Missed manubriosternal dislocation in patient with thoracolumbar fracture, a case report.

BACKGROUND: Spine fractures combined with sternal injury are most commonly occur in the thoracic region. Lower cervical and thoracolumbar injuries have also been reported, especially for the patients with manubriosternal dislocation. The type of spine injury is easily recognized in initial presentation, but we may miss the sternal fracture and manubriosternal dislocation. CASE PRESENTATION: A 23-year-old male patient complained with chest, right ankle, and lumbar pain after a fall at ground level, with diagnosis of right distal tibial fracture, sternal fracture, calcaneus fracture, and L2 vertebral fracture. However, neurologically he was completely normal. He underwent the operation for his lower extremity and spine, but we missed his manubriosternal dislocation after discharged. After one month, he came to the clinic with complained of chest pain, the imaging exams showed anterior dislocation of manubriosternal joint. We chose conservative treatment for manubriosternal dislocation. He was followed up at monthly intervals and radiographs along with computerized tomography showed satisfactory in fracture healing of lumber and the sternal fracture. However, the manubriosternal dislocation was malunioned. The patient had appearance deformity of the manubriosternal joint. CONCLUSION: This case supports the concept of the existence and clinical relevance of the thoracic cage theory, the thoracolumbar vertebrae should also be included in the thoracic cage theory.

Surgical treatment of compressive spinal hemangioma : A case series of three patients and literature review.

PURPOSE: In this article we describe the treatment of compressive vertebral hemangioma. METHODS: Our case series comprised three patients with aggressive hemangioma. We performed a combination of posterior decompression and vertebroplasty for the two patients with a sacral hemangioma and a thoracic hemangioma, and en bloc resection for the third patient, who also had a thoracic lesion. RESULTS: Surgical intervention is indicated in cases of rapidly progressive tumors or severe myelopathy. All three patients had good clinical results. The follow-up period ranged from 8 to 56 months. The mean blood loss was around 700 ml, and mean surgical time was 2.1 h. Blood loss for the en bloc procedure was around 1,200 ml, and surgical time was 2.3 h. CONCLUSION: A combination of posterior decompression, vertebroplasty, and posterior fixation for aggressive hemangioma can reduce blood loss during surgery. For patients with hemangioma and with incomplete paralysis, total en bloc spondylectomy should be considered. Adjuvant radiotherapy can reduce the recurrence of cavernous vertebral hemangiomas.

Anterior transpedicular screws in conjunction with plate fixation and fusion for the treatment of subaxial cervical spine diseases.

OBJECTIVE: This study aimed at exploring the clinical application of anterior transpedicular screw (ATPS) and plate in the reconstruction of subaxial cervical spine. METHODS: 8 cases were reconstructed by ATPS and plate in the subaxial cervical spine from Jan 2009 to Dec 2011. X-rays and computed tomography images were collected to evaluate the position of ATPS. Magnetic resonance imaging was also included to evaluate the result of decompression, the existence of epidural hematoma and the morphology of the cervical spinal cord. Japanese Orthopaedic Association scores were observed before and after operation as a functional estimation. RESULTS: All of the eight cases were followed up from 3 to 36 months with the average of 15.5 months. A total of 16 ATPS were implanted in the subaxial cervical spine in the eight patients. All the screws were inserted smoothly. Bone fusion was found in all the subjects 4.5 months after operation on average. No loosening or breakage of the internal fixation was observed in our study. Hoarseness was observed in one case due to distraction injury of the recurrent laryngeal nerve, which disappeared after 3 weeks' conservative treatment. Dysphagia was complained by two patients after surgery, which was alleviated 3 months later. There were four screws deviating less than 1 mm (Grade 1), two medially and two laterally. All the anterior compressions were removed completely in this group. Only a small amount of epidural hematoma was found in four cases on MRI images before discharge. The average JOA scores were significantly improved from 5.6 ± 1.4 before surgery to 14.5 ± 0.8 at discharge (P < 0.01), which decreased to 13.2 ± 1.2 at 3 months after operation, but improved again to 15.2 ± 0.8 at 1 year after operation. CONCLUSION: Although there are some complications, ATPS with plate is an effective and safe technique for anterior reconstruction in the subaxial cervical spine. Only those spine centers with sufficient experience in complex cervical spine reconstruction surgery can conduct this technique according to strict indications.

Biomechanical evaluation of a novel atlas polyaxial transverse connecting screw system, an in vitro human cadaveric study.

