Background and objectives Femoral triangle block and local infiltration analgesia are two effective analgesic techniques after anterior cruciate ligament reconstruction. Recently, the iPACK block (infiltration between the popliteal artery and the capsule of the posterior knee) has been described to relieve posterior knee pain. This randomized controlled triple-blinded trial tested the hypothesis that the combination of femoral triangle block and iPACK provides superior analgesia to local infiltration analgesia after anterior cruciate ligament reconstruction.
Methods Sixty patients undergoing anterior cruciate ligament reconstruction received general anesthesia and were randomly allocated to two groups: femoral triangle block and iPACK under ultrasound guidance or local infiltration analgesia. For each group, a total of 160 mg of ropivacaine was injected. Postoperative pain treatment followed a predefined protocol with intravenous morphine patient-controlled analgesia, acetaminophen, and ibuprofen. The primary outcome was cumulative intravenous morphine consumption at 24 hours postoperatively. Secondary pain-related outcomes included pain scores (Numeric Rating Scale out of 10) measured at 2 and 24 hours postoperatively. Functional outcomes, such as range of motion and quadriceps strength, were also recorded at 24 postoperative hours, and at 4 and 8 postoperative months.
Results Cumulative intravenous morphine consumption at 24 hours postoperatively was significantly reduced in the femoral triangle block and iPACK group (femoral triangle block and iPACK: 9.7 mg (95% CI: 6.7 to 12.7); local infiltration analgesia: 17.0 mg (95% CI: 11.1 to 23.0), p=0.03). Other pain-related and functional-related outcomes were similar between groups.
Conclusions The combination of femoral triangle block and iPACK reduces intravenous morphine consumption during the first 24 hours after anterior cruciate ligament reconstruction, when compared with local infiltration analgesia, without effect on other pain-related, early, or late functional-related outcomes.
Trial registration number ClinicalTrials.gov Registry (NCT03680716).
- postoperative pain
- anterior cruciate ligament reconstruction
- peripheral nerve block
- local infiltration analgesia
Data availability statement
Data are available upon reasonable request. Data will be shared following email request.
Statistics from Altmetric.com
Contributors RM—study design, patient recruitment and manuscript preparation. KRK—manuscript preparation. THNN—manuscript preparation. EG—data collection and table preparation. JL—manuscript preparation. EA—study design, study registration, statistical analysis, data interpretation and manuscript preparation.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests EA has received grants from the Swiss Academy for Anaesthesia Research (SACAR), Lausanne, Switzerland (SFr50 000; no grant number attributed), from B Braun Medical (SFr56 100; no grant number attributed) and from the Swiss National Science Foundation to support his clinical research (SFr353 408; grant number: 32003B_169974/1). EA has also received an honorarium from B Braun Medical, Sintetica UK and MSD. No interest declared by the other authors.
Provenance and peer review Not commissioned; externally peer reviewed.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.