How dimensions can guide surgical planning and training: a systematic review of Kambin's triangle.

OBJECTIVE: The authors sought to analyze the current literature to determine dimensional trends across the lumbar levels of Kambin's triangle, clarify the role of imaging techniques for preoperative planning, and understand the effect of inclusion of the superior articular process (SAP). This compiled knowledge of the triangle is needed to perform successful procedures, reduce nerve root injuries, and help guide surgeons in training. METHODS: The authors performed a search of multiple databases using combinations of keywords: Kambin's triangle, size, measurement, safe triangle, and bony triangle. Articles were included if their main findings included measurement of Kambin's triangle. The PubMed, Scopus, Ovid, Cochrane, Embase, and Medline databases were systematically searched for English-language articles with no time frame restrictions through July 2022. RESULTS: Eight studies comprising 132 patients or cadavers were included in the study. The mean ± SD age was 66.69 ± 9.6 years, and 53% of patients were male. Overall, the size of Kambin's triangle increased in area moving down vertebral levels, with L5-S1 being the largest (133.59 ± 4.36 mm2). This trend followed a linear regression model when SAP was kept (p = 0.008) and removed (p = 0.003). There was also a considerable increase in the size of Kambin's triangle if the SAP was removed. CONCLUSIONS: Here, the authors have provided the first reported systematic review of the literature of Kambin's triangle, its measurements at each lumbar level, and key areas of debate related to the definition of the working safe zone. These findings indicate that CT is heavily utilized for imaging of the safe zone, the area of Kambin's triangle tends to increase caudally, and variation exists between patients. Future studies should focus on using advanced imaging techniques for preoperative planning and establishing guidelines for surgeons.

Inhibiting spinal secretory phospholipase A2 after painful nerve root injury attenuates established pain and spinal neuronal hyperexcitability by altering spinal glutamatergic signaling.

Neuropathic injury is accompanied by chronic inflammation contributing to the onset and maintenance of pain after an initial insult. In addition to their roles in promoting immune cell activation, inflammatory mediators like secretory phospholipase A2 (sPLA2) modulate nociceptive and excitatory neuronal signaling during the initiation of pain through hydrolytic activity. Despite having a known role in glial activation and cytokine release, it is unknown if sPLA2 contributes to the maintenance of painful neuropathy and spinal hyperexcitability later after neural injury. Using a well-established model of painful nerve root compression, this study investigated if inhibiting spinal sPLA2 7 days after painful injury modulates the behavioral sensitivity and/or spinal dorsal horn excitability that is typically evident. The effects of sPLA2 inhibition on altered spinal glutamatergic signaling was also probed by measuring spinal intracellular glutamate levels and spinal glutamate transporter (GLAST and GLT1) and receptor (mGluR5, GluR1, and NR1) expression. Spinal sPLA2 inhibition at day 7 abolishes behavioral sensitivity, reduces both evoked and spontaneous neuronal firing in the spinal cord, and restores the distribution of neuronal phenotypes to those of control conditions. Inhibiting spinal sPLA2 also increases intracellular glutamate concentrations and restores spinal expression of GLAST, GLT1, mGluR5, and GluR1 to uninjured expression with no effect on NR1. These findings establish a role for spinal sPLA2 in maintaining pain and central sensitization after neural injury and suggest this may be via exacerbating glutamate excitotoxicity in the spinal cord.

Direct anterior decompression of L4 and L5 nerve root in sacral fractures using the pararectus approach: a technical note.

PURPOSE: To describe a new surgical technique for neurolysis and decompression of L4 and L5 nerve root entrapment after vertical sacral fractures via the pararectus approach for acetabular fractures, and to present four case examples. PATIENTS AND METHODS: We retrospectively evaluated four patients suffering radiculopathy from entrapment of the L4 or L5 nerve root in vertical sacral fractures between January and December 2016. The mean follow-up period after surgery was 18 (range 7-27) months. All patients underwent direct decompression and neurolysis of the L4 and L5 nerve roots via the single-incision, intrapelvic, extraperitoneal pararectus approach. RESULTS: In all patients, the L4 and L5 nerve root was successfully visualized and decompressed, proving feasibility of the pararectus approach for this indication. No patient presented with a neural tear. Complete neurologic recovery was present in one patient at last follow-up; two patients had incomplete recovery of their radiculopathy; and one patient had no improvement after nerve root decompression. CONCLUSIONS: The pararectus approach allows for sufficient visualisation and direct decompression and neurolysis of the L4 and L5 nerve root entrapped in vertical sacral fractures. Although neurologic recovery was not achieved in all patients in this small case series, the approach may be a suitable alternative to posterior approaches and other anterior approaches such as the lateral window of the ilioinguinal approach.

