Preliminary results of a plantar plate for Lapidus arthrodesis.

The TMT I arthrodesis is an established procedure for the correction of hallux valgus deformity associated with the instability of the TMT-I joint. A risk of transfer metatarsalgia is reported in the literature associated with persistant elevation of MT-I. Detailed information for ideal positioning of the arthrodesis is missing so far. Clinical, radiological and padobarografical results and their correlations were analyzed with special consideration of the elevation position of the MT-I in a TMT-I arthrodesis using the plantar plate osteosynthesis. Postoperative changes in plantar pressure and force distribution occured after TMT-I arthrodesis. A postoperative increase of the load under the medial forefoot and the dependence on the positioning of MT-I in the sagittal plane has been shown. The authors suggest, that increased load of the medial forefoot and constant pressures and forces under the central forefoot may lead to a relative relief of the area, which might explain the postoperative reduction of metatarsalgia.