Cranial Levels Research Articles

Bipolar hybrid posterior instrumentation tecnique for the correction of Scheuermann's kyphosis.

Scheuermann´s kyphosis (SK) is the most common cause of painful and progressive structural hyperkyphosis in adolescents. Surgical treatment should be considered in cases of refractory pain or progressive deformities. We present the clinical and radiological results obtained using a bipolar, hybrid posterior instrumentation tecnique. We analysed 12 males and 6 females, with mean age of 15.8years. Minimum follow-up was 2years. We used transverse process hooks at the cranial level and polyaxial screws for the remaining levels. We did not instrument the periapical segment. We used the sagittal stable vertebra (SSV) as the lower instrumented vertebra (LIV) in most cases, the "barely touched SSV" if the above disc space is lordotic. The mean preoperative kyphosis was 73.6º, mean postoperative kyphosis 44.7º, and mean correction of 28.9º (p = 0.0002). The mean reduction in lumbar lordosis (LL) was 8.9º (p = 0.0018). There were no significant differences in the spinopelvic parameters or sagittal balance. The mean number of instrumented levels was 8.9. Type II osteotomies were necessary in only three patients. Three patients had a cranial sagittal angle greater than 10°, all of them asymptomatic. Postoperatively, all patients had VAS scores less than 2 and SRS-22 scores greater than 4. Hybrid bipolar posterior instrumentation offers adequate curve correction, less operative time, implant density, bleeding, material protrusion and risk of spinal cord injury, leaving a large periapical bed for graft supply. We propose to measure the flexibility of the curve in MRI. In flexible curves (those that correct at least 20% in the supine decubitus position), wide facetectomies offer adequate correction of the deformity.

Monocentric Retrospective Analysis of Clinical Outcomes, Complications, and Adjacent Segment Disease in 507 Patients Undergoing Anterior Cervical Discectomy and Fusion for Degenerative Cervical Myelopathy

BackgroundDegenerative Cervical Myelopathy (DCM) is a leading cause of non-traumatic spinal cord injury. Surgery aims to arrest neurological decline and improve conditions, but controversies surround risks and benefits in elderly patients, outcomes in mild myelopathy, and the risk of adjacent segment disease (ASD). MethodsRetrospective data of patients who underwent ACDF for DCM in our hospital were collected. Patients were stratified by preoperative mJOA (mild, moderate, severe) and age (Under 70, Over 70). Clinical outcomes, complications, and ASD rate were analyzed. We evaluated the relationship between mJOA recovery rate and the risk of complications and various preoperative parameters. Results507 consecutive patients were included in the study, with a mean follow-up of 43.52 months (12-71). Improvement in all outcome variables was observed in mild, moderate and severe myelopathy categories, with elderly patients showing a lower improvement. Except for age, no other variable correlated with mJOA recovery rate. We observed 45 complications (11.1% of patients), with 14 in the U70 group and 31 in the O70 group (p-value<0.001). Age, Charlson Comorbidity index and ASA score were found to be predictors of complications. Fourteen patients (2.8% of total), mean age 54.2, developed radiological and clinical ASD. Most had cranial-level ASD with Pfirmann grade >= 2 before index surgery. ConclusionsMost myelopathic patients improve after ACDF. Elderly patients show a lower improvement and higher complication rates than younger counterparts. ASD rates are low, and younger patients with preexisting cranial level alterations are more susceptible.

Risk factors for poor neurological recovery after anterior cervical discectomy and fusion: imaging characteristics

BackgroundPoor neurological recovery in patients after anterior cervical discectomy and fusion has been frequently reported; however, no study has analyzed the preoperative imaging characteristics of patients to investigate the factors affecting surgical prognosis. The purpose of this study was to investigate the factors that affect the preoperative imaging characteristics of patients and their influence on poor neurologic recovery after anterior cervical discectomy and fusion.MethodsWe retrospectively analyzed the clinical data of 89 patients who met the criteria for anterior cervical discectomy and fusion for the treatment of single-level cervical spondylotic myelopathy and evaluated the patients’ neurological recovery based on the recovery rate of the Japanese Orthopaedic Association (JOA) scores at the time of the final follow-up visit. Patients were categorized into the “good” and “poor” groups based on the JOA recovery rates of ≥ 50% and < 50%, respectively. Clinical information (age, gender, body mass index, duration of symptoms, preoperative JOA score, and JOA score at the final follow-up) and imaging characteristics (cervical kyphosis, cervical instability, ossification of the posterior longitudinal ligament (OPLL), calcification of herniated intervertebral discs, increased signal intensity (ISI) of the spinal cord on T2-weighted imaging (T2WI), and degree of degeneration of the discs adjacent to the fused levels (cranial and caudal) were collected from the patients. Univariate and binary logistic regression analyses were performed to identify risk factors for poor neurologic recovery.ResultsThe mean age of the patients was 52.56 ± 11.18 years, and the mean follow-up was 26.89 ± 11.14 months. Twenty patients (22.5%) had poor neurological recovery. Univariate analysis showed that significant predictors of poor neurological recovery were age (p = 0.019), concomitant OPLL (p = 0.019), concomitant calcification of herniated intervertebral discs (p = 0.019), ISI of the spinal cord on T2WI (p <0.05), a high grade of degeneration of the discs of the cranial neighboring levels (p <0.05), and a high grade of discs of the caudal neighboring levels (p <0.05). Binary logistic regression analysis showed that ISI of the spinal cord on T2WI (p = 0.001 OR = 24.947) and high degree of degeneration of adjacent discs on the cranial side (p = 0.040 OR = 6.260) were independent risk factors for poor neurological prognosis.ConclusionISI of the spinal cord on T2WI and high degree of cranial adjacent disc degeneration are independent risk factors for poor neurological recovery after anterior cervical discectomy and fusion. A comprehensive analysis of the patients’ preoperative imaging characteristics can help in the development of surgical protocols and the management of patients’ surgical expectations.

