The Effect of the Lapidus Arthrodesis on the Medial Longitudinal Arch: A Radiographic Review

We reviewed the medical records and radiographs of 35 patients (3 males, 32 females; mean age 40.8 years) who underwent isolated, modified Lapidus arthrodesis for forefoot pathology in 39 feet. The purpose of the review was to evaluate the structural radiographic changes of the medial longitudinal arch (MLA) following isolated arthrodesis of the first tarsometatarsal joint. Pre- and postoperative standardized measurements of sagittal plane views of the foot were assessed to examine change in the MLA construct. The talo–first metatarsal angle and medial cuneiform height both had statistically significant changes, 2.97 degrees (range, 0–11.5 degrees) and 3.44 mm (range, 0–13 mm) (P < .0001) respectively. Our findings suggest that the Lapidus arthrodesis may influence the medial longitudinal arch. Level of Clinical Evidence: 2