Fractured vertebra antedisplacement reconstruction technique: a feasible treatment choice for posttraumatic thoracolumbar kyphosis.

OBJECTIVE: The goal of this study was to evaluate the feasibility of the fractured vertebra antedisplacement reconstruction technique for the treatment of posttraumatic thoracolumbar kyphosis (PTK). METHODS: A total of 22 patients with PTK who were treated with the fractured vertebra antedisplacement reconstruction technique were retrospectively analyzed. The radiological evaluation included global kyphosis, thoracolumbar angle, and sagittal vertical axis. The clinical evaluation included visual analog scale pain score, Oswestry Disability Index score, SF-12 Health Survey score, and American Spinal Injury Association grade. The complications were recorded. RESULTS: The mean global kyphosis was 55.0° ± 12.6° preoperatively, 8.5° ± 5.0° postoperatively, and 10.3° ± 4.8° at the latest follow-up (p < 0.001). The average total kyphosis correction achieved was 44.7° ± 14.2°, with a range of 23.4°-79.4°, indicating a mean final correction of 80.1%. The mean thoracolumbar angle was 46.2° ± 13.2° preoperatively, 6.6° ± 4.5° postoperatively, and 7.6° ± 4.2° at the latest follow-up (p < 0.001). The mean sagittal vertical axis was improved significantly, from 51.1 ± 24.2 mm preoperatively to 28.5 ± 17.4 mm at the latest follow-up (p = 0.001). One patient (4.5%) experienced single intervertebral fusion nonunion, and 1 patient (4.5%) experienced distal screw loosening. No patients experienced any neurological deterioration. The visual analog scale pain score, Oswestry Disability Index score, SF-12 Health Survey score, and American Spinal Injury Association grade achieved significant improvement at the latest follow-up. CONCLUSIONS: Fractured vertebra antedisplacement reconstruction technique can effectively correct kyphosis, reconstruct spinal stability, and improve the patient's symptoms and neurological function. This technique is safer, minimally traumatic, and less technically demanding to avoid osteotomy-related complications. It is a feasible treatment choice for PTK.

[Clinical study on the treatment of postoperative recurrence of lumbar disc herniation with intervertebral fusion].

OBJECTIVE: To explore clinical effect of different intervertebral fusion devices (cage) in treating postoperative recurrent lumbar disc herniation (LDH). METHODS: One hundred and forty-two LDH patients with recurrence after simple intervertebral disc nucleus pulpoideectomy from January 2019 to January 2021 were retrospectively analyzed. All patients were treated with combined underchannel fixation and interbody fusion and divided into a single anatomical group,two-anatomical group and a single banana group according to types and numbers of implanted cage. There were 51 patients in a single anatomical group,included 29 males and 22 females,aged from 39 to 65 years old with an average of (53.74±5.68) years old;body mass index (BMI) ranged from 18.62 to 28.13 kg·m-2 with an average of (22.08±2.15) kg·m-2;the interval between operation and recurrence ranged from 0.5 to 4.0 years with an average of (2.7±0.8) years;5 patients with L3,4,35 patients with L4,5 and 11 patients with L5S1;a single anatomical cage was implanted. There were 46 patients in two-anatomical group,included 25 males and 21 females,aged from 37 to 66 years old with an average of (54.52±6.02) years old;BMI ranged from 18.25 to 28.44 kg·m-2 with an average of (21.74±1.83) kg·m-2;the interval between operation and recurrence ranged from 0.5 to 5.0 years with an average of (2.7±0.9) years;4 patients with L3,4,32 patients with L4,5 and 10 patients with L5S1;two-anatomical cages were implanted. There were 45 patients in a single banana group,included 22 males and 23 females,aged from 38 to 65 years old with an average of (54.49±6.45) years old;BMI ranged from 18.85 to 28.20 kg·m-2 with an average of (21.63±1.59) kg·m-2;the interval between operation and recurrence ranged from 0.5 to 5.0 years with an average of (2.6±1.0) years;3 patients with L3,4,36 patients with L4,5 and 16 patients with L5S1;a single banana cage was implanted. Operation time,intraoperative blood loss,incision length,postoperative incision drainage volume,hospital stay and complications among 3 groups were observed and compared. The height of intervertebral space before and after operation,curvature of lordosis and the postoperative intervertebral fusion were compared. Visual analogue scale (VAS) and Oswestry disability index (ODI) were used to evaluate degree of lumbar pain and lumbar function before operation,1 and 6 months after operation,respectively. RESULTS: All patients among 3 groups were followed up at least 6 months,and no cases were fell out. There were no significant difference in operation time,intraoperative blood loss,incision length,postoperative incision drainage volume and hospital stay among 3 groups (P>0.05). At 6 months after operation,the height of intervertebral space in two-anatomical group and a single group were [(11.08±1.78) mm,(10.95±1.62) mm],curvature of lordosis were [(12.05±1.86) °,(11.63±1.57) °],which were higher than those in a single dissection group (10.14±1.54) mm,(10.92±1.45) °,and the difference were statistically significant (P<0.05). The interbody fusion rate between two-anatomical and a banana group (95.65%,95.56%) were higher than that in a single anatomical group (78.43%) at 6 months after operation (P<0.05). VAS and ODI of lumbar among 3 groups were decreased at 1 and 6 months after operation (P<0.05). There was no significant difference in complications among 3 groups (P>0.05). CONCLUSION: The three fusion devices could achieve significant results in treating postoperative recurrence of LDH,but the implantation of two-anatomical cage and a single banana cage are more helpful to maintain the height of intervertebral space and lordosis curvature of patients with postoperative recurrence of LDH,and obtain good intervertebral fusion results.

