Arthroscopic Bone Marrow Stimulation for Non-primary Osteochondral Lesions of the Talus Yields Limited Improvements in Patient-Reported Outcomes Compared to Primary Lesions: A Prospective 2-Year Follow-up Study.

Abstract

Our aim in this study was to prospectively assess the patient-reported clinical outcomes of arthroscopic bone marrow stimulation (BMS) for non-primary osteochondral lesions of the talus (OLT) and to compare these with primary cases at 2-year follow-up. The secondary aims were to assess the association of baseline factors with outcomes and the occurrence of adverse events. Patients who underwent arthroscopic BMS were prospectively included and assessed up to 2-year follow-up and were grouped according to non-primary (ie, failed previous OLT surgery) or primary BMS. Patient-reported outcomes were collected at baseline and 2-year follow-up and included the numeric rating scale (NRS) for pain and the Foot and Ankle Outcome Score (FAOS) questionnaires. The primary outcome was the improvement in NRS pain during walking, with a minimal clinically important difference (MCID) of 2.0. Adverse events concerned reoperations and complications during the study period. Forty-four patients were included: 25 in the primary group and 19 in the non-primary group. Both groups showed a statistically significant improvement in pain and functional outcomes from preoperatively to 2-year follow-up. The improvement in the primary outcome was significantly higher in the primary group (median 3 [IQR: 1-5] out of 10) compared to the non-primary group (median 1 [IQR: 1-3] out of 10), <i>P</i> = .01. Moreover, 68% (95% CI 46%-85%) reached the MCID compared with 32% (95% CI 13%-57%) in the non-primary group, which was statistically significant (<i>P</i> = .03). Baseline variables showed no consistent association with the primary outcome, except for a moderate correlation with age and lower improvements for patients who received concomitant surgery in the primary group. None of the changes in the FAOS sub-scales showed a statistically significant difference between the two groups. Two revision procedures (non-primary group: 11% [95% CI 1%-33%] vs 0% primary group, <i>P</i> = .2) occurred in the non-primary group. During the study period, 1 case (non-primary group: 5% [1%-26%] vs primary group: 0%, <i>P</i> = .4) had a complication. The most important finding of this prospective study is that arthroscopic BMS for non-primary OLT yields a significant improvement in patient-reported outcomes compared with baseline, but an inferior improvement compared with primary OLT at 2-year follow-up. On average, approximately two-thirds of BMS-treated primary OLTs reached the MCID compared with one-third in the non-primary group. Level II, prospective comparative cohort study.