Comparison of clinical outcomes between arthroscopic subchondral drilling and microfracture for osteochondral lesions of the talus

The objectives of this study were to compare the clinical outcomes of the two common bone marrow stimulation techniques such as subchondral drilling and microfracture for symptomatic osteochondral lesions of the talus and to evaluate prognostic factors affecting the outcomes. Ninety patients (90 ankles) who underwent arthroscopic bone marrow stimulation for small- to mid-sized osteochondral lesions of the talus constituted the study cohort. The 90 ankles were divided into two groups: a drilling group (40 ankles) and a microfracture group (50 ankles). Each group was matched for age and gender, and both groups had characteristics similar to those obtained from pre-operative demographic data. The American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score and the ankle activity score (AAS) were used to compare clinical outcomes, during a mean follow-up period of 43 months. The median AOFAS scores were 66.0 points (51-80) in drilling group and 66.5 points (45-81) in microfracture group pre-operatively, and these improved to 89.4 points (77-100) and 90.1 points (69-100) at the final follow-up, respectively. The median VAS scores improved at the final follow-up compared with the pre-operative condition. The median AAS for the drilling group improved from 4.5 (1-6) pre-operatively to 6.0 (1-8) at the final follow-up, while those for the microfracture group improved from 3.0 (2-8) to 6.0 (3-9). No significant differences were observed between the two groups in terms of the AOFAS scores, VAS, and AAS. The arthroscopic subchondral drilling and microfracture techniques that were used to stimulate bone marrow showed similar clinical outcomes. The results of this study suggest that both techniques are effective and reliable in treating small- to mid-sized osteochondral lesions of the talus, regardless of which of the two techniques is used. Level III, retrospective comparative study.