BACKGROUND: Current research lacks comprehensive investigation into the biomechanical changes in the spinal cord and nerve roots during scoliosis correction. This study employs finite element analysis to extensively explore these biomechanical variations across different Cobb angles, providing valuable insights for clinical treatment.
METHODS: A personalized finite element model, incorporating vertebrae, ligaments, spinal cord, and nerve roots, was constructed using engineering software. Forces and displacements were applied to achieve Cobb angle improvements, designating T1/2-T4/5 as the upper segment, T5/6-T8/9 as the middle segment, and T9/10-L1/2 as the lower segment. Simulations under traction, pushing, and traction + torsion conditions were conducted, and biomechanical changes in each spinal cord segment and nerve roots were analyzed.
RESULTS: Throughout the scoliosis correction process, the middle spinal cord segment consistently exhibited a risk of injury under various conditions and displacements. The lower spinal cord segment showed no significant injury changes under traction + torsion conditions. In the early correction phase, the upper spinal cord segment demonstrated a risk of injury under all conditions, and the lower spinal cord segment presented a risk of injury under pushing conditions. Traction conditions posed a risk of nerve injury on both sides in the middle and lower segments. Under pushing conditions, there was a risk of nerve injury on both sides in all segments. Traction + torsion conditions implicated a risk of injury to the right nerves in the upper segment, both sides in the middle segment, and the left side in the lower segment. In the later correction stage, there was a risk of injury to the upper spinal cord segment under traction + torsion conditions, the left nerves in the middle segment under traction conditions, and the right nerves in the upper segment under pushing conditions.
CONCLUSIONS: When the correction rate reaches 61-68%, particular attention should be given to the upper-mid spinal cord. Pushing conditions also warrant attention to the lower spinal cord and the nerve roots on both sides of the main thoracic curve. Traction conditions require attention to nerve roots bilaterally in the middle and lower segments, while traction combined with torsion conditions necessitate focus on the right-side nerve roots in the upper segment, both sides in the middle segment, and the left-side nerve roots in the lower segment.

UNASSIGNED: To observe the possibility of hyper selective neurectomy (HSN) of triceps branches combined with partial neurotomy of S 2 nerve root for relieving spastic equinus foot.
UNASSIGNED: Anatomical studies were performed on 12 adult cadaveric specimens. The S 2 nerve root and its branches were exposed through the posterior approach. Located the site where S 2 joined the sciatic nerve and measured the distance to the median line and the vertical distance to the posterior superior iliac spine plane, and the S 2 nerve root here was confirmed to have given off branches of the pelvic splanchnic nerve, the pudendal nerve, and the posterior femoral cutaneous nerve. Between February 2023 and November 2023, 4 patients with spastic equinus foot were treated with HSN of muscle branches of soleus, gastrocnemius medial head and lateral head, and cut the branch where S 2 joined the sciatic nerve. There were 3 males and 1 female, the age ranged from 5 to 46 years, with a median of 26 years. The causes included traumatic brain injury in 2 cases, cerebral hemorrhage in 1 case, and cerebral palsy in 1 case. The disease duration ranged from 15 to 84 months, with a median of 40 months. The triceps muscle tone measured by modified Ashworth scale (MAC) before operation was grade 3 in 2 cases and grade 4 in 2 cases. The muscle strength measured by Daniels-Worthingham manual muscle test (MMT) was grade 2 in 1 case, grade 3 in 1 case, and 2 cases could not be accurately measured due to grade 4 muscle tone. The Holden walking function grading was used to evaluate lower limb function and all 4 patients were grade 2. After operation, triceps muscle tone, muscle strength, and lower limb function were evaluated by the above grading.
UNASSIGNED: The distance between the location where S 2 joined the sciatic nerve and median line was (5.71±0.53) cm and the vertical distance between the location and posterior superior iliac spine plane was (6.66±0.86) cm. Before joining the sciatic nerve, the S 2 nerve root had given off branches of the pelvic splanchnic nerve, the pudendal nerve, and the posterior femoral cutaneous nerve. All the 4 patients successfully completed the operation, and the follow-up time was 4-13 months, with a median of 7.5 months. At last follow-up, the muscle tone of the patients decreased by 2-3 grades when compared with that before operation, and the muscle strength did not decrease when compared with that before operation. Holden walking function grading improved by 1-2 grades, and there was no postoperative hypoesthesia in the lower limbs.
UNASSIGNED: HSN of triceps branches combined with partial neurotomy of S 2 nerve root can relieve spastic equinus foot without damaging other sacral plexus nerves.
UNASSIGNED: 探讨小腿三头肌肌支超选择性神经切断术（hyper selective neurectomy，HSN）联合S 2神经根部分切断缓解痉挛性马蹄足的可行性。.
UNASSIGNED: 采用12具成人尸体标本进行解剖学研究，从后路显露S 2神经根及其分支，寻找S 2神经根汇入坐骨神经的部位，测量其到中线的距离以及到髂后上棘平面的垂直距离，并确认此处的S 2神经根是否已经发出盆内脏神经、阴部神经以及股后皮神经的分支。2023年2月—11月，对4例痉挛性马蹄足患者采用比目鱼肌及腓肠肌内、外侧头肌支HSN联合S 2神经根汇入坐骨神经分支切断进行治疗。男3例，女1例；年龄5～46岁，中位年龄26岁。病因包括脑外伤2例，脑出血1例，脑瘫1例。病程15～84个月，中位时间40个月。术前小腿三头肌跖屈肌张力改良Ashworth分级（MAC）为3级2例、4级2例；Daniels-Worthingham徒手肌力分级（MMT）评定肌力为2级1例、3级1例，2例因肌张力4级而无法准确测量术前肌力；Holden步行功能分级评价下肢功能，4例患者均为2级。术后采用上述分级评价小腿三头肌跖屈肌张力、肌力及下肢功能。.
UNASSIGNED: S 2神经根汇入坐骨神经位置至中线的距离为（5.71±0.53）cm，至髂后上棘平面的垂直距离为（6.66±0.86）cm。在汇入坐骨神经前S 2神经根已发出盆内脏神经、阴部神经以及股后皮神经的分支。4例患者均顺利完成手术，随访时间4～13个月，中位时间7.5个月。末次随访时，患者肌张力较术前下降2～3级，肌力较术前无下降，Holden步行功能分级提升1～2级，均无下肢感觉减退。.
UNASSIGNED: 小腿三头肌肌支HSN联合S 2神经根部分切断可缓解痉挛性马蹄足，且不损伤其余骶丛。.

