Search

To verify the effectiveness of anterior retropharyngeal release followed by posterior open reduction using long arm reduction screws combined with intra-articular fusion with a cage filled with the local autologous bone for treating fixed Type III atlantoaxial rotatory fixation (AARF).Data from 6 children with fixed AARF were retrospectively reviewed. All patients underwent anterior retropharyngeal release followed by posterior open reduction using long-arm reduction screws combined with intra-articular fusion with a cage filled with local autologous bone. Outcomes were measured using the atlantodental interval value, the Japanese Orthopedic Association score and visual analog scale for neck pain. Patient age, sex, operation time, blood loss, and bone fusion time were recorded. Complications related to the operation were also recorded.All patients achieved complete reduction and solid bone fusion at follow-up. The atlantodental interval dropped to 2.1 ± 0.5 mm after the operation from a preoperative score of 15.3 ± 3.1 mm (P 0.05). Japanese Orthopedic Association score significantly improved from a preoperative score of 15.3 ± 0.5 to 17 ± 0 at the final follow-up (P 0.05). Visual analog scale for neck pain markedly decreased from preoperative 4.5 ± 1.0 to 0.2 ± 0.4 at the final follow-up (P 0.05). No complication related to the surgical approach or instrumentation was observed.One-stage anterior retropharyngeal release followed by posterior open reduction combined with intra-articular cage fusion is effective in treating chronic fixed type III AARF.

The structural bone grafting (SBG) technique provided high fusion rate and satisfied outcomes for treating atlantoaxial dislocation, but it is unclear whether the atlantoaxial intra-articular cage (AIC) technique can provide clinical results comparable with SBG technique.To compare the outcomes of 2 bone graft techniques applied in posterior C1-C2 screw-rod fixation and fusion surgery for treating atlantoaxial dislocation.The data from 55 patients with atlantoaxial dislocation were retrospectively reviewed. The SBG technique had been used in 29 patients and the AIC technique in 26 patients. The outcomes were evaluated using the Japanese Orthopedic Association scale score, Neck Disability Index, and visual analog scale score for neck pain and compared between the 2 groups. The donor site complications were also recorded in SBG group, and donor site pain was assessed using a visual analog scale.In the final follow-up, the bone fusion rate was 100% in both groups. No significant differences were found in the bone fusion time between the 2 groups ( P.05). Postoperatively, the Japanese Orthopedic Association, Neck Disability Index, and visual analog scale score for neck pain indexes improved significantly within both SBG (all P.05) and AIC groups (all P.05). Nevertheless, there were no statistically significant differences between the 2 groups (all P.05).The SBG and AIC techniques were both effective for achieving atlantoaxial arthrodesis, and the AIC technique is a perfect alternative to the SBG technique when the posterior arch of C1 is incompetent.

Incurable implant-related infection may cause catastrophic consequences due to the existence of a biofilm that resists the infiltration of host immune cells and antibiotics. Innovative approaches inspired by nanomedicine, e.g., engineering innovative multifunctional bionic coating systems on the surface of implants, are becoming increasingly attractive. Herein, 2D black phosphorus nanosheets (BPs) were loaded onto a hydroxyapatite (HA)-coated metal implant to construct a BPs@HA composite coating. With its photothermal conversion effect and

A retro-odontoid pseudotumor (ROP) is commonly associated with atlantoaxial instability or rheumatoid arthritis. However, ROP in the absence of atlantoaxial instability or rheumatoid arthritis, which is termed idiopathic ROP (IROP), is a rare condition. The pathomechanisms and optimal treatment strategies for IROP remain controversial. The aim of the present study was to evaluate the radiographic and clinical characteristics of IROP patients and to assess the efficiency of atlantoaxial/occipitocervical fusion on IROP regression.Data from 5 patients diagnosed with IROP were retrospectively reviewed. Posterior atlantoaxial or occipitocervical fixation and fusion were performed in 4 patients and C1 posterior arch resection alone in 1 patient. The patients' features, surgical procedures, and complications were recorded. The retro-odontoid soft tissue thickness was measured on preoperative and postoperative magnetic resonance imaging to evaluate IROP regression.The mean follow-up time was 37 months. ROP regression was achieved in patients who received atlantoaxial/occipitocervical fusion, but not for the patient with C1 posterior resection alone. There were no observed neurovascular complications associated with surgery.IROP was related to a restricted range of motion of the subaxial spine. Upper cervical fixation is an optional treatment that produces IROP regression over time. By contrast, direct removal of the IROP is unnecessary.

Some atlantoaxial rotatory fixations (AARFs) cannot be classified according to the Fielding and Hawkins classification. This study aimed to introduce a new subtype of AARF (type IIIa AARF) with a C1 anterior displacement5 mm, but with one lateral mass being displaced anteriorly and another posteriorly.Data from 10 cases of AARF with anterior C1 displacement of5 mm were retrospectively reviewed. The exclusion criteria were as follows:1) type I, II, or IV AARF according to the Fielding and Hawkins classification; 2) cases caused by trauma, tumor, or infection; 3) AARF with os odontoideum or odontoid fracture;and 4）age ≥18 years. Imaging features were analyzed. The atlanto-dental interval (ADI) was measured to evaluate C1 anterior displacement.Three cases that did not match type III AARF were classified under type IIIa AARF. They had the following common imaging features: 1) ADI of5 mm, being similar to type III AARF; 2) one lateral mass of C1 displaced anteriorly and the other posteriorly (the most important feature distinguishing the type from type III AARF in which both C1 lateral masses displaced anteriorly); and 3) C1-C2 separation angle (mean 44.2±2.9°) being larger than that in type III AARF.AARF with anterior C1 displacement of5 mm, but with one lateral mass displaced anteriorly and the other posteriorly, was defined as type IIIa AARF. It should not be confused with type III AARF because these two types differ in biomechanics and imaging parameters.

Atlantoaxial dislocation (AAD) is classified into reducible AAD and irreducible AAD (IRAAD). Anterior or posterior releasing followed by occipitocervical/atlantoaxial fusion is often performed for IRAAD, but is technically demanding. This study aimed to evaluate the results of the posterior open reduction technique without releasing the atlantoaxial joint in the treatment of potentially reducible AAD (PRAAD) caused by transverse ligament laxity in patients with rheumatoid arthritis (RA).Data from 38 RA patients who experienced PRAAD due to transverse ligament laxity were retrospectively reviewed. They all underwent posterior open reduction and fusion without releasing the atlantoaxial joint. Outcomes were evaluated by using atlantodental interval, modified Japanese Orthopedic Association scores, Nurick grade, Neck Disability Index, and visual analog scale score for neck pain.All the patients achieved solid bone fusion at follow-up. The mean atlantodental interval was reduced to 5.6 ± 0.7 mm and 2.1 ± 0.5 mm after traction and operation, respectively, from a preoperative score of 8.2 ± 0.6 mm (P 0.05). Compared with the respective preoperative values, the mean modified Japanese Orthopedic Association score and Nurick grade were significantly increased at the final follow-up (both P 0.05), whereas the Neck Disability Index and visual analog scale score for neck pain were significantly decreased (both P 0.05).AAD with partial reduction after skeletal traction for 48 hours should be defined as PRAAD, not IRAAD. Open reduction with a C1-C2 pedicle screw-rod system can be safely and effectively applied in the treatment of PRAAD due to transverse ligament laxity in patients with RA.

