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

Abstract

Background: In a previous study, the authors found that at 6 months after treatment with a 20 × 106 dose of bone marrow–derived mesenchymal stem cells (BM-MSCs), patients showed improved tendon structure and regeneration of the gap area when compared with treatment using leukocyte-poor platelet-rich plasma (Lp-PRP). The Lp-PRP group (n = 10), which had not seen tendon regeneration at the 6-month follow-up, was subsequently offered treatment with BM-MSCs to see if structural changes would occur. In addition, the 12-month follow-up outcomes of the original BM-MSC group (n = 10) were evaluated. Purpose: To evaluate the outcomes of all patients (n = 20) at 12 months after BM-MSC treatment and observe if the Lp-PRP pretreated group experienced any type of advantage. Study Design: Cohort study; Level of evidence, 2. Methods: Both the BM-MSC and original Lp-PRP groups were assessed at 12 months after BM-MSC treatment with clinical examination, the visual analog scale (VAS) for pain during daily activities and sports activities, the Victorian Institute of Sport Assessment–Patella score for patellar tendinopathy, dynamometry, and magnetic resonance imaging (MRI). Differences between the 2 groups were compared with the Student t test. Results: The 10 patients originally treated with BM-MSCs continued to show improvement in tendon structure in their MRI scans ( P < .0001), as well as in the clinical assessment of their pain by means of scales ( P < .05). Ten patients who were originally treated with Lp-PRP and then with BM-MSCs exhibited an improvement in tendon structure in their MRI scans, as well as a clinical pain improvement, but this was not significant on the VAS for sports ( P = .139). Thus, applying Lp-PRP before BM-MScs did not yield any type of advantage. Conclusion: The 12-month follow-up outcomes after both groups of patients (n = 20) received BM-MSC treatment indicated that biological treatment was safe, there were no adverse effects, and the participants showed a highly statistically significant clinical improvement ( P < .0002), as well as an improvement in tendon structure on MRI ( P < .0001). Preinjection of Lp-PRP yielded no advantages.

Recent Advances in the Use of Stem Cells in Tissue Engineering and Adjunct Therapies for Tendon Reconstruction and Future Perspectives

“…The results of a 12-month study involving participants with patellar tendinopathy showed that BMSC biologic treatment was uncomplicated and safe. The participants showed significant clinical improvements and the tendons examined by magnetic resonance imaging (MRI) showed a more organised structure [37]. Unfortunately, the disadvantage of BMSCs is an increased incidence of ectopic bone formation in the animal's tendons and reduced strength compared with tendons that were not exposed to injury [38].…”

Impact of Centrifugation Parameters on Platelet-Rich Plasma Injection for Patella Tendinopathy: A Systematic Review and Meta-Analysis

“…In total, 360 patients underwent PRP injections for PT. Overall, seven articles originated from Italy [ 2 , 4 , 5 , 12 - 15 ]; two each from the USA [ 11 , 16 ], France [ 17 , 18 ], and the Netherlands [ 19 , 20 ]; and one each from Egypt [ 21 ], Turkey [ 10 ], and Spain [ 22 ], as well as a multicenter study that involved hospitals in Italy, Norway, and the USA [ 23 ]. A summary of the study characteristics of the included articles can be found in Table 1 .…”

Role of orthobiologics in managing patellar tendinopathy: A narrative review

“…After a mean follow‐up period of 5 years, there was a statistically significant improvement in Tegner score, IKDC score and Knee injury and Osteoarthritis Outcome Score symptoms, activities of daily living and sport. Soler et al [ 32 ], did a prospective comparative study between bone marrow‐derived mesenchymal stem cells (BM‐MSCs) and LP‐PRP in 20 patients with chronic patellar tendinopathy. In the first phase of the study, BM‐MSC injection and PRP injection were given to 10 patients each.…”