The tenth rib line as a new landmark of the lumbar vertebral level during spinal block

Ultrasound assessment of the anatomic landmarks for spinal anesthesia in elderly patients with hip fracture: A prospective observational study

Tuffier line is a common landmark for spinal anesthesia. The 10th rib line has been suggested as a new landmark to predict the intervertebral levels. We evaluated the accuracy of these 2 anatomic landmarks for identifying the L4-L5 intervertebral space using ultrasonography in elderly patients with hip fracture.Seventy-nine elderly patients scheduled for hip fracture surgery under spinal anesthesia were included. In the lateral decubitus position with the fracture side up, the L4-L5 intervertebral space was identified alternately using Tuffier line, a line drawn between the highest points of both iliac crests, and the 10th rib line. The 10th rib line, an imaginary line that joints the 2 lowest points of the rib cage, passes through the L1-L2 intervertebral space or the body of L2. The L4-L5 intervertebral space was determined by the counting-down method from the 10th rib line. Then, the estimated intervertebral spaces were evaluated using ultrasonography.The L4-L5 intervertebral space was correctly identified in 47 (59%) patients with Tuffier line and 45 (57%) patients with the 10th rib line (P = .87). The estimation ratio related to the intervertebral levels was not different between the 2 landmarks (P = .40). The wrong identifications of intervertebral level with Tuffier line and the 10th rib line was observed in the following order: L3-L4 intervertebral space: 27% vs 24%, L5-S1 intervertebral space: 9% vs 16%, and L2-L3 intervertebral space: 5% vs 3%, respectively.Tuffier line and the 10th rib line may be unreliable to estimate the intervertebral space for spinal anesthesia in elderly patients with hip fracture.

The Sonographic Appearance of Spinal Fluid at Clinically Selected Interspaces in Sitting Versus Lateral Positions

OBJECTIVE

Our objective was to describe the sonographic appearance of fluid at clinically selected interspinous spaces and see if additional interspaces could be identified as suitable and safe targets for needle insertion. We also measured the reproducibility of fluid measurements and assessed for positional differences.

METHODS

A prospective convenience sample of infants younger than 3 months was enrolled in the pediatric emergency department. Excluded were clinically unstable infants or those with spinal dysraphism. Infants were first held in standard lateral lumbar puncture position. Pediatric emergency medicine (PEM) physicians marked infants' backs at the level they would insert a needle using the landmark palpation technique. A PEM sonologist imaged and measured the spinal fluid in 2 orthogonal planes at this marked level in lateral then sitting positions. Fluid measurements were repeated by a second blinded PEM sonologist.

RESULTS

Forty-six infants were enrolled. Ultrasound verified the presence of fluid at the marked level as determined by the landmark palpation technique in 98% of cases. Ultrasound identified additional suitable spaces 1 space higher (82%) and 2 spaces higher (41%). Intraclass correlation coefficient of all measurements was excellent (>0.85), with differences noted for sitting versus lateral position in mean area of fluid 0.34 mm versus 0.31 mm (difference, 0.03; 95% confidence interval [CI], 0.005-0.068), dorsal fluid pocket 0.23 mm versus 0.15 mm (difference, 0.08; 95% CI, 0.031-0.123), and nerve root-to-canal ratio 0.44 versus 0.51 (difference, 0.07; 95% CI, 0.004-0.117).

CONCLUSIONS

Ultrasound can verify the presence of fluid at interspaces determined by the landmark palpation technique and identify additional suitable spaces at higher levels. There were statistically greater fluid measurements in sitting versus lateral positions. These novel fluid measurements were shown to be reliable.

Comparison between two anatomic landmarks using ultrasonography in spinal anesthesia: a randomized controlled trial

BACKGROUND AND OBJECTIVE

Tuffier's line is the most used anatomic landmark in clinical practice. We aimed to compare the accuracy of Tuffier's line with a landmark that joins the two lowest points of the tenth rib on the flanks with the help of ultrasound.

METHODS

A prospective, randomized, controlled, double-blinded trial was performed with 200 patients aged between 18 and 50. Patients taller than 180 cm or shorter than 150 cm, or with body mass index >30 kg/m² were excluded. The first anesthesiologist examined Group T according to Tuffier's line and Group R according to the tenth rib line and marked L_4-5. Only one anesthesiologist evaluated the marked level with ultrasound for accuracy of the anesthesiologist's examination.

RESULTS

There was no difference between groups for demographic and surgical data (p > 0.05). However, we observed a significant difference between the two techniques for success rate (60% in group T vs. 74% in group R) at estimation of correct level (p < 0.05). There was no correlation between success of estimation and patients' demographic data.

CONCLUSION

We conclude that the tenth rib line is better than Tuffier's line for accuracy with palpation. However, it must be confirmed by further studies including more than one examiner for palpation and also include different patient populations.