To assess and compare clinical outcomes and sagittal balance after unstable hangman fracture between C2-C3 anterior discectomy and fusion (ACDF) and posterior C2-C3 short-segment fixation and fusion.A total of 45 patients underwent ACDF (20 patients) and posterior C2-C3 short-segment fixation and fusion (25 patients) between March 2005 and June 2013. Visual analog scale, Neck Disability Index, Odom grading system, American Spinal Injury Association Impairment Scale (AIS), C2-C3 angle, displacement of C2-C3 (DThe follow-up duration was 20.0 months (range, 18.0-21.0 months) in the anterior group and 19.0 months (range, 18.0-20.0 months) in the posterior group. Satisfactory bony fusions were achieved in 2 groups. The VAS score and NDI score were significantly lower than their respective preoperative score in each group (P0.001), whereas there was no difference between 2 groups (P = 0.78; P = 0.85). A statistically significant decrease of O-C2 angle and cSVA between preoperative and postoperative data was found in each group (P0.001), and CL increased statistically (P0.001). For O-C2 angle, CL, and cSVA, the changes of parameters after the posterior approach were more significant than after the anterior approach (P0.05).Both anterior and posterior surgical techniques are effective for unstable hangman fracture and both can restore the sagittal balance of the cervical spine. Furthermore, the posterior approach has an advantage over the anterior approach in promoting recovery of cervical sagittal balance.

Combined lateral mass screw-rod (LMSR) fixation and anterior cervical discectomy and fusion (ACDF) surgery is currently the most widely described and accepted procedure for subaxial cervical facet fracture with traumatic disc herniation. Recent biomechanical studies have demonstrated that the use of transfacet screw (TFS) can be considered as a simple alternative method to LMSR. However, to date, little is known about the feasibility and effectiveness of TFS in the combined approach. The aim of this study was to compare the clinical and radiographic results of TFS + ACDF surgery and LMSR + ACDF surgery, and to provide a less invasive alternative technique for spine surgeons.We retrospectively reviewed patients with unilateral cervical facet fracture with traumatic disc herniation who had undergone TFS + ACDF (N = 36) or LMSR + ACDF (N = 34) with a minimum 2-year follow-up. Clinical assessments, which included American Spinal Injury Association impairment scale (AIS), visual analog scale for neck pain (VASSNP) score and patient satisfaction, were made before surgery and at follow-up. For the radiographic outcomes, the instability parameters of segmental kyphosis and sagittal translation were measured.The demographic characteristics of the two groups of patients were similar. In terms of clinical outcomes, both two groups were associated with significant improvements at the final follow-up. There were no significant between-group differences in VASSNP score or patient satisfaction (both P 0.05). The LMSR + ACDF group suffered more blood loss and had longer operative time (mean 206.0 ml; mean 274.4 min, respectively) than in the TFS + ACDF group (mean 110.0 ml; mean 142.8 min, respectively) (P 0.001 for both comparisons). For the radiographic results, the segmental kyphosis and sagittal translation were significantly corrected after surgery in both groups (P 0.001 for both groups), and no significant differences were found between groups at the last follow-up (P 0.05).In the absence of any self-evident clinical and radiographic benefits of one technique over the other (TFS + ACDF vs. LMSR + ACDF), we recommend combined TFS + ACDF surgery as a safe and less invasive alternative treatment for unilateral cervical facet fractures with traumatic disc herniation, as it was associated with a shorter duration of surgery and lower estimated blood loss than LMSR + ACDF surgery.

Immediate mechanical stability is a prerequisite for fracture healing. In addition to bringing immediate mechanical stability in fracture site, implants with bioactive coating can release active substance to accelerate bone-fracture healing. However, limited drug-loading capacity of established coatings weakens their biological functions, which urges the engineering of more effective coating biomaterials for accelerating fracture healing. Herein, mesoporous organosilica nanoparticles (MONs), as miR-34a delivers, are loaded onto hydroxyapatite (HA)-coated Kirschner wire to engineer a HA/MONs@miR-34a composite coating. The composite coating can effectively deliver miR-34a into osteoclasts, generate gene dose-dependent inhibiting effect on differentiation and resorptive activity of osteoclasts by regulating multiple downstream gene expression at the early stage of fracture healing, which additionally exhibits decent bone regeneration potentials as evidenced in rat tibial fracture model. In particular, differentially expressed genes regulated by miR-34a are identified using RNA-seq followed by bioinformatics analysis. Functional enrichment analysis reveals that genes with altered expression mainly distribute in mainly distribute in DNA replication and cell cycle, which are associated with the development of osteoclasts. This work not only demonstrates the high clinical translation potential of HA/MONs@miR-34a to accelerate fracture healing, but also reveals the underlying molecular mechanism of regulating physiological functions of osteoclasts based on analysis of single-cell RNA sequencing.

Background: Cervical laminoplasty is a well-established surgical treatment for patients with cervical myelopathy due to OPLL. However, for cases with OPLL involving C2 segment, some surgeon preferred C2EL technique, but destruction of muscles attaching at C2 spinous process and lamina is inevitable. While C2DEL technique was also available which cause less destruction to the structures associated with C2. Nevertheless, it is still not confirmed whether it can achieve similar outcomes as C2EL. This study aimed to compare the clinical and radiographic outcomes of C2 dome-like expansive laminoplasty technique(C2DEL) and C2 extended laminoplasty technique(C2EL) applied in the treatment of cervical ossification of posterior longitudinal ligament (OPLL)involving C2 segment.Methods: Data of 56 patients with OPLL involving C2 segment who underwent cervical laminoplasty were retrospectively reviewed. 26 patients received C2EL technique while C2DEL technique was applied in another 30 patients. Functional outcomes evaluated by visual analog scale score for neck pain (VASSNP), Neck Disability Index (NDI), Japanese Orthopedic Association (JOA) score and Health-Related Quality-of-Life Short Form-36 Physical Component Summary (SF-36 PCS) were recorded and compared pre- and postoperatively. The radiographic outcomes assessed by the Cobb angle and range of motion (ROM) of cervical spine at C2-C7, as well as decompression effect at C2 level evaluated by space available for spinal cord (SAC) were measured in two groups. The intraoperative parameters including total blood loss and operation time were documented and compared between 2 groups.Results: At the final follow-up, JOA scores, NDI, and SF-36 PCS were significantly improved in both groups(all P＜0.05), but no significant differences were identified between two groups. VASSNP was reduced significantly in both groups(P＜0.05), but the cases in C2EL group experienced more severe neck pain than that of C2EL group(P＜0.05). Cobb angle at C2 and C7 and the cervical ROM in both groups reduced greatly, the SAC at C2 improved postoperatively and no significant difference was identified intergroup. No serious complications related to the surgical approach and instrumentation were observed in either group.Conclusion: C2DEL was comparable to C2EL for treating OPLL involving C2 segment. C2DEL was an ideal alternative treatment strategy for OPLL involving the C2 segment.