Perioperative and safety outcomes following tissue-sparing posterior cervical fusion to revise a pseudarthrosis: A multicenter retrospective review of 150 cases.

Posterior cervical fusion (PCF) with lateral mass screws is a favorable treatment option to revise a symptomatic pseudarthrosis due to reliable rates of arthrodesis; however, this technique introduces elevated risk for wound infection and hospital readmission. A tissue-sparing PCF approach involving facet fixation instrumentation reduces the rates of postoperative complications while stabilizing the symptomatic level to achieve arthrodesis; however, these outcomes have been limited to small study cohorts from individual surgeons commonly with mixed indications for treatment. One hundred and fifty cases were identified from a retrospective chart review performed by seven surgeons across six sites in the United States. All cases involved PCF revision for a pseudarthrosis at one or more levels from C3 to C7 following anterior cervical discectomy and fusion (ACDF). PCF was performed using a tissue-sparing technique with facet instrumentation. Cases involving additional supplemental fixation such as lateral mass screws, rods, wires, or other hardware were excluded. Demographics, operative notes, postoperative complications, hospital readmission, and subsequent surgical interventions were summarized as an entire cohort and according to the following risk factors: age, sex, number of levels revised, body mass index (BMI), and history of nicotine use. The average age of patients at the time of PCF revision was 55 ± 11 years and 63% were female. The average BMI was 29 ± 6 kg/m2 and 19% reported a history of nicotine use. Postoperative follow-up visits were available with a median of 68 days (interquartile range = 41-209 days) from revision PCF. There were 91 1-level, 49 2-level, 8 3-level, and 2 4±-level PCF revision cases. The mean operative duration was 52 ± 3 min with an estimated blood loss of 14 ± 1.5cc. Participants were discharged an average of 1 ± 0.05 days following surgery. Multilevel treatment resulted in longer procedure times (single = 45 min, multi = 59 min, P = 0.01) but did not impact estimated blood loss (P = 0.94). Total nights in the hospital increased by 0.2 nights with multilevel treatment (P = 0.01). Sex, age, nicotine history, and BMI had no effect on recorded perioperative outcomes. There was one instance of rehospitalization due to deep-vein thrombosis, one instance of persistent pseudarthrosis at the revised level treated with ACDF, and four instances of adjacent segment disease. In patients initially treated with multilevel ACDF, revisions occurred most commonly on the caudal level (48% of revised levels), followed by the cranial (43%), and least often in the middle level (9%). This chart review of perioperative and safety outcomes provides evidence in support of tissue-sparing PCF with facet instrumentation as a treatment for symptomatic pseudarthrosis after ACDF. The most common locations requiring revision were the caudal and cranial levels. Operative duration and estimated blood loss were favorable when compared to open alternatives. There were no instances of postoperative wound infection, and the majority of patients were discharged the day following surgery.

Biomechanical assessment of different transforaminal lumbar interbody fusion constructs in normal and osteoporotic condition: a finite element analysis

