Computed tomography–based morphometric analysis of the human occipital condyle for occipital condyle–cervical fusion

Abstract

<jats:sec> <jats:title>Object</jats:title> <jats:p>Occipital condyle screws serve as an alternative fixation point in occipital-cervical fusion. Their placement requires a thorough understanding of the anatomy of the occipital condyles and associated structures. This study is a CT-based morphometric analysis of occipital condyles as related to occipital condyle–cervical fusion.</jats:p></jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>A total of 170 patients were examined with CT scans of the craniocervical junction at a single institution, for a total of 340 occipital condyles, between March 6, 2006, and July 30, 2006. All CT scans were negative for traumatic, degenerative, and neoplastic pathological entities. Condylar anteroposterior (AP) length, transverse width, height, projected screw angle, and projected screw lengths were measured on an EBW Portal 2.5 CT Viewer Workstation (Philips Electronics).</jats:p> <jats:p>The longest axis in the AP orientation of the occipital condyle was accepted as the length. The transverse width was a line perpendicular to the midpoint of the long axis. The height was measured in the coronal projection that had the thickest craniocaudal portion of the condyle. The screw trajectory started 5 mm lateral to the medial edge of the condyle and a line was directed anteromedially in the longest axis. The angle was measured relative to the sagittal midline. The screw length was measured from the outer cortex of the posterior wall to the outer cortex of the anterior wall.</jats:p></jats:sec> <jats:sec> <jats:title>Results</jats:title> <jats:p>The mean ± SD values for occipital condyle measurements were as follows: AP length was 22.38 ± 2.19 mm (range 14.7–27.6 mm); width was 11.18 ± 1.44 mm (range 7.4–19.0 mm); height was 9.92 ± 1.30 mm (range 5.1–14.3 mm); screw angle was 20.30° ± 4.89° (range 8.0°–34.0°); and screw length was 20.30 ± 2.24 mm (range 13.0–27.6 mm).</jats:p></jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>These measurements correlate with previous cadaveric and radiographic studies of the occipital condyle, and emphasize the role of preoperative planning for the feasibility of placement of an occipital condyle screw.</jats:p></jats:sec>

Morphometry of the Occipital Condyle and Basilar Process of Nigerian Skulls

“…Asymmetry in OC dimensions has been reported by Agnihotriet al (2014), [20] and Bazyatet al (2014), [18] in which they stated that the right OC parameters had mean values significantly greater than the left; however, Lang (1995), [33] Cicekcibasiet al (2004), [8] and Tale et al's (2016), [34] reported no significant bilateral differences in the condyle parameters. The hypothesis of difference in data acquisition (radiologic, osteometric and photogrammetric) report by Lang and Hornung (1993), [23] inconsistencies in collection methods (Bozbugaet al, 1999), [15] and genetic endowment (Le et al, 2011;Yu et al, 2015); [13,14] as well as racial/ethnic differences (Lang and Hornung, 1993;Lang, 1995;Bozbugaet al, 1999;Cicekcibasiet al, 2004), [8,15,23] are undoubtedly factors which could impact on the range differences in the value obtained in morphometric studies.…”

“…[5][6][7][8] The occipital condyle (OC) and basilar process (BP) are structures located at the skull base which forms part of the floor of the cranial cavity which by location, differentiates the brain from facial structures and suprahyoid neck (Rautet al, 2012). [9] Name & Address of Corresponding Author Aigbogun (Jr) [8,13,14] with higher values reported for the Asians (Bozbugaet al, 1999; Yu et al, 2015; Salujaet al, 2016), [14][15][16] and lower values for the Caucasians and Australians (Wen et al 1997;Bazyatet al, 2014), [17,18] while for Africans the values fall between values of Asians and Caucasians (Salihet al, 2014; Agnihotriet al, 2014). [19,20] Only a few studies have reported morphometric values for the basilar process (clivus), with dimensions ranging from 24mm to 27mm (Oliviera, 1975; Wescott and Moore-Jansen, 2001), [21,22] and higher values for whites when compared to blacks (Wescott and Moore-Jansen, 2001).…”

“…[19,20] Only a few studies have reported morphometric values for the basilar process (clivus), with dimensions ranging from 24mm to 27mm (Oliviera, 1975; Wescott and Moore-Jansen, 2001), [21,22] and higher values for whites when compared to blacks (Wescott and Moore-Jansen, 2001). [22] Le et al, 2011; [13] Bozbugaet al, 1999; [14,15] Yu et al, 2015 Lang and Hornung, 1993; [23] have suggested that the inconsistencies in the morphometric values of the OC in different population could be attributed to differences in data acquisition, methodology and genetic endowment. Good knowledge of the morphometry of the occipital condyles are very important in surgical interventions, for example, the need to carryout OC recession during various surgical approaches to pathological conditions at the posterior part of the cranial base (Agnihotriet al, 2014; Kalthuret al, 2014; Parvindokhtet al, 2015).…”

Correction of clivoaxial angle deformity in the setting of suboccipital craniectomy: technical note

“…Initially described in 2008 by La Marca et al, 15 then further investigated by Kosnik-Infinger et al 13 and Uribe and colleagues 16,17,25 via radiological and cadaveric analysis, the technique has since been shown to be a viable method to fuse the occiput and cervical spine. Specifically, it has been used in a pediatric setting of craniocervical instability from tumor surgery, craniovertebral anomalies, and prior suboccipital decompression.…”

0.10v feasibility of screw placement in the occipital condyle of chinese patients for occipitocervical arthrodesis: a cadaveric study

“…However, screw and rod fixation methods were less beneficial to tumor patients. Furthermore, a number of studies have recently suggested that OC screw fixation can be a viable and safe alternative for patients who are not eligible for occipital steel plate fixation (6,7,(15)(16)(17)(18). Recent advent and improvements in surgical imaging and reconstruction have made occipitocervical arthrodesis by screw fixation a valuable tool in the surgical armamentarium of medical practitioners around the world.…”