Objective Although the C2 pedicle screw (C2PS) is currently the most biomechanically robust option for C2 fixation, the high-riding vertebral artery (HRVA) precludes safe C2PS placement. However, unintentional partial C2 pedicle perforation and vertebral foramen violation due to C2PS placement without neurovascular complications occurred frequently in clinic. Therefore, we have attempted to apply C2 partial transpedicular screw (C2PTS) in patients with HRVA with satisfactory preliminary outcomes. The aim of the present study is to introduce the C2PTS technique and report the preliminary radiological and clinical outcomes of application of C2PTS. Patients and methods The data of 15 patients with atlantoaxial dislocation underwent atlantoaxial arthrodesis with posterior screw-rod construct were retrospectively reviewed. All patients had unilateral or bilateral HRVA that precluded safe C2PS placement and C2PTS was used as an alternative. In this technique, a Penfield dissector was used to properly mobilize the HRVA inferiorly to preclude vertebral artery injury and pave the way for C2PTS placement. The C2PTS travelled under the superior border of the isthmus and toward the ipsilateral atlantoaxial articulation. The implant position and atlantoaxial reduction were evaluated using computed tomography (CT) scans and vertebral artery (VA) was assessed using CT angiography postoperatively. Results Satisfactory C2PTS placement and atlantoaxial reduction were achieved in all patients. Postoperatively, no vertebral artery injury and implant failure were observed, and bone fusion was achieved in all the patients. Additionally, there were no VA occlusion or stenosis due to screws demonstrated on VA CT angiography. Conclusion C2PTS can achieve three-column fixation of axis and is an efficient alternative to C2PS which is prohibited due to HRVA; also, gently mobilizing the HRVA inferiorly is mandatory to prevent vertebral artery injury during C2PTS placement.

Several bone grafting techniques for posterior atlantoaxial arthrodesis have been reported. The techniques of placing a cancellous morselized bone graft (MBG) on decorticated surfaces of the atlantoaxial complex and securing a structural iliac bone graft (SBG) between C1 and C2 have been used widely. The aim of the present study was to compare the outcomes of these 2 bone grafting techniques for atlantoaxial arthrodesis.The data from 64 patients with reducible atlantoaxial dislocation treated using posterior C1-C2 screw-rod fixation and fusion were retrospectively reviewed. The MBG technique had been used in 32 patients and the SBG technique in 32 patients. The time required for bone fusion was recorded. The outcomes were evaluated using the Japanese Orthopaedic Association scale score, Neck Disability Index, visual analog scale (VAS) score for neck pain, patient satisfaction, and neck stiffness and compared between the 2 groups. The donor site complications were also compared, and donor site pain was assessed using a VAS.At the final follow-up, the bone fusion rate was 100% in both groups. No significant differences were found in the bone fusion time or donor site pain between the 2 groups (P0.05). Postoperatively, The Japanese Orthopaedic Association scale scores, Neck Disability Index, and VAS score for neck pain had improved significantly within both groups (P0.05), with no statistically significant differences between the 2 groups (P0.05). Additionally, no differences were found between the 2 groups in patient satisfaction and neck stiffness postoperatively (P0.05).The MBG and SBG techniques were both effective for atlantoaxial arthrodesis, with the advantages of reducing the potential risk of catastrophic bleeding of the epidural venous plexus and C2 nerve root injury.

The dysregulation of ubiquitin ligase is the cause of many human diseases. Tripartite motif protein 32 (TRIM32) is an E3 ubiquitin ligase whose role in nucleus pulposus (NP) cell apoptosis is unclear. The expression of TRIM family protein and β-catenin in 40 NP tissue samples was detected by RT-PCR. Interleukin (IL)-1β or tumor necrosis factor (TNF)-α was used to treat rat NP cells. Knockdown and overexpression of Trim32 were achieved using specific siRNA and recombinant plasmids. Western blotting, RT-PCR, and flow cytometry were used to assess the expression of TRIM32/β-catenin and the apoptosis rate of NP cells. Coimmunoprecipitation was adopted to analyze the possible interactions between AXIN1 and TRIM32. In clinical samples, TRIM32 expression was of positive relevance with the expression of CTNNB1 (β-catenin). In vitro, apoptosis of IL-1β- or TNF-α-treated rat NP cells was induced through upregulated Trim32 expression and activated β-catenin signaling, whereas Trim32 siRNA and inhibition of β-catenin reversed the induction effect of cytokines. Further studies indicated that TRIM32 activated the β-catenin signaling pathway through ubiquitination of AXIN1, thereby regulating apoptosis. Collectively, this study reveals that TRIM32 promotes inflammatory factor-induced apoptosis of rat NP cells, in part by direct degradation of AXIN1 to trigger β-catenin signaling.

Background Surgery is usually recommended for thoracolumbar fracture with neurologic deficit. However, traditional open posterior approach requires massive paraspinal muscles stripping, and the canal decompression may be limited and incomplete. We aimed to investigate a new approach via the Wiltse approach and the Kambin’s Triangle. Methods Twenty-one consecutive patients with traumatic upper lumbar fracture who received this new approach surgery between January 2015 and January 2016 constituted the new approach group. Twenty-nine patients received the traditional open posterior surgery between January 2014 and January 2015 were classified as the traditional posterior surgery group. Surgical informations including operative time, blood loss, drainage volume, hospitalization days were collected and compared among the two groups. The American Spinal Injury Association (ASIA) impairment scale and Visual Analog Score (VAS) were evaluated preoperatively, postoperatively and at 12 months follow-up. Results Patients in the new approach group had fewer operation time (128.3 ± 25.1 vs 151 ± 32.2 min, P = 0.01), less blood loss (243.8 ± 135.5 vs 437.8 ± 224.9 ml, P = 0.001) and drainage volume (70.7 ± 57.2 vs 271.7 ± 95.5 ml, P P = 0.004). Similar neurologic recovery according to ASIA grade was achieved in both groups (Recovery index: 0.90 ± 0.53 vs 0.86 ± 0.51, P = 0.778). While the pain level was significantly lower in the new approach group postoperatively (2.6 ± 0.7 vs 3.5 ± 0.9, P P Conclusion The present new approach was successfully applied in the treatment of upper lumbar fracture with neurologic deficit. It can reduce iatrogenic trauma and achieve similar or better outcomes compared to the traditional posterior surgery.

To investigate the role of lumbosacral transitional vertebra (LSTV) in the pathogenesis of adolescent lumbar disc herniation (ALDH) and the association between LSTV type and the herniation level of ALDH.This study was a retrospective case-control analysis of roentgenographic images. All adolescent patients who received surgical treatment for L4/5 or L5/S1 single level lumbar disc herniation in our department from 2010 to 2015 were eligible for the ALDH group. All adolescent patients admitted to our hospital during the same period and who had ever undergone a plain anteroposterior radiologic examination of the abdomen and met the inclusion criteria that ensured the absence of any spinal disorders were selected into the control group. The anteroposterior lumbar or abdomen roentgenograms were collected to identify the LSTV. The incidence of LSTV in the ALDH group and the control group were compared. Among the ALDH group, the association between LSTV type (sacralization or lumbarization) and the herniation level of ALDH were evaluated.A total of 80 adolescent patients were included in the ALDH group and 92 asymptomatic adolescents were included in the control group. LSTV was found in 24 patients (30%) in ALDH group compared with 7 patients (7.6%) in the control group (P0.001; odds ratio, 5.2; 95% confidence interval 2.1, 12.9). Among the adolescent patients with sacralization, the L4/5 disc herniation was significantly more common than L5/S1 (81.3% vs. 18.7%; P = 0.019).The LSTV is associated with LDH in adolescents and the sacralization of L5 may contribute to the L4/5 disc herniation in adolescent patients.

