Background: The critical lesion size treated with bone marrow stimulation (BMS) for osteochondral lesions of the talus (OLTs) has been 150 mm2 in area or 15 mm in diameter. However, recent investigations have failed to detect a significant correlation between the lesion size and clinical outcomes after BMS for OLTs.
Purpose: To systematically review clinical studies reporting both the lesion size and clinical outcomes after BMS for OLTs.
Study design: Systematic review.
Methods: A systematic search of the MEDLINE and EMBASE databases was performed in March 2015 based on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Included studies were evaluated with regard to the level of evidence (LOE), quality of evidence (QOE), lesion size, and clinical outcomes.
Results: Twenty-five studies with 1868 ankles were included; 88% were either LOE 3 or 4, and 96% did not have good QOE. The mean area was 103.8 ± 10.2 mm2 in 20 studies, and the mean diameter was 10.0 ± 3.2 mm in 5 studies. The mean American Orthopaedic Foot and Ankle Society score improved from 62.4 ± 7.9 preoperatively to 83.9 ± 9.2 at a mean 54.1-month follow-up in 14 studies reporting both preoperative and postoperative scores with a mean follow-up of more than 2 years. A significant correlation was found in 3 studies, with a mean lesion area of 107.4 ± 10.4 mm2, while none was reported in 8 studies, with a mean lesion area of 85.3 ± 9.2 mm2. The lesion diameter significantly correlated with clinical outcomes in 2 studies (mean diameter, 10.2 ± 3.2 mm), whereas none was found in 2 studies (mean diameter, 8.8 ± 0.0 mm). However, the reported lesion size measurement method and evaluation method of clinical outcomes widely varied among the studies.
Conclusion: An assessment of the currently available data does suggest that BMS may best be reserved for OLT sizes less than 107.4 mm2 in area and/or 10.2 mm in diameter. Future development in legitimate prognostic size guidelines based on high-quality evidence that correlate with outcomes will surely provide patients with the best potential for successful long-term outcomes.
Keywords: bone marrow stimulation; lesion size; systematic review; talar osteochondral lesion.