Arthroscopic treatment of a ganglion of the first metatarsophalangeal joint.

The case of a ganglion that had developed around the first metatarsophalangeal (MTP) joint and in which several other therapeutic approaches were unsuccessful was treated using an arthroscopic assisted procedure. During MTP arthroscopy, we found that the pedicle of the tumor was attached to the interior of the joint, and the lesion was successfully extirpated. Communication with the cyst was found on the medial side of the lateral sesamoid bone, which coincided with the rounded portion of the first MTP joint at the sole, where stress is exerted repeatedly while walking. Thus, the intracystic fluid could not return to the intra-articular space. Instead the cyst gradually extended to the extra-articular tissue, where it was relatively loosely connected. Researchers suspect that a ganglion originally develops through repeated mechanical stress; the lesion is constantly under pressure because of the weight bearing on it. Because of a higher pressure within the MTP joint, the communicating opening acts as a valve.