Electric muscle stimulation for treatment of functional shoulder instability

ISRCTN ISRCTN10085480
DOI https://doi.org/10.1186/ISRCTN10085480
Submission date
25/03/2019
Registration date
05/04/2019
Last edited
03/05/2024
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Musculoskeletal Diseases
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data

Plain English Summary

Background and study aims
Functional posterior shoulder instability (FPSI) is a force imbalance of stabilizing shoulder muscles which mainly affects teenagers and young adults with severe effects on shoulder function. Patients with FPSI suffer from repetitive posterior displacements every time the shoulder passes a particular phase of movement in the mid-range of motion. Severely restricted shoulder function and symptoms such as pain, loss of range of motion due to weakness or blockage that inhibits any further movement, as well as a strong feeling of instability, are reported by the affected patients. Current therapy includes conservative as well as surgical stabilization attempts. In daily clinical practice, however, standard physiotherapy is often ineffective and after years of unsuccessful conservative treatment, patients affected with FPSI finally undergo a surgical stabilization attempt with results that are often worse than before. In a study with 5 participating centres, a promising therapy concept based on electric muscle stimulation shall be compared to the current standard care physiotherapy. If the results of the new treatment approach show better results than the existing standard physiotherapy, a much-needed step forward in the treatment of patients with FPSI will be achieved and likely lead to a complete change in the existing therapy for this challenging pathology. For the patients themselves, this new treatment concept possibly could represent a true „game-changer“ that might free them of the burden of FPSI.

Who can participate?
Participants over the age of 14 with FPSI will be included in this study irrespective of gender or duration of symptoms. Exclusion criteria focus on structural pathologies (static posterior migration, connective tissue diseases, degenerative joint diseases, structural defects) and other pathologies (multidirectional instability, neurological disorder or nerve injuries, existing pain syndrome, medical contraindication to EMS treatment) hindering, impeding, or prohibiting to complete the control or experimental treatment. Additionally, participants with previous participation in a pathology-targeted standardized EMS or physiotherapy protocol are excluded in order to avoid potential unwillingness to participate in or preformed mindset towards an intervention that they previously tried already without success.

What does the study involve?
The study will compare two treatment groups. The experimental intervention consists of an EMS-based training protocol to stimulate specific muscle groups of the shoulder. The training involves a combination of certain exercises with increasing difficulty and intensity. The control intervention includes a pathology-targeted standardized physiotherapy protocol which has been developed and agreed on by international renowned shoulder experts. Both experimental and control treatment will include 18 one-hour trainings evenly distributed over a time period of 6 weeks and will be performed by the same physiotherapist at each participating centre based on standardized protocols. In the case of subjectively unsatisfying results, an optional switch (cross-over) into the other treatment group is allowed to make both potentially superior therapies available to all participants within a reasonable time (3 months after the beginning/6 weeks after the end of the intervention).

What are the possible benefits and risks of participating?
Each participant benefits by receiving an intensive, targeted and potentially equal physiotherapeutic treatment concept. The training concepts aim to increase endurance and coordination including functional training as well as strengthen specific stabilizing shoulder muscles. In addition, as part of clinical routine, each participant will receive a clinical evaluation and individualized consultation on the likelihood of reoccurring shoulder displacements. No adverse events or complications of the experimental EMS-based therapy have been observed in a pilot study.

Where is the study run from?
This study will be available in centres across Germany and Switzerland and supervised by the Charité- Universitaetsmedizin Berlin as lead centre. Further centres include the ATOS Clinic, Munich, Germany; the Annastift Hospital, Hannover, Germany; the St. Vincentius Kliniken, Karlsruhe, Germany; Schoen Clinic Düsseldorf and University Clinic Düsseldorf, Germany; and the Schulthess Clinic, Zurich, Switzerland.

When is the study starting and how long is it expected to run for?
June 2019 to June 2022

Who is funding the study?
This project is currently initiated and funded by the investigators

Who is the main contact?
PD Dr. med. univ. Philipp Moroder
philipp.moroder@charite.de

Contact information

Dr Philipp Moroder
Scientific

Department of Shoulder and Elbow Surgery
Center for Musculoskeletal Surgery- Campus Virchow
Charitè Universitaetsmedizin
Augustenburgerplatz 1
Berlin
13353
Germany

