Postoperative bracing on clinical outcomes following posterior lumbar fusion for degenerative lumbar diseases: a meta-analysis / 中华骨科杂志

Objective:To systematically evaluate whether the early use of bracing after posterior lumbar fusion has advantages in terms of the improvement of clinical outcomes such as pain, functional disability, fusion rate, and complication rate in patients with lumbar degenerative diseases.Methods:All randomized controlled trials of bracing performed after posterior lumbar fusion in patients with lumbar degenerative diseases were searched in Pubmed, Web of Science, Embase, China national knowledge infrastructure (CNKI) and Wanfang database from January 1990 to May 2022. The data extracted were authors, year of publication, nationality, subject characteristics, sample size, surgical protocol, type and time of bracing, follow-up duration, preoperative and postoperative Oswestry disability index (ODI) and visual analogue scale (VAS), postoperative fusion rate and complication rate. The Cochrane Risk of Bias tool was used to evaluate the risk of bias. The use of fix- or random-effect models was depended on the magnitude of heterogeneity. Data analysis was performed using Stata 17.0 statistical software for meta analysis.Results:A total of five randomized controlled trials were included, all in English, with a total of 362 patients (male 144, female 218). The results of meta-analysis showed that there was no statistically significant difference in the improvement of ODI scores [ MD=1.25, 95% CI(-2.39, 4.88), P=0.501]and VAS scores[ MD=0.21, 95% CI(-0.22, 0.63), P=0.340]between the brace group and the control group after operation. In terms of fusion rate, there was no significant difference between the brace group and the control group[ OR=0.59, 95% CI(0.25, 1.38), P=0.224]. In addition, there was also no significant difference in the incidence of postoperative complications between two groups[ OR=1.12, 95% CI(0.58, 2.15), P=0.735]. Conclusion:The early use of bracing after lumbar fusion has no significant advantages in improving symptoms and functional recovery, fusion rate and surgical complications. The necessity of postoperative bracing after posterior lumbar fusion requires further high-quality research to prove.

The clinical characteristics and treatment of "sandwich" atlantoaxial dislocation / 中华骨科杂志

Objective:To evaluate the specialty of the clinical features, treatment procedure, clinical outcome, and prognosis in the patients with "sandwich" atlantoaxial dislocation (AAD).Methods:From 2008 to 2018, 160 cases with "sandwich" AAD were retrospectively selected from the case series of AAD in Peking University Third Hospital. The case series had 80 males and 80 females. The mean age at the initial visit was 35.5±14.6 years (range, 5-77). The clinical courses, treatment methodology and prognosis were reviewed. And the surgical approach, posterior fixation segment and the recovery of neurological function were mainly summarized. The atlantodental interval (ADI), the distance by which the odontoid exceeded the Chamberlain line and the cervical-medullary angle were analyzed.Results:The most common symptoms included weakness or numbness of the limbs (67.5%, 108/160), unstable gait (30%, 48/160) and vertigo (20%, 32/160). Among all, 130 cases (81.3%, 130/160) had myelopathy, with the Japanese Orthopaedic Association (JOA) scores from 4 to 16 (mean JOA scores 13.5±2.5). Cranial neuropathy was involved in 20 cases (12.5%). Radiological findings showed brainstem and/or cervical-medullar in 130 cases (81.3%), syringomyelia in 37 cases (23.1%) and Chiari malformation in 30 cases (18.8%). Computed tomography angiography (CTA) was performed in 90 cases, which showed vertebral artery anomalies in 55 cases (61.0%) and excessive medialized internal carotid artery in 5 cases (5.6%). All cases had no spinal cord or vertebral artery injury. The surgery included posterior occipito-cervical fusion (reducible dislocation, 145 cases), and transoral release followed by posterior fusion (irreducible dislocation, 15 cases). Fifty-seven cases were treated using alternative fixation technique. The average follow-up time was 50.5±22.4 months (range, 24 to 120 months). All of 152 cases (95.0%) achieved solid atlantoaxial fusion; there was no obvious osseous fusion formation on postoperative images in 6 cases (3.8%), but no atlantoaxial instability was found on dynamic radiographs; screw loosening happened in 2 patients (1.2%). Nine patients (5.6%) suffered complications, including 4 cases with recurrent dislocation, 2 screw loosening, 2 cases with bulbar paralysis and 1 wound infection. The mean postoperative JOA was 15.1±1.8 (range, 5-17), and the mean neurological improvement rate was 42.9%±33.3% in the patients with myelopathy.Conclusion:"Sandwich" AAD, a subgroup of AAD, has unique clinical features: earlier onset age and more severe myelopathy. The incidence of bone and vascular malformation is higher. So alternative surgical plan and hybrid fixation should be prepared for this subgroup of AAD.

