Microfracture Versus Adipose Derived Stem Cells for the Treatment of Articular Cartilage Defects

Randomized Controlled Trial of Microfracture Versus Adipose Derived Stem Cells for the Treatment of Isolated Articular Cartilage Defects

The purpose of this study is to compare two biologic methods for the treatment of articular cartilage defects in the knee. The first method, microfracture, is the standard of care and is routinely used to recruit cells from the subchondral bone marrow to the site of cartilage loss. The second method is the application of adipose-derived stem cells (ADSCs) to the defect site. In theory, ADSCs on a collagen scaffold should enable the delivery of more specific progenitor cells to the site of injury, resulting in better regeneration and integration of articular cartilage at the site of a defect as compared to the microfracture method.

Patients enrolled in the ADSC cohort will undergo the following procedures: arthroscopic resection of approximately 5cc of the infrapatellar fat pad using a motorized shaver (standard use in arthroscopy). Fat will be collected in a sterile Aquavage Collection System (AV1200, MD Resources, Livermore, CA) and kept sealed until processing. Fat will then immediately be processed in the Harvest Adiprep System to separate a population of ADSCs. This system concentrates an average of 5 x 105 cells/ml. All specimens will be processed using routine sterile procedures within the operating room; cells destined for implantation will not leave the operating room. Concurrently, patients will undergo arthroscopy and similar preparation of the chondral defect and removal of the calcified cartilage layer. However, no puncture of the subchondral bone will be performed. A layer of fibrin glue (Tisseel) will be placed at the base of the defect to seal off any bleeding from the subchondral plate followed by the application of the acellular dermal matrix (Allopatch HD, MTF Corporation, Edison, NJ, USA)and ADSCs. An additional layer of Tisseel will then be applied over the cells and matrix. No additional fixation will be applied. The matrix and cells will be recessed below the articular surface by an average of 1mm.

They will then complete outcome questionnaires and additional MRI scans at 6, 12, and 24 months post-operatively.

Inclusion Criteria:

• Must be between ages 18 and 50 years.
• Must have a discrete, contained chondral defect less than 400mm^2 located on the medial or lateral femoral condyle
• Must have overall neutral lower limb mechanical alignment (<5 degrees varus or valgus).

Exclusion Criteria:

• Ages younger than 18 years and older than 50 years.
• If they have undergone previous chondral procedures
• If they have pre-existing osteoarthritis (Kellegren-Lawrence Grade ≥2)
• If they have a BMI >30.