In this study, we investigated the role of the spindle checkpoint protein SPC24 in osteosarcoma progression. SPC24 knockdown in 143B and U2OS osteosarcoma cells decreased cell growth, survival and invasiveness. The SPC24 knockdown cells also exhibited low EGFR, Ras and phospho-ERK levels and high E-cadherin levels, suggesting inhibition of EGFR/Ras/ERK signaling and epithelial-to-mesenchymal transitioning. Xenografted SPC24 knockdown osteosarcoma cells showed reduced tumor growth in nude mice with decreased EGFR and phospho-ERK levels and increased E-cadherin levels. By contrast, human osteosarcoma tissue samples showed high SPC24 and phospho-ERK levels and low E-cadherin levels. These results suggest SPC24 promotes osteosarcoma progression by increasing EGFR/Ras/ERK signaling.

Study design Retrospective comparative study. Objective To compare the outcomes of C1-C2 transarticular screw with C1 laminar hook (TAS + C1H) fixation and C1 trans-arch lateral mass screw with C2 pedicle screw (C1TLMS + C2PS) fixation in the treatment of reducible atlantoaxial dislocation (AAD). Summary of background data TAS + C1H is comparable to TAS with posterior wiring techniques and superior to C1 lateral mass screw combined with C2 pedicle screw (C1LMS + C2PS) in biomechanics. There were, however, few studies analyzing the differences in outcomes between TAS + C1H technique and modified C1LMS + C2PS technique (C1TLMS + C2PS) for treating AAD. Methods Data of 30 patients with reducible AAD treated by TAS + C1H fixation and another 30 cases treated by C1TLMS + C2PS fixation were retrospectively analyzed. Bone fusion time was recorded. The outcomes evaluated by American Spinal Injury Association impairment scale, visual analog scale score for neck pain, neck stiffness (none/mild/severe), patient satisfaction, and Neck Disability Index (NDI) were compared between two groups. Results There were no complications related to the surgical approach and instrumentation in either group. At the final follow-up, bone graft fusion rates were 100% in both the TAS + C1H fixation group and the C1TLMS + C2PS fixation group (P > 0.05). The neurological status evaluated by American Spinal Injury Association impairment scale were greatly improved in both screw-hook group (P 0.05). There were no significant differences between two groups in visual analog scale score for neck pain, neck stiffness, patient satisfaction, or Neck Disability Index (all P > 0.05). Conclusion C1TLMS + C2PS fixation was comparable to TAS + C1H fixation in fusion rate and functional outcomes for treating reducible AAD. To reduce the risk of vertebral artery injury, computed tomography scan, and reconstruction should be done to analyze vertebral artery course and C1-C2 anatomic structures before operation. Level of evidence 3.

Objective To evaluate differences in radiologic and functional outcomes between C1–C2 posterior temporary fixation (PTF) and cephalocervicothoracic cast fixation for type III odontoid fractures. Methods Data from 13 patients who underwent PTF and 13 cases who underwent cephalocervicothoracic cast fixation due to fresh type III odontoid fractures were reviewed retrospectively. All patients with fracture healing underwent a functional computed tomography scan at the final follow-up to evaluate the range of motion in C1–C2 rotation. Functional outcomes were evaluated in the form of visual analog scale for neck pain, neck stiffness, patient satisfaction, and Neck Disability Index. The outcomes were compared between the 2 groups. Results At the final follow up, all 26 patients achieved healing of their fractures. There were no complications associated with either treatment. The left-to-right ranges of motion of C1–C2 rotation were 41.9° ± 11.9° in the PTF group and 43.5° ± 12.0° in the cephalocervicothoracic cast fixation group. There was no statistical difference between the 2 groups regarding the C1–C2 rotation angle ( P > 0.05). There also were no significant differences between 2 groups in functional outcomes evaluated by visual analog scale for neck pain, neck stiffness, Neck Disability Index, and patient satisfaction (all P > 0.05). Conclusions The outcomes of PTF and cephalocervicothoracic cast fixation were comparable in the treatment of type III odontoid fractures. For type III odontoid fractures that cannot be managed by nonoperative fixation or anterior screw fixation, PTF may be the treatment of choice, because it spares the motion of the C1–C2 complex.

Tumor necrosis factor alpha (TNF-α)-induced osteoclastogenesis have profound effects in states of inflammatory osteolysis such as rheumatoid arthritis, periprosthetic implant loosening, and periodontitis. However, the exact mechanisms by which TNF-α promotes RANKL-induced osteoclast formation remains poorly understood. B lymphocyte-induced maturation protein-1 (Blimp1) is a transcriptional repressor that plays crucial roles in the differentiation and/or function of various kinds of cells including osteoclasts. A novel mechanism was identified where TNF-α-mediated Blimp1 expression, which contributed to RANKL-induced osteoclastogenesis. It is shown that TNF-α could promote the level of Blimp1 expression during osteoclast differentiation. Silencing of Blimp1 in osteoclast precursor cells obviously attenuated the stimulatory effect of TNF-α on osteoclastogenesis. Mechanistically, TNF-α-induced Blimp1 expression was markedly rescued by blocking the PI3K/Akt signaling pathway, which suggested that PI3K/Akt signaling was involved in the regulation of TNF-α-stimulated Blimp1 expression. Taken together, the results established a molecular mechanism of TNF-α-induced osteoclasts differentiation, and provided insights into the potential contribution of Blimp1 in the regulation of osteoclastogenesis by TNF-α. J. Cell. Biochem. 118: 1308-1315, 2017. © 2016 Wiley Periodicals, Inc.

Objective To analyze the clinical outcomes of our experience with the unilateral C2 translaminar screw technique and evaluate its feasibility as an alternative or salvage of the pedicle screw. Methods Eleven consecutive adult patients with atlantoaxial instability who underwent hybrid fixation techniques using unilateral translaminar screw combined with contralateral C2 pedicle screw and bilateral C1 LMS via posterior arch from January 2010 to December 2013 were retrospectively investigated. The surgical techniques and treatment procedures were described, and clinical symptoms, neurologic function, and imaging appearance were evaluated. Results The average age in our series was 40.9 years. No vascular or neurologic injuries occurred. No hardware failure or breach of C2 lamina or pedicle was observed in postoperative radiographs or computed tomography scans. Good bone union was achieved in all patients. There were no cases of screw pullout or pseudarthrosis. Conclusions Patients with variant vertebral artery or osseous anomaly are good candidates for the hybrid translaminar screw technique as an alternative to or salvage of C2 pedicle screw.

