on:

• Surgeon's Preference and Technique: Different surgeons may have preferred entry points or slightly varied approaches.
• Patient Anatomy: Individual differences in knee structure can influence optimal incision placement.
• Previous Surgeries: Prior scars or surgical history in the area might necessitate adjustments.
• Specific Graft Choice: As detailed, this is the primary determinant of the larger harvest incision.

Post-Operative Care and Scar Management

Proper post-operative care, including keeping incisions clean and dry, following wound care instructions, and eventually using scar massage or silicone sheets, can help optimize scar healing and minimize their appearance.

Conclusion

ACL surgery involves carefully planned incisions designed to minimize tissue disruption while allowing precise reconstruction of the torn ligament. The exact "cuts" will depend heavily on the chosen graft type, with the larger incision for autograft harvest and smaller, consistent arthroscopic portals for the procedure itself. Understanding these surgical access points provides clarity on the initial physical impact of this common and effective knee reconstruction.