Advances in surgical strategies for ossification of posterior longitudinal ligament involving the C 2 segment / 中国修复重建外科杂志

OBJECTIVE@#To evaluate the application of surgical strategies for the treatment of cervical ossification of the posterior longitudinal ligament (OPLL) involving the C 2 segment.@*METHODS@#The literature about the surgery for cervical OPLL involving C 2 segment was reviewed, and the indications, advantages, and disadvantages of surgery were summarized.@*RESULTS@#For cervical OPLL involving the C 2 segments, laminectomy is suitable for patients with OPLL involving multiple segments, often combined with screw fixation, and has the advantages of adequate decompression and restoration of cervical curvature, with the disadvantages of loss of cervical fixed segmental mobility. Canal-expansive laminoplasty is suitable for patients with positive K-line and has the advantages of simple operation and preservation of cervical segmental mobility, and the disadvantages include progression of ossification, axial symptoms, and fracture of the portal axis. Dome-like laminoplasty is suitable for patients without kyphosis/cervical instability and with negative R-line, and can reduce the occurrence of axial symptoms, with the disadvantage of limited decompression. The Shelter technique is suitable for patients with single/double segments and canal encroachment >50% and allows for direct decompression, but is technically demanding and involves risk of dural tear and nerve injury. Double-dome laminoplasty is suitable for patients without kyphosis/cervical instability. Its advantages are the reduction of damage to the cervical semispinal muscles and attachment points and maintenance of cervical curvature, but there is progress in postoperative ossification.@*CONCLUSION@#OPLL involving the C 2 segment is a complex subtype of cervical OPLL, which is mainly treated through posterior surgery. However, the degree of spinal cord floatation is limited, and with the progress of ossification, the long-term effectiveness is poor. More research is needed to address the etiology of OPLL and to establish a systematic treatment strategy for cervical OPLL involving the C 2 segment.

Therapeutic Effect of Posterior Decompression, Internal Fixation and Interlaminar Fusion for Severe Osteoporotic Vertebral Fractures and Collapse Complicated with Spinal Canal Encroachment / 广州中医药大学学报

Objective To evaluate the clinical effect of posterior decompression, internal fixation and interlaminar fusion for the treatment of severe osteoporotic vertebral fracture and collapse complicated with spinal canal encroachment. Methods A retrospective study was carried out in 27 cases of severe osteoporotic vertebral fractures complicated with spinal canal encroachment. The patients were treated with posterior decompression, internal fixation and interlaminar fusion during the period from January 1, 2009 to December 31, 2014. All patients were given vertebral pedicle screw fixation after pedicle augmentation with bone cement. The pain scores of visual analogue scale(VAS), Oswestry Disability Index(ODI), Cobb angle , thoracolumbar Cobb angle and the recovery of neurological function(estimated by Frankel grading system) of the patients were compared beforeoperation, one week after operation and at the end of follow-up. The incidences of internal fixation failure, adjacent vertebral fracture and bone cement leakage also were recorded. Results The patients were followed up for an average of 27 months. The spinal canal occupation rate caused by fracture fragment of posterior vertebral wall was 27.41%~63.85%, with an average of(43.24 ± 10.61)%. Postoperative VAS pain scores, ODI, Cobb angle and thoracolumbar Cobb angle were statistically different from those before operation (P 0.05). In respect of Frankel grading of neurological function at the end of the follow-up, 6 cases were in grade D and 19 cases were in grade E, but the differences were insignificant compared with those before operation (P > 0.05). None of the patients had surgical site infection, screw looseness or breakage, or rod breakage during the follow-up period. There were 8 patients with asymptomatic bone cement leakage after operation. Vertebral compression fractures recurred in 5 patients, of which 2 had adjacent vertebral fractures and 3 had non -adjacent segment. Conclusion The therapy of posterior decompression, internal fixation and interlaminar fusion is effective for the treatment of severe osteoporotic vertebral fracture and collapse complicated with spinal canal encroachment by obviously relieving pain, improving the physiological function of the spine and stabilizing the spine.