Study design A retrospective case series study with at least 10 years of follow-up data. Objective To validate the reliability of bilateral C1-2 transarticular screws and C1 laminar hooks and a bone autograft for acute pediatric atlantoaxial instability. Summary of background data The reliability of initial posterior atlantoaxial fusion in pediatric patients is still controversial. To date, however, only a few published articles with short-term follow-up data are available to help spinal surgeons understand the effects of posterior atlantoaxial fusion in the skeletally immature spine. Methods Five pediatric patients with acute atlantoaxial instability underwent atlantoaxial fusion using the above technique over a 3-year period. During a minimum 10-year follow-up period, not only outcomes and complications were investigated, but the vertical growth of the constructed spine in relation to the growth of the entire cervical spine, overall cervical spinal alignment, and adjacent-segment instability were evaluated. Results The clinical follow-up indicated solid fusion and complete clinical relief from symptoms. No neural or vascular impairment was observed. The radiological evaluation showed that all patients had growth within the fusion construct reaching a mean 35.4% of the entire cervical spine. There were no radiological indicators of subaxial instability, even when cervical sagittal alignments became straight with a mean C2-7 angle of 6.4°. Conclusion The results showed that initial posterior atlantoaxial fusion accomplished with bilateral C1-2 transarticular screws, C1 laminar hooks fixation, and bony autograft is a reliable surgical technique for treating acute pediatric atlantoaxial instability without negative effects on vertical growth at the fused level or the stability of the subaxial spine. Level of evidence 3.

To propose an independent radiological index to evaluate surgical outcomes of A type basilar invagination, a retrospective study was conducted to compare the clinical outcome between procedures 1 and 2 by applying intraoperative consistent traction and manual reduction. Moreover, the atlantodental interval (ADI), cervicomedullary angle (CMA), bilateral sagittal inclination of atlantoaxial joint (SIAA) were measured and compared to pre-operation. Postoperatively, only these patients undergoing procedure 2 achieved significant neurological improvement. The ADIs and the SIAAs decreased in both groups, these differences are statistically significant between pre- and post- operation. For postoperative CMAs, only these patients undergoing modified surgery gained significant improvement of angle with mean 141°. We concluded that the CMA or SIAA could be a radiological predictor to evaluate surgical outcome in BI, among which the CMA is a more independent and easily measurable predictor that is closely correlated with satisfactory neurological improvements. Moreover, procedure 2 with intraoperative resistant cranial traction and manual reduction can help us achieve a good CMA.

Objectives Retro-odontoid pseudotumor (ROP), with no rheumatoid arthritis, atlantoaxial instability, or other primary diseases, is defined as idiopathic retro-odontoid pseudotumor (IROP). Cervical spine degeneration is associated with IROP development. This study aims to evaluate the effect of cervical spine degeneration on the atlantoaxial complex and find the possible biomechanical mechanism of IROP development. Methods This study was performed using a three-dimensional (3D) finite element (FE) analysis. A degenerated FE model (FEM) and five operation FEMs (C1-C2 fusion, C0-C2 fusion, C0-C3 fusion, C0-C4 fusion, and C1 posterior arch resection) were established based on a normal 3D FEM of the cervical spine including C0-T1 with the main ligaments and muscles. The parameters, including the C1-C2 range of motions (ROMs) and odontoid-related ligaments’ stresses in degenerated and operation FEMs, were obtained and compared with those in normal FEM. Results Compared to normal FEM, degenerated FEM had reduced C3-C7 ROMs and increased C1-C2 ROMs and odontoid-related ligaments’ stresses. After internal fixation, C1-C2 ROMs and most odontoid-related ligaments’ stresses were greatly decreased, but with no significant differences among C0-C2, C0-C3, C0-C4, and C1-C2 fusion models. For the C1 posterior arch resection model, C1-C2 ROMs and most odontoid-related ligaments’ stresses increased, compared with normal FEM. Conclusions Cervical spine degeneration plays an important part in IROP development in biomechanics. Atlantoaxial complex compensates for cervical spine degeneration, with increased C1-C2 ROMs and odontoid-related ligaments’ stresses. Atlantoaxial fusion or short segmental occipitocervical fusion can effectively reduce the stress and should be considered in IROP treatment.

Objective To develop modified finite element models to simulate degenerative lumbar scoliosis (DLS) based on the normal lumbar spine model and to investigate the facet joint force of the DLS. Methods A 3-dimensional finite element model of a normal lumbar spine was modified to simulate 3 different Cobb angles conditions (12.3°, 22.2°, and 31.8°). The stresses on the facet joint were calculated on both sides (right and left) of the each vertebra. Changes of stress and asymmetry in contact forces between facet joints in the development of DLS were quantitatively analyzed to better understand the development of DLS and the biomechanical forming mechanism. Results The results show that asymmetric responses of the facet joint forces exist in various postures and that such effect is amplified with larger curve. When the Cobb angle was smaller, the convex side of the facet joints suffered larger force. When the Cobb angle was larger than 20°, the concave side of the facet joints suffered larger force. In the axial-rotation cases, the facet joint compression is less often located on the ipsilateral side than the contralateral side at the same level. Conclusions With the asymmetric loading, facet joints compressive deformation appears on the concave side, and it decreases in the effect of the facet joints to limit the vertebral rotation and listhesis. Asymmetric loading on facet joint contact forces accelerates asymmetry in the lumbar spine.

The purpose of this study was to evaluate the association between lumbar spine facet joint orientation and tropism, sagittal spinopelvic alignment, and rotational deformity, identified by radiographic and computed tomography (CT) measurements, in degenerative lumbar scoliosis (DLS). Standing whole-spine sagittal radiographs and CT scans, including the pelvis, were performed and analyzed in 60 DLS patients (16 males, 44 females; mean age 65 years). Cobb angle, pelvic incidence (PI) and lumbar lordosis (LL) were measured on standing lumbar radiographs. Facet joint orientation on both sides at L3/4, L4/5, and L5/S1 was determined from transverse-plane CT. Facet joint tropism was defined as a difference in symmetry of more than 10 degrees between the orientations of the facet joints. There were significant differences in the incidence of facet joint tropism between the two groups at L3/4, L4/5, and L5/S1 (P = 0.011, P = 0.043, and P = 0.004, respectively). LL was significantly smaller in type II DLS (P = 0.049). Facet joint orientation, pelvic incidence, and Cobb angle did not differ between groups. No significant correlation between LL and PI was observed in either group. This study provides a reliability analysis of rotational deformity in patients with DLS. In conclusion, we observed a significant relationship between facet joint tropism and rotational deformity in patients with DLS. Furthermore, the different types of DLS demonstrated significant differences in LL that may induce spinal symptoms.