An unusual complication of sacral nerve root injury following bone marrow harvesting: a case report.

BACKGROUND: Hematopoietic stem cell transplantation (HSCT) remains an important therapeutic option for many hematologic malignancies. Bone marrow harvesting from an appropriate donor must be conducted for hematopoietic stem cell transplantation (HSCT). Many previous studies show complications of the recipient after hematopoietic stem cell transplantation (HSCT). However, complications of the donor after bone marrow harvesting are rare. We here report a unique case of a patient who developed sacral nerve root injury after bone marrow harvesting. CASE PRESENTATION: A 26-year-old man was admitted to our medical center complaining of acute onset painful burning and tingling sensation at the left posterior thigh and calf. He was a bone marrow donor for his brother's bone marrow transplantation. He had underwent a bone marrow harvesting procedure two days before admission as a bone marrow donor, using both posterior superior iliac spine (PSIS) as the puncture site. Pelvic magnetic resonance image (MRI) showed enhancement around the left S2 nerve root in T1 and T2-weighted images. Nerve conduction studies (NCS) revealed normal conduction velocity and amplitude on both lower extremities. Electromyography (EMG) presented abnormal spontaneous activity and neurogenic motor unit potentials on the S2-innervated intrinsic foot muscle and gastrocnemius, soleus muscle on the left. The patient was treated with pregabalin for pain control. The patient was followed up after 3, 6, and 12 months. Neuropathic pain improved to Visual Analogue Scale (VAS) 1, and recovery state was confirmed by re-innervation patterns of motor unit potentials in electromyography. CONCLUSION: Bone marrow harvesting is a relatively safe procedure. However, variable complications may occur. Accurate anatomical knowledge and carefulness are required to avoid sacral nerve root injury when performing the bone marrow harvesting procedure.

[Cause analysis and clinical intervention of C 5 palsy after cervical surgery].

Objective: To review the research progress of C 5 palsy (C 5P) after cervical surgery, providing new clinical intervention ideas for the C 5P patients. Methods: The relevant literature domestically and abroad was extensively consulted and the latest developments in the incidence, risk factors, manifestations and diagnosis, prevention, and intervention measures of C 5P were systematically expounded. Results: C 5P is characterized by weakness in the C 5 nerve innervation area after cervical decompression surgery, manifested as limited shoulder abduction and elbow flexion, with an incidence rate more than 5%, often caused by segmental spinal cord injury or mechanical injury to the nerve roots. For patients with risk factors, careful operation and preventive measures can reduce the incidence of C 5P. Most of the patients can recover with conservative treatment such as drug therapy and physical therapy, while those without significant improvement after 6 months of treatment may require surgical intervention such as foraminal decompression and nerve displacement. Conclusion: Currently, there has been some advancement in the etiology and intervention of C 5P. Nevertheless, further research is imperative to assess the timing of intervention and surgical protocol.

Acupuncture promotes neurological recovery and regulates lymphatic function after acute inflammatory nerve root injury.

Aims: To investigate the therapeutic effect of acupuncture on acute inflammatory nerve root injury by regulating lymphatic function. Main methods: A mouse model of L5 nerve root compression was used to simulate acute nerve root injury. After modeling, acupuncture treatment was given each day for one week. Pain thresholds were assessed before and after modeling and treatment. Immunofluorescence staining was performed to observe the distribution astrocytes and neurons in the lumbar spinal cord, the innervation rate of neuromuscular junctions (NMJs), lymphatic endothelial cells (LECs) of lumbar aortic lymph nodes, and the percentage of M1 macrophages. The number of each type of immune cells in the lumbar aortic lymph nodes (LALNs) was measured by flow cytometry. Key findings: The model group showed a significant decrease in pain threshold in the affected lower limb, while acupuncture treatment was able to significantly increase it. Acupuncture significantly repaired astrocytes and neurons in the lumbar spinal cord of the compressed segment, increased the innervation rate of nerve endings at NMJs, reduced LECs in the LALNs, reduced the proportion of M1 macrophages in the LALNs, and significantly reduced mononuclear neutrophils and monocytic neutrophils. Significance: Acupuncture can reduce pain, promote nerve repair in mice with acute nerve root injury, and suppress immune responses in lumbar aortic lymph nodes.

