Anatomy of the human thoracolumbar Rami dorsales nervi spinalis

Sacroiliac innervation

PURPOSE

To investigate the innervation pattern of the sacroiliac region, especially with regard to the sacroiliac joint (SIJ). Dorsal SIJ innervation was analyzed and described. Our main hypothesis was that nerves reach the SIJ dorsally, passing ligamental compartments, as this would explain dorsal SIJ pain.

METHODS

To examine sacroiliac innervation, we followed the nerves in over 50 specimens over several years. Plastinated slices were evaluated, nerves in the region were stained histologically, and the data were summarized as 3D models.

RESULTS

The Rami communicans and posterior branches of the spinal nerves and their branches that form a dorsal sacral plexus and communicating branches, together with corresponding vessels, were observed to form neurovascular bundles embedded by tiny fatty connectives in gaps and tunnels. Branches of L5-S1 pass the inner sacroiliac ligaments (the interosseous sacroiliac ligament and axial interosseous ligament). The outer sacroiliac ligaments (posterior sacroiliac ligaments, long posterior sacroiliac ligament, sacrotuberal ligament, thoracolumbar fascia) are passed by the S1-S4 branches. However, although the paths of these nerves are in the direction of the SIJ, they do not reach it. It is possible that impingement of the neurovascular bundles may result in pain. Moreover, the gaps and tunnels connect to the open dorsal SIJ.

CONCLUSION

Our findings suggest that Bogduk's term "sacroiliac pain" correlates to "sacroiliac innervation", which consists of "inner-" and "outer sacroiliac ligament innervation", and to ventral "SIJ pain". The watery gaps and tunnels observed could play a significant role in innervation and thus in the origins of SIJ pain.

LEVEL OF EVIDENCE

Individual cross-sectional studies with consistently applied reference standard and blinding.

A Study on the Anatomical Relationship of the Lumbar Extrapedicular Puncture Approach with the Spinal Nerve and its Branches

The anatomical relationship of the extrapedicular approach with the spinal nerve and its branches was researched in cadavers. Three types of extrapedicular paths were simulated: puncture inside the medial branch (MB), puncture outside the MB, and puncture outside the lateral branch (LB). At L1-L3, puncture outside the LB could avoid damage to these nerves.

The Analgesic Efficacy of Erector Spinae Plane Blocks in Patients Undergoing Posterior Lumbar Spinal Surgery for Lumbar Fracture

OBJECTIVE

To investigate the postoperative analgesic efficacy of ultrasound-guided lumbar erector spinae plane (ESP) blocks in patients undergoing posterior lumbar spinal surgery for lumbar spinal fractures.

METHODS

A total of 80 patients who were scheduled for posterior internal fixation for lumbar spinal fractures were divided into a patient-controlled analgesia (PCA) group or a combined ESP-PCA group. Numeric rating scale at rest and during movement, postoperative sufentanil consumption, and accumulative and effective bolus presses of PCA were recorded at 6, 12, 24, and 48 hours postoperatively. Numeric rating scale at rest and during movement was the primary outcome. Incidence of postoperative nausea and vomiting during the first 24-48 hours, pruritus and chronic postoperative pain, and dose of pethidine for rescue analgesia were also recorded.

RESULTS

Numeric rating scale at rest and during movement at 6, 12, and 24 hours was lower in the ESP-PCA group (P < 0.001, P < 0.001, P = 0.0016 at rest; all P < 0.001 during movement). Lumbar ESP blocks diminished accumulative bolus presses and effective bolus presses of PCA at 6, 12, 24, and 48 hours postoperatively. Besides, patients in the ESP-PCA group had fewer demands for sufentanil and pethidine. The incidence of postoperative nausea and vomiting in the ESP-PCA group was lower than that in PCA group.

CONCLUSIONS

PCA combined with lumbar ESP blocks provided superior postoperative analgesia for patients with lumbar spinal fractures treated with posterior internal fixation. Lumbar ESP blocks decreased postoperative opioid consumption and incidence of postoperative nausea and vomiting, thereby enhancing postoperative recovery.

Quantitative analysis of paraspinal muscle atrophy after oblique lateral interbody fusion alone vs. combined with percutaneous pedicle screw fixation in patients with spondylolisthesis

BACKGROUND

There is no available literature for comparison on muscle atrophy between the "stand-alone" oblique lateral interbody fusion (OLIF) and regular OLIF (i.e., combined with percutaneous pedicle screws fixation (PPSF) in patients with spondylolisthesis). This study aimed to identify changes in back muscle atrophy between the two surgeries.

