UNASSIGNED: Pulsed radiofrequency (PRF) of the saphenous nerve (SN) has shown effective pain relief in knee pain because of knee osteoarthritis (KOA). The adductor canal (AC) contains other sensory nerves innervating the medial part of the knee joint apart from SN. We compared the PRF of SN within and outside the AC for their quality and duration of pain relief in knee osteoarthritis of the medial compartment (KOA-MC).
UNASSIGNED: We conducted a randomized prospective study in 60 patients with anteromedial knee pain because of KOA-MC. Patients in group A received PRF-SN, and those in group B received PRF-AC. The primary objectives were comparison of pain by Visual Analog Scale (VAS) scores and changes in quality of daily living by Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and OXFORD knee scores. The secondary objectives were comparison of analgesic requirements using Medicine Quantification Scale (MQS) scores and block-related complications. Intra-group comparison was performed by analysis of variance. Inter-group normally distributed data were assessed by Student\'s t-test, non-normally distributed and ordinal data were assessed by Mann-Whitney U-test, and categorical data were assessed by Chi-square test. A P value of <0.05 was considered significant.
UNASSIGNED: VAS scores were significantly lower in Gr-B at 12 weeks. The WOMAC scores and OXFORD scores at 4, 8, 12, and 24 weeks were significantly lower in Gr-B compared to Gr-A.
UNASSIGNED: The PRF-AC provides better pain relief and functional outcome than PRF-SN; however, duration of pain relief was not significantly different.

The optimal analgesia for total knee arthroplasty (TKA) requires excellent analgesia while preserving muscle strength. This study aimed to determine the hypothesis that continuous adductor canal block (CACB) combined with the distal interspace between the popliteal artery and the posterior capsule of the knee (IPACK) block could effectively alleviate the pain of the posterior knee, decrease opioids consumption, and promote early recovery and discharge.
Patients undergoing unilateral, primary TKA were allocated into group CACB+SHAM (receiving CACB plus sham block) or group CACB+IPACK (receiving CACB plus IPACK block). The primary outcome was cumulative opioid consumption. Secondary outcomes included the incidence of postoperative pain originated from the posterior knee, visual analogue scale (VAS) score, range of motion, ambulation distance, and satisfaction for pain management.
The incidence of moderate-severe pain of the posterior knee was lower in group CACB+IPACK than that of the group CACB+SHAM at 4 hours (17.1% vs. 42.8%; p = 0.019), 8 hours (11.4% vs. 45.7%; p = 0.001), and 24 hours (11.4% vs. 34.3%; p = 0.046) after TKA. The VAS scores of the posterior knee were lower in group CACB+IPACK than that of the group CACB+SHAM at 4 hours [2 (2) vs. 3 (2-4); p = 0.000], 8 hours [1 (1, 2) vs. 3 (2-4); p = 0.001], and 24 hours [1(0-2) vs. 2 (1-4); p = 0.002] after TKA. The overall VAS scores were lower in group CACB+IPACK than that of the group CACB+SHAM at 4 hours [3 (2, 3) vs. 3 (3, 4); p = 0.013] and 8 hours [2 (2, 3) vs. 3 (2-4); p = 0.032] at rest and 4 hours [3 (3, 4) vs. 4 (4, 5); p = 0.001], 8 hours [3 (2-4) vs. 4 (3-5); p = 0.000], 24 hours [2 (2, 3) vs. 3 (2-4); p = 0.001] during active flexion after TKA. The range of motion (59.11 ± 3.90 vs. 53.83 ± 5.86; p = 0.000) and ambulation distance (44.60 ± 4.87 vs. 40.83 ± 6.65; p = 0.009) were superior in group CACB+IPACK than that of the group CACB+SHAM in postoperative day 1. The satisfaction for pain management was higher in group CACB+IPACK than that of the group CACB+SHAM [9 (8, 9) vs. 8 (7-9); p = 0.024]. There was no difference in term of cumulative opioids consumption between group CACB+IPACK and group CACB+SHAM [120(84-135) vs. 120(75-135); p = 0.835].
The combination of CACB and distal IPACK block could decrease the incidences of moderate-severe posterior knee pain, improve the postoperative pain over the first 24 hours after TKA, as well as promoting recovery of motor function. However, the opioids consumption was not decreased by adding distal IPACK to CACB.
This study was registered at Chinese Clinical Trial Registry ( ChiCTR2200059139 ; registration date: 26/04/2022; enrollment date: 16/11/2020; http://www.chictr.org.cn ).

