Marc Darrow, MD, JD.

I get a lot of emails. In some of the emails the writer will recount to me that they had PRP treatment for a rotator cuff tear and it did not work. There are a lot of times Platelet-rich plasma for a rotator cuff will not work. One way it will not work is if you get a single Platelet-rich plasma injection into the shoulder, more or less at random, and then one month later you get it again. That is the way many doctors offer Platelet-rich plasma treatment. That is not the way we do PRP therapy injections for the shoulder.

In the American Journal of Sports Medicine, July 2019, (1) a team of doctors in Switzerland tried the one injection, repeated a month later type of PRP treatment for a rotator cuff tear. More specifically for an Interstitial Supraspinatus Tear, the tendon of the Supraspinatus muscle of the rotator cuff. One of the rotator cuff muscles. It should be noted that in this study, ultrasound was used to guide the single injection to the damaged injury site.

The PRP injection was given to some of the study participants and some participants acting as a “control” group received a simple saline injection. So what happened? The PRP did not work any better than the saline solution. Why? When I see someone in our office with shoulder pain and shoulder instability, an examination will usually reveal that there are many things going on in the shoulder beyond a single or isolated tear of the Supraspinatus tendon (the tendon itself has only one tear), and that the shoulder itself is a degenerating joint.

In the Orthopaedic journal of sports medicine, (2) researchers noted that in Partial articular supraspinatus tendon avulsion (PASTA) tears are often seen in shoulders of throwing athletes who have recurrent anterior glenohumeral (shoulder) instability. In other words, there are many things going on at once, isolating out one injury in the shoulder will not solve a problem of total shoulder breakdown. In the shoulder rotator cuff injuries usually do not occur as an isolated tear. There is a lot going on in rotator cuff injuries.

Cortisone and PRP

A November 2019 study published in the Journal of back and musculoskeletal rehabilitation (3) compared cortisone injections (pain management) and PRP injections. The results of this comparative study found in “patients with rotator cuff lesions (tears), corticosteroid injection provides short-term relief for pain, function, and quality of life, while PRP injection works for long-term wellbeing.”

PRP injections or corticosteroid injections?

A March 2022 study (4) compared PRP injections to corticosteroid injections for rotator cuff tendinopathy. The patients in this study were followed for 18 months after treatment.

Here is what the study noted: “Given the complications involved in corticosteroid injections, subacromial platelet-rich plasma (PRP) injections may provide a valid alternative to corticosteroid injections in the treatment of rotator cuff .tendinopathy.”

Ninety-eight patient charts were reviewed with the patients being treated with either subacromial injection of PRP or corticosteroid. The PRP group received three injections of autologous PRP at 2 weeks interval, and the corticosteroid group received one injection. “Both treatments improved patient symptoms, but neither resulted in a significantly better outcome in this series of patients. PRP can be a safe and feasible alternative to corticosteroid, even at long-term follow-up, to reduce local and systemic effects involved with corticosteroid injections.”

The platelets contain healing agents, or “growth factors.” Let’s look at some of the growth factors and what they do:

  • Platelet-derived growth factor (PDGF) is a protein that helps control cell growth and division, especially blood vessels. When more blood (and the oxygen it carries) is delivered to the site of a wound, there is more healing.
  • Transforming growth factor beta (or TGF-β) is a polypeptide and is important in tissue regeneration.
  • Insulin-like growth factors are signaling agents. They help change the environment of the damaged joint from diseased to healing by “signaling” the immune system to start rebuilding tissue.
  • Vascular endothelial growth factor (VEGF) is an important protein that brings healing oxygen to damaged tissue where blood circulation might be damaged or inadequate.
  • Epidermal growth factor plays a key role in tissue repair mechanisms.

A paper (5) evaluating the effectiveness of autologous platelet-rich plasma (PRP) injections in the treatment of common shoulder diseases. To do this the researchers examined previously published randomized controlled trials of PRP versus a control.

  • From 8-12 weeks to more than 1 year, PRP injections were associated with better pain relief and functional outcomes than control interventions.
  • PRP injections were also associated with greater quality of life.
  • Compared with placebo and corticosteroid injections, PRP injections provided better pain relief and functional improvement.

Conclusions: “PRP injections could provide better pain relief and functional outcomes than other treatments for persons presenting with common shoulder diseases. PRP injections have a greater capacity to improve shoulder-related quality of life than other interventions.”

PRP injections vs placebo, no injection, or physical therapy

A March 2020 study (6) investigated the effectiveness of platelet-rich plasma (PRP) injection among patients with rotator cuff tendinopathy in comparison with sham injection, no injection, or physiotherapy alone.

These types of studies comparing one injection of PRP versus other injections are not typical in the demonstration of effectiveness of how PRP should be administered based on our years of clinical observation. While one injection of PRP can help many people, it can equally not demonstrate good results. PRP treatment is typically a multi-injection treatment.