PURPOSE: To introduce a novel transverse connecting screw system, and to evaluate the biomechanical stability of the novel screw system using human cadaveric specimens. METHODS: Six fresh-frozen cadaveric upper cervical spines were used in our study. Every specimen was tested under 5 conditions: intact group; unstable group; C1 to C2 screw rod system group; C1 to C2 + crosslink system group; atlas polyaxial transverse connecting screw (APTCS) system. RESULTS: Compared with the intact state, C1 to C2 screw rod system, C1 to C2 + CL system and APTCS showed statistically decrease range of motion in all directions except for the unstable group under posterior extension direction (P < .05). APTCS group has the least range of motion in all directions (P < .001). CONCLUSION: The APTCS system was able to restore stability to the atlantoaxial joint. APTCS system has the advantages of easy installation, convenient bone grafting, and strong biomechanical strength.

Field assessment of Bt cry1Ah corn pollen on the survival, development and behavior of Apis mellifera ligustica.

Honeybees may be exposed to insecticidal proteins from transgenic plants via pollen. An assessment of the impact of such exposures on the honeybee is an essential part of the risk assessment process for transgenic Bacillus thuringiensis corn. A field trial was conducted to evaluate the effect of transgenic Bt cry1Ah corn on the honeybee Apis mellifera ligustica. Colonies of honeybees were moved to Bt or non-Bt corn fields during anthesis and then sampled to record their survival, development and behavior. No differences in immature stages, worker survival, bee body weight, hypopharyngeal gland weight, colony performance, foraging activity or olfactory learning abilities were detected between colonies that were placed in non-Bt corn fields and those placed in Bt corn fields. We conclude that cry1Ah corn carries no risk for the survival, development, colony performance or behavior of the honeybee A. mellifera ligustica.

Reliability and repeatability of a modified thoracolumbar spine injury classification scoring system.

Purpose: On the basis of the Thoracolumbar Injury Classification and Severity Score (TLICS), an modified TLICS classification system was presented, its reliability and repeatability were assessed, and the factors influencing classification consistency were examined. Methods: Five spinal surgeons were chosen at random. The clinical data of 120 patients with thoracolumbar fractures admitted to the Department of Spine Surgery, Ningbo Sixth Hospital from December 2019 to June 2021 were categorized using the modified TLICS system. After 6 weeks, disrupt the order of data again. Using unweighted Cohen's kappa coefficients, the consistency of the modified TLICS system was assessed in five aspects: neurofunctional status, disc injury status, fracture morphology, posterior ligament complex (PLC) integrity, and treatment plan. Results: In terms of reliability, the average kappa values for the subclasses of the modified TLICS system (neurofunctional status and disc injury status) were 0.920 and 0.815, respectively, reaching the category of complete confidence. Fracture morphology and treatment plan had average kappa values of 0.670 and 0.660, respectively, which were basically reliable. The average kappa value of PLC integrity was 0.453, which belonged to the category of moderate confidence. The average kappa coefficients of each subcategory (neurological status, disc injury status) had excellent consistency, and the kappa values were 0.936 and 0.879, respectively, which belonged to the completely credible category. The kappa values of fracture morphology and treatment plan repeatability were 0.772 and 0.749, respectively, reaching the basic credibility category. PLC integrity repeatability kappa value is low, 0.561, to moderate credibility category. Conclusion: The modified TLICS system is intuitive and straightforward to understand. The examination of thoracolumbar fracture injuries is more exhaustive and precise, with excellent reliability and repeatability. The examination of neurological status and disc injury status is quite reliable and consistent. The consistency of fracture morphology is slightly poor, which is basically credible; the PLC integrity consistency is poor, reaching a reliability level of moderate, which may be associated with the subjectivity of clinical evaluation of PLC.

Posterior temporary fixation of C1-C2 screw-rod system for unstable C1 burst fracture.

Whether an unstable C1 burst fracture should be treated surgically or conservatively is controversial. The purpose of this study is to evaluate the effectiveness and motion-preserving function of temporary fixation of C1-C2 screw-rod system for the reduction and fixation of unstable C1 burst fracture. We retrospectively reviewed 10 patients who were treated with posterior C1-C2 temporary fixation without fusion. We assessed age at surgery, gender, pre- and postoperative visual analog scale (VAS), Neck Disability Index (NDI), atlanto-dens interval (ADI), lateral mass distance (LMD), and rotation function of C1-C2 complex. Six males and 4 females were included in our study. The average follow-up duration was 14.1 ± 1.37 months. The left-to-right ROMs of C1-C2 rotation was 9.6° ± 1.42°. The preoperative cervical VAS was 8.30 ± 0.48; the postoperative cervical VAS of C1-C2 fusion was 2.90 ± 0.57. The preoperative VAS for removal was 2.0 ± 0.00, and the postoperative VAS for removal was 2.3 ± 0.48. The preoperative cervical NDI was 81.40% ± 2.07%, the postoperative cervical NDI of C1-C2 fusion was 18.10% ± 1.52%. The preoperative NDI for removal was 15.9% ± 1.20%. The postoperative NDI for removal was 14.5% ± 1.08%. The preoperative ADI was 4.43 ± 0.34 mm, and postoperative ADI was 1.94 ± 0.72 mm. The preoperative LMD was 6.36 ± 0.58 mm, and postoperative LMD was 1.64 ± 0.31 mm. Posterior temporary C1-C2 fixation can achieve a good fusion and satisfied reduction of C1 fracture, relieve the pain, improve the cervical function outcome, but may reduce the rotational range of motion of C1-C2. Posterior C1-C2 temporary fixation without fusion was not suitable for C1 burst fracture. We recommend permanent C1-C2 fixation and fusion for C1 burst fracture if surgery is necessary.

