Mesenchymal stem cells are found in bone marrow, and have the ability to differentiate into different tissue types. The primary objective of the study is to examine the safety of using such cells to treat patients suffering from distal tibial shaft fractures. The cells will be isolated from the patient's bone marrow, loaded onto a carrier and implanted locally at the fracture site.

Inclusion Criteria:

• ages 18 and 65. males not involved in active military duty. females- non child bearing potential. distal tibia third fracture without joint involvement. fracture treated by IM nail, percutaneous plating or external fixation.

Exclusion Criteria:

• active systemic or local infection. history of malignancy radiotherapy or chemotherapy. active autoimmune disease. any past or present immunosuppressive treatment. fracture treated by open reduction. fracture grade gustillo grade IIIB, IIC. use of steroids in past 6 months. chronic renal insufficiency. administration of marrow suppressive drugs. history of metabolic bone disease. administration of drugs that may interfere with bone metabolism.