The quantitative anatomy of the ligaments of the middle and lower cervical spine was determined from six human cadaveric specimens using stereo-photogrammetry. For each of the ligaments–anterior longitudinal, posterior longitudinal, capsular, ligamentum flavum, interspinous, and supraspinous–the origins, lengths, and orientations were defined three-dimensionally. The anterior and posterior longitudinal ligaments were ∼7.5 mm wide and 12 mm long at levels C3 through T1, whereas only 3.8 mm wide but 23 mm long and 31 mm long at C1-C2, respectively. The capsular ligaments were fairly constant at all levels, oriented posteriorly at ∼45° to the transverse plane. The ligamentum flavum were relatively constant in width (5 mm), whereas their lengths increased from 5.2 mm at C2-C3 to 8.7 mm at C7-T1. The interspinous ligament was tilted anteriorly 30–40° and was shortest at levels C2-C3 and C3-C4. The supraspinous ligament was more vertically oriented than the interspinous ligament by 15–20°.
Keywords: Quantitative anatomy; Lower cervical spine; Ligaments; Biomechanics