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HSS-led Consensus Recommends Peripheral Nerve Blocks for Joint Replacement to Improve Outcomes

Statement from the International Consensus on Anesthesia Related Outcomes after Surgery (ICAROS) Group, Pt. 2

Collaborators from Hospital for Special Surgery (HSS) and partners around the globe have strongly recommended the use of peripheral nerve blocks during total hip arthroplasty (THA) and total knee arthroplasty (TKA) for improved outcomes. While nearly 99% of patients undergoing TKA at HSS receive a nerve block, the average in the United States is only about 1 in 4, according to Stavros G. Memtsoudis, MD, PhD, MBA, an anesthesiologist in the Department of Anesthesiology, Critical Care & Pain Management at HSS and leader of the project.

These recommendations were created in a follow-up project conducted after the first recommendations made by the ICAROS group in 2019. ICAROS part 2 included a systematic review and meta-analysis of 122 studies comprising more than 1 million cases, investigating how the use of peripheral nerve blocks correlated to major complications such as mortality as well as cardiac, pulmonary, gastrointestinal, renal, thromboembolic, neurologic, infectious, and bleeding complications.

ICAROS part 1 examined the impact of the choice of anesthetic technique for surgery, and experts determined that the evidence suggested that neuraxial anesthesia was associated with better outcomes in joint arthroplasty patients compared to general anesthesia,” said Dr. Memtsoudis. “Part 2 concerns itself with another aspect of regional anesthesia procedures commonly performed for postoperative pain management, namely peripheral nerve blocks. Neuraxial anesthesia is temporary and provides conditions to perform surgery. Peripheral nerve blocks are longer-acting and are being used for pain control.”

“This work is of utmost importance as it provides evidence-based recommendations that improve patient outcomes if implemented widely. Currently, only a minority of patients receive these nerve blocks in the setting of joint arthroplasty,” Dr. Memtsoudis said.

Analysis showed that use of peripheral nerve blocks during surgery in comparison with no peripheral nerve block resulted in a significantly lower risk of complications (95% confidence interval), including: 70% reduced odds of cognitive dysfunction in THA, 48% reduced odds in TKA; 64% reduced odds of respiratory failure in THA, 63% reduced odds in TKA; 16% reduced odds of cardiac complications in THA, 17% reduced odds in TKA; 45% reduced odds of surgical site infections in THA, 14% reduced odds in TKA; 26% reduced odds of thromboembolism in THA, 10% reduced odds in TKA; and 16% reduced odds of blood transfusion in THA, 14% reduced odds in TKA.

Based on these findings, the international consensus group of practitioners strongly recommend that peripheral nerve blocks be used during total hip and total knee replacement surgeries for improved outcomes, except when contraindications prevent their use. Other factors that institutions should consider when determining anesthetic techniques include the skills of providers and the resources available at a given practice location.

“The group assembled and the process used to analyze the literature and come up with these recommendations has been of the highest quality,” Dr. Memtsoudis noted. “The data spoke for itself, thus making it easy for the experts to draw conclusions and make recommendations. These recommendations are solidly founded on evidence and will hopefully affect change worldwide to improve patient outcomes for millions of patients undergoing hip and knee arthroplasty. It will hopefully also lead to more research, such as which specific nerve blocks are best for which patients.”

Adds Dr. Memtsoudis, “We are contemplating expansion of our work to include other patient populations such as pediatric patients as well as other procedures once the pandemic related restrictions are behind us.”


Memtsoudis SG, Cozowicz C, Bekeris J, Bekere D, Liu JB, Soffin E, et al. “Peripheral nerve block anesthesia/analgesia for patients undergoing primary hip and knee arthroplasty recommendations from the International Consensus on Anesthesia-Related Outcomes after Surgery (ICAROS) group based on a systematic review and meta-analysis of current literature.” Reg Anesth Pain Med. 2021;0:1-15. doi:10.1136/rapm-2021-102750

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 14th consecutive year), No. 2 in rheumatology by U.S. News & World Report (2023-2024), and the best pediatric orthopedic hospital in NY, NJ and CT by U.S. News & World Report “Best Children’s Hospitals” list (2023-2024). In a survey of medical professionals in more than 20 countries by Newsweek, HSS is ranked world #1 in orthopedics for a fourth consecutive year (2023). Founded in 1863, the Hospital has the lowest readmission rates in the nation for orthopedics, and among the lowest infection and complication 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. In addition, more than 200 HSS clinical investigators are working to improve patient outcomes through better ways to prevent, diagnose, and treat orthopedic, rheumatic and musculoskeletal diseases. 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 165 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.