Ultrasound Guided Single Shot Block of Posterior Tibial Nerve for Postoperative Pain Relief After Hallux Valgus Surgery

Study Overview
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Brief Summary
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Hallux surgery is known to be extremely painful. Standard pain therapy is treatment with NSAID and opioid painkillers. Patients are frequently not-satisfied with this. Some institutions use a nerve block (single shot or catheter technic) of the ischiadic nerve. But this procedure is invasive, has a potential risk of nerve lesion, and is not accepted by all surgeons. A single shot nerve block of the posterior tibial nerve is less invasive and could be superior compared to standard pain treatment. A great variability of nerve supply of the foot is well described. There are some hints that the posterior tibial nerve supplies the first metatarsal bone and the first metatarsal joint. A nerve block could reduce postoperative pain in hallux surgery. To assess the effectiveness of this investigated measure, the requested morphine dose of a PCA pump will be used to verify the effectiveness of the tibial nerve block.

Detailed Description
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The overall purpose is to evaluate the effectiveness of tibial nerve block for postoperative pain relief after hallux surgery. The primary objective is to assess the morphine requirement in the first 24 hours after surgery. Secondary objectives are maximum pain scores and sleeping quality in the postoperative period. Patient's satisfaction with the pain therapy and approximately nerve block duration will be asked in the final interview. Primary study endpoint is a 50% reduction of morphine requirement with a 60% standard deviation within 24 hours after surgery. Power is 80%, the level of significance is set at 5% (p < 0,05). Secondary endpoints are sleeping quality and maximum pain scores (maximum VAS) measured by means of postoperative questionnaire.

Official Title
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Monocentric, Non-blinded, Prospective Randomized Parallel Group Phase IV Clinical Study to Evaluate the Efficacy of Ultrasound Guided Single Shot Block of Nervus Tibialis Posterior for Postoperative Pain Relief After Hallux Valgus Surgery.

Conditions
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Hallux Valgus

Intervention / Treatment
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* Drug: Ropivacaine 0,75%
* Procedure: posterior tibial nerve block
* Drug: morphine and droperidol


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age over 18 years Elective Hallux valgus surgery (Magerl operation technique) Exclusion Criteria: Patient refusal, pregnancy Regular medication with opioids Drug abuse Contraindication for regional anesthesia Known allergy against one of the study drugs Polyneuropathia, or any other neurodegenerative disorders

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: study group<br>single shot, posterior tibial nerve block with 5 ml of Ropivacaine 0,75% before surgery postoperative PCA pump with morphine and droperidol (DHBP®) for the next 24 hours. | Drug: Ropivacaine 0,75%<br>* Ropivacaine injection<br>* Other names: Naropin 0,75%;Procedure: posterior tibial nerve block<br>* ultrasound guided posterior tibal nerve block<br>Drug: morphine and droperidol<br>* i.v PCA<br>* Other names: DHBP;|
| Other: controll Group<br>After surgery: standard analgesic treatment by PCA (patient controlled analgesia) pumps with morphine and Droperidol (DHBP®) for the next 24 hours. | Drug: morphine and droperidol<br>* i.v PCA<br>* Other names: DHBP;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| morphine requirement | a 50% reduction of morphine requirement with a 60% standard deviation within 24 hours after surgery. Power is 80%, the level of significance is set at 5% (p < 0,05). | 24 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| sleeping quality | sleeping quality in the first postoperative night, questionaire | 24 hours |