Background: The ideal treatment for osteochondral lesions of the talus (OLTs) is still controversial, especially in older patients. Recently, mesenchymal stem cells (MSCs) have been suggested for use in the cell-based treatment of cartilage lesions. Purpose: To compare the clinical outcomes of MSC injection and arthroscopic marrow stimulation treatment with those of arthroscopic marrow stimulation treatment alone for the treatment of OLTs in older patients. Study Design: Cohort study; Level of evidence, 3. Methods: Among 107 patients with OLTs treated arthroscopically, only the patients older than 50 years (65 patients) were included in this study. Patients were divided into 2 groups: 35 patients (37 ankles) treated with arthroscopic marrow stimulation treatment alone (group A) and 30 patients (31 ankles) who underwent MSC injection along with arthroscopic marrow stimulation treatment (group B). Clinical outcomes were evaluated according to the visual analog scale (VAS) for pain, the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale, and the Roles and Maudsley score. The Tegner activity scale was used to determine outcomes in activity levels. Results: The mean VAS score in each group was significantly improved (P < .05) from 7.2 +/- 1.1 to 4.0 +/- 0.7 in group A and from 7.1 +/- 1.0 to 3.2 +/- 0.9 in group B. The mean AOFAS score in each group was also significantly improved (P < .05) from 68.0 +/- 5.5 to 77.2 +/- 4.8 in group A and from 68.1 +/- 5.6 to 82.6 +/- 6.4 in group B. There were significant differences in mean VAS and AOFAS scores between the groups at final follow-up (mean, 21.8 months; range, 12-44 months) (P < .001). The Roles and Maudsley score showed significantly greater improvement in group B than in group A after surgery (P = .040). The Tegner activity scale score was significantly improved in group B (from 3.5 +/- 0.7 to 3.8 +/- 0.7; P = .041) but not in group A (from 3.5 +/- 0.8 to 3.6 +/- 0.6; P = .645). Large lesion size (>= 109 mm(2)) and the existence of subchondral cysts were significant predictors of unsatisfactory clinical outcomes in group A (P = .04 and .03, respectively). These correlations were not observed in group B. Conclusion: Injection of MSCs with marrow stimulation treatment was encouraging in patients older than 50 years compared with patients treated with marrow stimulation treatment alone, especially when the lesion size was larger than 109 mm(2) or a subchondral cyst existed. Although still in the early stages of application, MSCs may have great potential in the treatment of OLTs in patients older than 50 years, and more evaluations of its effect should be performed.
