Objective To discuss diagnosis and anterior surgical treatment of hyperextensian cervical spine injury combined with intervertebral disk injury. Methods A retrospective study was done on clinical data of 27 patients who suffered from hyperextension cervical spine injury combined with intervertebral disk injury to analyze their age distribution, clinical symptomes, X-ray and MRi manifesta-tions and perioperative intervertebral disk injury. All patients were treated with discectomy, strut bone grafting within vertebral bodies and internal fixation with titanium plate. The clinical outcomes were evalu-ated by using Frankel scale and ASIA motor score (AMS). Results Both MRI and X-ray detected following abnormal pathological changes in all patients: rupture of anterior longitudinal ligament, horizon-tal tear of disk, intervertebral disk hernia, compression and edema of spinal cord. The follow-up lasted for 9-32 months (average 17.5 months), which showed that all patients got improvement for 1-3 scales except that one patient with Frankel A had no improvement in neurological function. Compared with AMS on admission, both AMS at two months after surgery and at final follow-up was increased significantly, with recovery rate of AMS for 44.9% and 68.1%, respectively. There found no hardware related compli-cations such as implant loosening, defluxion or breakage. Bone fusion was found in all fixation segments. Conclusions MRI and X-ray are important examination means for hyperextension cervical spine injury combined with intervertebral disk injury. On a specified diagnosis, anterior surgical treatment should be done early and can get satisfactory recovery of spinal cord function.

ObjectiveTo evaluate the clinical effects of guiding apparatus assisted individual posterior cervical pedicle screw fixation technique.MethodsThe study enrolled 24 patients treated with posterior cervical decompressive single open-door laminoplasty and transpedicular screw-rod fixation from January 2008 to December 2010.The point of screw penetration and screw path direction were confirmed by measuring the transverse nail angle (TNA) and sagittal nail angle (SNA) of nail channel on the pre-operative CT plain scan of cervical pedicle and sagittal two-dimensional imaging of transpedicular axis.According to the results of CT measurement,individual cervical pedicle screw was implanted with the assistance of self-made guiding apparatus and then fixed after decompression.Transverse screw angle ( TSA ) and sagittal screw angle ( SSA ) were determined on the CT scan of cervical pedicle and sagittal two-dimensional imaging of transpedicular axis one week postoperatively in order to analyze the accuracy of placement of pedicle screws.Periodical anteroposterior and lateral X-ray radiographs of cervical vertebra were taken postoperatively to detect the stabilization of internal fixation.ResultsA total of 223 pedicle screws were inserted successfully into the C3 ～ C7,of which 220 crews were inserted accurately but three had slight inclination according to the postoperative CT,with placement accuracy of 98.7％.The comparison between inclination angle of inserted screws and that of preoperative transpedicular axis showed insignificant statistical difference ( P ＞ 0.05 ).All the patients were followed up for 6-34 months ( mean,18.5 months),which showed no neurovascular complications related to screws perforation out of pedicle cortex or no screw loosening,prolapse or breakage.ConclusionPosterior cervical pedicle screw insertionperformed according to the individual CT measurement is easy and safe and has a high accuracy rate under the assistance of self-made guiding apparatus.

Objective To evaluate the clinical efficacy of a self-designed novel n-shaped aiming device in aiding the percutaneous cannulated screwing for treatment of odontoid fractures of Anderson-D' Alonzo type Ⅱ and shallow type Ⅲ.Methods A retrospective analysis was conducted of the 17 patients who had been treated at our department for odontoid fracture of Anderson-D' Alonzo type Ⅱ and shallow type Ⅲ between January 2009 and December 2013.They were 13 males and 4 females,with an average age of 37.5 years (from 16 to 61 years).All received surgical treatment after skull traction or jaw pillow traction preoperatively for reduction.Intraoperatively,percutaneous cannulated screwing via the anterior cervical approach was performed with the help of a self-designed novel n-shaped aiming device to fix the odontoid.Postoperatively,X-ray and CT scan were used to check the screw locations and evaluate the fracture healing.Results The 17 cases were followed up for 6 to 15 months (average,10.5 months).No intraoperative injury to the esophagus,artery,spinal cord or nerve root happened.The operating time ranged from 60 to 125 min.The bleeding was from 10 to 40 mL.Intraoperative observation revealed fine locations of the screws.Bony union was achieved in 16 cases 3 months postoperatively while separation and hardening of the fracture ends was found in one ease.Conclusion Our self-designed novel n-shaped aiming device can facilitate the percutaneous cannulated screwing for treatment of odontoid fractures of Anderson-D'Alonzo type Ⅱ and shallow type Ⅲ,given that it has advantages of simple manipulation,accurate insertion,minimal invasion,quick recovery and reliable efficacy.