Radiological Evaluation of the Line Between the Crista Iliaca (Tuffier's line) in Elderly Patients

OBJECTIVE

Tuffier's line is defined as the line connecting the highest points of both iliac crests, which generally passes through either the body of the fourth lumbar vertebra or the intervertebral space between fourth and fifth vertebrae. In this study, we assessed the radiological correlation of the level of Tuffier's line with changes in age and sex.

METHODS

In this study, antero-posterior pelvic X-rays of 590 patients aged 18 and older were retrospectively analyzed. It is revealed that Tuffier's line crosses the vertebral column at one of three levels, which are the L4 vertebral body, L4-L5 vertebral interspace and L5 vertebral body. Patients' sex, age and vertebral level of the Tuffier's line were recorded. Data was analyzed using the chi-square test.

RESULTS

The assessment of the X-rays of 317 female patients showed that Tuffier's Line passes through the L4 vertebral body in 115 (37.8%), through the L4-L5 intervertebral space in 126 (40%) and through the L5 vertebral body in 76 (22.2%) patients. A Tuffier's line passing through the level of the L5 vertebral body was found to be statistically significant in female patients (p=0.00). No significant relevance was found between male gender and the level of Tuffier's line in 273 male patients. It is found that the height of the vertebral levels that Tuffier's line crosses does not correlate with mean age of the groups (p=0.939).

CONCLUSION

It should be considered that Tuffier's line can cross at vertebral levels other than anticipated. The level of Tuffier's line should be precisely determined with supplementary radiological methods, such as AP pelvic X-ray in addition to physical examination, to reduce the complications in association with regional anaeshesia and to achieve sensorial block levels sufficient to sustain a comfortable surgery, particularly in female patients who carry higher cardiac and respiratory risks.

Validity of palpation techniques for the identification of the spinous process L5

For spinal diagnosis and treatment it is important to be able to identify spinal levels by palpation. The objective of this diagnostic study was to examine the validity of four palpation techniques to detect the fifth lumbar vertebra (L5). A physiotherapist examined 66 low back pain patients using first three techniques. Motion palpation (MP), palpation via the posterior superior iliac spines (PSIS technique) and palpation via the iliac crests (CI technique) were deployed in random order. The spinous processes identified using these techniques were marked using an UV marker. The fourth technique was the motion palpation using the previously visible marked landmarks PSIS and CI (MP+). X-rays were taken as a reference standard through replacing the markings by radio-opaque markers. The accuracy of the single techniques ranged from 45% to 61%. There was no significant difference between the individual techniques. If two techniques were in agreement the accuracy ranged from 58% to 78%. If three techniques were in agreement the accuracy ranged from 69% to 83%. This was a significant to highly significant improvement compared to single techniques. If there is agreement between palpation techniques, the accuracy can be significantly improved. This illustrates the need to combine techniques and to relate them to each other. Future studies should investigate combined techniques using marker for further anatomical structures.

Palpatory accuracy of lumbar spinous processes using multiple bony landmarks

OBJECTIVE

Accurate localization of vertebral segments is crucial for many treatment procedures. The objective of this study was to determine accuracy of identification of lumbar spinous process levels by palpation.

METHODS

Three examiners independently identified the spinous processes of L1-L4 on 60 prone volunteers using multiple bony landmarks including the sacral base, L5, Tuffier's line, T12, and the 12th ribs. The spinous processes were marked with radiopaque skin markers. Location of marker placement and presence of anatomical anomalies were determined by posteroanterior lumbar radiographs. Accuracy of marker placement and interobserver reliability were assessed using weighted κ values. Generalized linear mixed models and Cochran-Mantel-Haenszel tests assessed the relationship of accuracy to training level, presence of anatomical anomalies, and participant characteristics.

RESULTS

Examiners identified a spinous process in 91% of vertebral assessments. Correct identification of vertebral level occurred 69% of the time (κ = 0.81; 95% confidence interval, 0.79-0.83). Faculty examiners were significantly more accurate in identifying the correct vertebral level than the resident examiner (67%-78% vs 51%, P ≤ .03). The presence of 12th rib anomalies decreased accuracy for all examiners (P ≤ .05), reducing accuracy from 74% to 55%. Accuracy was higher in male participants than in female participants (P = .01). Obesity significantly decreased accuracy (P = .0003) at L3 (50% vs 73%) and L4 (44% vs 72%).

CONCLUSIONS

Identification of lumbar spinous processes using multiple landmarks was more accurate than previously reported values. However, accuracy was dependent on examiner experience, presence of anatomical anomalies, and participant characteristics.

Reliability of Tuffier's line as an anatomic landmark

STUDY DESIGN

The level of Tuffier's line was assessed on 200 standing and 60 prone lumbar radiographs. Sex, height, weight, and body mass index (BMI) were correlated with the radiograph findings.