METHODS

This was a retrospective cohort study of patients who underwent OLIF or OLIF+PPSF at Beijing Jishuitan Hospital and Shanghai ChangZheng Hospital between 07/2014 and 10/2017. Computed tomography (CT) was used to measure functional cross-sectional area (FCSA) and fat infiltration percentage (FIP) of the multifidus and erector spinae before and 24 months after surgery.

RESULT

There were no differences in FCSA and FIP between OLIF (n = 32) and OLIF+PPSF (n = 41) groups before surgery. In the OLIF group, the multifidus and erector spinae FCSA and FIP did not change at 24 months (FCSA: multifidus: from 8.59 ± 1.76 to 9.39 ± 1.74 cm², P = 0.072; erector spinae: from 13.32 ± 1.59 to 13.55 ± 1.31 cm², P = 0.533) (FIP: multifidus: from 15.91 ± 5.30% to 14.38 ± 3.21%, P = 0.721; erector spinae: from 11.63 ± 3.05% to 11.22 ± 3.12%, P = 0.578). In the OLIF+PPSF group, the multifidus and erector spinae FCSA decreased (multifidus: from 7.72 ± 2.69 to 5.67 ± 1.71 cm², P < 0.001; erector spinae: from 12.60 ± 2.04 to 10.15 ± 1.82 cm², P < 0.001), while the FIP increased (multifidus: from 16.13 ± 7.01% to 49.38 ± 20.54%, P < 0.001; erector spinae: from 11.93 ± 3.22% to 22.60 ± 4.99%, P < 0.001). The differences of FCSA and FIP between the two groups at 24 months were significant (all P < 0.001). The patients in the standalone OLIF group had better VAS back pain, and JOA scores than the patients in the OLIF combined group (all P < 0.05) at 1 week and 3 months after surgery. There were two cases (4.9%) of adjacent segment degeneration in the OLIF combined group, while there was no case in the OLIF alone group.

CONCLUSIONS

Standalone OLIF had better clinical outcomes at 1 week and 3 months than OLIF+PPSF in patients with spondylolisthesis. OLIF may not result in paraspinal muscle atrophy at 24 months after surgery.

Comparison of Effects of Hemostatic Gelatin Sponge Impregnated with Ropivacaine versus Normal Saline Applied on the Transverse Process of the Operated Vertebrae on Postoperative Pain in Patients Undergoing Spinal Instrumentation Surgery: A Randomized Clinical Trial

BACKGROUND

Protocols for effective postoperative pain control in patients undergoing spinal surgery are not standardized. In our study, we compared the effects of hemostatic absorbable gelatin sponge impregnated with ropivacaine versus normal saline when applied to the transverse process of the operated vertebrae on the postoperative pain following instrumentation spine surgery.

METHODS

A prospective double-blind randomized study was conducted on 30 patients undergoing spine surgery. At the end of surgery, the hemostatic gelatin sponge was applied by the surgeon on the transverse process of the operated vertebra containing either ropivacaine 0.5% or normal saline NaCl 0.9. Pain was assessed using the visual analog scale (VAS) every 4 hours for 48 hours postoperatively in the 2 groups (ropivacaine vs. normal saline). The total amount of postoperative opioid use was also recorded.

RESULTS

The VAS score was significantly lower in patients receiving hemostatic gelatin sponge impregnated with local anesthetics as compared with patients receiving gelatin sponge impregnated with normal saline 48 hours postoperatively; the mean total dose of meperidine given in the first 48 hours postoperatively was significantly lower (53.5 ± 51.0 mg) in patients receiving gelatin sponge impregnated with local anesthetics as compared with patients receiving hemostatic gelatin sponge impregnated with normal saline (140.5 ± 102 mg).

CONCLUSIONS

Use of intraoperative hemostatic gelatin sponge impregnated with ropivacaine applied on the transverse process of the operated vertebrae intraoperatively resulted in decreasing the postoperative pain in patients undergoing lumbar instrumentation surgery as manifested by the decrease in the VAS score and the total dose of opioids.

Comparative Study of 2 Skin Incisions for Microscopic Lumbar Discectomy

OBJECTIVE

Microscopic lumbar discectomy is a common minimally invasive surgery. A transverse skin incision has sound theoretical cosmetic advantages compared with the classic vertical incision. We compared transverse and vertical skin incisions for microscopic discectomy regarding cosmetic outcome, postoperative pain, and the provided surgical cutaneous inlet.

METHODS

This prospective study enrolled 86 patients who were randomly assigned to a vertical incision group or a transverse incision group. The maximum surgical cutaneous inlet provided was measured in 2 diameters. Pain was recorded on postoperative days 1, 3, and 7 using a numeric patient rating scale from 0 to 10 with 0 indicating no pain. The cosmetic appearance of the wound was evaluated by a plastic surgeon and by the patients as excellent, very good, good, fair, and poor.