Diagnostic Ability of Ultrasonography in Brachial Plexus Root Injury at Different Stages Post-trauma.

Brachial plexus (BP) root injury often results in disability of the upper extremities. Improvements in high-frequency ultrasonography have enabled the visualization of BP nerve roots. This study was aimed at quantifying the diagnostic accuracy of ultrasonography in BP root injury at different stages post-trauma. A consecutive series of 170 patients with BP root injury between 2015 and 2019 were studied retrospectively and divided into three groups on the basis of time between injury and ultrasound examination (≤1 mo, 1-3 mo, >3 mo). Diagnosis of complete BP root injury under ultrasound was determined using a pre-defined criterion, including pseudomeningocele, retraction and rupture. Diagnostic accuracy was calculated based on surgical findings and intra-operative electrophysiological tests. Rates of detection of the cervical (C5-C8) and thoracic (T1) nerve roots under ultrasound were 99.4%, 99.4%, 99.4%, 95.9% and 79.4%, respectively. The sensitivity for complete BP root injury was 0.74, and the specificity was 0.91. No significant differences in sensitivity or specificity were observed across time stages. Ultrasound exhibited substantial consistency with surgical findings (κ = 0.70) for complete BP root injury at any stage post-injury. Ultrasound can be an optional method of diagnosis of complete BP root injury at an early stage post-injury.

Monitoring spinal surgery for extramedullary tumors and fractures.

Meningiomas are the most common intradural extramedullary tumors, followed by nerve sheath tumors that can also grow extradurally. Metastases are the most frequent extradural tumors and most commonly affect the thoracic vertebrae. Spinal fractures with column dislocation and/or instability require surgical fixation. Spine surgery for an extramedullary tumor or fracture usually involves decompression of neural elements and instrumentation for stabilization. These procedures risk spinal cord and nerve root injury. The incidence of nerve root deficits after resection of nerve sheath tumors is particularly high since the tumor grows from the rootlets. Intraoperative neurophysiologic monitoring and mapping techniques have been introduced to prevent iatrogenic neurologic deficits. These include motor and sensory evoked potentials, electromyography, compound muscle action potentials, and the bulbocavernosus reflex. The combination of techniques chosen for a particular procedure depends on the surgical level and the character of the lesion.

Stretch on the L5 nerve root in high-grade spondylolisthesis reduction.

OBJECTIVE: L5 nerve root (L5-NR) injury after surgery for high-grade spondylolisthesis (HGS) was considered a nerve stretch associated with reduction. Currently, however, no study has directly measured the stretch on the L5-NR during HGS reduction procedures. METHODS: CT data of 4 patients with mild lumbar degeneration (control group [CG]) and 4 patients with HGS (spondylolisthesis group [SG]) were used for 3D printing to develop L5 vertebrae and sacrum models. These models were mounted on a self-designed reduction apparatus, which performed vertical translation (disc heights of 0, 5, and 10 mm), anterior-posterior translation (reduction, 0%-100%), and slip-angle correction (0° to -30°). The L5-NR was simulated by using a rabbit sciatic nerve. The cephalic side of the nerve was fixed at the upper base of the L5 pedicle, while the caudal side was connected to a high-precision sensor and an indicator to measure the tension (stretch) on the nerve during the reduction procedures in real time. RESULTS: The SG had shorter L5-NRs than the CG. At a 0-mm disc height, the peak tension on the L5-NR changed from 0 N (reduction 0%) to 1.81 ± 0.54 N (reduction 100%) in the SG and to 1.78 ± 0.71 N in the CG. At a 10-mm disc height, the tension changed from 1.50 ± 0.67 N to 4.97 ± 1.04 N in the SG and from 0.92 ± 0.45 N to 3.26 ± 0.88 N in the CG. In both the CG and SG, at the same disc height, all values from the complete reduction process were statistically significant. Furthermore, at the same degree of reduction, the comparisons between different disc heights were almost all statistically significant. Intergroup comparisons showed that an increased disc height would cause more tension on the L5-NR in the SG than in the CG. At a 10-mm disc height, all results between the groups demonstrated statistical significance. The slip-angle correction produced a slight increase in the tension on the L5-NR in both groups. CONCLUSIONS: Increased disc height and reduction significantly increased the tension on the L5-NR, which demonstrated a nonlinear curve. The slip-angle correction from 0° to -30° slightly increased the tension on the L5-NR. Under the same degree of reduction and restored disc height, the SG had more tension on the L5-NR than the CG.

