Deltoid Muscle Contribution to Shoulder Function
|ClinicalTrials.gov Identifier: NCT03881462|
Recruitment Status : Completed
First Posted : March 19, 2019
Last Update Posted : January 14, 2020
There is only one study in the literature about the quantitative effect of M. deltoideus on the movement of the shoulder. Here, the author described a 35-80% loss of abduction power after selective blockade of the N. axillaris. Gerber, on the other hand, found a loss of abduction force of 73-86% after blockade of the suprascapular nerve. These results are partly contradictory, which is why the investigators think that further investigation is needed.
For many questions in the field of shoulder orthopedics, this knowledge would provide an important additional basis for therapeutical decision-making. For example, in the treatment of rotator cuff ruptures but also in the implantation of both inverse and anatomical shoulder prostheses. Also, statements about different outcome prognoses could be made more precisely.
Therefore, the investigators would like to perform muscle strength measurements of the deltoid muscle on 12 healthy volunteers on the dominant arm.
Abduction, flexion, external rotation and internal rotation Mm. Infraspinatus, Supraspinatus and Subscapularis are tested respectively.
The investigators plan to carry out the measurements three times before and after an-anaesthesiological nerve block of the axillary nerve thus inactivating the deltoid muscle (performed exclusively by an anesthesiologist specialized in regional anesthesia). The success of the nerve block is confirmed by needle electromyographies (EMG) by a neurologist specialized in electrophysiology. Using EMG neurogenic pathologies within the tested muscles are also ruled out.
In order to exclude relevant rotator cuff pathologies the investigators will perform shoulder radiography in three planes and sonography of the rotator cuff before conducting the experiment described above.
|Condition or disease||Intervention/treatment||Phase|
|Nerve Injury Nerve Palsy||Procedure: Axillary nerve block for artificial deltoid muscle palsy||Not Applicable|
|Study Type :||Interventional (Clinical Trial)|
|Actual Enrollment :||12 participants|
|Intervention Model:||Single Group Assignment|
|Masking:||None (Open Label)|
|Primary Purpose:||Basic Science|
|Official Title:||Deltoid Muscle Contribution to Shoulder Function - An Experimental Approach|
|Actual Study Start Date :||May 1, 2019|
|Actual Primary Completion Date :||July 30, 2019|
|Actual Study Completion Date :||September 30, 2019|
Experimental: Axillary nerve block
Axillary nerve block is performed in standardized manner and muscle force is measured before and after the block.
Procedure: Axillary nerve block for artificial deltoid muscle palsy
Axillary nerve block block (AXNB):
The ultrasound probe is placed transversally in the infraclavicular region with the arm in 90° abduction. The brachial plexus and its cords are identified l lateral to the brachial artery. The posterior cord is identified by ultrasound and is blocked - or, if the axillary nerve visible too - the axillary nerve is selectively blocked when it leaves the posterior cord and lies on the subscapular muscle accompanied by the posterior circumflex humeral artery. Using an in-plane technique, a short bevel connected to a nerve stimulator with the setting 0.5 mA current intensity, 0.1 ms impulse duration and 2 Hz impulse frequency for dual guidance, will be advanced until its tip is positioned near the nerve without eliciting motor contractions. After careful negative (for blood) aspiration local anesthetic will be applied until the targeted neuronal structure is surrounded by the injected fluid.
- Muscle strength of the rotator cuff [ Time Frame: 6 hours ]Strength of abduction, flexion, external rotation and internal rotation in Mm. infraspinatus, supraspinatus and subscapularis respectively measured in Newton before and after blockade of the N. axillaris.
- Geometric shoulder data [ Time Frame: 15 minutes ]Analysis of the geometric data of the X-ray images and correlation with the primary outcome.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03881462
|Balgrist University Hospital|
|Zürich, Switzerland, 8008|