Evaluation of the Osteointegrative and Regenerative Capacity of a Scaffold Enriched With Bone Marrow-Derived Cells at the Subchondral Level, Associated With Retrograde Drilling

Osteochondral lesions of the ankle (OsteoChondral Lesions - OCLs) are defects of the subchondral bone and the overlying articular cartilage that commonly affect young and active patients. The main symptoms include chronic ankle pain, recurrent swelling, stiffness, and instability. The ideal treatment for OCLs remains a matter of debate. Various surgical techniques have been proposed, both arthroscopic and open. The choice of treatment depends on several factors, including lesion pathology, patient characteristics, and surgeon preference. In the presence of subchondral cysts or lesions with intact and stable cartilage surfaces, retrograde drilling is among the most commonly used techniques. This is a reparative, extra-articular procedure that reaches the lesion via a retrograde approach, thereby preventing iatrogenic cartilage damage. The surgical technique involves creating multiple channels in the subchondral bone using a Kirschner wire to stimulate the migration of mesenchymal stem cells, promote revascularization of the lesion site, and induce new bone formation. Although retrograde drilling has shown good results over the years, concerns remain regarding the regenerative potential of subchondral bone, particularly in the case of large lesions or cysts. For this reason, various biological adjuncts have been combined with drilling in an attempt to improve treatment efficacy, with inconclusive results. Among the proposed modifications is that of Beck et al., who expanded the talar tunnel to allow for improved debridement, subsequently filling it with bone graft. Another treatment option is subchondroplasty, which has shown promising results; however, few studies are available for the ankle, and significant complications have been reported. Therefore, the management of large subchondral cysts remains controversial. In cases of large OCLs with cartilage damage, regenerative treatments are generally preferred, and several surgical techniques can be performed. Howe