L5 nerve root injury caused by anterolateral malpositioning of loosened S1 pedicle screws: illustrative cases.

BACKGROUND: Although malpositioning of pedicle screws into the spinal canal and intervertebral foramen can cause spinal nerve root injuries, there are few reports of L5 nerve root injuries when S1 pedicle screws have been inserted anterolaterally. The authors report two cases of L5 nerve root injury caused by anterolateral malpositioning of loosened S1 pedicle screws. OBSERVATIONS: In both patients, S1 pedicle screws were inserted toward the outside of the S1 anterior foramen, and the tip of the screws perforated the anterior sacral cortex. L5 nerve root impairment was not observed immediately after surgery. However, severe leg pain in the L5 area was observed after the S1 pedicle screws became loosened. In case 1, the symptoms could not be controlled with conservative treatment. Reoperation was performed 3 months after the initial surgery. In case 2, the symptoms gradually improved with conservative treatment because the area around the loosened S1 screw was surrounded by newly formed bone that stabilized the screws, as observed with computed tomography 1 year after surgery. LESSONS: Surgeons should recognize that anterolateral malpositioning of S1 pedicle screws can cause L5 nerve root injury. The screws should be inserted in the correct direction without loosening.

Percutaneous Transforaminal Endoscopic Removal of Spinal Shrapnel.

BACKGROUND: Gunshot injuries are one of the most common causes of the penetrating injuries of the spine. The victims of these injuries usually have neurologic deficits. Percutaneous endoscopic lumbar surgery is one of the most popular surgical spine interventions. We report a case with incomplete radiculopathy due to shrapnel located in L5 foramen that was removed by percutaneous endoscopic technique. CASE DESCRIPTION: A 23-year-old man sustaining a gunshot injury penetrating to the abdomen presented to our hospital. His first examination revealed a single gunshot wound with entry hole in the left low lumbar region without exit hole and right lower abdominal quadrant tenderness. Plain radiographs and computed tomography showed a bullet in the abdomen and left L5 transverse process fracture and shrapnel in L5 foraminal zone. The bullet was removed by abdominal surgeons without any surgical plan for the shrapnel in the foramen. He was referred to our clinic 3 weeks after discharge. Without any further neurologic deterioration, he had uninterrupted severe pain that was mostly unbearable during the night. Despite gradually increasing dosages of different drugs, his pain relief was insufficient. Percutaneous transforaminal endoscopic removal of the shrapnel was planned. CONCLUSIONS: Despite the absence of a universally approved algorithm in the treatment of spinal gunshot injuries, endoscopic technique can be kept in mind for a minimal access and invasiveness in case of indication for removal. With experience in endoscopic procedures and familiarity with surgical anatomy, the treatment of this unique case was completed successfully.

Postoperative C5 Palsy: Conjectured Causes and Effective Countermeasures.

