Anatomic Study of Superior Cluneal Nerves: Application to Low Back Pain and Surgical Approaches to Lumbar Vertebrae

Patient satisfaction with cluneal nerve entrapment surgery

INTRODUCTION

Low back pain (LBP) from superior or middle cluneal nerve entrapment has been addressed surgically. We recorded patient satisfaction with this treatment.

METHODS

We included 22 consecutive patients who had undergone surgery for unilateral cluneal nerve entrapment (superior: n = 17, middle: n = 5). The numerical rating scale (NRS) for LBP, the Oswestry Disability Index (ODI) score, and the EuroQOL 5-dimension, 5-level (EQ-5D-5L) scale before and 6 months after the operation were compared. Using these scores, the treatment outcome was compared with the patients' preoperative expectations.

RESULTS

LBP was ameliorated in all 22 patients; their NRS, ODI, and EQ-5D-5L were significantly improved after surgery. Surgical satisfaction based on the postoperative NRS scores was recorded as 8.8 ± 1.1 (range 7-10). While the postoperative was significantly better than the expected NRS, the postoperative ODI was significantly higher than expected by the patients (both: p < 0.05). There was a moderate correlation between the postoperative NRS and ODI and postoperative patient satisfaction.

CONCLUSION

Patient satisfaction with the surgical result was rated as acceptable.

Radiofrequency Ablation of the Superior Cluneal Nerve: A Novel Minimally Invasive Approach Adopting Recent Anatomic and Neurosurgical Data

Objectives/Introduction

Superior cluneal neuralgia (SCN) is a distinct cause of lower back and/or leg pain related to pathology of the superior cluneal nerve (SCn). SCN has been termed pseudo-sciatica and is an overlooked differential diagnosis when patients are otherwise presenting with low back and/or radicular pain. Radiofrequency ablation (RFA) is commonly used for denervation of the medial branches of the dorsal root for facet joint syndrome for sacroiliac joint; however, RFA has not been described to ablate the SCn for SCN. Herein, we present a novel interventional minimally invasive approach using RFA of the SCn for SCN in a series of 46 patients.

Methods

Institutional review board approved retrospective chart review was used to collect data for all SCn RFA cases from January 1, 2018, to February 8, 2021. Fluoroscopically guided SCn ablations were performed for patients with a positive “iliac crest point sign,” reproductive of their back and leg pain during physical examination. Sensory stimulation was utilized to confirm RF cannula-probe placement adjacent to the SCn, and motor testing was used to confirm no distal motor response prior to monopolar RF ablation with a Halyard RF Generator (100 mm curved 22G 10 mm active tip RF cannulae). Charts were reviewed for time of analgesia follow-up, duration and degree of analgesia, improvements in patients’ functional capacity, and changes in medication.

Results

Data were reviewed for 51 patients who underwent Scn RFA, 5 of which were lost to follow-up. The remaining 46 patients consisted of 29 women and 17 men with a mean age of 59.4 years; 78.3% (n = 36) had ongoing relief at a mean of 92.1 days follow-up, ranging from 13 to 308 days, with a mean of 92.3% analgesia (SD 15.0%). At a mean of 111.2 days of follow-up, ranging from 42–201 days, 21.7% (n = 10) of patients reported that their pain had returned and had 95% analgesia during that time period (SD 6.7%); 41.3% (n = 19) reported improved activity/gait, 17.4% reported improved mood (n = 8), and 8.7% reported decreased medication use (n = 4). Five patients had minor complications including bruising (1), 2–3 days of soreness on site (2), myofascial pain (1), and quadratus lumborus muscle spasm relieved with trigger point injection (1).

Conclusions

This is the first report of both technique and outcomes for radiofrequency ablation of superior cluneal neuralgia. This series suggests that RFA of the SCn is a suitable intervention for the treatment of SCN; 21.7% of patients reported a mean of 95% analgesia for a mean duration of 111.2 days, and the remaining 78.3% of patients reported ongoing relief with a mean of 92.3% analgesia at last follow-up (mean 92.1 days). There were no serious adverse events.

Transmuscular quadratus lumborum block for postoperative pain and recovery after laparoscopic adrenalectomy: a randomized controlled trial

Background

To investigate the role of transmuscular quadratus lumborum block (TMQLB) for postoperative pain control, patient satisfaction and recovery in laparoscopic adrenalectomy.