BACKGROUND CONTEXTWith the aging population, osteoporosis, which leads to poor fusion, has become a common challenge for lumbar surgery. In addition, most people with osteoporosis are elderly individuals with poor surgical tolerance, and poor bone quality can also weaken the stability of internal fixation. PURPOSEThis study compared the fixation strength of the bilateral traditional trajectory screw structure (TT-TT), the bilateral cortical bone trajectory screw structure (CBT-CBT), and the hybrid CBT-TT (CBT screws at the cranial level and TT screws at the caudal level) structure under different bone mineral density conditions. STUDY DESIGNA finite element (FE) analysis study. METHODSAbove all, we established a healthy adult lumbar spine model. Second, under normal and osteoporotic conditions, three transforaminal lumbar interbody fusion (TLIF) models were established: bilateral traditional trajectory (TT-TT) screw fixation, bilateral cortical bone trajectory (CBT-CBT) screw fixation, and hybrid cortical bone trajectory screw and traditional trajectory screw (CBT-TT) fixation. Finally, a 500-N compression load with a torque of 10 N/m was applied to simulate flexion, extension, lateral bending, and axial rotation. We compared the range of motion (ROM), adjacent disc stress, cage stress, and posterior fixation stress of the different fusion models. RESULTSUnder different bone mineral density conditions, the range of motion of the fusion segment was significantly reduced. Compared to normal bone conditions, the ROM of the L4–L5 segment, the stress of the adjacent intervertebral disc, the surface stress of the cage, and the maximum stress of the posterior fixation system were all increased in osteoporosis. Under most loads, the ROM and surface stress of the cage and the maximum stress of the posterior fixation system of the TT-TT structure are the lowest under normal bone mineral density conditions. However, under osteoporotic conditions, the fixation strength of the CBT-CBT and CBT-TT structures are higher than that of the TT-TT structures under certain load conditions. At the same time, the surface stress of the intervertebral fusion cage and the maximum stress of the posterior fixation system for the two structures are lower than those of the TT-TT structure. CONCLUSIONUnder normal bone mineral density conditions, transforaminal lumbar interbody fusion combined with TT-TT fixation provides the best biomechanictability. However, under osteoporotic conditions, CBT-CBT and CBT-TT structures have higher fixed strength compared to TT-TT structures. The hybrid CBT-TT structure exhibits advantages in minimal trauma and fixation strength. Therefore, this seems to be an alternative fixation method for patients with osteoporosis and degenerative spinal diseases. CLINICAL SIGNIFICANCEThis study provides biomechanical support for the clinical application of hybrid CBT-TT structure for osteoporotic patients undergoing TLIF surgery.

Influence of cervical total disc replacement on motion in the target and adjacent segments

Background ContextThe motion limitation after cervical discectomy and fusion alters the spine´s kinematics. Unphysiological strains may be the result and possible explanation for adjacent segment degeneration. Alterations to cervical kinematics due to cervical total disc replacement (TDR), especially two-level, are still underinvestigated. PurposeTo investigate cervical motion including coupled motions after one-level and two-level TDR in the treated and also the adjacent segments. Study DesignAn in-vitro study using pure moment loading of human donor spines. MethodsSeven fresh frozen human cervical spine specimens (C4-T1, median age 46 with range 19-60 years, four female) were included in this study. Specimens were tested in the intact condition first, followed by one-level TDR at C5-6 which was subsequently extended one level further caudal (C5-7). Each specimen was quasistatically loaded with pure moments up to 1.5 Nm in flexion/extension (FE), lateral bending (LB) and axial rotation (AR) in a universal spine tester for 3.5 cycles at 1 °/s. During the tests three dimensional motion tracking was performed for each vertebral body individually. From that the primary and coupled ROM of each spinal level during the third full cycle of motion were evaluated. Non-parametric statistical analysis was performed using a Friedman-test and post-hoc correction with Dunn-Bonferroni-tests (p < 0.05). Ethics approval was obtained in advance. ResultsIn FE, one-level TDR (C5-6) moderately increased primary FE in all four segments, but only significantly at the cranial adjacent level C4-5. Additional TDR at C6-7 further increased the ROM at the target segment without much influence on the other levels. Increasing implant height at C6-7 partially counteracted the increased FE. Coupled motions were minimal in all test conditions at all levels.In LB, coupled AR was observed in all test conditions at all levels. One-level TDR decreased primary LB at the target segment C5-6 significantly, without much influence on the other levels. Extending TDR to C6-7 decreased ROM in the target segment but without gaining statistical significance. Increasing implant height at C6-7 further decreased primary LB at the target segment, still without significance. Notably, coupled AR was significantly decreased at the cranial adjacent segment C4-5 compared to the intact condition.In AR, coupled LB was observed in all test conditions at the levels C4-5, C5-6 and C6-7, while the transition level to the thoracic spine C7-T1 showed only little coupled LB. Both one-level and two-level TDR showed little influence on primary AR or coupled motions at any level. Only after increasing implant height at C6-7 was the motion of the caudally adjacent level C7-T1 significantly altered. ConclusionEvaluating primary FE, LB and AR together with the associated coupled motions revealed widespread influence of cervical TDR not only on the motion of the treated level but also at the adjacent segments. The influence of two-level TDR is more widespread and involves more levels than one-level TDR. Clinical SignificanceThe prevention of unphysiological strains due to altered kinematics after cervical fusion, which could possibly explain adjacent segment degeneration, were a driving factor in the development of TDR. These experimental findings suggest cervical TDR influences the whole cervical spine, not only the treated segment. The effect becomes more extensive, involving more levels and motion directions, after two-level than after one-level TDR.