Postoperative C5 palsy (C5 palsy) is defined as de novo or aggravating muscle weakness mainly at the C5 region with slight or no sensory disturbance after cervical spine surgery. The features of C5 palsy are as follows: 1) one-half of patients are accompanied by sensory disturbance or intolerable pain at the C5 region; 2) 92% of patients have hemilateral palsy; 3) almost all palsy occurs within a week after surgery; 4) the incidence is almost the same between the anterior and posterior approaches to the cervical spine; 5) the prognosis is relatively good even in patients with severe muscle weakness. Even now, the precise causes of C5 palsy have not yet been revealed. From the viewpoint of the kinds of nerve tissue involved, the uncertain causes of C5 palsy are divided into two theories: 1) the segmental spinal cord disorder theory and 2) the nerve root injury theory. In the former, the segmental spinal cord, particularly the anterior horn cells, is thought to be chemically damaged because of preoperative ischemia and/or the aggression of reactive oxygen during postoperative reperfusion. By contrast, in the latter, the anterior rootlet and/or nerve root are believed to be mechanically damaged because of compression force and/or distraction force. In this theory, the features of C5 palsy can be well explained from anatomical viewpoints. Additionally, various countermeasures have been proposed, such as the intermittent relaxation of the tension of the hooks to the multifidus muscles during surgery; prophylactic foraminotomy to decompress C5 nerve root; prevention of excessive posterior shift of the spinal cord, which may cause the tethering effect of the nerve root; and prevention of excessive postoperative lordotic alignment of the cervical spine. These countermeasures have been proved effective, and may support the nerve root injury theory as the main conjectured theory on the causes of C5 palsy.

Removal of Migrating Lumbar Spine Bullet: Case Report and Surgical Video.

BACKGROUND: Gunshot wounds to the spine are devastating injuries. Rarely, the bullet has been reported to migrate. Migration is associated with progressive neurologic deficits that often improve with bullet removal. The authors report a case of removal of a migrating lumbar spine bullet. This is supplemented by an operative video and a review of the literature. CASE DESCRIPTION: A 31-year-old man presented to the emergency department with multiple gunshot wounds and lower-extremity paresthesia. A ballistic injury occurred with an entry wound in the right posterior soft tissues, traversing the right paraspinal muscle and fracturing the left lumbar 5 pedicle and left lumbar 4 transverse process. The bullet was positioned within the spinal canal at the lumbar 3/4 interspace. His spinal injury was managed nonoperatively due to his traumatic injuries and findings of minimal neurologic deficit without cerebrospinal fluid leak. The patient returned to the neurosurgery clinic a year later and was found to have worsening low back pain, decreased sensation throughout the left leg, and radiating pain throughout the right leg. Imaging demonstrated the bullet had migrated caudally to the midlumbar 5 vertebral body. Given the patient's progressive symptoms and migration of the bullet fragment, informed consent was obtained for a laminectomy and removal of the intradural bullet fragment. CONCLUSIONS: Neurosurgical treatment for gunshot wounds remains controversial. Cauda equina or lumbosacral level wounds are often incomplete and may improve with surgical decompression and bullet removal. Migrating bullet fragments throughout the spine and brain lead to worsened neurologic function, which can be reversed by removal. Movement of the bullet during surgery should be expected, and intraoperative fluoroscopy and patient positioning can help to properly localize the bullet and aid in its removal.

The reliability of motor evoked potentials to predict dorsiflexion injuries during lumbosacral deformity surgery: importance of multiple myotomal monitoring.

STUDY DESIGN: Case-control analysis of transcranial motor evoked potential (MEP) responses and clinical outcome. OBJECTIVE: To determine the sensitivity and specificity of MEPs to predict isolated nerve root injury causing dorsiflexion weakness in selected patients having complex lumbar spine surgery. SUMMARY OF BACKGROUND DATA: The surgical correction of distal lumbar spine deformity involves significant risk for damage to neural structures that control muscles of ankle and toe dorsiflexion. Procedures often include vertebral translation, interbody fusion, and posterior-based osteotomies. The benefit of using MEP monitoring to predict dorsiflexion weakness has not been well-established. The purpose of this paper is to describe the relationship between neural complications from lumbar surgery and intraoperative MEP changes. METHODS: Included were 542 neurologically intact patients who underwent posterior spinal fusion for the correction of distal lumbar deformity. Two myotomes, including tibialis anterior (TA) and extensor hallucis longus (EHL), were monitored. MEP and free-running electromyography data were assessed in each patient. Cases of new dorsiflexion weakness noted postoperatively were identified. Data in case and control patients were compared. There was no direct funding for this work. The Department of Anesthesiology and Perioperative Care provides salary support for authors one and six. Authors two and three report employment in the field of intraoperative neurophysiological monitoring as a study-specific conflict of interest. RESULTS: Twenty-five patients (cases) developed dorsiflexion weakness. MEP amplitude decreased in the injured myotomes by an average of 65 ± 21% (TA) and 60±26% (EHL), which was significantly greater than the contralateral uninjured side or for control subjects. (p < .01) Receiver operator characteristic (ROC) curves showed high sensitivity, specificity, and predictive value for changes in MEP amplitude using either the TA or EHL. Analysis of MEP changes to either TA or EHL yielded a superior ROC curve. Net reclassification improvement analysis showed assessing MEP changes to both TA and EHL improved the predictability of injury. CONCLUSIONS: The use of MEP amplitude change is highly sensitive and specific to predict a new postoperative dorsiflexion injury. Monitoring two myotomes (both TA and EHL) is superior to relying on MEP changes from a single myotome. Electromyography activity was less accurate but compliments MEP use. Additional studies are needed to define optimal intraoperative MEP warning thresholds.