Phone +4930450652175
Email philipp.moroder@charite.de

Study information

Study designMulti-centric randomized controlled therapeutic trial active control no masking optional cross-over design
Primary study designInterventional
Secondary study designRandomised cross over trial
Study setting(s)Hospital
Study typeTreatment
Participant information sheet Not available in web format, please use contact details to request a participant information sheet
Scientific titleElectric muscle stimulation for treatment of non-controllable positional functional posterior shoulder instability
Study acronymEMS for FPSI
Study hypothesisElectrical muscle stimulation (EMS) based therapy has the same clinical effect as conventional state-of-the art physiotherapy treatment for FPSI.
Ethics approval(s)Approved 30/08/2018, Ethics Committee of Charité – Universitaetsmedizin Berlin (Charitéplatz 1, Virchowweg 10, 10117 Berlin; +49 (0)30 450 517 222; ethikkommission@charite.de), ref: EA2/077/18
ConditionNon-controllable positional functional posterior shoulder instability (FPSI).
InterventionIn a multicentric prospective randomized controlled trial, we would like to objectively assess a promising new EMS-based treatment concept which was evaluated at our institution in a prospective pilot trial involving 24 cases with previously unsuccessful conventional physiotherapy treatment of FPSI. Pathology-targeted physiotherapy is the current standard treatment of FPSI and will serve as the control intervention in the proposed trial. All involved centers as well as independent experts have specified and agreed on a standardized exercise protocol for the control intervention during a Delphi survey. The control intervention will have the same duration, intervals, and instructing physiotherapist (at each center) as the experimental intervention. An optional bi-directional cross-over into the other intervention group (experimental or control) is possible after follow-up examination at the time-point T2 (3 months after the beginning/6 weeks after the end of the intervention) in the case of subjectively unsatisfying results despite completion of the originally assigned intervention to offer both possibly superior interventions to all participants.

Experimental intervention: electrical muscle stimulation based therapy protocol
Control intervention: conventional state-of-the art physiotherapy protocol
Follow-up per patient: 0 weeks (T0), 6 weeks (T1), 3 months (T2), 6 months (T3), 12 months (T4)
Duration of intervention per patient: 6 weeks

The strict inclusion and exclusion criteria create a homogeneous group of study participants. After a patient has decided to enter the study and provided written informed consent, he/she will be randomized in one of the two treatment groups (allocation ratio 1:1). A randomization sequence will be generated electronically using Stata (StataCorp LP, Texas USA) separately for each participating center and loaded within an online study database in REDCap17 (Research Electronic Data Capture) for automatic concealed allocation. Block-randomization with blocks of 2 and 4 will be used to minimize the risk of unequal group sizes. The randomization process allows to divide the study participants into two cohorts of comparable characteristics. We will compare these cohorts with regards to potential confounding factors before the outcome analyses and adjust statistically for any observed imbalance as appropriate.

Since the main outcome measurement is a subjective score, blinding of the examiner is not necessary. Blinding of the patients themselves is not possible due to the nature of experimental and control intervention. This circumstance can potentially introduce a confirmation bias from the patients’ side. However, according to the trial design, all patients with previous participation in a pathology-targeted standardized EMS or physiotherapy protocol are excluded which reduces the risk for a pre-conditioned mindset in patients.
Intervention typeProcedure/Surgery
Primary outcome measureWestern Ontario Shoulder Instability Index (WOSI) at T2
Secondary outcome measures1. WOSI at T1, T3, and T4.
At 0 weeks (T0), 6 weeks (T1), 3 months (T2), 6 months (T3), 12 months (T4):
2. Subjective shoulder value
3. Impairment of daily activities
4. Sports impairment
5. Pain level
6. Range of motion
7. Strength
8. Satisfaction with treatment

Assessment of safety: Based on the complication-free pilot trial, no adverse events are pre-specified but continuous recording of unexpected adverse events will be executed in both treatment arms.
Overall study start date01/11/2018
Overall study end date01/06/2022

Eligibility

Participant type(s)Patient
Age groupMixed
Lower age limit13 Years
SexBoth
Target number of participantsTo be assessed for eligibility: n = approximately 87 (expected exclusion rate of approximately 25%); To be assigned to the trial: n = 65 (accounting for an expected drop-out rate of approximately 20%); To be analysed: n = 52 (calculated sample size for a power of 80%, alpha error probability of 5%, and an estimated effect size of 0.8 at 12 months)
Total final enrolment59
Participant inclusion criteria1. Non-controllable positional functional posterior shoulder instability (FPSI)
2. Aged 13 years or over
Participant exclusion criteria1. Multidirectional instability
2. Static posterior instability/migration
3. Connective tissue disease
4. Degenerative joint disease
5. Structural defects visible on pre-treatment MRI
6. Neurological disorder or nerve injury
7. Existing pain syndrome (defined by pain at rest or during motion, which is not caused by dislocation but impedes physiotherapeutic training and/or EMS)
8. Non-tolerance of EMS treatment (e.g. cardiac pacemaker)
9. Previous participation in a pathology-specific standardized EMS or physiotherapy protocol

