The role of bone in osteochondral talar defects

An osteochondral defect (OCD) of the talus often has a severe effect on the quality of life of young patients. This thesis aims to evaluate several aspects of etiology and treatment of talar OCDs. Part I of the thesis describes the natural history of OCDs and the development of subchondral bone cysts. We concluded after microCT analysis that pressurized fluid plays an important role in the pathofysiology of cyst growth. Part II contains chapters on different surgical treatment options of talar OCDs, the postoperative treatment and rehabilitation after arthroscopic debridement and microfracture. On the basis of this thesis fixation of an OCD with a bony fragment should be considered as the primary treatment. Advantages of this technique are that it restores the natural congruency of the subchondral bone and preserves the hyaline cartilage. When an OCD is not fixable, arthroscopic debridement and microfracture is a good option in defects up to 1.5 cm in diameter. Addition of pulsed electromagnetic fields after arthroscopic debridement and microfracture does neither lead to a higher percentage of patients to resume sports nor to earlier resumption of sports. Finally, a novel metal implant for secondary OCDs was prospectively investigated. Most patients had good clinical outcomes at a mean follow-up of 4.5 years. Eighteen of 20 patients indicating that they would undergo the procedure again.