Lumbosacral plexus avulsion with pelvic fractures

Value of Direct Decompression of Lumbosacral Roots in Sacral Fractures with Neurologic Deficit: Is It Mandatory?

Background

The value of direct decompression of neural structures to treat lumbosacral plexus injury associated with sacral fractures is still debatable. Direct decompression allows decompression of nerve roots by sacral laminectomy and removal of bone fragments in the spinal canal. In contrast, indirect decompression may offer similar neurological outcomes if good fracture reduction and correction of sacral kyphosis are achieved. In this comparative retrospective study, we analyzed differences between direct and indirect neurological decompression in terms of neurological recovery, complications, and functional outcome.

Methods

This study included 33 cases with spinopelvic dissociation with variable degrees of lumbosacral plexus injury. All cases were managed by spinopelvic fixation. Eighteen patients (group 1) had direct decompression of lumbosacral nerve roots while 15 patients (group 2) had indirect decompression.

Results

Initial sacral kyphosis, quality of fracture reduction, and postoperative residual kyphosis were the main factors that significantly affected functional and neurological outcome in both groups. The final neurological improvement was similar in both groups. No significant difference was observed between both groups in the residual Gibbons' score recorded in the last visit (p = 0.206). The final Majeed score also showed no significant difference between the two groups (p = 0.869).

Conclusions

Indirect decompression of sacral fractures showed similar final functional outcome and neurological recovery compared to direct decompression. Restoration of lumbosacropelvic stability and anatomic reduction seem to be the cornerstone for better functional outcome and neurological recovery rather than direct decompression of neural elements.

Bioinformatic analysis of circular RNA expression profiles in a rat lumbosacral spinal root avulsion model

Lumbosacral spinal root avulsion (LSRA) is a severe nerve injury that results in devastating dysfunction in the lower limb. Circular ribonucleic acids (circRNAs) have been reported to be implicated in a variety of diseases. However, the role of circRNAs in LSRA remains unclear. Here, we performed RNA sequencing (RNA-seq) to determine circRNA expression profiles in a rat LSRA model and further investigated their potential functions and the underlying mechanisms by bioinformatic analyses and in vitro experiments. In all, 1708 circRNAs were found to be differentially expressed in spinal cord tissues after LSRA (|fold change| ≥ 2 and p < 0.05), with 591 up-regulated 1117 down-regulated. Meanwhile, 2263 mRNAs were also indentified to be differentially expressed, of which 1471 were upregulated and 792 were downregulated. Eight randomly selected circRNAs and mRNA were successfully verified to be consistent the RNA-seq results by quantitative real-time polymerase chain reaction. Functional analyses based on gene ontology and Kyoto Encyclopedia of Genes and Genomes predicted the potential roles of differentially expressed circRNAs and mRNAs in LSRA, and circRNA/miRNA/mRNA interaction networks revealed that circRNA_7025, a down-regulated circRNA in LSRA, was targeted by two neuronal apoptosis-related miRNAs, rno-miR-1224 and rno-miR-326-5p. Further in vitro experiments revealed that circRNA_7025 protected against oxygen-glucose deprivation induced neuronal apoptosis via the circRNA_7025/miR-1224/miR-326-5p axis. In summary, our results revealed circRNA expression profiles and their potential functions in LSRA. These findings improve our understanding of the pathogenic mechanisms involved in LSRA and might enable us to identify new molecular targets for LSRA.

Epitranscriptomic analysis of m6A methylome in rats after lumbosacral nerve root avulsion

Background: N⁶-methyladenosine (m⁶A) is the most prevalent modification in mRNAs but its role in lumbosacral nerve root avulsion (LSRA) remains elusive. Materials & methods: Mettl3 expression and global m⁶A level were detected by qPCR, western blot and immunostaining. Altered m⁶A-tagged transcript profiles were revealed by methylated RNA immunoprecipitation and RNA sequencing. Results: Mettl3 and global m⁶A level were upregulated in spinal cord tissues of LSRA rats. In all, 1087 m⁶A peaks were differentially modified by m⁶A, of which 654 were upregulated and 433 downregulated. Biological functions of these transcripts and the hypermethylated or hypomethylated transcripts were also identified. Conclusion: Our findings revealed a profound function of m⁶A modification in LSRA, which provides new insights into its pathogenesis.

