Over the years we have seen a lot of people with knee problems. Many of them with problems of the patellar tendon. They have had many treatments including, cortisone, physical therapy, rest, some of the them wear big braces on their knees. Can stem cell therapy help them?
- Stem cell therapy involves the use of your own bone marrow derived stem cells within a regenerative injection program.
Stem Cell Therapy for Patellar Tendinopathy research
A recent study (1) from Stanford University focused on additional treatment options for patellofemoral pain syndrome, and patellar tendinopathy. The researchers discuss tape, brace, and Prolotherapy, PRP and Stem Cell injections
- Recent studies of bracing and taping have found them to be helpful for patients in the short-term management of pain and improving function.
- Injections remain a commonly used treatment for musculoskeletal conditions; however, the evidence for their use in patellofemoral pain and patellar tendinopathy is limited. The use of platelet-rich plasma (PRP), sclerosing (prolotherapy), or stem cell injections is an exciting new area in the treatment of patellar tendinopathy.
I point out this study because many of the people that come into our office have heard something similar in their orthopedisit’s office. Wear a brace if it helps, there is no evidence that stem cells can help you. So the first thing many of the people who eventually come to visit is ask is, “Is there any research on stem cells for patellofemoral pain syndrome, and patellar tendinopathy?” I also want to point out that these same people who come visit us are people who have been on anti-inflammatories, wrap up their legs in ace bandages, ice, may have had a cortisone injections and nothing is really helping. They are here because for some of them are willing to take a chance on stem cells.

But is there any research?
A December 2018 study examined the role of mesenchymal stem cells in the treatment of tendinopathies.(2) The investigators of this study wrote: “Although (research) attention was mainly focused on their (the stem cell’s) ability to differentiate (change into needed repair cells) and to directly participate to the regeneration process in the past, mesenchymal stem cells have more recently been demonstrated to have further and probably more important therapeutic functions in response to injury like immune modulation and trophic (promoting cellular growth) activities. Stem cells can hone in on sites of inflammation or tissue injury where they start to secrete immunomodulatory and trophic agents such as cytokines and growth factors aimed to re-establish physiological homeostasis in response to that environment. (In simpler terms stem cells can act as an anti-inflammatory and pro-healing agent). So, either as direct player in the process or/and bioactive molecules, mesenchymal stem cells may enhance tissue repair and regeneration and thereby restore normal joint homeostasis.”
A well referenced and cited study from 2012 (3) followed eight mid-20s aged athletes with chronic patellar tendon degeneration. These patients received bone marrow stem cell therapy. The stem cells were taken from the patient’s iliac bone crest and injected into the problem knee. These patients were then followed for 5 years to measure the long-term results of the treatment. Here were the published results:
- “At 5-year follow-up, statistically significant improvement was seen for most clinical scores.
- Seven of eight patients said they would have the procedure again if they had the same problem in the opposite knee and were completely satisfied with the procedure.
- Seven of 8 patients thought that the results of the procedure were excellent. According to our results, (bone marrow stem cells should be) considered as a potential therapy for those patients with chronic patellar tendinopathy refractory to nonoperative treatments.”
A September 2023 study (4) followed up previous research which found that at 6 months post-treatment with bone marrow–derived mesenchymal stem cells, ten patients showed improved tendon structure and regeneration when compared with treatment using leukocyte-poor platelet-rich plasma. Later, the leukocyte-poor platelet-rich plasma group (10 patients), which had not seen tendon regeneration at the 6-month follow-up, was subsequently offered treatment with bone marrow–derived mesenchymal stem cells to see if structural changes would occur. In addition, the 12-month follow-up outcomes of the original bone marrow–derived mesenchymal stem cells were evaluated. The 12-month follow-up outcomes after both groups of patients received bone marrow–derived mesenchymal stem cells treatment indicated that biological treatment was safe, there were no adverse effects, and the participants showed a highly statistically significant clinical improvement as well as an improvement in tendon structure on MRI.
Bone Marrow Aspirate Concentrate (BMAC) – Stem Cell Therapy – Grade III chondromalacia patellae
An April 2024 study (5) discussed the case of a 36-year-old man who had Grade III chondromalacia patellae. The patient didn’t respond to conventional treatments, but he did get better with Bone Marrow Aspirate Concentrate (BMAC) therapy. After six and twelve weeks of this therapy, the patient felt a lot less pain and was able to do more things. This 36-year-old works as a laborer and has to lift heavy weights. He had been dealing with pain in his right knee for more than a year. The pain started after he fell over a year ago.
Before stem cell treatment the patient reported complaints of excruciating pain over the right knee for 1.5 years, limited range of motion, along with a giving away sensation of the right knee for four months. Following clinical pain (Pain was 8 out of 10) and poorer functional assessments, and finally imaging, the patient was diagnosed to have Grade III chondromalacia of the right patella.
After using non-steroidal anti-inflammatory drugs (NSAIDs) and doing physical therapy for a few weeks, his knee pain got better. But about six months before his last visit, he had a return of pain in the front of his knee. Standing, walking, and exercising made it hurt more, but resting helped ease the pain. Unlike before, treatments like physiotherapy and NSAIDs didn’t help this time. Bone Marrow Aspirate Concentrate (BMAC) was suggested.. “This case shows how BMAC therapy could be a good option for treating cartilage problems, offering a less invasive way with good results,” the doctors said. They also mentioned, “But to prove that BMAC is a reliable and effective treatment, we need bigger clinical trials with longer follow-ups and control groups.” This above research is a single case history.
References
1 Sisk D, Fredericson M. Taping, bracing, and injection treatment for patellofemoral pain and patellar tendinopathy. Current Reviews in Musculoskeletal Medicine. 2020 Aug;13(4):537-44.
2 Abat F, Alfredson H, Cucchiarini M, Madry H, Marmotti A, Mouton C, Oliveira JM, Pereira H, Peretti GM, Spang C, Stephen J. Current trends in tendinopathy: consensus of the ESSKA basic science committee. Part II: treatment options. Journal of experimental orthopaedics. 2018 Sep 24;5(1):38.
3 Pascual-Garrido C, Rolón A, Makino A. Treatment of chronic patellar tendinopathy with autologous bone marrow stem cells: a 5‐year‐followup. Stem cells international. 2012;2012(1):953510.
4 Soler R, Rodas G, Rius-Tarruella J, Alomar X, Balius R, Ruíz-Cotorro Á, Masci L, Maffulli N, Orozco L. Safety and Efficacy of Bone Marrow–Derived Mesenchymal Stem Cells for Chronic Patellar Tendinopathy (with Gap> 3 Mm) in Patients: 12-Month Follow-up Results of a Phase 1/2 Clinical Trial. Orthopaedic Journal of Sports Medicine. 2023 Sep 8;11(9):23259671231184400.
5 Soundharya V, Arthi R, Haran H, Kumar S, James S. Enhanced Bone Marrow Aspirate Concentrate (BMAC) Preparation Strategy in the Management of Chondromalacia Patella: A Case Report. Cureus. 2024 Apr 29;16(4).
Marc Darrow, M.D., J.D., is one of the world’s most experienced Regenerative Medicine doctors. He has more than 30 Years of expertise in regenerative medicine techniques and has treated thousands of patients. He uses non-surgical therapy to reduce pain in joints, tendons, ligaments, and a variety of other ailments and disorders throughout the body, including back and neck discomfort. He taught at UCLA and received Board Certification in Physical Medicine and Rehabilitation.





