Correlative factors of low back pain after single-level oblique lateral interbody fusion / 中华骨科杂志

Objective:The study retrospectively identified the correlative factors of low back pain after single-level oblique lateral interbody fusion (OLIF).Methods:Records of 93 patients (55 males and 38 females) who underwent OLIF (oblique lateral interbody fusion) surgery for lumbar degenerative diseases from May 2016 to September 2019 were analyzed retrospectively and patients' age was 55.73±9.48 years (range 32-78 years). There were 18 patients underwent L 3, 4 segment (19.35%), 73 patients underwent L 4, 5 segment (78.50%), and 2 patients underwent L 5S 1 segment (2.15%). There were 43 patients underwent OLIF stand alone and 50 patients underwent OLIF combined with lateral or posterior internal fixation. The follow-up time was 22.86±5.90 months (range 12-32 months). According to whether the visual analog scale (VAS)≥3 at the last follow-up visit, the patients were divided into low back pain group and no low back pain group. The demographic characteristics (age, gender, body mass index and comorbidities), basic surgical data (surgical segments, surgical methods, surgical time, intraoperative bleeding, endplate injury or not during operation), imaging data (lumbar lordosis, segmental lordosis, intervertebral height and cage subside) and lumbar function were recorded. The potential related factors were analyzed by univariate analysis, and the factors with P<0.05 were selected in the multivariate logistic regression model. Then the risk factors of low back pain after OLIF were determined by multivariate logistic regression analysis. Results:Nineteen patients with VAS score equal or greater than 3 were included in low back pain group, and the remaining 74 patients were included in no low back pain group. There was no significant difference in baseline data such as age, gender, BMI, follow-up time and comorbidities between two groups. There was no significant difference in VAS score between the two groups before operation ( t=0.818, P=0.414), but there was significant difference in VAS score at last follow-up visit ( t=6.958, P<0.001). The incidence rate of osteoporosis in low back pain group (63.16%) was significantly higher than that in no low back pain group (25.68%) ( t=9.558, P=0.002). There was no significant difference in vertebral height between the two groups ( t=1.008, P=0.316), however, the vertebral height was higher in no low back pain group ( t=2.537, P=0.316) at the last follow-up. The incidence of cage subsidencewas 8.11% in no low back pain group and 36.84% in low back pain group and there was significant difference between the two groups ( t=10.381, P=0.001). Multivariate logistic regression analysis showed that osteoporosis ( P=0.009), intraoperative bone endplate injury ( P=0.031), decreased intervertebral space height ( P=0.029) and cage subsidence ( P=0.016) were associated with low back pain after single-level OLIF. Conclusion:Low back pain is one of the common complications after OLIF. Osteoporosis, intraoperative bony endplate injury, decreased intervertebral space height and cage subsidence were closely related to postoperative low back pain. In order to reduce the incidence of postoperative low back pain and improve the clinical outcomes, attention should be paid to the protection of the bony endplate, rational use of internal fixation and active anti-osteoporosis treatment after operation.

Efficacy of posterior pedicle screw reduction and internal fixation of atlantoaxial fractures: comparison between O-arm navigation assisted and free-hand techniques / 中华创伤杂志

Objective:To investigate the effect of O-arm navigation assisted posterior pedicle screw reduction and internal fixation of atlantoaxial fractures.Methods:A retrospective case-control study was conducted to analyze 37 patients with atlantoaxial fractures admitted to Third Hospital of Hebei Medical University from January 2016 to June 2018, including 22 males and 15 females, aged from 29 to 68 years [(50.9±9.8)years]. The posterior pedicle screw reduction and internal fixation was performed under O-arm navigation system (navigation group, n=24), and using free-hand technique (free-hand group, n=13). The operation time and blood loss were compared between the two groups. The Japanese Orthopaedic Association (JOA) score and neck disability index (NDI) were used to evaluate the clinical efficacy before operation, 7 days operation and at the last follow-up. The complications were detected. A total of 86 screws were placed in navigation group (Neo grade 0: 83 screws, grade 1: 2 screws, grade 2: 1 screw ), and 44 screws were inserted in free-hand group (Neo grade 0: 36 screws, grade 1: 5 screws, grade 2: 2 screws, grade 3: 1 screw)( P<0.05). Classification of screw positions proposed by Neo et al was used to evaluate the position relationship between the screw and the bone cortex and the incidence of screw penetration. Results:All patients were followed up 24-38 months [(27.7±4.0)months]. The operation time in navigation group was (189.8±35.4)minutes, significantly shorter than (221.5±48.6)minutes in free-hand group ( P<0.05). The bleeding volume in navigation group was 300.0 (250.0, 537.5)ml , significantly less than 500.0 (425.0, 625.0)ml in free-hand group ( P<0.05). Both groups showed significantly enhanced JOA and decreased NDI after operation and at last follow-up, compared with those before operation ( P<0.05). However, there was no significant difference in JOA and NDI between the two groups ( P>0.05). No severe complications such as neurovascular injury occurred during operation. The incidence of cortical penetration was 3% (3/86) in navigation group and 18% (8/44) in free-hand group ( P<0.05). Conclusions:In the process of posterior atlantoaxial pedicle screw placement, the application of O-arm navigation can significantly reduce the operation time and amount of bleeding, and enhance the accuracy of pedicle screw implantation.