Objective To investigate the clinical effect of percutaneous kyphoplasty (PKP) in treatment of osteoporotic vertebral fractures and collapse with intravertebral vacuum sign.Methods A retrospective study was conducted on the clinical and radiological data of 31 patients with osteoporotic vertebral fractures and collapse with intravertebral vacuum sign treated by PKP from June 2009 to June 2011.Vertebrae body variation,visual analog scale (VAS) and Oswestry disability index (ODI) before operation,during follow-up at postoperative one week and at postoperative 3-6 months were used as outcome measurements.Results All the patients went through operations successfully and presented significant mitigation of low back pain in 24 hours after operation.The vertebrae body height at postoperative one week [(17.2 ±4.2) mm] and at postoperative 3-6 months [(16.8 ±5.1)mm] were statistically different from that before operation [(11.4 ± 1.7) mm,P ＜0.01],while there was no statistical difference between the two follow-ups (P ＞ 0.05).VAS and ODI at postoperative one week [(2.8 ± 1.7) points and (31.6 ± 8.4) points] were statistically different from those before operation [(8.6 ± 1.3) points and (78.3 ±8.5) points,P＜0.01].VAS and ODI at postoperative 3-6 months [(2.3 ±0.8) points and (23.7 ± 2.3) points] presented statistical differences from those before operation (P ＜ 0.01),but no statistical differences from those at postoperative one week (P ＞ 0.05).Conclusion PKP obtains satisfactory clinical outcomes,for it relieves low back pain and restores vertebral body height.

Objective:To investigate the feasibility and clinical efficacy of posterior vertebral column resection (PVCR) combined with polymethylmethacrylate-augmented pedicle screw instrumentation and shortening of spinal column for stage Ⅲ Kümmell's disease with very severe collapse of fractured vertebra.Methods:From January 2017 to September 2021, 9 patients with stage Ⅲ Kümmell's disease with very severe collapse of fractured vertebra underwent PVCR combined with polymethylmethacrylate-augmented pedicle screw instrumentation and shortening of spinal column. Their medical records were retrospectively analyzed. There were 1 male and 8 females, aged (66.9±5.8) years. The injured vertebra was located at T 11 in 2 patients, at T 12 in 4, at L 1 in 2 and at L 2 in 1. X-ray, CT and MRI were performed before operation. The posterior intervertebral heights of adjacent vertebral bodies of the fractured vertebra in the median sagittal position were measured on CT or MRI to evaluate the shortening of the spinal column before PVCR. Recorded were intraoperative bleeding volume, operation time, complications, bone graft fusion, and American Spinal Injury Association (ASIA) grading at preoperation and the last follow-up. The visual analogue scale (VAS) pain scores, Oswestry disability index (ODI) scores, and kyphotic cobb angles at preoperation, 1 week and 3 months postoperation, and the last follow-up were compared to evaluate the clinical efficacy of PVCR. Results:All patients underwent surgery successfully, with tight closure of adjacent vertebrae after resection of the injured vertebra and bone grafting. Operation time was (240.6±23.2) min and intraoperative bleeding (505.6±95.0) mL. The 9 patients were followed up for (17.3±5.6) months. No worsening symptoms of nerve injury, cerebrospinal fluid leakage, or other serious complications were found after operation, nor such complications as loosening or breakage of internal fixation or adjacent vertebral fractures. Bone fusion was achieved at the bone graft sites in all patients by the last follow-up. The VAS and ODI scores and cobb angles at 1 week and 3 months postoperation and at the last follow-up were significantly decreased compared with preoperation ( P<0.05). There were no significant differences in VAS scores or cobb angles among postoperative 1 week and 3 months and the last follow-up ( P>0.05), but pairwise comparisons between different time points after operation showed significant differences in ODI, with postoperative 1 week > postoperative 3 months > the last follow-up ( P<0.05). The ASIA grading at the last follow-up was improved from preoperative grade C to grade D in 2 cases, from preoperative grade C to grade E in 1 case and from preoperative grade D to grade E in 5 cases. Conclusion:PVCR combined with polymethylmethacrylate-augmented pedicle screw instrumentation and shortening of spinal column is a feasible and effective surgical treatment for stage Ⅲ Kümmell's disease with very severe collapse of fractured vertebra, leading to good clinical efficacy.