The usefulness of S100ß protein and fractalkin in predicting traumatic brain injury in pediatric patients with minor head trauma

Aims: In this study it was aimed to demonstrate the effectiveness of S100B protein levels which are biomarkers related to central nervous system, and fractalkin levels, which are known to play a role in inflammation processes in prediction trauma induced brain damage. Methods: Patient aged 2 to 18 years who came to the emergency department due to minor head trauma and underwent brain ct were included in our study. It was investigated whether there was a relationship between the two groups, according to the causes of trauma, symptoms at presentation and the level of serum s100b and FCN according to the lesions detected in CCT. Results: The other symptoms including Vomiting, retrograde amnesia, loss of consciousness, confusion, post traumatic amnesia is significantly higher in patients with brain lesions (p&lt;0,05). Patients with lesions on BCT have significantly low Glassgow coma score. (p&lt;0,05). Patients with lesions on BCT have a significantly high S100B and FKN levels. (p&lt;0,05). S100B area under the curve (CUA) 0.700 sensivity is 55%, spesificity is 87.5%. FKN CUA 0,785, sensitivity is 62.5% specifisity is 85%. Conclusions: As a result, the child patients with BCT lesions from minor cranial trauma levels for S100B and FKN levels are significantly higher and can be a criteria for BCT usage in emergency medicine.

Utility of modified pancreaticoduodenectomy (Hi-cut PD) for middle-third cholangiocarcinoma: an alternative to hepatopancreaticoduodenectomy

BackgroundThe standard procedure for middle-third cholangiocarcinoma (MCC) is pancreaticoduodenectomy (PD); hepatopancreaticoduodenectomy (HPD) is often performed despite its high risk. There is no clear selection guidance for these procedures. MethodsPatients with MCC who underwent HPD or PD were retrospectively evaluated. The conventional PD was modified (mPD) to transect the bile duct beyond or close to the cranial level of the portal bifurcation. ResultsThe mPD group (n = 55) was characterized by older age, shorter operation time, less blood loss, and less frequent complications than were observed in the HPD group (n = 34). The median grossly tumor-free margin of the proximal bile duct (GM) was 13 mm vs 20 mm (P = 0.006). Overall survival did not differ significantly between groups (48% vs 53% at 5 years, P = 0.399). Multivariate analysis identified positive surgical margin as a sole independent prognostic factor (hazard ratio, 1.89; P = 0.043), which was statistically associated with GM length. Five-year survival for mPD patients with GM ≥15 mm was significantly better than that for those who had GM <15 mm (69% vs 33%, P = 0.011) and comparable to that of HPD patients (53%, P = 0.450). ConclusionThe mPD may be recommended in patients with MCC, provided that GM ≥15 mm is expected from the preoperative radiological imaging. Otherwise, HPD should be considered.

Degenerative L4-L5 spondylolisthesis and stenosis surgery: does over-level flavectomy technique influence clinical outcomes and rates of cranial adjacent segment disease?

One of the most dreaded long-term complications related to L4-L5 lumbar arthrodesis is the onset of adjacent segment disease, which most frequently occurs at the cranial level. Few studies have compared the rates of cranial adjacent segment disease (CASD) in patients undergoing lumbar fusion associated with total laminectomy at the same level with those undergoing partial laminectomy. No study has examined the role of selective over-level flavectomy (OLF; i.e., L3-L4). A total of 299 patients undergoing posterolateral arthrodesis (PLA) for L4-L5 degenerative spondylolisthesis were retrospectively analyzed with a 5-year follow-up. 148 patients underwent PLA + L4-L5 flavectomy + L4 partial laminectomy (control group), while 151 underwent PLA + L4-L5 flavectomy + total L4 laminectomy + L3-L4 flavectomy (OLF group). Rates of reoperations due to CASD were examined utilizing Cox proportional hazard models, while clinical improvement at follow-up (measured in ODI) was analyzed using generalized linear models (GLMs). Adjustments for potential confounders were made (grade of lumbar lordosis, age, sex, BMI, intervertebral disc degeneration, and presurgical cranial spinal stenosis). At 5 years from the operation, 16 patients (10.8%) in the control group had undergone revision surgery for CASD compared to 5 patients (3.3%) in the OLF group (p = 0.013). Survival analysis and GLM demonstrated that the OLF group had a significantly lower incidence of CASD and presented more favorable clinical outcome. There were no differences in the rate of discal degeneration or the onset of Meyerding's grade I degenerative spondylolisthesis at the adjacent segment. BMI was the only other significant predictor of ODI improvement and of the incidence of CASD. In patients with L4-L5 degenerative spondylolisthesis and stenosis, the OLF technique may lower rates of CASD and improve clinical outcomes by preventing cranial spinal stenosis without increasing iatrogenic instability or accelerating intervertebral disc degenerative changes.

Minimally invasive LLIF surgery to decrease the occurrence of adjacent-segment disease compared to conventional open TLIF.