Evidence-based guideline for clinical diagnosis and treatment of acute combination fractures of the atlas and axis in adults (version 2023) / 中华创伤杂志

The acute combination fractures of the atlas and axis in adults have a higher rate of neurological injury and early death compared with atlas or axial fractures alone. Currently, the diagnosis and treatment choices of acute combination fractures of the atlas and axis in adults are controversial because of the lack of standards for implementation. Non-operative treatments have a high incidence of bone nonunion and complications, while surgeries may easily lead to the injury of the vertebral artery, spinal cord and nerve root. At present, there are no evidence-based Chinese guidelines for the diagnosis and treatment of acute combination fractures of the atlas and axis in adults. To provide orthopedic surgeons with the most up-to-date and effective information in treating acute combination fractures of the atlas and axis in adults, the Spinal Trauma Group of Orthopedic Branch of Chinese Medical Doctor Association organized experts in the field of spinal trauma to develop the Evidence-based guideline for clinical diagnosis and treatment of acute combination fractures of the atlas and axis in adults ( version 2023) by referring to the "Management of acute combination fractures of the atlas and axis in adults" published by American Association of Neurological Surgeons (AANS)/Congress of Neurological Surgeons (CNS) in 2013 and the relevant Chinese and English literatures. Ten recommendations were made concerning the radiological diagnosis, stability judgment, treatment rules, treatment options and complications based on medical evidence, aiming to provide a reference for the diagnosis and treatment of acute combination fractures of the atlas and axis in adults.

Clinical guideline for diagnosis and treatment of adult ankylosing spondylitis combined with thoracolumbar fracture (version 2023) / 中华创伤杂志

Ankylosing spondylitis (AS) combined with spinal fractures with thoracic and lumbar fracture as the most common type shows characteristics of unstable fracture, high incidence of nerve injury, high mortality and high disability rate. The diagnosis may be missed because it is mostly caused by low-energy injury, when spinal rigidity and osteoporosis have a great impact on the accuracy of imaging examination. At the same time, the treatment choices are controversial, with no relevant specifications. Non-operative treatments can easily lead to bone nonunion, pseudoarthrosis and delayed nerve injury, while surgeries may be failed due to internal fixation failure. At present, there are no evidence-based guidelines for the diagnosis and treatment of AS combined with thoracic and lumbar fracture. In this context, the Spinal Trauma Academic Group of Orthopedics Branch of Chinese Medical Doctor Association organized experts to formulate the Clinical guideline for the diagnosis and treatment of adult ankylosing spondylitis combined with thoracolumbar fracture ( version 2023) by following the principles of evidence-based medicine and systematically review related literatures. Ten recommendations on the diagnosis, imaging evaluation, classification and treatment of AS combined with thoracic and lumbar fracture were put forward, aiming to standardize the clinical diagnosis and treatment of such disorder.

Comparison of techniques between concave distraction or convex resection in the treatment of congenital cervicothoracic scoliosis / 中华骨科杂志

Objective:To compare the technique between concave distraction and convex resection in the treatment of congenital cervicothoracic scoliosis and evaluate its curative effect.Methods:Data of congenital cervicothoracic scoliosis patients from January 2010 to January 2020 were collected, among which 5 were males and 3 were females. The patients' age was 12.5±4.5 years old (range 6-20 years old). One case had C 7 wedged vertebra, 4 cases had T 1 hemivertebra and unbalanced vertebra, 2 cases had T 2 hemivertebra and 1 case had fused facet joint and wedged lamina in T 1. All patients had different degrees of vertebra fusion. Convex resection technique (one stage anterior and posterior combined hemivertebrae resection and annular osteotomy) was used to treat 4 cases before 2015; Concave distraction technique (A combination of anterior and posterior release, intervertebral space and facet space distraction, cage placed and fusion) was used to treat 4 cases after 2015 and 2 of them had 2 segments distraction. Perioperative neurological, vascular and wound related complications were recorded. The main parameters were structure Cobb angle, cephalic and caudal compensatory Cobb angle, mandibular incline, neck tilt, shoulder balance and head shift were measured pre-operation, post-operation and at the last follow-up. Results:All patients' surgeries were completed successfully. In convex resection group, the duration of surgery was 201±100 min (range 113-300 min) per vertebra, the estimated blood loss was 294±153 ml (range 100-450 ml) per vertebra, the hospital stay was 14±3 d (range 11-18 d) and follow up time was 51±11 months (range 36-60 months). In concave distraction group, the duration of surgery was 117±14 min (range 101-129 min) per vertebra, the estimated blood loss was 119±36 ml (range 85-167 ml) per vertebra, hospital stay was 17±3 d (range 14-20 d) and follow up time was 28±21 months (range 12-60 months). Convex resection group had longer operation time and more blood loss per vertebra than concave distraction group. In convex resection group, structural Cobb angle was 45.1°±21.0° pre-operation and 22.7°±15.3° post-operation, which was corrected significantly ( Z=6.53, P=0.038). The correction rate was 54.8%±30.9%. Cephalic compensatory Cobb angle was 22.1°±8.2° pre-operation and 8.2°±5.8° post-operation, which was corrected significantly ( F=6.01, P=0.049). The correction rate was 66.8%±15.1%. Mandible incline was 7.8°±3.1° pre-operation and 3.5°±1.5° post-operation, which was corrected significantly ( F=8.02, P=0.018). The correction rate was 51.0%±29.7%. In concave distraction group, structural Cobb angle was 32.2°±27.2° pre-operation and 16.3°±16.7° post-operation, which was corrected significantly ( F=7.43, P=0.024) . The correction rate was 59.0%±24.7%. Caudal compensatory Cobb angle was 18.9°(17.2°, 32.1°) pre-operation and 9.5°±10.3° post-operation, which was corrected significantly ( Z=6.00, P=0.049). The correction rate was 64.0%±24.1%. Clavicle angle was 3.9°±2.3° pre-operation and 0.3°±0.4° post-operation, which was corrected significantly ( F=1.75, P=0.040). The correction rate was 97.0% (48.5%, 99.8%). There was no significant difference in the correction rate of all radiographic parameters between the two groups. At the last follow-up, the patients' appearance of head, neck and shoulder were improved compared with those before surgery. In convex resection group, 2 patients showed nerve root stimulation symptoms postoperatively on convex side. One patient developed C 5 nerve root palsy which weakened deltoid muscle and the other patients presented with reduced triceps muscle strength. In concave distraction group, one patient developed C 5 nerve root palsy on convex side. All these symptoms recovered by conservative treatment 3 months after operation. Conclusion:It is safe and effective to treat congenital cervicothoracic scoliosis with convex resection technique and concave distraction technique. The concave distraction technique has the advantages of more safety, less operating time, less blood loss and easier to perform and has a wider application prospect.