OBJECTIVE: Although ipsilateral C7 nerve transfer is used for the treatment of C5-C6 brachial plexus injuries, accurately evaluating the functional quality of the donor nerve (ipsilateral C7 nerve root) is difficult, especially when the C7 nerve root is slightly injured. The purpose of this study was to determine the indicators to evaluate the quality of the ipsilateral C7 nerve and assess the clinical outcomes of this procedure.
METHODS: This study employed the following three indicators to assess the quality of the ipsilateral C7 nerve: (1) the muscle strength and electrophysiological status of the latissimus dorsi, triceps brachii, and extensor digitorum communis; (2) the sensibility of the radial three digits, especially the index finger; and (3) the intraoperative appearance, feel and electrophysiological status of the ipsilateral C7 nerve root. Transfer of the ipsilateral C7 nerve root to the upper trunk was implemented only when the following three tests were conducted, the criteria were met, and the clinical outcomes were assessed in eight patients with C5-C6 brachial plexus injuries.
RESULTS: Patients were followed-up for an average of 90 ± 42 months. At the final follow-up, all eight patients achieved recovery of elbow flexion, with five and three patients scoring M4 and M3, respectively, according to the Medical Research Council scoring. The shoulder abduction range of motor recovery averaged 86 ± 47° (range, 30°-170°), whereas the shoulder external rotation averaged 51 ± 26° (range, 15°-90°).
CONCLUSIONS: Ipsilateral C7 nerve transfer is a reliable and effective option for the functional reconstruction of the shoulder and elbow after C5-C6 brachial plexus injuries when the three prerequisites are met.

BACKGROUND: Central nervous system (CNS) disorders, such as stroke, often lead to spasticity, which result in limb deformities and significant reduction in quality of life. Spasticity arises from disruptions in the normal functioning of cortical and descending inhibitory pathways in the brainstem, leading to abnormal muscle contractions. Contralateral seventh cervical nerve cross transfer (CC7) surgery has been proven to effectively reduce spasticity, but the specific mechanism for its effectiveness is unclear.
METHODS: This study aimed to investigate the changes in the dorsal root ganglia (DRG) following CC7 surgery. A comprehensive anatomical analysis was conducted through cadaveric study and magnetic resonance imaging (MRI) study, to accurately measure the regional anatomy of the C7 DRG. DRG perfusion changes were quantitatively assessed by comparing pre- and postoperative dynamic contrast-enhanced (DCE) MRI.
RESULTS: In CC7 surgery, the C7 nerve root on the affected side is cut close to the DRG (3.6 ± 1.0 mm), while the C7 nerve root on the healthy side is cut further away from the DRG (65.0 ± 10.0 mm). MRI studies revealed that after C7 proximal neurotomy on the affected side, there was an increase in DRG volume, vascular permeability, and perfusion; after C7 distal neurotomy on the healthy side, there was a decrease in DRG volume, with no significant changes in vascular permeability and perfusion.
CONCLUSIONS: This study provides preliminary insights into the mechanisms of spasticity reduction following CC7 surgery, indicating that changes in the DRG, such as increased vascular permeability and perfusion, could disrupt abnormal spinal γ-circuits. The resulting high-perfusion state of DRG, possibly due to heightened neuronal activity and metabolic demands, necessitating further research to verify this hypothesis.