Contralateral radiculopathy after unilateral transforaminal lumbar interbody fusion: causes and prevention.

BACKGROUND: Unilateral transforminal lumbar interbody fusion (TLIF) with a single cage can provide circumferential fusion and biomechanical stability. However, the causes and prevention of contralateral radiculopathy following unilateral TLIF remain unclear. METHODS: In total, 190 patients who underwent unilateral TLIF from January 2017 to January 2019 were retrospectively reviewed. Radiological parameters including lumbar lordosis, segmental angle, anterior disc height, posterior disc height (PDH), foraminal height (FH), foraminal width, and foraminal area (FA) were measured preoperatively and postoperatively. Preoperative and postoperative visual analog scale scores were also recorded. RESULTS: The incidence of contralateral radiculopathy after unilateral TLIF was 5.3% (10/190). The most common cause was contralateral foraminal stenosis. Unilateral TLIF could increase the lumbar lordosis, segmental angle, and anterior disc height but decrease the PDH, FA, and FH in patients with symptomatic contralateral radiculopathy. The intervertebral cage should be placed to cover the epiphyseal ring and cortical compact bone of the midline, and the disc height can be increased to enlarge the contralateral foramen. CONCLUSION: The most common cause of contralateral radiculopathy is contralateral foraminal stenosis. Careful preoperative planning is necessary to achieve satisfactory outcomes. Improper unilateral TLIF will decrease the PDH, FA, and FH, resulting in contralateral radiculopathy.

[Minimally invasive direct lateral approach debridement, interbody bone grafting, and interbody fusion combined with posterior percutaneous pedicle screw fixation for lumbar spinal tuberculosis].

OBJECTIVE: To investigate the clinical efficacy and superiority of direct lateral interbody fusion combined with posterior percutaneous screw fixation in the treatment of lumbar tuberculosis. METHODS: From June 2013 to August 2016, the clinical data of 83 patients with lumbar tuberculosis were retrospectively analyzed, including 55 males and 28 females, aged from 27 to 72 (49.5±13.5) years. These 83 patients were divided into two groups according to different operation methods, 35 cases in group A were treated with direct lateral interbody fusion combined with posterior percutaneous screw fixation;48 cases in group B were treated with anterior traditional extraperitoneal debridement combined with posterior internal fixation. After operation, regular quadruple antituberculosis drugs were continued for 18 months. The operation time, intraoperative blood loss, hospital stay, bone graft fusion time and complications were compared between the two groups. Visual analogue score (VAS) of lumbar pain, Oswestry Disability Index (ODI), sagittal Cobb angle, erythrocyte sedimentation rate (ESR) and C-reactive protein(CRP) values before and after operation were analyzed. RESULTS: The operation was successfully completed in both groups, and the operation mode was not changed during operation. The operation time, intraoperative blood loss and hospital stay were (149.4±13.3) min, (354.3±69.0) ml, (9.4±1.6) d in group A and(116.8±10.0) min, (721.9±172.3) ml, (11.8±1.7) d in group B, respectively, with significant difference between the two groups (P<0.05). The follow up time was (24.2±5.1) months in group A and (24.0±5.0) months in group B, there was no significant difference between two groups (P>0.05). At the follow-up of 4 months after operation, one patient in group A was found to have enlarged psoas major abscess on the contralateral side, and was cured after secondary operation. No sinus formation, cerebrospinal fluid leakage, internal fixation loosening, fracture or distal junction kyphosis were found during follow-up. The fusion time was (5.1±1.6) months in group A and (5.1± 1.7) months in group B, there was no significant difference between two groups (P>0.05). The VAS, ODI score, sagittal Cobb angle, ESR and CRP value of the lesion segment at the last follow-up of the two groups were significantly improved (P<0.05), but there was no significant difference between two groups (P>0.05). CONCLUSION: The two kinds of operation can obtain satisfactory clinical effect. Direct lateral interbody fusion combined with posterior percutaneous screw fixation can reduce intraoperative blood loss and hospital stay, which is conducive to early rehabilitation of patients.

