MR-assisted Retrograde Drilling of Osteochondral Lesions of the Talus - A feasibility study -

Introduction: Osteochondrosis dissecans (OD) is a chronic subchondral lesion potentially affecting almost every joint. The etiology still remains unclear. Vascular, traumatic, infectious and genetic causes have been discussed. While stage I (Berndt and Harty classification) can spontaneously heal, the next stages require operative treatment. At stage II it consists of a retrograde drilling of the subchondral lesion perforating the sclerosis zone without damaging the cartilage surface. Some retrograde drilling techniques have been developed using arthroscopic drilling guides, intraoperative fluoroscopy or x-ray navigation. However, the poor visualization under x-ray control can lead to damage of the bone and cartilage. MRI is ideally suited for the evaluation of the osteocartilaginous components of talus lesions and has proven to be useful in planning surgical procedures. In the present study we propose an innovative method using a MR-compatible drilling guide for the minimal-invasive treatment of OD under MR-control.