Nerve Block Techniques for Postoperative Pain from Knee Surgery

Overseen By Julie Desroches, Ph. D

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Centre hospitalier de l'Université de Montréal (CHUM)

Must not be taking: Opioids

Disqualifiers: Pregnancy, Under 50 kg, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Approved in 1 Jurisdiction This treatment is already approved in other countries

Compensation: Varies

Number of Visits: 1

Duration: 1 day

122 Participants Needed

Trial Summary

Will I have to stop taking my current medications?

The trial protocol does not specify whether you need to stop taking your current medications. However, if you are taking more than 60 mg of morphine daily for chronic pain, you would not be eligible to participate.

What data supports the effectiveness of the treatment Femoral Triangle Block (FTB) and related techniques for postoperative pain from knee surgery?

Research shows that the Femoral Triangle Block (FTB) can provide effective pain relief after knee surgery while preserving muscle strength better than other techniques like the femoral nerve block. Combining FTB with other nerve blocks, such as the anterior femoral cutaneous nerve block, can further reduce pain during movement in the early postoperative period. ^{1 2 3 4 5}

Is the Femoral Triangle Block (FTB) safe for use in humans?

The Femoral Triangle Block (FTB) is generally considered safe for use in humans, as it is designed to provide pain relief while minimizing muscle weakness compared to other nerve block techniques. However, like any medical procedure, it may have some risks, such as temporary muscle weakness, which should be discussed with a healthcare provider. ^{1 2 3 4 6}

How is the femoral triangle block treatment different from other treatments for knee surgery pain?

The femoral triangle block (FTB) is unique because it provides pain relief after knee surgery while preserving muscle strength, unlike the femoral nerve block which can cause significant quadriceps weakness. FTB is administered using ultrasound guidance, which helps target the nerves more precisely, reducing the risk of muscle weakness. ^{1 2 3 7 8}

What is the purpose of this trial?

Total knee replacement surgery can be associated with a significant postoperative pain burden and an inability to mobilize adequately, which can lead to the failure of the ambulatory course. Indeed, early mobilization is beneficial in this context in order to prevent complications related to immobility. The optimization of postoperative analgesia is therefore a key issue for the success of this intervention in an outpatient setting or during a short-term hospitalization since an adequate pain relief facilitate the earlier mobilization of the operated joint. Modern postoperative analgesia protocols recommend a multimodal approach, including the use of acetaminophen, anti-inflammatories, opioids and others as well as the use of nerve blocks. Some nerve blocks used for total knee replacement surgery, such as the femoral nerve block, do not preserve the motor skills of the operated limb, which may alter the clinical trajectory due to delayed mobilization due to weakening of the quadriceps, one of the extensor muscles of the knee. Currently, one of the blocks used to spare the motor functions is the block of the femoral triangle. Unfortunately, this block of the femoral triangle does not fully cover the skin component of the surgical incision used for a total knee arthroplasty. A solution to obtain a better quality of pain relief at the level of the cutaneous incision would be to add a block of the para-sartorial compartment, which makes it possible to cover the nerve territories not covered by the femoral triangle block. The hypothesis of this study is that the addition of the para-sartorial compartments (PACS) block, which aims to block the intermediate cutaneous femoral nerve, will improve the postoperative analgesia after total knee replacement surgery, compared to the classical isolated approach of the femoral triangle block (FTB).

Research Team

Maxim Roy, MD, FRCPC

Principal Investigator

Centre hospitalier de l'Université de Montréal (CHUM)

Eligibility Criteria

This trial is for adults over 18 needing a primary total knee replacement, with an 'American Society of Anesthesiologists' classification of 1 to 3. It's not for those who can't consent or communicate with the team, don't understand instructions, are pregnant, weigh under 50 kg, have contraindications to nerve blocks or take daily pain meds equivalent to more than 60 mg of morphine.

Inclusion Criteria

Your health condition falls within the categories 1 to 3 according to the American Society of Anesthesiologists classification.

Exclusion Criteria

I take more than 60 mg of morphine daily for chronic pain.

I weigh less than 50 kg.

I cannot have a peripheral nerve block due to health reasons.

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive nerve blocks including the femoral triangle block and potentially additional blocks for postoperative analgesia after knee replacement surgery

1 day

1 visit (in-person)

Immediate Postoperative Monitoring

Participants are monitored for pain levels, complications, and recovery quality within the first 24 hours after surgery

24 hours

Continuous monitoring

Follow-up

Participants are monitored for pain intensity, quality of recovery, and patient satisfaction up to 7 days after surgery

7 days

Treatment Details

Interventions

• Femoral Triangle Block (FTB)
• Infiltration between Popliteal Artery and Capsule of the Knee Block (IPACK)
• Para-Sartorial Compartments (PACS) Block

Trial Overview The study tests if adding a para-sartorial compartments (PACS) block to the femoral triangle block (FTB) improves pain relief after knee replacement surgery. The PACS aims at blocking additional nerves that aren't covered by FTB alone and could enhance postoperative analgesia allowing earlier mobilization.

