BACKGROUND

Bone-to-tendon healing in the shoulder can be unpredictable. Biologic augmentation, through the implementation of adult mesenchymal stem cells, may improve this healing process.

PURPOSE

The purpose of this study was to (1) arthroscopically obtain bone marrow aspirates from the proximal humerus during rotator cuff repair, (2) purify and concentrate the connective tissue progenitor cells (CTPs) in the operating room efficiently, and (3)confirm these are stem cells through their ability to differentiate into bone cells. We hypothesize that CTPs can be quickly and efficiently isolated from bone marrow during arthroscopic surgery and that these cells are capable of osteogenesis.

STUDY DESIGN

Cohort study; Level of evidence, 3; and Descriptive laboratory study.

METHODS

Bone marrow aspirates were harvested through the anchor tunnel of the humeral head during arthroscopic rotator cuff repair in 23 patients. Twenty-three matched controls were selected from a clinical registry to evaluate for increased incidence of complication. Connective tissue progenitor cells were isolated using 2 accepted methods and compared with a novel, rapid method designed for use in the operating room. Osteogenic potential was assessed by cytochemical and molecular analysis.

RESULTS

Reverse transcription polymerase chain reaction analysis and cellular staining confirmed the osteogenic potential of these CTPs. There was no statistical significant difference in the Single Assessment Numeric Evaluation score (aspirate, 86.3 +/- 10.5; control, 83.6 +/- 15.1; P = .54), range of motion measures (postoperative external rotation: aspirate, 65.0 degrees +/- 20.4 degrees ; control, 62.5 degrees +/- 17.1 degrees ; P = .67; postoperative forward elevation: aspirate, 163.0 degrees +/- 30.6 degrees ; control, 145.7 degrees +/- 41.4 degrees ; P = .12), or postoperative strength measures between groups (median, 5; range, 4-5 in the aspirate group compared with median, 5; range, 4-5 in the control group; P > .05).

CONCLUSION

Connective tissue progenitor cells can be safely and efficiently aspirated from the proximal humerus using the anchor tunnel created during arthroscopic rotator cuff surgery. These cells may play an important role in cell-based therapies involving rotator cuff repair.

CLINICAL RELEVANCE

We have established a reliable, reproducible protocol for isolating CTPs in the operating room. These cells may have the potential to enhance the healing process after rotator cuff repair.