Objective To assess the efficacy of internal fixation assisted with Halo-vest in the treatment of Anderson-D'Alonzo type Ⅱ and superficial type Ⅲ odontoid fractures.Methods A retrospective case series study was made on 15 patients clinically diagnosed as Anderson-D'Alonzo type Ⅱ and type Ⅲ odontoid fractures with a fracture gap over 2 mm,displacement over 5 mm and broken end angel over 11° from January 2007 to January 2015.There were nine males and six females,aged 27-61 years [(44.5 ± 10.9)years].The patients were treated in "three phases" with the assistance of Halo-vest external fixation system and a novel guide pin aiming device.The three phases were as follows:phase Ⅰ:cervical traction reduction and halo-vest external fixation;phase Ⅱ:Halo-vest assisted internal fixation using the novel aiming device;phase Ⅲ:the Halo-vest fixation removal and cervical collar fixation.Operation duration,intraoperative bleeding,and postoperative visual analogue scale (VAS) pain score one month after the operation were recorded.The cervical lateral and open mouth X-ray or atlantoaxial CT scan with sagittal and coronal two-dimensional reconstruction were regularly reviewed,and the location of screws,reduction and fracture healing were evaluated.Results Operation duration ranged from 54 to 96 minutes [(71.3-± 11.9) min].The intraoperative blood loss was 5-60 ml [(32.6 ± 16.8) ml].There was no spinal cord or nerve root injury,cerebrospinal fluid leakage,wound infection or other complications.All patients were followed up for 12-36 months (mean,28 months).Fourteen patients were seen bony union 6 months after the surgery and one patient was seen a false joint.At the last follow-up,the patient with false joint was seen bone sclerosis,and other patients with sound bone healing.The preoperative VAS and that of one month after the operation was (7.3 ± 0.6) points and (1.6 ± 0.7) points,respectively (P ＜ 0.05).Conclusion For Anderson-D'Alonzo type Ⅱ and type Ⅲ odontoid fractures,which have a fracture gap greater than 2 mm,displacement more than 5 mm,broken end angle above 11 degrees,the three-phase Halo-vest assisted internal fixation can provide good stability before operation and promote bone healing and pain relief after operation.

Staphylococcal nuclease A (SNA) may be used to produce bacterial ghosts for further inactivation of host bacteria and elimination of residual genetic materials. It is still controversial if SNA without signal peptide can be secreted to extracellular matrix and if fusion with other peptide is required for its function in the cytoplasm of host bacteria. To clarify this dispute, a series of temperature-inducible plasmids carrying SNA alone or SNA fused with partial sequences of λ phage cro gene (cSNA) or Mycobacterium tuberculosis urease gene (uSNA) were constructed and evaluated in Escherichia coli. Results show that the percentages of inactivated E. coli by SNA, cSNA and uSNA after 4 h of induction were 99.9%, 99.8% and 74.2%, respectively. Moreover, SNA and cSNA in the cytoplasm of host bacteria were initially detectable after 30 min of induction, whereas uSNA was after 1 h. In comparison, SNA and cSNA in culture supernatant were initially detectable 1 h later, whereas uSNA was 2 h later. The nuclease activity in the cytoplasm or supernatant was ranked as follows: SNA > cSNA > uSNA, and the activity in the supernatant was significantly lower than that in the cytoplasm. Furthermore, host genomic DNA was degraded by SNA or cSNA after 2 h of induction but not by uSNA even throughout the whole experiment. In conclusion, this study indicates that SNA, cSNA and uSNA expressed in host bacteria all have nuclease activity, the enzymes can be released to culture media, and fusion with exogenous peptide negatively reduces the nuclease activity of SNA.
Bacteriolysis ; Bacteriophage lambda ; DNA ; chemistry ; Escherichia coli ; Genetic Vectors ; Micrococcal Nuclease ; chemistry ; Plasmids ; Protein Sorting Signals