The rates of knee surgeries continue to rise globally [1]. Appropriate pain management is paramount to ensure the best possible patient outcomes, especially since orthopedic surgeries are associated with relatively high levels of discomfort. Peripheral nerve block is a critical tool for pain management during and after knee surgery.
For a peripheral nerve block focused on the knee, an anesthesiologist administers an anesthetic near the nerves of the knee. The block lasts about 24 hours following surgery. Most patients experience the most pain following a knee replacement in the first 24 hours postoperatively. A peripheral nerve block, in addition to oral or intravenous pain medications, thus maximizes a patient’s relief during this early recovery phase. Even with a nerve block, however, a patient will usually still experience some pain and discomfort [2].
The anesthesiologist pinpoints the location of the nerve and injects the anesthetic medication near the nerve. The process takes 10 minutes and is not painful. The patient will experience a certain degree of pain relief within the first 15 to 20 minutes, with the full effect taking place within 30 minutes. The nerve block may be performed at the beginning of the knee surgery, as part of the anesthetic regimen for the OR, or after surgery, to focus on postoperative pain relief.
A peripheral nerve block is recommended for people undergoing knee replacement surgery for pain management purposes. Patients who get peripheral nerve blocks experience pain relief, and are able to rely less on opioid medications, participate more in rehabilitation therapy, and be more active after surgery, thereby lowering their risk of surgical complications like blood clots.
A recent study from 2022 sought to further investigate the use of nerve blocks for perioperative total knee arthroplasty analgesia [4]. Overall, the data demonstrated that the safety profile varies depending on which block is used, but the data suggests that an optimally chosen and administered peripheral nerve block may provide an extremely safe and effective solution for perioperative analgesia.
A patient will experience numbness in their leg after waking up from knee surgery alongside pain relief until peripheral nerve block eventually wears off. The nerve block does not affect your strength, but if a patient experiences thigh weakness, it is important to tell a clinician. It is also critical to follow explicit instructions from the clinical team with regard to walking and standing again.
Peripheral nerve blocks are considered a safe option for almost all patient, and complications from peripheral nerve blocks remain extremely rare. These include but are not limited to a risk of infection or bleeding at the injection site, seizures, abnormal heart rhythms, and prolonged thigh numbness [2].
Imaging technologies have recently become even more advanced, increasing the feasibility of using a nerve block for pain management in knee surgery. Newer equipment and improved ultrasound imaging, as well as the decreased cost of equipment, are rendering nerve blocks more and more accessible. This is increasingly allowing clinicians to address pain more effectively. Moreover, it significantly reduces the side effects of traditional pain medications, including nausea and sedation, speeding up patient recovery [3].
References
1. Nham, F. H., Patel, I., Zalikha, A. K. & El-Othmani, M. M. Epidemiology of primary and
revision total knee arthroplasty: analysis of demographics, comorbidities and outcomes from the national inpatient sample. Arthroplasty (2023). doi:10.1186/s42836-023-00175-6
2. Peripheral Nerve Block for Knee Replacement Surgery | University of Utah Health. Available at: https://healthcare.utah.edu/orthopaedics/specialties/joint-replacement/knee-replacement/peripheral-nerve-block. (Accessed: 7th January 2024)
3. Innovative Nerve Blocks Ease Pain & Impact From Knee Replacements. Available at: https://www.orlandoortho.com/innovative-nerve-blocks-ease-pain-impact-from-knee-replacements/. (Accessed: 7th January 2024)
4. Hasegawa, M. et al. Review on Nerve Blocks Utilized for Perioperative Total Knee Arthroplasty Analgesia. Orthop. Rev. (Pavia). 14, 2022 (2022). doi: 10.52965/001c.37405