PURPOSE: We compared a single-injection adductor canal block (ACB) with or without local infiltration analgesia (LIA) for accelerating functional recovery and reducing postoperative pain after total knee arthroplasty (TKA). MATERIALS AND METHODS: Sixty-two patients undergoing TKA with simple spinal analgesia and ACB were randomized to receive either LIA (group A+L) or placebo LIA (group A). Postoperative visual analog scale (VAS) score for pain, Timed Up and Go (TUG) test and quadriceps strength, total dosage of rescue analgesia, time to first rescue analgesia, and adverse events were serially evaluated from postoperative day 1 to 3 months. RESULTS: There were no differences between both groups in pre- and postoperative VAS, TUG test, quadriceps strength 2 days, 3 days, 2 weeks, 6 weeks, and 3 months postoperatively. There were no differences in Knee Society clinical and function scores at 6 months and 1 year. However, group A+L had a significantly longer time for postoperative rescue analgesia (491 minutes vs. 143 minutes, p=0.04) with less patients requiring rescue analgesia during 6 hours after surgery (16.7% vs. 43.3%, p=0.024). Both groups had similarly high rates of patient satisfaction with low adverse event rates. CONCLUSIONS: Combined ACB and LIA in TKA enhanced early ambulation with reduced and delayed rescue analgesia.
Analgesia ; Arthroplasty ; Arthroplasty, Replacement, Knee ; Early Ambulation ; Humans ; Knee ; Pain, Postoperative ; Patient Satisfaction ; Visual Analog Scale ; Walking

BACKGROUND: This study aimed to determine the optimal location of local anesthetic injection in the interspace between the popliteal artery and posterior capsule of the knee (iPACK), using the anatomical pattern of the articular branch of tibial nerve (ABTN). We hypothesized that injection at the level of ABTN forming a popliteal plexus would mainly spread throughout the popliteal fossa without contacting the tibial or peroneal nerves. METHODS: The anatomical study included 30 soft cadavers. Ultrasound-guided dye injection was performed in legs of 10 cadavers after identifying the position of the ABTN and surrounding structures, followed by dissection to assess its spread. Clinical study was conducted in 15 patients undergoing total knee arthroplasty (TKA) with ultrasound-guided injection in the iPACK. All patients also received continuous adductor canal block. Sensorimotor function of the tibial and common peroneal nerves was determined. RESULTS: In the distal portion of the popliteal fossa, the tibial nerve and popliteal vessels ran superficially and closely together. The trajectory of ABTN ran lateral to the popliteal vasculature, forming a plexus towards the posterior capsule of the knee below the medial side of the upper edge of lateral femoral condyle. In cadavers, the ABTN and surrounding area of the popliteal plexus were stained with dye after injection. In the clinical study, no patients experienced complete motor or sensory blocks. CONCLUSIONS: We described a modified iPACK technique injection at the level of the ABTN forming the popliteal plexus, and it may constitute an optional anesthetic regimen to promote early ambulation following TKA.
Arthroplasty, Replacement, Knee ; Cadaver ; Clinical Study ; Early Ambulation ; Humans ; Knee ; Leg ; Pain, Postoperative ; Peroneal Nerve ; Popliteal Artery ; Tibial Nerve

BACKGROUND: This study aimed to determine the optimal location of local anesthetic injection in the interspace between the popliteal artery and posterior capsule of the knee (iPACK), using the anatomical pattern of the articular branch of tibial nerve (ABTN). We hypothesized that injection at the level of ABTN forming a popliteal plexus would mainly spread throughout the popliteal fossa without contacting the tibial or peroneal nerves. METHODS: The anatomical study included 30 soft cadavers. Ultrasound-guided dye injection was performed in legs of 10 cadavers after identifying the position of the ABTN and surrounding structures, followed by dissection to assess its spread. Clinical study was conducted in 15 patients undergoing total knee arthroplasty (TKA) with ultrasound-guided injection in the iPACK. All patients also received continuous adductor canal block. Sensorimotor function of the tibial and common peroneal nerves was determined. RESULTS: In the distal portion of the popliteal fossa, the tibial nerve and popliteal vessels ran superficially and closely together. The trajectory of ABTN ran lateral to the popliteal vasculature, forming a plexus towards the posterior capsule of the knee below the medial side of the upper edge of lateral femoral condyle. In cadavers, the ABTN and surrounding area of the popliteal plexus were stained with dye after injection. In the clinical study, no patients experienced complete motor or sensory blocks. CONCLUSIONS We described a modified iPACK technique injection at the level of the ABTN forming the popliteal plexus, and it may constitute an optional anesthetic regimen to promote early ambulation following TKA.

Background: Ultrasound-guided femoral triangle block (FTB) can provide motor-sparing anterior knee analgesia. However, it may not completely anesthetize the anterior femoral cutaneous nerve (AFCN). We hypothesized that an AFCN block (AFCNB) in combination with an FTB would decrease pain during movement in the immediate 12 h postoperative period compared with an FTB alone. Methods: Eighty patients scheduled to undergo total knee arthroplasty were randomized to receive either FTB alone (FTB group) or AFCNB with FTB (AFCNB + FTB group) as part of the multimodal analgesic regimen. The primary outcome was pain during movement at 12 h postoperatively. Secondary outcomes included numeric rating scale (NRS) pain scores, incidence of surgical incision site pain, intravenous morphine consumption, immediate functional performance, patient satisfaction, and length of hospital stay. Results: The NRS pain scores on movement 12 h postoperatively were significantly lower in the AFCNB + FTB group than in the FTB group (mean difference: –2.02, 95% CI: –3.14, –0.89, P < 0.001). The incidence of pain at the surgical incision site at 24 h postoperatively and morphine consumption within 48 h postoperatively were significantly lower (P < 0.001), and quadriceps muscle strength at 0° immediately after surgery was significantly greater in the AFCNB + FTB group (P = 0.04). Conclusions The addition of ultrasound-guided AFCNB to FTB provided more effective analgesia and decreased opioid requirement compared to FTB alone after total knee arthroplasty and may enhance immediate functional performance on the day of surgery.