Lateral lumbar interbody fusion with percutaneous pedicle screw fixation (Mis-LLIF) can establish indirect decompression by lifting the vertebra with a large intervertebral cage, which causes less damage to the posterior elements. Thus, Mis-LLIF is expected to reduce the incidence of adjacent segment disease (ASD). The aim of the study was to compare the occurrence of ASD between Mis-LLIF and conventional open transforaminal interbody fusion (TLIF). A total of 156 patients (TLIF group = 88, Mis-LLIF group = 68) who underwent single-level lumbar interbody fusion (L2/3, L3/4, or L4/5) at a single institution between 2003 and 2018 with minimum 2-year follow-up were retrospectively reviewed. The incidence of symptomatic ASD requiring reoperation (S-ASD) and radiological adjacent segment degeneration (R-ASD) 2years postoperatively were investigated between 51 paired patients from both groups who were propensity score (PS) matched by demographic and baseline clinical data. The effect of characteristics arising from differences in surgical methods between Mis-LLIF and TLIF, such as the amount of distraction of the index fused level (∆H), on S-ASD and R-ASD was also examined. There were no significant differences in the incidence of S-ASD between the Mis-LLIF and TLIF groups (adjusted OR 1.3; 95% CI 0.41-3.9). There was no significant difference in the incidence of R-ASD between the Mis-LLIF and TLIF groups both at the cranial (adjusted OR 1.0; 95% CI 0.22-4.5) and caudal level (adjusted OR 1.5; 95% CI 0.44-5.3). On the other hand, ∆H was significantly higher in the Mis-LLIF group than in the TLIF group (3.6mm vs. 1.7mm, respectively, P < 0.0001), and was extracted as a significant independent risk factor for S-ASD (adjusted HR 2.7; 95% CI 1.1-6.3) and R-ASD at the cranial side (adjusted HR 6.4; 95% CI 1.7-24) in multivariable analysis with PS adjustment. The incidence of R-ASD or S-ASD was not significantly reduced in the Mis-LLIF group compared to the TLIF group, with greater ∆H potentially being a contributing factor. Using a thin cage in both TLIF and Mis-LLIF may decrease the occurrence of ASD.

Subsequent meningiomas in survivors of childhood cancer: A report from the Childhood Cancer Survivor Study (CCSS).

10058 Background: Meningiomas are the most common subsequent central nervous system tumor among aging survivors of childhood cancer, yet incidence across the lifespan, occurrence of multiple meningiomas, and risk for mortality are not established. Methods: Meningiomas were identified by self-report and validated with pathology/medical records. Twenty-year cumulative incidence of meningioma (95% confidence interval) was estimated and multivariable models assessed demographic- and treatment-related meningioma risk factors. Results: Among 24,902 5-year survivors of childhood cancer diagnosed 1970-1999, we identified 472 survivors with 710 meningiomas, 145 (20.4%) of which were WHO grade 2/3. Among survivors with meningioma, 137 (28%) had ≥2 meningiomas, and 80 (16%) met criteria for meningiomatosis. The median latency from childhood cancer to first meningioma diagnosis was 26.2 years (range 5.6-48.2), and the median time from first to second meningioma (among those without meningiomatosis) was 1.4 years (range 0-30.2 years). The twenty-year cumulative incidence did not significantly decrease between survivors diagnosed in the 1970s (0.58, 95% CI 0.41-0.79) and the 1990s (0.42, 95% CI 0.32-0.55). In multivariable analysis, female sex (HR 1.52, 95% CI 1.21-1.91) and all cranial radiotherapy dose levels ( &gt; 0-30Gy, HR 57.0, 95% CI 7.93-419.60; 30.1-50 Gy, HR 228.90, 95% CI 30.89-1695.99; &gt; 50 Gy, HR 113.29, 95% CI 15.09-850.34) were associated with increased meningioma risk, while older age at diagnosis (10-14 years, HR 0.60, 95% CI 0.44-0.82; 15-20 years, HR 0.35, 95% CI 0.22-0.55) was associated with reduced meningioma risk. Among 71 deaths in survivors with meningioma, the most prevalent cause of death was meningioma (N = 25, 35.2%). The 5-year all-cause mortality from first meningioma diagnosis was 4.20% (95% CI: 2.44-5.96%). Conclusions: In conclusion, cranial radiation, younger diagnostic age and female sex were identified as independent meningioma risk factors in, to our knowledge, the largest study to date. The risk for meningioma-associated mortality argues for assertive meningioma surveillance and treatment in this population.

Secondary blast injury: radiological characteristics of shrapnel injuries in children.

The aim of this study is to examine the radiological images of child victims suffering from secondary blast injuries, to reveal organ-based injury patterns and their interrelationships, and to record mortality rates that may develop due to injured systems. A total of 65 patients with secondary blast injury due to bomb explosion were included in the study. Injury findings due to shrapnel in radiologic images of the patients were examined. Injured systems and types of injuries were recorded. The most common injuries were intra-abdominal injuries (63%) and fractures (58.5%). Lung injury was observed in 4 (9.8%) of 41 patients with intra-abdominal injury, while 37 (90.2%) did not, and this was statistically significant (p = 0.003). The most common intra-abdominal organ injury was a small bowel injury in 23 (35.4%) patients. The coexistence of small bowel injury and large bowel injury was present in 8 patients (34.8%), and it was statistically significant (p = 0.019). A total of 14 (21.5%) of the patients died. There was no significant relationship between mortality and gender (p = 319). Brain damage was present in 10 (71.4%) of the 14 (21.5%) patients who died, which was statistically significant (p < 0.001). Our results showed that the most common injuries were intra-abdominal injuries, damage to different organs could occur at the same time, and deaths were especially associated with brain injuries. For this reason, it should not be forgotten that CT scans will have an important place in the triage of the patient, especially in victims with shrapnel at the abdominal and cranial levels in radiography examinations.

