Lateral humerus epicondylitis- a clinical, muscle morpological, muscle metabolical and functional evaluation of a new model for treatment.

INTERVENTION: Trade Name: Dysport Product Name: botulinum toxin Pharmaceutical Form: Powder for solution for injection Pharmaceutical form of the placebo: Solution for injection Route of administration of the placebo: Intramuscular use CONDITION: Chronic lateral humerus epiconcylitis ; MedDRA version: 16.0 Level: LLT Classification code 10024032 Term: Lateral epicondylitis System Organ Class: 100000004863 Therapeutic area: Diseases [C] ‐ Musculoskeletal Diseases [C05] PRIMARY OUTCOME: Main Objective: To examine whether the transient paralysis of the extensor carpi radialis muscle by botulinum toxin injecton can increase circulation and reduce metabolites such as lactic acid in order to reduce pain without the need for surgery. Primary end point(s): Efficiacy of treatment, measured as recuction of pain according to VAS. Secondary Objective: Whether botox treatment results in changes in muscle morpholocy in the extensor carpi radialis muscle and whether those changes are permanent. Timepoint(s) of evaluation of this end point: 3 and 12 months post treatment SECONDARY OUTCOME: Secondary end point(s): Efficiacy of treatment, measured as: ; a: Function according to DASH, AROM etc. ; b: Blood flow as measured by Laser Doppler ; c: Accumulation of metabolites (e.g. lactic acid), measured by microdialysis ; d: Properties of biopsies Timepoint(s) of evaluation of this end point: a/b/c: 3 and 12 months post treatment ; d: 6 hours, 6 weeks and 6 months post treatment INCLUSION CRITERIA: Chronic unilateral epicondylitis, verified by hand surgeon No or inadequate response to conservative treatment No treatment the past 6 months 30‐55 y.o. Capable of giving informed consent Are the trial subjects under 18? no Number of subjects for this age range: F.1.2 Adults (18‐64 years) yes F.1.2.1 Number of subjects for this age range 50 F.1.3 Elderly (>=65 years) no F.1.3.1 Number of subjects for this age range