OBJECTIVE

To determine whether the level of Tuffier's line is associated with sex, height, weight, or BMI.

SUMMARY OF BACKGROUND DATA

Tuffier's line (intercristal line) is a commonly used landmark for identification of the L4-L5 interspace; however, multiple studies have identified that this landmark is unreliable.

METHODS

The level of Tuffier's line was assessed retrospectively on 200 standing anteroposterior lumbar radiographs and correlated with sex. Prospectively, the level of Tuffier's line was assessed on 60 prone posteroanterior lumbar radiographs and correlated with sex, height, weight, and BMI.

RESULTS

In men, the intercristal line most often intersected the L4 body or inferior endplate. In women, the intercristal line most often intersected the L5 body or superior endplate. Weight and BMI had no correlation with Tuffier's line. Subjects with a Tuffier's line through L4 were taller than those with a Tuffier's line through L5.

CONCLUSION

Tuffier's line demonstrated predictable sex-related differences: men had an intercristal line that most often intersected the L4 body or inferior endplate whereas the women's intercristal line most often intersected the L5 body or superior endplate. However, because the actual level of Tuffier's line may vary from the L4 body to the L5 body, the intercristal line is insufficient to use as the sole landmark for assessing spinal segmental level.

Which spinal levels are identified by palpation of the iliac crests and the posterior superior iliac spines?

The line joining the superior aspect of the iliac crests posteriorly (the intercristal line) is commonly stated to cross the midline at the L4 or L4-5 spinal level on imaging. This study aimed to assess the spinal level identified through palpation of surface anatomy (iliac crests and posterior superior iliac spines) in adults and the level of agreement compared with the intercristal line identified through imaging. The study participants included consecutive adult patients undergoing prone fluoroscopically guided spinal injections for chronic low back pain at the Royal Orthopaedic Hospital, Birmingham, between April and July 2004. Prior to fluoroscopic imaging, each patient's surface anatomy was palpated by two examiners and lines created to form the palpated intercristal line and the posterior superior iliac spine line. Following imaging, the mid-line spinal levels identified by these palpated lines were recorded and the level of agreement (kappa coefficient) with the intercristal line formed by imaging of the iliac crests was assessed. The results showed that although the L4 or L4-5 spinal levels were identified on imaging of the intercristal line in 86.7% of 75 patients (49 female), the intercristal line formed through palpation tended to identify higher levels; the L3 or L3-4 spinal levels in 77.3% of cases and more commonly in females than in males (85.7 vs. 61.5%) and in patients with higher body mass indices. The level of agreement between the two lines was poor (kappa = 0.05). The posterior superior iliac spine line identified the S2 spinous process in 51% and the S1 in 44% of 60 (45 female) patients. The results suggest that formation of the intercristal line by palpation of the iliac crests identifies different spinal levels to those identified by imaging and that both methods should be regarded as different instruments. In the clinical situation, it may be more appropriate to consider that palpation of the intercristal line is a guide for identifying the L3 or L3-4 spinal levels rather than the L4 or L4-5 levels, particularly in females and patients with higher body mass indices.

Comparing the anatomical consistency of the posterior superior iliac spine to the iliac crest as reference landmarks for the lumbopelvic spine: A retrospective radiological study

A palpation reference line coursing between the superior-most aspect of the iliac crests has been reported to cross the L4 spinous process or L4/L5 intervertebral space in approximately 80% of the population. Comparable data have not been defined for the line coursing between the posterior superior iliac spines (PSIS). The purpose of this study was to compare the anatomical consistency of the PSIS to the iliac crest as landmarks used for spinal palpation. One hundred computerized tomographic images were reviewed in a three-dimensional setting. Two horizontal lines were constructed on each image: Line 1 representing the superior-most aspect of the iliac crest and Line 2 representing the inferior margin of the PSIS. The vertical distance between each horizontal line and the inferior edge of its respective spinous process were measured. The PSIS corresponded to the S2 spinous process in 81% of subjects and the iliac crest to the L4 spinous process in 59% of subjects. Distance measures suggest that the PSIS was closer to S2 versus the iliac crest to L4 (t = 6.998; P < 0.01). The PSIS crossed S2 more frequently than the iliac crest crossed L4 (chi(2) = 12.719, P < or = 0.01). The study findings support the relationship between the PSIS, and the spinous process of S2 is more consistent when compared to the iliac crest and the spinous process of L4. The PSIS reference line may be used to find S2 as a reference standard in validity and reliability palpation studies in the lower lumbar spine.

Interexaminer Reliability and Accuracy of Posterior Superior Iliac Spine and Iliac Crest Palpation for Spinal Level Estimations

OBJECTIVE

The purpose of this study was to compare the posterior superior iliac spine (PSIS) and the iliac crest as accurate anatomical landmarks for identifying spinal level.

