Mesenchymal Stem Cell Augmentation in Patients Undergoing Arthroscopic Rotator Cuff Repair

A Prospective Randomized Trial of Biologic Augmentation With Mesenchymal Stem Cells in Patients Undergoing Arthroscopic Rotator Cuff Repair

The primary objective of this study is to compare the clinical outcomes of arthroscopic rotator cuff repair with and without augmentation of mesenchymal stem cells (MSCs). Mesenchymal stem cells promote tissue regeneration by differentiating into adult cell lines and by supplying growth factors to their implanted environment. They have been shown to be effective in improving both overall healing and tendon integrity in rotator cuff repair. This study will follow 100 patients in the United States and track their clinical outcomes for at least one year post-operatively.

Rotator cuff repair is one of the most commonly performed arthroscopic procedures in the United States, but re-tear remains a common long-term complication. This can lead to pain, decreased shoulder function, and the need for corrective surgery. Mesenchymal stem cells have been shown to improve healing rates in arthroscopic rotator cuff repair, primarily due to their retained ability to differentiate into several different adult cell lines, such as tenocytes, chondrocytes, and osteoblasts. MSCs further enhance the healing process by releasing growth factors into the local environment to promote tissue regeneration. While MSC augmentation of arthroscopic rotator cuff repair has led to higher rates of healing and improved tendon integrity, there remains a paucity of data surrounding clinical improvement after the procedure. Outcomes such as post-operative strength, range of motion, and shoulder function have yet to be compared with standard rotator cuff repair. The incidence of post-operative persistent structural defects in the tendon after MSC augmentation must also be further elucidated.

Using clinically accepted methods, subjects will undergo bone marrow aspiration (from hip, proximal humerus or tibia) through a small incision prior to arthroscopy in the group undergoing MSC augmentation. They will then undergo arthroscopic full thickness rotator cuff repair using a double row, TOE anchor/suture technique with mesenchymal stem cell augmentation.

Subjects will undergo arthroscopic full thickness rotator cuff repair using a double row, TOE anchor/suture technique, without augmentation of mesenchymal stem cells. To maintain patient blinding, all patients will receive a small incision around the site of expected bone marrow aspiration (hip, proximal humerus, or tibia), regardless of whether or not they receive bone marrow.

Patients undergoing mesenchymal stem cell augmentation will receive a total injection of 6 milliliters (mL). Of this, 3 mL will be injected in the tendon at the junction between bone and tendon, while 3 mL will be injected in the bone at the site of the surgical footprint.

All patients will undergo full thickness rotator cuff repair using a double row, transosseous-equivalent (TOE) repair with anchor/suture technique. Acromioplasty will be performed in all patients. Alternate procedures such as biceps tenotomy/tenodesis and distal clavicle excision will be performed at the discretion of the surgeon and recorded.

To assess for persistent structural tendon defects and to determine the integrity of the repair with comparisons to pre-operative MRI anatomy and tear description at the time of surgery.

Patients will be administered validated patient reported outcome measures post-operatively. These include a Visual Analog Scale (VAS) pain score, Constant score, Simple Shoulder Test, Single Assessment Numeric Evaluation (SANE) score, and the 12-Item Short Form Health Survey (SF-12).

Inclusion Criteria: Patient is determined to have a full thickness rotator cuff tear (1-3 cm) or partial tear converted to a full-thickness tear-on the pre-operative MRI scan or found arthroscopically-and is scheduled to undergo surgical repair Written informed consent is obtained Exclusion Criteria: Revision surgery Irreparable tear or partial repair Any patient lacking decisional capability Subscapularis involvement

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