To evaluate the outcome of posterior open reduction and interlaminae compression fusion using a screw-rod system combined with a structural iliac bone graft in the treatment of atlantoaxial dislocation (AAD) secondary to os odontoideum.A retrospective study was performed on 24 patients with AAD secondary to os odontoideum. All cases were with partial reduction after skeletal traction. Intraoperative open reduction and fixation were performed with a posterior screw-rod system, followed by interlaminae compression of an autologous iliac bone graft for fusion. The modified atlanto-dental interval (MADI) was measured to assess the degree of dislocation before traction, after traction, and postoperatively. Japanese Orthopaedic Association (JOA) score, Nurick scale score, visual analog scale score for neck pain (VASSNP), Neck Disability Index (NDI) score, and neck stiffness were used to evaluate functional outcomes.The mean duration of follow-up was 43.0 ± 24.0 months. All patients achieved relief of symptoms and solid bone fusion. There were no complications associated with instrumentation and operation. At the final follow-up, the average MADI was reduced to 2.0 ± 0.8 mm (pretraction: 9.2 ± 1.1 mm; post-traction: 6.6 ± 0.7 mm; P 0.001). The neck stiffness was significantly relieved (P 0.001), and function of the spinal cord manifested by the JOA score and Nurick scale score significantly improved (all P0.001). The NDI score and VASSNP markedly decreased (all P0.001).Intraoperative open reduction and interlaminae compression fusion using a posterior screw-rod system combined with a structural iliac bone graft is a safe and effective procedure for AAD secondary to os odontoideum.

Background Posterior C1-C2 temporary-fixation technique can spare the range of motion (ROM) of the atlantoaxial joint after odontoid fracture healing. However, few studies analyze the difference in clinical outcome between this technique and posterior C1-C2 fusion technique for new odontoid fracture. Objective To verify whether the clinical outcome of the posterior C1-C2 temporary-fixation technique is superior to that of the posterior C1-C2 fusion technique in the treatment of a new odontoid fracture. Methods Twenty-one of 22 patients who underwent posterior C1-C2 temporary fixation of an odontoid fracture achieved fracture healing and regained motion of the atlantoaxial joint. The functional outcomes of these 21 patients were compared with that of a control group, which consisted of 21 randomly enrolled cases with posterior C1-C2 fixation and fusion. The differences between the 2 groups in the visual analog scale score for neck pain, neck stiffness, Neck Disability Index, 36-Item Short Form Health Survey, and time to fracture healing were analyzed. Results Significantly better outcomes were observed in the temporary-fixation group for visual analog scale score for neck pain, Neck Disability Index, and neck stiffness. The outcomes in the temporary-fixation group was superior to those in the fusion group in all dimensions of the 36-Item Short Form Health Survey. There were no significant differences in fracture healing rate and time to fracture healing between the 2 techniques. Conclusion Functional outcomes were significantly better after posterior C1-C2 temporary fixation than after fusion. Temporary fixation can be used as a salvage treatment for an odontoid fracture with an intact transverse ligament in cases of failure of, or contraindication to, anterior screw fixation.

Retrospective comparative study.To compare the outcomes of C1-C2 transarticular screw combined with C1 laminar hook (TAS+C1H) and C1-C2 transarticular screw combined with modified Gallie technique (TAS+G) for treating reducible atlantoaxial dislocation (AAD).Both TAS+C1H and TAS+G fixation were 3-point fixation techniques for AAD. TAS+C1H technique was comparable to TAS+G technique in biomechanics. However, it is unknown whether it can achieve same outcomes as TAS+G technique.Data of the 63 patients who underwent TAS+C1H or TAS+G fixation and fusion because of AAD were retrospectively reviewed. Bone fusion time was recorded. The outcomes evaluated by visual analog scale score for neck pain (VASSNP), Nurick scale, neck stiffness (none/mild/severe), patient satisfaction, and Neck Disability Index (NDI) were compared between two groups.At the final follow-up, bone graft fusion rates were 100% in both groups (P 0.05). Nurick scales were significantly improved in both groups (P 0.05), but with no significant differences between groups (P 0.05). There were no significant differences between two groups in VASSNP, neck stiffness, patient satisfaction, or NDI (all P 0.05). There were no complications related to the surgical approach and instrumentation in either group.Both TAS+C1H and TAS+G fixation were effective in the treatment of reducible AAD. TAS+C1H was safer than TAS+G because it could potentially reduce the risk of spinal cord and venous plexus injury associated with sublaminar cables.3.

This chapter describes the basic principle of translational medicine and its application to the posterior “hook-nail” atlantoaxial fixation technique.

Study design A retrospective case series. Objective To describe a novel intraoperative reduction technique applying C1 transposterior arch lateral mass screw combined with C2 pedicle screw and rod system for pediatric acute atlantoaxial rotatory subluxation with injury of transverse ligament and evaluate outcomes of this technique. Summary of background data For atlantoaxial rotatory subluxation with disruption of transverse ligament or recurrent cases, initial posterior atlantoaxial fusion is a preference. It is an important prerequisite for successful surgery to achieve satisfactory reduction of atlantoaxial articulation after preoperative cranial traction. However, the placement of cranial tractor and persistent traction may be challenging due to a pediatric patient's noncompliance and unsuitable anatomic structure. Therefore, an intraoperative way to achieve reduction and to keep solid stability with only a single procedure is needed. Methods The consecutive patients with atlantoaxial rotatory subluxation with injury of transverse ligament, including 4 males and 1 female, underwent intraoperative reduction and fixation applying C1 posterior arch lateral mass screw combined with C2 pedicle screw and rod system during a 2-year period. The surgical technique and procedure of treatment were intensively reviewed; the clinical outcomes were retrospectively investigated in the aspects of clinical symptoms and imaging appearance. Results Clinical follow-ups were obtained for an average of 29.4 (range, 24-30 mo) months. The clinical and radiological follow-up indicated a complete clinical relief and satisfactory reduction, stable arthrodesis of atlantoaxial articulation. No neural and vascular impairment related to this technique were observed. Conclusion The primary outcome showed under sufficient preoperative imaging measurements, C1 transposterior arch lateral mass screw combined with C2 pedicle screw and rod system that obviated preoperative cranial traction provided reliable reduction and stability of atlantoaxial articulation for atlantoaxial rotatory subluxation with injury of transverse ligament. Level of evidence 4.

STUDY DESIGN A prospective study. OBJECTIVE To evaluate the outcomes of posterior reduction and temporary fixation using the C1-C2 screw-rod system for odontoid fracture unsuitable for anterior screw fixation. SUMMARY OF BACKGROUND DATA Anterior screw fixation has become the most widely used surgical procedure for the stabilization of odontoid fractures. However, if there is any contraindication for anterior fixation, posterior atlantoaxial fusion is preferred, eliminating the normal rotation of the atlantoaxial complex. METHODS A consecutive series of 22 patients with odontoid fracture unsuitable for anterior screw fixation were involved in this study. Posterior reduction and fixation without fusion using the C1-C2 screw-rod system was performed. Once fracture healing was obtained, instrumentation was removed. The visual analogue scale of neck pain, neck stiffness, American Spinal Injury Association impairment scale, patient satisfaction, and neck disability index were recorded. The range of motion of C1-C2 in flexion-extension and rotation was calculated. RESULTS The average age at internal fixation surgery was 40.2±11.3 years. The mean duration of follow-up was 41.8±26.8 months. There were no complications associated with instrumentation. All patients returned to their preoperative work. Fracture healing was observed in 21 patients and the instrumentation was removed. After removing the instrumentation, the visual analogue scale was reduced and neck stiffness were relieved (all P