Stability and interbody fusion of augmented pedicle screws with bone cement for lumbar spondylolisthesis accompanied with osteoporosis / 中国组织工程研究

BACKGROUND: In lumbar spondylolisthesis patients with severe osteoporosis, screw is easily loose and pul s out during reposition, or loss of reduction and internal fixation failure easily occur after repair. Therefore, it is very important to elevate the intensity of pedicle screw fixation during repair. At present, few studies concern application of bone cement screw enhancement technology in lumbar spondylolisthesis patients with osteoporosis. OBJECTIVE: To investigate the clinical value of augmented pedicle screw with polymethylmethacrylate for lumbar spondylolisthesis accompanied with osteoporosis. METHODS: From June 2009 to June 2011, 27 patients suffering from lumbar spondylolisthesis accompanied with osteoporosis were included in this retrospective study. These patients received augmented pedicle screw with polymethylmethacrylate. The levels of disability and pain were evaluated by Oswestry Disability Index and visual analog scale. The internal fixation and fusion were evaluated by radiological findings. Al complications were recorded. RESULTS AND CONCLUSION: Al cases were fol owed up for 15-37 months. Oswestry Disability Index and visual analog scale scores were significantly better in final fol ow-up than that pre-treatment (P < 0.05). Imaging results revealed that bone cement tightly connected to bone interface. The position of screw and bone cement was good. Symptomatic bone cement leakage was not found. No fixation failure was detected during final fol ow-up. Al patients achieved interbody fusion. These results suggested that polymethylmethacrylate bone cement could increase the gripping force of the pedicle screw in osteoporotic vertebral body. It is safe and effective to treat spondylolisthesis accompanied with osteoporosis with augmented pedicle screws. Satisfactory fixation stability and interbody fusion can be obtained.

Change rules and correlation between bone mass, bone turnover markers and estrogen levels in different periods of ovariectomized rats / 中国组织工程研究

BACKGROUND:There are so many studies about ovariectomized rats at present, but the research on the change rules of bone mass, bone turnover markers, estrogen levels and their correlation in different periods of ovariectomized rats is rarely reported. OBJECTIVE:To analyze the change rules of bone mass, bone turnover markers, estrogen level and their correlation in different periods of ovariectomized rats. METHODS: Thirty-four 3-month-old female Sprague Dawley rats were randomly divided into three groups: baseline group, ovariectomized group and sham operated group. At the beginning of the experiment, the rats in the baseline group were sacrificed, then rats in the ovariectomized group and sham operated group were executed at 4, 8, 12 weeks postoperative respectively. The bone mineral density, bone mass content, area of different zones of the L1-3 lumbar vertebrae and femurs were detected by dual-energy X-ray absorption method, and meanwhile the serum levels of type I procolagen amino-terminal pro-peptide, I colagen carboxy-terminal peptide and estrogen were determined by ELISA. At last, we analyzed the correlation between body mass, bone mineral densityin vitro, type I procolagen amino-terminal pro-peptide, I colagen carboxy-terminal peptide and estrogen levels and the age of ovariectomized rats. RESULTS AND CONCLUSION: (1) The bone mineral density and bone mass content of the lumbar vertebral and femurs in the ovariectomized group were significantly lower than those in the sham operated group and baseline group at the 4th week after operation (P < 0.05). The bone mineral density and bone mass content in the ovariectomized group were ameliorated obviously at the 8th and 12th weeks compared with those at the 4th week after operation (P < 0.05). The bone mass loss was highest in the L1 and intertrochanteric regions. (2) Serum levels of type I procolagen amino-terminal pro-peptide and I colagen carboxy-terminal peptide in the ovariectomized group were significantly higher than those in the baseline group and sham operated group at the 4th week after operation, but there was no difference at the 8th and 12th weeks. (3) The serum estrogen level in the ovariectomized group was prominently lower than that in the sham operated group and baseline group at the 8th and 12th weeks after operation (P < 0.01 at the 8th week,P < 0.05 at the 12th week). (4) The age was positively correlated with body mass and bone mineral density of the lumbar vertebrae and femursin vitro, while the serum levels of type I procolagen amino-terminal pro-peptide and I colagen carboxy-terminal peptide were negatively correlated with the bone mineral density of the lumbar vertebrae and femurs in vitro (P < 0.01). These results suggested that the bone mass of the lumbar vertebrae and femurs in ovariectomized rats was decreased rapidly firstly, and then rose slowly with time; the bone mass in the L1 and intertrochanteric regions lost seriously; the bone turnover markers showed a significant increase at the beginning of ovariectomy and reduced gradualy to normal condition, while the estrogen level was increased at the first month after ovariectomy and then decreased rapidly. In addition, the body mass, bone turnover markers and estrogen level were associated with the change of bone mass.

