[A prospective comparative study on effectiveness of single versus continuous adductor canal block combined with local infiltration anesthesia in unicompartmental knee arthroplasty]

Objective

To compare the early analgesic effects and the impact on knee joint function recovery after unicompartmental knee arthroplasty (UKA) between single adductor canal block (SACB) and continuous adductor canal block (CACB) combined with local infiltration anesthesia (LIA) using a prospective study.

Methods

The patients with knee osteoarthritis admitted between April 2022 and December 2023 were enrolled as a subject. Among them, 60 patients met the selection criteria and were enrolled in the study. They were randomly assigned to the SACB group or CACB group in a ratio of 1:1 using a random number table method. There was no significant difference between the two groups ( P>0.05) in terms of age, gender, height, body mass, body mass index, affected side, and preoperative resting visual analogue scale (VAS) score and active VAS score, Oxford knee score (OKS), and American Hospital of Special Surgery (HSS) score. All patients received multimodal analgesia management using LIA combined with SACB or CACB. The operation time, pain related indicators (resting and activity VAS scores, number and timing of breakthrough pain, opioid consumption), joint function related indicators (quadriceps muscle strength, knee range of motion, OKS score, and HSS score), as well as postoperative block complications and adverse events were recorded and compared between the two groups.

Results

There was no significant difference in the operation time between the two groups ( P<0.05). All patients in the two groups were followed up with a follow-up time of (9.70±4.93) months in the SACB group and (12.23±5.05) months in the CACB group, and the difference was not significant ( P>0.05). The CACB group had a significant lower resting VAS score at 24 hours after operation compared to the SACB group ( P<0.05). There was no significant difference in resting and active VAS scores between the two groups at other time points ( P>0.05). The CACB group had a significantly lower incidence of breakthrough pain compared to the SACB group [9 cases (30.00%) vs. 17 cases (56.67%); P<0.05). However, there was no significant difference in the timing of breakthrough pain occurrence and opioid consumption between the two groups ( P>0.05). Four cases in the SACB group and 7 cases in the CACB group experienced adverse events, with no significant difference in the incidence of adverse events between the two groups ( P>0.05). The CACB group had significantly better knee joint mobility than the SACB group at 1 and 2 days after operation ( P<0.05). There was no significant difference between the two groups in knee joint mobility on 0 day after operation and quadriceps muscle strength and OKS and HSS scores at different time points ( P>0.05).

Conclusion

In UKA, the analgesic effects and knee joint function recovery are similar when compared between LIA combined with SACB and LIA combined with CACB. However, SACB is simpler to perform and can avoid adverse events such as catheter displacement and dislocation. Therefore, SACB may be a better choice.

Comparative Efficacy of iPACK vs Popliteal Sciatic Nerve Block for Pain Management Following Total Knee Arthroplasty: A Retrospective Analysis

Introduction Total knee arthroplasty (TKA) is associated with severe acute postoperative pain. The use of tourniquets and drains (T/D) is common in TKA but may have an influence on postoperative pain and muscular strength. The infiltration of local anesthetic between the popliteal artery and capsule of the knee (iPACK block) is a motor-sparing block that provides analgesia to the posterior aspect of the knee. However, evidence regarding its efficacy is scarce. This study aims to assess the effectiveness of iPACK block and the impact of T/D use on pain and muscular strength after TKA. Material and methods A retrospective study was carried out including patients who underwent TKA from January 2020 to April 2023. Patients were allocated into groups according to the peripheral nerve block performed and T/D use. Results We included 415 patients in this study. No differences were found in pain at rest or the need for rescue analgesia between patients who received an iPACK block or sciatic nerve block (SNB) with T/D applied. Patients who received a SNB reported lower pain scores on movement (p = 0.019), but with a higher prevalence of motor block (p < 0.001). Patients who underwent surgery without using T/D reported lower pain scores on movement (p = 0.021) and reduced need for rescue analgesia (p = 0.041). Conclusion These findings indicate that iPACK block can facilitate early mobilization after TKA without significant impact on postoperative muscle strength. Furthermore, the use of a T/D may be a source of postoperative pain that could compromise early rehabilitation.

Positioning the Catheter Tip Anterior or Posterior to the Saphenous Nerve in Continuous Adductor Canal Block: A Mono-Centric Retrospective Comparative Study

Background and Aim

Ultrasound-guided continuous adductor canal block (cACB) is a conventional choice in patients undergoing total knee arthroplasty (TKA) for the management of the postoperative pain. This study aims to compare different catheter tip locations for cACB relative to the saphenous nerve (anteriorly vs posteriorly) in terms of efficacy and complications.