Aspects of vertebral column resection in patients with rigid kyphotic and kyphoscoliotic deformities of different genesis of the thoracolumbar spine: multicenter retrospective observational cohort study

BACKGROUND: Vertebral column resection (VCR) as a type of spinal osteotomy is characterized by maximum possibilities of three-dimensional correction of various etiologies: congenital, post-tuberculous, iatrogenic (after other interventions on the spine), degenerative, and vertebral spondyloptosis caused by Kmmels disease, and primary, and metastatic tumor lesions of the spine. Nowadays, the use of single-level VCR is far beyond its initial purpose.&#x0D; OBJECTIVE: The study aimed to compare features of VCR for rigid deformities of various etiologies and management of erythrocyte blood products in the perioperative period.&#x0D; MATERIALS AND METHODS: A multicenter retrospective observational cohort study analyzed data from 53 adult (aged 18 years) patients with kyphotic and kyphoscoliotic deformities of the thoracic and lumbar spine, distributed into four comparison groups according to the deformity genesis, namely, impaired spinal development, traumatic genesis, degenerative or idiopathic, and neoplasms of the vertebral bodies. The characteristics of VCR in these patients were compared.&#x0D; RESULTS: The surgery duration was longer in VCR for spinal neoplasms (p 0.05) than for high-energy burst compression fractures of vertebral bodies and scoliotic deformities (grade IV). On average, this group also had the most cranial osteotomy level among the study groups. VCR for idiopathic scoliotic deformities is characterized by a larger intraoperative blood loss volume than other nosologies, and the differences were statistically significant. In male patients of this group, the hemoglobin level on day 1 after surgery was statistically significantly lower than in those who underwent VCR for compression fractures of the vertebral bodies or impaired vertebral development. During resection of the vertebral column for burst compression fractures of the vertebral bodies, the fixation length was less (p 0.05), with a similar intervention for developmental anomalies, deformities of postoperative genesis, and grade IV idiopathic scoliosis. VCR for grade IV idiopathic scoliosis requires a larger (p 0.05) volume of the reinfused autologous blood than for intervention for acute traumatic pathologies (burst compression fractures of the vertebral bodies).&#x0D; CONCLUSION: The versatility of clinical tasks for which resection of the spinal column can be performed using the VCR technique also determines the significant heterogeneity of the patients who undergo such treatment. Knowledge of the interventions in various nosologies is very useful in vertebrological practice.

Biomechanical evaluation of a novel biomimetic artificial intervertebral disc in canine cervical cadaveric spines.

Cervical disc replacement (CDR) aims to restore motion of the treated level to reduce the risk of adjacent segment disease (ASD) compared with spinal fusion. However, first-generation articulating devices are unable to mimic the complex deformation kinematics of a natural disc. Thus, a biomimetic artificial intervertebral CDR (bioAID), containing a hydroxyethylmethacrylate (HEMA)-sodium methacrylate (NaMA) hydrogel core representing the nucleus pulposus, an ultra-high-molecular-weight-polyethylene fiber jacket as annulus fibrosus, and titanium endplates with pins for primary mechanical fixation, was developed. To assess the initial biomechanical effect of the bioAID on the kinematic behavior of the canine spine, an ex vivo biomechanical study in 6-degrees-of-freedom was performed. A canine cadaveric biomechanical study. Six cadaveric canine specimens (C3-C6) were tested in flexion-extension (FE), lateral bending (LB) axial rotation (AR) using a spine tester in three conditions: intact, after C4-C5 disc replacement with bioAID, and after C4-C5 interbody fusion. A hybrid protocol was used where first the intact spines were subjected to a pure moment of ±1Nm, whereafter the treated spines were subjected to the full range of motion (ROM) of the intact condition. 3D segmental motions at all levels were measured while recording the reaction torsion. Biomechanical parameters studied included ROM, neutral zone (NZ), and intradiscal pressure (IDP) at the adjacent cranial level (C3-C4). The bioAID retained the sigmoid shape of the moment-rotation curves with a NZ similar to the intact condition in LB and FE. Additionally, the normalized ROMs at the bioAID-treated level were statistically equivalent to intact during FE and AR while slightly decreased in LB. At the two adjacent levels, ROMs showed similar values for the intact compared to the bioAID for FE and AR and an increase in LB. In contrast, levels adjacent to the fused segment showed an increased motion in FE and LB as compensation for the loss of motion at the treated level. The IDP at the adjacent C3-C4 level after implantation of bioAID was close to intact values. After fusion, increased IDP was found compared with intact but did not reach statistical significance. This study indicates that the bioAID can mimic the kinematic behavior of the replaced intervertebral disc and preserves that for the adjacent levels better than fusion. As a result, CDR using the novel bioAID is a promising alternative treatment for replacing severely degenerated intervertebral discs.

