Promising improvement of chronic lateral elbow tendinopathy by using adipose derived mesenchymal stromal cells: a pilot study

PURPOSE: Study the effect of Adipose derived stromal cells (ASCs) injection as therapeutic procedure on the common extensor tendinopathy. METHODS: Eighteen Tennis players with chronic, recalcitrant LET (who have previously been unsuccessfully treated with nonoperative treatments) underwent clinical evaluation and magnetic resonance imaging (MRI) before intervention. Stromal vascular fraction cells (SVF) were expanded by in vitro culture and ASCs were obtained and characterized by flow cytometry. ASCs were injected into the site of tendinopathy (identified by ultrasound imaging at the origin of the common extensor tendon) on a single occasion followed by physiotherapy. Players underwent serial clinical evaluations during a 12-month period and repeated MRI at 6-month post-injection. RESULTS: At 6-month clinical evaluation revealed significant improvements compared to baseline in mean Visual Analog Scale (VAS) scores for: (1) maximum pain score (from 6.28 ± 1.65, to 1.0 ± 0.43; p < .001); (2) Mean quick Disabilities of the Arm, Shoulder and Hand (QuickDASH-Compulsory score: 51.38 ± 12.02 to 12.33 ± 4.66; p < .001); (3) QuickDASH-Sport score: 56.94 ± 15.44 to 8.68 ± 8.86; p < .001). Validated MRI scoring system grade of tendinopathy also improved significantly: 4.22 ± 0.26 to 2.22 ± 0.10 (p < .001). At 12-month from injection, VAS maximun pain score further decreased to 0.74 ± 0.44 (p < .001) and QuickDASH-Compulsory score to 5.56 ± 3.58 (p < .001). Average time to return to play tennis was 3,31 ± 0,61 month post-intervention. CONCLUSION: Tennis players with recalcitrant LET showed significant clinical improvement and structural repair at the origin of the common tendon origin after injection of autologous ASCs. Results of this study are promising and open a new biological therapeutic modality to treat LET. Even if the results of this pilot study are positive, future well-designed studies, i.e. prospective randomized trials are needed to define the role of cell therapy in treating LET.