RecruitingOBSERVATIONAL

Evaluation of Local Anesthetic Diffusion to the Sciatic Nerve During Adductor Canal Block

This research is investigating a common pain-relief injection called an adductor canal block, often used for knee surgery. While it's known to be very effective, doctors believe its pain-blocking power might come from more than just blocking the main nerve it's designed for. They think the medicine might also spread to two other important nerves in the leg, the fibular and tibial nerves, through a pathway called the adductor hiatus. The main goal of this study is to find out exactly how often this spread happens. By understanding this, doctors can get a clearer picture of why this injection works so well and potentially improve pain management strategies for people having knee operations.

At a glance

Status

Recruiting

Sponsor

Assistance Publique - Hôpitaux de Paris

Enrolment target

Start

10 Dec 2025

Estimated completion

01 Dec 2027

Sciatic Nerve Adductor Canal Syndrome

What is this study about?

When you have major knee surgery, managing pain afterward is really important for your recovery. One common way doctors help with this is by giving an injection called an adductor canal block. It's a type of local anaesthetic, which means it numbs a specific area to help with pain. Doctors have found this block to be very good at relieving pain after knee operations, and some even recommend it as the first choice for pain relief during total knee replacement surgery. It's even been shown to work just as well as other common pain blocks.

Now, this block is mainly aimed at numbing a nerve called the saphenous nerve. It might also affect a couple of other smaller nerves. However, doctors believe that simply numbing these nerves doesn't completely explain why the adductor canal block is so effective at managing pain throughout the knee area. They suspect that the numbing medicine might spread further than initially thought.

Previous studies have hinted that the anaesthetic can travel along a pathway in your leg called the adductor hiatus and reach two other important nerves: the tibial nerve and the fibular nerve. These nerves are responsible for feeling and movement in different parts of your lower leg and foot. While it's known that this spread can happen, nobody has actually measured how often it does. This study aims to do just that – to find out how frequently the adductor canal block truly spreads to these other nerves. By understanding this, medical teams can better understand how this pain block works and potentially improve how they use it to help patients recover comfortably after knee surgery.

Key takeaways

This study investigates how effective a common pain block for knee surgery is.
It aims to see if the numbing medicine spreads to other important leg nerves.
Participation involves simple checks of feeling and movement in your leg after the block.
You would already be receiving the adductor canal block as part of your planned care.
The findings could lead to better pain management for future knee surgery patients.

Who may be eligible?

To be considered for this study, you need to be at least 18 years old and scheduled for knee surgery at the hospital where the study is taking place. You'll also be having a general anaesthetic for your surgery and receiving an adductor canal block for pain relief.

However, there are certain reasons why you wouldn't be able to join. For example, if you have any conditions that affect your thinking or understanding, or if you have nerve problems in your leg, you wouldn't be eligible. Also, if you're pregnant or breastfeeding, or if you're already receiving other specific pain-relief treatments for your knee surgery (like an IPACK block or direct surgical painkillers), you wouldn't be able to participate.

Finally, if you're unable to give your consent, in prison, don't have medical insurance, or simply prefer not to take part, that's perfectly fine and you won't be included in the study.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

Are you 18 years old or older?
Are you scheduled for knee surgery at this hospital?
Will you be having a general anaesthetic for your surgery?
Will you be receiving an adductor canal block for pain relief?
Are you able to understand and agree to take part?

Answer every question to see your result.

What does participation involve?

If you decide to take part, the main thing that will happen is a bit of extra testing related to the adductor canal block you would already be getting for your surgery. Before your surgery, after your adductor canal block has been given, the medical team will assess the feeling and movement in your lower leg and foot. They will be checking to see if the numbing medication has reached the fibular and tibial nerves. This is a "clinical sensorimotor testing," which simply means they'll gently check how well you can feel and move your leg in specific ways. This part of the study happens just once, around the time of your surgery and block, and there are no extra follow-up visits specifically for the study after that.

Potential risks and benefits

Taking part in this study could help doctors better understand how effective pain relief injections work, which may improve future pain management for patients having knee surgery. The study involves no extra procedures, as the adductor canal block is a standard part of your care. The potential risks are those already associated with receiving an adductor canal block, which your doctor will explain to you. There are no additional risks from the study's assessments themselves. Remember, your participation is completely voluntary, and you can withdraw at any time without it affecting your medical care.

Locations (1)

Department of Anesthésia, CHU Raymond Poincaré - APHP
Verified postcode
Boulogne-Billancourt, France· Recruiting

Common questions

What is an adductor canal block?

It's a type of injection that numbs a specific area in your leg to help reduce pain, especially after knee surgery.

Why are doctors studying this injection?

They want to understand exactly how the pain-numbing medicine spreads to different nerves in the leg to explain why it's so good at pain relief.

Will I get extra medicine or different treatment?

No, you'll receive the standard adductor canal block you're already scheduled for. The study just adds some checks on how it works.

What kind of tests will be done if I participate?

After your injection, doctors will gently test the feeling and movement in your lower leg and foot to see if the numbing has spread.

Does participating mean more appointments?

No, the assessments for the study will happen around the time of your surgery and won't require extra visits afterwards.

How to find out more

Romuald Henry, MD

romuald.henry@aphp.fr + 33 06 72 83 17 51 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.