Up-regulation of heat shock protein 27 inhibits apoptosis in lumbosacral nerve root avulsion-induced neurons

Lumbosacral nerve root avulsion leads to widespread death of neurons in the anterior horn area of the injured spinal cord, which results in dysfunction in the lower extremities. Heat shock protein 27 (Hsp27) has been found to play cytoprotective roles under adverse conditions. However, the role of Hsp27 in neurons after lumbosacral nerve root avulsion is unknown. The aim of the present study was to investigate the effects and mechanism of action of Hsp27 on neurons after lumbosacral nerve root avulsion. It was found that Hsp27 expression was elevated in the anterior horn area of the injured spinal cord and the up-regulation of Hsp27 protected neurons against apoptosis after lumbosacral nerve root avulsion. In addition, Hsp27 plays an anti-apoptotic role by suppressing oxidative stress reactions. These findings indicated that Hsp27 may play a key role in resistance to lumbosacral nerve root avulsion-induced neuron apoptosis and may prove to be a potential strategy for improving prognosis after lumbosacral nerve root avulsion.

Demystifying MR Neurography of the Lumbosacral Plexus: From Protocols to Pathologies

Magnetic resonance neurography is a high-resolution imaging technique that allows evaluating different neurological pathologies in correlation to clinical and the electrophysiological data. The aim of this article is to present a review on the anatomy of the lumbosacral plexus nerves, along with imaging protocols, interpretation pitfalls, and most common pathologies that should be recognized by the radiologist: traumatic, iatrogenic, entrapment, tumoral, infectious, and inflammatory conditions. An extensive series of clinical and imaging cases is presented to illustrate key-points throughout the article.

Risk factors for lumbosacral plexus palsy related to pelvic fracture

STUDY DESIGN

A retrospective study.

OBJECTIVE

We assessed risk factors for lumbosacral plexus palsy related to pelvic fracture that can be evaluated during the acute injury phase with diagnostics such as computed tomography (CT).

SUMMARY OF BACKGROUND DATA

Many patients with pelvic fracture are in vital shock, with polytrauma and loss of consciousness, making an accurate neurologic examination very difficult in the emergency room.

METHODS

This study included 22 patients who had AO classification type B or C pelvic fractures. The 22 patients had 27 posterior osteoligamentary lesions. The average injury severity score (ISS) was 27.5 (range, 16-50). Age, sex, ISS, suicidal jump, longitudinal displacement, sacral transverse fracture, pubic fracture, lumbar transverse process fracture, type of pelvic fracture (AO), and type of sacral fracture (Denis) were examined for a correlation with the lumbosacral plexus palsy. Using coronal reconstruction CT, we considered a 10 mm or greater displacement at the sacrum or sacroiliac joint to be a longitudinal displacement. Transverse sacral fracture was diagnosed by sagittal reconstruction CT.

RESULTS

Of the 22 patients, 5 (22.7%) had lumbosacral plexus palsy (8 of 27 pelvic fractures) detected during treatment. The incidence of lumbosacral plexus palsy was not related to age, sex, ISS. Incidence of palsy was significantly higher when the patient's affected side had longitudinal displacement. Patients who had made a suicidal jump or had a sacral transverse fracture also had a significantly higher risk for lumbosacral plexus palsy. Palsy was not related to the type of pelvic fracture (AO) or sacral fracture (Denis).

CONCLUSION

In this study, longitudinal displacement of the pelvis, transverse sacral fracture, and trauma from a suicidal jump were risk factors for lumbosacral plexus palsy. These risk factors were helpful in our examination of patients who had severe pelvic fracture with loss of consciousness.

Traumatic lumbosacral pseudomeningocele associated with spinal fracture

BACKGROUND CONTEXT

Traumatic pseudomeningocele and avulsion of lumbosacral nerve roots are rare in the absence of fractures of the pelvic ring or hip dislocation. Clear prognoses for the root avulsion or pseudomeningocele do not exist.

