How to Inject Bone Marrow-Derived Mesenchymal Stem Cells Into Tendons and Ligaments

1. Introduction

Bone marrow–derived mesenchymal stem cells (BMDMSCs) or progenitor cells have been used for treatment of many musculoskeletal diseases in the horse. Diseases most commonly treated with the use of this therapy in the horse are tendonitis, desmitis, and joint disease.^1–4  Bone marrow is an excellent source of progenitor cells, and, although mesenchymal stem cells harvested from fat can also provide a source of progenitor cells, bone marrow– derived progenitor cells appear superior in their ability to heal musculoskeletal tissues.^5–9  The technique of harvesting BMDMSCs from ilium or sternum has previously been described.¹⁰  

The objective of this presentation is to familiarize practitioners with the technique of injecting these cells once they are culture-expanded and sent back to the practitioner. Specifically, this presentation will review the thawing, preparation, and ultrasound guidance of injecting these cells into tendon and ligaments.

2. Methods

Sedation should be performed using detomidine hydrochloride at 0.02 mg/kg and butorphanol at (dose) intravenously. Flunixin meglumine should be administered before injection at a dose of 1.1 mg/kg intravenously to decrease any inflammation associated with the injection process as well as to minimize the potential of a “flair” associated with the stem cell injection, which is reported with treatment using other biologics as well. The area to be injected should then be clipped, and an ultrasound examination is performed. The affected area should be visualized in both the horizontal and longitudinal planes. The area of the limb should then be locally anesthetized using peripheral nerve blocks with mepivicaine hydrochloride above the region of the tendon or ligament defect to minimize any movement of the limb while the ultrasoundguided injection is being performed. Alternatively, a subcutaneous local block may be performed; however, this may not adequately locally anesthetize the area, adding increased risk to the ultrasonographer, and a subcutaneous bleb of fluid may decrease the visibility of the needle passing into the lesion, using ultrasound guidance due to the fluid or potential gas.
 

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