Abstract Background This systematic review evaluates the use of single-shot adductor canal block (ACB) as a pain management strategy following total knee arthroplasty (TKA). The outcome of interest was to compare the different drugs used in single-shot ACB using visual analogue scale (VAS) values during the first postoperative days. Methods The present systematic review followed the 2020 PRISMA guidelines. PubMed, EMBASE, and Web of Science were accessed in May 2025 without additional filters or temporal constraints. All clinical studies concerning single-shot ACB for pain management following TKA were considered. Studies on unicompartmental knee arthroplasty and revision settings were not included. Only studies reporting data on the VAS during the postoperative days were included. Results Data from 15 RCTs were retrieved. The drugs included in the analyses were levobupivacaine, bupivacaine and ropivacaine in isolation or combined with clonidine or butorphanol. A statistically significant difference was found in VAS during activity in post-operative day (POD) 2 ( P < 0.01): the bupivacaine group demonstrated the highest values, and the group receiving ropivacaine had the lowest values. No other statistically significant difference in VAS during activity was found for any group in POD 0 and 1 ( P = 0.3 and P = 0.1, respectively). No statistically significant difference was found in VAS at rest values between any group in POD 0 ( P = 0.3), POD 1 ( P = 0.1), and POD 2 ( P = 0.5). Conclusions Single shot ACB offers adequate analgesia with a potentially motor-sparing profile following total knee arthroplasty, facilitating early mobilisation and reducing opioid consumption. The addition of adjuvants such as dexmedetomidine, dexamethasone, and clonidine may further enhance analgesic duration, though their use requires standardisation and ongoing safety monitoring. While single shot ACB is a strong candidate for routine inclusion in multimodal analgesia protocols, further research is necessary to optimise its application and evaluate long-term outcomes.
Pappalardo et al. (Sat,) studied this question.