A retrospective clinical study was conducted and related literatures were reviewed.This study aimed to evaluate outcome of multilevel anterior cervical discectomy and fusion with plate fixation for juvenile unilateral muscular atrophy of the distal upper extremity accompanied by cervical kyphosis.Juvenile unilateral muscular atrophy of the distal upper extremity is a rare disease. Traditional treatment uses a neck collar to immobilize neck motion. However, if the disease is accompanied by cervical kyphosis, conservative treatment is difficult to correct cervical kyphosis and the prognosis is worsened. Therefore, it is important to initially apply surgical treatment for juvenile unilateral muscular atrophy accompanied with cervical kyphosis.From March 2008 to May 2010, 4 patients were transferred to our spine medical center because of a history of slowly progressive distal weakness and atrophy of their hands and forearms. Four patients were diagnosed with Hirayama disease accompanied with cervical kyphosis based on their clinical representations and radiologic findings. After conservative treatment failed, these patients underwent multilevel anterior cervical discectomy and fusion with plate fixation. The clinical outcomes were retrospectively evaluated with follow-up ranging from 1.5 to 3 years.The clinical and radiologic follow-up indicated satisfactory clinical relief from symptoms, cervical sagittal alignment and cervical spinal canal volume, for all the patients. Within 6 months after surgery, the JOA score improved from a preoperative average of 14 to a postoperative average of 16.3; JOA recovery rates of all patients were more than good level. The muscle strengths of intrinsic muscles, wrist flexors and extensors, and biceps and triceps muscle improved on average by 1 grade. No complications occurred.Hirayama disease is a rare disease, a proper diagnosis of which can be made based on significant clinical symptoms and neurological imaging (dynamic MRI). The primary results from this study showed the tendency that multilevel anterior cervical discectomy and fusion with plate fixation is a preferred treatment for patients showing anterior effacement and apparent cervical kyphosis.

Objectives To analyze whether multifidus degeneration has a relationship with degenerative lumbar spinal stenosis (LSS). Materials and methods Clinical data of 40 patients with LSS were analyzed retrospectively. Moreover, 40 healthy people were selected as controls. Subjects of both groups underwent a 1.5-T lumbar spinal magnetic resonance imaging scan in our hospital, and then the multifidus muscularity, fatty infiltration ratio, and bilateral asymmetry at L4/5 level on magnetic resonance imaging were measured with ImageJ software to analyze and compare the multifidus parameters between the 2 groups. Results Compared with the control group, the multifidus muscularity was lower, fatty infiltration ratio was greater, and muscle asymmetry was more significant at the L4/5 level in patients with LSS, and the difference between the 2 groups was statistically significant. Conclusions Multifidus degeneration, including reduced volume, increased fatty infiltration, and bilateral muscle asymmetry, has an association with LSS.

To analyze the effect of T1-slope (T1S) on sagittal alignment of the subaxial cervical spine after posterior C1-C2 fusion.The data of 35 consecutive patients who underwent posterior C1-C2 fusion due to atlantoaxial instability with os odontoideum were retrospectively reviewed. Radiographic parameters, including T1S, C1-C2 angle and C2-C7 angle, were measured before operation and at the final follow-up. Patients were divided into 2 groups: high T1S group and low T1S group. Differences within and between groups in radiographic parameters and the relationships among T1S, C1-C2 angle and C2-C7 angle were analyzed.After operation, C1-C2 angle was significantly enlarged (P0.05) while C2-C7 angle reduced (P0.05). However, significant change was not observed in T1S (P0.05). Postoperative C2-C7 angle had a medium positive relation with both preoperative (r=0.563, P0.05) and postoperative T1S (r=0.547, P0.05). C1-C2 angle was negatively related to C2-C7 angle before operation (r=-0.590, P0.05) but not after operation (r=-0.125, P0.05). However, change of C1-C2 angle demonstrated a medium negative relation with change of C2-C7 angle after operation (r=-0.614, P0.05). When the patients were divided into high and low T1S groups, there were significant difference in both preoperative and postoperative C2-C7 angles between 2 groups (all P0.05) but not in C1-C2 angle, change of C1-C2 angle or change of C2-C7 angle (all P0.05). After operation, C1-C2 angles became larger in both groups (all P0.05). Meanwhile, although postoperative C2-C7 angle became smaller than preoperative one in both groups, statistical difference was only observed in high T1S group (P0.05).T1S was a useful parameter to evaluate postoperative alignment of the subaxial cervical spine after posterior C1-C2 fusion. To avoid postoperative misalignment of the subaxial cervical spine, C1-C2 should be fixed in less lordosis, especially in patients with high preoperative T1S.

Breast cancer is the most common cause of cancer death in women and ranks second among cancer deaths. Metastasis is the main cause of death in breast cancer patients. However, the mechanisms underlying the invasion and metastasis of breast cancer cells remain largely elusive. Here we report that the protein PRAME, a tumor-associated antigen isolated from a melanoma, plays a role in preventing the proliferation and metastasis of breast cancer cells. Knocking down of PRAME promotes breast cancer cell proliferation and inhibits apoptosis. In addition, inhibition of PRAME promotes the invasion of breast cancer cells. To further examine the role of PRAME in vivo, we utilized mouse model and found the volume and the weight of tumors was markedly increased after PRAME was knocked down. This study demonstrates that PRAME functions as a tumor suppressor in breast cancer.

To compare the results of anterior cervical discectomy and fusion (ACDF) combined with anterior cervical foraminotomy (ACF) and standalone ACDF for the treatment of cervical spondylotic radiculopathy (CSR).The data of 24 consecutive patients who underwent ACDF combined with ACF for significant bony foraminal stenosis were reviewed. The clinical outcomes, including visual analog scale (VAS) scores for neck pain and arm pain and Neck Disability Index, were evaluated by questionnaires. Radiologic outcomes as manifested by C2-7 angle and surgical segmental angle were recorded. The outcomes were compared with outcomes of standalone ACDF for CSR secondary to posterolateral spurs.At the final follow-up evaluation, all patients obtained bone fusion. No patient developed adjacent segment disease. Operative time was longer and blood loss was more in the ACDF combined with ACF group than in the ACDF group (all P0.05). However, in both groups, the neck VAS score, arm VAS score, and Neck Disability Index were significantly reduced postoperatively (all P0.05). The segmental curve and C2-7 lordosis were significantly improved postoperatively (all P0.05). There was no significant difference between the 2 groups in clinical and radiologic outcomes (P0.05).For CSR with foraminal stenosis secondary to significant bony pathology that cannot be managed with standalone ACDF, ACDF combined with ACF is an effective and safe treatment strategy.