Research progress of epigenetic regulation in the ossification of spinal ligaments / 中华骨科杂志

Ossification of the spinal ligaments (OSL) is characterized by the appearance of pathologic bone tissue within the spinal ligamentous tissue. OSL tends to occur in the cervical and thoracic segments with important cause of spinal stenosis. Compression of the spinal cord or nerve roots by ossified masses can lead to severe neurological dysfunction, which has a tremendous impact on the quality of life of patients. However, the exact etiology and pathogenesis of OSL are still unclear. Epigenetic regulation is widespread in organisms and refers to the appearance of heritable changes in gene expression without alteration in genomic DNA sequence. As an important form of biodiversity regulation, epigenetic regulation plays an important role in development of several diseases. Epigenetic regulation has multiple manifestations in OSL, including DNA methylation, histone modifications, and non-coding RNA regulation. Sequencing tools, such as gene microarrays, have revealed significant differences in DNA methylation profiles and non-coding RNA expression between ossified and normal spinal ligaments. These differences can cause abnormal expression of osteogenesis-related target genes through direct or indirect pathways, thus affecting the ossification process of spinal ligaments. In addition, interactions between these epigenetic regulatory mechanisms constitute a large and complex regulatory network. Consequently, an in-depth understanding of the role of different epigenetic regulatory mechanisms and the linkages between them in the initiation and progression stages of OSL is expected to provide a valuable reference for the clinical diagnosis and treatment of OSL-related diseases.

The application of distraction on the concave side in the treatment of congenital cervical scoliosis / 中华骨科杂志

Objective:To explore the safety, feasibility, and short-term outcome ofdistraction on the concave side in the treatment of patients with congenital cervical scoliosis.Methods:Between August 2015 and December 2019, 11 patients with congenital cervical scoliosis underwent distraction technique on concave side, among which 5 were males and 6 were females. Age was 9.9±3.1 years old (range 6-16 years old). The primary cervical spine deformity was hemi-vertebra with different degrees of vertebra fusion. 7 cases were in C 3, 3 cases were in C 4 and 1 case was in C 5. Anterior-posterior combined approach was used. Firstly, discectomy and soft tissue release on concave side were made through anterior approach, then distraction on concave side and fusion with internal fixation were made through posterior approach and at last fixation and fusion in anterior approach were made. In this study we measured structure Cobb angle, compensatory Cobb angle, mandibular incline, shoulder balance and the angle difference of trapezius muscle preoperation and post operation. Perioperative neurological,vascular and wound related complicationswere recorded. Results:All patients' surgeries were completed successfully. Eight patients received single site distraction and 3 patients received distraction in two sites. The duration of surgery was 466±141 min (range 150-659 min), the estimated blood losswas 387±191 ml (range 100-660 ml) and follow up time was 12.2±9.5 months (range 3-24 months). Structural Cobb angle was 28.9°±13.1° pre-operation and 7.4°(3.0°, 27.7°) post-operation at 3 months, which was corrected significantly ( Z=-2.934, P=0.003). The correction rate was 58.1±26.1% (range 18.8%-97.6%). Structural Cobb angle was 13.2°±12.3°at 1 year post operation and had no significant difference compared with 3 months post operation ( t=1.960, P=0.107). Compensatory Cobb angle was 18.3°±6.1° pre-operation and 9.4°±7.3° post-operation at 3 months, which was corrected significantly ( t= 5.071, P<0.001) and the correction rate was 51.3%±28.3% (range 2.4%-94.7%). Compensatory Cobb angle was 8.9°±7.7° at 1 year follow up and was corrected significantly ( t=5.253, P=0.003) compared to 3 months after surgery and the correction rate was 61.4%±26.9%. Two patients developed C 5 nerve root dysfunction and 1 patient developed numbness on the index and middle fingers after surgery. All of them occurred on the concave side and recovered by conservative treatment. Conclusion:The application of distraction on the concave side in the treatment of congenitalcervical scoliosis is with good feasibility and clinical safety. Short-term follow-up showed excellent resultswith a promising future.

