Study design: A morphologic study of manubrium sterni using 3-dimensional computed tomography (3D-CT).
Objective: To investigate the anatomic features of adult manubrium as a source of bone graft and to measure the sizes and available cancellous bone volume of manubrium.
Summary of background data: Manubrium bone graft has been reported as a potential ideal material in anterior cervical fusion surgery, whereas the related applied anatomy is lacking in the literature.
Methods: One hundred twenty adult manubria from 68 male and 52 female patients were scanned and reformatted with 3D-CT. Configurations of manubrium was observed on 3D volume-rendered images. The breadths, height, medullar thickness, and thickness distribution of manubrium were evaluated. A safe area for procurement of graft was proposed and the available cancellous bone volume of manubrium was measured.
Results: Frontal manubrium bears a prominent pentagonal area, which was a bare area without muscle attachments. The breadths, height, and thickness of male manubrium were significantly larger than those of female manubrium. Maximal medullar thickness for male patient was 10.4 ± 1.1 (range, 8.8-12.8) mm, and for female patient it was 9.4 ± 1.4 (range, 6.6-11.9) mm. Minimal medullar thickness for male was 6.8 ± 1.1 (range, 4.9-9.4) mm, and for female it was 5.8 ± 0.9 (range, 4.2-7.4) mm. The thickest region of manubrium located at the level of lower clavicular notches, whereas the thinnest region located at the junction between upper two-thirds and lower third of manubrium. Available volume of cancellous bone was 10.1 ± 2.2 (range, 6.6-15.6) cm(3) in male and 7.7 ± 2.5 (range, 3.6-12) cm(3) in female.
Conclusion: The size of male manubrium is significantly larger than that of female manubrium. Manubrium bone is far more sufficient for most adult anterior cervical fusion surgeries. Safe area for procurement of graft is defined as the upper two-thirds of manubrium, and the optimal site to access medullar cavity is suggested at bare area. However, because considerable variability of manubrium size exists, preoperative evaluation of manubrium is suggested to avoid pitfalls, especially when manubrium graft is intended in a female patient.