Morphometric MRI analysis of lumbar spine intervertebral foramen

The article presents morphometric MRI-analysis of the lumbar intervertebral foramen for anatomical study of the size of Kambin safety triangle and the vulnerability of the exiting spinal nerve during transforaminal interventions. 200 discs were studied in 50 patients after transforaminal endoscopic intervention. Standard DICOM image viewing program for MRI in T1 WI and T2 WI modes was used for the measurement. The most distant location of the exiting spinal nerve from the intervertebral disc was observed at the level of L5S1 vertebrae (9.82 mm, 0.95CI (9,53 10,10), p&lt;0.05). The narrowest safety triangle turned out to be at the level of L2‑L5 vertebrae, where the distance did not differ statistically (1.97–2.28 mm, p&gt; 0.05). A similar pattern was revealed for the distance between the exiting root and the intervertebral joint. The greatest angle between the exiting spinal nerve and the disc plane was found at the level of L5S1 (134.68 °, 0.95CI (132.39 136.97), p&lt;0.001). The angle was close to a straight one at the other levels. The exiting root located dorsal to the disc plane at the cranial levels (L2L3, L3L4) in all cases, in contrast to L5S1 level, where it always located ventrally. Thus, the greatest narrowness of the Kambin safety triangle was revealed in the intervertebral foramen of the cranial lumbar segments (L2L3, L3L4). Transforaminal interventions require special attention to the exiting spinal nerve at these levels, and possibly additional bone resection to widen the foramen.

Anatomical Consideration for Anterior Approach of Cervicothoracic Junction: A Computed Tomography Image Analysis.

In the cervicothoracic junction (CTJ), there is limited working space to perform the posterior-only approach. Therefore, a combined anterior approach is required in some cases. However, the great vessels and sternum obstruct the anterior corridor and make the anterior approach difficult. We analyzed relevant anatomical structures encountered during the anterior approach in the CTJ and evaluated the feasibility of previously reported surgical corridors. We retrospectively examined 49 patients who underwent neck computed tomography angiography between January 2015 and May 2020. Using the coronal images, we measured the intercarotid artery angle (ICAA), intercarotid artery distance (ICAD), shape of the brachiocephalic trunk (BCT), and position of the BCT base. We then measured the most cranial level requiring manubriotomy for the anterior approach (ML), the most caudal level accessible through the superior corridor (SC), and the most caudal level through the inferior corridor (IC) according to the surgeon's line of sight using the sagittal axis image. The mean ICAA and ICAD were 50.83° ± 15.23° and 33.38 ± 12.11 mm, respectively. Notably, BCT shape was of the convex type in most cases (42.9%), followed by the straight type (36.7%). In addition, the base of BCT was most commonly located inside the body (49%). Moreover, ICAA and ICAD were significantly greater in men. Although men mostly had the BCT base inside the body (64.3%), female mostly had it on the edge of the body (47.6%). Notably, ML showed the highest frequency (16.3%) in the T1 lower and upper bodies. Furthermore, through SC and IC, it was possible to approach the T4 lower body and T6 midbody, respectively. SC showed the highest frequency (16.3%) in the T3 lower body, and IC showed the highest frequency (20.4%) in the T5 midbody. ICAA and ICAD were larger and higher in men. BCT was convex and located inside the body in most cases. The accessible level of ML, SC, and IC were T1, T3, and T5, respectively. For the anterior approach in the CTJ, preoperative vascular and accessible level analysis of corridors is essential to decide on the appropriate corridor and reduce complications.

Strategies to avoid internal carotid artery injury in "sandwich" atlantoaxial dislocation patients during surgery.

To elucidate the anatomic relationship between the internal carotid artery (ICA) and the bony structures of the craniovertebral junction among "sandwich" atlantoaxial dislocation (AAD) patients, and to analyze the risks of injury during surgical procedures. The distance from the medial wall of ICA to the midsagittal plane (D1), the shortest distance between the ICA wall and the anterior cortex of the lateral mass of atlas (LMA) (D2) on the most caudal and cranial levels of LMA and the angle (A) between the sagittal plane passing through the screw entry point of C1 lateral mass(C1LM) screw and the medial tangent line of the vessel passing through the entry point were measured. Besides, the location of ICA in front of the atlantoaxial vertebra was divided into 4 categories (Z1-Z4). There was a statistically difference between the male and female patients regarding D1, and the difference between D2 at level a and level b as well as angle A between the left and right sides were statistically different (p < 0.05). Ninety-two ICAs (57.5%) were anteriorly located in Z3, 50 (31.3%) were located in Z4, 17 were located in Z2, and only one ICA was located in Z1 in all 80 patients. In "sandwich" AAD patients, particular attention should be paid to excessively medialized ICA to avoid ICA injury during trans-oral procedures, and the risk of injuring the ICA with more cranially and medially angulated C1LM screw placement was relatively less during posterior fixation procedures. A novel classification of ICA location was used to describe the relationship between ICA and LMA.