[Herniation of intervertebral disc into thoracolumbar fracture vertebral body leads to malunion of fracture and decrease of intervertebral space height].

OBJECTIVE: To analyze the clinical characteristics of intervertebral disc tissue injury and herniation into the vertebral body in thoracolumbar fracture on fracture healing, vertebral bone defect volume and intervertebral space height. METHODS: From April 2016 to April 2020, a total of 140 patients with thoracolumbar single vertebral fracture combined with upper intervertebral disc injury treated with pedicle screw rod system reduction and internal fixation in our hospital. There were 83 males and 57 females, aged from 19 to 58 years old, with an average age of (39.33±10.26) years old. All patients were followed up regularly 6 months, 12 months and 18 months after surgery. The patients with injured intervertebral disc tissue not herniated into the fractured vertebral body were the control group, and the patients with injured intervertebral disc and herniated into the fractured vertebral body were the observation group. By detecting the thoracolumbar AP and lateral X-ray films, CT and MRI of the thoracolumbar segment at different follow-up time, calculate the changes of the wedge angle of the fractured vertebral body, the sagittal kyphosis angle and the height of the superior adjacent intervertebral space, the changes of the fracture healing and bone defect volume after the reduction of the vertebral body, and the changes of the intervertebral disc degeneration grade. The prognosis was evaluated by visual analogue scale(VAS) and Oswestry disability index(ODI). Finally, the differences of the above results among different groups were comprehensively analyzed. RESULTS: All the patients had normal wound healing without complications. A total of 87 patients received complete follow-up data, at least 18 months after internal fixation. Thoracolumbar AP and lateral X-ray films showed that 18 months after the reduction and internal fixation operation, the vertebral wedge angle, sagittal kyphosis angle and the height of the upper adjacent intervertebral space in the observation group were greater than those in the control group(P<0.05). CT scanning showed that the deformity of the fracture healed 12 months after the vertebral body reduction in the observation group and formed a "cavity" of bone defect connected with the intervertebral space, and its volume was significantly increased compared with that before (P<0.05). MRI scanning showed that the degeneration rate of injured intervertebral discs in the observation group was more serious than that in the control group 12 months after operation(P<0.05). However, there was no significant difference in VAS and ODI score at each time. CONCLUSION: Herniation of injured intervertebral disc tissue hernias into the fractured vertebral body leads to increased bone resorption defect volume around the fracture and forms a malunion "cavity" connected with the intervertebral space. This may be the main reason for the change of vertebral wedge angle, the increase of sagittal kyphosis angle and the decrease of intervertebral space height after removal of internal fixation devices.

Lumbar Spine Infection with Eikenella corrodens Presented as Abdominal Pain: A Case Report and Literature Review.

Background: Eikenella corrodens is a part of the inherent flora on the surface of human mucosa. It usually does not cause disease unless the patient has been bitten, injured or surgically infected. Lumbar spine infection caused by Eikenella corrodens usually presents with conventional symptoms such as low back pain and fever. Herein, we report a case of lumbar intervertebral space infection with Eikenella corrodens presented as abdominal pain. Case Presentation: A 38-year-old man with no medical history of note presented with abdominal pain. Initially, local doctors suspected that the patient had abdominal disease. However, abdominal diseases were ruled out and only lumbar spine infection was confirmed. Then, the patient was misdiagnosed as lumbar tuberculosis. Finally, anaerobic culture and metagenomic next-generation sequencing confirmed the Eikenella corrodens, which was rarely involved in lumbar intervertebral space infection. The patient recovered after operation and antibiotic therapy. Conclusion: This case indicated a rare symptom of lumbar spine infection, abdominal cramping, which is caused by Eikenella corrodens. Blood culture had low sensitivity as a diagnostic method for Eikenella corrodens, but lesion sample culture or metagenomic next-generation sequencing had high sensitivity for early diagnosis.

Effects of Different Intervertebral Space Heights on Nerve Root Tension during Posterior Lumbar Interbody Fusion.