UNASSIGNED: Total knee replacement (TKR) surgeries are associated with significant postoperative pain. Ultrasound-guided adductor canal block is associated with better pain scores. The addition of Clonidine and Dexmedetomidine as additives to local anesthetics was the recent focus of interest. However, there are minimal studies comparing the duration of analgesia as additives to Ropivacaine in ultrasound-guided adductor canal block for TKRs.
UNASSIGNED: Prospective, randomized, double-blind design was followed. One hundred and two American Society of Anesthesiologists I to III patients undergoing unilateral TKR surgeries were included in the study and randomized into two groups. Group C received Clonidine 150 mcg and Group D received Dexmedetomidine 100 mcg as an add on to 30 mL of 0.2% ropivacaine for adductor canal block. Postoperatively, duration of analgesia, sedation score, rescue analgesic requirement, hemodynamics, and any other adverse effects were monitored.
UNASSIGNED: The total duration of analgesia in Group D (16.01 h [standard deviation [S. D]-0.5]) was significantly higher as compared to Group C (13.02 h [S. D-0.5]) (P < 0.0001). The numerical rating score (NRS) was significantly lower in Group D compared to Group C (P < 0.05) at multiple postoperative timelines. Group D (2.25(S. D-0.44)) had better sedation scores as compared to Group C (2 [S. D-0]) (P = 0.001).
UNASSIGNED: Dexmedetomidine has longer duration, lower pain, and better sedation scores as compared to clonidine in adductor canal blocks for postoperative pain relief in TKR surgeries.

BACKGROUND: Adductor canal (AC) catheters are being used to provide continuous postoperative analgesia after total knee arthroplasty (TKA) surgery. There are anatomical arguments that most AC catheters are being inserted into the femoral triangle (FT) compartment of the thigh rather than the AC compartment. The clinical relevance of this is unknown with respect to motor weakness, quality of analgesia, and opioid consumption. We hypothesised that AC catheters provide superior functional mobilisation on postoperative Day 1 after TKA as measured using the Timed Up and Go (TUG) test.
METHODS: In this multinational, multicentre, double-blinded RCT, catheters were inserted under ultrasound guidance into the anatomical AC and FT compartments. The standardised protocol included spinal anaesthesia without intrathecal morphine, fixed catheter infusion rates, and oral analgesia.
RESULTS: Of 151 subjects recruited, 75 were in the AC group and 76 in the FT group. There was no statistically significant difference in TUG on postoperative Day 1 between AC (38 [29-55] s) and FT subjects (44 [32-64] s) (median [inter-quartile range]); P=0.11). There was no difference in TUG Day 2, AC (38 [27-53] s) vs FT (42 [31-59] s); P=0.66. There were no statistically significant differences for secondary endpoints of pain level, effectiveness of pain relief, interference of functional activities and interpersonal relationships by pain, and opioid consumption between groups.
CONCLUSIONS: There were no differences in immediate postoperative functional mobility, analgesia, and opioid consumption provided by catheters inserted into the AC vs FT locations for TKA surgery.
BACKGROUND: ANZCTR12617001421325.

BACKGROUND: Peripheral nerve blocks, particularly femoral nerve blocks (FNBs), are commonly performed for anterior cruciate ligament (ACL) reconstruction. However, associated quadriceps muscle weakness after FNBs is well described and may occur for up to 6 months postoperatively. The adductor canal block (ACB) has emerged as a viable alternative to the FNB, theoretically causing less quadriceps weakness during the immediate postoperative period, as it bypasses the majority of the motor fibers of the femoral nerve that branch off proximal to the adductor canal.
OBJECTIVE: This study sought to identify if a difference in quadriceps strength exists after an ACB or FNB for ACL reconstruction beyond the immediate postoperative period. Beyond the immediate postoperative period, we anticipated no difference in quadriceps strength between patients who received ACBs or FNBs for ACL reconstruction.
METHODS: Randomized controlled trial; Level of evidence, 1.
METHODS: A total of 102 patients undergoing primary ACL reconstruction using a variety of graft types were enrolled between November 2015 and April 2016. All patients were randomized to receive an ACB or FNB before surgery, and the surgeon was blinded to the block type. All patients underwent aggressive rehabilitation without functional bracing postoperatively. The time to the first straight-leg raise was reported by the patient. Isokinetic strength testing was performed at 3 and 6 months postoperatively.
RESULTS: Data for 73 patients were analyzed. There was no significant difference in patient demographics of age, body mass index, sex, or tourniquet time between the FNB (n = 35) and ACB (n = 38) groups. The mean time to the first straight-leg raise was similar, at 13.1 ± 1.0 hours for the FNB group and 15.5 ± 1.2 hours for the ACB group (P = .134). The mean extension torque at 60 deg/s increased significantly for both the ACB (53.7% ± 3.4% to 68.3% ± 2.9%; P = .008) and the FNB (53.3% ± 3.3% to 68.5% ± 4.1%; P = .006) groups from 3 to 6 months postoperatively. There was also no significant difference in mean extension torque at 60 deg/s or 180 deg/s between the FNB and ACB groups at 3 and 6 months. There were no significant differences in postoperative complications (infection, arthrofibrosis, retear) between groups.
CONCLUSIONS: Although prior studies have shown immediate postoperative benefits of ACBs compared with FNBs, with a faster return of quadriceps strength, in the current study there was no statistically or clinically significant difference in quadriceps strength at 3 and 6 months postoperatively in patients who received ACBs or FNBs for ACL reconstruction.

