Neurovascular structures adjacent to the lumbar intervertebral discs: an anatomical study of their morphometry and relationships

Abstract

<jats:sec> <jats:title>Object</jats:title> <jats:p>Although infrequent, injury to adjacent neurovascular structures during posterior approaches to lumbar intervertebral discs can occur. A detailed anatomical knowledge of relationships may decrease surgical complications.</jats:p></jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>Ten formalin-fixed male cadavers were used for this study. Posterior exposure of the lumbar thecal sac, nerve roots, pedicles, and intervertebral discs was performed. To identify retroperitoneal structures at risk during posterior lumbar discectomy, a transabdominal retroperitoneal approach was performed, and observations were made. The distances between the posterior and anterior edges of the lumbar intervertebral discs were measured, and the relationships between the disc space, pedicle, and nerve root were evaluated.</jats:p></jats:sec> <jats:sec> <jats:title>Results</jats:title> <jats:p>For right and left sides, the mean distance from the inferior pedicle to the disc gradually increased from L1–2 to L4–5 (range 2.7–3.8 mm and 2.9–4.5 mm for right and left side, respectively) and slightly decreased at L5–S1. For right and left sides, the mean distance from the superior pedicle to the disc was more or less the same for all disc spaces (range 9.3–11.6 mm and 8.2–10.5 mm for right and left, respectively). The right and left mean disc-to-root distance for the L3–4 to L5–S1 levels ranged from 8.3 to 22.1 mm and 7.2 to 20.6 mm, respectively. The root origin gradually increased from L-1 to L-5. The right and left nerve root–to-disc angle gradually decreased from L-3 to S-1 (range 105°–110.6° and 99°–108°). Disc heights gradually increased from L1–2 to L5–S1 (range 11.3–17.4 mm). The mean distance between the anterior and posterior borders of the intervertebral discs ranged from 39 to 46 mm for all levels.</jats:p></jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>To avoid neighboring neurovascular structures, instrumentation should not be inserted into the lumbar disc spaces more than 3 cm from their posterior edge. Accurate anatomical knowledge of the relationships of intervertebral discs to nerve roots is needed for spine surgeons.</jats:p></jats:sec>

Distance between Great Vessels and the Lumbar Spine: MRI Study for Anterior Longitudinal Ligament Release Through a Lateral Approach

“…While reproducible data regarding the position of the bifurcation and the confluence of the great vessels were found in the present study, [21][22][23] it is worth considering the bifurcation location in each case. Further, these results may be altered by the presence of transitional bony anatomy.…”

Nerve root to lumbar disc relationships at the intervertebral foramen from a surgical viewpoint: An anatomical study

“…They found that the origin of the root sleeve arose according to the corresponding disc level from rostral to caudal (mean L4 root‐L3‐4 disc distance: 8.3; S1 root‐ L5‐S1 distance: 22.1 mm). Also, in the study of Arslan et al (2011), the angle between the lateral edge of the nerve root and disc level decreased caudally (L4 root‐L3‐4 disc angle: 110.6 degrees; S1 root‐L5‐S1 disc angle: 105 degrees). The results of the current study were consistent with previous data (Suh et al,2005, Arslan et al,2011); but at L5‐S1 levels, due to a wider foraminal diameter in the transverse plane and less foraminal height, the L5 nerve root traveled in a slightly more horizontal direction when compared with the L4 nerve root.…”

“…Suh et al (2005) reported that the nerve‐root angle gradually decreased from L1 to S1. Arslan et al (2011) measured the distance between the origin of the root sleeve and the corresponding disc level in the spinal canal. They found that the origin of the root sleeve arose according to the corresponding disc level from rostral to caudal (mean L4 root‐L3‐4 disc distance: 8.3; S1 root‐ L5‐S1 distance: 22.1 mm).…”

“…The values the authors described above approximately can be used with a linear correction factor in order to rate the laxity of the nerve root when the knees and hips were flexed. Additionally, formalin‐fixed cadavers can alter anatomic relationships due to decreasing the tension within the tissues (Quester et al,1997; Loukas et al,2006; Arslan et al,2011). Suh et al (2005) measured the distance between the origin of the root sleeve and the lower disc in formalin‐preserved and fresh‐frozen cadavers and found an increase in the disc‐root distance in formalin‐fixed compared to fresh‐frozen specimens.…”

Early Outcomes of Minimally Invasive Anterior Longitudinal Ligament Release for Correction of Sagittal Imbalance in Patients with Adult Spinal Deformity

“…Prior to attempting this procedure in vivo, in order to minimize complications, we strongly encourage cadaveric dissection and a review of the literature focusing on the safe zones of the lateral approach [18–21]. In addition to the anatomical nuances regarding the lateral approach previously described, the anatomy of the ALL from the perspective of the lateral transpsoas approach is described by Deukmedjian et al in a recent study [22].…”