A pilot study conducted at Hospital for Special Surgery (HSS) shows evidence that a mid-calf nerve block is a safe and effective regional anesthetic option for foot and ankle surgeries and may enable faster recovery of motor function of the ankle joint compared with a popliteal block. These findings were presented at the 2023 Spring American Society of Regional Anesthesia and Pain Medicine (ASRA) Annual Meeting.1
“This new block provides excellent anesthesia and analgesia to foot and ankle surgeries and preserves motor function of the ankle joint. The results are very promising,” said Enrique A. Goytizolo, MD, an anesthesiologist at HSS and senior author of the study. “New protocols of early rehabilitation of foot surgeries can be instituted, since patients have no pain with movement of the foot.”
An ultrasound-guided popliteal block is the current standard anesthetic technique for foot and ankle surgeries, but the study findings show that using an ultrasound-guided mid-calf block could enable earlier rehabilitation protocols and an overall faster recovery from surgery.
A popliteal block numbs the sciatic nerve at the level of the popliteal fossa, which is a diamond-shaped space behind the knee joint. A mid-calf block is placed farther down the leg, between the popliteal fossa and the ankle, and numbs the posterior tibial nerve, superficial and deep peroneal nerves, sural, and saphenous nerves. A mid-calf block provides prolonged analgesia for any foot or ankle surgery while preserving motor function of the ankle joint.
Twenty patients who were scheduled to receive foot or ankle surgery at HSS were recruited for the study. The procedures included total ankle replacement, ankle arthroscopy, bunionectomy, cheilectomy, and Achilles tendon repair. Participants were assessed in the post-anesthesia care unit (PACU) and again before discharge to record the time when the mid-calf block ended, presence of paresthesia, and any other side effects. On postoperative days 1, 2, and 7, participants were asked about their pain on a numerical rating score (NRS), their medication use, and other symptoms.
The researchers found that the median duration of analgesia from the mid-calf block was 18.2 hours, with an interquartile range of 4.5-24.0 hours. All 20 patients were able to flex their toes in the PACU.
The average pain score in the PACU was 0.8 +/- 2.1 at rest, and 1.1 +/- 2.3 with movement. Three participants were excluded for sensitivity analysis because they received additional surgery in surgical areas not covered by the mid-calf block. Among the 17 patients in the sensitivity analysis group, these scores were both 0.3 +/- 1.2 at rest and with movement.
“The mid-calf block provides reliable, consistent, and excellent anesthesia and analgesia for foot and ankle surgeries,” said Dr. Goytizolo. “Follow-up research and patient treatments following this study should include a fast-track rehabilitation program for patients who have total ankle replacement surgeries with a mid-calf block.”
The findings of this study will also inform future randomized control trials on the mid-calf block.
References
- Marko Popovic BS, Alex Illescas MPH, Pa Thor PhD, Jacques YaDeau MD PhD, Constantine Demetracopoulos MD, Scott Ellis MD, Vincent LaSala MD, Matthew Roberts MD, Anne H. Johnson MD, Mark Drakos MD, Enrique Goytizolo MD. “Mid-Calf Block for foot and ankle surgery: A pilot study.” Presented at: 48th Annual Regional Anesthesiology and Acute Pain Medicine Meeting of the American Society of Regional Anesthesia and Pain Medicine (ASRA), April 20-22, 2023; Hollywood, FL.
About HSS
HSS is the world’s leading academic medical center focused on musculoskeletal health. At its core is Hospital for Special Surgery, nationally ranked No. 1 in orthopedics (for the 13th consecutive year), No. 3 in rheumatology by U.S. News & World Report (2022-2023), and the best pediatric orthopedic hospital in NY, NJ and CT by U.S. News & World Report “Best Children’s Hospitals” list (2022-2023). In a survey of medical professionals in more than 20 countries by Newsweek, HSS is ranked world #1 in orthopedics for a third consecutive year (2023). Founded in 1863, the Hospital has the lowest complication and readmission rates in the nation for orthopedics, and among the lowest infection rates. HSS was the first in New York State to receive Magnet Recognition for Excellence in Nursing Service from the American Nurses Credentialing Center five consecutive times. An affiliate of Weill Cornell Medical College, HSS has a main campus in New York City and facilities in New Jersey, Connecticut and in the Long Island and Westchester County regions of New York State, as well as in Florida. In addition to patient care, HSS leads the field in research, innovation and education. The HSS Research Institute comprises 20 laboratories and 300 staff members focused on leading the advancement of musculoskeletal health through prevention of degeneration, tissue repair and tissue regeneration. The HSS Innovation Institute works to realize the potential of new drugs, therapeutics and devices. The HSS Education Institute is a trusted leader in advancing musculoskeletal knowledge and research for physicians, nurses, allied health professionals, academic trainees, and consumers in more than 145 countries. The institution is collaborating with medical centers and other organizations to advance the quality and value of musculoskeletal care and to make world-class HSS care more widely accessible nationally and internationally. www.hss.edu.