BACKGROUND: Placement of local anaesthetic within the adductor canal using ultrasonography is an alternative to femoral nerve blocks for postoperative pain relief after knee joint replacement surgery. However, the effect of an inflated thigh tourniquet on the distribution of local anaesthetic within the adductor canal is unknown. The aim of this cadaveric study was to compare the distribution of radio-opaque dye within the adductor canal in the presence or absence of an inflated thigh tourniquet.
METHODS: Bilateral ultrasound-guided adductor canal blocks were performed on the thawed lower limbs of five fresh frozen human cadavers. The left and right lower cadaver limbs were randomised to receive or not receive a thigh tourniquet inflated to 300 mm Hg for 1 h. X-rays with iohexol radio-opaque dye were obtained in four views, and fiducial markers inserted as reference points. Virtual editing technology was used to recreate outlines representing the distribution of the radio-opaque dye and superimpose these on anatomical images.
RESULTS: Radio-opaque dye was distributed on the medial aspect of the thighs with entire and well circumscribed margins. The majority of the radio-opaque dye was confined within the adductor canal. Superior-inferior dye distribution was 315 mm [95% confidence intervals (CI) 289-342] and 264 mm (95% CI 239-289) in the presence and absence of an inflated thigh tourniquet, respectively (diff 95% CI -80.46 to -22.22, P=0.0081). Image analysis using the recreated radio-opaque outlines suggested that the most proximal point of the radio-opaque dye was 100 mm (95% CI 82-117) or 117 mm (95% CI 62-171) below the inguinal ligament in the presence and absence of an inflated thigh tourniquet, respectively (diff 95% CI -38 to 72, P=0.456).
CONCLUSIONS: Application and inflation of thigh tourniquets significantly increased the combined superior-inferior dye distribution within the adductor canal of cadaveric limbs. There was insufficient evidence to suggest significant proximal spread of 25 ml of local anaesthetic to involve the motor branches of the femoral nerve. In some patients, the local anaesthetic may reach the popliteal fossa in close approximation to the sciatic nerve.

OBJECTIVE: The aim of this study is to re-define the anatomical structures which are important for blocking the sciatic nerve and the nerves within the adductor canal which innervate the knee joint through the same injection site. We also aimed to investigate the spread of the anesthetic toward the areas in which the mentioned nerves lie on cadavers.
METHODS: This study was performed on 16 lower extremities of formaldehyde-embalmed eight adult cadavers. The anatomy of adductor canal, courses of the nerves within the canal and the relationships of the saphenous, medial femoral cutaneous, medial retinacular, posterior branch of the obturator and sciatic nerves with each other and with the fascial compartments were investigated. Transverse sections that crossed the superior border of vastoadductor membrane were taken to reach the sciatic nerve in the shortest way. Colored latex was injected to demonstrate the anesthetic blockage of the targeted nerves. The structures along the needle\'s way were investigated.
RESULTS: The saphenous, medial femoral cutaneous and at its distal part posterior branch of the obturator nerve were colored with latex within the adductor canal. The nerve to vastus medialis (in other words, the medial retinacular nerve) lay beneath the fascia of vastus medialis and did not enter the adductor canal. There was a fascial plane which did not allow the passage of colored latex toward the sciatic nerve. To traverse this fascial structure, it was found out to be necessary to insert the needle perpendicular to both the vertical and transverse axes of the thigh and then advance it along 2/3 of diameter of the thigh. Thus, the colored latex was observed to fill the compartment where the sciatic nerve lay within.
CONCLUSIONS: Blocking the sciatic nerve and the nerves within the adductor canal which innervate the knee joint through the same injection site seems anatomically possible without injuring any neurovascular structures.

