What Kind of Anesthesia is Used for ACL Surgery?

October 9, 2025 •

3 min read

Over 100,000 anterior cruciate ligament (ACL) reconstructions are performed annually in the United States. If you are preparing for this common procedure, you may wonder, what kind of anesthesia is used for ACL surgery? The primary options include general anesthesia, regional anesthesia, and peripheral nerve blocks.

Quick Summary

The main types of anesthesia for ACL surgery are general anesthesia, regional anesthesia like a spinal or epidural block, and peripheral nerve blocks. The choice depends on the patient's health, surgeon preference, and the specifics of the surgery.

Key Points

Main Options: The primary anesthesia choices for ACL surgery are general anesthesia, regional anesthesia (spinal/epidural), and peripheral nerve blocks.
General Anesthesia: Induces complete unconsciousness, but may have more side effects like nausea and grogginess.
Regional Anesthesia: Numbs the lower body, often allowing for a smoother recovery with less nausea and a lower risk of blood clots.
Nerve Blocks are Key: Peripheral nerve blocks are crucial for postoperative pain management, reducing the need for opioids.
Adductor Canal Block Advantage: The adductor canal block (ACB) provides pain relief comparable to a femoral nerve block but better preserves quadriceps strength, aiding in early rehabilitation.
Multimodal Strategy: Modern practice often combines techniques, such as a spinal block with a peripheral nerve block, for optimal results.
Patient-Specific Choice: The final decision on anesthesia is tailored to the individual, based on their health, surgeon preference, and the specifics of the surgery.

Navigating Anesthesia for ACL Reconstruction

Anterior cruciate ligament (ACL) reconstruction is a common orthopedic procedure associated with moderate-to-severe postoperative pain. Effective anesthesia is crucial not only for comfort during the operation but also for managing pain afterward, which is vital for early mobilization and a successful recovery. Anesthesiologists and surgeons select the best method based on the patient's health, the complexity of the surgery, and patient preference. The main categories of anesthesia used are general anesthesia, regional anesthesia, and peripheral nerve blocks, which are often used in combination.

General Anesthesia

General anesthesia induces a state of complete unconsciousness, rendering the patient unaware of the surgery. It is administered through an IV and may involve inhaled gases to maintain the anesthetic state. A breathing tube is inserted to assist with respiration during the procedure. Common side effects can include nausea, vomiting, drowsiness, and a sore throat after waking up. While major complications like heart attack or stroke are rare, risks can be elevated for patients with pre-existing heart or lung conditions.

Regional Anesthesia: Spinal and Epidural Blocks

Regional anesthesia numbs a large area of the body, typically the lower half, while the patient may remain conscious or sedated. For ACL surgery, common types include spinal anesthesia, which involves a single injection into the spinal fluid for rapid, temporary numbness, and epidural anesthesia, which uses a catheter for continuous medication delivery. Regional anesthesia is associated with less nausea, a smoother recovery, and reduced risks of blood loss and clots compared to general anesthesia. Patients usually breathe independently. A potential side effect is a headache.

Peripheral Nerve Blocks for Targeted Pain Control

Peripheral nerve blocks (PNBs) target specific nerves to block pain in the knee area and are a vital part of pain management for ACL surgery, often combined with general or spinal anesthesia. These blocks are typically guided by ultrasound.

Common nerve blocks for ACL reconstruction include:

Femoral Nerve Block (FNB): Numbness in the front of the thigh and knee. Can cause quadriceps weakness, potentially affecting rehabilitation and increasing fall risk.
Adductor Canal Block (ACB): A sensory-focused alternative to FNB that provides similar pain relief with less impact on quadriceps strength, aiding early recovery and range of motion.
Sciatic Nerve Block: Targets the back of the knee, often used with FNB or ACB for broader pain control, especially with hamstring grafts.
Femoral-Obturator-Sciatic (FOS) Block: Blocks three main nerves for comprehensive anesthesia and pain control with minimal opioid use.

Nerve blocks generally last about 15 hours, but continuous catheters can provide longer-lasting relief.

Comparison of Anesthesia Types


Anesthesia Type	Key Advantages	Key Disadvantages	Ideal For...
General Anesthesia	Patient is completely unconscious; no memory of surgery.	Higher incidence of nausea, vomiting, and drowsiness post-op; requires breathing tube.	Patients who prefer to be completely asleep or for more complex reconstructions.
Regional Anesthesia (Spinal/Epidural)	Less nausea; reduced blood loss and clot risk; patient breathes independently.	Small risk of post-procedure headache; temporary inability to move legs.	Most patients; often preferred for potentially smoother recovery.
Peripheral Nerve Blocks (e.g., ACB)	Excellent, targeted post-op pain control; reduced need for opioids; preserves muscle strength (especially ACB).	Block eventually wears off, requiring transition to oral pain meds; risk of nerve injury is rare.	Part of a multimodal pain strategy for nearly all ACL surgeries to enhance recovery.

Conclusion: A Multimodal Approach

All anesthesia types are considered safe for outpatient ACL reconstruction. A multimodal approach, combining techniques like a spinal block with a peripheral nerve block, is often used to maximize benefits and minimize side effects. This strategy reduces reliance on opioids and supports early physical therapy, essential for recovery. The final anesthesia plan is a collaborative decision involving the patient, surgeon, and anesthesiologist.

For further reading, you can explore information from the American Academy of Orthopaedic Surgeons on Anesthesia for Hip and Knee Surgery.

Frequently Asked Questions

It depends on the type of anesthesia used. With general anesthesia, you will be completely asleep. With regional anesthesia (like a spinal block), you can be sedated to a point where you are relaxed and may not remember the surgery, even if you are not fully unconscious.

All major types of anesthesia (general, spinal, and nerve blocks) are commonly used and considered safe for ACL reconstruction. The choice often depends on the patient, surgeon, and anesthesiologist. Many procedures use a combination of techniques.

A single-injection nerve block typically provides pain relief for about 12 to 15 hours. If a continuous catheter is used, the block can last for as long as the catheter remains in place, often for several days.

Regional anesthesia is often associated with a smoother recovery, less nausea and vomiting, reduced blood loss, and a lower risk of developing blood clots compared to general anesthesia.

A femoral nerve block (FNB) provides strong pain relief but also causes significant weakness in the quadriceps muscle. An adductor canal block (ACB) provides similar pain relief but has much less effect on quadriceps strength, which can help with earlier mobilization and physical therapy.

While generally very safe, risks can include nausea, vomiting, and headache. More serious but rare complications can include allergic reactions, nerve injury, infection, blood clots, and heart or breathing problems.

Yes, you will transition to oral pain medications as the nerve block wears off. A multimodal pain management plan, which may include non-steroidal anti-inflammatory drugs (NSAIDs) and other non-opioid medications, is used to manage pain and minimize the need for opioids.