Large osteochondritis dissecans lesion of the knee treated with “snowman” osteochondral allograft transplantation: a case report

Introduction

Symptomatic osteochondritis dissecans (OCD) is a relatively uncommon condition characterized by avascular subchondral bone, resulting in fragmentation and detachment of overlying articular cartilage. Osteochondral allograft transplantation (OCA) offers an effective solution for patients with multifocal, large, unstable, or complex OCD lesions. In certain cases, the “snowman” configuration, involving the use of multiple grafts, may be necessary due to lesion size or shape. This configuration ensures proper press-fit fixation of the grafts while restoring the topography of the articular surface. However, literature on using this technique for large OCD lesions of the lateral femoral condyle remains limited, making it difficult to draw conclusions about surgical outcomes.

Case presentation

Here, we present the case of a 17-year-old patient with a symptomatic, 30 mm × 20 mm OCD lesion of the lateral femoral condyle of the left knee. Initially, conservative treatment and physical therapy were pursued, but an injury during a football game resulted in exacerbation of his condition, necessitating 2 surgeries. The first procedure involved a diagnostic arthroscopy and loose body removal, while the second procedure included an OCA (using 2 plugs in a “snowman” configuration), a lateral meniscus repair, and bone marrow aspirate concentrate to saturate the graft.

Conclusion

The patient experienced favorable outcomes following surgery. Despite the “snowman” technique’s association with higher reoperation and failure rates compared to single or multicompartmental OCA plugs, it remains one of the few viable options for patients with large OCD lesions, enabling full defect restoration and accurate anatomical curvature of the femoral condyle.