Predictive value of vertebral trabecular and endplate Hounsfield Units on cage subsidence followed posterior lumbar interbody fusion / 中华骨科杂志

Objective:To explore the predictive value of vertebral trabecular and endplate HU values on cage subsidence after posterior lumbar interbody fusion (PLIF), hope to provide reference for surgical planning.Methods:All of 72 patients with lumbar disc herniation that underwent PLIF were retrospectively reviewed, who were divided into two groups according to the occurrence of cage subsidence at one-year follow up. Cage subsidence was defined as more than 4 mm subsidence into the vertebrae valuated by CT at one-year follow up. There were 18 patients enrolled into Subsidence group and 54 patients enrolled into N-Subsidence group. The lumbar lordosis, segmental lordosis, intervertebral height, off-bed time, hospital stay, complications, the trabecular and endplate HU values of upper instrumented vertebrae (UIV) and lower instrumented vertebrae (LIV) were compared between the two groups. ROC was used to explore the thresholds of HU values.Results:There were 14 patients presented cage subsidence into the L4, 4 patients presented cage subsidence into the L5. There was no significant difference in lumbar lordosis, segmental lordosis, intervertebral height, off-bed time, hospital stay, or complications between the two groups. Both UIV and LIV trabecular and endplate showed a lower HU value in Subsidence group than those in N-Subsidence group. The most appropriate thresholds of HU value were 146, 172, 307, 254 for trabecular of UIV, trabecular of LIV, lower endplate of UIV, and upper endplate of LIV, respectively.Conclusion:Vertebral trabecular and endplate HU values could effectively predict the cage subsidence after PLIF, patients should be completely informed the risk of cage subsidence and larger cage should be recommended if they presented HU values under the certain threshold.

The Role and Mechanisms of Mechanical Stimulation in Degeneration of Vertebral Cartilage Endplates / 医用生物力学

The important function of the endplate is to transmit stress and supply nutrition. Endplate degeneration might induce or promote degeneration of the intervertebral disc, causing a series of spine diseases that seriously impair people’s health and life quality. Endplate chondrocytes can respond to mechanical stimulation, which is an important factor affecting endplate degeneration. Inappropriate mechanical stimulation will accelerate endplate degeneration. This review summarized the effects of mechanical stimulation on vertebral endplate chondrocyte apoptosis, synthesis inhibition, calcification, and extracellular matrix degradation. The endplate degeneration induced by mechanical stimulation is regulated by a complex network of signal pathways composed of various signal transduction factors. The signal pathways involved in this review included NF-κB, Wnt, Hedgehog, MAPK, RhoA/Rock-1, AKT/mTOR, TGF-β signaling pathway and miRNA related signals. The interconnection of these pathways was highlighted and summarized. Multiple signaling pathways work together to regulate endplate chondrocyte metabolism, which ultimately leads to the endplate degeneration. This review might shed light on early diagnosis and precise treatment of cartilage endplate degeneration.

Clinical guideline for surgical treatment of symptomatic chronic osteoporotic vertebral fractures / 中华创伤杂志

According to the pathological characteristics of symptomatic chronic thoracic and lumbar osteoporotic vertebral fracture (SCOVF), the different clinical treatment methods are selected, including vertebral augmentation, anterior-posterior fixation and fusion, posterior decompression fixation and fusion, and posterior correction osteotomy. However, there is still a lack of a unified understanding on how to choose appropriate treatment method for SCOVF. In order to reflect the new treatment concept and the evidence-based medicine progress of SCOVF in a timely manner and standardize its treatment, the clinical guideline for surgical treatment of SCOVF is formulated in compliance with the principle of scientificity, practicability and advancement and based on the level of evidence-based medicine.

Advance in the study of distal junctional problem after thoracolumbar surgery / 中华骨科杂志

Distal junctional problem (DJP) is one of the severe complications after spinal correction, fixation and fusion. As the number of patients receiving spinal surgery increased recently, the incidence of DJP also increased dramatically. Compared with proximal junctional problem, the incidence of DJP is low. However, the clinical symptoms are severe, and the rate of surgical revision is high in patients with distal junctional problems. DJP include distal junctional kyphosis (DJK) and distal junctional failure(DJF). The definition of DJK is confusing, however, and the most commonly used was that the distal junction Angle at the last follow-up was greater than 10° and increased by 10° compared with that before surgery. There are 6 DJF modes: progressive loss of lumbar lordosis,acute wedging in the disc below the instrumentation, fracture of LIV, osteoporotic fracture below the long rigid fixation, failure of the instrumentation at LIV, spinal stenosis and or segmental instability underneath the instrumentation. Possible risk factors for DJP include weight, age, type of spinal deformity, osteoporosis, choice of LIV, hip disease, deformity location, surgical approach, surgical procedure, fusion segments, fixation devices, LIV at L5, fixed to S1 with no iliac screws, poor restoration of spinal alignment, et al. Currently, there are some controversies in DJP, mainly including the incidence, risk factors whether needs to and how to revise. The review intends to conduct a simple literature review of the current DJP diagnostic criteria, incidence, risk factors, and other research progress, in order to improve the understanding of the distal junction problem.

