Limits...
Anatomic variations of cervical and high thoracic ligamentum flavum.

Yoon SP, Kim HJ, Choi YS - Korean J Pain (2014)

Bottom Line: The incidence decreased below this level and was the lowest at T4-T5 (8%).Therefore, the ligamentum flavum is not always reliable as a perceptible barrier to identify the epidural space at these vertebral levels.Additionally, it may be more useful to insert the needle into the cephalic portion of the intervertebral space than in the caudal portion.

View Article: PubMed Central - PubMed

Affiliation: Department of Anatomy, Jeju National University, School of Medicine, Jeju, Korea.

ABSTRACT

Background: Epidural blocks are widely used for the management of acute and chronic pain. The technique of loss of resistance is frequently adopted to determine the epidural space. A discontinuity of the ligamentum flavum may increase the risk of failure to identify the epidural space. The purpose of this study was to investigate the anatomic variations of the cervical and high thoracic ligamentum flavum in embalmed cadavers.

Methods: Vertebral column specimens of 15 human cadavers were obtained. After vertebral arches were detached from pedicles, the dural sac and epidural connective tissue were removed. The ligamentum flavum from C3 to T6 was directly examined anteriorly.

Results: The incidence of midline gaps in the ligamentum flavum was 87%-100% between C3 and T2. The incidence decreased below this level and was the lowest at T4-T5 (8%). Among the levels with a gap, the location of a gap in the caudal third of the ligamentum flavum was more frequent than in the middle or cephalic portion of the ligamentum flavum.

Conclusions: The cervical and high thoracic ligamentum flavum frequently has midline intervals with various features, especially in the caudal portion of the intervertebral space. Therefore, the ligamentum flavum is not always reliable as a perceptible barrier to identify the epidural space at these vertebral levels. Additionally, it may be more useful to insert the needle into the cephalic portion of the intervertebral space than in the caudal portion.

No MeSH data available.


Related in: MedlinePlus

Classification of the midline gap in the ligamentum flavum. Type A is no gap throughout the entire length of LF. Type B is a gap in a portion of LF (B1: gap in the caudal third of LF, B2: gap in the middle third of LF, B3: gap in the cephalic third of LF). Type C is a midline gap throughout LF (C1: midline gap throughout the entire height of LF, C2: midline gap wider in the caudal third of LF, C3: midline gap with a fusion in the middle of the gap).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4196496&req=5

Figure 2: Classification of the midline gap in the ligamentum flavum. Type A is no gap throughout the entire length of LF. Type B is a gap in a portion of LF (B1: gap in the caudal third of LF, B2: gap in the middle third of LF, B3: gap in the cephalic third of LF). Type C is a midline gap throughout LF (C1: midline gap throughout the entire height of LF, C2: midline gap wider in the caudal third of LF, C3: midline gap with a fusion in the middle of the gap).

Mentions: Specimens of cervical and high thoracic vertebral column were obtained from human adult cadavers preserved in a mixture of formaldehyde and carbol (Fig. 1). After vertebral arches were detached from the pedicles, the dural sac and epidural connective tissue were removed. The LF from C3 to T6 was directly examined from the anterior. The gaps of LF in the midline were classified as depicted in Fig. 2 and described subsequently. Type A was no gap throughout the entire length of LF. Type B was a gap in a portion of LF (B1, gap in the caudal third of LF; B2, gap in the middle third of LF; B3, gap in the cephalic third of LF). Type C was a midline gap throughout LF (C1, midline gap throughout the entire height of LF; C2, midline gap wider in the caudal third of LF; C3, midline gap with a fusion in the middle of the gap).


Anatomic variations of cervical and high thoracic ligamentum flavum.

Yoon SP, Kim HJ, Choi YS - Korean J Pain (2014)

Classification of the midline gap in the ligamentum flavum. Type A is no gap throughout the entire length of LF. Type B is a gap in a portion of LF (B1: gap in the caudal third of LF, B2: gap in the middle third of LF, B3: gap in the cephalic third of LF). Type C is a midline gap throughout LF (C1: midline gap throughout the entire height of LF, C2: midline gap wider in the caudal third of LF, C3: midline gap with a fusion in the middle of the gap).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4196496&req=5

Figure 2: Classification of the midline gap in the ligamentum flavum. Type A is no gap throughout the entire length of LF. Type B is a gap in a portion of LF (B1: gap in the caudal third of LF, B2: gap in the middle third of LF, B3: gap in the cephalic third of LF). Type C is a midline gap throughout LF (C1: midline gap throughout the entire height of LF, C2: midline gap wider in the caudal third of LF, C3: midline gap with a fusion in the middle of the gap).
Mentions: Specimens of cervical and high thoracic vertebral column were obtained from human adult cadavers preserved in a mixture of formaldehyde and carbol (Fig. 1). After vertebral arches were detached from the pedicles, the dural sac and epidural connective tissue were removed. The LF from C3 to T6 was directly examined from the anterior. The gaps of LF in the midline were classified as depicted in Fig. 2 and described subsequently. Type A was no gap throughout the entire length of LF. Type B was a gap in a portion of LF (B1, gap in the caudal third of LF; B2, gap in the middle third of LF; B3, gap in the cephalic third of LF). Type C was a midline gap throughout LF (C1, midline gap throughout the entire height of LF; C2, midline gap wider in the caudal third of LF; C3, midline gap with a fusion in the middle of the gap).

Bottom Line: The incidence decreased below this level and was the lowest at T4-T5 (8%).Therefore, the ligamentum flavum is not always reliable as a perceptible barrier to identify the epidural space at these vertebral levels.Additionally, it may be more useful to insert the needle into the cephalic portion of the intervertebral space than in the caudal portion.

View Article: PubMed Central - PubMed

Affiliation: Department of Anatomy, Jeju National University, School of Medicine, Jeju, Korea.

ABSTRACT

Background: Epidural blocks are widely used for the management of acute and chronic pain. The technique of loss of resistance is frequently adopted to determine the epidural space. A discontinuity of the ligamentum flavum may increase the risk of failure to identify the epidural space. The purpose of this study was to investigate the anatomic variations of the cervical and high thoracic ligamentum flavum in embalmed cadavers.

Methods: Vertebral column specimens of 15 human cadavers were obtained. After vertebral arches were detached from pedicles, the dural sac and epidural connective tissue were removed. The ligamentum flavum from C3 to T6 was directly examined anteriorly.

Results: The incidence of midline gaps in the ligamentum flavum was 87%-100% between C3 and T2. The incidence decreased below this level and was the lowest at T4-T5 (8%). Among the levels with a gap, the location of a gap in the caudal third of the ligamentum flavum was more frequent than in the middle or cephalic portion of the ligamentum flavum.

Conclusions: The cervical and high thoracic ligamentum flavum frequently has midline intervals with various features, especially in the caudal portion of the intervertebral space. Therefore, the ligamentum flavum is not always reliable as a perceptible barrier to identify the epidural space at these vertebral levels. Additionally, it may be more useful to insert the needle into the cephalic portion of the intervertebral space than in the caudal portion.

No MeSH data available.


Related in: MedlinePlus