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

Robert Soler; Gil Rodas; Joan Rius-Tarruella; Xavier Alomar; Ramon Balius; Ángel Ruíz-Cotorro; Lorenzo Masci; Nicola Maffulli; Lluís Orozco

doi:10.1177/23259671231184400

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

Orthop J Sports Med. 2023 Sep 11;11(9):23259671231184400. doi: 10.1177/23259671231184400. eCollection 2023 Sep.

Authors

Robert Soler¹, Gil Rodas^{2

3}, Joan Rius-Tarruella¹, Xavier Alomar⁴, Ramon Balius⁵, Ángel Ruíz-Cotorro^{6

7}, Lorenzo Masci⁸, Nicola Maffulli^{9

10

11}, Lluís Orozco¹

Affiliations

¹ Institut de Teràpia Regenerativa Tissular (ITRT), Centro Médico Teknon Hospital, Barcelona, Spain.
² Medical Department FC Barcelona, Barcelona, Spain.
³ Sports Medicine Unit, Clínic Hospital and Sant Joan de Déu Hospital, Barcelona, Spain.
⁴ Diagnóstico por la Imagen, Clínica Creu Blanca, Barcelona, Spain.
⁵ Consell Català de l'Esport, Generalitat de Catalunya, Barcelona, Spain.
⁶ Servicios Médicos de la Real Federación Española de Tenis (RFET), Barcelona, Spain.
⁷ Director de la Clínica Tenis Teknon, Centro Médico Teknon, Barcelona, Spain.
⁸ Institute of Sports Exercise and Health (ISEH), London, UK.
⁹ Department of Musculoskeletal Disorders, University of Salerno School of Medicine, Surgery and Dentistry, Salerno, Italy.
¹⁰ Center of Sports and Exercise Medicine, Queen Mary University of London, London, UK.
¹¹ School of Pharmacy and Bioengineering, Keele University School of Medicine, Staffordshire, UK.

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.

Keywords: jumper’s knee; mesenchymal stem cells; patellar tendinopathy; regenerative medicine; sports injury.