Anterior Cruciate Ligament (ACL) Repair

Anesthesia Implications

Position: Supine, arms at side on armboards
Time: 1-2 hours (average)
Blood Loss: Moderate (50 – 200 ml)
Post-op Pain: Moderate (3-6)
Maintenance Paralytic: Yes
Tourniquet Use: Yes
Blocks: Adductor Canal, Femoral, IPACK

Approach – Sometimes you can get away with an GLMA. The difficulty is that these surgeries can take awhile. Tourniquet pain will set in, and breathing will get difficult to control. For this reason, most opt to use a GETT approach with paralytic. Some facilities/surgeons are efficient enough to have the surgery done in less than 90 minutes. In cases like these, it has been suggested that propofol sedation along with spinal anesthesia and peripheral nerve blocks (eg. adductor canal and IPACK) are a good approach and require little/no narcotics.

Wakeup – Keep the patient asleep until they put on the splint or cast at the end.

Antibiotic – Cefazolin IV

Tourniquet (general considerations): Antibiotics should be administered prior to tourniquet inflation. Tourniquet pain usually begins 45-60 minutes after inflation and is unresponsive to regional anesthesia and analgesics. Upper extremity pressure should be set to approximately 70-90 mmHg above systolic blood pressure (SBP). Lower extremity tourniquet pressure should be set to approximately 2 times SBP. Upon tourniquet release, there will be increases in End-tidal CO2 and metabolic acidosis, while decreases will be seen in core body temperature, blood pressure, and mixed venous oxygen saturation (SvO2)

Trauma is the most common indication. Trauma patients are typically young and healthy and usually have torn the ligament after a sport injury.
Cruciate tears are only repaired if bone is torn away at one end of the ligament.

Four main ligaments connect the femur and tibia. These include the medical collateral ligament (MCL) which prevents the one from bending out, anterior cruciate ligament (ACL) which prevents the tibia bone from sliding out in front of the femur, lateral collateral ligament (LCL) which runs along the outside of the knee, and posterior cruciate ligament (PCL) which prevents the tibia from sliding back under the femur.

A medial parapatellar with anterior arthrotomy approach is taken for the ACL repair. The ligament is repaired by direct suture or by attaching it to bone with a screw or staple. A reconstruction is performed for instability. Allografts, synthetics, or homografts (a piece of the patellar tendon or semitendinosus tendon) are typically used.