This is a clinical trial, unicentric, prospective, controlled, randomized, double blind during the experimental phase A.

In the experimental phase B, it is contemplated to administer the experimental treatment to the subjects included in the group treated with P-PRP in the event that the first treatment would be significantly more effective, both from a clinical and regenerative point of view

• Main objective

  1. Confirm the presence of patellar tendon gap regeneration after the peritendinous and intratendinous infusion of MSV and compare it with the P-PRP group, evaluated by ECO, NMR and UTC.
  2. To evaluate the clinical efficacy of infusion of MSC in refractory patellar tendinopathy compared with the P-PRP group through the subjective clinical evolution of the patient, the EVA and VISA-P questionnaires and the strength of the extensor muscle group measured by dynamometry.

• Secondary objective 1. To evaluate the feasibility and safety of the advanced therapy medication MSV and P-PRP when applied by percutaneous infusion into the body of the patellar tendinosis, verifying that each of the procedures established in the protocol is feasible and recording the possible adverse effects related with both treatments and adverse events arising during the period of the clinical trial, whether or not related to it

Inclusion Criteria:

1. Male sex with ages between 18 and 48 years.
2. Pain in the patellar tendon, located in the patellar insertion area, of more than 4 months of duration that does not show significant improvement after conservative treatments such as rest, analgesia, physiotherapy and / or infiltration.
3. Ultrasound image that confirms, both static and dynamic, the loss of the fibrillar structure of the proximal part of the patellar tendon, its thickening and a hypoechoic lesion compatible with gap ≥3mm.
4. MRI of the patellar tendon in T2 FAT SAT sequence (fat saturation) that shows a gap ≥3mm in longitudinal diameter in the proximal insertion.
5. Informed Consent in writing and signed by the patient.
6. The patient is able to understand the nature of the study.

Exclusion Criteria:

1. Patient under 18 years of age (or legally dependent) and over 48 years of age.

2. MRI with grade III-IV intra-articular pathology of all compartments of the knee and / or cruciate ligament injury

3. Local treatment with corticosteroids during the last year

4. Local treatment with PRP during the last 6 months.

5. Present infection (no local or systemic infectious signs should be evidenced).

6. Patients presenting positive serology in front of:

   HIV 1 and 2, Hepatitis B (HBsAg, HBcAc), Hepatitis C (Anti-HCV-Ab), Lúes.

7. Congenital or evolutive diseases that translate malformation and / or significant deformations of the knee and condition difficulties of application and evaluation of the results.

8. Weight overload expressed in body mass index (BMI) greater than 30.5 (obesity grade II). Being BMI = mass (Kg): (height (m)) 2

9. Active neoplastic disease.

10. Active immunosuppressive states.

11. Simultaneous participation in another clinical trial or treatment with another product in the Research phase in the 30 days prior to inclusion in the study.

12. Other pathologies or circumstances that compromise participation in the study according to medical criteri