[Treatment strategy and curative effect analysis of os odontoideum complicated with atlantoaxial joint dislocation].

OBJECTIVE: To explore the treatment strategy and clinical efficacy for os odontoideum complicated with atlantoaxial dislocation. METHODS: The clinical data of 17 patients with os odontoideum complicated with atlantoaxial dislocation surgically treated from January 2006 to January 2015 were retrospectively analyzed, including 7 males and 10 females, aged 17 to 53 (43.1±11.3) years old;course of disease was 3 to 27(10.2±6.9) months. All patients received cranial traction before operation, 12 of 14 patients with reducible dislocation were treated by posterior atlantoaxial fixation and fusion, and 2 patients with atlantooccipital deformity were treated by posterior occipitocervical fixation and fusion;3 patients with irreducible alantoaxial dislocation were treated by transoral approach decompression combined with posterior atlantoaxial fixation and fusion. The operation time, intraoperative blood loss and perioperative complications were recorded. Visual analogue scale (VAS) and Japanese Orthopaedic Association (JOA) score were used to evaluate the change of neck pain and neurological function. Atlantoaxial joint fusion rate was evaluated by CT scan. RESULTS: The operation time of posterior fixation and fusion ranged from 86 to 170 (92.2±27.5) min, and the intraoperative blood loss was 200-350 (250.7±65.2) ml. No vertebral artery injury and spinal cord injury were recorded. Among the patients underwent atlantoaxial fixation and fusion, 1 patient with reducible dislocation fixed by C2 laminar screw lost reduction after primary operation, and received anterior release again and finally occipitocervical fusion. All patients were followed up for 15 to 58 (32.0±12.2) months. VAS score was decreased from preoperative 4.2±0.9 to 1.3±0.7 at final follow up and the JOA score was improved from preoperative 11.2±1.2 to 16.9±0.8 at final follow-up. CT scan confirmed that the atlantoaxial or occipitocervical fusion wasgood, and the fusion time was 5 to 9 (6.7±0.6) months. CONCLUSION: Surgical treatment of os odontoideum complicated with atlantoaxial dislocation can achieve satisfactory results, improve the patient's neurological function and improve the quality of life, however the surgical options needs to be individualized.

[Effect of posterior osteotomy on the sagittal parameters of the spinopelvis in patients with lumbar degenerative kyphosis].

OBJECTIVE: To investigate the influence of posterior osteotomy on spinopelvic parameters in lumbar degenerative kyphosis (LDK) patients. METHODS: The clinical data of 21 patients with lumbar degenerative kyphosis who underwent osteotomy from January 2012 to December 2015 were retrospectively analyzed. There were 5 males and 16 females, aged from 55 to 76 years with an average of (66.24±5.13) years. All patients had taken preoperative and postoperative full length spinal X-ray, analyzing the spinopelvic parameters as thoracic kyphosis (TK), lumbar lordosis (LL), sagittal vertical axis (SVA), pelvic incidence (PI), pelvic tilt (PT) and sacral slope (SS). RESULTS: All operations were successful, the average operative time was 190 min (160 to 220 min) and intraoperative blood loss was 1 000 ml (800 to 1900 ml). Parameters of the patients between preoperative and period 1-year follow-up were as follows : preoperative TK increased from (31.67±21.13) ° to (34.67±11.60) °, LL corrected from (4.76±3.17) ° to (37.41±6.28) °, PT reduced from (33.94±5.01) ° to (20.12±5.36) °, and SS improved from (18.47±2.60) ° to (31.71±4.30) °, SVA restored from (13.24±3.60) cm to (2.82±1.33) cm. There were significant differences of spinopelvic parameters between preoperation and postoperation (P<0.05). CONCLUSION: Posterior osteotomy can effectively reconstruct the sagittal balance of spinopelvis in patients with lumbar degenerative kyphosis. The recovery of lumbar lordosis and sacral slope is closely related to the reconstruction of sagittal balance.

[Comparison of the effects of injured vertebra pedicle fixation combined with vertebroplasty and vertebra pedicle screw fixation combined with vertebroplasty in the treatment of osteoporotic thoracolumbar burst fractures].