To evaluate the outcomes of anterior approach for cervical spine fractures at C5-T1 in patients with ankylosing spondylitis (AS) and study the problems encountered in diagnosis and treatment.Ten patients with AS (all males; mean age 43.7±9.4 years) underwent anterior surgeries to treat fractures at C5-T1. Skull tractions were performed on patients with fracture dislocation preoperatively. After operation, all the patients wore a cervical collar for 3 months. Plain radiographs at follow-up were reviewed. If bone fusion could not be confirmed on plain radiograph, CT scan was employed. The pre- and postoperative neurological statuses were evaluated according to the Frankel grading system. Problems encountered in diagnosis and treatments were analyzed.The mean follow-up was 41.2±22.7months. After operation, the displacements of fractures were significantly reduced(P0.05). Bone fusions were observed in 9 patients at final follow-up. Frankel grades improved by 1.0±0.7 grade (P0.05). Posterior complications occurred in four patients, including implants failure (n=1), subsidence of cage (n=1), hoarse voice (n=1) and pneumonias (n=2). The patient with implants failure required revision surgery and anterior-posterior fixation. Patient with subsidence of the titanium cage achieved bone fusion with prolonged cervical collar immobilization.The diagnosis and treatment of cervical spine fractures at C5-T1 in AS patients are challenging, with high risk of neurological compromise and postoperative complications. The single anterior approach followed by postoperative immobilization with a cervical collar can yield acceptable results if the cases are properly selected.

To evaluate the acute stability of a novel integrated C1 laminar hook (H) combined with a C1-C2 transarticular screw (TAS) with established techniques.A novel integrated C1 laminar hook was tested. Seven human cadaveric cervical spines (C0-C3) were used. The range of motion (ROM) of C1-C2 during flexion-extension, lateral bending, and axial rotation were recorded. The specimens were tested under the following conditions: intact, destabilized (using a type II odontoid fracture model), and destabilized but with internal fixation. The following screw systems were used: bilateral C1-C2 TAS combined with the Gallie (G) technique (TAS+G), C1-C2 TAS combined with a novel integrated C1 laminar hook (TAS+H), C1 lateral mass screw and C2 pedicle screws (C2PS+C1LMS), and novel integrated C1 laminar hook combined with C2 pedicle screws (C2PS+H). The TASs were always inserted after the C2PSs. The C2PS+C1LMS and C2PS+H tests were performed alternatively, as were the TAS+G and TAS+H tests.All fixation constructs greatly improved acute atlantoaxial stability, with no significant difference among TAS+H, TAS+G, and C2PS+C1LMS (all P0.05). C2PS+H showed the greatest C1-C2 ROM in axial rotation, significantly different from TAS+G, C2PS+C1LMS, and TAS+H fixation models (all P0.05). However, there were no significant differences between C2PS+H and the other 3 models in flexion-extension and lateral bending (all P0.05).The TAS+H technique can achieve acute stability comparable to that with the TAS+G technique for treating C1-C2 instability. The C2PS+H is a promising alternative, although it provides less stability in axial rotation than TAS+G, TAS+H, or C2PS+C1LMS.

To verify the relationship between neurologic deficit after spinal cord injury without radiologic evidence of trauma (SCIWORET) and coexisting cervical disc herniation (CDH). A retrospective review was made to compare the neurologic and radiological outcomes in SCIWORET patients with and without CDH. The neurologic deficit was evaluated by the American Spinal Injury Association (ASIA) scale at admission and last follow-up. The radiological evaluation was performed with magnetic resonance imaging to determine the maximum canal compromise (MCC) and maximum spinal cord compression (MSCC). Prevalence of CDH was 37.1 % among all 70 SCIWORET cases. There was no significant difference between the CDH and non-CDH group in the ASIA grade at admission and last follow-up and the improvement. Patients with CDH had more substantial MSCC (P

The purpose of the current study was to determine, whenever the patients complained of probable symptoms of discogenic low back pain and had obvious disc pathological changes on magnetic resonance imaging (MRI) but showed negative in discography, whether we could absolutely exclude the diagnosis of discogenic pain or not.The patients we selected in our study had only one segmental disc pathology on MRI for the purpose of minimizing the interference and all patients complained of probable discogenic pain symptoms. Some special lumbar diseases were excluded by physical examination and CT or MRI scan. Finally, 45 isolated patients with negative discography were enrolled in our study from January 2006 to June 2008. Twenty-three patients were randomly distributed in experimental group, who underwent provocative discography plus intradiscal injection of dexamethasone (5 mg in each patient), while the other 22 patients in the control group received intradiscal injection of saline as a placebo. Visual analog scale (VAS) and Oswestry Disability Index (ODI) were used to evaluate the changes of pain and function after discography.The mean age of the 16 male and 29 female patients was 44.9 years, whose main clinical manifestations included axial back pain (100%), pain in the region of Groin (33.3%), pain in the anterior or posterior region of thigh (42.2%), buttock pain (24.4%) and lower extremity pain (11.1%), and among them L3-L4 pathological disc was found in three patient, L4-L5 pathological disc in 28 patients and L5-S1 pathological disc in 14 patients. Discography and CT scans of the 45 patients revealed that there were grade 5 in 38 discs and grade 4 in seven discs by means of Modified Dallas classification. After about 6-month follow-up, the results showed that VAS scores and ODI scores were greatly improved during the first 3-month follow-up in the experimental group compared with pre-discography and between groups (p0.05), but no statistically significant difference after 24-week follow-up (p0.05). The probable symptoms of discogenic low back pain were significantly improved in the experimental group in the short term.The study indicated that negative discography in patients with probable symptoms of discogenic low back pain cannot absolutely exclude the diagnosis of discogenic pain. Patients of this kind may suffer from other diseases, but we cannot ignore the existence of discogenic pain.

STUDY DESIGN A retrospective comparative study. OBJECTIVE The aim of this study was to compare the outcomes of anterior screw fixation and posterior temporary-fixation in the treatment of Anderson-D'Alonzo type II odontoid fractures. SUMMARY OF BACKGROUND DATA Posterior C1-C2 temporary-fixation can spare the motion of C1-C2 in the treatment of odontoid fractures. However, it is unknown whether it can achieve the same outcomes as anterior screw fixation. METHODS Data of 20 patients who underwent posterior temporary-fixation due to Anderson-D'Alonzo type II odontoid fractures with intact transverse ligament were retrospectively reviewed. Another 20 patients undergoing anterior screw fixation were randomly selected as the control group. The range of motion (ROM) in rotation of C1-C2 measured on functional computed tomography (CT) scan and outcomes evaluated by the visual analog scale (VAS) for neck pain, neck stiffness, patient satisfaction, and neck disability index (NDI) were compared between two groups at the final follow-up. RESULTS At the final follow-up, 19 cases in each groups achieved facture healing. Total C1-C2 ROM in rotation on both sides in the posterior temporary-fixation group was 32.4 ± 12.5°, smaller than 40.0 ± 13.0 in the anterior fixation group. However, there was no statistical difference between two groups. And there was no significant difference between two groups in functional outcomes evaluated by VAS for neck pain, neck stiffness, patient satisfaction, and NDI. CONCLUSION Posterior temporary-fixation can spare the motion of C1-C2 and achieve same good clinical outcomes as anterior screw fixation in the treatment of Anderson-D'Alonzo type II odontoid fractures. It was an ideal alternative strategy to anterior screw fixation. LEVEL OF EVIDENCE 3.