Tendinopathy treatment poses a current challenge for sport medicine due to unique physiolog and biomechanics of tendons. The goal of this work was to compare the efficacy of the addition of the radial pressure wave therapy (RPWT) treatment to injection of autologous Adipose Derived Stem Cells (ADSCs) or Platelet Rich Plasma (PRP) in the therapeutic procedure for collagenase induced Achilles tendinopathy in sheep. 14 sheep (aged 5 and 6 years, Polish Mountain Sheep breed, weight 60-70 kg) were injected bacterial collagenase type 1A-S (Clostridium histolyticum, C-5894, Sigma Aldrich, Poznań, Poland) bilaterally to Achilles tendons. Subsequently, the animals were injected with PRP (7 sheep) or ADSCs (7 sheep) to previously induced tendinopathy foci. Left limbs of all the animals were additionally treated with RPWT focused above the tendinopathy origins. Treatment progress was controlled by ultrasound scans, and tendon samples were taken on the 126th day of the experiment. Tendon samples taken from the sheep treated with RPWT+ADSCs showed lower cellularity and the highest number of thick collage fibers. Samples taken from the sheep treated with RPWT+PRP showed an elevated rate of neovascularization. Addition of the RPWT to ADSCs injections in the treatment of induced Achilles tendinopathy in sheep resulted in good quality of the tissue regeneration. Dual therapy with RPWT+PRP injection can lead to neovascularization in the tendon tissue.

Novel tendinopathy treatment protocols should be assessed for safety. The goal of this work was to compare differences in selected systemic inflammatory marker concentrations after two treatment protocols for collagenase induced Achilles tendinopathy in sheep. 14 sheep (aged 5 and 6 years, Polish Mountain Sheep breed, weight 60-70kg) were injected with bacterial collagenase type 1A-S (Clostridium histolyticum, C-5894, Sigma Aldrich, Poznań, Poland) bilaterally to Achilles tendons. Subsequently, the animals were injected with Platelet Rich Plasma (7 sheep) or Adipose Derived Stem Cells (7 sheep) to induced tendinopathy foci. Left limbs of all sheep were additionally treated with Radial Pressure Wave Therapy (RPWT) focused above the tendinopathy origins. Treatment progress was controlled by ultrasound scans, and tendon samples were taken on the 126th day of the experiment. Serum Amyloid A (SAA) concentration showed mild elevation before the experiment (2 sheep from group I, 4 sheep from group II) and two days after the intratendinous growth factors injection ( 4 sheep from group I, 3 sheep from group II) combined with RPWT (mean 22,63 mg/L and 53, 6 mg/L respectively). Haptoglobine (Hp) concentration increased from 0 to 0,01 g/L in 2 animals from group I two days after injection. These values declined to 0 during the course of the treatment. Fibrinogen (Fb) concentrations were within reference levels throughout the research, although mild elevation was observed before the treatment course in 6 sheep from group I and 1 sheep from group II. In conclusion, addition of RPWT to growth factors injections in the treatment of yatrogenic Achilles tendinopathy in sheep did not induce systemic inflammatory response.