Participant Groups

Group I: Para-Sartorial Compartment (PACS) Block + Femoral Triangle Block (FTB) + IPACK block Experimental Treatment 3 Interventions

In addition to the injection performed in the femoral triangle, two injections of 5 mL of 0.5% ropivacaine + epi 1:400 000 will be performed below the sartorius muscle (subsartorial compartment) and above the sartorius muscle (suprasartorial compartment). For all patients, an infiltration between popliteal artery and capsule of the knee block (IPACK) will be performed concomitantly, in order to block the sensory branches of the innervation posterior to the knee with 15 ml of ropivacaine 0.3% + epi 1:400 000.

Group II: Femoral Triangle Block (FTB) + IPACK block Active Control 2 Interventions

This block is currently the most used in practice and is considered a standard of care. It consists of a single injection of 15 ml of 0.5% ropivacaine + epi 1:400 000 under the sartorius muscle, lateral to the femoral artery, at the level of the apex of the femoral triangle For all patients, an infiltration between popliteal artery and capsule of the knee block (IPACK) will be performed concomitantly, in order to block the sensory branches of the innervation posterior to the knee with 15 ml of ropivacaine 0.3% + epi 1:400 000.

Who Is Running the Clinical Trial?

Centre hospitalier de l'Université de Montréal (CHUM)

Lead Sponsor

Trials

389

Recruited

143,000+

Findings from Research

In a study of 80 patients undergoing total knee arthroplasty, combining an anterior femoral cutaneous nerve block (AFCNB) with a femoral triangle block (FTB) significantly reduced pain during movement 12 hours post-surgery compared to FTB alone, with a mean difference in pain scores of -2.02.

The AFCNB + FTB group also experienced lower incidence of surgical site pain and reduced morphine consumption within 48 hours postoperatively, while showing improved quadriceps muscle strength immediately after surgery.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The analgesic efficacy of anterior femoral cutaneous nerve block in combination with femoral triangle block in total knee arthroplasty: a randomized controlled trial. Kampitak, W., Tanavalee, A., Tansatit, T., et al.[2022]

In a study of 44 patients undergoing total knee arthroplasty, the femoral triangle catheter (FTB-Cath) resulted in significantly better preservation of quadriceps strength compared to the femoral nerve block catheter (F-Cath) on postoperative day 2, with 77.3% of FTB-Cath patients scoring ≥4 on the Manual Muscle Test versus only 13.6% in the F-Cath group (p < 0.001).

Both techniques provided similar pain relief, indicating that the FTB-Cath is an effective alternative for regional analgesia that minimizes quadriceps weakness while maintaining effective pain management.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Femoral nerve inguinal approach versus proximal femoral triangle ap proach for continuous regional analgesia in active rehabilitation after total knee arthroplasty: A prospective, randomised study. Guilley, J., Besançon, I., Hivert, A., et al.[2022]

Femoral nerve block (FNB) resulted in significantly lower quadriceps strength at 6 hours postoperatively compared to femoral triangle block (FTB) and adductor canal block (ACB), but all groups showed no differences in strength at 24 and 48 hours, indicating that FNB may initially impair muscle strength without affecting long-term recovery.

FNB provided better pain control at 6, 24, and 48 hours post-surgery compared to FTB and ACB, while ACB required the highest cumulative opioid use, suggesting a trade-off between pain management and muscle strength preservation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Single-injection nerve blocks for total knee arthroplasty: femoral nerve block versus femoral triangle block versus adductor canal block-a randomized controlled double-blinded trial. de Arzuaga, CIS., Miguel, M., Biarnés, A., et al.[2023]

This meta-analysis of five randomized controlled trials involving 308 patients found no significant differences in pain control (measured by VAS scores) or opioid consumption between femoral nerve block (FNB) and fascia iliaca block (FIB) for postoperative pain management after total knee and hip arthroplasties.

Both FNB and FIB showed similar safety profiles, with no significant increase in complications such as nausea, vomiting, or pruritus, suggesting that either technique can be safely used for pain control in these surgeries.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Femoral nerve block versus fascia iliaca block for pain control in total knee and hip arthroplasty: A meta-analysis from randomized controlled trials. Wang, X., Sun, Y., Wang, L., et al.[2022]

In a study of 78 patients undergoing total knee arthroplasty, the combination of an obturator nerve block (ONB) and a femoral triangle block (FTB) significantly reduced opioid consumption to just 2 mg in the first 24 hours, compared to 20 mg for FTB alone and 17 mg for local infiltration analgesia (LIA).

