The aim of the study is to assess the effectiveness of botulinum toxin in persistent shoulder pain due to degenerative rotator cuff disease.

Epidemiology:

degenerative rotator cuff disease ranks first in shoulder disorders and is the main cause of chronic shoulder pain in general practice and in rheumatology clinics. It can be responsible for persistent shoulder pain, functional limitation and greatly contributes to occupational disability.

The pathogenesis of rotator cuff disease:

involves tendon impingement and intrinsic tendinopathic abnormality (supra-spinatus, infra-spinatus, teres minor and sub-scapularis muscles). They include apoptosis of the tenocytes that is induced by mechanical constraints and by local hypoxia. The consequences are secondary inflammation and matrix alteration.

Current therapeutic approach:

The first-line recommended treatment for degenerative rotator cuff disease is conservative and includes level 1 and 2 oral analgesics; a short sequence of nonsteroidal anti-inflammatory drugs, if necessary; local injections of corticosteroids; and physiotherapy (low level of evidence). Surgery is a conditional later option.

Study hypothesis:

Reducing mechanical constraints on the supra-spinatus tendon by botulinum toxin may prevent load-induced apoptosis of the tenocytes and tear progression that is associated with clinical expression, and prevent local hypoxia. Furthermore, the muscle inactivity induced by botulinum toxin is not awaited to provide any clinically relevant functional alteration.

Aim of the study:

The primary objective of the study is to assess the effectiveness of botulinum toxin in persistent shoulder pain due to degenerative rotator cuff disease at one-month follow-up, using Shoulder Pain And Disability Index (SPADI) as outcome criterion.

The secondary objective is to assess the effectiveness of botulinum toxin in persistent shoulder pain due to degenerative rotator cuff disease, at three-month follow-up, using SPADI as outcome criterion and safety, the SPADI sub-scores pain and function at 3 months, global improvement perceived at 1 month and 3 months, drug consumption over the 3 months of follow-up, and treatment acceptability at 1 month and 3 months; as well as the tolerance at 1 week.

Inclusion Criteria:

• age > 40 years;
• pain duration > 1 month;
• pain intensity ≥ 40/100 on visual analog scale;
• SPADI ≥ 30/100;
• medication against pain stable at least 30 days before enrolment;
• pain with or without weakness during the Jobe manoeuver;
• ultrasonography within the 30 days, showing tendinopathy of the supra-spinatus, with or without tear;
• affiliation to health insurance Sécurité Sociale;
• ability to give consent, complete the weekly notebook (collection of drug treatments taken against pain);
• availability for the visits planned by the protocol;
• use of an effective method of contraception in women of childbearing potential, started at least 1 month before and lasting for at least 1 month after receiving study treatment.
• Negative urine test for women of childbearing age

Exclusion Criteria:

• reduced passive range of motion;
• antero-posterior instability;
• tendinous calcification;
• ultrasonography showing concomitant tear of the infra-spinatus or the subscapularis;
• corticosteroid injection within the previous 30 days;
• previous surgery of the shoulder;
• humeral fracture, inflammatory joint disease and neoplastic disorders;
• contraindication to XEOMIN® (allergy to XEOMIN® or any other botulinum toxin product);
• skin infection at the planned injection site;
• participation in another interventional research involving the human person (RIPH) during the 3 months of follow-up of the DEROTOX Research; participation in another RIPH will be possible beyond these 3 months;
• concomitant use of aminoglycosides, cyclosporine, aminoquinolines and spectinomycine;
• patients with a history of aspiration pneumonia and dysphagia;
• patients on anticoagulant therapy or on therapy that may have an anticoagulant effect;
• Patients with bleeding disorders;
• Patients with amyotrophic lateral sclerosis, myasthenia gravis or, Lambert-Eaton syndrome;
• Patients with other conditions causing peripheral neuromuscular dysfunction;
• In target muscles that show pronounced weakness or atrophy;
• Women of childbearing age who have not performed a urine pregnancy test and or who have a positive urine pregnancy test;
• in case of pregnancy, breastfeeding
• injection of botulinum toxin in the last 6 months
• vulnerable people (under legal protection, guardianship or curatorship)