Popliteal Sciatic Nerve Block: Intraneural or Extraneural?

Study Overview
=================
Brief Summary
-----------------
Aim of this study is to demonstrate the advantages of intraneural injection over extraneural injection in terms of onset and duration on peripheral block. In addition we will evaluate the frequency of possible adverse effects.

Official Title
-----------------
Blocco Del Nervo Sciatico al Poplite, Intraneurale o Extraneurale? Confronto Prospettico, Randomizzato in Cieco Tra la modalità di Iniezione di Anestetico Locale Per il Blocco Eco Guidato Del Nervo Sciatico al Poplite Nella Chirurgia Dell'Alluce Valgo

Conditions
-----------------
Hallux Valgus

Intervention / Treatment
-----------------
* Procedure: Intraneural injection
* Procedure: Extraneural injection
* Drug: Ropivacaine
* Device: PAJUNK SonoPlex 22G needle.


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: ASA I-II Exclusion Criteria: Neurological diseases Diabetes Allergies to used drugs Chronic pain in treatment Electrophysiological alterations at time zero analysis

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Intraneural injection<br>All patients in the arm will receive a single intraneural injection of 12 ml Ropivacaine 1% BBraun, Germany, in the sciatic nerve under echographic guidance. | Procedure: Intraneural injection<br>* BBraun Ropivacaine 1% 12ml injection divided in each sciatic components under echographic guidance with a PAJUNK SonoPlex 22G needle.<br>Drug: Ropivacaine<br> <br> Device: PAJUNK SonoPlex 22G needle.<br> <br> |
| Active Comparator: extraneural injection<br>All patients in the arm will receive a single extraneural injection of 12 ml Ropivacaine 1% BBraun, Germany, around the sciatic nerve under echographic guidance. | Procedure: Extraneural injection<br>* BBraun Ropivacaine 1% 12ml extraneural injection around sciatic nerve under echographic guidance with a PAJUNK SonoPlex 22G needle.<br>Drug: Ropivacaine<br> <br> Device: PAJUNK SonoPlex 22G needle.<br> <br> |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| onset time | Pinprick test evaluation on sciatic nerve territory: With a 22G needle the blinded operator will assess sensitiveness to puncture and then assign a score every 2 minutes for 30 minutes. A score of 0 will describe no sensation to puncture, on the other hand a score of 1 will be assigned if sensation to puncture is still present. Evaluation of motor blockade: Plantar and dorsal flexion of the foot will be evaluated for motor blockade of sciatic nerve. A score of 1 will be assigned if foot movement is conserved, 2 if is impaired and 3 when disappears. Onset time is described as the time at which pinprick score turns to 0 and motor blockade score turns to 3. | every 2 minutes for a maximum of 30 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| success rate in each group | Success rate is described as the percentage of subjects with an onset time within 30 minutes in a group among all subjects treated in that group | at 30 minutes | 
| Nerve injuries | Neurophysiological and clinic evaluation will be assessed either with clinical examination and electrophysiological tests by a neurophysiologist eventually evidencing any movement impairment or dysesthesia in the sciatic territory. | 1, 5 weeks and at 6 months after surgery |