Efficacy analysis of Smith-Petersen osteotomy assisted by releasing disk space from posterior approach for thoracolumbar kyphosis / 中华外科杂志

Objective@#To evaluate the efficacy and safety of Smith-Petersen osteotomy (SPO) assisted by releasing disk space from posterior approach for thoracolumbar kyphosis.@*Methods@#A review was conducted on 8 patients (3 males and 5 females) with thoracolumbar kyphosis were treated with SPO assisted by releasing disk space from posterior approach at Department of Orthopaedics, Peking University Third Hospital from June 2016 to September 2017. The age was 56.5 years (range:18-71 years). There were 3 cases of Scheuermanns kyphosis, 2 cases of degenerative kyphosis, 1 case of proximal junctional kyphosis (PJK) after lumbar surgery, and 2 cases of kyphosis after thoracolumbar laminectomy. The paired t test was used for statistical analysis in thoracolumbar kyphosis angle, osteotomy segment kyphosis angle, sagittal vertical value (SVA), visual analogue score (VAS), Oswestry dysfunction index (ODI) before and after surgery. Statistical difference was confirmed with P<0.05.@*Results@#Osteotomy level included 2 cases in T11-12, 3 cases in T12-L1, 3 cases in L1-2. The average operation time was 339 min (range: 247-416 min), bleeding volume was 1 275 ml (range: 500-2 500 ml). The mean follow-up time was 16.5 months (range: 12-24 months). The average thoracolumbar kyphosis angle was 59.9° (range: 40°-73°) pre-operation, 9.5°(range:-5.1°-20°) post-operation and 13.5°(range:-1.3°-28°) at the latest follow-up. It made an average correction with 46.4°and corrective rate with 78.0%. The osteotomy segment kyphosis angle was 37.9° (range: 26°-46°) pre-operation, -1.3° (range:-11°-13°) post-operation making an 39.2° open-up angle, and 2.0° (range:-13.5°-13°) at the latest follow-up. Lumbar lordosis was 47.5° (range: 2°-76°) pre-operation, 41.2°(range:15°-62°) post-operation and 36.9°(range:15°-58°) at the latest follow-up. SVA was 54 mm(range:-34 mm-149 mm) pre-operation and 39 mm(range:-3 mm-119 mm) at the latest follow-up. VAS score of low back pain was 6.3(range:0-9) pre-operation and 3.0(range:0-6) at the latest follow-up. ODI score was 21.9(range: 0-42) pre-operation and 11.0(range: 0-26) at latest follow-up. Comparing to pre-operation value, there were statistical difference in the thoracolumbar kyphosis angle(t= 8.547, P=0.000), osteotomy segment kyphosis angle(t=9.739, P=0.000), VAS(t=3.077, P=0.018), ODI(t=5.800, P=0.001) at the latest follow-up. There was no neuropathic complication in all patients. Cerebrospinal fluid leakage occurred in 2 cases with spinal surgery history, and recovered after symptomatic treatment.@*Conclusions@#SPO assisted by releasing disk space from posterior approach could safely achieve effective correction of rigid thoracolumbar kyphosis deformity within 40°.

Quantitative study of the effect of atlas posterior arch resection on cervical posterior decompression / 中华骨科杂志

Objective To quantitatively compare the effect of preservation or removal of atlas posterior arch on cervical posterior decompression,so as to provide a basis for reasonable selection of upper cervical spine decompression range and determination of surgical indications for atlas posterior arch resection.Methods The data of 45 patients with posterior decompression of upper cervical spine were retrospectively analyzed.According to the decompression range,the patients were divided into C2-C7 group and C1-C7 group.There were 25 cases in the C2-C7 group,19 males and 6 females,with an average age of 56.3 years (40-71 years),4 cases of cervical spondylotic myelopathy and 21 cases of ossification of the posterior longitudinal ligament of cervical spine.All of the 25 patients underwent open-door laminoplasty:20 cases with hinge side anchoring procedure and 5 cases with preservation of the unilateral posterior muscular-ligament complex procedure (titanium cable procedure).There were 20 cases in C1-C7 group,12 males and 8 females,with an average age of 58A years (44-75 years).All of the 20 cases underwent atlas posterior arch resection as well as C2-C7 open-door laminoplasty,including anchoring procedure in 1 case,titanium miniplate procedure in 4 cases,and titanium cable procedure in 15 cases.Standardized vertebral-cord distance (SVCD) at each level from atlas to level C~ was measured on T2-weighted images of MR on the mid-sagittal plane in the neutral position pedormed 3-12 months postoperatively at each individual level.As the main outcomes,the SVCD values obtained at the same level of the two groups were compared between the two groups.Shapiro-Wilk normality test was performed on the SVCD values at C1.2 and C2 levels of two groups.The area under the normal distribution curve of SVCDs was used to calculate the corresponding residual compression rate with different magnitude of compression mass to further discover the difference of the decompression effect between the two groups.Results The SVCD obtained at the level of the anterior arch of atlas (C1),the junction of odontoid process and axis (C1,2) and the middle part of axis body (C2) in the C2-C7 group was 9.91±1.34 mm,8.35±1.27 mm,and 8.22 ±1.43 mm,respectively.The SVCD at the same levels was 11.02±1.60 mm,9.72±1.24 mm,and 9.12±1.11 mm,respectively.SVCDs differed significantly in the above range between the two groups.However,from level C2,3 to C6,7,there was no significant difference in SVCDs between the two groups.The JOA score of group C2-C7 was 11.8±2.7 preoperatively and increased significantly to 14.7±1.8 at 12 months postoperatively(t=-7.006,P＜0.001) with a recovery rate of 57.0％±32.2％.The JOA score of group C1-C7 was 11.7±2.8 preoperatively and increased significantly to 14.2±2.3 at 12 months postoperatively(t=-6.177,P＜0.001) with a recovery rate of 51.9％±32.1％.Conclusion Atlas posterior arch resection can significantly increase the decompression effect of posterior cervical surgery from the anterior arch of atlas to the middle part of axis body,but it would not increase the decompression effect at level C2.3 or below.When the magnitude of the ventral compression factor exceeds the decompression limit (8.5 mm) available with C2-C7 decompression in the range from atlas to the middle of the axis body,extending the decompression range by atlas posterior arch resection is an effective means to achieve adequate decompression.

