Computed tomography measurements of the lesser metatarsal heads: Anatomic considerations for surgeons performing distal metatarsal osteotomies

Background: The purpose of the current study was to provide a standardized, anatomical description of the lesser metatarsals to assist surgeons when planning distal metatarsal surgery and fixation. Methods: Eighty CT scans were included for assessment, based on a priori power analysis. Patient age was a mean 52.7 +/- 16.6 years (24-83). Metatarsals two through five were assessed in all patients. Three independent observers completed measurements for all metatarsals. Three measurements were made on all metatarsals, including a vertical height and metatarsal head and neck measurements. Statistical analysis was performed (alpha value 0.05). Inter-observer reliability was assessed for all measurements and intra-class correlation (ICC) reported. Results: A sequential decrease in metatarsal measurements was noted from the second to the fifth metatarsal. A mean vertical height measurement of 16.1 +/- 1.4 mm(range, 13.4-19.4) was recorded for the second metatarsal, decreasing 13.0 +/- 1.1 mm (range, 10.3-16.1) for fifth. There were no significant differences in metatarsal measurements based on gender in our study. Similar patient and metatarsal variability was seen head and neck measurements. Intraclass correlation coefficients (ICC) for metatarsal measurements were greater than 0.9 [95% CI; 0.936-0.991] correlation, denoting an 'excellent' interobserver reliability. Conclusion: This study provides a baseline anatomical description of the distal metatarsals. These findings, including the variation found between patients and between metatarsal two through five, are relevant to surgeons planning and performing distal metatarsal osteotomies. (C) 2016 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.