Table 1. Characteristics of included studies.
| Study details | Arms included (#) | Alone | Combined | Characteristics | Other analgesics used |
| Goytizolo et al23 2019USA | LIA alone (56) vs combination (55) | Deep: bupivacaine (30 mL, 0.5%) with epinephrine, morphine (1 mL, 8 mg/mL), methyl-prednisolone (1 mL, 40 mg/mL), cefazolin (500 mg, 10 mL), normal saline solution (22 mL) Superficial: bupivacaine (20 mL, 0.25%) | Ultrasound-guided ACB: bupivacaine (15 mL, 0.25%), preservative-free dexamethasone (2 mg)LIA: as described | Age: 65 (10) vs 67 (7)ASA: I - 3 vs 1; II - 51 vs 51; III - 2 vs 3Female/male: 33/23 vs 34/21 | Preoperative: oral meloxicam and extended-release oxycodone (10 mg). Spinal anaesthetic. Ondansetron (4 mg) and famotidine (20 mg) |
| Luo et al25 2022China | LIA alone (30) vs combination (30) | LIA: ropivacaine (200 mg), morphine (10 mg), betamethasone (5 mg), diluted normal saline (60 mL). Pre-implantation and post-implantation LIA performed around all relevant structures | Ultrasound-guided ACB: after general anaesthesia before skin incision ropivacaine (0.5%) or normal saline (20 mL). LIA as described | Age: 65.3 (4.86) vs 65.4 (5.22)ASA: I - 0 vs 0; II - 25 vs 24; III - 5 vs 6Female/male: 22/8 vs 23/7 | Parecoxib 20 mg two times a day immediately after the operation until discharge, oxycodone or morphine when immediate pain >4 on a 0–10 VAS was reported |
| Grosso et al24 2018USA | LIA alone (54) vs ACB alone (55) vs combination (54) | LIA: bupivacaine (50 mL, 0.25%). A standard protocol was followed. Tissues and subcutaneous tissues. Ultrasound-guided ACB: performed in the preoperative block area by the anaesthesia team prior to surgery using bupivacaine (15 mL, 0.5%) | Combined as described | Age: 73 vs 69 vs 71ASA: NRFemale/male: 39/34 vs 33/36 vs 32/19 | Preoperative: acetaminophen, oxycodone, celecoxib and gabapentin, 1 hour priorPostoperative: included acetaminophen, ketorolac then celecoxib (3 months), gabapentin (10 days), oral opioids (as needed) and intravenous hydromorphone |
| Zhou et al32 2018China | LIA alone (20) vs ACB alone (20) vs combination (20) | LIA: ropivacaine (100 mL, 2 mg/mL) with epinephrine (0.5 mL, 1 mg/mL) in two 50 mL syringes. Ultrasound-guided ACB: ropivacaine (30 mL, 0.375%), epinephrine (5 µg/mL), 21-gauge needle | Combined as described | Age: 69 (7.1) vs 67.1 (10.2) vs 66.4 (5.8)ASA: not reportedFemale/male: 16/4 vs 14/6 vs 13/7 | All subjects received a standardised general anaesthesia |
| Rajkumar et al22 2021India | LIA alone (50) vs ACB alone (50) vs combination (50) | LIA: administered by a single operating surgeon for all the patients. Ropivacaine (30 mL, 0.5%) in normal saline (20 mL) was injected around periarticular structures Ultrasound-guided ACB: after skin closure, an anaesthetist ropivacaine (30 mL, 0.2%), dexamethasone (8 mg). | Combined as described | Age: 62.24 (5.76) vs 65.2 (6.16) vs 64.88 (7.58)ASA: not reportedFemale/male: 38/12 vs 34/16 vs 36/14 | All the patients received the same pre-emptive analgesia |
| Nicolino et al29 2020Argentina | LIA alone (36) vs combination (34) | LIA: posterior capsule (30 mL), medial femoral (10 mL), lateral periosteum on each side (10 mL) and tibial periosteum (10 mL). Ropivacaine (20 mL, 0.75%), of morphine (8 mg, 1 mg/mL in 0.3 mL epinephrine), prednisolone (40 mg), saline solution (30 mL). A 16G abbocath was used. Sham ACB: internal saphenous nerve was infiltrated with saline (5 mL). | Ultrasound-guided ACB: regional SNB with ropivacaine (5 mL, 0.75%) and lidocaine (5 mL,2%) was administered by the anaesthetist.LIA: as described | Age: 72.58 (8.41) vs 71.97 (6.86)ASA: not reportedFemale/male: 27/9 vs 23/11 | Epidural anaesthesia of bupivacaine (15–20 mg, 5%), combined with midazolam sedation |
| Atchabahian et al20 2019USA | LIA alone (28) vs combination (23) | LIA: bupivacaine, ketorolac, epinephrine and morphine, as well as liposomal bupivacaine | ACB: mid-thigh level with bupivacaine (30 mL, 0.25%) with 1:200 000 epinephrine and LIA performed as described | Age: 64.0 (7.4) vs 63.5 (8.1)ASA: I - 1 vs 0; II - 16 vs 14; III - 11 vs 9Female/male: 18/10 vs 19/4 | Spinal anaesthetic and postoperative pain management were standardised |
| Rauf49 2013Ireland | LIA alone (10) vs combination (10) | No description provided | No description provided | Age: NRASA: NRFemale/male: NR | Spinal anaesthesia+/−sedation |