UNASSIGNED: Nerve injury is a serious complication of percutaneous endoscopic transforaminal lumbar discectomy due to nerve root contact. The maximum tolerable concentration (MTC) of ropivacaine concentration for epidural anaesthesia, is defined as the concentration that minimises pain while preserving the sensation of the nerve roots. This distinct advantage allows the patient to provide feedback to the surgeon when the nerve roots are contacted.
UNASSIGNED: We used a biased-coin design to determine the MTC, which was estimated by the 10% effective concentration (EC10), ie, the concentration at which 10% of patients lost sensation in the nerve roots. The determinant for positive response was lack of sensory feedback upon contact with the nerve root, and the feedback from occurrence of sensations in the innervation area upon contact with the nerve root was defined as a negative response. Primary outcome was the response from contact nerve root. Secondary outcomes were the type and number of statements of negative response and each patient\'s pain score during surgery.
UNASSIGNED: Fifty-four patients were included in this study. The EC10 was 0.434% (95% CI: 0.410%, 0.440%) using isotonic regression in comparison with 0.431% (95% CI: 0.399%, 0.444%) using probit regression. Three type statements of negative response were reported including \"tactile sensation\", radiculalgia, and numbness.
UNASSIGNED: The MTC of ropivacaine used for epidural anaesthesia was 0.434% to avoid nerve injury in percutaneous endoscopic transforaminal lumbar discectomy.

BACKGROUND Functional evaluation after therapeutic selective nerve root block (SNRB) has been rarely reported. We explored functional outcomes of SNRB for single-segment lumbar spinal stenosis (LSS). MATERIAL AND METHODS Data for 117 patients with single-segment LSS who underwent single therapeutic SNRB were retrospectively collected between January 2019 and December 2021. Functional outcomes were assessed using Oswestry Disability Index (ODI) and Japanese Orthopaedic Association (JOA) scores preoperatively, and 3 days, and 3, 6, and 12 months after SNRB, which were compared in subgroups stratified by age, sex, BMI, sedentary time, hypertension, diabetes, affected side, pathology level, intervertebral disk. Correlation between ODI and JOA was analyzed using univariate linear regression analysis. RESULTS Clinical symptoms of LSS significantly improved within 12 months after SNRB, especially at 6 months (P<0.05). ODI scores in each subgroup gradually decreased within 6 months after SNRB, and JOA scores gradually increased. Most subgroup analyses revealed significantly increased ODI scores and decreased JOA scores at 12 months after SNRB, compared with 6-month scores (P<0.05). Notably, ODI and JOA scores at 12 months after SNRB were not significantly different than those before SNRB in patients with BMI >25 or sedentary time >8 h (P>0.05). A significant correlation existed between ODI and JOA scores (P<0.05). CONCLUSIONS Therapeutic SNRB was an effective treatment for alleviating LSS within at least 6 months. Changing sedentary habits with appropriate exercise and controlling weight with a healthy diet can improve the effectiveness of SNRB, especially in patients for whom conservative treatment is ineffective and who are unsuitable for surgical treatment.

