Total dorsal ramus block for the treatment of chronic low back pain: a preliminary study

Predicting spatio-temporal radiofrequency ablation temperature using deep neural networks

Radiofrequency ablation (RFA) of the medial branch nerve is a widely used therapeutic intervention for facet joint pain. However, denervation of the multifidus muscle is an inevitable consequence of RFA. New ablation techniques with the potential to prevent muscle denervation can be designed using computational simulations. However, depending on the complexity of the model, they could be computationally expensive. As an alternative approach, deep neural networks (DNNs) can be used to predict tissue temperature during RFA procedure. The objective of this paper is to predict the tissue spatial and temporal temperature distributions during RFA using DNNs. First, finite element (FE) models with a range of distances between the probes were run to obtain the temperature readings. The measured temperatures were then used to train the DNNs that predict the spatio-temporal temperature distribution within the tissue. Finally, a separate data obtained from FE simulations were used to test the efficacy of the network. The results presented in this paper demonstrate that the network can achieve an error rate as low as 0.05%, accompanied by a 92% reduction in time compared to FE simulations. The approach proposed in this study will play a major role in the design of new RFA treatments for facet joint pain.

Assessment and nonsurgical management of low back pain: a narrative review

Low back pain (LBP) is a common condition that affects people of all ages and income levels worldwide. The etiology of LBP may be mechanical, neuropathic, systemic, referred visceral, or secondary to other causes. Despite numerous studies, the diagnosis and management of LBP remain challenging due to the complex biomechanics of the spine and confounding factors, such as trivial degenerative imaging findings irrelevant to symptoms and psychological and emotional factors. However, it is imperative to identify the crucial signs ("red flags") indicating a serious underlying condition. While many recent guidelines emphasize non-pharmacologic management approaches, such as education, reassurance, and physical and psychological care, as the first option, LBP patients in many countries, including South Korea, are prescribed medications. Multidisciplinary rehabilitation combined with prudent use of medications is required in patients unresponsive to first-line therapy. The development of practical guidelines apposite for South Korea is needed with multidisciplinary discussion.

Ultrasound-guided total dorsal ramus block for the treatment of chronic low back pain

Background:

To reduce the risk of radiation exposure, we explored whether the total dorsal ramus block can be performed under ultrasound guidance. We evaluated the accuracy and effect of ultrasound-guided total dorsal ramus block for chronic low back pain.

Methods:

Accuracy of ultrasound guidance after total dorsal ramus block to the L4–L5 level was evaluated using fluoroscopy ( n = 5). A second group was assigned into two groups: ultrasound-guided group ( n = 19) or fluoroscopy-guided group ( n = 18). The effects and adverse events were compared.

Results:

In all cases, the fluoroscopic findings revealed an accurate injection at the L5 level. Significant alleviation of pain was observed after ultrasound-guided total dorsal ramus block, and comparable effectiveness was observed with both ultrasound guidance and fluoroscopic guidance. There were no complications.

Conclusions:

The ultrasound-guided total dorsal ramus block may sufficiently block all three branches of the lumbar dorsal ramus at the targeted level resulting in significant pain reduction.

Are dorsal ramus nerve blocks the solution to postoperative lumbar spine surgery pain?

Background

Open lumbar spine surgery typically results in significant post-operative pain. Most pain protocols promote a multimodal approach aiming to reduce opiate requirements. This case-matched, prospective clinical study aims to establish the efficacy of dorsal ramus nerve root (DRN) blocks for post-operative analgesia.

Methods

We conducted a case-control observational, single centre, prospective study of 15 consecutive patients who had DRN block for a single-level lumbar discectomy or one/two-level lumbar spinal decompression, from Jan 2018 to Jun 2018. These were case matched with a field infiltration group. We analyse for differences in mean and maximum rest pain scores, opiate requirement, mobilisation status and length of stay (LoS).

Results

No differences were seen in pain scores in the first 24 hours post-operation for DRN block vs. field infiltration groups (2.8 vs. 2.7, P=0.90). No reduction in the morphine sulphate equivalents dosage requirement was seen in the DRN group (43.1±46.4 vs. 37.6±33.5, P=0.26). Similar proportions of patients mobilised early (P=1.0) and the mean LoS was 1.7 vs. 1.8 days (P=0.81).

Conclusions

Dorsal ramus nerve block is not superior to local anaesthetic field infiltration of surgical wound in minor one or two level lumbar spinal decompression surgery in terms of alleviating pain, reducing opiate requirements, or facilitating earlier mobilisation and discharge.