These researchers found “in the short term (3-6 weeks) and medium term (12 weeks), the effectiveness of PRP injection and control group was indistinguishable in terms of both outcomes (pain reduction and functional improvement). Nevertheless, PRP injection led to significant long-term (more than 24 weeks) pain relief.”

Conclusion of this research: “PRP injection may provide benefit over the control group (sham injection, no injection, or physiotherapy alone) in reducing pain at long-term follow-up for patients with rotator cuff tendinopathy.”

No consensus regarding treatment of partial thickness tears that fail conservative treatment

More recently a May 2021 study (7) examined the problem of “no consensus regarding treatment of partial thickness tears that fail conservative treatment.” The purpose then of this study was to assess the effectiveness and safety of two injections of PRP into the rotator cuff who have failed other conservative treatments with follow up two years after the PRP treatments. The conclusion of This study was “PRP injection is a safe and effective treatment for rotator cuff injury in patients who have failed conservative treatment of activity modification and physical therapy without deterioration of results two years after treatment. Better results are obtained with greater structural tendon damage than in shoulders with inflammation without structural damage.”

In a July 2021 study (8), study researchers wrote: “Rotator cuff tendinitis has been treated using various methods including physiotherapy, steroid injections and recently platelet rich plasma (PRP). Most of these methods aim at giving symptomatic relief rather than addressing the pathology (the cause of the problem). There is no clear consensus over the benefit of using PRP for tendinitis. (The authors) decided to do a prospective clinical study to demonstrate the efficacy of PRP and study the functional outcome in the treatment of rotator cuff tendinopathy.

  • Patients with shoulder pain for more than three months not responding to NSAIDs or physiotherapy with a diagnosis of rotator cuff tendinitis, confirmed by MRI, were included in the study.
  • Patients with rotator cuff tear or any other shoulder pathology were excluded. (The researchers were looking only at problems of tendinitis).
  • Thirty patients received 5ml an ultrasound guided PRP injection in the subacromial space followed by a six-week exercise program.
  • Patients were followed-up at three, six and 12 weeks and were assessed clinically using the Pain and functional scoring systems.

The ten point Visual Analogue System score 0 being no pain and 10 being unbearable pain improved from a pre injection score of 7.4 (significant pain) to a score of 1.9 (little pain) in the 12th week. The mean SPADI (Shoulder Pain and Disability Index) score and Constant (pain and shoulder rotation score the lower the number the better) score improved significantly.

Conclusion: “Platelet Rich Plasma injections showed good to excellent early results, in patients with rotator cuff tendinopathy with improvement in VAS, SPADI and Constant scores.”

Two PRP injections into the same shoulder works better and lasts at least two years

A May 2021 study (9) suggests “PRP injection is a safe and effective treatment for rotator cuff injury in patients who have failed conservative treatment of activity modification and physical therapy without deterioration of results two years after treatment. Better results are obtained with greater structural tendon damage than in shoulders with inflammation without structural damage.” The study authors add: “The most important findings of this study are that dual rotator cuff PRP injection is safe and produces consistently beneficial results in patients with partial rotator cuff tears that have failed conservative treatment. The results continued to show benefits at two years after the initial injection. None of the treated patients presented with an increase in symptoms that would indicate progression of rotator cuff pathology from partial to full thickness tear. This is the first study to show sustained improvement out to two years post injection. It is the first to report dual injection of the rotator cuff. In our opinion, (our) study helps establish PRP injection as the preferred treatment for partial rotator cuff tears that fail activity modification and physical therapy.”

Comparing single platelet-rich plasma injection with hyaluronic acid injection for partial-thickness rotator cuff tears

A June 2022 (10) paper presented a prospective, nonrandomized, comparative study. The aim of the study was to compare the effects of ultrasound-guided single PRP injection with three doses of hyaluronic acid injection, combination of post-injection rehabilitation, for treating partial-thickness rotator cuff tears. The people of this study received either ultrasound-guided PRP injection and rehabilitation exercise, or ultrasound-guided subacromial hyaluronic acid injection and rehabilitation exercise. Shoulder Pain and Disability Index (SPADI), range of motion (ROM), pain visual analog scale (VAS), and Constant-Murley Shoulder Score (CMSS) were recorded before injection, and at 1 and 3 months after injection.

In the PRP group, pain and function scores significantly improved at 1-month and 3-month follow up; flexion and abduction range of motion significantly increased at 3-month follow up. In the hyaluronic acid injection group, pain and function scores also significantly improved in the first and third months; flexion and active abduction range of motion significantly increased in the third month. The PRP group revealed significantly better passive abduction range of motion  at third month than the hyaluronic acid injection group.

Conclusion: “Ultrasound-guided single PRP injection exhibited comparable benefit to three doses of hyaluronic acid injection in patients with partial-thickness rotator cuff tears short-termly, with an extended effect regarding passive shoulder abduction range of motion and functionality.