OBJECTIVE: There is no effective standard method to evaluate whether the nerve root tension is restored during lumbar decompression surgery, which is an important indicator for the recovery of nerve function. This study aimed to investigate the feasibility of intraoperative nerve root tension measurement and to confirm the correlation between nerve root tension and intervertebral space height. METHODS: A total of 54 consecutive patients (mean age, 54.3 years; range, 25-68 years) received posterior lumbar interbody fusion (PLIF) for lumbar disc herniation (LDH) with lumbar spinal stenosis and instability. The 110%, 120%, 130%, 140% height values of each lesion were calculated based on preoperative measurements of the intervertebral space height. The heights were intraoperatively expanded after the intervertebral disc was removed using the interbody fusion cage model. The tension value of nerve root was measured by pulling the nerve root for 5 mm with a self-made measuring device. The nerve root tension value was measured before decompression, after discectomy at 100%, 110%, 120%, 130%, and 140% of the height of each intervertebral space, and after placement of the cage during intraoperative nerve root tension monitoring. RESULTS: The nerve root tension values at 100%, 110%, 120%, and 130% heights were significantly lower than those before decompression, and there was no statistical significance among the four groups. The nerve root tension value was significantly higher at 140% height and was statistically significant compared with that of 130% height. The nerve root tension value after cage placement was significantly lower than that before decompression (1.32 ± 0.22 N vs. 0.61 ± 0.17 N, p < 0.01), and the postoperative VAS score was also significantly improved (7.0 ± 2.24 vs. 0.8 ± 0.84, p < 0.01). The nerve root tension was positively correlated with the VAS score (F = 85.19, p < 0.01; F = 78.65, p < 0.01). CONCLUSION: This study demonstrates that nerve root tonometry can perform instant noninvasive intraoperative nerve root tension measurement. There is a correlation between nerve root tension value and VAS score. We found that when the height of the intervertebral space was increased to 140% of the original height, the nerve root tension increased the risk of injury significantly.

[Effectiveness of trans-intervertebral space osteotomy combined with cage implantation for old thoracolumbar compression fracture with kyphosis].

Objective: To investigate the effectiveness of trans-intervertebral space osteotomy (TIO) combined with cage implantation in treatment of old thoracolumbar compression fracture with kyphosis. Methods: A clinical data of 59 patients with old thoracolumbar compression fracture and kyphosis, who met the selection criteria between January 2010 and August 2020, was retrospectively analyzed. Among them, 20 cases underwent TIO combined with cage implantation (group A), 21 patients underwent TIO (group B), and 18 patients underwent pedicle subtraction osteotomy (PSO; group C). There was no significant difference in gender, age, time from injury to operation, fracture segment, and preoperative Cobb angle, average height of functional spinal unit (FSU), sagittal vertical axis (SVA), visual analogue scale (VAS) score, Japanese Orthopedic Association (JOA) score, and Oswestry disability index (ODI) between groups (P>0.05). The operation time, intraoperative blood loss, and postoperative complications were recorded. Imaging review was performed to observe the fusion of the bone graft. Cobb angle, average height of FSU, and SVA were measured. VAS score, JOA score, and ODI were used to evaluate the degree of low back pain and lumbar function. Frankel grading was used to evaluate neurological function. Results: The operations of 3 groups were successfully completed. The operation time and intraoperative blood loss were significantly lower in groups A and B than in group C (P<0.05); there was no significant difference between group A and group B (P>0.05). All incisions healed by first intention. Patients in all groups were followed up 23-27 months, with an average of 24.8 months. There was no significant difference in follow-up time between groups (P>0.05). At last follow-up, VAS score, JOA score, ODI, and SVA of 3 groups significantly improved when compared with those before operation (P<0.05), there was no significant difference in the differences of pre- and post-operation between groups (P>0.05). The neurological function grading of 3 groups was Frankel grade E. The Cobb angle and the average height of FSU in 3 groups at immediate and last follow-up significantly improved when compared with preoperative ones (P<0.05), there was no significant difference between immediately after operation and last follow-up (P>0.05). And there were significant differences in above indexes between groups at each time point (P<0.05). At last follow-up, the osteotomy site fused without internal fixation failure or pseudarthrosis formation were observed in 3 groups. Conclusion: For patients with old thoracolumbar compression fractures with kyphosis, the effectiveness of TIO combined with cage implantation is satisfactory. Compared with TIO and PSO, it can obtain more deformity correction degree and less invasive.

