The present study evaluates the effect of XCEL-MT-OSTEO-ALPHA in non-union fractures (pseudoarthrosis) of long bones in comparison to the standard treatment of autologous iliac crest.

XCEL-MT-OSTEO-ALPHA is a tissue engineering product composed by "ex-vivo" expanded autologous mesenchymal stromal cells fixed in allogenic bone tissue, produced by Xcelia (Blood and Tissue Bank of Catalonia).

The working hypothesis proposes that the tissue engineering is a valid and useful technique to achieve bone regeneration up to consolidation of non-union fractures.

A phase IIa, single center, prospective, randomized, parallel, two-arms, single-dose, open-label with blinded assessor pilot clinical trial to assess ex vivo expanded adult autologous mesenchymal stromal cells fixed in allogeneic bone tissue (XCEL-MT-OSTEO-ALPHA) in non hypertrophic pseudoarthrosis of long bones.

Inclusion Criteria:

• 18 to 85 years of age (male and female)
• Atrophic or hypotrophic metaphyseal-diaphyseal pseudarthrosis of long bones, confirmed radiographically.
• Signed Informed Consent Form
• The patient is able to understand the nature of the study

Exclusion Criteria:

• Suspicious of pseudarthrosis focus infection diagnosed by clinical inspection and blood analysis.
• Positive serology for HIV (Anti-HIV I/II-Ac), Hepatitis B (HBsAg, HBcAc), Hepatitis C (Anti-HCV-Ac) or Syphilis Lúes (TP-Ac).
• Significant abnormal laboratory tests that contraindicates patient's participation in the study.
• Pregnant woman or without proper anticonceptive measures according to the investigator, or breath feeding
• Smoker of more than 15 cigarettes a day
• Congenital disorders of bones (hypophosphatemia), bone metabolic disorders associated to primary or secondary hypoparathyroidism.
• Badly managed diabetes mellitus.
• Patients diagnosed with peripheral arterial disorders
• Previous therapeutic radiation (5 previous years) of the affected bone.
• Neoplasia within the previous 5 years, or without remission
• The patient is legally dependent
• Participation in another clinical trial or treated with an investigational medicinal product the previous 30 days
• Other pathologic conditions or circumstances that difficult participation in the study according to medical criteria
• The patient does not accept to be followed-up for a period that could exceed the clinical trial length

Radiologist will assess images in a blinded manner