Added 21/02/2020:
5. Structural defects visible on pre-treatment MRI:
5.1. Any acquired glenoid bone defect
5.2. Glenoid dysplasia with more than 10° of retroversion (of cartilagineous surface) according to Imhoff et al.
5.3. Convex cartilagineous glenoid articular surface
5.4. Static posterior glenohumeral decentering >55% according to Walch et al.
5.5. Degenerative changes (any visible cartilage damage or OA)
Recruitment start date01/06/2019
Recruitment end date01/01/2022

Locations

Countries of recruitment

  • Germany
  • Switzerland

Study participating centres

Charité University Hospital
Centrum für Muskuloskeletale Chirurgie
Augustenburger Platz 1
Berlin
13353
Germany
Annastift Hospital
Anna-von-Borries-Straße 1-7
Hanover
30625
Germany
ATOS Clinic
Effnerstraße 38
Munich
81925
Germany
St. Vincentius Clinic
Südendstr. 32
Karlsruhe
76135
Germany
Schulthess Clinic
Lengghalde 2
Zurich
8008
Switzerland
Schoen Clinic Düsseldorf
Am Heerdter Krankenhaus 2
Düsseldorf
40549
Germany
University Clinic Düsseldorf
Moorenstraße 5
Düsseldorf
40225
Germany

Sponsor information

Charité - Universitaetsmedizin Berlin
University/education

Department of Shoulder and Elbow Surgery
Center for Musculoskeletal Surgery
Campus Virchow Klinikum
Augustenburger Platz 1
Berlin
13353
Germany

Phone +49 30 450 - 50
Email victor.danzinger@charite.de
ROR logo "ROR" https://ror.org/001w7jn25

Funders

Funder type

Research organisation

Deutsche Forschungsgemeinschaft
Government organisation / National government
Alternative name(s)
German Research Association, German Research Foundation, DFG
Location
Germany

Results and Publications

Intention to publish date01/10/2022
Individual participant data (IPD) Intention to shareYes
IPD sharing plan summaryAvailable on request
Publication and dissemination planThe results of the study are presented in a manuscript in accordance with the CONSORT guidelines and published in a scientific journal. To ensure general availability, the publication is made freely accessible. Moreover, the results will be presented at national and international conferences.
IPD sharing planThe datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Protocol file version v1.0 30/11/2019 02/12/2019 No No
Protocol file version v2.0 18/02/2020 18/02/2020 No No
Protocol file version v3.0 25/03/2020 25/03/2020 No No
Protocol file version v4.0 08/04/2020 04/06/2020 No No
Results article 01/01/2024 03/05/2024 Yes No

Additional files

ISRCTN10085480_Protocol_v1.0_30Nov2019.pdf
Uploaded 02/12/2019
ISRCTN10085480_Protocol_v2.0_18Feb2020.pdf
Uploaded 18/02/2020
ISRCTN10085480_PROTOCOL_v3.0_25March2020.pdf
Uploaded 25/03/2020
ISRCTN10085480_Protocol_v4.0_08Apr2020.pdf
uploaded 04/06/2020

Editorial Notes

03/05/2024: Publication reference added.
16/05/2022: The following changes have been made:
1. One of the public contacts has been removed and the plain English summary has been updated to reflect this change.
2. The total final enrolment number has been added.
11/01/2021: The following changes were made to the trial record:
1. The recruitment end date was changed from 01/01/2021 to 01/01/2022.
2. The overall trial end date was changed from 01/06/2021 to 01/06/2022.
3. The intention to publish date was changed from 01/10/2021 to 01/10/2022.
08/07/2020: The recruitment end date was changed from 01/06/2020 to 01/01/2021.
04/06/2020: The following changes were made to the trial record:
1. Recruitment resumed on 03/06/2020.
2. Uploaded protocol version 4.0, 08 April 2020, (not peer reviewed) as an additional file.
16/04/2020: Due to current public health guidance, recruitment for this study has been paused.
25/03/2020: Uploaded protocol version 3.0, 25 March 2020 (not peer reviewed).
21/02/2020: The exclusion criteria were updated and the trial participating centres were updated to add Schoen Clinic Düsseldorf and University Clinic Düsseldorf.
18/02/2020: Uploaded protocol version 2.0, 18 February 2020 (not peer reviewed).
02/12/2019: Uploaded protocol version 1.0, 30 November 2019 (not peer reviewed).
03/04/2019: Trial’s existence confirmed by IRB