Establishment of a rat model of lumbar nerve root compression via modified unilateral hemilaminectomy approach / 中国实验动物学报

Objective To explore the characteristics and advantages of the rat model of lumbar nerve root com -pression established via modified hemilaminectomy approach .Methods Forty Sprague Dawley ( SD) rats were randomly divided into two groups ( experimental group and control group ) for establishing a rat model of lumbar nerve root compres-sion.Modified hemilaminectomy apprpoach was used in the experimental group , while total laminectomy was applied in the control group.Duration of operation, estimated blood loss, wound healing status, postoperative mortality, motor function of the lower extremities , pathological changes and the gray level of cytoplasmic TNF-αand IL-1 expression were observed to e-valuate the characteristics and reliability of the two operation approaches in establishing a rat model of lumbar nerve root compression.Results Compared with the control group , duration of operation , estimated blood loss , wound healing sta-tus, postoperative mortality were significantly better in the experimental group (P<0.01), whereas there was non-signifi-cant difference between two groups with regard to motor function of the lower extremities , pathological changes and gray lev-el of the cytoplasmic expression of TNF-αand IL-1 between the two groups .Moreover, the soft tissue structural alterations were reduced in the experimental group , which might be helpful for the rat postoperative rehabilitation .Conclusions Modified hemilaminectomy approach is a reliable alternative method for establishing a rat model of lumbar nerve root com -pression, which is beneficial to shorten the operative time , improve wound healing status , reduce estimated blood loss and damages of soft tissue , and decrease mortality rate .Moreover , this modified method is more consistent with the principles of animal ethics .

Comparison of the effects of gastric gavage and intramuscular injection of prednisone on bone mineral density, skeletal biomechanical properties and bone metabolism in rats / 中国实验动物学报

Objective To compare the effects of gastric gavage and intramuscular injection of prednisone on the bone mineral density, skeletal biomechanical properties and bone metabolism in rats.Methods A total of 45 SPF rats were randomly divided into three groups:normal group, intragastric administration group, and intramuscular injection group.The normal group, as a control group, was administrated with normal saline 2 mL per day, both the intragastric administration group and i.m.injec-tion group received prednisone 0.5 mg/(kg.d) for 12 weeks.All rats were examined for bone mineral density (BMD) and the level of serum β-CTX and PINP.The femoral cortical biomechanical properties ( elastic load, maximal load, rupturing load) were measured by three point bending test.Results After 12 weeks, compared with the normal group, BMD and elastic load, maximal load, and rupturing load of the femur were significantly decreased.Compared with the intragastric gavage group, BMD was significantly decreased, while the elastic load, maximal load, and rupturing load of the femur were not significantly changed in the i.m.injection group (P＜0.05 for all).Compared with the normal group, the level of serum β-CTX was significantly raised (P＜0.05) and the level of serum PINP was significantly decreased (P＜0.05).Compared with the intragastric gavage group, the level of serumβ-CTX was also significantly raised (P＜0.05), the level of serum PINP was significantly decreased (P＜0.05), the bone trabecula and hemopoietic tissue were obviously decreased, while the adipose tissue increased obviously. Conclusions Both intragastric gavage and intramuscular injection of prednisone affect the level of BMD, skeletal biomechanical properties and bone metabolism.However, i.m.injection of prednisone decreases the BMD and bone strength more significantly, leading to a higher bone turnover with increased bone resorption, and leads to osteoporosis earlier.Our results may suggest that oral administration of prednisone is more safe in clinical treatment.

Effect of Vertebral Plate Resection and Disc Excision from Posterior Approach Combined with Lumbar Interbody Fusion for Treatment of Lumbar Disc Herniation Associated with Lumbar Instability / 广州中医药大学学报

【Objective】To assess the indications and therapeutic effect of surgical treatment for lumbar disc herniation(LDH) associated with lumbar degenerative instability(LDI).【Methods】Fifty-eight LDH associated with LDI patients,which were ineffective after strictly conservative treatment or simple decompression with disc excision,received lumbar vertebral plate resection and disc excision from posterior approach,and transpedicular screw fixation combined with posterior lumbar interbody fusion.【Results】A averaged 13-month follow-up was carried out in 54 patients.The therapeutic effect assessed by Japanese Orthopaedics Association(JOA) was as follows: excellent in 37 patients,good in 13,ordinary in 4,and the excellent +good rate was 92.59%.The results of X radiography 3 months after the operation showed that lumbar interbody fusion was successful in 52 patients,the infusion rating being 96.30%.【Conclusion】Lumbar vertebral plate resection and disc excision from posterior approach,and transpedicular screw fixation combined with posterior lumbar interbody fusion are effective for the treatment of LDH associated with LDI.