Surgical results for cervical spondylotic myelopathy with inconsistent between deep tendon reflex findings and magnetic resonance imaging findings

BackgroundTo evaluate the surgical results of patients with cervical spondylotic myelopathy (CSM) with inconsistency between deep tendon reflex findings and cervical magnetic resonance imaging (MRI) findings and to analyze the differences between patients with good and poor surgical outcomes. MethodsWe evaluated 50 subjects with CSM (30 males, 20 females; mean age: 70.4 years) who underwent posterior surgery and were followed for at least 1 year postoperatively. Matched CSM was defined as a consistent preoperative neurological pattern determined by deep tendon reflex and cervical MRI T2-weighted high-signal intramedullary area or stenosis in the most cranial compression levels. A lack of consistency was classified as unmatched CSM. Recovery rate (RR) according to Japanese Orthopaedic Association (JOA) scoring preoperatively and at 1 year postoperatively were compared between the groups. ResultsThe matched and unmatched CSM group included 27 subjects (13 males, 14 females; mean age: 68.2 years) and 23 subjects (17 males, 6 females; mean age: 72.8 years), respectively. RR was significantly higher in the matched CSM group (56.1 ± 3.7 % vs 36.8 ± 2.7 %; p = 0.002). Unmatched CSM was significantly associated with a lower RR independently of sex, patient age, surgical procedure, preoperative JOA score, diagnosis levels, and complication of diabetes. ConclusionsPostoperative JOA score RR was significantly diminished among unmatched CSM patients comprising of 46% of cases. Some patients with unmatched CSM had multiple levels of spinal canal stenosis, foraminal stenosis, and peripheral neuropathy, suggesting that surgical results were poorer than those of matched CSM.

Endplate-specific fusion rate 1year after surgery for two-level anterior cervical discectomy and fusion(ACDF).

This is a retrospective study. Implant nonfusion is an important prognostic factor for patients after anterior cervical discectomy and fusion (ACDF). This study aimed to investigate endplate-specific pseudarthrosis after ACDF, to determine if the rate of fusion is inferior in the lower endplate, and to identify any differences in clinical and radiological results. Research comparing each endplate on which the endplate affects nonfusion is limited. We analyzed 71 patients with 142 total spinal levels who underwent double-level ACDF (C4-5-6 and C5-6-7) with an allograft and plate at our hospital between January 2012 and December 2018. Fusion grades were assessed using computed tomography and the Bridwell fusion grade system at 1year postoperatively. Radiological parameters were obtained from lateral cervical radiographs collected preoperatively and at 1month and 1year after surgery. There was no difference in fusion between the C4-5-6 and C5-6-7 ACDF procedures, but the fusion rate and Bridwell fusion grade at the caudal surgery level were lower than those at the cranial surgery level (93 vs. 79%, p < 0.001). The lower endplate of the caudal fusion level showed the most common pseudarthrosis (18 of 71 [25%]). There was no difference in radiological parameters and clinical outcomes between the fusion and pseudarthrosis groups. In double-level ACDF procedures, the nonfusion rate was higher at the caudal fusion levels, especially at the lower endplates of the caudal fusion levels.

Axial Neck-Shoulder Pain After Posterior Correction and Fusion for Adolescent Idiopathic Scoliosis With Structural Thoracic Curve: Does Cranial Fusion Level Affect Neck Symptoms?

A retrospective cohort study using prospectively collected data. To investigate the incidence and impact of fusion to the upper thoracic spine on neck-shoulder symptoms after posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS). Axial neck-shoulder pain is established as a sequela of posterior cervical spine surgery and is mainly caused by the dissection of extensor muscles in the cervical and upper thoracic spine. Sixty-three female patients with AIS who underwent PSF using segmental pedicle screw constructs for structural main thoracic curve with a minimum 2-year follow-up were included. Axial neck-shoulder pain was assessed using the visual analog scale and cervical spine function domain score of the Japanese Orthopedic Association Cervical Myelopathy Evaluation Questionnaire. The patients were divided into 2 groups, a higher group (underwent fusion up to T3 or above, n=27) and a lower group (underwent fusion up to T4 or below, n=36), and radiologic and clinical outcomes were compared. The incidence of axial neck-shoulder pain (visual analog scale ≥30) preoperatively and at the 2-year follow-up was 29 and 40%, respectively. The pain and mental health domains of the Scoliosis Research Society-22 and cervical spine function domain of the Japanese Orthopedic Association Cervical Myelopathy Evaluation Questionnaire were correlated with the severity of axial neck pain. In the comparison of clinical outcomes between the 2 groups, the pain domain score of the Scoliosis Research Society-22 in the lower group was significantly better than that in the higher group at the 2-year follow-up ( P <0.05). Other parameters showed no significant differences preoperatively or at the 2-year follow-up. Female patients with AIS had a relatively high incidence of axial neck-shoulder pain after PSF, which affected their health-related quality of life. Both groups showed similar clinical outcomes, and the cranial fusion level did not affect axial neck-shoulder pain and cervical spine function. Level 3.