Midterm Outcomes of Primary Osteochondral Autograft Transfer for Symptomatic Chondral Defects of the Knee

While the deleterious long-term effects of microfracture are well documented, studies examining the long-term clinical outcomes in patients treated with osteochondral autograft transfer (OAT) are scarce.

To assess the mid- and long-term clinical outcomes of primary OAT performed for the treatment of symptomatic articular cartilage lesions of the knee.

Case series; Level of evidence, 4.

The medical records of 63 patients who underwent primary OAT were retrospectively queried from an institutional cartilage registry. Patient-reported outcome measures (PROMs) for patients treated with OAT from the practice of 6 fellowship-trained knee specialists were recorded. Patients with symptomatic articular cartilage lesions of the medial or lateral femoral condyle or trochlea who were treated with OAT were included. All patients had preoperative baseline PROMs; the minimum follow-up was 2 years. Exclusion criteria were previous ipsilateral knee surgical procedures, generalized osteoarthritis, revision cartilage procedures, previous total meniscectomy, and history of inflammatory arthropathy. Clinical outcomes, reoperation rates, and conversion to arthroplasty were analyzed.

The mean patient age was 27.4 ± 12.4 years (range, 11-56 years), and 23/63 (31.7%) were female. The mean follow-up was 5.7 ± 3.2 years (range, 2-16 years). The mean lesion size was 2.3 ± 1.6 cm² (range, 0.6-6.5 cm²), and the mean number of OAT dowels used per case was 2.2 ± 1.3 (range, 1-7). Sixteen patients had a 10-year follow-up. The mean International Knee Documentation Committee (IKDC) score significantly increased from 46.4 ± 15.1 preoperatively to 76.1 ± 19.0 at the 2-year follow-up, 78.0 ± 18.0 at the 5-year follow-up, and 70.4 ± 22.6 at the 10-year follow-up (P < .001). The mean Knee Outcome Survey-Activities of Daily Living score increased from 64.4 ± 16.3 preoperatively to 83.2 ± 12.7 at the 2-year follow-up, 85.1 ± 11.8 at the 5-year follow-up, and 83.8 ± 11.7 at the 10-year follow-up (P < .001). Overall, 69% and 67% of patients treated with OAT surpassed the minimal clinically important difference (MCID), for the IKDC and KOS-ADL scores, respectively, at the 2-year follow-up. Similarly, 60% and 33.3% of patients treated with OAT surpassed the MCID and SCB, respectively, for the IKDC score at the 10-year follow-up. The overall reoperation rate was 28.6% and occurred at a mean of 3.67 ± 6.2 years after the index procedure.

Primary OAT is an effective and durable cartilage restoration procedure for some patients with symptomatic knee cartilage lesions at mid- to long-term follow-up, with a majority of patients demonstrating sustained improvements in clinical outcomes and achieving the MCID. However, a clinically important surgical failure rate exists, with up to one-third of patients needing a revision cartilage restoration procedure and only one-third of patients achieving the SCB for the IKDC score at the 10-year follow-up.