Total knee arthroplasty (TKA) is associated with significant pain post-operatively. Our hypothesis is that adductor canal block (ACB) would be superior to local infiltration analgesia (LIA) in terms of providing analgesia, while still preserving quadriceps strength and enabling early postoperative rehabilitation.
A prospective, blinded and randomized clinical trial between LIA and ACB was conducted.
Tertiary care urban hospital.
40 patients (ASA I to III) undergoing primary TKA under single-dose spinal anesthesia were prospectively randomized from January 2014 to October 2015.
The LIA group received local infiltration of Ropivacaine 150 mg, Ketorolac 30 mg, Morphine 10 mg, and Adrenaline 200 mcg in a total volume of 75 mls, administered intraoperatively by the surgeon. The ACB group was given an ACB postoperatively by one of the study investigators at the end of surgery with 30 mls of 0.5% Ropivacaine.
The primary outcome was total Morphine consumption in the first 24 h. Secondary outcomes included total Morphine consumption in the first 48 h, pain scores, quadriceps strength, the Timed Up and Go test (TUG), the 30 s Chair Stand Test (30s-CST) and length of hospital stay.
The median (interquartile range) 24 h Morphine consumption was 6 mg (2.3-18.3) in the ACB group and 17.5 mg (12-24.3) in the LIA group, p = 0.004. The 48 h Morphine consumption was 14.5 mg (7.5-28.5) in the ACB group as compared to 24 mg (14-33.8) in the LIA group, p = 0.03. There were no statistically significant differences in the other secondary outcomes.
ACB group had statistically significant reduced total Morphine consumption in the first 24 and 48 hours as compared to LIA group, with no statistically significant differences in functional outcomes of TKA patients.

The precise description of the fascia vasto-adductoria (FVA) has become an issue of great surgical and clinical importance. Neurovascular entrapment within the adductor canal (AC) may simulate many clinical conditions for cases presented with medial knee or leg pain and ischemic manifestations of the leg. The aim of the present work is to describe the morphological features of the FVA and to elucidate its neurovascular relations. Forty thigh specimens, pertaining to 15 embalmed and five fresh adult human cadavers, were dissected in pursuit of this aim. The FVA was a continuous subsartorial fascia, roofing the whole length of AC and extended between two points lying at a mean distance of 25.6 and 7 cm proximal to the base of patella. It was subdivided into two parts; proximal thin quadrangular (proximal part of FVA) and distal thick pentagonal (vastoadductor membrane; VAM) and the subsartorial space was observed superficial to it. The mean length of its proximal and distal parts was 7.8 and 7.9 cm, respectively. The proximal part of FVA, while stretched across the vastus medialis (VM) and the adductor longus (AL) muscles, became attached to the wall of the femoral artery and overlaid the femoral vessels, the saphenous nerve (SN), and an arterial pedicle for VM muscle. It was constantly pierced by two arterial pedicles arising from the femoral artery to the sartorius muscle and occasionally (50%) by a communicating nerve branch arising from the SN to join the medial femoral cutaneous nerve. The VAM stretched across the VM muscle and both the AL and adductor magnus (AM) muscles and overlaid the SN, its subsartorial and lower medial femoral cutaneous branches, femoral vessels, 1-3 arterial pedicles for the sartorius and descending genicular vessels. The VAM originated from the tendinous fibres of the AM tendon and constantly spread anterolaterally. It was constantly pierced by 1-3 arterial pedicles to sartorius muscle and both the lower medial femoral cutaneous branch and the subsartorial branches of the SN. An arterial pedicle to the VM muscle and perforating veins between the superficial veins and the femoral vein proved to pierce it in 8/40 specimens. Entrapment of the SN at the distal narrow aperture of the AC, or one of its cutaneous branches at the piercing sites of the FVA, should be remembered when diagnosing cases presented with medial knee or leg pain. The attachment of the proximal part of the FVA to the wall of the femoral artery could add to the mechanism of its potential compression. True AC block should be done deep to the FVA to ensure effective SN analgesia. Its site is recommended to be at the distal one cm of the proximal part of the AC which is at a distance of 16-17 cm proximal to the base of patella. The VAM, being an anatomical connection between the VM and AM muscles, is theorized to increase the mechanical efficiency of the VM oblique muscle to maintain the knee extensor mechanism.