RESULTS

Compared with vertical incisions, transverse incisions provide similar surgical cutaneous inlets, cause higher pain scores on postoperative days 1 and 3 but a similar score on postoperative day 7, and ensure significantly better wound cosmesis.

CONCLUSIONS

Transverse skin incision for microscopic lumbar discectomy is an applicable alternative to classic midline or paramedian vertical incision with better esthetic results.

Minimally invasive TLIF leads to increased muscle sparing of the multifidus muscle but not the longissimus muscle compared with conventional PLIF-a prospective randomized clinical trial

BACKGROUND CONTEXT

An overload of the paravertebral muscles after surgical intervention is suggested to be the major cause of postoperative pain. In cross-sectional area analyses, increased atrophy of the multifidus muscle (MF) after conventional open versus minimally invasive posterior lumbar interbody fusion (PLIF) has been described. The three-dimensional characteristics of the paravertebral muscles and separate evaluation of the longissimus muscle (LS) have not been addressed in analyses thus far.

PURPOSE

The purpose of the present study was to compare the MF and LS volume atrophy and fatty degeneration between single-level minimally invasive transforaminal lumbar interbody fusion (miTLIF) and conventional midline approach-based PLIF (coPLIF) of L4/L5 or L5/S1 at the index and superior adjacent segments.

DESIGN

This was a prospective, randomized, controlled, non-blinded study.

PATIENT SAMPLE

Fifty patients with single-level segment degeneration (Pfirrmann ≥III and Modic ≥3) of L4/L5 or L5/S1 not requiring decompression were randomly assigned to two groups.

OUTCOME MEASURES

Paraspinal lumbar residual muscle tissue volume, change in the relative fat content of MF and LS at the index and superior adjacent segments, and clinical parameters, including a visual analogue scale (VAS) for low back pain and the Oswestry Disability Questionnaire (ODI) were the outcome measures in this study.

METHODS

Twenty-five patients were treated with miTLIF, and the remaining patients were treated with coPLIF (both with transpedicular fixation). Clinical scoring was performed preoperatively and at 1 week and 12 months postoperatively, and computed tomography was performed at the latter two follow-ups.

RESULTS

The LS damage at the index segment was similar in both groups (3% greater fat content increase in the coPLIF vs. the miTLIF group, p=.032), whereas MF atrophy and degeneration were increased (p<.001) in the coPLIF group. At the adjacent segment, muscle atrophy and increased fatty infiltration (p<.05) were minimal in both muscles but were similar in both groups. Visual analogue scale and ODI scores improved (p<.001), without differences between the groups.

CONCLUSIONS

The muscle damage after miTLIF was inferior to that after coPLIF; spatially, however, the muscle sparing was predominantly attributed to the MF and, surprisingly, not to the LS.

Anatomical Relationship between Bl23 and the Posterior Ramus of the L2 Spinal Nerve

Background

The acupuncture point BL23 is located in the region of the posterior ramus of the second lumbar spinal nerve (L2) and has historically been used to treat conditions such as lower back pain, pollakiuria, erectile dysfunction, dysmenorrhoea, tinnitus, and vertigo. Some of these treatment effects have been hypothesised to be mediated by the sympathetic nervous system. It was recently discovered that the posterior ramus of the spinal nerve (PRSN) at L2 forms not two but three branches.

Objective

To examine the relationship between the acupuncture point BL23 and the L2 PRSN in order to consider the pathways possibly affected by BL23 acupuncture.

Methods

Acupuncture needles were inserted through the skin at BL23 to a depth of 3 cm a total of 13 times in eight donor cadavers (seven right-sided, six left-sided). Leaving the needle in place, ventral dissection was performed to determine the PRSN anatomy between the L1 and L3 spinal segments. In four cadavers, the relationship between the L2 spinal nerve and sympathetic branches was additionally evaluated. Following dissection, three-dimensional (3D) data were acquired using a photo scanner and 3D structural images were created using 3D computer graphics software. One additional (female) cadaver was studied without insertion of an acupuncture needle (due to significant scoliosis).

Results

The L2 PRSN was divided into medial, intermediate and lateral branches. The needle inserted at BL23 came to lie in the region of the intermediate or lateral branches in all cases. Rami communicantes were found between the L2 spinal nerve and sympathetic trunk with fibres going on to supply the superior hypogastric plexus.

Conclusions

Our findings suggest that acupuncture needles inserted at BL23 come into close proximity with the intermediate or lateral branch of the L2 PRSN, which could result in stimulation of both the somatic and sympathetic nervous systems.