Ten-Year Retrospective Study of Symptomatic Naviculo-Medial Cuneiform Coalition in 18 Young Adults: Hidden Features Observed on Computed Tomography

CATEGORY: Midfoot/Forefoot INTRODUCTION/PURPOSE: To the best of our knowledge, there are no previous reports comparing the radiographic findings to CT findings for symptomatic naviculo-medial cuneiform (NC) coalition. The purpose of this study was to demonstrate and compare the features of symptomatic naviculo-medial cuneiform coalition between radiography and computed tomography (CT). METHODS: We retrospectively reviewed the radiographic and CT findings of 25 symptomatic naviculo-medial cuneiform coalition cases in 18 patients. The existence of a large pit (depth >3 mm), irregular articular surface, joint space narrowing, dorsal bony spur, subchondral sclerosis, multiple subchondral bony cysts, and intra-articular loose bodies were evaluated on radiograph or CT. The size of the largest subchondral bony cyst was also measured using CT. RESULTS: The proportion of large pit observed on radiograph (52.0%) was significantly different (P = .001) from that on CT (72.0%). Similarly, intra-articular loose bodies were observed more frequently on CT (P = .001). The mean size of the largest subchondral bony cyst on CT was 4.25 mm. CONCLUSION: While evaluating CT in patients with naviculo-medial cuneiform coalition, physicians should focus on detecting a large pit and intra-articular loose bodies since differences in these features were frequently observed between radiograph and CT, with these findings being more evident on CT. We believe that a large subchondral bony cyst could also be related to the symptoms of naviculo-medial cuneiform coalition.