The incidence of nerve root injury by high-speed drill can be reduced by chilled saline irrigation in a rabbit model.

AIMS: We aimed to evaluate the temperature around the nerve root during drilling of the lamina and to determine whether irrigation during drilling can reduce the chance of nerve root injury. MATERIALS AND METHODS: Lumbar nerve roots were exposed to frictional heat by high-speed drilling of the lamina in a live rabbit model, with saline (room temperature (RT) or chilled saline) or without saline (control) irrigation. We measured temperatures surrounding the nerve root and made histological evaluations. RESULTS: In the control group, the mean temperature around the nerve root was 52.0°C (38.0°C to 75.5°C) after 60 seconds of drilling, and nerve root injuries were found in one out of 13 (7.7%) immediately, three out of 14 (21.4%) at three days, and 11 out of 25 (44.0%) at seven days post-operatively. While the RT group showed a significantly lower temperature around the nerve root compared with the control group (mean 46.5°C; 34.5°C to 66.9°C, p < 0.001), RT saline failed to significantly reduce the incidence of nerve root injury (ten out of 26; 38.5%; odds ratio (OR) 0.96; 95% confidence interval (CI) 0.516 to 1.785; p = 0.563). However, chilled saline irrigation resulted in a significantly lower temperature than the control group (mean 39.0°C; 35.3°C to 52.3°C; p < 0.001) and a lower rate of nerve root injury (two out of 21; 9.5%, OR 0.13; 95% CI 0.02 to 0.703, p = 0.010). CONCLUSION: Frictional heat caused by a high-speed drill can cause histological nerve root injury. Chilled saline irrigation had a more prominent effect than RT in reducing the incidence of the thermal injury during extended drilling. Cite this article: Bone Joint J 2017;99-B:554-60.

Salmon-derived thrombin inhibits development of chronic pain through an endothelial barrier protective mechanism dependent on APC.

Many neurological disorders are initiated by blood-brain barrier breakdown, which potentiates spinal neuroinflammation and neurodegeneration. Peripheral neuropathic injuries are known to disrupt the blood-spinal cord barrier (BSCB) and to potentiate inflammation. But, it is not known whether BSCB breakdown facilitates pain development. In this study, a neural compression model in the rat was used to evaluate relationships among BSCB permeability, inflammation and pain-related behaviors. BSCB permeability increases transiently only after injury that induces mechanical hyperalgesia, which correlates with serum concentrations of pro-inflammatory cytokines, IL-7, IL-12, IL-1α and TNF-α. Mammalian thrombin dually regulates vascular permeability through PAR1 and activated protein C (APC). Since thrombin protects vascular integrity through APC, directing its affinity towards protein C, while still promoting coagulation, might be an ideal treatment for BSCB-disrupting disorders. Salmon thrombin, which prevents the development of mechanical allodynia, also prevents BSCB breakdown after neural injury and actively inhibits TNF-α-induced endothelial permeability in vitro, which is not evident the case for human thrombin. Salmon thrombin's production of APC faster than human thrombin is confirmed using a fluorogenic assay and APC is shown to inhibit BSCB breakdown and pain-related behaviors similar to salmon thrombin. Together, these studies highlight the impact of BSCB on pain and establish salmon thrombin as an effective blocker of BSCB, and resulting nociception, through its preferential affinity for protein C.

