Surgical treatment for medium-sized cystic osteochondral lesions of the talus: Autologous osteoperiosteal transplantation provides better clinical outcomes than bone marrow stimulation when cysts are deeper than 6 mm

Purpose: To compare clinical outcomes of autologous osteoperiosteal transplantation versus bone marrow stimulation (BMS) for medium-sized (100-150 mm(2)) cystic osteochondral lesions of the talus (OLTs) and assess the correlation between patient demographics and outcomes. It was hypothesised that autologous osteoperiosteal transplantation would provide better clinical outcomes than BMS for medium-sized cystic OLTs. Methods: Patients who underwent autologous osteoperiosteal transplantation or BMS for medium-sized cystic OLTs between 2014 and 2019 were retrospectively evaluated. According to their characteristics, a 1:1 propensity-score matching was performed and 33 pairs of patients were matched. The visual analogue scale, American Orthopaedic Foot and Ankle Society (AOFAS) score, Foot Ankle Outcome Score (FAOS) and Ankle Activity Score were collected preoperatively and at the last follow-up. In addition, a general linear model analysis was performed between patient demographics and clinical outcomes in two groups separately to detect potential risk factors. Results: Finally, 28 patients in the grafted group and 27 patients in the BMS group completed the follow-up and were enrolled with a mean follow-up period of 63.5 +/- 13.9 months. Both groups showed significant improvement in all patient-reported outcomes (p < 0.01). At the final follow-up, no significant differences between groups were found in all postoperative scores except FAOS Pain (p = 0.02). Correlation analysis showed a moderate correlation between cyst depth and the postoperative AOFAS score in the BMS group (r = -0.48, p = 0.01). Based on the regression line, the patients in the BMS group with a cyst deeper than 6 mm showed a lower AOFAS score than the mean score (88.7 +/- 9.5) of the grafted group. Conclusion: Autologous osteoperiosteal transplantation and BMS are both safe and effective for medium-sized cystic OLTs. However, autologous osteoperiosteal transplantation is expected to provide better clinical outcomes than BMS when the cysts are deeper than 6 mm.