Methods

Seventy-two patients aged between 18 and 70 years with an ASA I-II and scheduled for laparoscopic adrenalectomy were randomized to receive a single-shot TMQLB with 0.4 ml/kg 0.5 % ropivacaine or 0.4 ml/kg 0.9 % saline as placebo. The primary endpoint was pain on movement at 12 h after surgery evaluated by the numeric rating scale (NRS, 0–10). P-values < 0.05 was considered statistically significant. The secondary outcomes included pain at rest and pain on movement evaluated by the NRS, and postoperative recovery related parameters.

Results

NRS on movement at 12 h after surgery was lower in the TMQLB group compared with the control (median 2 vs. 3, p = 0.024). Intraoperative fentanyl consumption was lower in the TMQLB group (247.08 ± 63.54 vs. 285.44 ± 74.70, p = 0.022). The rate of using postoperative rescue tramadol was also lower in the TMQLB group (5.6 vs. 27.8 %, p = 0.027). Similar incidences of nausea and vomiting were observed (11.1 vs. 25 %, p = 0.220). Patient satisfaction of pain service was better in the TMQLB group (83.3 vs. 25 %, p < 0.001) with shorter time to ambulation (16.5 vs. 21 h, p = 0.004) and flatus (18.5 vs. 23.5 h, p = 0.006).

Conclusions

TMQLB showed better control of postoperative pain on movement for laparoscopic adrenalectomy with improved patients’ satisfaction of anesthesia, shorter time to ambulation and flatus.

Trial registration

This study was registered at Clinicaltrials.gov (NCT03942237; registration date: 08/05/2019; enrollment date: 10/05/2019).

Rare variation of the furcal nerve

Variations in the course of the lumbar plexus and lumbosacral trunk have been explored with respect to variant nerve roots being indicated in atypical sciatic pain. Typically, the furcal nerve emerges from the L4 nerve root, with a single contribution. However, we report a case where the furcal nerve was found to arise not only from the L4 nerve but also from the obturator nerve. This anatomical variation is explored in terms of its clinical significance and implications in lumbar and sacral plexus associated procedures.

Pain Syndromes Secondary to Cluneal Nerve Entrapment

PURPOSE OF REVIEW

The purpose of this review is to provide an overview of the cluneal nerves, present a summary of pain syndromes secondary to clunealgia, and evaluate current literature for diagnostic and treatment modalities.

RECENT FINDINGS

Multiple trials and studies have reported success with numerous modalities ranging from nerve blocks, neuroablation, and even peripheral neuromodulation with varying degrees of clinical benefit. Cluneal nerve entrapment or chronic impingement can cause buttock pain or referred pain to nearby areas including the lower back, pelvic area, or even the lower extremities. Clunealgias and associated pain syndromes can often be challenging to diagnose and differentiate. An appreciation of the pathophysiology of clunealgias can assist with patient selection for interventional pain strategies targeted towards the cluneal nerves, including nerve blocks, neuroablation, and peripheral neuromodulation. More research is needed to better delineate the efficacy of these procedures for clunealgias.

The supraorbital and supratrochlear nerves for ipsilateral corneal neurotization: anatomical study

Neurotrophic keratitis is a rare corneal disease that is challenging to treat. Corneal neurotization (CN) is among the developing treatments that uses the supraorbital (SON) or supratrochlear (STN) nerve as a donor. Therefore, the goal of this study was to provide the detailed anatomy of these nerves and clarify their feasibility as donors for ipsilateral CN. Both sides of 10 fresh-frozen cadavers were used in this study, and the SON and STN were dissected using a microscope intra- and extraorbitally. The topographic data between the exit points of these nerves and the medial and lateral angle of the orbit were measured, and nerve rotation of these nerves toward the ipsilateral cornea were attempted. The SON and STN were found on 19 of 20 sides. The vertical and horizontal distances between the exit point of the SON and that of the STN, were 7.3±2.1 mm (vertical) and 4.5±2.3 mm, respectively. The mean linear distances between the medial angle and the exit points of each were 22.2±3.0 mm and 14.5±1.9 mm, respectively, and the mean linear distances between the lateral angle and the exit points of the SON and STN were 34.0±2.7 mm and 36.9±2.5 mm, respectively. These nerves rotated ipsilaterally toward the center of the orbit easily. A better understanding of the anatomy of these nerves can contribute to the development and improvement of ipsilateral CN.

Posterior Sacrococcygeal Plexus: Application to Spine Surgery and Better Understanding Low-Back Pain

OBJECTIVE

The sacral dorsal rami form the posterior sacrococcygeal plexus (PSCP), which has been scantly studied. This study's goal was to clarify the PSCP s detailed anatomy and discuss its clinical relevance.

