Is a 2 cm 2 Lower Lesion-Size Threshold Justified for Bone Marrow Aspirate Concentrate Treatment of Osteochondral Lesions of the Talus? Reassessing Lesion-Size and Age Criteria for Non-Covered Use in Korea

In Korea, an autologous bone marrow-derived cell concentrate for cartilage defects is a non-covered technology whose safety and efficacy were evaluated only for a lesion-size range of 2~10 cm 2 , without a joint-specific threshold.Despite this, osteochondral lesions of the talus (OLTs) are commonly smaller than 2 cm 2 .Therefore, this lower boundary may restrict access to bone marrow aspirate concentrate (BMAC) and impede domestic evidence generation because OLTs are commonly smaller than 2 cm 2 .The original 2011 assessment was based on four low-level reports (one retrospective cohort and three case series), and neither the initial public notice nor the 2018 reassessment compared outcomes below 2 cm 2 versus above 2 cm 2 or tested a size-by-treatment interaction.Therefore, this review examined whether 2 cm 2 is a valid lower threshold for the effect of BMAC in OLTs.BMAC has been used and has shown clinical improvement even in lesions below 2 cm 2 (mean 103 mm 2 in Hannon et al.; mostly <1.5 cm 2 in Murphy et al.; 87 lesions <100 mm 2 in Shimozono et al.).Despite this, most evidence was nonrandomized, and the independent effects of BMAC could not be isolated because bone marrow stimulation, scaffolds, bone grafting, and fibrin were combined.Therefore, current evidence supports the feasibility and a benefit signal below 2 cm 2 but does not establish superiority or first-line use.The lesion-size cutoffs in OLTs were originally derived as prognostic factors for bone marrow stimulation rather than as efficacy thresholds for other procedures, and a gray zone exists between 1.5 cm 2 , at 거골 골연골병변의 BMAC 치료에서 2 cm 2 하한선은 타당한가?병변 크기와 연령 기준을 포함한 국내 비급여 적용 범위의 재평가