What is the best current delivery method to ensure mesenchymal stem cells get to the intended target in the shoulder?
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Depends on injection technique
The best delivery method into the shoulder for mesenchymal stem cells (MSCs), PRP or other substances is based on the injection technique. The injection approach and accuracy has significant therapeutic effects when addressing pathology in joints or tendons. With reference to the shoulder, success depends on the placement of the needle into the joint space (glenohumeral or acromioclavicular) if addressing arthritis; or into the abnormality of the tendon (biceps and/or rotator cuff) for tendinosis or partial tears. Anatomic palpation to identify injection sites is helpful, but imaging leads to more precise placement of the injectate.
Even though non-imaging for glenohumeral joint injection accuracy can reach almost 100%, depending on the physician, the average accuracy when summarizing findings of multiple studies is about 79% vs. an average accuracy for imaging the same joint injection of 95%. A review by Bookman demonstrated little evidence of greater accuracy with glenohumeral intraarticular injections vs. blind injections.
However, when looking at biceps tendon injections, accuracy with ultrasound guided injections vs. landmark injections is significantly improved. Imaging can be through ultrasound, MRI or traditional fluoroscopy. For tendinosis and/or partial tears in the biceps and/or the rotator cuff, ultrasound is the best vehicle to visualize the maximum site of injury/pathology to facilitate the injection. For osteoarthritis in the glenohumeral or acromioclavicular joint, ultrasound is also effective.
- Aly AR, et al. Br J Sports Med. 2015;doi:10.1136/bjsports-2015-095213.
- Bookman JS, et al. Bull Hosp Jt Dis (2013). 2014;72:266-270.
- Daley EL, et al. Am J Sports Med. 2011;doi:10.1177/0363546510390610.
Brian C. Halpern, MD, specializes in sports medicine at Hospital for Special Surgery in New York.
Disclosure: Halpern reports he receives research support from Cytori Therapeutics Inc.
MSC injection is not FDA-approved
Using an ultrasound-guided technique is the best way for surgeons to target any shoulder injection. Surgeons who are proficient in the technique can watch the injection dynamically, monitor the precise location of the needle and observe exactly where cells are being delivered. In theory, this would be the ideal technique for injection of MSCs. The problem, however, is it is illegal to inject these cells in the United States without a FDA–approved protocol, which makes this situation complicated.
In the absence of MSC injection, there are a handful of regenerative medicine treatments available, including autologous grafts, such as bone marrow and fat aspiration, as well as different allogenic placenta products. Although these products may be touted as stem cell treatments, these actually contain minute amounts of stem cells and there is little evidence these work. There are many ongoing issues with the current status of cellular treatments for musculoskeletal injuries; while cell therapies are exciting and offer great promise, the use of these must be guided and couched under strict, intelligent clinical protocols.
C. Thomas Vangsness, MD, is a professor of orthopedic surgery at Keck Medicine of USC in Los Angeles.
Disclosure: Vangsness reports he is a paid consultant for NuTech Medical, is an unpaid consultant for Cellular Biomedicine Group, is a stockholder for Parcus Medical and is a board member for KeraLink.