METHODS

Ten sides of 5 fresh-frozen cadavers were dissected for this research. After the muscles covering the sacrum were removed, the PSCP was identified and traced under the operating microscope until the entire plexus was exposed. The contributions to this plexus and its relations to surrounding anatomic structures were recorded.

RESULTS

The PSCP was found on all sides and was composed of a medial trunk (MT), communicating branches, and a lateral trunk. Each sacral dorsal ramus's MT formed a series of loops created by adjacent sacral dorsal rami placed between the transverse tubercles and the posterior sacral foramina. The MT, communicating branches, and lateral trunk demonstrated potential entrapment sites.

CONCLUSIONS

To our knowledge, this is the first anatomic study that provides detailed images that indicate 3 potential sites where surrounding structures could entrap the PSCP. Knowledge of its detailed anatomy might help in better understanding low-back pain, targeting pain sources and guide spine surgeons for avoiding injury to these nerves.

Anatomic Study of Superior Cluneal Nerves: Revisiting the Contribution of Lumbar Spinal Nerves

OBJECTIVE

Superior cluneal nerve (SCN) entrapment neuropathy can result in low back pain and thus be confused with other pathologies (e.g., lumbar disk disease). Therefore we performed cadaveric dissection of the SCN to better understand its anatomy and segmental origin.

METHODS

Twenty sides from 10 Caucasian fresh frozen cadavers (6 females and 4 males) were used in this study. The diameter of the SCN, distance between the exit point of the SCN from the thoracolumbar fascia and midline, and distance between the exit point of the SCN from the thoracolumbar fascia and the posterior superior iliac spine to the medial and lateral SCN were measured. The segmental origins of the SCNs were verified.

RESULTS

Seventy-five percent of the dorsal rami of L1, 90% of L2, 95% of L3, 45% of L4, and 10% of L5 contributed to the SCN. The SCN was formed by 3 vertebral levels in 55% and by 4 vertebral levels in 30%. Three SCNs pierced the thoracolumbar fascia in 45%.

CONCLUSIONS

The origin of the SCN, which has been described in the textbook and literature for a long time, should be reconsidered on the basis of our study results.

Anatomic Study of the Superior Cluneal Nerve and Its Related Groove on the Iliac Crest

OBJECTIVE

Superior cluneal nerve entrapment neuropathy is one cause of low back pain often referred to as "pseudo sciatica." Studies have found that the superior cluneal nerve can arise variably from T11 to L5. The osteofibrous tunnels formed by a groove on the iliac crest might compress the superior cluneal nerve. Therefore, the purpose of this study was to investigate the origin of the superior cluneal nerve and its course through such bony grooves.

METHODS

Twenty sides from 10 fresh frozen Caucasian cadavers were used in this study. Once both the superior cluneal nerve and its groove were identified, the distance from the groove to the posterior superior iliac spine and midline was measured.

RESULTS

A total of 12 grooves were identified in 11 of 20 sides (55%). On 10 sides, the nerve running on the groove was the medial branch of the superior cluneal nerve. The mean distance from the bony groove to the posterior superior iliac spine and midline was 45.2 ± 11.2 mm and 65.3 ± 8.2 mm, respectively.

CONCLUSIONS

These results could help identify such bony grooves and better understand low back pain and its related anatomy.

The majority of piriformis muscles are innervated by the superior gluteal nerve

The piriformis muscle is clinically implicated in pain disorders, posterior approaches for total hip arthroplasty, and iatrogenic injury to the muscle and the surrounding nerves. The piriformis muscle has been said to receive innervation from L5 to S3 ventral rami with most sources using S1 and S2 ventral rami as the most common innervation this muscle. However, descriptions of the nerve in the literature are vague. Therefore, the aim of this study was to clarify the anatomy of the nerve supply to the piriformis muscle. Twenty sides from ten fresh-frozen cadavers were studied. Specifically, via anterior dissection of the sacral plexus, branches to the piriformis were identified. Once identified, the nerves to the piriformis muscle were traced proximally to clarify their origin. Nerves supplying the piriformis muscle existed on all sides. On 80% of sides, the piriformis was innervated by two to three nerves. The origin of these nerves was from the superior gluteal nerve on 14 sides (70%), inferior gluteal nerve on one side (5%), L5 ventral ramus on one side (5%), S1 ventral ramus on 17 sides (85%), and S2 ventral ramus on 14 sides (70%), respectively. The most common nerve branches to the piriformis are from the superior gluteal nerve, and the ventral rami of S1 and S2. Based on our study, a single "nerve to piriformis" does not exist in the majority of specimens thus this term should be abandoned. Clin. Anat. 32:282-286, 2019. © 2018 Wiley Periodicals, Inc.