Posterior approach laminectomy combined with localized resection of ossified posterior longitudinal ligament and dekyphosis for multilevel ossification of the posterior longitudinal ligament in the thoracic spine / 中华骨科杂志

Objective To investigate the safety and effectiveness of posterior approach laminectomy combined with localized resection of ossified posterior longitudinal ligament and dekyphosis for multilevel ossification of the posterior longitudinal ligament (OPLL) in the thoracic spine.Methods Thirty-one cases of thoracic multilevel OPLL was treated with this new technique between August of 2012 and August of 2016.Twenty-nine among the 31 cases were successfully followed up more than two years.Among these 29 cases,9 were male and the other 20 were female,with an average age of 48.5±7.1 years.The average segment number of OPLLwas 6.5±2.2 (range,3-11).The average segment number of laminectomy was 7.9±2.5 (range,4-13).There were 26 cases combined with ossification of the ligamentum flavum (OLF).Posterior approach laminectomy combined with localized resection of OPLL and dekyphosis for multilevel OPLL in the thoracic spine was applied to all cases.Firstly,en-bloc laminectomy was performed to all the segments of OPLL.Then the nearest segment of ossification to the kyphotic apex and the most stenotie level was selected and limitedly resected.Finally,wedge-shaped osteotomy was conducted to decrease the kyphosis.The outcomes including recovery rate of myelopathy and the radiological changes were recorded during the post-operative follow-up.Single group pre and post analysis was conducted by using paired t-test.Results Twenty-seven cases underwent one-level circumferential decompression,and the other two case underwent two-level localized resection of the ossified posterior longitudinal ligament.The average operation time was 245.2±75.1 min (range,131-423 min).The average blood loss was 1 307.9±1 457.7 ml(range,300-6 000 ml).The average follow-up time was 40.2± 14.9 months (range,25-69 months).The kyphotic angle of the stenotic segments decreased 11.4°±3.5° averagely after the surgery,from pre-operative 28.7°±9.6° to post-operative 17.3°±8.6°.The decreased kyphotic angle was 7.4°±3.1 ° at the final follow-up with an average kyphotic angel of 22.3°± 10.3°.The average length of the resected ossified posterior longitudinal ligament was 11.3±3.9 mm,and the average shortening length of the spinal column was 5.0±3.0 mm (range,0.4-13.8 mm).The pre-operative Japanese Orthopedic Association (JOA) score was 4.3±2.2 averagely (range,1-9),and the final JOA score increased to 9.3±2.3 (rang,3-11).The average recover rate was 85.7％ (range,-100％ to 100％),and the rate of excellent or good was 89.7％.Among the 29 cases,6 cases occurred post-operative transient deterioration and regained a satisfactory recovery eventually;one case occurred post-operative paraplegia and never recovered;19 cases occurred post-operative cerebrospinal fluid leakage and healed under conservative treatment.Conclusion For the thoracic multilevel OPLL,one-stage posterior approach laminectomy combined with localized resection of the ossified posterior longitudinal ligament and dekyphosis can significantly improve the outcomes of the myelopathy with low rate of post-operative paraplegia.Therefore,this new surgery technique is a safe and effective treatment for multilevel OPLL in thoracic spine.

The evaluation of osteogenic potency of ligament cells in thoracic ossification of the ligamentum flavum and relevant transcriptome high-throughput sequencing analysis / 中华骨科杂志

Objective To investigate the osteogenic differentiation potency of ligament cells in thoracic ossification of the ligamentum flavum (TOLF) and analyze further by using transcriptome high-throughput sequencing.Methods Clinically,the patients with non-TOLF and TOLF (n=10 in each group) who underwent surgery in our hospital from October 2015 to April 2016 were included in this study.The primary ligament cells that derived from the two groups were separately cultured and induced osteogenesis with 15％ strength of cyclic mechanical stress for 12h and 24h using a device called Flexcell FX-4000.The ALP activity was determined to evaluate the osteogenesis using quantitative analysis and ALP staining assay.Real-time PCR and westernblotting were used to detect the mRNA and protein expression of osteogenic-related genes including ALP,BMP-2 and Osteocalcin.Then,three patients in each group were included in the study of transcriptome high-throughput sequencing and bioinformatics analysis using Illumina HiSeqTM 2500 sequencing platform to compare further.Results The morphology of the cells that derived from two groups was basically similar,all presented an elongate spindle-shape.To evaluate the ostogenesis,ALP activity assays including quantitative and staining assays were performed.Under microscope,the ALP staining in the TOLF group was higher than non-TOLF group and increased with the longer duration of stress induction.The result of semi-quantitative analysis showed the stained area and positive cells in TOLF group were more than non-TOLF group significantly at 0 h,and were increased with the induction.The results of quantitative analysis showed ALP activity in the TOLF group was significantly higher than non-TOLF group and were increased with the induction significantly all the time.But no significant change in ALP staining or quantitative analysis was found in non-TOLF.The results of real-time PCR indicated that the expression of ostegenic markers above in the TOLF group was more than non-TOLF group significantly except the expression of OCN at 0 h.The expression of the three ostegenic markers in TOLF group was increased with the stress induction for 12 h and 24 h significantly except the expression of BMP-2 and OCN at 12 h.The results of western-blotting indicated that the expression of the three ostegenic markers above in the TOLF group was more than non-TOLF group significantly except the expression of ALP at 0 h.The expression of the three ostegenic markers in TOLF group was increased with the stress induction for 12 h and 24 h,but only the expression of ALP at 24 h was significant.And no significant change in the expression of mRNA and protein was found in non-TOLF group.In the transcriptome analysis,671 genes of TOLF group were up-regulated and 314 genes were found to be down-regulated compared to the control group.In addition,22 significant GO terms associated with upregulated genes were found to be closely related to ossification.Conclusion TOLF ligament cells have high osteogenic differentiation potency,which could express obvious osteogenesis-related gene spectrum,and differentially expressed genes including L1RL1 、PTHLH、DKK1 、BMP6、SPP1 and FGF1 may be related with the osteogenic potency of ligament cells in thoracic ossification.