Herniation of intervertebral disc into thoracolumbar fracture vertebral body leads to malunion of fracture and decrease of intervertebral space height / 中国骨伤

OBJECTIVE@#To analyze the clinical characteristics of intervertebral disc tissue injury and herniation into the vertebral body in thoracolumbar fracture on fracture healing, vertebral bone defect volume and intervertebral space height.@*METHODS@#From April 2016 to April 2020, a total of 140 patients with thoracolumbar single vertebral fracture combined with upper intervertebral disc injury treated with pedicle screw rod system reduction and internal fixation in our hospital. There were 83 males and 57 females, aged from 19 to 58 years old, with an average age of (39.33±10.26) years old. All patients were followed up regularly 6 months, 12 months and 18 months after surgery. The patients with injured intervertebral disc tissue not herniated into the fractured vertebral body were the control group, and the patients with injured intervertebral disc and herniated into the fractured vertebral body were the observation group. By detecting the thoracolumbar AP and lateral X-ray films, CT and MRI of the thoracolumbar segment at different follow-up time, calculate the changes of the wedge angle of the fractured vertebral body, the sagittal kyphosis angle and the height of the superior adjacent intervertebral space, the changes of the fracture healing and bone defect volume after the reduction of the vertebral body, and the changes of the intervertebral disc degeneration grade. The prognosis was evaluated by visual analogue scale(VAS) and Oswestry disability index(ODI). Finally, the differences of the above results among different groups were comprehensively analyzed.@*RESULTS@#All the patients had normal wound healing without complications. A total of 87 patients received complete follow-up data, at least 18 months after internal fixation. Thoracolumbar AP and lateral X-ray films showed that 18 months after the reduction and internal fixation operation, the vertebral wedge angle, sagittal kyphosis angle and the height of the upper adjacent intervertebral space in the observation group were greater than those in the control group(P<0.05). CT scanning showed that the deformity of the fracture healed 12 months after the vertebral body reduction in the observation group and formed a "cavity" of bone defect connected with the intervertebral space, and its volume was significantly increased compared with that before (P<0.05). MRI scanning showed that the degeneration rate of injured intervertebral discs in the observation group was more serious than that in the control group 12 months after operation(P<0.05). However, there was no significant difference in VAS and ODI score at each time.@*CONCLUSION@#Herniation of injured intervertebral disc tissue hernias into the fractured vertebral body leads to increased bone resorption defect volume around the fracture and forms a malunion "cavity" connected with the intervertebral space. This may be the main reason for the change of vertebral wedge angle, the increase of sagittal kyphosis angle and the decrease of intervertebral space height after removal of internal fixation devices.

Diagnosis and Treatment of Klebsiella Pneumoniae Combined with Enterobacter Cloacae in Lumbar Intervertebral Space Infection / 中山大学学报(医学科学版)

ObjectiveTo explore the clinical diagnosis and treatment of rare primary lumbar intervertebral space infection with Klebsiella pneumoniae and Enterobacter cloacae， and provide clinical experience for the diagnosis and treatment of this rare spinal infection. MethodsAn elderly male patient with low back pain and numbness in the left lower extremity for more than 7 months， which aggravated for more than 1 week， was diagnosed with lumbar disc herniation after laboratory and imaging examinations. After admission， the symptoms became acutely aggravated， and re-examination of lumbar enhanced MRI showed local enhancement at the posterior edge of the L3/4 intervertebral space. The VAS score was 9 points， and the lumbar JOA score was 6 points. A posterior lumbar interbody fusion of L3-L5 was performed， and L3/4 intervertebral disc specimens were collected during the operation for bacterial culture. ResultsBacterial culture results showed Klebsiella pneumoniae and Enterobacter cloacae infection. The patient was treated with sensitive antibiotics for 6 weeks after the operation， and the patient was cured during the follow-up of half a year after the operation. ConclusionFor middle-aged and elderly patients with clinical manifestations of acute severe low back pain or lower extremity pain， the possibility of spinal infection should be considered when routine laboratory and imaging examinations suggest lumbar degenerative diseases.

Characteristics of interbody bone graft fusion after transforaminal lumbar interbody fusion according to intervertebral space division.

Background: According to intervertebral space division, the characteristics of interbody bone graft fusion after transforaminal lumbar interbody fusion (TLIF) were assessed via computed tomography (CT) scan to provide a theoretical basis for selecting the bone grafting site of interbody fusion. Methods: The medical records of 57 patients with lumbar spinal stenosis and disc herniation treated with TLIF were analysed retrospectively. In total, 57 segments received lumbar interbody fusion. A thin-layer CT scan was performed to evaluate fusion in each zone of the fusion space. Results: The fusion rates were 57.89% (n = 33) in the anterior cage zone, 73.68% (n = 42) in the posterior cage zone, 66.67% (n = 38) in the decompression zone, 26.32% (n = 15) in the contralateral decompression zone and 94.74% (n = 54) in the inner cage zone. There were significant differences among the fusion rates of the five zones (P < 0.001). Further pairwise comparison revealed that the fusion rates in the inner cage significantly differed from the anterior and posterior cages and decompression and contralateral decompression zones (P = 0.001, 0.002, 0.001 and 0.001, respectively). Conclusion: We think the central cage zone (i.e., inner cage) should be the focus of bone grafting. Although there is small volume of bone graft on the posterior cage zone, the fusion rate is relatively high, only secondary to the inner cage zone. The fusion rate is of the contralateral decompression zone is lower although there is a bone graft.