A prospective randomized double-blind trial of the efficacy of a bilateral lumbar erector spinae block on the 24h morphine consumption after posterior lumbar inter-body fusion surgery

BACKGROUND

Spine surgery is associated with considerable postoperative pain and can be challenging to treat. A loco-regional technique suitable for spine surgery should cover the dorsal root of the spinal nerves at the levels where surgery is performed. The erector spinae block is a loco-regional technique with promising results and was recently described at the thoracic level. There are no randomized trials of this technique on a lumbar level. This study tests the hypothesis that the 24-h postoperative morphine consumption is significantly lower in patients undergoing posterior lumbar inter-body fusion surgery with a lumbar erector spinae (LUMBES) block when compared with a sham block.

METHODS

This prospective randomized double-blind multicenter study will randomly allocate 80 adult patients undergoing elective posterior lumbar inter-body fusion surgery during general anesthesia to one of two groups as follows: (1) bilateral erector spinae block (20 mL 0.25% levobupivacaine) or (2) bilateral sham block (20 mL NaCl 0.9%). Our primary endpoint is 24-h postoperative morphine consumption. Secondary endpoints include 72-h morphine consumption, intraoperative sufentanil dosage, postoperative pain scores at regular time intervals both at rest and during movement, time to first postoperative mobilization, and the Quality of Recovery 40 survey score.

DISCUSSION

The LUMBES trial is a pragmatic clinical study that will provide evidence of whether a bilateral lumbar erector spinae block is effective in reducing 24-h postoperative morphine consumption in patients undergoing lumbar inter-body fusion surgery. If this hypothesis is confirmed, this finding could contribute to more widespread implementation of this technique.

TRIAL REGISTRATION

Local ethics committee B300201837508, ClinicalTrials.gov identifier: NCT03825198 . Registered on 31 Jan 2019.

Impact of Position on Efficacy of Caudal Epidural Injection for Low Back Pain and Radicular Leg Pain Due to Central Spinal Stenosis and Lumbar Disc Hernia

Objective

This study was performed to evaluate and compare the efficacies of caudal epidural injections performed at prone and lateral decubitus positions.

Methods

A total of 120 patients suffering from low back pain and radicular leg pain were included and patients were randomly distributed into 2 groups according to the position during injection. In Group 1 (n=60; 32 women, 28 men), caudal epidural injection was performed at prone position, whereas it was implemented at lateral decubitus position in Group 2 (n=60; 33 women, 27 men). Visual analogue scale, Oswestry Disability Index (ODI), walking tolerance (WT) and standing tolerance (ST) were compared in 2 groups before and after injection.

Results

In Group 1, ODI values were higher at 30th minute (p=0.007), 3rd week (p=0.043) and 6th month (p=0.013). In Group 1, ODI, VAS and ST values were improved significantly at all follow-up periods compared to initial values. In Group 1, WT scores were better than initial values at 30th minute, 3rd week and 3rd month. In Group 2, ODI scores at 30th minute, 3rd week, 3rd month and 6th month were improved while VAS and ST scores were improved at all periods after injection. WT scores were better at 30th minute, 3rd week and 3rd month compared to initial WT scores.

Conclusion

Our results indicated that application of injection procedure at lateral decubitus position allowing a more concentrated local distribution may provide better relief of pain.

A new look at trigger point injections

Trigger point injections are commonly practised pain interventional techniques. However, there is still lack of objective diagnostic criteria for trigger points. The mechanisms of action of trigger point injection remain obscure and its efficacy remains heterogeneous. The advent of ultrasound technology in the noninvasive real-time imaging of soft tissues sheds new light on visualization of trigger points, explaining the effect of trigger point injection by blockade of peripheral nerves, and minimizing the complications of blind injection.

Prevalence, Spinal Alignment, and Mobility of Lumbar Spinal Stenosis with or without Chronic Low Back Pain: A Community-Dwelling Study

Although lumbar spinal stenosis (LSS) occurs almost universally with aging, little is known regarding its actual prevalence and relationships to chronic low back pain (CLBP) in the general population. The presence of CLBP in subjects with LSS may have negative impacts on spinal alignment and mobility. This study evaluated the prevalence of LSS using a self-administered, self-reported history questionnaire in 630 community-dwelling individuals ≥50 years old. Subjects with LSS were further divided into LSS+CLBP and LSS alone groups, and spinal alignment and mobility were compared using a computer-assisted device. Prevalence of LSS was 10.8% in this cohort. Subjects in the LSS+CLBP group (n = 46) showed a significantly more kyphotic lumbar spinal alignment with limited lumbar extension (P < .05), resulting in a stooped trunk compared to subjects in the LSS alone group (n = 22). However, no significant difference in spinal mobility was seen between groups.