METHODS

This study was conducted in 2 stages. First, 4 examiners examined 60 patients and blindly identified iliac crest and PSIS levels, and the interexaminer reliability of PSIS and iliac crest palpation were then analyzed. Second, 4 examiners attached a radio opaque marker at presumed PSIS and iliac crest levels in 72 patients, and posteroanterior lumbar radiographs were then taken. Four examiners then confirmed PSIS and iliac crest levels after radiographically identifying the marker levels and checked the spinal level at which the spinous process or interspace was crossed by drawing a horizontal line drawn between radio opaque markers.

RESULTS

The interexaminer reliability of palpation was significantly greater for PSIS level than for the iliac crest (P < .05). Spinal levels of estimated PSISs identified by palpation ranged from the L5-S1 interspace to the S2 spinous process, and the spinal levels of estimated iliac crest ranged from the L2-3 interspace to the L5 spinous process.

CONCLUSIONS

Although PSIS palpation showed statistically higher interexaminer reliability than iliac crest level, clinicians should be cautious when applying this method as a measurement tool because estimated spinal level by palpation can be influenced inadvertently by examiner skill and anatomical variations.

Changes in the iliac crest-lumbar relationship from standing to prone

BACKGROUND CONTEXT

It is known that positioning patients on the Jackson and Andrews operative tables causes changes in lumbar lordosis and pelvic rotation. However, it is unknown if the relationship between the iliac crest and underlying lumbar levels, in particular the L4-L5 interspace, changes from standing to prone on these tables.

PURPOSE

To assess the changes in the relationship between the iliac crests and lumbar spinal levels from standing to prone on two different operative positions using the Jackson and Andrews frames.

STUDY DESIGN/SETTING

Comparative analysis of iliac crest position relative to spinal levels in the preoperative standing position and while positioned on the Jackson and Andrews frames.

PATIENT SAMPLE

48 randomly selected patients who underwent spinal surgery on either the Jackson or Andrews frame.

OUTCOME MEASURES

Imaging.

METHOD

Comparative measurements were made of the preoperative and intraoperative plain lateral lumbar radiographs. The location of the superior border of the iliac crest relative to the L4 lumbar spine level was compared between radiographs.

RESULTS

Preoperatively, the iliac crest aligned with L4/L4-L5 spinal level in 79.2% of the 48 patients compared with 85.5% of intraoperative cases (p=.59). Intraoperative iliac crest level aligned with the L4/L4-L5 level in 80.8% and 90.9% of the patients on the Andrews and Jackson tables respectively (p=.43). Thirty-four patients (70.8%) demonstrated no change in iliac crest alignment between intraoperative and preoperative radiographs. There was a trend for the iliac crest to shift cephalad with operative positioning.

CONCLUSION

Approximately 30% of patients demonstrated changes in the relationship between the iliac crest and lumbar levels between standing and positioning prone. The intraoperative position of the iliac crest aligned more accurately with the L4/L4-L5 spine level on the Jackson and Andrews frame compared with preoperative standing radiographs respectively. Further biomechanical studies should investigate the implication for lumbopelvic fixation.

Spinal anesthesia

PURPOSE OF REVIEW

The aim of this article is to review current practice of spinal anesthesia regarding technique and medication use; review recent applications of spinal anesthesia to subspecialty care in outpatient, cardiac, and obstetrical anesthesia; and update risk assessment associated with spinal anesthesia.

RECENT FINDINGS

Epidural volume extension enhances the spread of local anesthetics using a combined spinal-epidural technique. Chloroprocaine has become the agent of choice at some institutions. The growth in both the number and complexity of ambulatory surgery procedures has redefined the role of spinal anesthesia for outpatients. The 27-gauge Whitacre spinal needle is associated with a lower incidence of post-dural puncture headaches. Retrospective reviews can predict the incidence of rare complications such as neurologic injury and cardiac arrest.

SUMMARY

Innovations in technology, equipment, and needle design improved safety and decreased complication rates from spinal anesthesia. The increased popularity of ambulatory surgical procedures has resulted in more frequent use of spinal anesthesia. Intrathecal narcotic analgesia is used increasingly in fast-tracking cardiac surgical protocols. Modern anesthetic and analgesic techniques include resurgence of older agents (2-chloroprocaine) as well as new agents (levobupivacaine and ropivacaine) that are used in conjunction with adjuvant intrathecal medications (opioids, vasopressors, and alpha-2 adrenergic agonists). Surgical thromboprophylaxis and the increased use of anticoagulants in patients with cardiovascular disease have challenged anesthesiologists to update clinical guidelines to minimize the risk of hemorrhagic complications such as epidural hematoma. The risk/benefit ratio of spinal anesthesia should be individualized. The continued popularity of spinal anesthesia is due to the safety, effectiveness and efficiency of this technique.