“PRP does seem to play an effective role in significantly reducing the re-tear rate in acute rotator cuff tears”

A June 2022 paper (11) suggested: “PRP does seem to play an effective role in significantly reducing the retear rate in acute rotator cuff tears and in preventing full-blown large tears in chronic rotator cuff tendinopathies. Since the retear rates after an arthroscopic repair of rotator cuff tear continue to be quite high, biologic methods of managing rotator cuff pathologies like PRP are gaining traction since they are said to improve bone-tendon healing, thereby reducing the chances of rupture, tear, or retears.”

In an editorial in the journal Arthroscopy (12) Dr. Eric Hoffman offers this viewpoint: “Studies investigating the effect of PRP on shoulder rotator cuff healing, clinical outcomes, and retear rates suggest that PRP has no effect on outcome and healing but potentially reduces re-tear rates. However, study quality is compromised . . . Until there are reliable and valid data available, the use of PRP in rotator cuff repair is not strongly supported and is at the discretion of the treating surgeon. The current evidence shows the superiority of PRP over hyaluronic acid and corticosteroids, and there is promise that PRP could be a useful adjunct promoting rotator cuff healing following surgical repair.”

References
1 Schwitzguebel AJ, Kolo FC, Tirefort J, Kourhani A, Nowak A, Gremeaux V, Saffarini M, Lädermann A. Efficacy of platelet-rich plasma for the treatment of interstitial supraspinatus lesions: A randomized, double-blinded, controlled trial: PRP for Interstitial Supraspinatus Lesions. Orthopaedic Journal of Sports Medicine. 2019 May 31;7(5_suppl3):2325967119S00210.
2 Ueda Y, Sugaya H, Takahashi N, Matsuki K, Tokai M, Hoshika S, Onishi K, Hamada H. Prevalence and Site of Rotator Cuff Lesions in Shoulders With Recurrent Anterior Instability in a Young Population. Orthop J Sports Med. 2019 Jun 4;7(6):2325967119849876. doi: 10.1177/2325967119849876. PubMed PMID: 31211152; PubMed Central PMCID: PMC6552367.
3 Sari A, Eroglu A. Comparison of ultrasound-guided platelet rich plasma, prolotherapy, and corticosteroid injections in rotator cuff lesions. Journal of back and musculoskeletal rehabilitation. 2019 Nov 8(Preprint):1-0.
4 Annaniemi JA, Pere J, Giordano S. Platelet-rich plasma versus corticosteroid injections for rotator cuff tendinopathy: a comparative study with up to 18 months follow-up. Journal of the Korean Shoulder and Elbow Society. 2022 Jan 4.
5 Barman A, Mishra A, Maiti R, Sahoo J, Thakur KB, Sasidharan SK. Can platelet-rich plasma injections provide better pain relief and functional outcomes in persons with common shoulder diseases: a meta-analysis of randomized controlled trials. Journal of the Korean Shoulder and Elbow Society. 2021 Oct 15.
6 Lin MT, Wei KC, Wu CH. Effectiveness of platelet-rich plasma injection in rotator cuff tendinopathy: a systematic review and meta-analysis of randomized controlled trials. Diagnostics. 2020 Apr;10(4):189.
7 Prodromos CC, Finkle S, Prodromos A, Chen JL, Schwartz A, Wathen L. Treatment of Rotator Cuff Tears with platelet rich plasma: a prospective study with 2 year follow‐up. BMC Musculoskeletal Disorders. 2021 Dec;22(1):1-3.
8 Pritem AR, Abraham VT, Krishnagopal R. Early Clinical and Functional Outcome of Rotator Cuff Tendinopathy of the Shoulder Treated with Platelet Rich Plasma Injection. Malaysian Orthopaedic Journal. 2021 Jul;15(2):55.
9 Prodromos CC, Finkle S, Prodromos A, Chen JL, Schwartz A, Wathen L. Treatment of Rotator Cuff Tears with platelet rich plasma: a prospective study with 2 year follow‐up. BMC Musculoskeletal Disorders. 2021 Dec;22(1):1-3.
10 Huang SH, Hsu PC, Wang KA, Chou CL, Wang JC. Comparison of single platelet-rich plasma injection with hyaluronic acid injection for partial-thickness rotator cuff tears. Journal of the Chinese Medical Association. 2022 Jun 1;85(6):723-9.
11 Bhan K, Singh B. Efficacy of Platelet-Rich Plasma Injection in the Management of Rotator Cuff Tendinopathy: A Review of the Current Literature. Cureus. 2022 Jun 20;14(6).
12 Hohmann E. Editorial Commentary: Platelet-Rich Plasma Reduces Retear Rates Following Rotator Cuff Repair but Does Not Improve Clinical Outcomes. Arthroscopy: The Journal of Arthroscopic & Related Surgery. 2022 Aug 1;38(8):2389-90.