Foot and ankle surgeries, such as hallux valgus corrections and trauma repairs, are frequently associated with moderate to severe postoperative pain1,2. Effective management of this acute pain is a critical element of modern surgical care, with peripheral nerve blocks largely anchoring modern anesthetic regimens2,3. While general and spinal anesthesia remain common options for podiatric surgery, peripheral nerve blocks offer substantial clinical advantages, including extended postoperative analgesia, decreased systemic opioid requirements, and an improved side-effect profile2.
When comparing peripheral nerve blocks to spinal anesthesia for podiatric surgery, both techniques provide adequate intraoperative surgical conditions. However, spinal anesthesia is often associated with a higher incidence of hemodynamic instability, particularly hypotension resulting from sympathetic nerve blockade. Conversely, peripheral nerve blocks offer excellent hemodynamic stability, making them highly suitable for patients with compromised cardiopulmonary function or severe systemic comorbidities. Furthermore, while spinal anesthesia typically features a shorter block performance and onset time, peripheral nerve blocks can significantly extend the duration of both sensory and motor blockade, which directly translates to a substantial reduction in postoperative analgesic consumption and opioid dependency2.
The anatomical complexity of the foot and ankle necessitates a precise approach to regional anesthesia. The sensory innervation of this region is primarily supplied by five key nerves: the saphenous, superficial fibular, deep fibular, sural, and tibial nerves3. Blockade of these nerves can be performed proximally, such as via a popliteal sciatic nerve block, or more distally at the level of the ankle1,3. A 2022 review found that, for hallux valgus surgery, ankle blocks provide superior analgesic efficacy compared to both control groups and localized peri-incisional infiltration.
Ankle blocks effectively decrease postoperative pain scores, reduce the need for rescue opioids, and lower the incidence of postoperative nausea and vomiting1. Although popliteal blocks are similarly effective in controlling postoperative pain, they induce foot drop and paresis of the calf muscles, which can impair early postoperative mobility and weight-bearing more significantly than a distal ankle block3.
The methodology utilized to perform these blocks influences their clinical success. Historically, ankle blocks were performed using anatomic landmark-guided techniques, which rely on the physical palpation of arterial pulses and bony landmarks. However, the anatomic landmark-guided technique has been associated with variable success rates due to anatomical anomalies and the difficulty of reliably palpating vessels like the posterior tibial artery. The advent of ultrasound-guided regional anesthesia has significantly improved the reliability of these blocks.
During podiatric surgery, ultrasound-guided nerve blocks, particularly for the tibial and deep fibular nerves, allow for direct visualization of the neural structures and the precise deposition of local anesthetic. Retrospective analyses indicate that ultrasound-guided ankle blocks achieve a significantly higher rate of successful surgical anesthesia compared to landmark-guided techniques, reducing the rate of unplanned general anesthesia and the necessity for supplemental intraoperative fentanyl. Moreover, the utilization of ultrasound guidance is especially beneficial for less experienced practitioners, standardizing the overall quality of the block and decreasing the risk of inadvertent vascular puncture4.
The integration of peripheral nerve blocks into podiatric surgery represents a significant advancement in perioperative patient care. By providing targeted, long-lasting analgesia while maintaining hemodynamic stability, regional nerve blocks optimize intraoperative surgical conditions and enhance postoperative recovery.
References
1. Ravanbod, H. R. Analgesic efficacy of local versus proximal nerve blocks after hallux valgus surgery: a systematic review. J. Foot Ankle Res. 15, 78 (2022). https://doi.org/10.1186/s13047-022-00581-0
2. Lee, M. et al. Comparison of a Peripheral Nerve Block versus Spinal Anesthesia in Foot or Ankle Surgery: A Systematic Review and Meta-Analysis with a Trial Sequential Analysis. J. Pers. Med. 13, 1096 (2023). https://pmc.ncbi.nlm.nih.gov/articles/PMC10381348/
3. Moosa, F., Allan, A. & Bedforth, N. Regional anaesthesia for foot and ankle surgery. BJA Educ. 22, 424-431 (2022). https://doi.org/10.1016/j.bjae.2022.07.005
4. Chin, K. J., Wong, N. W. Y., Macfarlane, A. J. R. & Chan, V. W. S. Ultrasound-Guided Versus Anatomic Landmark-Guided Ankle Blocks: A 6-Year Retrospective Review. Reg. Anesth. Pain Med. 36, 611-618 (2011). https://doi.org/10.1097/AAP.0b013e31822b1291