Efficacy comparison of two posterior osteotomy methods for old thoracolumbar compressive fracture accompanied with kyphotic deformity / 中华创伤杂志

Objective To compare the clinical efficacy of pedicle subtraction osteotomy(PSO)and posterior unilateral vertebral column resection(PUVCR)for old thoracolumbar compressive fracture accompanied with kyphotic deformity.Methods A retrospective case control study was conducted to analyze the clinical data of 51 patients with old thoracolumbar fracture accompanied with kyphotic deformity admitted to the Third Hospital of Hebei Medical University from January 2010 to January 2016.There were 29 males and 22 females,aged 46-69 years,with an average age of 54.9 years.In terms of the injured segments,there were 11 patients with T11,10 with T12,17 with L1,and 13 with L2.A total of 22 patients were treated with traditional PSO(PSO group),and 29 patients PUVCR(PUVCR group).The operation time,intraoperative blood loss,hospital stay,Cobb angle improvement 2 weeks after operation and postoperative 1 year,visual analogue scale(VAS) 1 year after operation and Japanese Orthopedic Association(JOA)scores were compared between the two groups.Intraoperative and postoperative complications were recorded.Results All patients were followed up for 3-18 months,with an average of 13.5 months.There were no significant differences between PSO group and PUVCR group in hospital stay[(13.8±1.1)days vs.(14.1±1.2)days],thoracolumbar Cobb angle 2 weeks after operation[(8.3±1.5)°vs.(9.1±2.0).]and JOA scores[(26.2±1.2)points vs(25.5±1.5)points](P＞0.05).Significant differences were found between PUVCR group and PSO group in operation time[(184.9±22.9)minutes vs.(219.9±17.1)minutes],intraoperative blood loss[(911.5±70.2)ml vs.(1136.1±92.0)ml],Cobb angle 1 year after operation[(10.0±1.6)°vs.(12.7±1.9)°],and VAS 1 year after operation[(2.3±0.5)points vs.(2.9±0_ 7)points](P＜0.05).No serious complications occurred during operation and follow-up.Conclusions For old thoracolumbar compressive fracture accompanied with kyphotic deformity,PSO and PUVCR can both effectively improve kyphosis and relieve dysfunction.But PUVCR has the advantages of shorter operation time,less intraoperative blood loss,better-improved kyphosis,and lower incidence of spinal nerve injury.

Research progress on superparamagnetic iron oxide nanoparticles for targeted drug delivery / 国际生物医学工程杂志

Superparamagnetic iron oxide (SPIO) is a novel biomedical nanomaterial with surface effect,small size effect and macroscopic quantum tunneling effect.It has good biocompatibility and superparamagnetism which makes it widely used in targeted therapies.Compared to other nanodrug carriers,superparamagnetic iron oxide nanoparticles (SPIONs) have great potentials in nanodrug filed due to their properties such as intrinsic magnetic,good safety and the availability of surface modifications,etc.These properties provide the basis for their diverse applications in biomedical field.However,researchers are still concerned about the unpredictable toxicity and the changes in cell signal transduction and gene expression of SPIONs.In this paper,the research progress of SPIONs for drug targeting delivery was summarized.

Research progress on superparamagnetic iron oxide nanoparticles for targeted drug delivery / 国际生物医学工程杂志

Superparamagnetic iron oxide (SPIO) is a novel biomedical nanomaterial with surface effect,small size effect and macroscopic quantum tunneling effect.It has good biocompatibility and superparamagnetism which makes it widely used in targeted therapies.Compared to other nanodrug carriers,superparamagnetic iron oxide nanoparticles (SPIONs) have great potentials in nanodrug filed due to their properties such as intrinsic magnetic,good safety and the availability of surface modifications,etc.These properties provide the basis for their diverse applications in biomedical field.However,researchers are still concerned about the unpredictable toxicity and the changes in cell signal transduction and gene expression of SPIONs.In this paper,the research progress of SPIONs for drug targeting delivery was summarized.