METHODS: The study included 2 fresh-frozen cadavers.
OBJECTIVE: To elucidate the positional relationship between surgical instruments and nerve roots during full endoscopic facet-sparing (FE fs-TLIF) and full endoscopic facet-resecting (FE fr-TLIF) transforaminal lumbar interbody fusion and propose safe instrumentation insertion procedures and recommend cage glider designs aimed at protecting nerve roots.
BACKGROUND: Endoscopic surgical techniques are increasingly used for minimally invasive lumbar fusion surgery, with FE fr-TLIF and FE fs-TLIF being common approaches. However, the risk of nerve root injury remains a significant concern during these procedures.
METHODS: Eight experienced endoscopic spine surgeons performed uniportal FE fr-TLIF and FE fs-TLIF on cadaveric lumbar spines, totaling 16 surgeries. Postoperation, soft tissues were removed to assess the positional relationship between the cage entry point and nerve roots. Distances between the cage entry point, traversing nerve root, and exiting nerve root were measured. Safe instrumentation design and insertion procedures were determined.
RESULTS: In FE fr-TLIF, the mean distance between the cage entry point and traversing nerve root was significantly shorter compared with FE fs-TLIF (3.30 ± 1.35 vs . 8.58 ± 2.47 mm, respectively; P < 0.0001). Conversely, the mean distance between the cage entry point and the exiting nerve root was significantly shorter in FE fs-TLIF compared with FE fr-TLIF (3.73 ± 1.97 vs . 6.90 ± 1.36 mm, respectively; P < 0.0001). For FE fr-TLIF, prioritizing the protection of the traversing root using a 2-bevel tip cage glider was crucial. In contrast, for FE fs-TLIF, a single-bevel tip cage glider placed in the caudal location was recommended.
CONCLUSIONS: This study elucidates the anatomic relationship between cage entry points and nerve roots in uniportal endoscopic lumbar fusion surgery. Protection strategies should prioritize the traversing root in FE fr-TLIF and the exiting root in FE fs-TLIF, with corresponding variations in surgical techniques.
METHODS: Level V.

BACKGROUND: Radiofrequency thermocoagulation (RFT) of the thoracic nerve root is commonly employed in treating medication-refractory thoracic post-herpetic neuralgia (PHN). However, RFT procedures\' suboptimal pain relief and high occurrence of postoperative skin numbness present persistent challenges. Previous single-cohort research indicated that the low-temperature plasma coblation technique may potentially improve pain relief and reduce the incidence of skin numbness. Nevertheless, conclusive evidence favoring coblation over RFT is lacking.
OBJECTIVE: To compare the clinical outcomes associated with coblation to those associated with RFT in the treatment of refractory PHN.
METHODS: Retrospective matched-cohort study.
METHODS: Affiliated Hospital of Capital Medical University.
METHODS: Sixty-eight PHN patients underwent coblation procedures between 2019 and 2020, and 312 patients underwent RFT between 2015 and 2020 in our department. A matched-cohort analysis was conducted based on the criteria of age, gender, weight, pain intensity, pain duration, side of pain, and affected thoracic dermatome. Pain relief was assessed using the numeric rating scale (NRS), the Medication Quantification Scale (MQS) Version III and the Neuropathic Pain Symptom Inventory (NPSI), which were employed to indicate pain intensity, medication burden, and comprehensive pain remission at 6, 12, and 24 months. Numbness degree scale scores and complications were recorded to assess safety.
RESULTS: We successfully matched a cohort of 59 patients who underwent coblation and an equivalent number of patients who underwent RFT as a PHN treatment. At the follow-up time points, both groups\' NRS, MQS, and NPSI scores exhibited significant decreases from the pre-operation scores (P < 0.05). The coblation group\'s NRS scores were significantly lower than the RFT group\'s at the sixth and the twenty-fourth months (P < 0.05). At 24 months, the MQS values in the coblation group were significantly lower than those in the RFT group (P < 0.05). Furthermore, the coblation group\'s total intensity scores on the NPSI were significantly lower than the RFT group\'s at the 12- and 24-month follow-ups (P < 0.05). At 6 months, the coblation group\'s temporary intensity scores on the NPSI were significantly lower than the RFT group\'s (P < 0.05). Notably, the occurrence of moderate or severe numbness in the coblation group was significantly lower than in the RFT group at 6 and 12 months (P < 0.05). No serious adverse effects were reported during the follow-up.
CONCLUSIONS: This analysis was a single-center retrospective study with a small sample size.
CONCLUSIONS: In this matched cohort analysis, coblation achieved longer-term pain relief with a more minimal incidence rate of skin numbness than did RFT. Further randomized controlled trials should be conducted to solidify coblation\'s clinical superiority to RFT as a PHN treatment.

UNASSIGNED: To review the research progress of C 5 palsy (C 5P) after cervical surgery, providing new clinical intervention ideas for the C 5P patients.
UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 综述颈椎术后C 5麻痹（C 5 palsy，C 5P）研究进展，为临床治疗C 5P患者提供参考。.
UNASSIGNED: 广泛查阅国内外颈椎术后C 5P相关文献，系统性阐述C 5P发病机制、危险因素、临床表现及诊断、预防、治疗措施新进展。.
UNASSIGNED: C 5P为颈椎术后出现的C 5神经支配区肌肉无力，表现为肩外展、屈肘受限，发生率>5%，可能由节段性脊髓损伤或神经根机械损伤导致。对于存在危险因素患者，术中仔细操作及采取预防性措施可减少术后C 5P的发生。大部分患者经药物治疗、物理治疗等保守治疗后功能可恢复，6个月以上无明显好转者可予以手术干预，可选用椎间孔减压、神经移位等手术方案。.
UNASSIGNED: 有关C 5P发病机制及预防措施等已取得一定研究进展，但对于干预时机和手术方式仍需进一步研究。.