Is Anterior Trans-Intervertebral Space Decompression Important in Treating Cervical Spondylosis with Severe Intervertebral Space Narrowing? A Retrospective Cohort Study.

OBJECTIVE: To evaluate the clinical efficacy and practicality of anterior trans-intervertebral space decompression and fusion (ATIDF) by comparing radiological and clinical outcomes between ATIDF and traditional anterior cervical corpectomy and fusion (ACCF) in cervical spondylosis patients with severe disc space narrowing. METHODS: Seventy-one cervical spondylosis patients with severe disc space narrowing underwent anterior cervical spine surgery were included in this retrospective study. Thirty-seven patients underwent ATIDF and 34 patients underwent ACCF. The neck disability index (NDI), Japan Orthopaedic Association (JOA) score and the Hirabayashi improvement rate were used to evaluate patient neurological status. Cervical sagittal alignment (C2-C7 Cobb angle), surgical segment sagittal alignment (Cobb angle of surgical segment) and disc space height were also compared between the two groups. RESULTS: There were 39 males and 32 females; mean age was 63.72 ± 6.36 years (range, 39-81 years). Mean follow-up was 22.4 months (range, 6-45 months). All patients achieved an adequate neurological improvement. There were no significant differences in NDI, JOA scores and Hirabayashi improvement rate between the two groups. The change of C2-7 Cobb angle and surgical segment Cobb angle were both greater in the ATIDF group. The average intervertebral height ratio of the patients in the ATIDF group increased significantly after surgery (0.38 ± 0.17 before surgery to 1.13 ± 0.32 after surgery, P < 0.01). The overall complication rate was lower in the ATIDF group than the ACCF group (35.14% and 44.12%). At 6 months follow-up, three patients in the ACCF group presented with subsidence of the titanium mesh cage. CONCLUSION: ATIDF is an effective technique for treating cervical spondylosis with severe disc space narrowing; it can achieve adequate decompression and improve sagittal alignment while avoiding and reducing the implant-related complications inherent to traditional ACCF.

[Current understanding of intervertebral space height in anterior cervical fusion].

Anterior cervical fusion surgery is the first choice for spine surgeons in the treatment of cervical spine diseases. It has significant effects in treating cervical degenerative diseases, trauma and tumors and other cervical diseases. In anterior cervical fusion, it is necessary to use a distractor to properly distract the intervertebral space, so as to fully expose and relieve the compressive factors, restore the physiological height, curvature and stability of the lesion segment, and achieve the best surgical effect. However, there is currently no consensus on the standard distraction height for the intervertebral space during anterior cervical surgery. This article reviewsed the progress of intervertebral space height in anterior cervical fusion from three dimensions:the relationship between intervertebral space height and cervical disc degeneration mechanism, the selection of intervertebral space height during operation, the recovery of intervertebral space height and the postoperative effect, so as to provide theoretical basis and reference for spinal surgeons when performing intervertebral distraction during operation.

Influence of coronal-morphology of endplate and intervertebral space to cage subsidence and fusion following oblique lumbar interbody fusion.

BACKGROUND: Endplate morphology is considered to be one of the influencing factors of cage subsidence after lumbar interbody fusion (LIF). Previous radiographic evaluations on the endplate mostly used sagittal X-ray or MRI. However, there are few studies on the CT evaluation of the endplate and intervertebral space (IVS), especially the evaluation of coronal morphology and its influence on subsidence and fusion after LIF. We aimed to measure and classify the shapes of the endplate and IVS using coronal CT imaging and evaluate the radiographic and clinical outcomes of different shapes of the endplate/IVS following oblique lateral lumbar interbody fusion (OLIF). METHODS: A total of 137 patients (average age 59.1 years, including 75 males and 62 females) who underwent L4-5 OLIF combined with anterolateral fixation from June 2018 to June 2020 were included. The endplate concavity depth (ECD) was measured on the preoperative coronal CT image. According to ECD, the endplate was classified as flat (< 2 mm), shallow (2-4 mm), or deep (> 4 mm). The L4-5 IVS was further classified according to endplate type. The disc height (DH), DH changes, subsidence rate, fusion rate, and Oswestry Disability Index (ODI) in different endplate/IVS shapes were evaluated during 1-year follow up. RESULTS: The ECD of L4 inferior endplate (IEP) was significantly deeper than that of L5 superior endplate (SEP) (4.2 ± 1.1 vs 1.6 ± 0.8, P < 0.01). Four types of L4-5 IVS were identified: shallow-shallow (16, 11.7%), shallow-flat (45, 32.9%), deep-shallow (32, 23.4%), and deep-flat (44, 32.1%). A total of 45 (32.9%) cases of cage subsidence were observed. Only one (6.3%) subsidence event occurred in the shallow-shallow group, which was significantly lower than in the other three groups (19 shallow-flat, 6 deep-shallow, and 19 deep-flat) (P < 0.05). Meanwhile, the shallow-shallow group had the highest fusion rate (15, 93.8%) and the highest rate of reach minimal clinically important difference (MCID) ODI among the four types. For a single endplate, the shape of L4 IEP is the main influencing factor of the final interbody fusion rate, and the shallow shape L4 IEP facilitates fusion ( OR = 2.85, p = 0.03). On the other hand, the flat shape L5 SEP was the main risk factor to cage subsidence (OR = 4.36, p < 0.01). CONCLUSION: The L4-5 IVS is asymmetrical on coronal CT view and tends to be fornix-above and flat-down. The shallow-shallow IVS has the lowest subsidence rate and best fusion result, which is possibly because it has a relatively good degree in matching either the upper or lower interface of the cage and endplates. These findings provide a basis for the further improvements in the design of OLIF cages.

