Intra Articular Injection of Botulinum Toxin Versus Corticoids in Gonarthrosis

Analysis of Antalgic Efficacy of an Intra Articular Injection of Botulinum Toxin Versus Corticoids in Gonarthrosis by Perfusion MRI:a Superiority, Randomized, Controlled, Double Blind Study

We believe we can demonstrate a link between the analgesic action of intra-articular injection of botulinum toxin and synovial inflammation by Dynamic Contrast Enhancement (DCE) perfusion Magnetic Resonance Imaging (MRI).

Knee osteoarthritis is one of the most common causes of joint pain and functional disability in the general population.

Intra-articular infiltrations of corticoids are indicated for painful crisis especially if accompanied of effusion. However, this effect lasts only 2 weeks.

Given the lack of effective long-term medical-infiltrative treatment, we believe that botulinum toxin type A could be used by its direct action on mediators of neuro-gene inflammation at the joint level and its indirect medullary action by retrograde migration.

To date, 2 published randomized controlled trials and one unpublished Phase Ib clinical trial have shown that botulinum toxin injected intraarticularly improves pain and functionality in gonarthrosis.

Dynamic Contrast Enhancement (DCE) Magnetic Resonance Imaging (MRI) demonstrated the correlation between synovial inflammation and pain in gonarthrosis in a cohort of 454 subjects. It has also made it possible, via the monitoring of synovial inflammation, to demonstrate the efficacy of treatments in patients suffering from rheumatoid arthritis in the early phase, juvenile chronic arthritis or osteoarthritis.

DCE MRI perfusion therefore appears here as the technique of choice to follow the evolution of synovial inflammation after botulinum toxin injection in patients with symptomatic gonarthrosis.

Inclusion Criteria:

• Presenting gonarthrosis of degenerative origin, Kellgren/Lawrence Radiological Stage I to III, with a maturity of more than 18 months

• With pain intensity greater than or equal to 50/100 on an VAS

• In case of bilateral gonarthrosis, the VAS of the contralateral knee must be less than or equal to 30/100

• Presenting a failure of conventional per os treatments (non-steroidal anti-inflammatory drugs, analgesics)

• Affiliated with a social security scheme

• For women of childbearing age:

  • effective contraception for the duration of the study

Exclusion Criteria:

• Patient presenting at the time of the inclusion visit: an inflammatory attack, septic or inflammatory arthritis, a generalized infectious episode in progress
• Local or regional local skin lesion
• Need of an arthroplasty within the next 12 months
• Having received corticosteroids or other molecules in intra-articular infiltration in the last 6 months
• History of traumatic knee injury (bone injury in the past 24 months), bone, ligament or meniscal surgery in the past 24 months
• History of disabling peripheral nerve injury
• Severe bleeding disorders, anticoagulant treatment in progress or double antiplatelet aggregation
• BMI > 35 kg/m2
• Coxarthrosis with projected knee pain
• Pregnant or breastfeeding woman
• Patient under guardianship and protection of justice
• Allergy/contraindication to botulinum toxin type A, corticoids
• Usual contraindication to MRI
• Allergy to the contrast product