OBJECTIVE: To assess the curative effects of injured vertebra pedicle fixation combined with vertebroplasty and short-segment pedicle screw fixation combined with vertebroplasty in treatment of osteoporotic thoracolumbar burst fractures. METHODS: Seventy patients with osteoporotic thoracolumbar burst fractures who met the inclusion criteria were collected in the study from January 2015 to December 2017. Among them, 35 patients were treated with injured vertebra pedicle fixation combined with vertebroplasty (group A), including 20 males and 15 females, aged from 55 to 74 years with an average of (64.03± 7.82) years. Twenty-six cases were type A3 and 9 cases were type A4 according to the AO typing;another 35 patients were treated with short segment pedicle screw fixation combined with vertebroplasty (group B), including 18 males and 17 females, aged from 54 to 72 years with an average of (62.78±6.40) years. Twenty-eight cases were type A3 and 7 cases were type A4 according to AO typing. Operation length, intraoperative bleeding volume, complication, imaging parameters and clinical effects were compared between the two groups. RESULTS: All the patients were followed up for at least 12 months. There were no significant differences in gender, age, injury site, preoperative VAS, Cobb angle, and injured vertebral height before surgery. There were no significant differences in operation length, intraoperative bleeding volume between two groups. In terms of VAS scores before surgery, 1 week after surgery, and at the final follow up, group A was 5.5 ±2.5, 1.8 ±0.8, 0.9 ±0.4, group B was 5.4 ± 2.3, 1.7±0.6, 1.2±1.8, respectively;injured vertebral height was (40.4±8.8)%, (92.0±4.9)%, (87.1±3.8)% in group A, and (41.2±6.6)%, (93.2±4.6)%, (80.0±4.3)% in group B;Cobb angle was (18.4±6.9) °, (2.8±2.2) °, (4.2±2.6) ° in group A, and (16.8±7.2) °, (2.7±2.5) °, (6.0±2.4) ° in group B. There were significant differences in the 3 parameters above before the operation and at the final follow up in all groups (P<0.05). There were significant differences in the Cobb angle and injured vertebral height between 1 week after operation and at the final follow up (P<0.05). At the final follow up, injured vertebral height in group A was obviously better than that in group B (P<0.05). Internal fixation failure occurred in 2 cases from the group A, and occurred in 4 cases from the group B. There were no neurological complications in both groups. CONCLUSION: For osteoporotic thoracolumbar vertebral burst fractures, injured vertebra pedicle fixation combined with vertebroplasty and vertebra pedicle screw fixation combined with vertebroplasty can achieve good clinical effects. However, injured vertebra pedicle fixation combined with vertebroplasty is better at maintaining postoperative vertebral height and sagittal arrangement, and reducing internal fixation related complications. The treatment strategy is worthy of application and promotion.

[Efficacy of bilateral sagittal cross percutaneous kyphoplasty for preventing recurrent fracture of the cemented vertebrae].

OBJECTIVE: To explore the efficacy of bilateral sagittal cross percutaneous kyphoplasty(PKP) for preventing recurrent fracture of the cemented vertebrae. METHODS: From January 2017 to June 2017, 85 patients with single-segment osteoporotic vertebral compression fractures(OVCFs) were treated by bilateral sagittal cross PKP(cross group). There were 35 males and 50 females with an average age of (70.1±8.3) years old in cross group. Another 85 patients with single-segment OVCFs were treated by traditional PKP (traditional group). There were 37 males and 48 females with an average age of (73.3±9.5) years old in traditional group. The cement distribution condition, recurrent fracture of the cemented vertebrae, the anterior vertebral body height and sagittal Cobb angle, visual analogue scale(VAS) were observed in two groups. RESULTS: All patients underwent operation successfully. The follow-up time were (11.8±4.5) months in cross group and (12.1±3.7) months in traditional group. In cross group, all patients' bone cement touched the upper and lower endplates of the vertebral body while 67 cases (78.8%) in traditional group did with significant difference between two groups (P<0.05). No patient in cross group suffered recurrent fracture of the cemented vertebrae while 10 cases (11.8%) in traditional group did with significant difference between two groups(P<0.05). The anterior vertebral body height, sagittal Cobb angle and VAS in both groups were obvious improved at 2 days after operation (P<0.05) and there were no significant difference between two groups at 2 days after operation and the final follow-up(P>0.05). CONCLUSIONS: Bilateral sagittal cross PKP was a simple, safe and effective technique which can make bone cement distribute in the fractured vertebral body and contact the upper and lower endplates of the vertebral body, thus preventing the recurrent fracture of the cemented vertebrae.

[One stage temporary atlantoaxial segmental fixation and reduction for Grauer type IIB dens fractures in teenagers].