UNASSIGNED: To explore the predictive value of the nerve root sedimentation sign in the diagnosis of lumbar spinal stenosis (LSS).
UNASSIGNED: Between January 2019 and July 2021, 201 patients with non-specific low back pain (NS-LBP) who met the selection criteria were retrospectively analyzed. There were 67 males and 134 females, with an age of 50-80 years (mean, 60.7 years). Four intervertebral spaces (L 1, 2, L 2, 3, L 3, 4, L 4, 5) of each case were studied, with a total of 804. The nerve root sedimentation sign was positive in 126 intervertebral spaces, and central canal stenosis was found in 203 intervertebral spaces. Progression to symptomatic LSS was determined by follow-up for lower extremity symptoms similar to LSS, combined with central spinal stenosis. Univariate analysis was performed for gender, age, visual analogue scale (VAS) score for low back pain at initial diagnosis, treatment, dural sac cross-sectional area at each intervertebral space, number of spinal stenosis segments, lumbar spinal stenosis grade, positive nerve root sedimentation sign, and number of positive segments between patients in the progression group and non-progression group, and logistic regression analysis was further performed to screen the risk factors for progression to symptomatic LSS in patients with NS-LBP.
UNASSIGNED: All patients were followed up 17-48 months, with an average of 32 months. Of 201 patients with NS-LBP, 35 progressed to symptomatic LSS. Among them, 33 cases also had central spinal stenosis, which was defined as NS-LBP progressing to symptomatic LSS (33 cases in progression group, 168 cases in non-progression group). Univariate analysis showed that CSA at each intervertebral space, the number of spinal stenosis segments, lumbar spinal stenosis grade, whether the nerve root sedimentation sign was positive, and the number of nerve root sedimentation sign positive segments were the influencing factors for the progression to symptomatic LSS ( P<0.05); and further logistic regression analysis showed that positive nerve root sedimentation sign increased the risk of progression of NS-LBP to symptomatic LSS ( OR=8.774, P<0.001).
UNASSIGNED: The nerve root sedimentation sign may be associated with the progression of NS-LBP to symptomatic LSS, and it has certain predictive value for the diagnosis of LSS.
UNASSIGNED: 探索神经根沉降征在腰椎管狭窄症（lumbar spinal stenosis，LSS）诊断中的预测价值。.
UNASSIGNED: 回顾分析2019年1月—2021年7月收治且符合选择标准的201例非特异性腰痛（non-specific low back pain，NS-LBP）患者，其中男67例，女134例；年龄50～80岁，平均60.7岁。研究每例L 1、2、L 2、3、L 3、4、L 4、5椎间隙，共804个；其中126个椎间隙神经根沉降征阳性，203个椎间隙中央椎管狭窄。通过随访是否出现类似LSS的下肢症状，结合是否合并中央椎管狭窄确定患者是否向症状性LSS进展。对进展组和未进展组患者的性别、年龄、初诊时腰部疼痛视觉模拟评分（VAS）评分、治疗情况、各节段椎间隙硬膜囊面积（dural sac cross-sectional area，CSA）、椎管狭窄节段数、腰椎管狭窄分级、神经根沉降征阳性与否、沉降征阳性节段数进行单因素分析，并进一步行logistic回归分析，筛选NS-LBP患者向症状性LSS进展的危险因素。.
UNASSIGNED: 患者均获随访，随访时间17～48个月，平均32个月。201例患者中，35例在初诊至末次随访期间出现过类似LSS的下肢症状，其中33例同时合并中央椎管狭窄（进展组33例，未进展组168例）。单因素分析示各节段椎间隙CSA、椎管狭窄节段数、腰椎管狭窄分级、神经根沉降征阳性与否、沉降征阳性节段数等指标是进展为症状性LSS的影响因素（ P<0.05）；进一步logistic回归分析示，神经根沉降征阳性会增加NS-LBP向症状性LSS进展风险（ OR=8.774， P<0.001）。.
UNASSIGNED: 神经根沉降征阳性可能与NS-LBP进展为症状性LSS相关，对LSS的诊断有一定预测价值。.