Cadaveric anatomy of the lumbar triangular safe zone of Kambin's in North West Indian population.

A three dimensional triangular space 'the Kambin's triangle (KT)' present on the dorsolateral aspect of the intervertebral disc, is considered to be a safe area for transforaminal approaches. It allows access to the exiting and traversing nerve roots, the thecal sac and to the intervertebral disc spaces. Our aim was to calculate the area of the triangle by measuring the height and base at all the intervertebral spaces bilaterally in the lumbar region in North West Indian cadavers and to assess the diameter of circle inscribed within this triangle which will correspond to the size of cannula inserted for the minimally invasive transforaminal approaches in this population. Five randomly chosen adult cadavers were used for this study. After clearing the area, the exiting nerve was identified. The height and base of the bony KTs (n=40) were measured with the help of digital Vernier's calliper (accuracy 0.02 mm) to calculate the area of the KT. There is a steady increase in the area of the bony KT reaching maximum at the level of L4-5 intervertebral space. Statistically there were no differences in the calculated areas between right and left side. The mean diameter of inscribed circle within the triangle also showed gradual increase from 5.82 mm at L1-2 level, reaching maximum value of 7.26 mm at L4-5 level on the right side while on the left side the values were 5.66 mm and 8.16 mm respectively. Careful anatomical consideration is of utmost importance in transforaminal approaches during surgical or interventional procedures in this region. Cannula having external diameter ranging 6-8 mm is recommended for any interventional approach through Kambin's space.

Effect of Changes in Postoperative Intervertebral Space Height on Clinical and Radiological Outcomes After Cervical Disc Replacement.

BACKGROUND: Narrowing of intervertebral space height (ISH) is an important pathological change in degenerative spinal disease, and ideal intraoperative distraction and postoperative intervertebral space maintenance is one of the most expectant goals pursued by spinal surgeons. The effect of postoperative ISH changing on the clinical and radiological outcomes after cervical disc replacement is not fully understood, however. METHODS: In this study, the height variation and general trend of postoperative ISH in all patients were analyzed. The patients were divided into 3 groups based on the change of postoperative intervertebral space height (ISH)-group A (ISH <2 mm), group B (ISH 2-4 mm), and group C (ISH >4mm)-and the clinical and radiographic results compared among the 3 groups. RESULTS: A total of 120 consecutive patients with symptomatic cervical disc disease were included in this study. The results showed that the mean ISH increased significantly from 0.729 mm before surgery to 1.143 mm at 1 week, then gradually decreased to 1.032 mm at 3 months, 0.980 mm at 6 months, 0.760 mm at one year, and 0.750 mm at the final follow-up. The average postoperative Neck Disability Index (NDI) was 19.73 ± 0.81, 13.74 ± 4.94, 17.19 ± 4.22, respectively, in the 3 groups at 1 year after surgery and the average range of motion (ROM) was 5.44° ± 3.85° in group A, 9.34° ± 4.38° in group B, and 6.51° ± 4.38° in group C. The mean diameter of the intervertebral foramen was 6.54 ± 1.86 mm in group A, 9.63 ± 2.38 mm in group B, and 9.31 ± 1.68 mm in group C. Degeneration at the superiorly adjacent disc level was observed in 13.51% patients in group A, 9.37% in group B, and 21.05% in group C. Degeneration at the inferiorly adjacent level was radiographically identified in 21.62% in group A, 14.06% in group B, and 26.32% in group C. CONCLUSIONS: This study revealed that cervical disc replacement cannot maintain the intervertebral disc height obtained immediately after surgery. There is no obvious correlation between the change in intervertebral space height and clinical efficacy in the early postoperative stage. Nonetheless, the intervertebral disc height may affect the NDI index 1 year after surgery. If the postoperative intervertebral space height change can be maintained at 2-4 mm at 1 year, satisfactory ROM, intervertebral foramen diameter, and relatively low adjacent segment degeneration may be obtained after cervical disc replacement.

[The correlation between the severity of uncovertebral joints degeneration and heterotopic ossification after single-level artificial cervical disc replacement].