OBJECTIVE: To assess the clinical results of one stage temporary atlantoaxial segmental fixation and reduction for Grauer type IIB dens fractures in teenagers. METHODS: From February 2009 to April 2015, 19 teenagers with Grauer type IIB dens fractures not amenable to anteiror screw fixation were enrolled and treated using one stage temporary atlantoaxial segmental fixation and reduction without fusion. There were 14 males and 5 females, aged from 14 to 32 years with an average of (24.6±5.0 ) years. The internal fixation was removed after bone healing confirmed by CT scan. At the last follow-up (at least 1 year after internal fixation removal), dynamic CT was used to assess the atlantoaxial rotation activity. Visual analogue scale (VAS) was recorded before the first operation, before the second operation (removal of internal fixation) and at the last follow-up. Neck Disability Index(NDI) was used to evaluate the efficacy before the second operation (removal of internal fixation) and the last follow-up. RESULTS: After operation, 2 patients developed the symptoms of occipital nerve stimulation such as numbness and pain in the occipitocervical region, and were treated with drugs such as dehydration and neurotrophic drugs, and the symptoms were relieved after 1 to 2 months. All the internal fixations were removed and all the patients were followed up more than 1 year, with time ranging from 18 to 25 months and an average of (21.47±2.41) months. The time of bone fusion after operation was 6 to 10 months with the mean of(8.21±1.27) months. Secondary surgical removal of internal fixation were performed immediately after fracture healing without internal fixation failure. The symptoms of neck pain improved significantly after operation, VAS score decreased from 6.74±0.65 before operation to 0.42±0.51 at the last follow-up after the second operation (removal of internal fixation), with statistically significant differences(P<0.01). The NDI value decreased from (10.58±2.04)% before the second operation (removal of internal fixation) to (3.79±2.23)% at the last follow-up after the second operation (removal of internal fixation), with statistically significant difference(P<0.01). At the last follow-up after the second operation (removal of internal fixation), dynamic CT showed that the unilateral rotation of the atlantoaxial spine reached (15.73±5.57)° to the left, (15.55±5.78)° to the right, and the overall rotation of the atlantoaxial spine was (31.28±10.71)°. CONCLUSIONS: One stage temporary atlantoaxial segmental fixation and reduction for the treatment of Grauer type IIB dens fractures not amenable to anteiror screw fixation in teenagers can avoid the loss of atlantoaxial rotation function caused by atlantoaxial fusion, and to some extent retain the rotation activity of atlanto-axial joint.

Biomechanical comparison of cervical transfacet pedicle screws versus pedicle screws.

BACKGROUND: Transfacet pedicle screws provide another alternative for standard pedicle screw placement for plate fixation in the lumbar spine. However, few studies looking at transfacet pedicle screw fixation in the cervical spine are available. Therefore, cervical transfacet pedicle screw fixation and standard pedicle screw fixation techniques were biomechanically compared in this study. METHODS: Ten fresh human cadaveric cervical spines were harvested. On one side, transfacet pedicle screws were placed at the C3-4, C5-6, and C7-T1 levels. On the other side, pedicle screws were placed at the C3, C5, and C7 levels. The screw insertion technique at each level was randomized for right or left. The starting point for the transfacet pedicle screw insertion was located at the midpoint of the inferolateral quadrant of the lateral mass and the direction of the screw was about 50 degrees caudally in the sagittal plane and about 45 degrees toward the midline in the axial plane. Screws were placed from the inferior articular process, across the facet complex and the pedicle into the body of the caudal vertebra. The entry point for the pedicle screw was located at the midpoint of the superolateral quadrant of the lateral mass, and the direction of the screw was about 45 degrees toward the midline in the axial plane and toward the upper third of the vertebral body in the sagittal plane. After screw placement we performed axial pullout testing. RESULTS: All the cervical transfacet pedicle screws and the pedicle screws were inserted successfully. The mean pullout strength for the transfacet pedicle screws was 694 N, while for the pedicle screws 670 N (P=0.013). In all but six instances (10%), the pedicle screw pullout values exceeded the values for the transfacet pedicle screws; this occurred three times at the C3/C4 level, twice at the C5/C6 level and once at the C7/T1 level. The greatest pullout strength difference at a single level was observed at the C5/C6 level, with a mean difference of 38 N (t=-1.557, P=0.154). The C7/T1 level had a mean difference of 26 N and the C3/C4 level had a mean difference of 14 N. CONCLUSIONS: Cervical transfacet pedicle screws exhibited higher pullout strength than pedicle screws. Posterior transfacet pedicle screw fixation in the cervical spine may afford an alternative to standard screw placement for plate fixation and cervical stabilization.

[Treatment of senile spinal tuberculosis with posterior percutaneous pedicle screw fixation combined with local percutaneous endoscopic debridement].

