Arthroscopic and histologic findings in Morquio's syndrome.

Mucopolysaccharidosis type IV A/B (Morquio's syndrome) is one of a heterogeneous group of lysosomal storage diseases characterized by accumulation of keratan sulfate in cells of connective tissue. From early childhood, the major orthopaedic manifestations are shortening of the trunk, spondylepiphyseal dysplasia, odontoid hypoplasia, upper cervical instability, lower-limb alignment problems, and degenerative joint disease. Most of the rare published case reports describe those characteristic clinical deformities of the skeleton. Our literature search showed that these striking arthroscopic findings have not been made public to date. We report a typical case of mucopolysaccharidosis type IV. We show and, in particular, correlate the arthroscopic with the histologic findings. In particular, the comparison between arthroscopy and light microscopy showed a remarkable extensive delamination of the chondral layer from subchondral bone of both knee joints. These findings should encourage further research, especially of the osteochondral borderline.