Objective: To investigate the correlation between the severity of uncovertebral joints degeneration and heterotopic ossification (HO) after single-level artificial cervical disc replacement (ACDR). Methods: From January 2005 to January 2016, 70 patients who had undergone single-level ACDR in Peking University Third Hospital and had at least 5 years follow-up were included in this study. There were 35 males and 35 females with an average age of (42±8) years (range, 25-62 years). Cervical spine A-P X-rays were taken to assess the degeneration of uncovertebral joints and lateral X-rays were taken to assess the degeneration of intervertebral space. Cervical spine lateral and the flexion-extension X-rays at 5 years follow up were taken to assess HO. Degeneration of uncovertebral joints were evaluated by the classification system set-up in Peking University Third Hospital. Kellgren&Lawrence grading system was used to evaluate the degeneration of intervertebral space. HO was evaluated by the McAfee grading standards. The data were collected before surgery and at 5-years follow-up, then the correlation between degeneration of uncovertebral joints, degeneration of intervertebral space and HO was analyzed with Spearman non-parametric test. Results: The average follow-up time of 70 patients was (62.7±4.8) years (range, 52-74 months). There was a significant positive correlation between preoperative uncovertebral joints degeneration and HO after ACDR (r=0.585, P<0.01). There was a significant positive correlation between preoperative intervertebral space degeneration and HO (r=0.557, P<0.01). There was a significant positive correlation between preoperative intervertebral space degeneration and preoperative uncovertebral joints degeneration (r=0.727, P<0.01). Conclusion: There is a significant positive correlation between preoperative uncovertebral joints degeneration and HO after ACDR.

[Study on the correlation between the arc height of cervical endplate and osteophyte in posterior margin of intervertebral space].

OBJECTIVE: To study the correlation and clinical value of the arc height of upper and lower endplates, the height of intervertebral space and osteophyte of posterior edge of intervertebral space in patients with cervical spondylosis. METHODS: A total of 108 patients with cervical spondylosis who underwent cervical spondylosis surgery from September 2017 to September 2018 were included in the study. Including 48 males with an average age of 52 years (30 to 72) and 60 females with an average age of 54 years (37 to 79). Among them, C2,3 of 6 cases, C3,4 of 15 cases, C4,5 of 32 cases, C5,6 of 42 cases, C6,7 of 13 cases. X-ray films of cervical spine were taken before and after operation. The images were accessed by PACS (Picture Archiving and Communication Systems) system. The lower and upper endplate arc heights (L1, L2), intervertebral space height (L3), and posterior osteophyte width (L4) were measured. Spearman was used to analyze the correlation between them. RESULTS: L1 was negatively correlated with L4 (r=-0.34, P<0.05), L3 was negatively correlated with L4 (r=-0.36, P<0.05). L1 was positively correlated with L3 (r=0.38, P<0.05), L2 was positively correlated with L3 (r=0.48, P<0.05). There was no significant difference between L 1 and L2 (P>0.05), L2 and L4 (P>0.05). CONCLUSION: The arc height of the lower endplate is negatively correlated with the width of osteophyte in the posterior margin of the intervertebral space. The cervical degeneration degree can be determined by measuring the arc height of the lower endplate, which has guiding significance for the early prevention and treatment of cervical spondylosis.

The concordance rate of L3/4 intervertebral lumbar level estimated by palpation and ultrasonography in Japanese parturients.

Background: The accurate identification of an intervertebral lumbar level is essential to avoid neuraxial anesthesia and analgesia-related spinal cord injury. It has been shown that estimation of L3/4 intervertebral lumbar level based on the intercristal line determined by palpation (palpated L3/4) is often inaccurate. However; studies evaluating intervertebral lumbar level concordance based on palpation vs. ultrasonography were conducted in Western populations (i.e. in North America and/or Europe). Radiological studies suggest that the intercristal line intersects at a lower level of the spine in Japanese women than in Western women. Therefore, we hypothesized that differences exist in intervertebral levels based on the palpated intercristal line between Asian and Western women. Herein we present the results of the first study in Japan comparing the concordance rate of L3/4 intervertebral lumbar level estimated by palpation and ultrasonography in pregnant Japanese women.Study objective: The objective of this study was to evaluate the accuracy of palpated L3/4 in Japanese parturients assessed by ultrasonography (US).Design: A prospective, observer-blinded study.Setting: Labor and delivery room at the Kitasato University Hospital, Sagamihara, Kanagawa, Japan.Patients: Sixty-three term parturients underwent induction of labor and requested neuraxial labor analgesia.Interventions: With the patients in the sitting position, an attending anesthesiologist marked the intervertebral space estimated as L3/4 based on intercristal line with palpation. Another attending anesthesiologist who was blinded to the marker performed US to identify L3/4.Results: The overall agreement rate of palpated and US L3/4 was 69.8% (44/63). Palpated L3/4 was US L2/3 in 8/63 (12.7%) and US L4/5 in 11/63 (17.5%). In comparison with women with palpated L3/4 agreed with US L3/4, women with palpated L3/4 agreed with US L2/3 were more frequently multiparous (52 vs. 100%, p < .05) and women with palpated L3/4 identified as L4/5 were younger (36 ± 4 years vs. 33 ± 4 yrs, p < .05) and gained less weight during pregnancy (10 ± 4 kg vs. 7 ± 4 kg, p < .05). The patients whose palpated L3/4 were found to be US L2/3 were all multiparous.Conclusion: The accuracy rate of palpated L3/4 intervertebral lumbar level in pregnant women included in our study was 69.8%. Pregnancy-related weight gain, parity, and maternal age can all influence an estimation of L3/4 intervertebral lumbar level by palpation. In addition, we believe that this is the first study to analyze the correlation between maternal parity and interspace estimation by palpation in pregnant women.