OBJECTIVE: To explore the short-term efficacy of posterior percutaneous screw fixation combined with local percutaneous endoscopic debridement in treating senile spinal tuberculosis. METHODS: The clinical data of 19 senile patients with spinal tuberculosis underwent surgical treatment from January 2015 to September 2016 were retrospectively analyzed. There were 13 males and 6 females, aged from 60 to 73 years old with an average of (66.2±4.0) years. All patients have been diagnosed with spinal tuberculosis prior to hospitalization with abscess, dead bone formation but no sinus, neurological symptoms, open surgical indications. All patients were treated with posterior percutaneous screw fixation combined with local percutaneous endoscopic debridement, and were given appropriate chemotherapy for 3 weeks preoperatively. Pre-and post-operative visual analogue score (VAS), Oswestry Disability Index (ODI), sagittal Cobb angle of lesion segment, erythrocyte sedimentation rate(ESR), C-reactive protein(CRP) were analyzed. RESULTS: All the 19 patients successfully completed the operation and passed through the perioperative period safely. The operation method was unchanged during the operation. The average operation time was (153.2±14.0) min. Except for 1 patients who had delayed incision healing, other patients healed at I stage within 2 weeks after operation. All patients were followed up for 15 to 26 months with an average of (19.6±3.2) months.VAS, ODI, sagittal Cobb angle of lesion segment, ESR, CRP were decreased from preoperative(5.9±1.1) points, (80.9±4.0)%, (30.8±5.5)°, (79.6±14.4) mm/h, (56.9±9.5) mg/L to(1.8±0.9) points, (66.4±5.4)%, (15.9±2.5)°, (20.4±4.6) mg/L, (32.0±8.1) mm/h at final follow-up(P<0.05). CONCLUSIONS: Senile spinal tuberculosis have more complications and poor general body condition. Posterior percutaneous pedicle screw fixation combined with local percutaneous endoscopic debridement in treating the patients can reduce trauma, got satisfactory effect.

[Percutaneous pedicle screw fixation combined with limited-open decompression technique for thoracolumbar fractures with neurologic deficit].

OBJECTIVE: To evaluate the clinical effects of percutaneous pedicle screw fixation combined with limited open decompression technique for the treatment of thoracolumbar fractures with neurologic deficit. METHODS: The clinical data of 76 patients with thoracolumbar fractures with neurologic deficit underwent percutaneous pedicle screw fixation combined with limited open decompression technique from June 2010 to June 2014 were retrospectively analyzed. There were 45 males and 31 femals, aged from 17 to 56 years with an average of 32.5 years old. According to the classification of Denis, 33 cases were type A, 26 cases were type B, 17 cases were type C. According to the criterion of American Spinal Injury Association(ASIA), 13 cases were grade A, 9 cases were grade B, 21 cases were grade C, 33 cases were grade D. The operative time, intraoperative blood loss, postoperative internal fixation lossening and breakage were recorded. The informations of the Cobb angle, the anterior height of injured vertebra, canal stenosis were observed before operation, 3 days after operation, and the final follow-up. The improvement of neurologic function were analyzed at final follow-up. RESULTS: All the patients were followed up from 13 to 47 months with an average of 32.1 months. The mean operative time was 159 min (136 to 218 min) and the intraoperative blood loss was 225 ml(150 to 360 ml). The anterior height of injured vertebra was increased from (52.0±5.9)% before operation to (87.2±1.8)% at 3 days after operation, and (86.1±1.5)% at final follow-up (F=45.27, P=0.000); the Cobb angle was decreased from (29.7±8.2)° before operation to (5.7±2.9)° at 3 days after operation, and (5.9±3.6)° at final follow-up (F=34.62, P=0.000); the canal stenosis was decreased from (37.5±7.2)% before operation to (12.3±3.3)% at 3 days after operation, and (11.9±3.1)% at final follow-up(F=37.02, P=0.000); there was no significant differences between postoperative 3 days and the final follow-up about the above parametres(P>0.05). According to ASIA criterion, the spinal cord function was classified as grade A in 13 cases, grade B in 0 cases, grade C in 10 cases, grade D in 21 cases and grade E in 32 cases at final follow-up. Internal fixation lossening and breakage occurred in 2 cases. CONCLUSIONS: Percutaneous pedicle screw fixation combined with limited open decompression technique can obtain satisfactory clinical effect for patients with thoracolumbar fractures with neurologic deficit, and have a good recovery of nerve function can be observed.

[Case-control study of pedicle screw fixation combined with vertebroplasty and injured vertebra pedicle fixation in treatment of osteoporotic thoracolumbar burst fractures].