[The causes and prevention of C5 nerve root palsy after anterior cervical decompression and fusion].

OBJECTIVE: To analyze the causes of muscular paralysis due to C5 nerve root injury after anterior cervical decompression and fusion (ACDF) and explore its prevention way. METHODS: From January 2005 to December 2015, 310 patients underwent ACDF in our hospital. Of them, 9 cases occurred muscular paralysis due to C5 nerve root injury after operation. The clinical data of 9 patients were retrospectively analyzed. There were 8 males and 1 female, aged from 51 to 84 years with an average of 64 years. Two cases underwent internal fixation and intervertebral fusion with one segment, 6 cases with two segments, 1 case with three segments. Simple deltoid muscle weakness, pain, numbness happened in 7 cases, simultaneously biceps brachii muscle weakness, pain, numbness in 2 cases. Muscle strength was 0 grade in 1 case, 1 grade in 3 cases, 2 grades in 4 cases, 3 grades in 1 case. RESULTS: The follow up time of 9 patients was more than 12 months and the longest was 24 months with an average of 14 months. Muscle strength of 7 patients recovered to 4-5 grades. Recovering time after operation was directly proportional to the degree of injury, those patients with muscle strength level more than 2, usually could have significant improvement within 3 weeks. The JOA score improved from 10.89±1.89 preoperatively to 8.92±1.91 postoperative C5 nerve root palsy to 14.48±2.10 at final follow up, with significant difference(P<0.05). CONCLUSIONS: More complicated factors result in C5 nerve root injury after ACDF. Except those suffered severe grinding contusion and amputation, most of the patients can get satisfactory prognosis. Strict control of the operation indication, selection of the right surgical segment with accurate manipulation, control of the distraction of intervertebral space and the width of the multilevel anterior cervical corpectomy, are main methods to prevent the complication.

Kirschner wire is more effective than the nerve root retractor in treating patients with disc herniation.

OBJECTIVE: To investigate the value of using Kirschner wire in the intraspinal procedures. METHODS: From May 2011 to October 2013, a total of 46 patients with a single-level lumbar disc herniation with concomitant lumbar instability were randomly assigned to two groups at the time of admission. Group 1 had 23 patients who underwent posterior lumbar fusion using a nerve root retractor to drag nerve root, and Group 2 also had 23 patients who underwent the same operation by fixing Kirschner wires in the vertebral body to drag nerve root. All of these patients were assessed with visual analog scales (VAS) and Japanese Orthopaedic Association (JOA) scores before surgery, and were followed up at the time points of one week (VAS score only), three, six, and twelve months respectively after surgery. The actual retraction time of the nerve root of each patient was also recorded during the operation. RESULTS: The differences in VAS and JOA scores were not significant between Group 1 and 2 before surgery. However, these scores showed significant improvement in Group 2 at one week and three months after surgery compared with those in Group 1. At six and twelve month follow-up time points, no significant difference was observed between these two groups. However, the retraction time of the nerve root of the patients in Group 2 was significantly shorter than in Group 1. CONCLUSIONS: Using Kirschner wires instead of the nerve root retractor to pull nerve root in the patients with a single-level lumbar disc herniation accompanied by the lumbar instability is more effective in reducing the dragging damage of the nerve root at early phases after surgery and in shortening retraction time.

S3 motor branch stimulation failure due to nerve fiber burning at the nerve-wire junction: A historical technical note.

BACKGROUND: Sacral nerve stimulation is a minimally invasive procedure to treat spinal cord injured (SCI) patients with overactive bladder syndrome or nonobstructive urinary retention that is refractory to conservative treatment. METHODS: In this paper, we report a case of traumatic cervical SCI with quadriplegia and spastic bladder, which was managed by third sacral motor branch stimulation in 1998. RESULTS: In this case, stimulation-induced burning of nerve fibers was seen microscopically during the implantation surgery. At 2 weeks after the index surgery, the stimulator was removed due to ineffectiveness. We hypothesize that the stimulation settings of our stimulator were not appropriate for neural stimulation and led to neural destruction, fibrosis, and treatment failure. CONCLUSION: The device settings of stimulators used in neural stimulation should be appropriate for direct neural stimulation otherwise they can lead to neural destruction and treatment failure.