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Response to "Letter Regarding: Long-term Outcomes of Microfracture for Treatment of Osteochondral Lesions of the Talus".

Dear Editor We thank Dr. ter Laak Bolk et al for their letter regarding our study titled “Long-term Outcomes of Microfracture for Treatment of Osteochondral Lesions of the Talus.”1 We agree with their first concern that only 55% of patients were available for follow-up 10 years after their surgery, and acknowledge this as a weakness within the article. Although this inherently creates bias, this is difficult to avoid in such long-term follow-up studies on a young mobile population. We did, however, analyze all available results for outcome, including size and morphology. Lesion size ranged from a surface area 20 to 270 mm2 with no correlation with any outcome measure analyses (see Table 7 in the article). In fact, only age at the time of surgery ≥50 years was shown to be a negative predictor of outcome. None of the patients in this study were augmented with additional orthobiologics. The purpose of the study was to demonstrate outcome of arthroscopic microfracture without these expensive orthobiologics, where 10 years after their surgery, 93.3% of patients had not required any additional surgery, more than 85% were able to participate in the sports of their choice and were satisfied with their surgical outcomes. We do thank you for referencing some of the newer European literature. Two of these studies were published in 2021 after ours was submitted and could not be referenced. Rikken et al, in his meta-analysis with pooled follow-up of 13 years, demonstrated similar results to ours, with 93.1% of patients not requiring additional surgery and 78% being able to participate in the sports of their choice. They did report 28% radiographic progression in arthritis, but with no correlation to outcome or proof that this actually leads to symptomatic arthritis in the future.3 Lambers et al published on 6.3 years’ average follow-up, with 90% of patients participating in sports. This study does show deteriorating Foot and Ankle Outcome Scores (although pain that remained very low) between 1 year and 6 years following surgery but no correlation with sports participation.2 These less favorable results may be due to many factors, including surgical technique, post operative protocols, etc. With regard to outcome measures uses, the Foot and Ankle Outcome Measure (FAAM) has been validated for a wide range of foot and ankle pathologies and has a complete subsection analyzing sports participation. We feel that this is a very acceptable patient-reported outcome system for osteochondral lesions of the ankle as there is currently no validated scoring system specifically for osteochondral lesions. We do thank you for your comments about our reported pain scores, and appreciate the opportunity to clarify our reported numbers. Patients were specifically asked what their pain was during sporting activity—marked on a 100-mm line, and measured between 0 and 100 points. The average pain with this weightbearing activity was 14/100 in the ankle. We thank the letter writers again for their thought-provoking comments and applaud them for their own published work on this topic.2,3 We encourage further long-term outcome studies on this topic to further our understanding of the management of osteochondral lesions of the talus and to answer the questions of the potential benefit of orthobiologics. Sincerely