| Wang et al31 2019China | LIA alone (48) vs combination (48) | LIA: 20 mL cocktail (0.2% ropivacaine and 2.0 mg/mL of epinephrine). Infiltration of the collateral ligaments before implantation. After, infiltration of quadriceps and retinacular tissues with 20 mL, fat and subcutaneous tissues with 40 mL. Sham ACB: isotonic saline (20 mL) | Ultrasound-guided ACB: A 22-gauge, 100 mm needle was used to inject 20 mL of 0.2% ropivacaine and 2.0 mg/mL of epinephrine | Age: 64.0 (6.7) vs 64.8 (7.0)ASA: I - 1 vs 2; II - 30 vs 29; III - 14 vs 14Female/male: 33/12 vs 30/15 | Preoperative: loxoprofen (60 mg) two times a day Postoperative: loxoprofen (60 mg), prolonged-release oxycodone hydrochloride tablets (10 mg) were administered two times a day to control postoperative pain |
| Tziona et al28 2018Greece | ACB alone (20) vs combination (20) | Ultrasound-guided ACB: ropivacaine (25 mL, 0.375%) and dexamethasone (8 mg) before start of the surgery. Sham LIA: normal saline (0.9%,120 mL) | ACB: As describedLIA: ropivacaine (250 mg) and epinephrine (0.5 mg) in normal saline (0.9%),120-mL solution of ropivacaine (0.2%) | Age: 71.5 (8.5) vs 72.0 (7.2)ASA: I - 3 vs 2; II - 14 vs 14; III - 16 vs 15Female/male: 16/4 vs 15/5 | Preoperative: pregabalin (75 mg) per os 1 hour before surgery |
| Sawhney et al27 2016Canada | LIA alone (54) vs ACB (51) alone vs combination (54) | Ultrasound-guided ACB: under conscious sedation with fentanyl 50 µg and midazolam 1 mg. Subcutaneous injection of lidocaine (2 mL,1%) to anaesthetise the AC site. Ropivacaine (30 mL,0.5%) was injected into the canal. Sham ACB: the procedure stopped after they received lidocaine. LIA: a blinded 110 mL solution bag was prepared by the pharmacy and delivered to the operating room - ropivacaine (300 mg), morphine (10 mg) and ketorolac (30 mg) or saline (110 mL, 0.9%) | Combined as described | Age: 67.6 (9.4) vs 66.4 (9.6) vs 68.3 (9.7)ASA: NRFemale/male: 36/18 vs 31/20 vs 33/21 | Premedication: acetaminophen (1000 mg), celecoxib (200 mg), gabapentin (300 mg) |
| Biswas et al21 2018Canada | LIA alone (65) vs combination (69) | LIA: ropivacaine (150 mL, 0.2%), ketorolac (30 mg), epinephrine (0.6 mg). Half in the posterior capsule and posterior soft tissues of the knee under direct vision after osteotomy but before insertion of the implants. Half of the solution was administered into the anterior soft tissues after placement of the implants and before skin closure.Sham ACB: 30 mL of placebo solution (0.9% NaCl) with method as described for ACB | Ultrasound-guided ACB: A mid-ACB was used to block the saphenous and the nerve to vastus medialis. Lidocaine (1–2 mL, 2%) skin infiltration. The study solution was injected deep to the vastoadductor membrane (ropivacaine, 30 mL, 0.5% with 1:400 000 epinephrine) | Age: 64.2 (8.1) vs 64.2 (8.2)ASA: NRFemale/male: 41/21 vs 37/31 | Preoperative: immediately preoperatively sedation was achieved with intravenous midazolam (1–2 mg) and intravenous fentanyl (25–50 µg) as needed.Postoperative: acetaminophen (3–4 g daily up to 5 days), celecoxib (100–200 mg two times a day up to 5 days), or an NSAID drug, and hydromorphone (1–2 mg), or oxycodone (5–10 mg) every 2 hours as needed. Intravenous patient-controlled analgesia with hydromorphone or morphine was prescribed as a ‘rescue’ modality if oral analgesics failed to achieve an NRS of <5 |
| Nader et al26 2016USA | LIA alone (20) vs combination (20) | LIA: 100 mL of ropivacaine (200 mg), morphine (4 mg), ketorolac (30 mg), clonidine (100 µg) and epinephrine (0.5 mg) as part of the multimodal analgesia regimenSham ACB: normal saline (10 mL) | Ultrasound-guided ACB: bupivacaine (10 mL, 0.25%) with epinephrine 1:300 000LIA: as described | Age: 67 (59–72) vs 68ASA: NRFemale/male: 13/7 vs 15/5 | Preoperative: oxycodone (10 mg), celecoxib (400 mg). Spinal anaesthesia: bupivacaine (2.5 mL, 0.5%). Postoperative: ketorolac (15 mg every 12 hours for 24 hours), hydrocodone (10 mg), acetaminophen (325 mg 4–6 hourly) as needed to maintain a pain NRS of ≤4. Oxycodone (10 mg) every 12 hours as needed for NRS >4Breakthrough pain: intravenous hydromorphone (0.5 mg) or tramadol (50 mg) |
ACBadductor canal blocksLIAlocal infiltration analgesiaNRnot reported