Tendon healing after rotator cuff repairs is a slow process. After surgery, patients are in a special abduction sling (looks like a square-shaped pillow under the arm). They have to wear this contraption for four to six weeks.
Some passive movements are allowed while wearing the brace but not all. It isn’t until the patient is weaned off the sling that active motion can begin. Then it takes another four to six weeks before strengthening exercises can begin. And finally, for those who are engaged in recreational or sports activities, return to these activities is allowed six to nine months after surgery.
The question often comes up (especially in sports athletes): is there any way to speed up recovery time? Surgeons are aware that the retear rate of repaired rotator cuffs is pretty high during those first three months. That’s why patients are put in an immobilizer and only allowed to do some passive motion. No tension is allowed on the surgically sutured tendon. Without some outside agent to help accelerate healing, the answer to the question is “no.”
That’s where this study comes in. There is one biologic product called platelet-rich plasma (PRP) that has been used to speed up tendon healing in other areas (e.g., elbows). Orthopedic surgeons from Seoul, Korea compared two groups of patients with full-thickness rotator cuff tears.
One group (19 patients) was treated with platelet-rich plasma (PRP). The second group (23 patients) had the repair surgery without the PRP. The patients in the two groups were very similar in age, sex (males and females), size of the tear, length of time between tear and surgical repair, and hand dominance.
Platelet-rich plasma (PRP) is the portion of your blood that contains the clear fluid and extra platelets. The platelets are the part of the red blood that contain growth factors known to accelerate or speed up healing. Studies show that PRP helps many types of tissue regenerate such as bone, ligament, cartilage, muscle, and of course, tendon.
The way they inserted the platelet-rich plasma (PRP) was to thread tiny gel packs filled with the fluid onto the sutures. Then they reattached the torn tendon to the bone with the PRP gel packs between the repaired tendon and the bone. The gel packs disintegrated leaving the PRP in place where it could release the growth factors to aid the healing tissue.
In this study, they compared the results between the two groups by measuring pain, range-of-motion, strength, function, and overall satisfaction. All measures were taken before surgery and again at regular intervals for at least 16 months. An MRI was also taken after surgery to get a look at the condition of the repaired tendon.
Despite their hypothesis that the platelet-rich plasma group would have better results, there were no clear differences in any of the measured outcomes between the two groups. In fact, at the three-month mark, the group without platelet-rich plasma (PRP) had slightly better results. Over time, the differences evened out.
Pain relief and improved motion was similar in both groups. The persistent loss of external shoulder rotation was also similar between the two groups. Muscle strength improved equally in both groups. In fact, patients were equally satisfied with results in both groups. And there weren’t any harmful effects of using the PRP gels.
It’s tempting to ask, “What went wrong?” The expectation was for better results in the platelet-rich plasma (PRP) group and that isn’t what happened. Maybe nothing went wrong. The authors suggested that maybe there weren’t enough patients in the study to really measure differences in clinical results. The research term for that phenomenon is to say that the study was underpowered.
Other reasons for the initial delay in healing in the PRP group included the fact that this group did have more patients with larger tears and rehab was started slightly later than in the conventional group (group without PRP).
The authors also suggested that the dose of PRP they used wasn’t enough or that the placement of the gel packs could be a factor. It’s also possible that the way the arthroscopic surgery must be done (running fluid through the joint) could wash away too much of the PRP to make a difference. Swelling after surgery is another potential factor.
This was the first study to look at the use of platelet-rich plasma (PRP) in arthroscopic rotator cuff repairs. There is a need for further study in this area before concluding that PRP doesn’t work or isn’t effective in accelerating healing of surgically repaired full-thickness rotator cuff tears. Maybe it would work better in partial-thickness rotator cuff tears. There were fewer retears after surgery in the PRP group so that’s something that needs to be investigated further as well.