Evaluation of Three Types of Injection for the Treatment of Lateral Epicondylalgia

General inclusion criteria: * The patient must have given free and informed consent and signed the consent * The patient must be affiliated or beneficiary to a health insurance plan * The patient is available for 6 months of follow-up * Woman of childbearing age using contraception Inclusion criteria for the target population: the patient has a side epicondylalgia objectified by: * Clinical criteria: symptoms lasting for more than 6 weeks and less than 12 months. The list of symptoms to be present are: pain on palpation of the lateral epicondyle, pain in the lateral epicondyle during blocked contraction * Therapeutic: less than two injections of corticosteroids performed, and the last such injection was performed at least 3 months before inclusion General non-inclusion criteria: * The patient is participating in another study * The patient is exclusion period determined by a previous study * The patient is under judicial protection * The patient is under guardianship or curatorship * The patient refuses to sign the consent * Woman of childbearing age not using contraception * Impossible to correction inform the patient about the study Non-inclusion criteria for investigational and auxiliary medicinal products: * The patient has at least one of the contra-indications listed in the SPC for Xeomin and ALTIM: * Hypersensitivity to Botulinum neurotoxin type A or Cortivazol * Hypersensitivity to any of the excipients used in the composition of XEOMIN (Human albumin, sucrose) and / or ALTIM (Benzyl alcohol, carmellose sodium, sodium chloride, cetylpyridinium chloride, polysorbate 80) * Generalized disorders of muscle activity (eg myasthenia gravis, Lambert-Eaton syndrome). * Severe coagulation disorders, anticoagulation in progress (ticlopidine, clopidogrel, other antiplatelet or antithrombotic agents) * Presence of a local or general infection, suspected infection, infection at the proposed injection site. Non-inclusion criteria for the medical device used for the PRP samples (SmartPReP2 sampling system): * Clinical or laboratory evidence for sepsis * Taking aspirin or other drugs altering platelet function in the previous 3 days * Patient with the platelet dysfunction disorders Non-inclusion criteria for interfering diseases or conditions: * The patient is pregnant, parturient or she is breastfeeding * The patient has an allergy to botulinum toxin type A and / or glucocorticoids * The patient has medial epicondylalgia * The patient has a history of elbow surgery * The patient has any of the following conditions: immunodeficiency, rheumatic disease, hepatitis, diabetes, another disease of the ipsilateral limb, neurological disorder (radiculopathy, compression of the radial nerve), any myopathy (all etiologies) * The patient received treatment with corticosteroids in the last 3 months * The patient is being treated with long-term anti-platelet medication