The use of biodegradables in the treatment of osteochondritis dissecans of the knee: fiction or future?

The use of biodegradable fixation devices in the operative treatment of osteochondritis dissecans of the knee could avoid a second operation for removal of the hardware, but what are the disadvantages? Seven osteochondritis dissecans lesions, non-displaced in four adult knees and in one adolescent knee and displaced in two knees of adolescents, were treated by drilling and stabilisation with biodegradable pins, resulting in primary consolidation in the five non-displaced lesions and failure in the two detached lesions. However, two detached fragments in adults, primarily fixed with one metallic compression screw and three biodegradable pins both consolidated. In another adult patient, the fixation with two compression screws failed. A study of the available literature and the results of our limited experience seem to indicate that the primary operative treatment of choice of a non-detached osteochondritis dissecans lesion is drilling and fixation with biodegradable pins. However, if this regimen fails or in patients with a detached lesion, one metallic screw and a few additional biodegradable pins appear to constitute the best method of fixation. The use of biodegradable screws is still hazardous, because of the long degradation time and subsequent risk of erosion of the opposite cartilage and tissue reaction. Other resurfacing options are available for failures or fragmented or non-vital lesions.