OBJECTIVE: To compare the curative effect of short-segment pedicle screw fixation combined with vertebroplasty and injured vertebra pedicle fixation in treating osteoporotic thoracolumbar burst fractures. METHODS: A retrospective study was performed for 52 patients with thoracolumbar burst fractures from August 2010 to August 2015. Among them, 27 patients(group A) were treated with short-segment pedicle screw fixation combined with vertebroplasty, including 17 males and 10 females, aged from 54 to 68 years old with an average of(61.01±5.41) years, 16 cases were type A3 and 11 cases were type A4 according the new AO typing. Other 25 patients (group B) were treated with short-segment pedicle screw fixation combined with injured vertebra pedicle fixation, including 12 males and 13 females, aged from 55 to 66 years old with an average of (59.28±6.12) years, 18 cases were type A3 and 7 cases were type A4 according the new AO typing. Operation time, intraoperative bleeding volume, complication, image data and clinical effect were compared between two groups. RESULTS: All the patients were followed up for 12 to 15 months with an average of (12.4±2.1)months. There was no significant difference in general data(including gender, age, injured site, preoperative VAS score, Cobb angle, injured vertebral anterior border height) between two groups. There was no significant differences in operation time, intraoperative bleeding volume between two groups. Preoperative, one week after operation and final follow-up, VAS scores were 5.2±0.5, 1.2±0.2, 0.8±0.1 respectively in group A and 5.0±0.6, 2.5±0.4, 1.3±0.2 in group B; injured vertebral anterior border height were (49.4±6.8)%, ( 94.5±1.2)%, ( 94.1±3.7)% respectively in group A and (48.2±7.0)%, ( 94.3±4.1)%, ( 90.0±2.3)% in group B;Cobb angles were (20.4±5.2) °, (2.5±1.8) °, (4.4±1.7)° respectively in group A and (19.8±6.8)°, (2.4±1.7)°, (7.0±1.2)° in group B. At final follow-up, VAS, Cobb angle, injured vertebral anterior border height in two groups were obviously improved(P<0.05). Postoperative at 1 week and final follow-up, VAS score of group A was lower than that of group B(P<0.05);and there was no significant difference in Cobb angle between two groups(P>0.05); there was significant difference in injured vertebral anterior border height between two groups(P<0.05). The complication of internal fixation failure had 1 case in group A and 4 cases in group B. CONCLUSIONS: For the treatment of single osteoporotic thoracolumbar burst fractures, short-segment pedicle screw fixation combined with vertebroplasty is better than combined with injured vertebra pedicle fixation in clinical effect, it can relieve pain, maintain injured vertebral height and sagittal alinement, reduce the complications associated with internal fixation, and be worth spread in clinic.

[A static mechanical comparison between two transarticular internal fixation techniques in the lower cervical spine].

OBJECTIVE: To compare static mechanical difference between two transarticular internal fixation techniques in the lower cervical spine. METHODS: Ten fresh human cadaveric cervical spines were harvested. On one side, transarticular pedicle screws were placed at the C3-4, C5-6, and C7-T1 levels, and transarticular screws were placed on the other side. The screw insertion technique at each level was randomized for right or left. The starting point for transarticular pedicle screw insertion was located at the midpoint of the inferolateral quadrant of the lateral mass and the direction of the screw was about 50 degrees caudally in the sagittal plane and about 45 degrees medially in the axial plane, and the starting point for transarticular screw insertion was 1 mm medial to the midpoint of the lateral mass, aiming in a 15 - 20 degrees caudally and 35 - 40 degrees lateral position. After screw placement, each set of vertebral bodies were mounted in a custom jig for axial pullout testing using a servohydraulic testing machine. The load-displacement curves were obtained for each screw pullout. RESULTS: The mean pullout strength for the transarticular pedicle screws was 668 N. This compares with 414 N for the transarticular screws (P < 0.05), but there was not significant difference statistically between different cervical levels (P > 0.05). CONCLUSION: The static mechanical strength of transarticular pedicle screws is superior to the transarticular screws, and the transarticular pedicle screw fixation has the biomechanical feasibility of clinical application.

[Characterization of the ectC gene and its expression product in Halomonas sp. Nj223 from Antarctica deep-sea sediment].

A moderately halophilic bacterium Halomonas sp. NJ223 was isolated from Antarctica deep-sea sediment. This bacterium accumulates ectoine as the main compatible solute in response to severe osmotic stress. Ecoine synthase catalyzes circulation of gamma-N-acetyl-alpha, gamma-diaminobutyric acid (ADABA) to ectoine in the last step of the three enzymatic steps. The gene of ectoine synthase from this strain was amplified by PCR and the DNA sequence of a 393-bp segment was sequenced. The amino acid sequences of this enzyme present high homology to the known sequence. The significance of this gene was proved by the expression in Escherichia coli. Thus, the amplified fragment was cloned into the expression vector pET-his. The insert position, the size and the reading frame were identified by PCR, restriction digestion and the sequence analysis of the recombinant plasmids. SDS-PAGE shows that the relative molecular mass of the expression product was 15 kDa as predicted, which indicated that the recombinant plasmids could express the gene of ectoine synthase. The biosynthetic pathway of ectoine was partially elucidated by renaturation and enzyme activity detection of purified ectoine synthase in vitro. Determination of effect of pH and temperature on enzyme activity shows that the optimal reaction condition of pH was 8.0 and temperature was 25 degrees C.