Patients receiving the combined ONB and FTB also experienced less pain, nausea, and vomiting, indicating improved postoperative comfort without negatively affecting their ability to ambulate.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The Analgesic Effect of Obturator Nerve Block Added to a Femoral Triangle Block After Total Knee Arthroplasty: A Randomized Controlled Trial. Runge, C., Børglum, J., Jensen, JM., et al.[2019]

In a study of 90 patients undergoing total knee arthroplasty, the combination of 0.1% ropivacaine with dexmedetomidine resulted in better preservation of quadriceps muscle strength compared to higher concentrations of ropivacaine, indicating a safer option for pain management post-surgery.

Patients receiving the dexmedetomidine and lower concentration ropivacaine also demonstrated improved walking ability, as measured by the Timed Up and Go test, without compromising pain control compared to higher doses of ropivacaine.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The Effect Of Dexmedetomidine As Adjuvant To Ropivacaine 0.1% For Femoral Nerve Block On Strength Of Quadriceps Muscle In Patients Undergoing Total Knee Arthroplasty: A Double-Blinded Randomized Controlled Trial. Yang, X., Kang, W., Xiong, W., et al.[2022]

In a study of 100 patients undergoing total knee and hip replacement, the fascia iliaca compartment block (FIB) provided better pain control after the first six hours post-surgery compared to the femoral nerve block, as indicated by lower Visual Analogue Scale (VAS) scores at 24 hours.

While the femoral nerve block was more effective in reducing pain and analgesic consumption in the first 30 minutes, the FIB resulted in a higher quality of recovery, as measured by the QoR-40 questionnaire, 24 hours after surgery.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Comparison of the efficacy of femoral nerve block and fascia iliaca compartment block in patients with total knee replacement. Kanadli, H., Dogru, S., Karaman, T., et al.[2019]

Femoral nerve block significantly improves postoperative pain management after outpatient anterior cruciate ligament repair, with patients receiving a sham block reporting higher pain scores and needing more intravenous analgesia.

Both 0.25% and 0.5% bupivacaine provided effective analgesia lasting approximately 23.2 and 25.7 hours, respectively, demonstrating that femoral nerve blocks can enhance recovery in the immediate postoperative period.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Femoral nerve block with 0.25% or 0.5% bupivacaine improves postoperative analgesia following outpatient arthroscopic anterior cruciate ligament repair. Mulroy, MF., Larkin, KL., Batra, MS., et al.[2022]

References

1. Korea (South) pubmed.ncbi.nlm.nih.gov

The analgesic efficacy of anterior femoral cutaneous nerve block in combination with femoral triangle block in total knee arthroplasty: a randomized controlled trial. [2022]

2. France pubmed.ncbi.nlm.nih.gov

Femoral nerve inguinal approach versus proximal femoral triangle ap proach for continuous regional analgesia in active rehabilitation after total knee arthroplasty: A prospective, randomised study. [2022]

3. Germany pubmed.ncbi.nlm.nih.gov

Single-injection nerve blocks for total knee arthroplasty: femoral nerve block versus femoral triangle block versus adductor canal block-a randomized controlled double-blinded trial. [2023]

4. United States pubmed.ncbi.nlm.nih.gov

Femoral nerve block versus fascia iliaca block for pain control in total knee and hip arthroplasty: A meta-analysis from randomized controlled trials. [2022]

5. England pubmed.ncbi.nlm.nih.gov

The Analgesic Effect of Obturator Nerve Block Added to a Femoral Triangle Block After Total Knee Arthroplasty: A Randomized Controlled Trial. [2019]

6. New Zealand pubmed.ncbi.nlm.nih.gov

The Effect Of Dexmedetomidine As Adjuvant To Ropivacaine 0.1% For Femoral Nerve Block On Strength Of Quadriceps Muscle In Patients Undergoing Total Knee Arthroplasty: A Double-Blinded Randomized Controlled Trial. [2022]

7. Italy pubmed.ncbi.nlm.nih.gov

Comparison of the efficacy of femoral nerve block and fascia iliaca compartment block in patients with total knee replacement. [2019]

8. England pubmed.ncbi.nlm.nih.gov

Femoral nerve block with 0.25% or 0.5% bupivacaine improves postoperative analgesia following outpatient arthroscopic anterior cruciate ligament repair. [2022]