Methods

At the department of Surgical Sciences, Orthopedic Trauma and Emergencies of the University of Naples Federico II (Naples, Italy), between January 2020 and November 2021, retrospective comparative study was executed. Patients planned for TKA were included in the study if they met the follow inclusion criteria: patients undergone TKA; aged 50-85 years; body mass index (BMI) of 18-35 kg/m2; American Society of Anesthesiologists (ASA) physical status classification from I to III; subarachnoid technique for anesthesiology plane; continuous adductor canal block performed by an anesthetist with considerable experience. Patients were assigned to receive cACB with the catheter tip located anteriorly (Group 1, G1) or posteriorly to the saphenous nerve (Group 2, G2). Postoperative pain, ambulation ability, episodes of pump block and rate of catheter dislodgement and leakage were evaluated and analyzed.

Results

Altogether, 102 patients were admitted to the study (48 in G1 and 54 in G2). After the first 8 postoperative hours, in G1 17 patients (35.4%) had a VAS greater than 4, while in group 2 only 3 patients (5.6%) had a VAS greater than 4 (p-value <0.01). All patients of both groups showed ambulation ability in the postoperative period. No episode of leakage was recorded. While the catheter displacement rate was similar in the two groups (2.1% for G1 vs 3.7% for G2; p-value >0.05), the episodes of pump block were significantly less in G2 than in G1 (3.7% vs 20.8%; p-value <0.01).

Conclusion

In cACB for TKA, we found that positioning the catheter tip posteriorly to the saphenous nerve may lead to a greater postoperative analgesia and reduce the risk of pump block compared to placing the catheter tip anteriorly to the nerve.

Opioid-Sparing Analgesia and Enhanced Recovery After Total Knee Arthroplasty Using Combined Triple Nerve Blocks With Local Infiltration Analgesia

BACKGROUND

Peripheral nerve block and local infiltration analgesia (LIA) have an increasing role as part of multimodal analgesia for enhanced recovery after total knee arthroplasty (TKA). We hypothesized that the combination of obturator nerve block (ONB) and tibial nerve block (TNB) would reduce pain and opioid consumption more than ONB or TNB alone when combined with continuous adductor canal block and LIA.

METHODS

Ninety patients were recruited into the study and received spinal anesthesia, LIA, and continuous adductor canal block. They were further randomized to receive either an ONB (group 1), a TNB (group 2), or both (group 3). The primary outcome was total morphine consumption over the postoperative 24 hours. The secondary outcomes included visual analog scale scores, time to first and total dosage of rescue analgesia, Timed Up and Go test, range of motion, muscle strength test, hospital stay, and patient satisfaction.

RESULTS

Eighty-nine patients completed analysis. The median total morphine consumption during the first 24 postoperative hours was 2 mg (interquartile range [IQR] 0-4) in group 3, 4 mg (IQR 2-8) in group 2, and 6 mg (IQR 6-14) in group 1 (P < .001). Posterior knee pain during the first 24 hours postoperatively was significantly lower in group 3 than in group 1 (P = .006). The ability to ambulate and quadriceps strength were significantly better in group 3 than in the other groups.

CONCLUSION

The combination of triple nerve block was superior to double nerve block in improving analgesia and functional outcomes in the immediate postoperative period after total knee arthroplasty, when combined with LIA.

A randomized comparison of proximal and distal ultrasound-guided adductor canal catheter insertion sites for knee arthroplasty

OBJECTIVES

Proximal and distal (mid-thigh) ultrasound-guided continuous adductor canal block techniques have been described but not yet compared, and infusion benefits or side effects may be determined by catheter location. We hypothesized that proximal placement will result in faster onset of saphenous nerve anesthesia, without additional motor block, compared to a distal technique.

METHODS

Preoperatively, patients receiving an ultrasound-guided nonstimulating adductor canal catheter for knee arthroplasty were randomly assigned to either proximal or distal insertion. A local anesthetic bolus was administered via the catheter after successful placement. The primary outcome was the time to achieve complete sensory anesthesia in the saphenous nerve distribution. Secondary outcomes included procedural time, procedure-related pain and complications, postoperative pain, opioid consumption, and motor weakness.

RESULTS

Proximal insertion (n = 23) took a median (10th-90th percentiles) of 12.0 (3.0-21.0) minutes versus 6.0 (3.0-21.0) minutes for distal insertion (n = 21; P= .106) to anesthetize the medial calf. Only 10 of 25 (40%) and 10 of 24 (42%) patients in the proximal and distal groups, respectively, developed anesthesia at both the medial calf and top of the patella (P= .978). Bolus-induced motor weakness occurred in 19 of 25 (76%) and 16 of 24 (67%) patients in the proximal and distal groups (P = .529). Ten of 24 patients (42%) in the distal group required intravenous morphine postoperatively, compared to 2 of 24 (8%) in the proximal group (P = .008), but there were no differences in other secondary outcomes.

CONCLUSIONS

Continuous adductor canal blocks can be performed reliably at both proximal and distal locations. The proximal approach may offer minor analgesic and logistic advantages without an increase in motor block.