Polymicrobial and Monomicrobial Infections after Spinal Surgery: A Retrospective Study to Determine which Infection is more Severe

STUDY DESIGN: A retrospective clinical review. PURPOSE: To investigate the difference in clinical manifestations and severity between polymicrobial and monomicrobial infections after spinal surgery. OVERVIEW OF LITERATURE: Surgical site infections (SSIs) after spinal surgery are a major diagnostic and therapeutic challenge for spinal surgeons. Polymicrobial infections after spinal surgery seem to result in poorer outcomes than monomicrobial infections because of complementary resistance to antibiotics. However, comparison of the clinical manifestations and severity between polymicrobial and monomicrobial infections are limited. METHODS: Sixty-seven patients with SSIs after spinal surgery were studied: 20 patients with polymicrobial infections and 47 with monomicrobial infections. Pathogenic bacteria identified were counted and classified. Age, sex, and body mass index were compared between the two groups to identify homogeneity. The groups were compared for clinical manifestations by surgical site, postoperative time to infection, infection site, incisional drainage, incisional swelling, incisional pain, neurological signs, temperature, white blood cell count, and the percentage of neutrophils. Finally, the groups were compared for severity by hospital stay, number of rehospitalizations, number of debridements, duration of antibiotics administration, number of antibiotics administered, and implant removal. RESULTS: Polymicrobial infections comprised 29.9% of SSIs after spinal surgery, and most polymicrobial infections (70.0%) were caused by two species of bacteria only. There was no difference between the groups in terms of clinical manifestations and severity. In total, 96 bacterial strains were isolated from the spinal wounds: 60 strains were gram-positive and 36 were gram-negative pathogenic bacteria. Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, and Enterobacter cloacae were cultured in order of the frequency of appearance. CONCLUSIONS: Most polymicrobial infections were caused by two bacterial species after spinal surgery. There was no difference in clinical manifestations or severity between polymicrobial and monomicrobial infections.

Analysis of Global Sagittal Postural Patterns in Asymptomatic Chinese Adults

STUDY DESIGN: A prospective imaging study. PURPOSE: To characterize the distribution of the global sagittal postural patterns in asymptomatic Chinese adults using Roussouly classification. OVERVIEW OF LITERATURE: The norms of sagittal parameters in asymptomatic Chinese population have been previously described, but no report described their global sagittal postural patterns as characterized by Roussouly classification. METHODS: A cohort of 272 asymptomatic Chinese adults was recruited. Data was assimilated by reviewing the films for each subject. Sagittal parameters were measured and sagittal postural patterns were then determined according to Roussouly classification. The pattern distributions were compared across genders within the study cohort. We also compared the data across different ethnicities from our study and a previous study to further characterize Chinese sagittal postures. RESULTS: The cohort included 161 males and 111 females, with mean age of 23.2±4.4 years. The average descriptive results were as below: pelvic incidence (PI) 46.4°±9.6°, thoracic kyphosis (TK) 24.2°±9.0°, lumbar lordosis (LL) 50.6°±10.6°, sacral slope (SS) 37.2°±7.6°, pelvic tilt (PT) 9.4°±6.8°, spinosacral angle (SSA) 131.1°±7.5° and sagittal vertical axis (SVA) 17.24±32.36 mm. Despite a significant difference between two genders in LL, PI, SSA, and SVA, no difference was found in the distribution of Roussouly types among them. 47.8% of our cohort belonged to Roussouly type 3, while type 1, 2 and 4 comprised 23.2%, 14.0% and 15.1% of the subjects, respectively. Roussouly classification was capable of categorizing sagittal parameters except for the PT. This study also found that 4.4% of the recruited subjects belonged to the C7-anterior subgroup. CONCLUSIONS: From a characterization of the sagittal postural patterns of asymptomatic Chinese adults using Roussouly classification, the distribution was similar between Chinese males and females; however, from a cross-study comparison, it was different between asymptomatic Chinese and Caucasian adults, with a higher proportion of Roussouly type 3 in Chinese adults.

