The use of regional anesthesia techniques in orthopedic surgery is rapidly increasing due to their superior pain control, reduced opioid use, and faster recovery.1 Understanding these techniques is important for both anesthesiologists and orthopedic surgeons to enhance patient safety and optimize perioperative outcomes. Regional anesthesia techniques provide a variety of options for pain control during and after orthopedic surgeries in the lower extremities.
Regional anesthesia can be categorized into neuraxial anesthesia (i.e., spinal, epidural, or combined spinal-epidural) and peripheral nerve blocks (i.e., PNBs). Since the main target of neuraxial anesthesia is the spinal nerve roots in the thoracic or lumbar region, neuraxial anesthesia is not typically used for procedures involving the upper extremities. On the other hand, this targeted region makes neuraxial anesthesia beneficial for many abdominal, pelvic, and lower extremity procedures.2
Neuraxial anesthesia injects local anesthetics into the epidural or subarachnoid space to target spinal nerve roots. This affects sympathetic, motor, and sensory nerves, leading to parasympathetic tone. Risks include hypotension, bradycardia, nausea, and vomiting.3 However, the use of neuraxial anesthesia offers significant benefits including reduced risk of deep venous thrombosis, improved postoperative cognition, and decreased intraoperative blood loss. Spinal anesthesia involves a very thin needle and provides rapid, profound anesthesia for short procedures. While spinal anesthesia is more frequently associated with hypotension (due to rapid sympathetic blockade), this effect can be ameliorated with vigilant monitoring and prompt management.
Epidural anesthesia, on the other hand, involves a thicker needle and has a more gradual hemodynamic effect, which may offer enhanced stability. A potential complication of neuraxial anesthesia is motor block and delayed ambulation, which could delay recovery.4 The combined spinal-epidural (CSE) technique combines the rapid onset of spinal anesthesia with the flexibility and prolonged duration of an epidural. Additionally, it allows for intraoperative supplementation or postoperative analgesia. However, this technique requires careful monitoring due to a risk of delayed respiratory depression, potential catheter issues, and delayed return of motor function.
Peripheral nerve blocks inject local anesthetics near specific nerves or nerve bundles to block sensory and motor function in a targeted region, providing surgical anesthesia or postoperative analgesia. These blocks may be administered as single shots or via continuous catheters. During orthopedic surgeries involving the lower extremities, this type of regional anesthesia can take the form of femoral, saphenous, sciatic, iPACK (Infiltration between the Popliteral Artery and Capsule of the Knee), ankle, lumbar plexus blocks, and more.
The femoral nerve block is indicated for lower extremity procedures that involve the anterior thigh and/or the medial aspect of the leg below the knee. This block can effectively reduce pain and assist with rehabilitation after surgery. It is also associated with fewer unplanned postoperative hospital admissions.5 The saphenous nerve block can be used for procedures involving the knee, foot, or ankle. This technique can either be used alone, or in conjunction with the sciatic nerve block to provide increased anatomical coverage to the medial aspect of the foot and ankle. The iPACK block can provide targeted analgesia to the posterior knee capsule during surgery without weakening lower extremity strength. When combined with the adductor canal block, the iPACK block offers comprehensive anteromedial and posterior pain coverage. Its use has been shown to reduce postoperative pain, opioid consumption, and hospital stay, although careful technique and dosing are essential to avoid motor blockade or systemic toxicity.6
Regional anesthesia for orthopedic surgery of the lower extremities, including both neuraxial techniques and peripheral nerve blocks, provides effective, targeted analgesia while minimizing opioid use. These approaches can significantly improve perioperative outcomes by reducing complications, facilitating early mobilization, and enhancing overall patient recovery. Common PNBs for lower extremity procedures include femoral, saphenous, sciatic, lumbar plexus, ankle, iPACK blocks, and more. When carefully selected and administered, regional anesthesia is a cornerstone of safe, efficient, and patient-centered lower extremity surgical care.

References

1. Liu Q., Chelly J.E., Williams J.P., Gold M.S., Impact of Peripheral Nerve Block with Low Dose Local Anesthetics on Analgesia and Functional Outcomes Following Total Knee Arthroplasty: A Retrospective Study. Pain Medicine. 2015;16(5):998-1006. https://doi.org/10.1111/pme.12652
2. Kamel I., Ahmed M.F., Sethi A., Regional Anesthesia for Orthopedic Procedures: What Orthopedic Surgeons Need to Know. World Journal of Orthopedics. 2022;13(1):11-35. https://doi.org/10.5312/wjo.v13.i1.11
3. Carpenter R.L., Caplan R.A., Brown D.L., Stephenson C., Wu R., Incidence and Risk Factors for Side Effects of Spinal Anesthesia. Anesthesiology. 1992;76(6):906-916. https://doi.org/10.1097/00000542-199206000-00006
4. Verma N., Janhavi D., Spinal Versus Epidural Anaesthesia for Obstetric Delivery: A Narrative Review of Outcome Impacts. JOURNAL OF CLINICAL AND DIAGNOSTIC RESEARCH. April 1, 2025. https://doi.org/10.7860/jcdr/2025/76678.20831
5. Williams B.G., Kentor M.L., Vogt M.T., et al. Femoral-Sciatic Nerve Blocks for Complex Outpatient Knee Surgery Are Associated with Less Postoperative Pain Before Same-day Discharge. 2003;98(5):1206-1213. https://doi.org/10.1097/00000542-200305000-00024
6. Kim D.H., Beathe J.C., Lin Y., et al. Addition of Infiltration Between the Popliteal Artery and the Capsule of the Posterior Knee and Adductor Canal Block to Periarticular Injection Enhances Postoperative Pain Control in Total Knee Arthroplasty. 2019;129(2):526-535. https://doi.org/10.1213/ane.0000000000003794