PURPOSE

To present a patient who developed a posttraumatic pseudomeningocele after lumbosacral injury.

STUDY DESIGN

Case report and review of the literature.

METHODS

A patient who sustained traumatic pseudomeningocele of the lumbar spine was treated nonsurgically and followed over a 2-year period.

RESULTS

Nerve root deficit largely recovered, although an asymptomatic pseudomeningocele persisted.

CONCLUSIONS

The radiographic diagnosis of lumbar root avulsion is not predictive, and recovery may be expected in some patients without operative intervention. Management of patients with lumbar nerve root avulsion and posttraumatic pseudomeningocele should be based on the size and clinical significance of the pseudomeningocele.

Neurologic Injury Associated With Pelvic Trauma: Radiology and Electrodiagnosis Evaluation and Their Relationships to Pain and Gait Outcome

OBJECTIVES

To study the electrodiagnosis presentation of patients with lower-extremity nerve injury related to pelvic trauma, to assess gait outcome and correlation to injury type and electrodiagnosis, and to study the incidence of pain postinjury and the relationships between injury type and electrodiagnosis and pain type.

DESIGN

Retrospective review.

SETTING

Tertiary care university hospital.

PARTICIPANTS

Seventy-eight patients who present with lower-extremity nerve injury associated with pelvic trauma.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Electrodiagnostic results, the relationship between electrodiagnosis and fracture or injury type, and gait and pain outcomes.

RESULTS

The characteristic neurologic injury in patients with pelvic trauma was a lumbosacral plexus injury (71% of cases). Sciatic nerve injuries were more common in patients with isolated acetabular fractures (9/10 cases). Gait outcome was related to electrodiagnostic abnormality and severity. Long-term assisted gait was best predicted by absent peroneal conduction to the extensor digitorum brevis (P<.001) and absent motor unit potentials on anterior tibialis needle examination (P<.001). Neuropathic pain was seen in patients with any degree of gait abnormality. Orthopedic pain was more common in patients with an acetabular fracture (P<.025).

CONCLUSIONS

Lumbosacral plexus injury after pelvic trauma is a characteristic disorder with severe long-term implications regarding both pain and gait outcome.

Lumbosacral nerve root avulsion

Lumbosacral nerve root avulsion is a rare clinical entity. Since the first description in 1955, only 35 cases have been reported. It is often associated with pelvic fractures and may be missed in the initial clinical examination as these patients usually present with multiple injuries. We present three such cases with clinical and radiological findings. These patients were involved in road traffic accidents. Two had fractures of the sacroiliac joint with diastasis of the symphysis pubis (Tile type C 1.2) and one had fractures of the public rami (Tile type B 2.1). All three had various degrees of sensory and motor deficit of the lower limbs. Lumbar myelogram shows characteristic pseudomeningoceles in the affected lumboscral region. Magnetic resonance (MR) imaging provides an additional non-invasive modality to diagnose this condition.

Neurologic injuries in pelvic ring fractures

Unstable fractures of the pelvic ring are an increasingly frequent outcome of motor vehicle trauma. Neurologic injury after such injuries can be a cause of significant morbidity. The available literature on neurologic injuries was reviewed and compared with a clinical review of 90 unstable pelvic injuries treated during a 3-year period. Eighty-three patients were available for followup examination. Neurologic injuries were seen in 21 % of the patients. Thirty-seven percent of patients had sensory deficits alone whereas the remaining 63% had motor and sensory findings. All patients showed some evidence of neurologic recovery at an average or 24-months followup. At least 1 grade of muscle function improvement was consistently seen and 53% of patients had complete neurologic recovery. Improvement in function was seen as many as 24 months postinjury, but L5 function was least likely to progress to full recovery. The incidence of neurologic injuries and their distribution was similar to that reported in the literature, whereas the prognosis for neurologic recovery was significantly better. This may be related to techniques of early anatomic reduction and stabilization of unstable pelvic ring injuries.