An Anatomical and Morphometric Study of the Coccyx Using Three‐Dimensional Reconstruction

Abstract

To provide anatomical and morphological data regarding the coccyx using three-dimensional images, with a view to aiding the diagnosis of idiopathic coccydynia, one hundred and thirty-six normal adult pelvises were investigated. Three-dimensional models of the pelvis were reconstructed using software from computed tomography images of whole specimens. The following six coccyx parameters were measured: (1) width, (2) straight length, (3) thickness, (4) sacrococcygeal angle, (5) intercoccygeal angle, and (6) angle of lateral deviation of the coccyx. The presence of fusion between the sacral and coccygeal cornua, and between the sacrum and the transverse process of the coccyx was also investigated, and lateral deviations of the coccyx were classified and analyzed. Most of the measured coccyx parameters were larger in males than in females, with the exception of the sacrococcygeal and intercoccygeal angles. Unilateral or bilateral fusion of the sacral cornu and the coccygeal cornu was not a rare finding. With respect to the sacrum and the transverse process of coccyx, the separated type was more common than the fused type. The incidence and angle of lateral deviation of the coccyx varied widely between individuals. The present detailed description of the gross anatomy of the coccyx obtained using three-dimensional modeling will help toward understanding the mechanism underlying the development of idiopathic coccydynia. Fusion of the sacrum and coccyx or lateral deviation of the coccyx may cause coccydynia by compressing the coccygeal nerves. Anat Rec, 299:307-312, 2016. V C 2015 Wiley Periodicals, Inc.

Coccygeal Morphology on Multislice Computed Tomography in a Tertiary Hospital in India

“…Sacrococcygeal fusion was found in 34% of the sample [ 14 ]. Lee et al [ 15 ], in their morphometric study of the coccyx using three-dimensional reconstruction in 136 normal adult pelvises, found that most of the measured coccyx parameters were larger in males than in females, with the exception of sacrococcygeal and intercoccygeal curvature angles.…”

Koksidinialı Hastalarda koksiksin morfometrik değerlendirilmesi ve sınıflandırması

“…This value was evaluated as 38.5 mm for males and 34.5 mm for females, and males were longer than females. Lee et al [7] found average coccyx length in males to be 37.9 mm and 34.4 mm in females. Indiran et al [18] found average coccyx length as 33.8 mm in males and 31.5 mm in females.…”

Concurrent lumbosacral and sacrococcygeal fusion: a rare aetiology of low back pain and coccygodynia?

“…In case of a synostosis between sacrum and coccyx, the fusion may include the sacral and coccygeal cornua or the coccygeal transverse processes and the sacrum, and it can be unilateral or bilateral in both cases (2). Coccygeal sacralization is defined as unilateral or bilateral fusion of the transverse processes of the first coccygeal segment to the inferolateral angle of the sacrum, Accurate knowledge of the anatomy of the sacral region may be crucial in some cases for the accuracy of the diagnosis or an operation in the area.…”

“…Both the lumbosacral joint and the sacrococcygeal symphysis are related to a great amount of variations, due to a possible synostosis of the bones from which the articulation is constituted (7,3,2,5). The authors report a rare variation in which there is a concurrent synostosis of the sacral bone with the last lumbar vertebra (L5) and the coccyx.…”

“…The significance of this case is dual: the two synostoses and the existence of six sacral foramina. Coccygodynia and symptoms due to neurological or biomechanical malfunction could possibly be explained by the presence of this anatomical variation (2).…”