Study on the correlation between the arc height of cervical endplate and osteophyte in posterior margin of intervertebral space / 中国骨伤

OBJECTIVE@#To study the correlation and clinical value of the arc height of upper and lower endplates, the height of intervertebral space and osteophyte of posterior edge of intervertebral space in patients with cervical spondylosis.@*METHODS@#A total of 108 patients with cervical spondylosis who underwent cervical spondylosis surgery from September 2017 to September 2018 were included in the study. Including 48 males with an average age of 52 years (30 to 72) and 60 females with an average age of 54 years (37 to 79). Among them, C of 6 cases, C of 15 cases, C of 32 cases, C of 42 cases, C of 13 cases. X-ray films of cervical spine were taken before and after operation. The images were accessed by PACS (Picture Archiving and Communication Systems) system. The lower and upper endplate arc heights (L, L), intervertebral space height (L), and posterior osteophyte width (L) were measured. Spearman was used to analyze the correlation between them.@*RESULTS@#L was negatively correlated with L (r=-0.34, 0.05), L and L (>0.05).@*CONCLUSION@#The arc height of the lower endplate is negatively correlated with the width of osteophyte in the posterior margin of the intervertebral space. The cervical degeneration degree can be determined by measuring the arc height of the lower endplate, which has guiding significance for the early prevention and treatment of cervical spondylosis.

Von mises stress on the influence of pelvic stability by precise sacral resection and clinical validation / 中国组织工程研究

BACKGROUND: Sacral resection has now become the accepted treatment of choice for malignant tumors of the sacrum. There are few biomechanical studies on whether fractures or sacroiliac joint spondylolisthesis will occur after simple sacral resection, and there is no consensus on whether the weight can be fully loaded after subtotal sacral resection and when to rebuild. OBJECTIVE: To contrast clinical research and analyze Von Mises stress to provide a credible theoretic basis about which level of sacrectomy without spinopelvic reconstruction is acceptable for pelvic stability through the biomechanical testing of intact pelvis and models of pelvis after subdivided sacrectomy. METHODS: (1) Biomechanical research: Six fresh normal adult human cadaveric L5-pelvis specimens were chosen. Compressive stress loaded on the specimens was increased by 200 N, until 1 000 N, at the speed of 1.4 mm/min. The change of Von Mises stress was measured to the same pelvic specimens on intact sacrum and groups of subdivided sacrectomy. The differences were compared between groups of data. (2) Clinical studies: Totally 15 patients diagnosed with high sacral tumor with tumor resection between January 2012 and June 2019 were enrolled, including 6 males and 9 females with an average age of 46.40±14.94 years. According to preoperative MRI examination, the extent of sacral involvement was determined, and the size of sacral resection was determined. No reconstruction was performed after operation. Postoperative function and complications were recorded. RESULTS AND CONCLUSION: (1) Biomechanical research: With the growth of the sacrum resection plane, Von Mises stress had different increases at different test points, particularly by 1/4 S1 to 1/2 S1, which were apparently different with that in other groups (P < 0.05). Compared with group 2/3 S2 and group 1/3 S2, the change of Von Mises stress at point A in group S1-2 was not statistically significant. (2) Clinical results: Among the 15 patients, 4 patients retained the intact S1 vertebral body during the operation (resection of the S1-S2 intervertebral space, as in the biomechanics experiment S1-2 group); sacrum was resected in 3 patients as the group 2/3 S2 during the operation, and sacrum was resected in 2 patients during the operation as group 1/3 S2; and the S1 and S2 vertebrae were kept intact in 6 patients (as resection in the S2-3 group). The mean score of musculoskeletal tumor society was 25.27±3.79. All patients were able to walk, nine without walking aids, six with walking aids, one of them developed residual sacral fracture. (3) With the growth of the sacrum resection plane, Von Mises stress at residual sacrum rapidly rose. When the sacrum was resected by S1-S2 intervertebral space, the stability of the pelvic ring was acceptable without spinopelvic reconstruction.