Analysis of risk factors for deep surgical site infection after posterior thoracic and lumbar surgery / 中华外科杂志

<p><b>OBJECTIVE</b>To study the risk factors for deep surgical site infection after posterior thoracic and lumbar surgery.</p><p><b>METHODS</b>The medical data of the patients with deep surgical site infection after posterior thoracic and lumbar surgery from January 2008 to December 2013 were reviewed.For each case patient, 3 non-infected controls were randomly selected from the same database of all patients who underwent posterior thoracic and lumbar surgery.Patients who had diagnosis of spinal fractures, infection, tuberculosis, and tumor were excluded. The microbiology and related factors were collected and analyzed. T-test, χ2 test and Logistic analysis were used to analyze the data, respectively.</p><p><b>RESULTS</b>Ninety-nine cases were identified (infection group), 57 men and 42 women, average 54.5 years old, average body mass index 26.4 kg/m2. Fifty-five (55.6%) patients were identified with organisms, and the most common identified organism was Staphylococcus Aureus. Compared with the cases in the control group (44.4 g/L), the cases in the infection group (43.1 g/L) had a significant low albumin preoperatively (P=0.001). Multivariate Logistic analysis showed that obesity (OR=2.102, 95% CI=1.259-3.508), diabetes (OR=1.926, 95% CI=1.041-3.563), number of surgical levels≥3 (OR=1.985, 95% CI=1.130-3.486) were risk factors for this complication (P<0.05).</p><p><b>CONCLUSION</b>For deep surgical site infection after posterior thoracic and lumbar surgery, obesity, diabetes, preoperative low albumin and number of surgical levels≥3 are risk factors.</p>

Thoracic laminectomy with dekyphosis for thoracic myelopathy secondary to multi-segmental ossification of the posterior longitudinal ligament / 中华骨科杂志

Objective To investigate the safety and efficiency of thoracic laminectomy with dekyphosis for thoracic myelopathy due to multi-segmental ossification of the posterior ligaments.Methods The clinical data of five cases of thoracic myelopathy due to multi-segmental ossification of longitudinal ligaments who were surgically treated in our hospital between August 2012 and March 2013 were retrospectively analyzed,among which two were male and the other three were female,with an average age of 52 (range,45-56) years old.The pre-operative duration ranged from 2 months to 6 years.All five cases were suffering from progressive bilateral partial paraplegia with an average preoperative JOA score 3.8 (range,3-6),an average segment-number of ossification of the posterior ligaments 7.6 (range,5-10),and also an average segment-number of 5.0 (range,2-10) ossification of the ligamentum flavum.All the five cases showed different kyphosis at the stenotic area of thoracic spine,with an average kyphotic angle (Cobb) of 35.8° (range,22°-56°).Their pre-operative Japanese Orthopaedic Association score (JOA) was 3.8 averagely (range,3-6).Clinical features,operation time,blood loss,perioperative complications and postoperative outcome were recorded.Results The segment number of laminectomy of these five cases was 8.2 averagely.The segment number of dekyphosis was 2 for 2 cases and 1 for the other 3 cases,with a average dekyphotic degree of 7.8° (range,2°-15°).The average operation time was 6.3 hours (range,5.5-7.0 hours) and the average blood loss was 3900 ml.The perioperative complications included cerebrospinal fluid leakage in 4 cases who were treated conservatively,and epidural hematoma in 1 case who underwent reoperation for removing the hematoma.All cases were followed up for 21 to 27 months,and their average final JOA score was 10,with an average recovery rate of 85.6％,and a rate of excellent or good was 100％ by the modified Epstein standard.Conclusion The result of thoracic laminectomy combined with dekyphosis for thoracic myelopathy due to multi-segmental ossification of longitudinal ligaments is quite satisfying,however this procedure is demanding with a long operation time,a huge blood loss and a high complication rate.

Decompression alone versus decompression with instrumented fusion for young patients with single-level lumbar disc herniation: a short-term prospective comparative study / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>For young patients, the surgical method for lumbar disc herniation remains controversial. The aim of this study was to prospectively determine the short-term clinical outcome after surgery for young patients with lumbar disc herniation.</p><p><b>METHODS</b>In this prospective comparative study between April 2010 and August 2011, a total of 80 patients underwent primary surgery at a single level for lumbar disc herniation. The patients were divided into two groups: decompression alone and decompression with instrumented fusion. An independent examiner clinically evaluated the patients at preoperation and at 1, 3, 6, and 12 months after surgery. The patients filled out the instruments for back and leg pain using a Visual Analog Scale (VAS), Oswestry Low Back Pain Disability Questionnaire (ODI), and Japanese Orthopaedic Association (JOA) scores. The differences between the two groups were analyzed.</p><p><b>RESULTS</b>The mean age of all the patients at the time of surgery was 33.7 years. Of the 80 patients, 38 patients underwent decompression alone and 42 patients underwent posterior lumbar interbody fusion. Increasing complexity of surgery was associated with a longer surgery time, greater blood loss, and a longer hospital stay after surgery. Both methods of surgery independently improved outcomes compared with baseline status based on VAS, ODI, and JOA scores (P < 0.05), and no significant differences were found between the two groups at most of the measuring points in time, although patients with decompression alone had a higher JOA score (P = 0.016) and higher JOA recovery rate (P = 0.010) at the 3-month follow-up.</p><p><b>CONCLUSIONS</b>The short-term results of our study showed that both methods of surgery obtained effective clinical outcomes, but decompression alone had some advantages (shorter surgery time, less blood loss, shorter hospital stay, and lower cost) compared with decompression with instrumented fusion. Young patients with decompression alone could achieve great physical function earlier.</p>